####018005497#### FXUS62 KCAE 171734 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 134 PM EDT Sat May 17 2025 .SYNOPSIS... Rain chances diminish this afternoon with partial clearing from northwest to southeast before more mid to high level cloudiness arrives tonight. Sunday looks warm and humid with a few afternoon and evening showers and thunderstorms possible, especially in the CSRA. The next significant chance of rain comes during the middle of next week with warm temperatures persisting until then. Temperatures are then forecast to decrease late next week. && .NEAR TERM /THROUGH TONIGHT/... Key Message(s): - Rain chances diminish with partial clearing this afternoon. - Clouds move back in during the overnight hours. The radar this afternoon is showing light returns across Burke and Richmond counties but observations do not suggest much, if any, precipitation is reaching the ground. This should be the end of any rain chances for the rest of the day once it moves out of the CSRA. Satellite imagery shows clearing skies across our northern and western counties, and partial clearing is expected for the remainder of the day. The primary concern this afternoon will be the potential for gusty southwesterly winds, especially on area lakes. Webcams and latest near lake observations do not support the issuance of a Lake Wind Advisory with this package but trends will be monitored. The persistent cloud cover this morning has limited warming, therefore highs were decreased and now range from the mid-80s to around 90 degrees. Guidance shows mid to high level cloudiness returning tonight, which will likewise limit radiational cooling though it will likely be cooler than last night. Temperatures by daybreak should range from the mid-60s to near 70 degrees. && .SHORT TERM /SUNDAY THROUGH WEDNESDAY/... Key Message(s): - Warming trend through Tuesday. - Chances for afternoon showers and thunderstorms each afternoon, especially Wednesday. The warming trend is slated to continue tomorrow as upper heights atop the SE CONUS begin their upward creep and ongoing wsw llvl flow will aid in boosting maximums into the upper 80s. At this juncture, there is enough support within the latest CAMs and SPC HREF output to maintain small diurnally enhanced pop acrs the CSRA, closer to the SPC day 2 marginal swath. 90 degree readings are slated to return to the fcst Monday afternoon as a shearing s/wv attempts to top building ridge axis off to our west. Will have to monitor this feature as we start off the work week but for now, the sensible wx with feature scattered afternoon thunderstorms cwfawide. Potentially the warmest day of the week is on tap for Tuesday featuring lower 90s along and south of I-20. With the axis of the low amplitude upper ridge poking up atop the region, there is the potential for the atmosphere to remain capped from AGS- CAE. Solid chance pop on tap for Wednesday thanks to the approach and passage of weakly forced frontal zone. && .LONG TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... Key Message(s): - Drier and cooler airmass overspreading the region. The 17/12 UTC suite of extended range guidance and ensembles continues to advertise the influx of a continental airmass in the wake of a cold frontal passage to start off the period. Underneath broad cyclonic flow and a briefly tightening pressure gradient, developing breezy conditions are on tap for Thursday as max temperature may only top out near 80. The combination of weak surface ridging and ongoing dry NW flow aloft is expected to provide sunshine to round out the workweek with developing llvl return flow on Saturday and a corresponding boost to maximum temperature closer to climo. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... Generally VFR Conditions Expected.... Skies are overcast at the terminals at midday, but clouds are starting to break up at CAE/CUB and this trend should continue at all terminals this afternoon as cloudiness moves further south and east. Surface winds are expected to increase for the afternoon and early evening hours and will be gusty at times, diminishing after sunset. Guidance suggests additional high level cloudiness will move in tonight but ceiling restrictions are not expected. EXTENDED AVIATION OUTLOOK... Mainly VFR conditions expected through the period barring low end chances for showers and thunderstorms each afternoon which could cause brief restrictions. && .HYDROLOGY... After another rise back into Action Stage early this morning, the Congaree River at Columbia is quickly falling. If trends continue, and pending any further upstream releases, the Flood Advisory will be cancelled later today. Further downstream, both Carolina Eastman and Congaree National Park remain in Minor flood stage and Flood Warnings continue there. The river levels will gradually fall through the weekend and should fall below flood stage by Monday morning. Elsewhere, the Flood Warning that was in effect for parts of the Edisto River will expire as scheduled with this forecast package as the river continues to slowly recede. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...None. GA...None. && $$ ####018005576#### FXUS65 KFGZ 171736 AFDFGZ Area Forecast Discussion National Weather Service Flagstaff AZ 1036 AM MST Sat May 17 2025 .SYNOPSIS...Gusty winds and cool weather looks to set in today and Sunday, leading to areas of critical fire weather conditions. Slight chance for showers across far northern Arizona tonight through Monday as well. Warm and dry conditions expected to return for much of next week. && .UPDATE...A trough is moving down from the Pacific Northwest and into the Great Basin this morning, eventually entering our area tonight. Ahead of the trough we see a tightening of the pressure gradient, resulting in gusty winds later this morning and continuing through the day. This system has limited moisture and over the past several days has seemed to become drier and drier. Best chances for a light shower look to be towards the AZ/UT border later tonight. Made some minor updates to the PoPs but overall the forecast is in good shape. && .PREV DISCUSSION /339 AM MST/...A deep trough is beginning to descend from the Great Basin region today, so this will be the start of cooler temperatures and windier conditions. Daytime highs only look to be a few degrees cooler than yesterday, but expect afternoon wind speeds to increase out of the southwest across much of our CWA. The Wind Advisory that was issued yesterday for this afternoon has been