####018009547#### FXUS63 KLSX 160430 AFDLSX Area Forecast Discussion...Updated Aviation National Weather Service Saint Louis MO 1130 PM CDT Thu May 15 2025 .KEY MESSAGES... - There remains a very conditional threat of a couple of severe thunderstorms this evening across southeast Missouri and southwest Illinois. Large hail is the primary threat. - More widespread severe thunderstorms are likely Friday afternoon and early evening with all hazards, including very large hail (2.75+"), damaging winds, and a low chance of a strong tornado. The greatest severe risk is along/south of I-44 in MO and I-70 in IL. && .SHORT TERM... (Through Late Friday Afternoon) Issued at 221 PM CDT Thu May 15 2025 The Pacific cold front continues its eastward march across the CWA early this afternoon. As of 1900 UTC, it was located just west of a KVIH>>KPPQ line. The boundary is most evident looking at dewpoint values, as there is very little wind shift and not much of a temperature gradient associated with this front. The limiting factors discussed the past few days are all in play, with fairly strong capping evident between 800 and 900 hPa on ACARS soundings. Temperatures however toward the top of the inversion aloft are beginning to cool from west to east, so the strength of the cap should be weakening over the next few hours. The bigger problem from a convective initiation standpoint is forcing. Surface convergence along the boundary in our neck of the woods is nearly non existent, with maybe 20-40 degrees of veer as you travel from east to west across the boundary. The main thrust for mid/upper level forcing for ascent is also well to the north of the area. There is some convection across northern Arkansas and far southeast Missouri where surface convergence along the boundary is a bit stronger. Perhaps this is associated by a weak, but subtle midlevel impulse as well but neither short-term guidance nor water vapor imagery is really picking up on much of anything. The trajectory of these storms however should keep them southeast of our CWA. Some CAMs have suggested a brief isolated supercell or two out ahead of this area in southwest/south central Illinois between ~23 and 02Z. Maybe this is due to a subtle midlevel impulse and some cooling advecting in aloft. This is a long way of saying that any severe threat this evening remains highly conditional. The threat is also still very confined both temporally and spatially as detailed above. The Pacific cold front finishes moving through the area around 0300 or 0400 UTC, with dry weather favored for the remainder of the night. Cannot totally rule out a stray shower or weak thunderstorm overnight in far southeast Missouri, but chances appear to be at or below 10%. Confidence has continued to increase with respect to convective trends on Friday ahead of a stronger cold front that will move through the CWA. Southerly winds should increase quickly Friday morning, allowing for warmer and unstable air to surge back northward. There remains some degree of uncertainty on exactly how far north the richer dewpoints (and ergo, instability) advects by Friday afternoon, but it appears to be a slam dunk for southeast Missouri and southwest Illinois. Parts of east-central Missouri and western Illinois are more on the northwestern edge of where convection is likely to develop or where left moving supercells (after splits) may move into. The convective mode should be predominantly supercells, given a strong orthogonal component of the deep-layer shear vector to the orientation of the cold front. Hodographs show either straight hodographs or veer-back-veer profiles, both of which tend to favor at least some splitting of supercells. Left movers are typically shorter lived and almost exclusively a large hail threat while right movers are both hail and tornadic threats. Because of these splits, there also may be some mergers. These can be destructive or constructive in nature, but these mergers may also lead to some small bowing segments. This is where damaging winds would be most favored, as the current thinking is that any formation of a well-defined QLCS will not occur until after it exits the CWA. Overall, the main concerns continue to be on the potential for very large hail (2.75+") given supercells as a primary convective mode and very large CAPE within the -10 to -30C layer/hail growth zone. Any long-tracked supercell would have the capability of producing a swath of very large hail as well. There certainly is tornado potential, especially with more southern extent. Low-level shear/helicity increases as you go more into southeast Missouri and southwest Illinois. Storms will also not exit this area until closer to 23-0Z, which means some increase potentially in low-level cyclonic curvature of hodographs as the nocturnal