Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/02/24


Area Forecast Discussion
National Weather Service Austin/San Antonio TX
913 PM CDT Wed May 1 2024 ...New UPDATE... .UPDATE... Issued at 905 PM CDT Wed May 1 2024 First round of storms advanced across Blanco county through the I-35 corridor from near Austin through Williamson county producing very healthy rainfall rates and some flooding. The storms also strengthen enough to where some hail and strong winds were possible as well. Updated the PoPs given the latest observational/radar trends and a slightly better initiation with the 00Z HRRR. A secondary round for strong to severe convection and locally heavy rainfall is expected to develop across the Hill Country and spread eastward into the I-35 corridor and eventually the coastal plains. An uptick in the radar trends recently across the Hill Country seems to support this idea. Locally heavy rainfall and flooding remains the greater concern, but some individual cells could become severe with damaging winds and large hail as the primary. severe hazards. Have trimmed the PoPs to the west, especially closer to the Rio Grande. Severe Thunderstorm Watch remains in effect through 2 AM CDT and a Flash Flood Watch through 7 AM CDT Thursday for portions of South-Central Texas. && .UPDATE... Issued at 757 PM CDT Wed May 1 2024 A Severe Thunderstorm Watch is in effect across portions of the I-35 corridor from near Schertz northward through Williamson county, the Hill Country, and portions of the coastal plains through 2 AM CDT. Primary severe weather hazards include damaging winds and large hail. Additionally, locally heavy rainfall will continue and remains the greatest concern tonight with the pre-existing Flood Watch remaining in effect through 7 AM CDT. && .SHORT TERM... (Tonight through Thursday night) Issued at 209 PM CDT Wed May 1 2024 Key Points * Isolated to scattered strong to severe storms are possible this afternoon through tonight with wind and hail the main threats. Isolated tornado can`t be ruled out. * Heavy rainfall and flooding will possible for the eastern two- thirds of the area. * Flood Watch has been issued for portions of the Hill Country, I35 corridor, and Coastal Plains. Mostly cloudy skies prevail across South-Central Texas this afternoon with temperatures in the 70s to lower 80s. Winds remain out of the southeast with speeds near 10-15 mph on average. Starting to see an uptick of shower activity across the area and as we progress into the afternoon, high-res model guidance is all consistently showing this activity growing in coverage and intensity. Some of this should bring some locally heavy rainfall and the possibility of a strong storms this afternoon and evening. The WRF/ARW suite of the high res models are much more bullish with rain amounts than the HRRR with some values near 5-7 inches in isolated places this afternoon. The 18z HRRR shows some pockets of 1-3 inches with the afternoon activity and think this solution should be the most favored one. However, even with the light returns on radar, activity is very efficient rain producers given PW values near 2 inches which is off nearly unheard of for this time of year. The focus for shower and thunderstorm activity late this evening and overnight will be out west as convection in West Texas possibly moves into the northern two-thirds of the area. Could see some severe storms with this activity with wind gusts then hail as the main risks. Heavy rainfall will also be possible with this activity with additional rainfall totals of 1-3 inches likely with some possible isolated higher amounts. We issued a Flood Watch earlier for portions of the Hill Country, I35 corridor, and Coastal Plains through 7 AM. Given this moist airmass it will not take much to produce heavy rainfall and will likely see some locations see isolated amounts near 5 inches and this could produce some flash flooding. All activity should be mostly east of the forecast area after 10 AM tomorrow with just some possible very isolated activity continuing tomorrow during the day. Highs tomorrow will be in the 80s for most areas with some mid 90s near the Rio Grande. Lows tonight and tomorrow night will be in the middle 60s to middle 70s. && .LONG TERM... (Friday through Wednesday) Issued at 209 PM CDT Wed May 1 2024 A shallow upper level trough over the southwest will keep southwesterly flow over TX through the end of the week. A series of shortwave troughs will move through this pattern. Combined with daytime heating this will generate chances for showers and thunderstorms each afternoon and evening Friday and Saturday. Sunday the upper pattern will become progressive and the trough will push into west TX. This will mean chances for convection through the day Sunday. None of this activity looks strong nor any rainfall excessive. A low amplitude ridge will push up from the Gulf bringing dry weather. This ridge will settle over the region for the first half of next week. This will lead to warming temperatures with highs reaching the lower to middle 90s over the eastern half of the CWA and upper 90s to near 105 over the west. && .AVIATION... (00Z TAFS) Issued at 617 PM CDT Wed May 1 2024 Low confidence continues regarding the exact placement and timing of rain showers and convection over the first 8 hours or so in the TAF period, mainly at the I-35 sites (KAUS, KSAT, KSSF). KDRT best chance for any convection is early in the period. Primarily MVFR to IFR conditions are expected throughout the overnight into Thursday morning at the sites but pockets of VFR and LIFR will be possible at times. Expect for conditions to improve to VFR levels at all sites from Thursday afternoon into Thursday evening. Winds outside from convective influences should remain around 12 knots or less. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 68 83 71 86 / 80 50 20 20 Austin Bergstrom Intl Airport 68 83 71 85 / 80 40 20 20 New Braunfels Muni Airport 69 84 72 87 / 70 30 10 20 Burnet Muni Airport 68 82 70 84 / 70 30 20 20 Del Rio Intl Airport 75 95 76 97 / 20 10 0 30 Georgetown Muni Airport 68 82 71 84 / 80 50 20 20 Hondo Muni Airport 68 83 70 89 / 50 10 10 20 San Marcos Muni Airport 68 84 71 86 / 80 40 10 20 La Grange - Fayette Regional 71 83 73 85 / 70 50 20 20 San Antonio Intl Airport 70 83 72 87 / 70 30 10 20 Stinson Muni Airport 71 84 73 89 / 50 30 10 20 && .EWX WATCHES/WARNINGS/ADVISORIES... Flood Watch until 7 AM CDT Thursday for Bandera-Bastrop-Bexar- Blanco-Burnet-Caldwell-Comal-De Witt-Fayette-Gillespie-Gonzales- Guadalupe-Hays-Karnes-Kendall-Kerr-Lavaca-Lee-Llano-Travis- Williamson-Wilson. && $$ Short-Term...Brady Long-Term...05 Aviation...Brady
Area Forecast Discussion
National Weather Service Goodland KS