extended to also include the Little Colorado River Valley and Painted Desert. This product is set to begin at 11 AM MST (12 PM MDT) and continue through 11 PM MST (Midnight MDT). Hi-res guidance does suggest winds remaining elevated overnight as the trough axis slides across the state, but they should drop below our advisory criteria. While we are on the topic of products, a Red Flag Warning remains in effect for the Little Colorado River Valley and White Mountains this afternoon/evening. The weather doesn't stop there though...this disturbance is carrying moisture with it, but the bulk of the precipitation appears to stay north of Arizona. Best chances for showers/thunderstorms will be across the AZ/UT border late tonight through Sunday afternoon. Model guidance suggests a secondary trough axis sliding down Sunday night through Monday, but this system continues to look less and less exciting with each model run for northern Arizona. Winds will remain gusty ahead of this next system, especially across eastern Arizona. The previous Fire Weather Watch has been upgraded to a Red Flag Warning for Sunday afternoon for the Little Colorado River Valley in Apache County. There could be a few isolated showers/thunderstorms across the Four Corners on Sunday afternoon/evening, with additional activity possible on Monday along our eastern border. There could be a need for additional Wind and Fire Weather related products for Monday afternoon, but we'll assess that further in upcoming grid updates. Tuesday Onward...A quick return of warm and dry weather is in store for next week as the previously mentioned trough moves out of the region. Expect daytime highs to reach 5-15 degrees above normal for the second half of the upcoming work-week, along with typical spring-like breezes. && .AVIATION...Saturday 17/18Z through Sunday 18/18Z...Primarily VFR conditions, though smoke could reduce visibility locally near and downwind of Greer (in eastern Arizona) and the Blind fire (southeast of KFLG). ISO-SCT -SHRA will develop after 06-09Z primarily north of the I-40 corridor. Winds are SW 15-25 kts gusting to 30-40 kts. Saturday night will see local winds SW 10-20 kts gusting to 30 kts downwind of terrain features. OUTLOOK...Sunday 18/18Z through Tuesday 20/18Z...VFR conditions prevailing, though smoke could reduce visibility near and downwind of wildfires. ISO -SHRA/-TSRA will continue through Monday afternoon, before continued risk for ISO-SCT -SHRA/-TSRA returns 12Z Monday-00Z Tuesday primarily in far northeastern AZ. Winds are W 15- 25 kts gusting 30-40 kts on Sunday, turning W-NW Monday. && .FIRE WEATHER...Today and Sunday...Dry today with minimum RH values mostly below 15%. Southwest winds increase to 15-25 mph gusting 30- 40 mph this afternoon, and will persist through the overnight hours along the Mogollon Rim and White Mountains. A Red Flag Warning is in effect today for the Little Colorado River Valley and White Mountains. Breezy west-southwest winds continue Sunday, strongest in eastern Arizona and a Red Flag Warning is in effect for the Little Colorado River Valley in Apache County. Elsewhere, RH will trend upward Sunday along with a chance of showers/thunderstorms over the northern third of the state. Monday through Wednesday...Cooler Monday with a chance of showers mainly in northeast Arizona. West-northwest winds 15-25 mph, with near-critical fire weather in eastern Arizona. Lighter winds, drier conditions and turning much warmer Tuesday and Wednesday. && .FGZ WATCHES/WARNINGS/ADVISORIES... Wind Advisory until 11 PM MST /midnight MDT/ this evening for AZZ004-006>008-012>015-040. Red Flag Warning until 7 PM MST /8 PM MDT/ this evening for AZZ112>114-117-140. Red Flag Warning from 11 AM to 7 PM MST Sunday for AZZ114. && $$ PUBLIC...Meola/Konieczny AVIATION...Lewandowski FIRE WEATHER...JJ For Northern Arizona weather information visit weather.gov/flagstaff ####018006339#### FXUS65 KGJT 171736 AFDGJT Area Forecast Discussion National Weather Service Grand Junction CO 1136 AM MDT Sat May 17 2025 .KEY MESSAGES... - Warm and breezy conditions are expected today, with a chance for isolated showers or storms on the higher terrain north of I-70. - Southeast Utah and southwest Colorado will see elevated to critical fire weather conditions this afternoon, where fuels have been deemed critical. A Red Flag Warning remains in effect for southeast and east-central Utah. - Cooler and unsettled conditions return for Sunday through Tuesday, with mountain snow and valley rain expected. && .SHORT TERM /THROUGH SUNDAY/... Issued at 326 AM MDT Sat May 17 2025 Mid and upper level moisture is streaming across the northern half of the region this morning, spawning increased cloud cover and virga showers. Thus far, little if any precipitation has reached the ground despite the returns on radar, but some stronger, gusty winds have been recorded. This increased moisture and cloud cover has resulted in milder temperatures this morning, particularly for areas north of the San Juans. To the south, a punch of drier air is working in, resulting in comparatively lower dew points and temperatures about where they were at this time last night. This punch of dry air is expected to bring single digit and low teens humidity values to southeast Utah and southwest Colorado this afternoon. In addition, southwesterly winds will be on the increase as the trough to our west strengthens and the pressure gradient begins to tighten up aloft. With gusts of 25-35 mph expected, this will result in elevated to borderline critical fire weather conditions this afternoon where fuels are critical. A Red Flag Warning is in effect for southeast and east-central Utah (UT Fire Weather Zones 490 and 491) from noon to 8PM. While fuels are currently not deemed critical across most of southwest Colorado, that doesn't mean that localized critical fire weather conditions aren't possible. Caution is urged and outdoor burning is not recommended given the drier and breezy to windy conditions. Enough moisture will remain in place across northwest Colorado and northeast Utah to result in a few orographic shower over the higher terrain, with maybe a slight expansion in coverage this evening as a small wave in the southwesterly flow moves through. Otherwise, breezy, warm, and quiet conditions will be the name of the game today. Temperatures will climb to around 5 degrees above normal. Winds will continue to pick up through the night as the trough strengthens and an 70-80 knot jet moves overhead. However, moisture will also be on the increase. So while tomorrow will see stronger winds, the fire weather concerns will be limited. Shower activity is expected to break out around daybreak tomorrow, favoring the higher terrain along and south of I-70 as the best energy at the base of the trough tracks over the Four Corners. Additionally, a cold front will push through during the afternoon, bringing much cooler temperatures, with highs expected to be around 10 degrees cooler than today, and more widespread precipitation. With moisture and a much cooler airmass in place, accumulating snow above 9K feet is expected. At this point, with this event lasting through Tuesday morning, snow totals are looking borderline advisory. There's still enough uncertainty that I am holding off on issuing highlights with this package. