####018008306#### FXUS63 KGID 162339 AFDGID Area Forecast Discussion National Weather Service Hastings NE 639 PM CDT Fri May 16 2025 ...AVIATION UPDATE... .KEY MESSAGES... - Strong NW winds currently in place (gusting near 45-50 MPH at times) will linger through late afternoon...gradually diminishing this evening/overnight. Current isolated/scattered showers across northern areas will also diminish this evening, with dry conditions overnight. - Saturday still looking to be an overall pleasant day. Dry conditions are forecast, with lighter winds turning more easterly with time and highs in the 70s. - A more active pattern is expected Sunday through Tuesday, as a couple of upper level disturbances look to swing through the region. Thunderstorm chances return to the entire area, some of which may be strong to severe, especially Sun-Mon during the afternoon-evening hours. && .DISCUSSION... Issued at 411 PM CDT Fri May 16 2025 Currently... Upper air and satellite data show generally westerly flow aloft across the area...as we sit on the southern side of a larger area of low pressure making its way east across MN. The majority of the forecast area has been dry...but enough moisture has been wrapping around the backside of the main low to bring some isolated/scattered showers to northern locations. Not looking at any notable rain out of any of these showers unfortunately. At the surface, low pressure is also in place over MN...with continued gusty NW winds area-wide. Gusts through the day around 40-45 MPH have been fairly widespread...with a handful of sites up in the 50-55 MPH range at times, mainly across the northern half of the forecast area. Only airport so far to hit 'severe' criteria (58+) is Hastings, which hit exactly 58 MPH this afternoon. Plenty of cloud cover sinking south has also helped keep things cooler for some...here at mid afternoon temps range from the upper 50s at ODX to the upper 70s across portions of north central KS. This evening through Saturday... Spotty precipitation ongoing this afternoon is expected to diminish by early evening...with the forecast for tonight on through Saturday remaining dry. Models are in good agreement, showing by 12Z Saturday, the main upper level over MN has pushed further east into the Great Lakes region, while the next system of interest is making its way onto the West Coast. This will allow for broad upper level ridging to cross the area...with no notable systems crossing the area. At the surface...the current gusty winds are expected to gradually taper off with time this evening/tonight...as a ridge axis works its way into the area. Winds for most remain generally NWrly tonight...with winds then turning more easterly gradually with time through the day on Saturday. Compared the previous couple of days, Saturday's winds will feel nice...with speeds closer to sustained 15 MPH vs the 25-35 we are seeing today. Saturday highs look to be pleasant...topping out in the low-mid 70s. Sunday through Tuesday... Best precipitation chances for the 7-day period continue lie in this time frame, with a couple of disturbances looking to swing through the Plains. Saturday night into early Sunday morning, models show this next upper level low/trough digging SSE...stretching from the Pac NW into the Desert SW by 12Z Sunday. Some models showing the potential for light precipitation to start working its way in from the south early Sunday morning, stretched along the leading edge of better moisture advection...shifting further north through the first half of the day. Not a ton of confidence in how impactful this would be, if it happens, so chances remain in the 20-30 percent range for most through 18Z Sunday. Through the afternoon...focus will be turning to the approaching upper level shortwave disturbance, which will be swinging northeast out of the Four Corners region on through CO. At the surface, deepening low pressure will also be working its way ENE, ending up along the CO/KS border by early evening...exactly where the low is centered is still a bit uncertain. As a result, confidence in the exact location of the accompanying sfc warm front and dryline suffers...and their locations will be an important part in thunderstorm/severe weather potential. The entire forecast area is included in at least the SPC Day 3 Slight Risk...with the far SE portions included in the Enhanced Risk area. Models showing plenty of instability developing across the area, but again how much of that creeps north into our forecast area will be dependent on the location of those sfc features...and there is some question with warmer mid-level temps/capping and how long it holds things off. Threat for strong-severe storms may carry well into the overnight hours, shifting further north and east with time as the LLJ increases. All severe weather threats will be possible. The shortwave disturbance driving Sunday's chances is shown by models to deepen into a more organized area of low pressure as we get into Monday...and while storm chances linger through the day/evening, where that upper low ultimately sets up will be interesting. If it sets up far enough north/east...like some models have...precipitation and severe weather chances may largely be focused outside of our forecast area, driven