####018005074#### FXUS64 KBRO 031750 AAB AFDBRO Area Forecast Discussion...UPDATED National Weather Service Brownsville TX 1250 PM CDT Fri May 3 2024 ...New AVIATION... .SHORT TERM... (Today through Saturday) Issued at 357 AM CDT Fri May 3 2024 A 500 mb disturbance will approach the western portion of CWA this afternoon. At the surface, the southern extension of the Texas dryline will likely lie just to the west of the area today, extending south into Mexico along the Sierra Madre Oriental range. The combination of a very moist low-level airmass, daytime heating and mid to upper level energy will support the develop of convection over neighboring Mexico. Forecast soundings from along the Rio Grande River suggest SBCAPE values of 2500-4000 J/kg late this afternoon. The isolated to scattered showers and thunderstorms may drift into Zapata, Starr, and Jim Hogg counties later this afternoon and evening. SPC has placed the County Warning Area in a general thunderstorm risk area, generally along and east of US 281/I-69C, with the portions of the Rio Grand Plains and the Upper Valley in a marginal thunderstorm risk for today and tonight. Large hail and locally damaging wind gusts will be the main threats. There is a low chance that these stronger supercells will move into the western portions of the CWA this afternoon and evening. SPC has all of Deep South Texas outlined in a general thunderstorm risk for Saturday. Otherwise, increasing low level moisture and light winds this morning may support patchy light fog, mainly across the Northern Ranchlands and near/over marine areas. Additionally, above normal temperatures will continue through the short-term with highs generally ranging from the low to mid 90s, except for the 80s near the coast, today and Saturday. Overnight temperatures will be warm with lows in the mid to upper 70s, which is a blend of the NBM/CONSShort. Southeast winds will remain moderate to breezy. Elevated seas will result in a Moderate Risk of rip currents at the local beaches today through Saturday. && .LONG TERM... (Saturday Night through Thursday) Issued at 357 AM CDT Fri May 3 2024 Increasing and prolonged heat will be the main concern during this portion of the total forecast. Steadily rising daytime highs will occur throughout the period, with well above normal values likely in the Tuesday through Thursday time frame. Temperatures will near established HEAT ADVISORY criteria on Tuesday, and may reach or surpass the threshold for Wednesday and Thursday as a dryline nudges into the BRO CWFA from the west. Additionally, an enhanced pressure gradient will produce a breezy to windy onshore flow, providing some measure of relief from the heat, especially in shaded areas. However, the strength of the wind will not near or exceed established WIND ADVISORY criteria. && .AVIATION... (18Z TAFS) Issued at 1231 PM CDT Fri May 3 2024 TAF conditions are VFR at the sites as low clouds have scattered out. Still have ceilings above 3 kft, however. High pressure controls the Gulf, with lower pressure to the west, sustaining the seasonal moderate southeast winds across the region. A few storms could be possible upstream toward Laredo this evening, but the lower and even mid RGV, including the TAF sites, should avoid convection. A familiar pattern will occur this evening as ceilings lower to MVFR overnight through Saturday morning. Southeast winds will decrease to light overnight, strengthening to moderate and breezy on Saturday. Light, patchy fog could develop at the TAF sites overnight, but visibility limitations should be no worse than MVFR ceilings. && .MARINE... (Today through Saturday) Issued at 357 AM CDT Fri May 3 2024 Moderate to fresh southeast winds and moderate to sometimes marginally high seas will prevail along the lower Texas Coast through the period. Small Craft Exercise Caution conditions will be likely for portions or all of the lower Texas coastal waters through Saturday. (Saturday Night through Thursday) An enhanced pressure gradient will exist over the western Gulf of Mexico throughout the period. Breezy to strong winds and moderate to rough seas will prevail along the Lower Texas Coast, with both Small Craft Exercise Caution and Small Craft Advisory likely to be needed. && .PRELIMINARY POINT TEMPS/POPS... BROWNSVILLE 90 76 89 76 / 20 10 0 0 HARLINGEN 91 74 91 75 / 20 10 0 0 MCALLEN 93 77 93 77 / 20 10 0 10 RIO GRANDE CITY 93 76 93 76 / 20 20 0 10 SOUTH