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... Issued at 326 AM MDT Sat May 17 2025 A deep upper-level trough will be overhead on Sunday night, bringing widespread precipitation across the CWA, with mountain snow and valley rain. Uncertainty grows on Monday as a northern closed low descends southwards through the trough. Lacking moisture with this low (PWAT's 90-130% of normal) will result in primarily orographically-driven showers, though the further reduced temperatures associated with the system would favor more mountain snow and valley rain as snow levels drop to around to 7.5-8.5 kft. The rapidly evolving upper-level pattern regarding the slow-moving trough and the southwards-moving closed low leaves the early-week weather difficult to pinpoint. One way or another, widespread precipitation favoring higher terrain where orographics can better support storms is expected to occur. However, timing and intensity remains unclear, and future forecast discussions should provide more clarity on the details as more short-range model guidance becomes available. For later in the period, models are still indicating ridging trying to build into the Desert Southwest, resulting in a return to warmer and drier conditions. && .AVIATION /18Z TAFS THROUGH 18Z SUNDAY/... Issued at 1136 AM MDT Sat May 17 2025 Gusts have already begun picking up at KASE and KTEX, and are expected to pick up across the rest of the region over the next couple hours. These gusts will peak around 25-30 mph, generally in the mid to late afternoon. Tomorrow, along with more gusty winds, showers will begin impacting many terminals around noon MDT. KMTJ and KTEX are the most likely locations to see cigs reach ILS breakpoints, and vis may drop to MVFR wherever showers are present. && .FIRE WEATHER... Issued at 326 AM MDT Sat May 17 2025 Dry and breezy conditions are expected this afternoon across southeast Utah and southwest Colorado, resulting in elevated to critical fire weather conditions. A Red Flag Warning remains in place for Utah Fire Weather Zones 490 and 491. Stronger southwesterly winds with gusts up to 40 mph are expected tomorrow, but enough moisture will be in place to keep humidities above critical thresholds. Cooler and wetter conditions are expected early next week, before a return to warm and dry weather Wednesday onward. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...None. UT...Red Flag Warning until 8 PM MDT this evening for UTZ490-491. && $$ SHORT TERM...BGB LONG TERM...TGJT AVIATION...TGJT FIRE WEATHER...BGB ####018006218#### FXUS62 KRAH 171736 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 137 PM EDT Sat May 17 2025 .SYNOPSIS... A cold front will cross NC this evening, then stall to our south tonight. Cooler and drier high pressure will extend into the region on Sunday and Monday. The front will lift north across the Carolinas as a warm front on Tuesday. && .NEAR TERM /THROUGH TONIGHT/... As of 137 PM Saturday... Early afternoon satellite imagery shows clearing skies across the area. Light showers remain across the Sandhills/southern Coastal Plain (remnants from the early morning convection) but the rest of the area remains dry. A gradual decrease in dewpoints has been noted across the area with mid 60s becoming increasingly common as of 17Z. Temperatures generally range from the upper 70s in the north, to the lower 80s in the south. A synoptic cold front remains to our northwest, and is still progged to move through late this afternoon/early evening. By the time is does, the plume of deeper moisture and elevated PW's will be positioned across far eastern NC. While some isolated shower development can't be ruled out, especially in the immediate vicinity of the front itself where surface convergence is maximized, widespread shower development does not appear favorable. NCAR ensemble and the vast majority of the 12Z HREF members keep the area dry and aside from some pockets of 10 percent PoPs between 21Z-01Z, the forecast will remain dry for the rest of the afternoon/evening/overnight. With lower dewpoints arriving area-wide later today, expect cooler temperatures tonight with lows falling into the low to mid 60s. && .SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/... As of 320 AM Saturday... * Warm, but drier with gusty northwesterly winds during the afternoon. Sunday will likely be largely quiet behind the frontal passage from Saturday night. The incoming airmass isn't particularly much cooler, but it will be noticeably drier as dew points drop into the mid 50s. Momentum just above a shallow inversion Sun morning will quickly mix out and produce some gusty winds 15 to 25 mph as temperatures rise into the 80s, near 90 degrees across the NC/SC border. Convective debris and remnant MCVs from upstream storms riding the now stationary front to our south, should result in a mostly cloudy day as multi-layered clouds stream across the area. Lows will settle in the 60s outside of the far northern Piedmont where upper 50s will be possible. && .LONG TERM /MONDAY THROUGH FRIDAY/... As of 320 AM Saturday... * A sharpening warm front lifting trough the forecast area will bring unsettled weather through Wednesday. * Cooler and drier weather expected Thursday and Friday behind a cold frontal passage late Wednesday. A couple mid-level closed lows situated over the northern Plains and the Northeast will create broad shortwave ridging from the Gulf coast up through the Great Lakes and extend out over the Southeast. The stalled boundary over GA/SC Mon morning is expected to ripple northward through the late afternoon, but how far north is fairly uncertain. South of this front will exist a moderately unstable airmass where dew points in the