low-level jet begins to increase. In terms of timing, there is more confidence on the end of the window for severe thunderstorms than the beginning. Storms should exit the area roughly between 23 and 0Z, but the onset could be as early as ~17Z or as late as ~20Z. The large difference on the front end is simply due to differences in exactly when convective initialization occurs tomorrow. Gosselin && .LONG TERM... (Friday Night through Next Thursday) Issued at 221 PM CDT Thu May 15 2025 (Friday Night - Saturday Night) After the passage of the cold front early Friday evening, a brief period of cooler and drier weather is likely to start off the weekend. Temperature trends with respect to Saturday continue to cool as guidance has trended more toward the cooler GFS/GEFS solution of the past couple of days. Highs on Saturday are forecast to be mainly in the mid to upper 70s, or right around normal for this time of year. Lows each night are expected to drop back into the 50s, which would also be near seasonal normals. (Sunday - Next Thursday) A return to a more active pattern remains in the offing late this weekend and into early next week. Not much has changed over the past couple of days, with an MCS expected both Sunday night and Monday night along/north of a retreating warm front. This boundary should progress northward in time, which means it is unlikely that the subsequent nocturnal MCS moves over the same region each night. Trying to pinpoint where each of these MCSs will track this far out is a fool's errand, but it does appear likely that widespread rainfall will accompany at least portions of the CWA with each round, the question is exactly where. Heavy rainfall (and possible flash flooding) could become more of a concern if Monday night's round tracks over the same areas as Sunday night's, but as all spelled out above, that does not seem likely at this point in time. Total precipitation probabilities for 2+" on the latest LREF peak out at about 40-50%, but drops to less than 10% for 4+". While April was very wet, soil moisture has largely reset back closer to normal levels due to mostly near or slightly below normal rainfall so far during the month of May. In fact, a good portion of northeast Missouri and west-central Illinois has been drier than normal and can really use 2-3" of rainfall. There also remains quite a bit of uncertainty with how Tuesday/Tuesday night will evolve as clusters of the 500-hPa height pattern diverge quite a bit with respect to the timing, track, and strength of the mid/upper level low coming out of the desert southwest. There may be a conditional threat for severe weather, but this will likely be dependent upon availability of sufficient instability. Given that an MCS is expected Monday night, ongoing showers/thunderstorms and cloud debris could really help limit daytime instability on Tuesday. While the exact timing is still unclear, ensemble guidance is in good agreement at a pretty significant pattern change for mid/late next week. A slow-moving mid/upper level closed low is likely going to be to our northeast, with well-below normal temperatures advecting in behind it. Both the EPS/GEFS show strong 850-hPa temperature anomalies (-5 to -8C). That is notable for late spring/almost early summer. Highs in the 60s to near 70 degrees are likely with lows dropping into the 40s to low 50s. Gosselin && .AVIATION... (For the 06z TAFs through 06z Friday Night) Issued at 1128 PM CDT Thu May 15 2025 Mainly dry and VFR conditions are expected through late morning and Friday afternoon when thunderstorms will develop across parts of central and eastern Missouri into southwest Illinois. Have included PROB30 groups from 16-19Z at COU/JEF and from 20-23Z at STL/SUS/CPS. Any of the thunderstorms will have the potential to produce MVFR or IFR ceilings and visibilities and the storms over STL/SUS/CPS on Friday afternoon may produce hail and wind gusts over 35 knots. Wind gusts outside of thunderstorms will diminish this evening only to increase again into the 20 to 30 knot range. Winds will turn out of the west and decrease on Friday evening. Britt && .LSX WATCHES/WARNINGS/ADVISORIES... MO...None. IL...None. && $$ WFO LSX ####018007624#### FXUS65 KRIW 160431 AFDRIW Area Forecast Discussion National Weather Service Riverton WY 1031 PM MDT Thu May 15 2025 .KEY MESSAGES... - A few lingering showers and thunderstorms this evening with activity quieting down by the early morning hours Friday. - Somewhat warmer Friday and Saturday with less coverage of showers and thunderstorms. - A Pacific weather system will bring a 50 to 60% chance of widespread rain and mountain snow from Sunday through Monday. && .UPDATE... Issued at 1224 PM MDT Thu May 15 2025 As of 1200L, the radar remains fairly quiet with only some light showers