PADRE ISLAND 82 77 81 77 / 20 10 0 0 BAYVIEW/PORT ISABEL 87 74 86 75 / 20 10 0 0 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ SHORT TERM...54-BHM LONG TERM....64-Katz AVIATION...54-BHM ####018005507#### FXUS63 KPAH 031751 AFDPAH Area Forecast Discussion National Weather Service Paducah KY 1251 PM CDT Fri May 3 2024 .KEY MESSAGES... - Numerous showers and isolated thunderstorms will continue over Quad State, gradually shifting east by midday. Scattered showers and thunderstorms are expected mainly over the southeast half of the region this afternoon. Additional rainfall should generally be a half inch or less. - Very warm temperatures continue will continue through next week. - Scattered showers and storms Saturday through Monday lead into a potentially active period Monday night through Thursday, where some potential will exist for severe thunderstorms and heavy rainfall. && .DISCUSSION... Issued at 349 AM CDT Fri May 3 2024 Weak southwest flow aloft and a rather flat surface pattern will be the rule through Monday. A disturbance will slowly push east of the region today, taking the scattered to numerous showers with it. Most of the activity will be east of the region by 18Z, but showers and a few thunderstorms will remain possible mainly over the southeast half of the region this afternoon and evening. As we head through Saturday, a northern stream trough will push eastward through the upper Mississippi Valley. There has been a persistent signal in the guidance for a broken line of storms to develop along the associated cold front as it moves eastward through Missouri. A few storms could reach southeast Missouri or southern Illinois around sunset. They will be weakening as the attempt to move through the Quad State Saturday night. There could be some moderate instability for storms to work with in the heat of the day Saturday, but convective initiation may be difficult to get. The best chance for afternoon development will be in southern and western portions of the region. Some gusty winds, lightning and isolated heavy rainfall will be possible with any storms Saturday afternoon and evening. Another weak disturbance will lift northeast through the Quad State Sunday night into Monday morning, and then a larger-scale upper trough will quickly lift northeast from the Rockies toward the northern Plains Monday night. The combination of these two features will likely lead to widespread showers and thunderstorms over the Quad State from Sunday afternoon through Monday and possibly into Monday night. The convection would arrive in southeast Missouri Sunday afternoon and then overspread the remainder of the area Sunday night. Some decent instability should be able to develop ahead of the convection, so the storms on the leading edge of the rain shield may have some potential to produce gusty winds as the activity spreads eastward across the region in the afternoon and evening. Wind shear will be weak which should prevent more significant storm organization and severe storm potential. Another round of showers and thunderstorms will be possible with the larger trough Monday night. The wind shear will increase significantly, but it is uncertain if we will be able to develop any instability behind Monday's convection. If we do heat up over southeast Missouri Monday afternoon, a few severe storms will be possible Monday night. For Tuesday we will be in a healthy west southwest flow aloft as an elongated upper trough develops from southeast Canada southwest through the Rockies. This increased flow aloft will allow for much stronger southerly flow in the low-levels across the Quad State Tuesday and Wednesday. Gusts up to 30 mph are a good bet, and we may need to issue a Lake Wind Advisory both days. There is a decent signal in the latest guidance for multiple rounds of convection to develop as minor disturbances move through the region from Tuesday through Thursday. Given the west southwest flow aloft, a decent cap should be in place and allow for significant instability to develop each day, depending on remnant cloud cover from the previous day's activity. With strong wind fields expected, each round of convection could pose a severe threat, and with each round, the heavy rainfall and flooding threat would increase. By Friday the upper trough is expected to pivot eastward and bring an end to the onslaught, but we could end up in the dreaded dirty northwest flow heading into Mother's Day weekend. Until this upper trough can push a substantial cold front through the region, allowing surface high pressure to build in, temperatures will remain well above normal. Of course, the daily chances of convection should help to mitigate the impact of the prolonged warm weather. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 1211 PM CDT Fri May 3 2024 MVFR cigs will improve this afternoon at most sites. Isolated to scattered SHRA expected this afternoon with CIG and Visb restrictions possible near any of this activity. TSRA appear possible but confidence is too low to mention in the TAFs. Winds relax overnight with a very moist boundary layer leading to fog development. IFR is forecast for all sites by morning. Fog will scatter out shortly after sunrise with VFR expected the rest of Saturday. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...None. MO...None. IN...None. KY...None. && $$ DISCUSSION...DRS AVIATION...AD ####018005742#### FXUS62 KTAE 031751 AFDTAE Area Forecast Discussion National Weather Service Tallahassee FL 151 PM EDT Fri May 3 2024 ...New AVIATION... .UPDATE... Issued at 1040 AM EDT Fri May 3 2024 Made a few minor tweaks to the PoP forecast increase it slightly. Otherwise, no other changes were made. && .NEAR TERM... (Today and tonight) Issued at 351 AM EDT Fri May 3 2024 Onshore flow continues today and tonight as the Bermuda high remains parked off to the east. Mid to upper level riding is expected to weaken a bit and shift further south with the ridge axis closer to the FL Peninsula. This along with increasing moisture across the area will allow for a bit more coverage of scattered showers and thunderstorms this afternoon and evening. Forecast soundings show DCAPE near 800-900 J/kg this afternoon, so a few of the storms could be strong to severe with gusty winds the primary hazard. High temperatures today are forecast a tiny bit cooler than yesterday due to the increase in cloud cover and the shifting of the ridge axis to the south. Highs are still forecast in the upper 80s to low 90s with lows overnight in the mid to upper 60s. && .SHORT TERM... (Saturday through Sunday night) Issued at 351 AM EDT Fri May 3 2024 Scattered to widespread showers and thunderstorms are possible Saturday afternoon as an H5 shortwave moves through the Southeast. A few showers and storms are possible along the sea breeze as it pushes inland. However, the best opportunity for rain will be closer to the shortwave in southwestern Georgia. Additional showers and storms are possible Sunday as the shortwave lifts out of the region. Highs will climb into the upper 80s to lower 90s around the region both days with lows in the middle to upper 60s Saturday night. && .LONG TERM... (Monday through Thursday) Issued at 351 AM EDT Fri May 3 2024 Showers and thunderstorms remain possible Monday afternoon, mainly along the I-75 corridor, before ridging aloft takes over the rest of the work week. Surface high pressure situated between Bermuda and the Bahamas coupled with H85 temperatures climbing to between 18 to 20C will support highs in the lower to middle 90s by the middle of next week. An increase in low-level moisture will also push overnight lows from the middle 60s Monday and Tuesday night to the upper 60s to lower 70s, even away from the coast, by Wednesday night. While records are not explicitly forecast, one or two locations could flirt with their record highs Wednesday and/or Thursday of next week. && .AVIATION... (18Z TAFS) Issued at 141 PM EDT Fri May 3 2024 Mainly VFR conds away from t-storms with a south to SW wind and mix of upper/lower clouds. Isolated convection is expected to focus mainly around the interstate corridors this aftn. Highest confidence in being impacted by thunder is VLD where an evening tempo group was introduced amidst prevailing VCTS. Lingering showers appear likely tonight, then MVFR cigs/vsbys aim to develop in the pre-dawn hrs at ECP/TLH. Better convective coverage is fcst tmrw just after the end of this TAF cycle. && .MARINE... Issued at 351 AM EDT Fri May 3 2024 High pressure in the Atlantic will lead to tranquil boating conditions through the period. Light winds, generally out of the south-southeast, are expected with seas around 1 to 2 feet into the weekend. There is a slight chance of showers and thunderstorms Saturday and Sunday. && .FIRE WEATHER... Issued at 351 AM EDT Fri May 3 2024 Warm and moist conditions will