by the next shortwave disturbance swinging around the southern edge of this newer low. Overall confidence in exact locations of the upper level features and sfc features (which may impacted by any boundary set down by Sunday's activity) is not high at this point. A more western location of that upper low would keep the severe weather threat around at least the eastern half of the forecast area...which remain outlooked in the SPC Day 4 15 percent area. Models show things in the upper levels becoming more phased together with time, but its not until Tuesday-Tuesday night that the whole system finally makes a better push through and out of the forecast area. Following forecast highs Sunday and Monday in the 70s-80s, highs on Tuesday are only in the 50s-60s as the system works its way through. Wednesday and Thursday... The forecast for much of the Wed-Thu time frame is dry in the wake of this early week system...but there is some uncertainty with how quickly activity does end Tuesday night, not out of the question there could be some lingering activity Wed morning. More northwesterly flow looks to set up across the region...with models showing the potential for another system to slide in Thursday evening-night. Current forecast highs for Wed are in the 60s, with 70s back for Thursday. && .AVIATION /00Z TAFS THROUGH 00Z SATURDAY/... Issued at 619 PM CDT Fri May 16 2025 For KGRI/KEAR Airports: Prevailing VFR conditions expected through the period with very strong winds expected to persist through around 17/03Z...and diminishing to near 10 KTS overnight. Expect the upper level low over Minnesota this evening to shift east into Wisconsin by midnight, with the strong winds in its wake gradually decoupling and shifting east over the same time period. The mid level clouds wrapping around this low should also exit the area, with CIGS already beginning to improve at KEAR with similar improvements expected at KGRI over the next couple of hours. As winds diminish late this evening...could see some modest LLWS for a few hours overnight, but with the focus further north and east of the terminals as the low exits the region, decided not to include any mention in the 17/00Z TAFs. Skies should then become mostly clear by early Saturday morning, with generally light northeasterly winds returning (with a few gusts of 15-18KTS) through the end of the TAF period. && .GID WATCHES/WARNINGS/ADVISORIES... NE...High Wind Warning until 8 PM CDT this evening for NEZ039>041- 046>049. KS...None. && $$ DISCUSSION...ADP AVIATION...Rossi ####018010379#### FXUS61 KAKQ 162340 AFDAKQ AREA FORECAST DISCUSSION National Weather Service Wakefield VA 740 PM EDT Fri May 16 2025 .SYNOPSIS... Strong to severe thunderstorms are possible through late this evening. Warm temperatures are again expected on Saturday with low-end chances for storms near the coast. High pressure briefly returns for Sunday and Monday. Temperatures cool down and conditions become unsettled into the middle of next week as an upper level low pressure system develops west of the area. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... As of 330 PM EDT Friday... Key Messages: - A round of strong to severe thunderstorms is possible between 4-9 PM across the entire area. The main threat with this is damaging wind gusts up to 70 mph, with a low-end threat for large hail and/or a brief tornado. - A second round of storms is possible after 2-3 AM tonight, which could pose a low-end threat for damaging wind gusts. However, this is highly uncertain and depends on the evolution of the initial round of storms. The flow aloft remains WSW late this morning as upper ridging slowly pushes to our east. A prominent upper low (stacked atop strong sfc low pressure) continues to spin over the Upper Midwest. Still no prominent surface features nearby, with a cold front still well to our NW and high pressure well offshore to our SE. Dry/very war, wx continues with temps around 90F and mid 60s-lower 70s dew pts, but am watching strong to severe tstms across SW Virginia. In addition, a few severe storms have formed near the MD/DE border that are exhibiting supercellular characteristics. The environment is characterized by steep low/mid-level lapse rates, strong instability (2000-3000 J/kg MLCAPE) and 40-50 kt effective shear (mainly speed shear as hodographs are mostly straight). Strong to severe storms may impact the MD Eastern Shore during the next couple of hours. Otherwise, we're watching the convection in western VA which is expected to reach the Piedmont by 4-5 PM. This is the main area of convection that we'll be watching for potential severe wx. A Severe Thunderstorm Watch has been issued for the entire area until 03z/11 PM to account for the threat. There are still uncertainties with respect to convective coverage later this aftn/this evening. But consensus (as well as upstream trends) show that at least a broken line of tstms will cross the CWA from west to east between 4 PM and 9 PM. This is also supported by the WoFS This solution is shown by most of the incoming 12z/16 CAMs. Given the environmental parameters mentioned above (which are much more favorable for severe wx than we typically see in the Mid- Atlantic), the main threat will be for severe wind gusts (potentially to 70 mph). Large hail will also be possible (have seen reports of 1.75" hail just to our north). Can't rule out a brief tornado as well, but a lack of directional shear will mitigate the tornado threat. There will likely be a break in the storms late this evening-early tonight before a second round of storms potentially approaches early Sat AM (after 2-3 AM). However, these will be weakening as they approach but will pose a low-end threat for damaging wind gusts. Also, if the first round comes through as advertised, this will act to stabilize the environment and thus further lessen the threat for additional severe wind early Sat AM. Have raised PoPs to ~50% through the evening to account for increased confidence in the first round of convection and will maintain chc PoPs later tonight. The Storm Prediction Center has a Slight Risk (Level 2 out of 5) for the entire area. Lows tonight should be very reminiscent of summer and range from the upper 60s to lower 70s. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/... As of 330 PM EDT Friday... Key Messages: - Very warm Saturday with a slight chance of thunderstorms across SE VA and NE NC. - Drying out later Saturday into Sunday behind a cold front. Another hot day is ahead for Saturday ahead of a cold front as morning convection should dissipate by 6-9 AM. High temperatures in the upper 80s to lower 90s are expected, with the warmest temps across the SE. The main change in the forecast for Saturday is the waning confidence in severe wx (and also convective initiation during the aftn) as winds become west and dew pts fall during the aftn (especially inland). Will keep 20% PoPs across SE VA/NE NC to account for additional tstm development between 2-8 PM. There will still likely be a highly conditional severe threat across the SE given strong sfc heating and still decent shear in place. Of course, confidence is low regarding any sort of convective initiation. Given this, SPC has maintained a Level 1 out of 5 (Marginal) severe weather risk near the coast. The main threat would again be damaging winds, with large hail also possible. With drier air filtering in behind the front Saturday night, expect cooler low temps in the lower to mid 60s. Still quite warm for Sunday/Monday as only modest cold advection occurs behind the front. Highs in the lower to mid 80s both days, warmest across the S and SE and coolest on the Eastern Shore. Overnight lows Sun night drop into the 50s inland and lower 60s closer to the coast. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... As of 330 PM EDT Friday... Key Messages: - Unsettled weather returns later Tuesday through Thursday. - Below average temperatures return by late next week and likely last into next weekend. Unsettled wx returns for the mid to late week period as an upper level low is progged to track from the Midwest to the east coast from Tuesday through Thursday, before slowly exiting to the NE by Friday/Friday night. While the specifics remain unclear with differences among the deterministic guidance, Tuesday night- Wednesday looks like the wettest period, with a drying trend expected by Thu as cooler air filters in from the NW. With the increased precipitation chances, temperatures trend cooler...and likely below seasonal norms...by Wednesday and Thursday. Below normal temperatures remain favored through the end of the week and looking ahead to Memorial Day weekend. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... As of 735 PM EDT Friday... Strong thunderstorms have pushed east of RIC/SBY/PHF this evening. May continue to see a period of gusty winds behind the convection during the next hour or so at SBY and PHF, then returning to a lighter SW flow. Weakening showers and storms impact ORF and ECG early in the period, which may bring a period of reduced vsbys and gusty winds. A complex of storms to our west and weaken as it approaches late tonight into early Saturday morning. This second round of convection may impact the area (especially RIC/SBY) between 07-12z. Will have VCSH for now given low confidence. Additional showers/storms will remain possible into early Saturday morning. Breezy on Sat with W-WSW winds of 10-15 kt with 20-25 kt gusts. Isolated showers and storms are possible near the coast Saturday afternoon, but PoPs are only ~20%. Outlook...Prevailing VFR conditions are expected over the weekend into early next week. && .MARINE... As of 400 PM EDT Friday... ey Messages... - Severe storms possible through this evening with wind gusts in excess of 50 kt possible. - SW winds gusting to 20 to 25 kt in the lower Chesapeake Bay/ York/James Rivers and Currituck Sound on Saturday. A small craft advisory is in effect. - More tranquil marine weather expected Sunday into early next week. SW winds mostly 10 kt or less across the waters this afternoon with a weak trough across the waters. The main concern through this evening will be the chances for severe thunderstorms and the potential for severe wind gusts. Currently one storm just north of Ocean City that will likely impact the far northern Coastal Waters near the MD/DE waters for the next few hours. However, latest high resolution forecast guidance suggests that strong to severe storms will impact the waters perhaps as