across western WY. Scattered showers have been steadily increasing in coverage across most areas west of the Divide and across northern WY over the last hour, and these are expected to continue to increase in coverage across the rest of the region through the early afternoon. Precipitation totals are much lower than yesterday, with likely only a few hundredths rather than tenths of precipitation out of the heavier showers. Thunderstorms will be much more isolated today as well, at only 10 to 20% coverage/probability. Though gusty winds and small hail are a possibility with any stronger storms, but those stronger storms are much less likely than in previous days (5 to 10% chance). Friday will see even less coverage of showers and storms with best chances (20 to 30% chance of showers) across the northwest. && .DISCUSSION... Issued at 326 AM MDT Thu May 15 2025 We have had some changes over the past few days. Storm movement was originally south to north on Tuesday, more westerly yesterday, and now we have transitioned to a northwest flow pattern. But one thing has remained constant, the chances of showers during the wettest time of the year across the Cowboy State. And this will continue through much of the next 7 days, although at varying coverages and intensities. The culprit for today's precipitation is a shortwave moving in from the northwest. We already have a few showers out there this morning, and these will increase in coverage as we head into the afternoon. And some of these showers could come with thunder, commonly known as thunderstorms. We do have some decent CAPE this afternoon, topping out around 500 J/Kg, although the lifted indices are not the best I've seen, generally around minus 1. So, I would put the chance of a thunderstorm at any location around 1 out of 4, with a greater chance of showers. And like previous days, the best chance of showers will be in northern Wyoming, with tapering chances further south. Precipitable waters are not terribly high though, generally topping at around 0.40 inches. And, with the storms moving at a decent clip, the threat of flooding looks small. So, the main threat would be gusty wind. I could also see some small hail, given the low wet bulb zero levels and cool temperatures, averaging around 10 degrees below normal. Wind will also be a concern today. The main area of concern looks to be northern Johnson County and the northern Big Horn Basin, with the favored northwest flow pattern behind the shortwave. Low level wind does not look sufficient for widespread high wind though, with 700 millibar wind topping out at around 40 knots when I would like to see 50 knots. Ensembles are giving around a 2 in 3 chance of gusts past 40 mph though, especially at Buffalo. So, it looks like a toupee alert day for many locations. Most showers should end by late this evening. And, there will be some snow in the mountains, with 700 millibar temperatures between minus 1 and minus 3, putting snow levels between 7000 and 8000 feet. Impacts would be minimal since the strong May sun should melt snow off of the roads. Shortwave ridging then moves across the state on Friday. This should cap the atmosphere a bit more and allow for somewhat warmer temperatures. We will still see some showers, but coverage will be less with most locations likely staying dry most of the time. Again, (noticing a pattern here), the best coverage will be across the north with southern Wyoming mainly dry. Saturday looks like the warmest day of the period as flow turns southwesterly ahead of the next weather system. The deepest moisture will stay west of the area on this day, but enough will move eastward and there will be a few showers and thunderstorms late in the day and in the evening. But, this day again looks like most areas will be dry most of the time so if you want do to something this weekend, Saturday definitely looks like the best day to do it. Then on Sunday into Monday, a big atmospheric bowling ball, AKA an upper level low, then moves into the Rockies and brings another period of wet weather. These lows are notoriously fickle with movement so details about timing of precipitation and amounts are still very much in flux. We do know a few things though. One, we have the concern of mountain snow, and potentially a decent amount of it. Models are indicating 700 millibar temperatures may fall as low as minus 3 in portions of the area, which could drop snow levels as low as 7000 feet on Monday. Probabilistic model guidance gives around a 1 in 2 chance of greater than a foot of snow from Sunday morning through Tuesday morning above 9000 feet across portions of the mountains. This is especially so in the ranges East of the Divide, where there would be some wrap around moisture and upslope on Monday. Not a certainly by any