749 PM MDT Wed May 1 2024 .KEY MESSAGES... - A few thunderstorms may develop in northwest Kansas late this afternoon, south of Interstate 70 and east of Highway 25. An isolated supercell is possible, mainly between 4-8 PM MDT, capable of producing large hail, damaging winds and perhaps a tornado. - More widespread thunderstorms will develop north of I-70 in northwest KS and southwest NE this evening. A few severe storms capable of producing large to very large hail are possible, mainly between 8pm-3am MDT. Storms will rapidly exit the region (into south-central and southeast NE), thereafter. - Scattered thunderstorms are anticipated to develop over portions of northeast CO and northwest KS Friday afternoon. Severe storms capable of producing damaging winds are possible, mainly late Fri aft/eve, when storms may increase in coverage and track SE toward southwestern and south-central KS. && .UPDATE... Issued at 734 PM MDT Wed May 1 2024 Storms continue to develop over NE Colorado into SW Nebraska this evening. A Severe Thunderstorm Watch is in effect for I-70 and north counties until 1 AM MDT/2 AM CDT. Hazards include a couple of tornadoes, large hail, and damaging wind gusts. These storms , some as embedded supercells, seem to developing along a line from Dundy County to Kit Carson county as of 7:50 PM MT. Storms will move individually towards the northeast to east.The Tornado Watch for Wichita, Logan, and Gove continues until midnight CDT. The cell in Gove County has a history of giant hail and rotating wall clouds/funnel clouds. && .SHORT TERM /THROUGH SATURDAY NIGHT/... Issued at 200 PM MDT Wed May 1 2024 Most of the area remains cloudy and cool this afternoon, with some clearing noted on satellite across southern and western portions. A warm front was surging northward across southwest Kansas, and at 19z was roughly along a Garden City to Jetmore line. Meanwhile, a cold front was moving out of the Colorado Front Range in response to an upper level shortwave trough. Not much has changed from previous thinking. The warm front to the south has a chance of reaching southern Logan and Gove counties by later this afternoon, which would potentially put them in the warm sector which is very unstable. Latest RAP analysis shows up to 3000 j/kg in that area with bulk shear values of up to 60 kts. In fact, latest runs of the HRRR and RAP show initiation occurring by 21-23z around the Lake Scott area. Any discrete supercell in that location would be capable of producing large hail, damaging winds and perhaps a tornado. Those storms seem to fade by 02-03z, and attention turns to the northwest where more widespread convection will be getting underway in response to the upper dynamics and surface cold front. While storms may initially be surface based, expecting mostly elevated storms this evening across much of northwest Kansas and southwest Nebraska. MUCAPE values will be around 1500-2500 j/kg and shear values around 60 kts. So elevated supercells will certainly be possible, capable of producing large to very large hail and perhaps a few isolated damaging wind gusts. This risk will move east through the late evening hours and spill into the overnight hours in far eastern areas like Norton and Graham counties, finally exiting to the east by 07-09z. There will also be a risk of excessive rainfall in the northeast part of the area, particularly from McCook to Oberlin and Norton, where mean rainfall amounts are around 1 inch and 90th-95th percentile rainfall amounts are in the 1 to 2 inch range. Low temperatures will range from the upper 30s in Colorado to the middle 40s in north central Kansas. Thursday will be breezy in the morning, then diminishing winds, mostly sunny and mild in the afternoon with highs in the 60s. A weak shortwave trough comes out of Colorado in the afternoon and evening hours bringing a chance for scattered showers and perhaps an isolated thunderstorm through the evening and overnight, with best chances in northeast Colorado. Low temperatures will range from the upper 30s to lower 40s. The pattern does not change much on Friday. Another shortwave trough moves out of the Rockies in the afternoon, a bit stronger than the one on Thursday, with increasing chances for showers and thunderstorms with the associated surface cold front. Showers and storms will be likely by Friday night as the front moves through the area. Surface based instability will be rather limited, generally under 1000 j/kg is forecast ahead of the front, but deep layer shear values will be 40-50 kts. Those parameters may be sufficient for a few severe storms capable of producing hail up to quarter size and gust winds. Instability rapidly decreases after about 03z as the front races southeast, probably ending the severe threat. High temperatures will be in the upper 60s to lower 70s and lows Friday night ranging from the lower 30s in northeast Colorado to the middle 40s in north central Kansas. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... Issued at 223 PM MDT Wed May 1 2024 The extended forecast begins with the Tri-State area under southwest flow on Sunday. A close upper low will be over Northern California, and sliding to the southeast through the day. There is a 20-40% chance of a few showers and isolated thunderstorms in the morning across portions of the Tri-State area. Thunderstorm chances (20- 40%) will continue across the area heading into the afternoon and evening hours. Monday, southwest flow persists over the area with a tightening pressure gradient, in advance of the upper trough. Models are bringing the trough through the Tri-State area during the day on Monday, with a closed low taking a sharp turn to the north, into the Dakotas. A warm front will be draped across portions of South Dakota and Nebraska, with warm air coming up into the area. Expected high temperatures will range from the upper 60s over portions of northeastern Colorado, to the mid to upper 70s for areas south of Interstate 70. A few thunderstorms will be possible Monday afternoon, mainly for locations along and north of I-70. Westerly to southwesterly flow sets up over the region Tuesday and Wednesday. Dry conditions are expected through this timeframe. High temperatures each day will range from the upper 60s to mid-70s each day. Lows will range from the upper 30s to low 40s in eastern Colorado, to the mid-40s for the easternmost portions of the CWA. && .AVIATION /00Z TAFS THROUGH 00Z FRIDAY/... Issued at 525 PM MDT Wed May 1 2024 Low-end VFR to MVFR conditions expected the first few hours due to low ceilings over KMCK and KGLD. Storms over Northeast Colorado are expected to continue moving ENE which will impact the KGLD terminal possibly ~02Z-06Z. KMCK may be impacted from ~02Z-08Z. There is also a slight risk for hail with any stronger thunderstorm. Low ceilings persisting through the overnight. A return to VFR expected at both terminals early Thursday morning. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...None. CO...None. NE...None. && $$ UPDATE...KMK SHORT TERM...024 LONG TERM...Wekesser AVIATION...KMK
Area Forecast Discussion
National Weather Service Houston/Galveston TX
701 PM CDT Wed May 1 2024 ...New AVIATION... .SHORT TERM... (This evening through Thursday Night) Issued at 333 PM CDT Wed May 1 2024 We continue to anticipate a heavy rain event overnight and into tomorrow, which will pose a risk of flash flooding while also exacerbating ongoing river flooding. A Flood Watch, which now including Harris County as well as other locations along and north of the I-10 corridor within the original Watch, will be in effect between 10 PM tonight and 7 PM tomorrow. Additionally, this line of storms will pose a threat of severe weather, particularly strong wind gusts, as it moves through the area. Models still remain in good agreement in showing the progression of a robust midlevel trough, which will move across the area overnight and into tomorrow. Environmental conditions remain favorable for heavy rain, with abundant moisture availability (PWs of around 2.0 in) that will be sustained by steady onshore flow. Soils remain well- saturated from Sunday/Monday`s storms, which, combined with elevated river and creek levels, will make flash flooding quicker to develop. Furthermore, SB instability in the range of 1500 J/kg and effective layer shear of 40+kt during the overnight/early tomorrow period will both support heavy rain and the potential for strong to severe wind gusts. The approach of the aforementioned trough is expected to induce the development of an MCS to our northwest, with the complex of storms moving from NW to SE over the course of the overnight and morning hours. A few isolated storms ahead of the line are possible, and these storms may result in a few brief heavy downpours. However, the main heavy rainfall window looks to remain concentrated around the 2 AM to 12 PM timeframe. In terms of rainfall totals, there remains quite a bit of uncertainty across the most recent iterations of available HiRes models as well as the HREF. Generally, the axis of