early as 5 to 7 pm over the central Chesapeake Bay and 6 to 9 pm over the remainder of the waters. These storms have the potential for wind gusts in excess of 50 kt and large hail as they move through. Any storm threat should exit by 9 to 10 pm. The pressure gradient picks up over the waters somewhat on Saturday ahead of the cold front. These southwest winds will become rather gusty over land, however some of these 20kt gusts will likely impact the southern Chesapeake Bay, James/York Rivers and Currituck Sound. As such, have issued a small craft advisory for these areas on Saturday into Saturday evening. SW winds decrease early Saturday evening as the front pushes through. Behind the front, winds gradually turn west then northwest on Sunday. Low pressure then deepens over the Canadian Maritimes Sun night into Monday which should allow for NW winds to increase to around 15 kt across the waters. May need small craft advisories with this northerly surge but there is still some uncertainty. Winds gradually turn to the east by Tuesday as low pressure develops to the west of the area and a frontal boundary stays south of the region. && .HYDROLOGY... As of 300 PM EDT Thursday... Flood Warnings continue along the James River, at Richmond- Westham, and Richmond Locks have crested, but will remain in minor flood stage through Friday night. See water.noaa.gov for more site- specific information. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...Small Craft Advisory from 10 AM to 10 PM EDT Saturday for ANZ632-634-636>638. Small Craft Advisory from 10 AM to 7 PM EDT Saturday for ANZ633. && $$ SYNOPSIS...SW NEAR TERM...ERI SHORT TERM...ERI/SW LONG TERM...KMC/SW AVIATION...AC MARINE...MRD HYDROLOGY... ####018003686#### FXUS63 KFGF 162340 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 640 PM CDT Fri May 16 2025 .KEY MESSAGES... - Winds gusts of 50 mph are possible along and west of the Red River Valley this evening. A wind advisory is in effect through 1am. - Near freezing temperatures are possible in portions of northeastern North Dakota tonight and Saturday morning. A frost advisory is in effect tonight into Saturday morning. Additional freezing temperatures are possible Saturday night into Sunday morning. && .UPDATE... Issued at 640 PM CDT Fri May 16 2025 Rain continues on and off this evening with another tenth of an inch or so expected before rain ends for most Saturday afternoon. Frost still expected in the upper Devils Lake basin though poor radiational cooling between clouds and elevated winds will likely prevent frost from becoming widespread except in more sheltered areas. && .DISCUSSION... Issued at 342 PM CDT Fri May 16 2025 ...Synopsis... Widespread cloud cover remains in place this afternoon across much of the Northern Plains and Upper Midwest. A cut off H5 upper low is moving very slowly to the east, with scattered showers expected to continue intermittently through early this evening. Ridging begins to build into the Central Plains this weekend, with the axis being somewhat limited by short residence time ahead of another system. This will bring rain chances back into the area Monday into Tuesday. Weak ridging builds back into the area by mid week with additional rain chances returning Thursday into Friday. ...Wind Gusts up to 50 mph Today... Pressure rises and weak CAA will contribute to strong north winds through the remainder of the afternoon into the early evening. Sustained winds will continue to range from 20 to 25 mph with gusts up to 50 mph. Winds are expected to slowly diminish this evening as the upper low moves to the east. ...Near Freezing Temps Possible Tonight into Saturday Morning... Colder air continues to work into the area tonight into Saturday. Near freezing temperatures are possible, especially for the Devils Lake Basin and areas northward to the International Border. There remains some uncertainty regarding cloud cover, with most guidance keeping at least a scattered cloud deck over the area through much of the night. This will serve to inhibit temperatures from falling into the upper 20s, although isolated cooler spots may see a brief period of colder temps. The current expectation brings widespread low to mid 30s into the area. && .AVIATION /00Z TAFS THROUGH 00Z SUNDAY/... Issued at 640 PM CDT Fri May 16 2025 IFR to MVFR are widespread this evening and will remain such through the overnight before lifting as the low pressure driving these showers and low clouds shifts away from the area. Can generally expect improving ceilings after 18z for but wouldn't count anything sooner than that. Winds will take their sweet time to diminish with generally gusty 20+ knot winds through at least early tomorrow afternoon aside from BJI where the trees may bring relief a bit sooner towards 12z. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...Wind Advisory until 1 AM CDT Saturday for NDZ006>008-014>016- 024-026>030-038-039-049-052>054. Frost Advisory from 2 AM to 10 AM CDT Saturday for NDZ006>008- 014>016-054. MN...Wind Advisory until 1 AM CDT Saturday for MNZ001>004-007. && $$ UPDATE...TT DISCUSSION...Lynch AVIATION...TT ####018004982#### FXUS64 KAMA 162340 AFDAMA Area Forecast Discussion National Weather Service Amarillo TX 640 PM CDT Fri May 16 2025 ...New AVIATION... .KEY MESSAGES... Issued at 213 PM CDT Fri May 16 2025 - There is a very slight chance for a severe thunderstorm in the northeastern combined Panhandles tomorrow afternoon. - Temperatures will return to the upper-80s to low-90s across most of the Panhandles this weekend. - Breezy to windy conditions will be possible on Sunday and Monday. - Highly conditional storm chances in the far eastern Panhandles on Sunday. Potential for storms to become severe if they do form. && .SHORT TERM ... (This evening through Saturday night) Issued at 213 PM CDT Fri May 16 2025 A closed mid to upper low is currently over MN about to enter the Great Lakes Region as of this writing. This is the system expected to feed some severe weather for the Ohio River Valley later today. Now for the FA, the Panhandles are south of this system with quasi- zonal flow aloft. For the combined OK/TX Panhandles, fairly benign weather is expected today and mostly tomorrow with relatively calm winds. Afternoon highs tomorrow may be a few degrees warmer especially over the southeastern TX Panhandle into the mid to upper 80s. Under the southwest flow aloft tomorrow, some perturbations may try to spark a thunderstorm or two in the far northeastern combined Panhandles. Some CAMs are trying to pop a thunderstorm over or around Beaver County before moving northeast into KS and fall apart. Have added a slight chance PoP between 3PM and 7PM tomorrow afternoon mainly for Beaver County. If something can get going, storms may be high based but potentially severe. NAM has MLCAPE values well over 3000 J/Kg with bulk shear well over 30 kts. H7 theta-e does not look the greatest and confidence is not very high for storm development but will need to be watched. 36 && .LONG TERM ... (Sunday through next Thursday) Issued at 213 PM CDT Fri May 16 2025 By Sunday, much of the western CONUS will be under a broad mid to upper level trough. This trough will have the FA under southwest flow aloft and feed a surface trough. The surface trough is expected to bring dry and breezy conditions to the combined Panhandles. A dryline is expected to develop along the front edge of the surface trough. Where this dryline sets up is yet to be determined, but confidence is high that it will be east of the combined Panhandles. This will limit storm chances for the far eastern combined Panhandles. Depending on the progression of the dryline a 10 to 20 PoP may be needed to cover storms that develop in the area before east into western OK. For now PoPs remain less than 10 percent. Monday, as the surface low progesses east, a cold front will fill in behind and bring north winds. Breezy winds are expected Mon afternoon ahead of the front with breezy winds Tue behind the front. Some few ensemble members are hinting at showers behind the front in the northern combined Panhandles Mon night. The NBM seems to be heavily weighted by some outliers as the NBM50 has no QPF and the NBM75 has less coverage of QPF than the mean. Have left some slight chance PoPs in for now. Tuesday, behind the front, afternoon temperatures are expected to be in the 70s. Wednesday, conditions warm slightly into the upper 70s with light winds. It is not until Thu when temperatures bounce well into the 80s with potential 90s on Fri. 36 && .AVIATION... (00Z TAFS) Issued at 632 PM CDT Fri May 16 2025 VFR conditions are expected throughout the 00Z TAF period at all TAF sites. Winds will generally be out of the southwest at 5-15 kts with higher gusts at times with few to sct high clouds. && .PRELIMINARY POINT TEMPS/POPS... Amarillo TX 55 87 55 87 / 0 0 0 0 Beaver OK 49 85 52 93 / 0 20 10 0 Boise City OK 45 82 47 84 / 0 0 0 0 Borger TX 53 90 55 92 / 0 10 0 0 Boys Ranch TX 50 87 51 87 / 0 0 0 0 Canyon TX 53 87 52 87 / 0 0 0 0 Clarendon TX 57 88 57 90 / 0 10 0 0 Dalhart TX 46 83 46 84 / 0 0 0 0 Guymon OK 45 85 48 89 / 0 10 0 0 Hereford TX 53 87 51 87 / 0 0 0 0 Lipscomb TX 52 87 56 91 / 0 20 10 0 Pampa TX 55 88 57 89 / 0 10 0 0 Shamrock TX 56 88 58 91 / 0 10 10 10 Wellington TX 56 90 60 92 / 0 10 10 10 && .AMA WATCHES/WARNINGS/ADVISORIES... TX...None. OK...None. && $$ SHORT TERM...36 LONG TERM....36 AVIATION...29 ####018007891#### FXUS62 KFFC 162341 AFDFFC Area Forecast Discussion National Weather Service Peachtree City GA 741 PM EDT Fri May 16 2025 ...New 00Z Aviation Discussion... .SHORT TERM... (This evening through Saturday) Issued at 308 PM EDT Fri May 16 2025 Key Messages: - Temps in the upper 80s to low 90s (10-12 degrees above normal could lead to a record this afternoon for KATL. - Line of thunderstorms pushing through north Georgia, late tonight into tomorrow morning. (1AM-8AM for areas north of I-20). Discussion: Current stream of moisture coming from the Pacific ahead of the line tonight is leading to the low clouds this morning from the SW and the high level cirrus. Meanwhile the low pressure system that will bring in our line of showers and thunderstorms overnight is positioned over Minnesota with an attendant cold front through the mid MS valley. This low pressure system pushes eastward into the great lakes region with the front also pushing into Tennessee and northern Georgia and Alabama this evening into the overnight. Over our area SPC has outlined extreme northwest Georgia in a