mid 60s will contribute to 1000-2000 J/kg of SBCAPE. Most deterministic guidance has a convective induced disturbance riding the ridge Mon afternoon and into the Southeast by peak heating with enhanced westerlies contributing to 30 to 40 kts of 0-6km shear. The position of the front rippling northward Mon afternoon will delineate the northward expect of showers/storms through Mon evening. By Tues morning, the warm front will continue to lift further into our area and sharpen as it meets a backdoor front sliding down through the Mid-Atlantic. Frontogenetic forcing and strengthening WAA aloft will contribute to blossoming area of rain and embedded showers/storms along and north of this front Tues evening and overnight. This regime should slowly lift into VA into Wed morning which may lead to a brief lull is precipitation until a cold frontal passage brings another rounds of showers and potential storms. Noticeably cooler air will spread into the southern Mid-Atlantic behind this frontal passage with its source region stemming from central Quebec where a maritime Polar airmass is progged to located. Cooler and mostly drier weather is expected to continue through Friday where highs are forecast to be 5 to 10 degrees below normal. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... As of 1250 PM Saturday... This morning's showers have dwindled or shifted east of the forecast area, although a few showers will remain possible later today through the evening (roughly 20z-03z), mainly in the S (near FAY). Overall, the risk of sub-VFR conditions in the area is very low through the next 24 hours, even in and near any of these isolated showers, and most areas will stay dry through midday Sun with just areas of mid and high level clouds based above 7kft AGL passing overhead and no vsby restrictions. We will, however, have wind gusts as high as around 22-28 kts through 23z from the SW, shifting to W, and after that time, we'll see a risk of low level wind shear lasting through much of the night (until around 08z-10z) with 2kft AGL winds from the W then NW at 35-40 kts slowly declining to around 25 kts before dawn. Looking beyond 18z Sun, VFR conditions will likely hold through Sun evening, however there is a chance of some sub-VFR fog/stratus esp across the S and W early Tue morning and a better chance early Wed morning. A few storms are possible Mon evening/night, with a better chance Tue night through Wed night, with mainly VFR conditions returning for Thu. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Leins/Blaes NEAR TERM...Leins SHORT TERM...Swiggett LONG TERM...Swiggett AVIATION...Hartfield ####018004041#### FXUS64 KMEG 171736 AFDMEG Area Forecast Discussion National Weather Service Memphis TN 1236 PM CDT Sat May 17 2025 ...New AVIATION... .KEY MESSAGES... Updated at 1236 PM CDT Sat May 17 2025 - Dry and warm conditions will prevail over the Midsouth today. - Thunderstorms will return late tonight. There is a Marginal Risk for severe thunderstorms over most of the Midsouth. The primary risks will be damaging winds and large hail. - An unsettled weather pattern will continue through Tuesday. Cooler and less humid conditions will follow for Wednesday through Friday. && .DISCUSSION... (Today through Friday) Issued at 632 AM CDT Sat May 17 2025 A dynamic and progressive upper level pattern will prevail over the U.S. through the middle of next week. Early morning GOES water vapor imagery showed a closed northern branch low centered over WI. This feature will lift through the Great Lakes today, as upstream ridging over the Great Plains edges into the MS River Valley. Under this ridging, Midsouth temps will average 3 to 5 degrees above normal. A weak stationary front will settle over north MS today, separating slightly less humid air to the north from subtropical air to the south. Out west, thunderstorms from central TX to OK will develop in tandem with a shortwave ejecting through the southern plains, out ahead of a longwave trough over the Great Basin. These storms will lift into the lower MS River Valley, about the time midlevel heights build in advance the progressive Great Basin trough. HREF joint probabilities of surface cape >= 1000 J/kg and 40kt of deep layer shear is 20% or less, compared to 90% late last night. The main take away: Tonight's storms should pose less of a severe risk relative to Friday night's storms. Upper level ridging will prevail Sunday, but 70s dewpoints will aid in daytime instability and weakening convective inhibition. By late Sunday afternoon, the ridge axis will lift east, allowing diffluent southwesterly flow aloft to overspread the Midsouth, maintaining our convective potential Sunday night. Monday will see the western U.S. upper low emerge into the Plains. Ridging aloft and strong onshore flow will allow surface-based instability to build thruogh the lower MS River Valley Monday afternoon, prior to a lead shortwave ejecting through Ozarks. Global models are in reasonable consensus in showing the upper low lifting through the middle MS River Valley Tuesday evening, Strong dynamical forcing appears likely, with convection occurring along and ahead of a progressive surface dryline. At this time, it appears that Tuesday will holds the highest chance of severe storms next week. Following a busy four day period, the Midsouth will finally get a break from storms, as less humid continental high pressure settles in under northwest flow aloft. PWB && .AVIATION... (18Z TAFS) Issued at 1236 PM CDT Sat May 17 2025 Predominantly VFR forecast expected with some impacts early tomorrow morning from showers and storms. Very clear skies, with the exception of a few cirrus clouds, and light winds will prevail through this afternoon. Storms from the west will approach north Mississippi tonight with showers and possibly a few thunderstorms up to JBR. Added TEMPO groups where confidence is highest in weather related hazards at MEM/TUP and PROB30s for rain showers at JBR/MKL. Forecast confidence is somewhat low for tonight as models have been back and forth regarding the timing and extent of MVFR impacts. Thunder could occur at JBR/MEM but confidence was too low to include at this time. This forecast will likely change in the coming hours as models refine their outlook on tonight. && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$ PUBLIC FORECAST...PWB AVIATION...JAB ####018010265#### FXUS63 KSGF 171737 AFDSGF Area Forecast Discussion National Weather Service Springfield MO 1237 PM CDT Sat May 17 2025 .KEY MESSAGES... - 