heaviest rainfall has shifted to the south since yesterday, with most locations along and north of the I-10 corridor poised to receive average rainfall amounts between 2-5". Some localized totals may reach 6-9", although the exact location and extent of any higher amounts will be dependent on exactly how the development of the line unfolds. A faster-moving line, as depicted in some of the more recent HRRR runs, would favor less instances of localized higher amounts but would also result in an increased risk of strong/severe wind gusts with the development of a stronger cold pool behind the line. With slower-moving solutions, we`d expect to see greater instances of the locally higher amounts. A few solutions also show some redevelopment of scattered storms tomorrow afternoon, which could produce a few more locally heavy downpours. While uncertainty remains in the forecast, we nonetheless still anticipate a widespread flooding threat with the threat of severe weather also still present. In addition to the threat of street flooding, these additional rains will also contribute to the ongoing river flooding across the area, particularly across portions of the San Jacinto and Trinity basins. This period will remain a time to be weather aware and weather prepared...with flooding and strong winds potentially impacting the morning commute across the area, caution should be exercised while traveling. Having multiple ways to receive warnings remains very important! Cady && .LONG TERM... (Friday through next Tuesday) Issued at 333 PM CDT Wed May 1 2024 The long-term forecast period continues to show a series of upper- level disturbances moving through a quasi-zonal flow through the early weekend. Onshore winds will continue to pull moisture into SE Texas from the Gulf, causing another increase in PW values Friday (between 1.5 and 1.8 inches). Highest PW values are reflected over an area generally north of I-10 and east of I-45. Furthermore, the 500mb layer shows ripples in the overall flow with embedded vort maxes crossing through the northern portion of the CWA. In addition to the aforementioned ingredients, models continue to indicate the potential for a 925mb LLJ to redevelop Friday (guidance is pretty spread out with regards to the strength of the LLJ). This setup will allow for a few more rounds of showers and storms to move through, again with highest chances remaining in the area north of I-10 and east of I-45. Low-level moisture hangs around through the weekend; however, precipitation chances remain on the lower end (20% or less) on Saturday. Upper-level flow becomes more zonal, the LLJ dissipates, and drier air moves into the mid-levels which will help reduce the coverage of precipitation. Any precipitation on Saturday will likely be diurnal in nature (plenty of CAPE with daytime heating eroding the cap) and the highest chances once again reside in the NE portion of the CWA. Given the already saturated soils in the Brazos Valley/Piney Woods in addition to the forecasted rainfall for the short-term period, any further rainfall will enhance the potential for flash flooding and river flooding. It is important to bear in mind that rivers can respond anywhere from a few hours to days after a significant rainfall event. Please continue to monitor the forecast, have a plan for yourself, family, and pets, and have multiple ways to receive alerts. The active weather pattern appears to settle down early next week as upper level ridging prevails and leads to drier and warmer conditions. Highs for next week will reach into the upper 80s to low 90s. Dew points in the low 70s will lead to more muggy condition as well. Adams && .AVIATION... (00Z TAF Issuance) Issued at 627 PM CDT Wed May 1 2024 Mostly VFR conditions are prevailing across SE TX at this time, along with a couple of storms as well. Fortunately, this activity does seem to be weakening as it moves out of the CWA. However, chances for more development remains on track for later tonight on through early Thurs morning. Have tweaked the timing of these storms to start (from west- east) just after midnight for CLL...with this activity tracking E/SE. The best chances for storms/heavy rainfall are going to be across the northern CWA. But gusty winds and reduced VSBYs will be possible with any of the stronger storms. We could get another round of activity by tomorrow afternoon (depending a whole lot on what happens overnight), before conditions finally improve by tomorrow evening areawide. 41 && .MARINE... Issued at 333 PM CDT Wed May 1 2024 Moderate onshore winds are expected through much of the forecast period. Winds may approach Advisory levels on Thursday. Seas will generally range between 4 to 6 feet over the offshore waters and 2 to 5 feet over the nearshore waters. In addition to increased winds, there is an increased risk for strong rip currents to occur across the Gulf facing beaches over the next few days. Periods of showers and storms can be expected through the end of the work week. && .HYDROLOGY... Issued at 243 AM CDT Wed May 1 2024 River flooding continues, particularly along portions of the Trinity and San Jacinto rivers. The following river points continue to remain at or above flood stage as of this morning: - Trinity River (Goodrich): Major Flood Stage - Trinity River (Liberty): Moderate Flood Stage, rising to Major Flood Stage today - Trinity River (Riverside): Moderate Flood Stage - Trinity River (Romayor): Action Stage, rising to Minor Flood Stage today - Trinity River (Moss Bluff): Minor Flood Stage - Menard Creek (Rye): Moderate Flood Stage - San Jacinto (New Caney): Major Flood Stage Additional rainfall over the next few days, both over the area and upstream, may result in further water level rises and prolonged river flooding. Remember to heed any instructions from your local officials and to never travel through flooded areas or roadways. Please monitor updated forecasts via the NWS AHPS website and/or the new NWS NWPS webpage (https://water.noaa.gov/) as the river flood threat continues. 24 && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 70 82 72 83 / 80 70 30 50 Houston (IAH) 73 84 73 83 / 60 60 40 50 Galveston (GLS) 74 80 74 80 / 40 30 50 30 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...Flood Watch from 10 PM CDT this evening through Thursday evening for TXZ163-164-176>179-195>200-210>213-300-313. GM...Small Craft Should Exercise Caution through Thursday afternoon for GMZ330-335-350-355-370-375. && $$ SHORT TERM...Cady LONG TERM....Adams AVIATION...41 MARINE...Adams
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
823 PM CDT Wed May 1 2024 .KEY MESSAGES... - Level 1 risk of severe weather on Thursday has been expanded eastward to near I-55, though smaller scale features from leftover morning showers/storms may play a role in severe weather extent - Warmest period through this weekend will be on Thursday, with widespread highs in the mid 80s - Numerous chances for showers and thunderstorms over the next several days, though a significantly long dry period is hard to pin down right now && .UPDATE... Issued at 822 PM CDT Wed May 1 2024 This evening, a weak shortwave trough is noted over south central Missouri with scattered thunderstorms ahead of this feature south of the St Louis area. This wave will move east late this evening and overnight with some potential for a few showers and storms mainly near and south of I-70. 