means, but something we have to watch. This could be a wet system, with a greater than 2 in 3 chance of over a half an inch or rain across the northern two thirds of the area through the period with favored northeasterly upslope locations having a greater than 1 in 2 chance of at least an inch of precipitation through 6 am on Tuesday. As a result, we will also have to watch for rising rivers. Melting snowpack would not be a concern though, given the cool temperatures though. Things get more muddled past Monday, as there are different solutions in regards to how fast the low will move away to the east. Most guidance shows ridging building behind the system, bringing drier and warmer weather, but when this will occur is still uncertain. && .AVIATION /06Z TAFS THROUGH 06Z SATURDAY/... Issued at 1030 PM MDT Thu May 15 2025 VFR conditions expected through the overnight hours. Any precipitation should be east and south of RIW/CPR to start the period, carrying only VCSH at CPR. Otherwise, broken low to mid level ceilings at all locations with light winds less than 10kts into the Friday morning hours. Ceilings will lift or scatter out with daytime heating and mixing after around 18-19Z as winds increase at BPI/PNA/RKS and strongest at CPR up to 25kts. A weaker and less scattered round of rain showers will only affect JAC/COD between 19/20-01/02Z with conditions likely to remain VFR (>60%). Otherwise, improved conditions in the wake of these rain showers lifting and scattering out as well after the end of the period and overnight into Saturday morning. Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for the latest information on smoke, icing, and turbulence forecasts. && .RIW WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Hensley DISCUSSION...Hattings AVIATION...Lowe ####018006886#### FXUS63 KDTX 160432 AFDDTX Area Forecast Discussion National Weather Service Detroit/Pontiac MI 1232 AM EDT Fri May 16 2025 .KEY MESSAGES... - Scattered severe thundestorms expected 10pm and 3am tonight. Large hail and damaging winds are the main threats, with a low chance of a few tornadoes. - Warm again on Friday with another round of showers and thunderstorms developing late Friday evening/Friday night. Some of these storms will also be strong to marginally severe. - Cooler conditions this weekend, with westerly wind gusts 30-40 mph on Saturday. && .AVIATION... Squall line producing very strong winds, large hail, isolated tornados, and persist downpours continues to work from west to east across the terminals tonight. Gusts in excess of 60 knots and at least one confirmed tornado have been reported upstream with this system. Trends continue to favor MVFR visibility reductions in the main rain band, with brief IFR reductions noted at MBS and FNT. Timing the exit is the main forecast concern for the next TAF cycle as the lingering back-edge will be slower to depart from DTW and DET near the very beginning of the TAF window. The line should fully clear east of all sites by 07Z. Post-frontal VFR conditions move in early Friday and throughout the day. Surface flow weakens, backing from southwest to southeast during the afternoon. Additional showers and storms possible late Friday evening. For DTW/D21 Convection... A decaying line of strong to severe thunderstorms crosses DTW during the 05-06Z time window. THRESHOLD PROBABILITIES... * Medium for ceiling 5000 feet or less toward midnight through sunrise the low through Friday. * High for thunderstorms tonight, mainly 05-06Z Friday, then low confidence after 00Z Saturday. && .PREV DISCUSSION... Issued at 307 PM EDT Thu May 15 2025 DISCUSSION... Moderate instability has built up across southeast Michigan with MLcapes aoa 1500 J/kg with sbcapes 2000-3000 J/kg as of 18z. None- the-less, just a modest CU field around as warm/dry mid levels cap activity for now. Severe thunderstorm chances will begin to increase this evening with arrival of the height falls and increasing wind fields, but bulk of thunderstorm activity looks to be impacting southeast Michigan around midnight. With the southeast winds, a stabilizing marine influence off of Lake Erie/Lake St. Clair looks to be coming into play, but an enhanced low level temperature/instability gradient will set up across the western half of the CWA (along/west of US-23). These locations stand the best chance of activity remaining surface based, and thus the greatest potential for damaging wind gusts with a chance of tornadoes as 0-1 KM bulk shear resides in the 25 to 30 knot range. With increasing southwest low level jet (50+ knots) and steep mid level lapses, large hail will be a concern as well, as cape (1500+ J/kg) is maximized around the freezing level to -20 C. Progressive nature of activity will limit flood threat, but urban areas (Wayne county) are not