continue today and over the weekend with rain chances increasing on Saturday. A few showers and storms will be possible this afternoon and evening, with more widespread showers and storms possible all day Saturday. Winds may fluctuate between southeast and southwest over the next several days. A seabreeze is likely to develop and move inland each afternoon. Very good to excellent dispersions are also likely each afternoon with very high mixing heights. && .HYDROLOGY... Issued at 351 AM EDT Fri May 3 2024 The last of the Flood Warnings from the April 10/11th flood event will be cancelled sometime this morning as the Suwannee River at Manatee Springs drops below Minor Flood stage. Several sites along the Suwannee remain in Action Stage along with the Aucilla at Lamont and St Marks at Newport. Scattered showers and thunderstorms are possible the next couple of days and could lead to localized 0.25 to 0.75 inches of rain. Outside of that, no flooding is anticipated at this time over the next several days. && .SPOTTER INFORMATION STATEMENT... Spotter activation is not requested. However, spotters are always encouraged to safely report significant weather conditions when they occur by calling the office or tweeting us @NWSTallahassee. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 89 68 87 66 / 20 10 60 20 Panama City 85 69 85 68 / 10 10 20 10 Dothan 89 68 88 66 / 20 20 40 20 Albany 90 68 87 65 / 20 30 70 30 Valdosta 89 68 85 66 / 40 40 70 30 Cross City 89 66 87 66 / 20 10 50 20 Apalachicola 80 69 80 70 / 10 10 10 10 && .TAE WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AL...None. GM...None. && $$ UPDATE...KR NEAR TERM...Merrifield SHORT TERM...Reese LONG TERM....Reese AVIATION...IG3 MARINE...Reese FIRE WEATHER...Merrifield HYDROLOGY...Reese ####018007530#### FXUS63 KBIS 031754 AFDBIS Area Forecast Discussion National Weather Service Bismarck ND 1254 PM CDT Fri May 3 2024 .KEY MESSAGES... - Expect low to medium chances (20 to 60 percent) for rain showers through the day, mainly across the northern half of western and central North Dakota. Some light snow may mix in across the west this morning. - Temperatures will warm through the weekend, with windy conditions on Sunday. - Chances for rain return Sunday evening and continue through the work week. The wettest period will Monday through Tuesday when most of western and central North Dakota will see medium to high chances (60 to 90 percent) of rain. && .UPDATE... Issued at 1229 PM CDT Fri May 3 2024 The upper level low continues to push eastward with some wrap around showers moving across central North Dakota. Cumulus clouds have expanded across the whole state leading to broken cloud cover. No updates are needed at this time as the forecast remains on track. UPDATE Issued at 959 AM CDT Fri May 3 2024 Some showers continue to move across northeastern and central North Dakota. Cloud cover continues to expand across the state as instability and wrap around precipitation. Winds will continue to turn to northwesterly as a pressure trough moves across the region. No other updates are needed at this time. UPDATE Issued at 622 AM CDT Fri May 3 2024 The forecast looks to generally be on track this morning. We have seen a few radar echoes across the northwest and north central, potentially bringing a few rain drops to the surface as they pass overhead. Some more substantial showers have been observed on the Williston radar over the past couple of hours, extending from around Culbertson Montana southeast down to around Grassy Butte. More showers should continue to develop across the northwest and north central through the day. No major changes were needed for this update. && .DISCUSSION... Issued at 333 AM CDT Fri May 3 2024 Early this morning, western and central North Dakota sits under the influence of broad quasi-stationary troughing overhead. The upper low that brought showers and thunderstorms to the region yesterday will continue to eject out into Ontario to our northeast as the next upper low rotates down into northwest North Dakota from southern Saskatchewan later today. This low will be the trigger for showers to develop through the day (20 to 60 percent chance), mainly across the northern half of the forecast area (best chances along the International Border). Some light snow may even mix in across the west briefly this morning. RAP soundings suggest that instability will be limited this afternoon and evening with