00Z ILX sounding indicated very dry air is in place below 800mb with an overall dry column (PWat 0.60 inches). Given the weak forcing, unfavorable diurnal timing, and dry antecedent conditions, convection will struggle as it moves into Illinois. HRRR is now calling for dry conditions through the night, though the RAP/NAMNest continue to show decaying showers reaching southern parts of the forecast area late this evening. Have lowered PoPs some to account for observed conditions and model trends, but maintain at least a slight chance mention in the SE this evening. Further NW across the Illinois River Valley, strengthening WAA will overspread the region late tonight and could bring another chance of showers and storms. Models have mostly slowed the arrival of precip until Thursday morning, so have lower PoPs accordingly. Deubelbeiss && .DISCUSSION... Issued at 307 PM CDT Wed May 1 2024 An active weather pattern will remain in place over the next week. In the shorter range, a broad upper low currently over northern Montana will gradually wobble eastward the next 36-48 hours, before finally lifting toward Hudson Bay on Friday. However, a stronger upper low moves onto the West Coast this weekend, then moves toward the central Rockies. The longer range synoptic models are in decent agreement with this feature eventually ending up in Montana or North Dakota as well. Thus, the overall upper pattern remains of Pacific origin. A lot of our weather will hinge on various waves ejecting ahead of, or circulating around, these features. Early afternoon surface map shows the wind shift with the front has settled south of I-70, while the drier air lags behind a bit. Dew points are down into the 40s west of I-55, but still linger in the 60s as far north as Mattoon and Paris. Radar mosaics show a cluster of storms developing over north central Arkansas, with the morning HiRes-ARW run handling it the best. Its solution shows a general development of scattered convection over central and southern Missouri this afternoon, extending eastward along the boundary toward early evening. Much of this is diurnally driven, and isolated PoP`s are in the forecast along it. However, more of a focus is expected after midnight, with elevated convection as the front lifts northward. The various high-res models have some disagreements with the eastward extent, and overall PoP`s after midnight haven`t been changed too much from previous, generally in the 30-40% range north of I-72. Any lingering showers from this elevated activity should be north of the forecast area by mid morning. Latest SPC Day2 outlook has expanded the level 1 (marginal) risk eastward to near I-55, though some complications arise if the overnight activity manages to form an MCS. We`ll fully be in the warm sector, with over 1,000 J/kg of surface based CAPE, though overall bulk shear parameters would only be more favorable west of the Illinois River. However, if the morning activity manages to get any boundaries in place, an uptick in activity is possible. For now, most daytime PoP`s will be confined to areas near and west of I-55, with activity spreading eastward in the evening. Rain chances linger into Friday, though primarily east of I-55. Going into the longer range, a shortwave is expected to track out of the Plains on Saturday. The day may start out dry, but scattered showers/storms are expected by afternoon as the front approaches. This front is expected to get hung up near or just south of the Ohio River later in the weekend, where we again get to monitor its northward return early next week as the upper low moves toward the central Rockies. Deterministic models suggest a period of dry weather Monday night and early Tuesday, though ensemble probabilities are harder to pin down a definite period. Earlier CSU machine learning probabilities suggested Tuesday as a potential day to watch for strong/severe storms, with timing still looking favorable, but it`s still way out there to get any real specifics. Geelhart && .AVIATION... (For the 00z TAFs through 00z Thursday Evening) Issued at 629 PM CDT Wed May 1 2024 Low pressure will lift across the central Plains overnight and into the Upper Midwest Thursday with a trailing cold front reaching the Illinois River late in the period. Ahead of the low, N/NE winds in place this evening will veer to SE overnight and eventually SSW midday Thursday with gusts picking up to around 20 kt during the day. A few spotty showers are possible overnight, though confidence is low in location/coverage, but currently favors the I-72 corridor where a VCSH mention is included in the forecast. Otherwise expect dry conditions until the front comes in late in the period with showers and thunderstorms accompanying a wind shift to the northwest. Deubelbeiss && .ILX WATCHES/WARNINGS/ADVISORIES... None. && $$
Area Forecast Discussion
National Weather Service Jackson MS
1004 PM CDT Wed May 1 2024 ...New MESOSCALE UPDATE... .MESOSCALE UPDATE... Issued at 1002 PM CDT Wed May 1 2024 Rest of tonight... Perturbed pattern persists across the western half of the nation, with cold core low centered across northern MT/stronger longwave jet progged to round the base of the trough in the Pacific Northwest. Split flow exists across the southern half of the nation, with shortwave moving into the region aiding in convective development across eastern TX. With expected low-level southerly return flow expected to pick up overnight on the western fringes of the mean ridge, at the sfc/aloft, over the Carolinas/Atlantic seaboard, low stratus/fog formation is possible across the southern half of the area. HREF probs continue to indicate decent probs for fog, >30% into the I-20 corridor. Added an "Elevated" for probs of areas of dense fog while the "Limited" was expanded to include the I-20 corridor. Held off on an advisory for now. Updates are out. No major changes to sensible weather forecast, with seasonably warm lows in the low 60s southeast of the Natchez Trace corridor while mid-upper to the northwest & increasing clouds. /DC/ && .DISCUSSION... Issued at 314 PM CDT Wed May 1 2024 Tonight into Tomorrow: The forecast remains tricky to nail down details even in the short- term, because so much of what may happen in our forecast area will depend on the mesoscale developments upstream to our west in Texas and Oklahoma. No weather is expected the rest of this afternoon, but building humidity and returning low-level flow tonight may bring a better chance for fog to develop in southern Louisiana and Mississippi by early tomorrow morning. HREF probabilities of dense fog in the Pine Belt reach about 30-50% by sunrise, which combined with the clear skies and southerly flow are usually indicative of some dense fog developing in those areas. Have added a Limited threat fog graphic for tonight and will monitor trends for any widespread dense fog potential. Then as mentioned, systems to our west will become a concern as we near daybreak tomorrow. A southern stream shortwave trough lifting across East Texas/western Louisiana tonight has been the focus of recent model runs for generating a complex of storms that direction. Latest HRRR and other high-res model guidance indicate an MCS or broken line of storms moving into central LA by mid morning, and possibly another focused area of storm development farther southwest along the line scraping the Gulf Coast later in the morning into afternoon. Regardless of exactly how it evolves, convection moving east overnight will have favorable westerly flow and an instability axis to propagate eastward along, so it seems reasonable that organized strong to severe storms could move into our forecast area tomorrow between mid morning and early afternoon time frame. A bowing line could produce damaging winds, and a tornado could not be ruled out. Therefore a Marginal Risk for severe thunderstorms has been added for northeast LA, southeast AR, and Mississippi from roughly the Greenville/Cleveland areas southeast toward Hattiesburg. Showers and thunderstorms in general will be possible across the forecast area by the afternoon and evening, though organized severe weather is questionable by that time frame. Friday through Wednesday: Details remain tricky for the extended, but big picture forecast is still for several shortwave disturbances moving east across the country to trigger rounds of showers and