50-70% chance for showers and thunderstorms tonight into Sunday morning. A Marginal (1 of 5) to Slight (2 of 5) Risk exists for a few thunderstorms that may become capable of producing wind gusts up to 60 mph and hail up to the size of quarters. - The unsettled weather pattern will continue across the area early next week. This includes the potential for strong to severe thunderstorms in addition to localized heavy rainfall and flooding. Uncertainty remains in the exact storm mode and evolution, which will impact main hazards. - Active pattern is forecast to end after Tuesday, with mostly dry and cooler temperatures Wednesday onwards. && .SHORT TERM /THROUGH TONIGHT/... Issued at 345 AM CDT Sat May 17 2025 Current water vapor imagery depicts a hexagonal spinner over MN/WI consistent with a deep vertically stacked low pressure system. South of the low, mid-level dry air is noted within a belt of 80-100 kt westerlies originating from a shortwave over the Baja Peninsula. Extending from the stacked surface low are two cold fronts that are currently draped from MI through MO, and into the southern Plains states. The second cold front will bring northwesterly winds, cooler temperatures this morning (lows in the lower to middle 50s), and drier air. The front is forecast to stall just south of the MO/AR border, so high temperatures will range from the middle 70s in central MO, to the lower 80s along the southern border. Marginal to Slight Risk for severe storms tonight: The stalled cold front boundary is forecast to very slowly lift back north as an effective warm front starting this afternoon as shortwave energy overspreads TX/OK. While the surface front will still be south of the border tonight, the 850 mb front will lift through southern MO. Associated southerly flow will then advect warm and moist air over the surface boundary, bringing 500-1000 J/kg MUCAPE along and south of a Nevada to Eminence line as noted by the 00Z HREF. Warm air advection and isentropic upglide over the front should then force showers and thunderstorms in far southwest MO after 7 PM. These will then spread northeastward along with the lifting warm front, bringing 50-70% chances for rain. Modest 500 mb flow associated with the incoming shortwave should generate 25-40 kts of effective shear, according to RAP forecast soundings. Thus, some thunderstorms may become organized enough to produce wind gusts up to 60 mph, and with mid-level lapse rates at 7-8 C/km and elevated instability, hail up to the size of quarters are also possible. Later overnight, the remnants of storms over southern KS/northern OK may also make it into southern MO. These storms would also pose a wind and hail threat late tonight into early Sunday morning, depending on their longevity. Slight (2 of 5) Risk for severe thunderstorms Sunday: Elevated showers and thunderstorms may continue Sunday morning and into the afternoon along the lifting warm front. Behind the warm front, instability will gradually increase and overspread the area as temperatures warm into the upper 70s and lower 80s and dewpoints in the middle 60s. The HREF mean depicts 1500-2500 J/kg MLCAPE, and RAP/HRRR suggests upwards of 2500-4000 J/kg MUCAPE in extreme SW MO and SE KS. Deep layer shear is also expected to increase to 40-50 kts as stronger southeasterly surface flow undercuts persistent westerly mid- level flow. Therefore, the environment during the day Sunday will be primed for severe weather if storms can continue. Forecast soundings depict 25 to 50 J/kg of capping during the day, though persistent 850 mb warm air advection may promote elevated convection. However, rising heights during the day may suppress the weak synoptic forcing of WAA. Thus, severe thunderstorm development is uncertain during the day Sunday. If storms are able to initiate, supercells will be possible with hail up to golf ball size and wind gusts up to 60 mph. If these happen to be surface-based, a tornado or two cannot be ruled out, especially in the vicinity of the warm front where hodographs will be a bit more curved producing 100-150 m2/s2 0-1 km SRH. Though storm development during the day is uncertain, there will more likely be storms Sunday night. && .LONG TERM /SUNDAY THROUGH FRIDAY/... Issued at 345 AM CDT Sat May 17 2025 Slight (2 of 5) Risk for severe thunderstorms Sunday night: While the airmass over the Ozarks will be deeply unstable and sheared, forcing for ascent and convective initiation along and south of the warm front is weak and uncertain. There is a much higher likelihood for storms to develop along the dryline across central KS/OK during the day. These will then progress eastward into our area during the evening and overnight hours. Storm mode and evolution for these are still uncertain as CAMs are all over the place. Initial mode in KS/OK will likely be intense discrete supercells given the environment and shear vectors directly perpendicular to the dryline. However, the evolution is uncertain. Discrete supercells could be maintained as shear vectors persist westerly across our area. On the flip side, efficient cold pools and an increase low-level jet could produce an MCS. Then there could always be a mixed mode of both. Time will tell how this shakes out, but the storm mode/evolution will dictate our most likely hazards. If supercells can be maintained, all hazards including hail up to tennis balls, a couple tornadoes, and 60 mph wind gusts will be possible. If an MCS is the dominant mode, wind gusts up to 60 mph, a couple tornadoes (as low-level shear vectors will be westerly promoting a QLCS spin-up threat), and quarter-sized hail will be the main hazards. Enhanced (3 of 5) Risk for severe thunderstorms Monday: The same sort of setup as Sunday will exist Monday, except slightly more amplified and the dryline shifting a bit eastward into east-central KS/OK. Medium-range guidance suggests MUCAPE greater than 3000 J/kg as dewpoints increase to the upper 60s, and deep-layer shear greater than 50 kts as the flow aloft increases ahead of a deepening trough. Therefore, again, storm development is a low-end scenario during the day Monday, with higher chances Monday evening/night as they move in from the west. Hazards will once again be determined by storm mode/evolution, however, with the initiating dryline shifting eastward, there is a larger/longer window for discrete all- hazards supercells (potentially significant hail) late Monday afternoon/early evening before any potential change in evolution. This combined with