completely out of the woods, as strong to severe thunderstorms could drop a quick 1.5-2 inches in an hour in localized spots, as PW values peak around 1.75 inches. Majority of hi-res solutions all generally indicating a broken to near solid line of showers/thunderstorms rolling through, ending 2-4 AM. With the large 500 MB low center still back across the Western Great Lakes on Friday, deep southwest flow will promote another warm day, as 850 MB temps around 15 C will be supportive of high temperatures in the low to mid 80s. A spoke of energy/shortwave looks to be rotating around and tracking through southeast Michigan around midnight once again. Confidence is high in another round of showers and thunderstorms developing late Friday evening/night as the healthy cold front tracks through. Although instability parameters are less than this evening, wind fields/bulk shear and capes in 1000-2000 J/kg range seem supportive of at least a marginal risk of severe storms. Cooler and breezy on Saturday, as surface low (992-994 MB) tracks through the northern Great Lakes. Pretty good cold advection with 850 MB temps lowering into the mid single numbers. Steepening low level lapse rates during the day generates some modest cape, which may touch of isolated-scattered showers. Otherwise, local probabilistic guidance suggests wind gusts of 30-40 MPH during the day. Weak shortwave riding for Sunday, but there is already another shortwave/re-enforcing shot of cold air to track through the Great Lakes region for Sunday night. Dry air and northwest confluent flow looks to keep us dry to start the work week. Another large low pressure system to develop over the Central Plains, but still uncertainty with the magnitude and areal extent during the mid week period, which will impact the timing of showers returning to southeast Michigan. MARINE... Light E/SE flow continues across the region this afternoon-evening though funneling down the Saginaw Bay has allowed for local enhancement towards 15kts. A warm front tied to strong northern Plains low pressure is currently lifting out of the Ohio Valley towards the Great Lakes this afternoon. A line of strong/severe thunderstorms is expected to develop over the western Great Lakes and push through our area late evening-early tonight (~10p-3a). All hazards (strong winds, hail, waterspouts) are in play though wind gusts greater than 40kts and hail above a half inch are the main threats. Southerly winds up to 15-20kts develop post front for Friday as the low tracks over Lake Superior. This system then sweeps a cold front through the central Great Lakes late Friday evening- early Saturday night generating another line of showers and thunderstorms- a few of which could be severe (wind and hail hazards). Moderate west-southwest winds follow Saturday with the strongest winds (20-30kts) expected over the southern half of the region where the gradient is strongest. Small craft advisories are likely needed for most if not all nearshore waters as a result. Low fully departs Sunday shifting winds to the northwest. Gusts peak near 20kts during the day before weakening overnight as weak high pressure slides overhead. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...None. Lake St Clair...None. Michigan waters of Lake Erie...None. && $$ AVIATION.....KGK DISCUSSION...SF MARINE.......KDK You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit. ####018005186#### FXUS66 KPQR 160434 AAA AFDPQR Area Forecast Discussion...UPDATED National Weather Service Portland OR 933 PM PDT Thu May 15 2025 ...Updated aviation discussion... .SYNOPSIS...A progressive weather pattern will bring periods of light rain through the weekend, and possibly into early next week. Expect temperatures to remain slightly below average during this period. Light, steady rain expected as a weak front moves across the area today. Rain showers increase late Friday night through Saturday, along with a 10-20% chance of thunderstorms Sat afternoon. Lingering showers into Sunday, though most areas likely drier. Temperatures trending warmer toward the end of next week. && .DISCUSSION...Tonight through Thursday...Radar imagery shows light rain spreading across the area this afternoon as a weak front pushes onshore. Expect the cool, cloudy and damp conditions to persist through this evening. Onshore flow will maintain light scattered rain showers overnight into Friday, with the highest chances of rain persisting along the northern coast and coast range through Friday. Total rainfall amounts are generally expected around a tenth of an inch or less, except 0.20-0.40 inch north of Astoria, including the Willapa Hills. High temperatures warm into the mid-60s inland, upper 50s along the coast, on Friday, potentially warmer across southern portions of the area (e.g. Lane