thunderstorms into early next week. Especially of interest in our area will be the fact that waves will nudge a cold frontal boundary south toward the area, and disturbances are likely to interact with the moist, unstable air mass south of this front. Friday, Saturday, Sunday, and even Monday have some chance for showers and thunderstorms in the forecast area as it stands now. Where it is not raining, afternoon temperatures will push the upper 80s to lower 90s. /NF/ && .AVIATION... (00Z TAFS) Issued at 711 PM CDT Wed May 1 2024 VFR conditions prevail across the region. Areas of IFR to MVFR stratus will develop across parts of south MS & central LA, with patchy dense fog possible in south MS at PIB & HBG. Timing is expected between 02/08-13Z. Any dense fog is expected to diminish by mid-morning, with ceilings rising back to VFR levels. By late morning to afternoon, SHRA & TSRA are expected to spread east across LA & AR then into western MS. Locally heavy downpours may temporarily limit visibilities & ceilings may fall to MVFR levels in some areas. Added some low probs for SHRA at central-western TAF sites of GLH, JAN, HKS & HEZ before the end of the 00Z TAF period. /DL/DC/ && .PRELIMINARY POINT TEMPS/POPS... Jackson 64 84 66 78 / 0 40 50 70 Meridian 62 87 66 83 / 0 10 30 50 Vicksburg 65 82 67 79 / 0 70 50 80 Hattiesburg 64 87 68 82 / 0 20 20 30 Natchez 66 81 66 77 / 0 70 40 70 Greenville 66 83 68 78 / 0 60 80 80 Greenwood 66 85 67 79 / 0 40 70 80 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...None. LA...None. AR...None. && $$ DC/NF/DL
Area Forecast Discussion
National Weather Service Jacksonville FL
900 PM EDT Wed May 1 2024 ...New UPDATE, AVIATION... .UPDATE... Issued at 915 PM EDT Wed May 1 2024 For the latest NE FL and SE GA Daily Key Messages please visit: https://www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf Isolated airmass thunderstorms continue this evening, mainly inland northeast FL and southeast GA, with mean steering winds generally from north to south about 10-15 mph. Boundary interactions and ample instability with MLCAPE of to around 800-1400 J/kg allowed a couple of stronger storms to develop with hail and gusty winds. Current stronger storm is just now about to move south of Marion county. Main updates were to adjust POPs a bit, to expand the slight chances and may need to extend chances further into tonight. Would seem the convection should dissipate all areas by about midnight, but 1 or 2 HRRR model runs suggesting a couple of small showers or a very isolated storm could linger til 1 or even 2 AM tonight. Still anticipate some patchy to areas of fog late tonight and early Thursday morning. && .NEAR TERM... Issued at 244 PM EDT Wed May 1 2024 As the Atlantic and Gulf coast sea-breeze begin to pick up, so will the chances for rain and isolated storms today and into the evening. PWAT values continue to increase from 1.3" to 1.5" bringing ample moisture to the area. Showers will begin to pop up along the Sea-breeze boundaries as they make their way inland, increasing in chances as daytime heating and sea-breezes converge inland. Severe weather is highly unlikely, with no upper level support and dry air aloft. Temperatures will reach into the upper 80s inland, staying in the low to mid 80s along the coast. Overnight lows will be in the low to mid 60s with chances of patchy to widespread fog possible in the early morning hours. && .SHORT TERM... (Thursday through Friday night) Issued at 244 PM EDT Wed May 1 2024 A transition to a slightly stronger east coast sea breeze regime with the best chance of scattered late afternoon showers and maybe a thunderstorm focused toward the I-75 corridor & inland SE GA westward where sea breezes and boundaries merge. Thursday, convection will be more limited than today given a building ridge aloft and even drier PWAT near to just below climo values around 1.1 to 1.2 inches, but enough low level instability will be in place to fuel some updrafts near boundary mergers. By Friday, even drier air with PWAT < 1 inch will focus east of Highway 301 while deeper moisture ahead of an approaching short wave trough will move across our western zones during the afternoon and into the evening which could trigger some late day and overnight convection across SE GA. Winds will gust between 20-25 mph at the coast trailing the east coast sea breeze each afternoon into the early evening. Temperatures will trend near to above normal with highs nearing 90 inland to mid 80s coast under the onshore flow. Low temperatures will range in the 60s. && .LONG TERM... (Saturday through next Wednesday) Issued at 244 PM EDT Wed May 1 2024 Sat & Sun...Elevated rain chances this weekend as a slow moving short wave trough crosses the area and interacts with diurnal instability and mesoscale boundaries. The higher shower and t`storm chances will focus across inland SE GA both days, with more scattered convection across NE FL. The main weather concerns this weekend will be localized heavy rainfall given weak storm motion < 10 kts and above normal PWAT over 1.5 inches. Shear and lapse rate profiles do not favor severe thunderstorm potential. Above normal temperatures in the mid/upper 80s will be tempered by clouds and convection with mild lows in the 60s. Mon through Wed...A warming to HOT trend ensues next week as `stacked` high pressure from the surface to aloft builds across the region, which will limit deep convective growth and thus rain chances despite elevated PWATs. Monday, another passing short wave could trigger some showers mainly across SE GA while low level ridging begins to build across the FL peninsula. Upper ridging amplifies across the eastern Gulf Tue & Wed while the low level ridge axis holds across the FL peninsula. Although a rogue sea breeze shower is not completely unlikely, rain chances will be limited with the main weather story being the near record highs in the low to mid 90s for inland areas by Wed. && .AVIATION... (00Z TAFS) Issued at 915 PM EDT Wed May 1 2024 VFR conditions domiante and looks like some VCSH still warranted near GNV and JAX through about 03z-04z. Some patchy fog expected near VQQ and GNV late tonight. Otherwise, no other significant changes with the TAFs for now. && .MARINE... Issued at 338 AM EDT Wed May 1 2024 Winds will be picking up as surges of onshore winds of 8 to 10 knots from the Atlantic sea breeze shift inland. Slight chance (10%)for isolated showers and storms over the local waters today as the Atlantic sea-breeze pushes its way inland. High pressure ridging dominates the the coastal waters for most of the period with slight chances for showers over the weekend in the afternoon. Rip Currents: High risk of rip currents continue for NE FL beaches today with a moderate risk on Thursday as seas subside. Moderate risk of rip currents continue for SE GA beaches through Thursday. && .PRELIMINARY POINT TEMPS/POPS... AMG 64 90 65 89 / 10 10 0 10 SSI 68 81 67 81 / 10 0 0 10 JAX 66 86 65 86 / 10 10 0 10 SGJ 67 84 67 84 / 10 10 0 10 GNV 64 89 64 89 / 30 30 0 10 OCF 65 90 65 90 / 30 20 0 10 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...High Rip Current Risk until 4 AM EDT Thursday for FLZ124-125-133- 138. GA...None. AM...None. && $$
Area Forecast Discussion
National Weather Service North Platte NE