slight risk (level 2 of 5) with a marginal risk (level 1 of 5)pushing southward to the northern reaches of the metro. Taking a deeper dive into the parameters, MUCAPE values of 2500-3000J/kg, 40-55kts of 0-1km bulk shear and 0-1km SRH values of 200-300 m^2/s^2 are forecasted for northwest Georgia as the line pushes into northwest Georgia. These variables are conducive to the slight risk outlined with damaging wind gusts and a low risk for tornadoes. The tornado risk has gone from very low to low with this system with the main area to watch for being that far NW GA area. Would not be surprised to see a few spin up type tornadoes, but overall that damaging wind threat will be the highest. Timing for the system looks like 1-2AM to push into far NW Georgia before pushing southward and reaching the northern metro by 4-5AM before the front loses steam and stalls out. The main threat window will be from 1AM-8AM tomorrow. After the front pushes into the area late morning, expecting it to stall out over the area somewhere between the metro and a line from MAcon to Columbus where tomorrow could see some showers begin to form along the boundary. CAMs are a little less bullish on this and thus precip chances are closer to 20-30%. Tomorrow night could see the beginnings of another wave of precip moving into the area but most of that timing is pushing into Sunday and thus mentioned below. Hernandez && .LONG TERM... (Sunday morning through next Thursday) Issued at 308 PM EDT Fri May 16 2025 Key Messages: - Rain and a few thunderstorms possible on Sunday. Can't rule out an isolated severe storm or two. - Monitoring for storm potential in north Georgia on Monday. Again, can't rule out the possibility of seeing something severe. - Stronger front will roll through in the middle of next week. Will need to monitor this for some severe weather potential, but currently a bit too much uncertainty around timing, orientation, and some other parameters to solidly say severe will be possible. Forecast: Stalled surface frontal boundary will still be in place across the CWA Sunday morning as a quick hitting shortwave rotates through the longer-wave ridging building over the CWA between two troughs located over the eastern seaboard and western CONUS. This system looks as though it will cause enough surface mass response to generate some rain and possibly a few thunderstorms over the CWA on Sunday morning into Sunday afternoon, with best chances to the west/northwest where isentropic lift will be most aligned with the stalled surface boundary. Model soundings are limited in instability, especially given the potential for cloud cover, but given the shear that will be in place, there will be the possibility for an isolated severe thunderstorm to occur, with damaging wind gusts being the primary threat. These should quickly lose steam by sunset, though some showers and storms may linger into the overnight hours. Monday has started to get an interesting look to it from this forecaster's perspective. Another shortwave (in this case, noted as a piece of the upper level PV within the western trough that gets sheared off as a result of a stronger TPV digging in behind it) ejects into the Great Plains Sunday evening and causes a pretty robust baroclinic response with surface low and convection developing. Diving into some of the deterministic output shows that some of the guidance holds that convection together overnight as it rides the subtropical ridge and becomes a bit organized with potential cold pool. This convection then turns more south during the day on Monday as it rides within the NW flow, become a pretty classic setup for a honkin' line of storms to move through portions of the southeast. This will need to be monitored going forward for severe potential, given an ample parameter space will exist with plenty of shear and instability. Uncertainty is still a bit too high to highlight this as a severe area within SPC style outlooks, however, both around if it forms and exactly where it would eventually travel. By the middle of the week, set up aloft gets a bit more complex. The larger trough in the desert SW is progged to eject into the Great Plains and eventually into the eastern CONUS, but several complex interactions around this will dictate exactly where and when it ends up traveling. These interactions will have strong dependencies on convection (and more specifically, the latent heating produced by said convection) that I simply do not trust longer range global guidance to have a good handle on. Still, as some point the expectation is that a stronger cold front will push through the CWA, bringing an additional round of rainfall and the potential for some form of severe weather (insert "It's gonna be May" JT meme here). Only other thing to note will be the temperatures. While highs on Sunday may be a bit more muted thanks to the weak front and potential cloud cover and rain, they are still forecast several degrees above average in the mid 80s to low 90s. This only builds into Monday and Tuesday. Current forecasts are a few degrees below the record highs at several locations, so expect some heat. Lusk && .AVIATION... (00Z TAFS) Issued at 740 PM EDT Fri May 16 2025 A BKN VFR Deck is expected to remain in place into the