County) where more sunshine is possible as clouds scatter out. The active pattern continues late Friday into Saturday as an upper level jet over the north Pacific moves towards the Oregon coast. An initial shortwave trough slides across western Oregon early Saturday morning, initiating widespread rain showers. Northwest flow aloft is maintained as the stronger system drops southward along the British Columbia coast, digging into the Pacific Northwest. This will also bring a slight chance (10-20%) of thunderstorms to the area for Saturday afternoon/evening. Persistent showers will likely produce a bit more substantial rainfall amounts, including a 30-50% chance of exceeding 0.25 inch through Saturday night across much of the forecast area. Showers will likely persist along the higher terrain, including the Cascade foothills, where amounts closer to 0.50-1.00 inch of total (48-hr) rainfall are possible. Most areas should expect conditions trending drier on Sunday, with more sun breaks through the clouds by the afternoon. Temperatures still remain on the cooler side with highs reaching the lower to mid- 60s inland. Models and their ensembles are coming into better agreement that a weak front brings another round of light rain across the region on Monday. Cluster analysis also showing more zonal flow likely on Tuesday, keeping the door open for some light showers. But still, uncertainty remains into the middle of next week as about 60% of the clusters show some type of weak ridging. Still, the NBM suggest temperatures are likely to trend closer to normal. /DH && .AVIATION...Radar and satellite imagery as of 04z Fri depicts the latest frontal system moving east of the Cascades with widespread rain now transitioning into post-frontal showers. Shower activity will gradually decrease tonight, with most terminals becoming dry on Friday. An exception would be the north Oregon coast (KAST), where light showers are forecast to persist throughout the day with predominately MVFR CIGs. Along the central Oregon coast and Willamette Valley, expect mainly low-end VFR CIGs with intermittent MVFR CIGs (25-45% chance). Friday evening, another front will return rain and more widespread MVFR CIGs along the coast. Expect southerly to southwesterly winds under 10 kt across all terminals through the TAF period. PDX AND APPROACHES...Low-end VFR CIGs with intermittent MVFR CIGs through Friday morning (25-45% chance). After 21z Fri, expect predominately VFR CIGs. Southerly winds around 5 kt or less. -Alviz && .MARINE...Seas of 5-7 ft at 10 seconds will continue to slowly subside to 4-6 ft by early Friday morning. Northwest winds of less than 10 kt will back out of the southwest to south through tonight, increasing to 10-15 kt on Friday as a reinvigorated northwest swell arrives ahead of a frontal system. South to southwest flow ahead of the front will veer back out of the northwest in its wake, with a 25- 45% chance of gale-force gusts beyond 30 NM on Saturday, decreasing to 5-20% on Sunday. 70-90% agreement in at least Small Craft Craft winds during that time. Afterwards the next disturbance arrives Monday, marking a return to southerly winds around 10-15 kts. -Picard/JLiu && .PQR WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. PZ...None. && $$ www.weather.gov/portland Interact with us via social media: www.facebook.com/NWSPortland x.com/NWSPortland ####018006723#### FXUS62 KCHS 160434 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 1234 AM EDT Fri May 16 2025 .SYNOPSIS... Broad high pressure will remain across the area into the weekend. A weak cold front could approach the region this weekend with high pressure prevailing thereafter. A much stronger && .NEAR TERM /UNTIL 6 AM THIS MORNING/... Late this evening: Overall, a very quiet and early summer-like overnight period is expected. Coming off an afternoon with highs in the low 90s and with persistent southwest flow driven by a nearby inland trough, it will be a very mild night. Lows are forecast to only dip into the upper 60s for inland areas while the coastal corridor lingers in the low 70s. && .SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY/... Friday: The hottest day of the year so far seems likely across the region as strong upper ridging holds across the Southeast States. H8 temperatures are forecast to rise to 17-19C with low- level thicknesses peaking 1420-1425 m during peak heating. This coupled with little in the way of significant cloud cover and a downslope flow aloft should allow highs to reach into the lower-mid 90s just above everywhere except along the immediate coast where a late afternoon resultant sea breeze will take shape. Record highs at both the Charleston and Savannah Intl Airports could be challenged. The record in Downtown Charleston/Waterfront Park looks