622 PM CDT Wed May 1 2024 .KEY MESSAGES... - Strong to severe storms across central and southwestern Nebraska late this evening into the early overnight hours. Primary threat is large hail, however, damaging wind gusts (60+ mph) cannot be ruled out. - Brief break from precipitation on Thursday with mild temperatures in the 60s ahead of a second system expected to impact the area on Friday which will bring the potential for strong to severe thunderstorms and locally heavy rainfall. - Dry conditions return Saturday and Sunday. However, unsettled weather conditions continue next week with additional chances for precipitation and a gradual warming trend bringing high temperatures back to near or slightly above normal. The severe threat remains uncertain at this time. && .SYNOPSIS... Issued at 331 PM CDT Wed May 1 2024 Recent GOES-16 WV imagery and RAP 500-mb analysis showed a persistent low pressure system centered across southern Alberta/Saskatchewan with a trough extending southwest into the Great Basin and Desert Southwest. An upper-level shortwave was ejecting off the parent low pressure system, across the Upper Midwest/Great Lakes. A more robust southern stream trough was traversing eastward out of the northern and central Rockies. Southwesterly flow aloft has continued to increase across the central and southwestern Plains. At the surface, high pressure was noted across the Midwest into portions of the northern Plains. Surface low pressure was apparent across the Texas/Oklahoma Panhandle with a dryline extending southwestward into the Upper Rio Grande in Texas and a warm front was tracking northeastward across central Kansas. Isentropic lift on the northwest periphery of the surface high pressure and multiple weak upper-level shortwaves tracking through has resulted in continued scattered light rain showers across north and north central Nebraska. As the surface high pressure tracks northeastward, this activity should exit the area in the next few hours. Some light to moderate rain showers have also developed across the northwest Sandhills this afternoon in vicinity of an inverted surface trough and weak cold front extending across eastern Wyoming into northwest South Dakota. However, the main focus for rain showers and a few thunderstorms this evening into the overnight period will occur as an inverted surface trough extends northeastward out of the southern Plains into the area. As of 3 PM CT, temperatures ranged from 51 degrees at Gordon to 61 degrees at Broken Bow. && .SHORT TERM /THROUGH THURSDAY NIGHT/... Issued at 331 PM CDT Wed May 1 2024 Tonight...Upper-level lift will increase over the area this evening into tonight as the shortwave ejects across the local area. A complex of storms appears to develop in vicinity of the inverted trough across southwest into central Nebraska, primarily after 00Z. This complex of storms will move from west to east across the area, exiting the area by ~09Z tonight as the system tracks northeast into the Midwest region. While the main area for severe weather resides further south and east of the area, continuing to see the potential of a brief window for isolated strong to severe storms across portions of central and southwest Nebraska. Elevated CAPE and steep lapse rates aloft will create an environment that will be supportive of large hail and gusty winds for the cores that are able to maintain themselves. The area of concern will be along and south of a SW-NE line from Chappell to Burwell with the greatest threat across Frontier County where the greatest moisture and forcing will set up. Outside of the severe threat, locally heavy rainfall is possible across portions of the southwest Nebraska into northeastern Nebraska. Some uncertainty remains on the placement of heaviest rainfall due to recent CAMs continuing to waver back and forth. However, anticipate this to occur where the strongest ascent is as the low-level jet (LLJ) noses into the southeastern portion of the state, intersecting the front and MUCAPE >1,000 J/kg. Current thinking is the greatest threat for rainfall amounts of 1 to 2" will reside southeast of a SW-NE line from Hayes Center to Broken Bow to O`Neill. While the threat for flash flooding is low, this will be the area most favorable for heavy rainfall with the possibility of lowland flooding. Thursday and Thursday Night...Outside of the potential for lingering showers and embedded thunderstorms through the early morning hours on Thursday across north central Nebraska, quieter conditions set up across the area during the day. A strong surge of drier air will push into the area behind the exiting system with surface high pressure centering over central Nebraska. West winds will strengthen as a result with frequent gusts of 25 to 30 miles per hour throughout the day. These gusty winds combined with afternoon humidities bottoming out near 20 percent will introduce elevated fire weather concerns for portions of the area, primarily across the Panhandle into the Sandhills (Fire Weather Zones 204 and 210). Unseasonably cool temperatures are expected Thursday, ranging from the upper 50s across northwest Nebraska to upper 60s across southwest. Chilly air will begin to filter in from the northwest overnight with lows ranging from 30 degrees across northwest Nebraska to 40 degrees across southwest. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... Issued at 331 PM CDT Wed May 1 2024 On Friday, the main upper-level low pressure system will finally begin to move northeastward into Ontario with a trough extending into the northern Plains. At the same time, associated surface low pressure will deepen across Ontario with a strong, attendant cold front advancing out of the northwest across the local area through the day on Friday. A modest 250-mb jet maxima of 100+ kts will orient southwest to northeast from southern Wyoming through southern Minnesota, aiding in upper-level divergence. Robust frontogenetical forcing behind the front resulting in increased cloudiness and a threat for precipitation across much of the area Friday and Friday night. While the greatest moisture and instability will reside further south of the area, the robust forcing combined with steep lapse rates will bring create an environment supportive of severe storms capable of producing large hail and damaging winds for areas generally south of Highway 2. Convection appears to initiate off the Front Range, eventually congealing into a Mesoscale Convective System (MCS) as it tracks eastward across southern Nebraska. With the potential for the MCS setup, localized flooding will be a concern with current models highlighting modest QPF of 1"+ across portions of southwest Nebraska. Recent rainfall over the last few days has resulted in saturated ground across much of the aforementioned area which will lead to additional concerns for localized flooding. This is highlighted by the Weather Prediction Center (WPC) Day 3 Marginal Risk of Excessive Rainfall Outlook (ERO) across the southern third of the state of Nebraska. Will continue to monitor the severe potential as CAMs get into range and get a better handle on the track of the low and the environment. As the main system departs eastward early Saturday morning, a return to dry conditions is expected during the day Saturday into Sunday as the upper-level ridge nudges eastward into the Plains. Mild temperatures in the 60s are expected on Saturday, warming into the mid 60s to mid 70s on Sunday. These dry and relatively quiet conditions will be rather short-lived as a strong upper-level low pressure system moving in from the west coast, through the Rockies and into the Plains by the start of next week. This system is very dynamic and may bring a threat for severe thunderstorms to Nebraska on Monday. However timing, location, and degree of the severe threat is uncertain at this time. With the potential for an active period for early next week, make sure to keep up to date with the latest forecasts as details get ironed out with subsequent forecasts. && .AVIATION /00Z TAFS THROUGH 00Z THURSDAY/... Issued at 622 PM CDT Wed May 1 2024 A storm system working across the Great Plains will result in a few aviation weather concerns for western and north central Nebraska terminals through the forecast period. Showers and thunderstorms will continue pushing east across the northern terminals (VTN) early this evening, while new storms will develop across the southern terminals (LBF) later this evening. Erratic gusty winds, reduced visibility, and low ceilings are all expected at times through at least 02/06z. A low stratus deck may work into the region overnight, further lowering cigs into IFR. Southeast winds will transition to west/northwest by mid-morning, which will help clear the clouds out throughout the day tomorrow. Northwest gusts will approach 25 kts. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Viken SHORT TERM...Viken LONG TERM...Viken AVIATION...Snively