the amplified instability/shear parameters is leading to an Enhanced (3 of 5) Risk for the western 2/3rds of our forecast area. Slight (2 of 5) Risk for severe thunderstorms Tuesday: As the potent system translates eastward, severe thunderstorms will once again be possible Tuesday. Global models seem to be a bit more progressive with the warm sector forecast to be along and east of Highway 65 after 12 PM Tuesday. With a crashing cold front progged to accompany a deepening upper-level low severe weather is possible as it moves through our CWA Tuesday afternoon. Hazards are currently uncertain, but given the strong frontal forcing, damaging wind gusts look to be a main hazard. Compounding showers and storms could lead to localized flooding: Along with the chances for severe weather each day, the compounding effect if multiple rounds of showers and storms (especially from heavy rain within severe convection) could lead to localized flooding. The EFI is highlighting 0.6-0.8 values with a shift of the day every day through Tuesday. Despite this, the location of any flooding is highly uncertain right now, as it will depend on where storms go. Due to smoothing of timing and location from every model, most areas in our CWA are forecast to see between 2 and 4 inches through Wednesday. However, if MCSs become the dominant storm mode each night, and end up riding the warm front at the nose of the nocturnal low-level jet, there could definitely be banded areas that see well over 4 inches of rain. For example, the experimental MPAS ensemble puts a band of 7-12 inches total precipitation Saturday through Wednesday across central Missouri. This is not to be taken literally, but it does highlight the scenario of multiple MCSs riding a relatively stationary warm front each day/night. Trends will continue to be monitored. Cooler and drier weather Wednesday onwards: After the potent trough kicks through the region, cooler and drier weather are forecast Wednesday onwards. Highs Wednesday are forecast to be in the lower 60s with lows in the middle 40s Wednesday night. These cooler temperatures will then gradually warm to highs in the middle 70s and lows in the upper 50s by Memorial weekend. Some rain chances return Friday and Saturday within a northwesterly flow regime, but details are currently uncertain. && .AVIATION /18Z TAFS THROUGH 18Z SUNDAY/... Issued at 1231 PM CDT Sat May 17 2025 Ceilings will remain VFR through most of the day today with breezy northwesterly winds. A east-southeasterly wind shift will occur after 00z tonight and the chance for showers and thunderstorms starts to increase as well. Models weren't showing ceilings lowering below VFR thresholds, however, they may drop to MVFR briefly if heavy rain does occur in these storms. Put in a PROB30 for TSRA just before midnight. Skies clear before sunrise on Sunday before another chance for rain occurs Sunday afternoon. && .SGF WATCHES/WARNINGS/ADVISORIES... KS...None. MO...None. && $$ SHORT TERM...Price LONG TERM...Price AVIATION...Soria ####018009480#### FXUS61 KBOX 171738 AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 138 PM EDT Sat May 17 2025 .SYNOPSIS... An upper level low pressure over Michigan will be responsible for scattered showers and thunderstorms. Some storms this afternoon in interior Southern New England could become severe. Turning cooler and drier tonight, with blustery conditions also developing on Sunday. Dry to start the week, and a cooling trend sets in Tuesday that will continue through the week. Unsettled weather returns once again in the second half of the week into the weekend. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Key Messages... * A few severe storms possible across western MA/CT after 4-5 pm today but greater areal coverage across northern New England * Much of today may end up dry with partial clearing and highs well up into the 70s to near 80 with some humidity too Details... A complex forecast into this evening...which we will explain below. Low clouds covered much of region at mid-morning...but enough diurnal heating with the strong May sun angle should allow for partial sunshine to develop through the afternoon. Highs should be well into the 70s to near 80 with modest humidity too. The main concern revolves around the convective threat today. The latest guidance is fairly limited with the threat of elevated activity through mid afternoon with better forcing and moisture to our northwest. While a few isolated showers and perhaps an isolated t-storm can not be ruled out...thinking dry weather may prevail across much of the region through mid afternoon. We do expect a modest amount of instability to develop across the interior with MLCapes rising into the 1500-2000 J/KG range. There also will be a fair amount of effective shear on the order of 35 to 45 knots. At the same time...a relatively strong shortwave will be lifting into northern New England. Although we expect a fair amount of instability/shear we will be on the edge of the stronger forcing. So that may keep any activity that develops across our region isolated to scattered with better coverage in northern New England. However...given the amount of instability and shear and storm that develops in western MA/northern CT will be capable of becoming severe with the main threats being localized damaging wind gusts and hail. This also looks to be a rather late show...mainly after 4-5 pm across western MA/CT. This is supported by the CAMs and machine learning guidance tend do have some severe probs into this region...but hint at a better chance to our north. What ever activity develops should weaken this evening...as it out runs better instability/forcing. So while a rumble or two of thunder may survive onto the I-95 corridor...the severe weather threat appears low in this region. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/... Key Messages: * Drier and much less humid tonight, although still some cloud cover around. * Partly to mostly cloudy Sunday, breezy with generally seasonable temps. Hit or miss shower possible north of the Mass Pike. Details: Our weather pattern for tonight into Sunday then becomes more strongly governed by the upper level low over Michigan. This looks to be accompanied by below-average 850 mb temps and still quite a bit of low to midlevel RH. So while we do clear out tonight and trend dry, there could still be at least partly cloudy skies tonight but not the low clouds we've had the last couple nights. The biggest change though is that dewpoints will plummet back into the 40s to low 50s, so a considerably less humid airmass. Sunday is looking partly to mostly cloudy and rather breezy with WNW winds around 10-15 mph with gusts to 20 mph. Couldn't rule out a hit or miss shower north of the Mass Pike Sunday but probably not widespread or capable of washouts. It's possible that adiabatic downsloping could boost areas such as metrowest Boston to around 70 degrees, but highs could struggle to reach the low to mid 60s in interior Southern New England. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... Key Messages: * Dry and seasonable Monday * Cooling trend returns Tuesday through the rest of the week * Another system may bring significant rain and gusty winds to southern New England midweek Details... An upper level low makes its exit offshore towards the Maritimes Monday night. Northwest flow kicks in in its place while the cooler temperatures aloft remain, which will help keep the region cooler and drier; highs Tuesday through Thursday will remain mostly in the 50s and low 60s. Towards the second half of the week, another upper level low is expected to dig into the Great Lakes. An associated surface low is then expected to move up along the east coast towards southern New England. The late spring Nor'Easter would likely bring significant rainfall and gusty winds sometime Wednesday evening through Friday, however, timing still varies greatly in the guidance. Deterministic guidance also still varies significantly on the track of the low's center, and the GEM generally has the system approaching slightly later than the other models do and moves it further to the south of the region. This would keep most of the rain to the south and glance the south coast. Generally, though, the consensus is that the end of next week will be unsettled and cool with continued broad cyclonic flow and cooler temperatures aloft. && .AVIATION /17Z SATURDAY THROUGH WEDNESDAY/... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 18z TAF Update.... This afternoon into tonight...Moderate Confidence. MVFR with localized IFR conditions will probably improve to mainly VFR by late afternoon/early evening in most locations... although some IFR to even LIFR conditions may persist well into the overnight hours towards the south coast/Cape and Islands. The main issue will be the potential for scattered showers and thunderstorms mainly after 20z/21z across interior MA and CT. Forcing is better across northern New England...but any storm that develops in western MA/northern CT into this evening may become strong. The activity should weaken as it approaches the BOS-PVD corridor...probably not until after 00z. Not sure if a few rumbles of thunder survive towards the I-95 corridor...but regardless expect a weakening trend. Most of the activity should dissipate after midnight as winds become West at 5 to 15 knots. Sunday and Sunday night...High Confidence. A scattered to broken deck of clouds are expected Sun into Sun night...but some marginal MVFR cigs will be possible too. Much of this time will be dry...but a few showers will be possible at times Sun into Sun night. West winds on Sun will shift to the NW Sun Night. Winds will gust to between 20 and 25 knots at times and perhaps up to 30 knots in a few spots very late Sun night. KBOS TAF...Moderate Confidence. Main concern is for cluster of weakening scattered showers approaching the terminal 00z. KBDL TAF...Moderate Confidence. Main concern is for a few strong thunderstorms roughly after 20z/21z through 01z/02z. Outlook /Monday through Wednesday/... Monday: VFR. Windy with local gusts up to 30 kt. Monday Night: VFR. Breezy. Tuesday: Mainly VFR, with areas MVFR possible. Breezy. Tuesday Night: Mainly VFR, with local IFR possible. Wednesday: MVFR/IFR conditions possible. Chance SHRA. && .MARINE... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. High confidence overall. Winds and seas remain below SCA levels through tonight. However fog is a concern for boaters this morning, and there could be thunderstorms over the southern waters late this morning to early afternoon. West to northwest winds increase tonight and especially on Sunday to around 20-25 kt, with seas increasing to 3 to 5 ft. Small craft advisories have been hoisted for Sunday and into Sunday night for the southern waters. Conditions look borderline on the eastern waters for SCAs but could be considered in later updates. Outlook /Sunday Night through Wednesday/... Sunday Night through Monday: Winds less than 25 kt. Areas of seas approaching 5 ft. Monday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Slight chance of rain showers. Tuesday through Tuesday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Wednesday: Winds less than 25 kt. Seas up to 5 ft. Slight chance of rain showers. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory from 2 AM to 8 PM EDT Monday for ANZ230- 231-236-250-251. Small Craft Advisory from 8 AM Sunday to 8 PM EDT Monday for ANZ232>235-237-254>256. && $$ SYNOPSIS...Loconto NEAR TERM...Frank SHORT TERM...Loconto LONG TERM...Hrencecin AVIATION...Frank/Hrencecin MARINE...Loconto/Hrencecin ####018004428#### FXUS64 KLIX 171738 AFDLIX Area Forecast Discussion National Weather Service New Orleans LA 1238 PM CDT Sat May 17 2025 ...New AVIATION... .SHORT TERM... (Today through Sunday) Issued at 245 AM CDT Sat May 17 2025 Upper ridging over the Gulf, with troughing over Wisconsin and Baja California. At the surface, Bermuda high extends westward across much of the Gulf. Low pressure over Michigan had a cold front southwestward to Texas. Locally, it's a warm and steamy night, with temperatures between 75 and 80 and dew points mainly in the middle 70s. Shortwaves moving over the ridge will mainly keep precipitation north of the area through Sunday afternoon. Can'te entirely rule out a few showers or storms over southwest Mississippi this afternoon, but that'd be about it. Yesterday's high temperatures look to be a pretty good starting point for high temperatures the next couple days. That would be upper 80s to lower 90s for most of the area, and a few degrees cooler on the Mississippi coast, where the sea breeze may cap off heating before everywhere else. Short of having a thunderstorm, the numeric guidance for overnight lows looks several degrees too cool tonight, with mid 70s more likely than lower 70s. && .LONG TERM... (Sunday night through Friday) Issued at 245 AM CDT Sat May 17 2025 While ridging continues over the southern Gulf for most or all of next week, a