safe for now given where the resultant sea breeze is expected to set up, but even a slight delay in its development will have implications for Downtown Charleston. Modified forecast soundings show the atmosphere remaining strongly capped through the day with no forcing aloft noted given the orientation of the upper ridge. A rain-free forecast was maintained. Dewpoints are now forecast to mix out a bit more than previously expected with value dropping into the upper 60s/lower 70s. The resulting heat indices peak in the 98-101 range and well below the 108 Heat Advisory criteria. While this is a tad lower than previous forecasts, the baseline key message remains that extra precautions should be taken given its the first significant heat episode of the year. Note, the experimental Heat Risk level is solidly in the orange/risk level 2 category all but the beaches. It will be a warm overnight with lows dropping into the upper 60s/lower 70s, except mid 70s at the beaches and Downtown Charleston. Saturday: The upper ridge aloft will steadily weaken with the flow aloft becoming more zonal with time. A cold front will meander into South Carolina and Georgia during the day, but there is much uncertainty how far south the front will drift as it becomes increasingly parallel to the flow aloft. Some degree of convection will accompany the front as it moves into northern Georgia, the Upstate into western North Carolina Saturday morning, but guidance remains mixed on how much activity will take it this far south into southern South Carolina into Southeast Georgia during the late afternoon into the evening hours given the mean westerly flow ahead of the front. A number of the GEFS members are showing measurable rainfall over the area as the front settles south, but the 15/12z operational GFS still looks to have some convective feedback issues. For now, the 15/13z NBM is favored, but with slightly wetter guidance blended in to trend. This still yields gridded pops just below 20%, but these are certainly higher than the previous forecast cycle. Mentionable pops may eventually be needed if models trend wetter overall. It will remain hot and somewhat humid with highs warming into the lower-mid 90s away from the immediate coast. Lows will drop into the upper 60s/lower 70s with mid 70s at the beaches and Downtown Charleston. Sunday: The frontal remnants will linger nearby through the day as a sea breeze moves inland. There may be enough instability and convergence ahead of the sea breeze to generate a few showers/tstms, mainly inland from the coastal corridor. Slight chance pops were maintained. Highs will warm into the upper 80s/lower 90s away from the beaches. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... Upper ridging will mostly dominate aloft through Tuesday before the a large upper trough will impact the eastern CONUS by the middle part of next week, helping to push a stronger cold front across the Southeast States. The front will bring the next meaningful chance for showers and tstms. Temperatures will remain above average through Tuesday, then return closer to climatology Wednesday into Thursday. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... Today/ Friday: VFR/ no precipitation forecast. Light southwest winds through the early morning hours then slowly veering from the west after daybreak. By the afternoon, a sea breeze will begin to form along the SC/ GA coast and start to move inland. Winds at KJZI will back from the south/ southwest first followed by KCHS and KSAV. Tonight: VFR. Extended Aviation Outlook: The risk for showers/tstms will increase by the middle of next week. && .MARINE... Tonight: Sea breeze surges in the Charleston Harbor should end shortly after sunset. Otherwise, southwest winds 10-15 kt will prevail overnight for all waters with seas 2-4 ft. Friday through Tuesday: Southerly wind regime will prevail for much of the period. Another sea breeze surge looks like Friday along the land/sea interface and Charleston Harbor. Winds increase a bit more all areas for Saturday ahead of an approaching cold front. Winds may reach as high as 15-20 kt during this time. Otherwise, speeds will remain less than 15 kt, except higher near the sea breeze. Seas will generally remain 4 ft or less through the period. && .CLIMATE... Record High Temperatures: May 16: KCHS: 94/1941 KSAV: 95/1915 May 19: KSAV: 97/1996 May 20: KSAV: 96/2006 Record High Minimum Temperatures: May 16: KCHS: 71/2018 KSAV: 74/1915 May 17: KCHS: 74/1995 KCXM: 75/1998 KSAV: 74/1995 May 18: KCHS: 75/1995 KCXM: 77/1991 KSAV: 74/1899 May 19: KSAV: 74/1930 May 20: KCHS: 72/2022 KCXM: 76/2022 KSAV: 73/1896 May 21: KCHS: 74/2022 KSAV: 74/2017 && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM...BSH SHORT TERM... LONG TERM... AVIATION...BSH/Haines MARINE...