Area Forecast Discussion
National Weather Service Midland/Odessa TX
625 PM CDT Wed May 1 2024 ...New AVIATION... .SHORT TERM... (This afternoon through Thursday night) Issued at 1225 PM CDT Wed May 1 2024 WV imagery shows the upper trough moving through SoCal/Baja at 14Z, leaving West Texas and Southeast New Mexico under southwest flow aloft. At the surface, KMAF had a dewpoint of 66F, making it feel like a dry day in Houston. KMAF 12Z RAOB came in w/mucapes in excess of 3500 J/kg, w/a cap that should be eroded completely by 18Z. Mid-lvl lapse rates are ~ 8 C/km, and judging from activity yesterday, this would be expected. The HRRR has been consistent in developing the Pecos supercell ~ 20Z, which should peel off to the east as a right-mover, then unzipping a line of splitting/left- movers northward through the Permian Basin shortly thereafter. While deep-layer environmental shear remains tepid, plenty of cold pools are anticipated which will locally enhance/strengthen cells. KMAF will be doing an 18Z upper air flight, which should show steeper lapse rates as the upper trough approaches. Latest HRRR suggests we may not get off a 00Z flight anyway. Convective activity should continue through late this evening, tapering off to the east by 06Z or shortly thereafter. Abundant boundary layer moisture, clouds, and elevated winds should keep overnight lows 6-8F above normal. Thursday, a cold front will approach the area, but looks to stall just north of the CWA due to diurnal heating. Instead, increased westerlies will shunt the dryline/boundary-layer moisture east. Single-digit RH west of the dryline will result in elevated fire wx conditions. See fire wx discussion below for more details. Thicknesses decrease a little, shaving a couple of degrees off today`s highs, but temperatures should still come in ~ 5-7F above normal. Thursday night looks dry and uneventful and the cold front backdoors into the northeast. Mostly clear skies and the absence of an appreciable LLJ will allow overnight mins to cool to only 3-5F above normal. && .LONG TERM... (Friday through Tuesday) Issued at 1225 PM CDT Wed May 1 2024 The end of this week is expected to be the beginning of a return of more active weather across much of the area. To start the period, a large upper-low is forecast to be positioned over southern Manitoba and Ontario with a shortwave rounding its base across the central Rocky Mountains. Another shortwave trough should be positioned over southern California with southwesterly flow aloft over the southern Great Plains. With the trough passing to the north, a cold front may try to push into northern portions of the region. This front isn`t expected to bring much in terms of cooler temperatures but may result in a few thunderstorms across northeastern portions of the region. Otherwise, temperatures remain warm in the 80s and 90s for the majority with plentiful sunshine. This weekend continues the trend into a more active weather pattern. The southern California trough begins to broaden and lift into the central Great Plains Saturday. This provides an additional push to the cold front from Friday over our northern tier resulting in the front sagging further south until it stalls along the higher terrain. Along and behind this front should be the focus for more widespread thunderstorm development Saturday afternoon through the evening. There may be a threat for a few strong to severe thunderstorms given some modest shear and instability. The more significant threat with these thunderstorms will be very heavy rainfall. PWAT anomalies are expected to range from 0.5"-1" above normal, meaning that there is going to be ample rainfall potential with any thunderstorms. A similar threat for thunderstorms is expected again on Sunday as a stronger shortwave trough digs into the Great Basin. Once again, heavy rainfall is going to be the main concern as another round of thunderstorms is expected during the afternoon and evening for much of the region. Temperatures should be a bit cooler thanks to the cold front and rainfall potential with some 70s returning while the remainder remain in the 80s. The shortwave trough across the Great Basin ejects into the central Great Plains to start the new week. This ushers in the return of drier and warmer weather to the forecast as ridging gradually makes its return to the southern Great Plains. Mostly sunny skies and temperatures in the 80s and 90s once again on Monday with 90s becoming even more widespread by Tuesday and Wednesday to close out the forecast. -Chehak && .AVIATION... (00Z TAFS) Issued at 620 PM CDT Wed May 1 2024 TS is moving away from all TAF sites and are no longer expected to be a threat over the next 24 hours. Southeast winds will shift from the west early behind a cold front. && .FIRE WEATHER... Issued at 1225 PM CDT Wed May 1 2024 A Red Flag Warning remains in effect through early this evening for much of southeast New Mexico and the western higher elevations. This area is where the best overlap of elevated wind speeds and the very dry airmass behind the dryline overlap. It is expected to remain very dry across the western half of the region through the end of this week and into the weekend as it`ll remain behind the dryline with only poor to fair overnight recoveries. Fuels remain very dry across southeast New Mexico and far West Texas due to the lack of rain over the last month or two. This keeps the threat of elevated to near critical fire weather across these areas though relatively weak winds should keep the overall fire weather threat a bit lower. Further to the east, moisture remains relatively high and recent rains keep fire weather concerns low. A potential area of concern is the threat of lightning starts across portions of the higher elevations and adjacent plains. Dry fuels are still present in many of these locations and afternoon thunderstorms are possible today and again Friday and through the weekend. Lightning starts may be possible as a result though overall spread may be limited by weaker wind speeds. Fire weather concerns are expected to ramp up again next week as a strong shortwave trough passes north of the region. This not only expands the critical relative humidity across most the area but increases wind speeds. Given very dry fuels with western extent, the greatest concern is favored across this region with a gradual decrease in fire weather concerns as you move east where recent rainfalls have improved fuels. -Chehak && .PRELIMINARY POINT TEMPS/POPS... Big Spring 62 93 59 87 / 30 0 0 20 Carlsbad 58 89 55 91 / 0 0 0 0 Dryden 67 96 65 92 / 10 0 0 20 Fort Stockton 62 93 59 92 / 10 0 0 10 Guadalupe Pass 57 80 57 82 / 0 0 0 0 Hobbs 56 88 54 87 / 10 0 0 0 Marfa 51 84 48 87 / 0 0 0 0 Midland Intl Airport 62 91 59 89 / 10 0 0 10 Odessa 63 91 59 89 / 10 0 0 10 Wink 59 93 57 93 / 10 0 0 0 && .MAF WATCHES/WARNINGS/ADVISORIES... TX...Red Flag Warning until 11 PM CDT /10 PM MDT/ this evening for Guadalupe Mountains Above 7000 Feet-Guadalupe and Delaware Mountains. NM...Red Flag Warning until 10 PM MDT this evening for Chaves Plains- Eddy Plains-Sacramento Foothills and Guadalupe Mountains. && $$ SHORT TERM...44 LONG TERM....91 AVIATION...10
Area Forecast Discussion
National Weather Service Memphis TN