overnight hours. A line of TSRA is expected to reach ATL after 10Z and clear out around 14Z. Winds will be on the west side at 5-10kts. After the line clears the area, there could be a few hours of low CIGS on the back side of the front, though obs below MVFR are not expected. //ATL Confidence...00Z Update... High on all elements. Vaughn && .PRELIMINARY POINT TEMPS/POPS... Athens 70 87 66 86 / 10 30 10 30 Atlanta 71 87 68 87 / 30 20 10 40 Blairsville 64 81 61 80 / 60 20 10 40 Cartersville 68 87 65 86 / 50 20 10 50 Columbus 70 90 68 90 / 0 20 10 40 Gainesville 70 85 67 85 / 30 20 10 40 Macon 69 90 68 90 / 0 20 10 30 Rome 68 87 65 85 / 60 10 20 50 Peachtree City 70 87 65 87 / 20 30 10 40 Vidalia 69 92 71 92 / 0 10 10 20 && .FFC WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Hernandez LONG TERM....Lusk AVIATION...Vaughn ####018005448#### FXUS65 KCYS 162342 AFDCYS Area Forecast Discussion National Weather Service Cheyenne WY 542 PM MDT Fri May 16 2025 .KEY MESSAGES... - Seasonable temperatures into this weekend with isolated thunderstorms returning on Saturday. - Active weather pattern late this weekend and possibly early next week as another Pacific storm system impacts the region. There is a chance for strong to severe thunderstorms on Sunday across the eastern plains. - Drier weather with a slow warming trend for mid to late next week. && .SHORT TERM /THROUGH SATURDAY/... Issued at 237 PM MDT Fri May 16 2025 Afternoon visible satellite reveals a broad deck of flat cumulus cloud cover over much of the CWA as transient ridging and cool air aloft continue over the CWA. This cloud cover has kept afternoon high temperatures somewhat cooler than expected by a few degrees. Gusty northwest flow also remains in place along the backside of the departing low pressure to the east, with some obs sites along and east of the Laramie Range reporting wind gusts upwards of 45 mph. As this low pressure center continues to pull away and daytime heating and surface mixing is lost, winds will diminish overnight and a majority of the convective-based cloud cover will dissipate. Expect another cool overnight with lows generally at or slightly below average for mid-May. On Saturday the transient ridge will slide east into the high plains as a deep trough dives into the Great Basin/Four Corners region. While heights aloft will continue to rise a bit through the day, surface flow will quickly change to southeasterly upslope throughout the afternoon with typical terrain-based convergence patterns setting up. With a bit of mid-level moisture increases noted after 21z and strong daytime heating, a few very high-based convective showers and possibly some thunder are possible along and east of the Laramie Range, despite surface dewpoints generally progged to only reach the upper 30s by late afternoon. Farther west, some additional showers and weak thunderstorms will likely form off of the higher terrain of the Sierra Madre and Snowy Ranges. Later in the evening/overnight period, there is some concern for low stratus/fog in the NE panhandle and Southeast Wyoming as deeper moist upslope flow returns ahead of the trough. Forecast confidence remains high throughout the short-term with minimal adjustments made to forecast grids. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... Issued at 237 PM MDT Fri May 16 2025 Sunday begins with low pressure at the surface in the Central/Southern Plains and a secondary system moving into the Wyoming area while at the upper levels a stout Pacific trough will progress towards the Plains and split off into a closed low. Once again the environment will be mostly marginal for severe activity, but a modestly unstable environment including MUCAPE anywhere between 750-1500 J/kg alongside Effective Shear values of 20-40 knots should be enough to fuel stronger thunderstorm activity, primarily impacting the southeastern corner of Wyoming and the southern and central Panhandle of Nebraska. Some stout capping and CIN will need to be overcome however, precluding a stronger threat for severe activity, but any storms that can get going will have the potential for all severe hazards with the strongest risk in Cheyenne County, NE. Plentiful moisture alongside this expected activity could also bring widespread wetting rains, with 0.5-1.5 inches possible from I-25 eastwards, but amounts could be locally heavier or lighter depending on where the strongest storms form and how the evolve. Moving ahead to the start of the week, on the backside of this system another day of precipitation for most of the region is likely but this time only rain and some mountain snow is likely, with amounts around 0.2-0.75 inch expected from the days precipitation. Some light precipitation may linger into Tuesday as this system slowly evolves eastwards across the Mississippi River Valley, but by the middle of the week a flat ridging pattern should evolve, allowing us to warm back into the 70s by Thursday. An isolated shower or storm daily may occur from some weaker embedded systems progressing through the region, but analysis of the ensemble clusters shows that the ridge will continue to build through Thursday and may continue into next weekend. && .AVIATION /00Z TAFS THROUGH 00Z SUNDAY/... Issued at 536 PM MDT Fri May 16 2025 VFR conditions expected over the next 24 hours. Breezy winds should decline through this evening, with speeds overnight generally 10 knots or less. Gusty winds return tomorrow afternoon, but primarily impacting KRWL/KSNY. Low chances of rain expected tomorrow during the afternoon as well between 18-00Z, with a passing shower possible all sites except KCDR/KSNY. Showers could also include lightning, but TS chances are too low to include in TAFs at this time. Clouds lift and lessen overnight, but decks around 10k feet return tomorrow as the rain chances move in. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...MAC LONG TERM...CG AVIATION...CG ####018005069#### FXUS64 KMRX 162343 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 743 PM EDT Fri May 16 2025 ...New AVIATION... .SHORT TERM... (This evening through Saturday) Issued at 308 PM EDT Fri May 16 2025 Key Messages: 2. Severe thunderstorms possible with threats of damaging winds, large hail, and a lower but still significant threat of tornados this afternoon into tonight. 2. Drier conditions for Saturday. Discussion: The atmosphere is primed for severe storms out ahead of the approaching short wave trough, as HRRR/RAP forecast continue to show MLCAPE this afternoon between 2000 and 2500 J/Kg with EBShear of around 50 to 60+ kts. A remnant outflow boundary near the northern Plateau into Southwest VA has the potential to be the focus for storms this afternoon out ahead of tonight's main event, and supercell structures would be likely along with the potential for hail, damaging winds, and an increased threat of a tornado near the boundary. This threat will be conditional on if the cap erodes enough for these additional storms to get going which is still uncertain, and the hi-res CAMS have had a poor handle on this daytime convection overall and unfortunately have added little to the confidence in this scenario so far. Despite the loss of heating after sunset, the instability will remain significant tonight out ahead of the main round of convection as lapse rates steepen with the shortwave trough moving in. The HRRR/RAP forecasts show MLCAPES still around 2000 to 2500 J/Kg as the convection approaches. The LLJ will also increase as the line approaches with 850 mb winds increasing to near 50 kts, and EBShear OF 60+ kts is indicated along with increasing low level shear (with 0-1km shear reaching 35+ kts). Hi-res CAMS and other models have been more consistent in showing a line of convection moving through overnight, with timing still looking most likely to fall between 03z and 09z. All severe hazards look possible, with damaging winds and large hail the primary threats along with a lower, but still significant (around 5 percent within 25 miles of a point), threat of tornadoes. In addition, forecast PW values of 1.6 to 1.8 will be near the climo max, and NAEFS IVT values are forecast to be near climo max as well. This is a strong signal for very heavy rain rates, which may result localized flooding especially in areas that see repeated rounds of rainfall. The highest risk for flooding would likely be across the north given the increased potential for storms there this afternoon. Saturday will turn drier behind this system, with plenty of sunshine and a warm afternoon. && .LONG TERM... (Saturday night through next Friday) Issued at 308 PM EDT Fri May 16 2025 Key Messages: 1. Warm with a some showers and storms around at times Sunday through Monday. 2. Precipitation chances increase for Tuesday into Wednesday, along with a chance for strong to severe storms. 3. Cooler late next week in the wake of a cold front. Discussion: Saturday night looks to be mainly dry, but despite low amplitude upper level ridging slowly building over our area during the Sunday/Monday time frame, weak ripples in the flow are expected to bring showers and thunderstorms to our area at times. By Tuesday, a stronger upper trough will approach the Mississippi Valley with increased chances for showers and thunderstorms Tuesday into Wednesday across portions of the Tennessee Valley and Southern Appalachians, and there is an uptick in the chances for strong to severe storms with this system. Low confidence on how models are handling the latter periods behind the cold front. It may be drier, but some models want to park a closed upper low nearby so at this point the forecast will keep lower chances for showers and storms Thursday and Friday. && .AVIATION... (00Z TAFS) Issued at 726 PM EDT Fri May 16 2025 Conditions will be mainly VFR outside of thunderstorms. The exception is MVFR CIGs in the morning likely at TRI. A line of storms will move through the region around and after midnight. Some storms may be severe with gusty winds being the main threat. Low level wind shear will be present in spots where surface winds are not gusty. The line should move through fairly quickly with clearing expected tomorrow morning with winds becoming more westerly. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 69 87 65 85 / 80 10 10 50 Knoxville McGhee Tyson Airport, TN 66 83 62 82 / 90 10 10 30 Oak Ridge, TN 66 84 62 82 / 90 10 10 30 Tri Cities Airport, TN 64 80 57 78 / 90 20 0 10 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ SHORT TERM... AVIATION...McD