MUCAPE values mainly maxing out in the 100 to 200 J/kg range. While a stray rumble of thunder or two cannot be ruled out, confidence is not high enough to include mention of thunder in the gridded forecast at this time. Precipitation chances will diminish to the northeast tonight as the upper level trough finally starts to move out to our east, transitioning western and central North Dakota into northwest flow aloft on Saturday. Surface high pressure will also slide in on Saturday, leading to diminishing clouds from west to east and slightly warmer temperatures. Highs will remain cool today, ranging from the mid 40s northeast to the mid 50s southeast and then by Saturday, highs will range from the lower 50s to lower 60s. An upper level ridge axis then approaches Saturday night and crosses the state on Sunday. This will mean even warmer temperatures with forecast highs ranging from the lower 60s to lower 70s. Behind the ridge axis, a deep trough will approach from the west, transitioning western and central North Dakota into meridional flow aloft. As this trough approaches, a surface low will deepen to around 990 mb or less over eastern Montana. This will lead to strong warm air advection, pressure falls, and a rapidly tightening pressure gradient on Sunday for our area. So, while highs will be fairly mild, it will be windy with soundings suggesting the potential for 40 knots or so available to mix down from the top of the mixed layer. The potential for gusts up to 45 mph seems reasonable for now and an eventual Wind Advisory seems like a decent probability. The story then turns to the approaching strong storm system and widespread rain event Sunday night through the week. The sub 990 mb surface low will continue to deepen as the upper level trough starts to take on a negative tilt and nudges into the northern Plains. Widespread showers and some thunderstorms will develop through the day and night, but dry slotting is likely to setup somewhere depending on the eventual track of the low. While thunderstorm chances will be better than in previous days, instability still appears to be somewhat lacking. However we could see some MLCAPE values up to 500 J/kg with deep layer shear forecast to range from around 35 to 45 knots. So, the severe weather potential appears to be fairly low but a couple of strong storms may be on the table. The wettest period will generally be Monday through Tuesday (widespread 60 to 90 percent chances for showers) and another potential hazard could be heavy rain, especially if heavier showers/storms can train over some of the same areas. NBM 72-hour probabilities (ending 12z Thursday) don't suggest anything too dramatic with most of the west and central in medium probabilities (40 to 70 percent) for an inch of rain or more (the one exception being the James River Valley where the consensus currently wants to place most of the dry slotting). When we increase that threshold to two inches, the probabilities fall off mainly into the 10 to 30 percent range. However, it is worth noting that the NAEFS is showing Integrated Water Vapor Transport, PWATs, and 850 mb specific humidity in the 97.5th percentile or greater for this time of year in the Monday through Tuesday time frame. Thus, there may be an opportunity here for some heavier rainfall in a few locations. The upper low will start to wind down by mid week but will be slow to kick out into the Great Lakes region given a stubborn east coast ridge. Low to medium chances (20 to 60 percent) for showers will continue through at least Thursday. Highs on Monday will not be quite as warm as Sunday given widespread clouds and rain. However, we should still see highs in the 60s. With the cool wet pattern continuing, highs will mainly dip back into the lower 50s to lower 60s for most of the rest of the work week. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 1229 PM CDT Fri May 3 2024 MVFR conditions will continue for portions of North Dakota this afternoon due to low clouds. Clouds will slowly rise to VFR across the southern half of the state this afternoon before they dissipate later this evening. Breezy northwest winds will impact all terminals this afternoon with winds decreasing by the evening hours. Isolated showers are possible this afternoon across the state with showers diminishing by sunset. && .BIS WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Johnson DISCUSSION...ZH AVIATION...Johnson