strong trough moving through the Middle Mississippi River Valley into the Great Lakes will push a cold front into the area, and possibly through the area, at midweek. Medium range guidance coming into agreement that the only real significant chance of precipitation will be Tuesday night. Current NBM numbers would have a chance of precipitation both Tuesday night and Wednesday, but expect that later runs will back off on the Wednesday PoPs. Well above normal temperatures will continue until the frontal passage with highs upper 80s and lower 90s, and lows in the mid 70s. By Thursday and Friday mornings, morning lows likely to be at least 10 degrees cooler for much of the area, with some lows across northern portions in the 50s. Highs at the end of next week could range from upper 70s to mid 80s. We'll hold onto the NBM numbers for now. && .AVIATION... (18Z TAFS) Issued at 1235 PM CDT Sat May 17 2025 A scattered cumulus field ranging from 2500 to 3500 feet will remain in place through 00z. After 00z, skies will turn clear allowing for continued VFR conditions. Another inversion will develop after 06z, and this will result in another round of low stratus impacting all of the terminals between 06z and 15z. Most terminals will see ceilings remain above 1000 feet, but MCB, HDC, and BTR have a decent probability of seeing ceilings fall into IFR range of around 800 feet for a few hours around daybreak tomorrow. As seen the past few days, the stratus deck will break up and lift after 15z as temperatures warm and VFR conditions are expected at all of the terminals by the end of the forecast period. PG && .AVIATION... (12Z TAFS) Issued at 626 AM CDT Sat May 17 2025 Terminals are a mix of MVFR ceilings and VFR conditions at forecast issuance time. Expect cloud bases to lift above FL030 by mid to late morning, with VFR conditions for the remainder of the daylight hours. MVFR ceilings will redevelop by late evening at several terminals, continuing through mid-morning Sunday. There's a non-zero threat of convection this afternoon at KMCB, but much too low to carry in the terminals. && .MARINE... Issued at 245 AM CDT Sat May 17 2025 Can't entirely rule out winds briefly reaching or exceeding 15 knots at times, mainly over the western waters. Overall, any impacts to marine operations should be rather limited, if they occur at all. && .PRELIMINARY POINT TEMPS/POPS... MCB 71 91 72 91 / 10 0 0 0 BTR 74 92 75 92 / 0 0 0 0 ASD 73 90 73 89 / 0 0 0 0 MSY 75 90 76 90 / 0 0 0 0 GPT 73 85 74 86 / 0 0 0 0 PQL 71 87 72 87 / 0 0 0 0 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$ SHORT TERM...RW LONG TERM....RW AVIATION...PG MARINE...RW ####018004176#### FXUS63 KARX 171738 AFDARX Area Forecast Discussion National Weather Service La Crosse WI 1238 PM CDT Sat May 17 2025 .KEY MESSAGES... - Scattered showers (mainly northern WI) today with a dry, mostly sunny end to the weekend. Cool. - Rain returns for the start of the new work week with the highest chances on Tue, mostly along and south of I-90. && .DISCUSSION... Issued at 135 AM CDT Sat May 17 2025 - WEEKEND: scattered showers north, cloudy and much cooler today. Drier, not as windy, mostly sunny for Sunday. Upper level trough/closed low currently churning over northern WI early this morning, serving as the main focusing mechanism for scattered showers that are sweeping eastward across the local area. The low will make steady progress east today, moving over the eastern Great Lakes by 00z this evening. The bits of shortwave energy, cyclonic flow aloft and decent 1000:850 mb lapse rates will continue the showery conditions, mostly for northern WI, into the afternoon. Some suggestions of very weak instability in RAP/HRRR soundings, but not enough to warrant thunder inclusion into the forecast. While not nearly as windy as Friday, still a bit blustery as the sfc pressure gradient doesn't look to slacken until this evening when shortwave upper level ridging builds in. Sunday shaping up to be relatively cool, but with light winds and some sunshine (and no rain), a fairly nice end to the weekend. - START OF THE NEW WORK WEEK: rain chances return with Tue harboring the higher chances. Greatest threat/amounts currently favored mostly along/south of I-90. A longwave upper level trough remains set to move east from the west coast today, sliding over the mid mississippi river valley by Tue. While a bit of shortwave energy will rotate around the trough on Monday, the bulk of its influence will be west of the local area. It's a secondary shortwave dropping in from the PAC NW, then lifting northeast and rotating around a weak 500 mb low Tue, that promises widespread rains for portions of the region. At the sfc, the system's low is progged to stay well south of the forecast area, holding across northern MO-central IL. Low level moisture will push north/west to feed the system's deformation region with ample forcing via the shortwave, left exit region of a 300 mb jet, along with sloping Fgen response, to produce widespread rain. NAEFS and EC PW anomalies are close to +2 while EFIs run around 0.7 with a non- zero SoT. NAM/GFS upwards of 150% or normal for PWs. Where that deformation region sets up isn't quite clear though, with some of the EPS members bringing it up to the I-90 corridor, others holding it over IA. The bulk of the GEFS favors a more southern solution - but still brings rain up to I-90. What the models do agree upon is for the bulk of the rain to fall Tue. How much rain falls is also a question mark. Favorable west-east running orientation of the deformation region would favor time/residence enhancement of potential amounts. Large spread in both the GEFS and EPS 25-75% for amounts - ranging from less than 1/10" on the low end to 1+" on the higher end. Much of those differences are due to uncertainties in placement. Will continue to run with model blend for rain chances. Expect refinement to the northern extent of those chances, along with potential amounts, as we move into Monday. && .AVIATION /18Z TAFS THROUGH 18Z SUNDAY/... Issued at 1233 PM CDT Sat May 17 2025 Ongoing MVFR stratocumulus will continue to dominate concerns over the next TAF period. Expect ceilings, some of which remain under 2 kft, to slowly raise into the 2-3 kft range. Coverage should then slowly reduce southwest to northeast with most sites becoming VFR as ceilings scatter out Sunday morning. Otherwise, expect winds mainly out of the northwest. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ DISCUSSION...Boyne AVIATION...Ferguson