1026 PM CDT Wed May 1 2024 ...New UPDATE... .UPDATE... Issued at 1011 PM CDT Wed May 1 2024 No significant changes needed to the forecast tonight. No additional rain/thunderstorms are expected until tomorrow afternoon as we warm into the middle 80s once again. Southwest flow will strengthen tomorrow beginning a stretch of numerous days when several weak disturbances will track from the southwest to Northeast across the Middle Mississippi River Valley. Widespread severe storms do not look particularly likely on any day, but a surface low will move across the Memphis area tomorrow night that may enhance a few storms. Stronger storms look most likely along and west of the Mississippi River where dew points will be a few degrees higher and closer to a weak shortwave trough. A cold front will usher in cooler conditions Friday when highs should be in upper 70s. Temperatures will trend warmer each day through the weekend into next week. We should see high temperatures back in the middle 80s by Tuesday. Unsettled conditions will continue well into next week. Expect at least a slight chance of rain and thunderstorms each day. && .SYNOPSIS... Issued at 345 PM CDT Wed May 1 2024 Dry and warm conditions will persist through Thursday afternoon. Thereafter, a cold front will move into the region and bring unsettled weather to the Mid-South through this weekend. Expect highs in the 80s with lows in the 60s. Unsettled weather may persist through the middle of next week. && .DISCUSSION... (This evening through next Tuesday) Issued at 345 PM CDT Wed May 1 2024 Near record high temperatures are being reported across the Mid- South at this hour. Readings are generally in the upper 80s to near 90 degrees. The latest GOES East Visible Imagery reveals a weak MCV swirling over north central Arkansas. An area of showers and thunderstorms has formed on the northeast side of this feature and is lifting NE in southern Missouri. Some outflow from this activity could move into eastern Arkansas and the Missouri Bootheel, but coverage should remain below 20 percent through early evening. Dry conditions will persist overnight as weak upper level ridging remains in place. A southern stream shortwave will traverse the ArkLaTex Region tomorrow morning and lift north into the Lower Mississippi Valley in the afternoon hours. A decaying MCS over the ArkLaTex may reemerge as an MCV tomorrow afternoon and lift northeast into the Mid-South by late afternoon. With up to 1500 J/kg of MLCAPE on hand and enhanced low level vorticity, a few strong to severe storms are possible late tomorrow afternoon and evening. In fact, a few SHARPpy RAP soundings suggest a marginal threat of damaging winds. This activity will likely persist through at least Friday morning. By Friday afternoon, a cold front will approach the region from the west and likely stall near the I-40 corridor. Scattered to numerous showers and thunderstorms will accompany the front. Another reinforcing front will push into the region on Saturday and keep 30 to 40 PoPs over the region as a result. Unsettled weather will likely persist Sunday into early next week as a series of shortwaves translate through the Lower Mississippi Valley. Highs will generally be in the 80s with lows in the 60s. AC3 && .AVIATION... (00Z TAFS) Issued at 642 PM CDT Wed May 1 2024 VFR conditions will prevail through tomorrow afternoon/evening when an MCV moves into the Mid-South. This MCV is expected to result in an extended period of SHRA and possible TSRA persisting through the TAF period. MVFR VIS and CIGS also appear possible with this activity, but confidence is not high enough to include these details in this TAF cycle. && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$ PUBLIC FORECAST...JDS AVIATION...JPR
Area Forecast Discussion
National Weather Service Omaha/Valley NE
602 PM CDT Wed May 1 2024 .KEY MESSAGES... - Storms redevelop today and linger into Thursday, with potential for a few severe storms and flash flooding. The highest severe weather threat will be after midnight and into early Thursday near the Nebraska/Kansas border. - An active weather pattern will continue into the weekend and early next week with the highest chances Friday night and Monday. There will be some severe weather potential at times, but confidence on details is rather low. && .DISCUSSION... Issued at 335 PM CDT Wed May 1 2024 After zipping into the 60s before lunch, increased cloud cover and spotty shower activity has halted the warming of surface temps this afternoon. We remain mostly in the low 60s. 20dBz radar returns pock the entire CWA this afternoon. Still plenty of dry air below 5000 feet, so mostly only traces have been reported but as they and the southern moisture transport saturate the low levels, more measurable rain will be recorded before a temporary reduction in lift and POPs by sunset. Surface analysis shows the surface low and front across central Kansas. The stationary front draped across southeast Kansas this morning is driving north as a warm front. PWAT values are climbing as well. Now close to about 0.6", expect PWAT values to double by about 2AM. CAPE values are scraping the bottom of the barrel this afternoon, but will be spiking overnight with a nose of 1000 J/kg MLCAPE poking into far southeast Nebraska as the LLJ ramps up in the eastern half of the state. Shear values are impressive with sfc winds perpendicular to those at 700 hPa. Elevated storms are a threat with hail being the primary concern overnight. With the broad forcing ahead of the shortwave and its associated WAA and broad forcing, the HRRR has been latching on to an elevated MCS that works west to east through the southern half of the area tonight. Its general shape suggests it`s a wind machine, but successive HRRR runs produce wind gusts below the 60mph severe criteria. Another concern overnight is heavy rain and flooding with PWATs up to 1.5 inches and deep warm cloud layers (3000 feet of clouds warmer than 0C). This gives the system more water content and gives a boost to the coalescence of raindrops. Still, HREF probabilities for 1" rainfall rates have been nearly halved with the 12Z run, likely due to the more progressive nature of the convection forecast overnight. Have opted not to issue a flash flood watch. The OAX hydrologist is on radar duty overnight to monitor flooding potential. Precip should be mostly done by Thursday`s lunch hour as dry air moves in behind the cold front. The severe weather threat for Thursday looks a bit overstated for OAX with better odds south and east of here. .FRIDAY AND BEYOND... Another shortwave sweeps through on Friday night. With a LLJ / cold front interaction, believe an overnight MCS is possible once again brining a threat of severe hail and wind. Chances are probably highest south of here. Surface high pressure builds in over the course of the weekend leading to clear skies and seasonable temperatures. It`ll be a beaut! Mid-70s on Monday will represent the week`s zenith. Monday eve`s severe weather risk may represent the week`s best chance with a negatively tilted trof sweeping through the CONUS`s mid-section. Certainly there are lots of timing / location questions, but with a triple point progged to be somewhere in the area, it may be another day of damaging thunderstorms. && .AVIATION /00Z TAFS THROUGH 00Z FRIDAY/... Issued at 601 PM CDT Wed May 1 2024 Scattered showers are likely to persist this evening with thunderstorm chances increasing overnight at the terminal locations. VFR ceilings will gradually lower to MVFR and then IFR tonight into Thursday morning before improving. East or east-northeast winds of around 12 kt will switch to northwest Thursday with the passage of a front through the area. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ DISCUSSION...Nicolaisen AVIATION...Mead
Area Forecast Discussion
National Weather Service Norman OK
634 PM CDT Wed May 1 2024 ...New AVIATION... .SHORT TERM... (This afternoon through Thursday night) Issued at 129 PM CDT Wed May 1 2024 ***This Afternoon into Tonight*** As a wise man once said: It`s gonna be May. We`re ringing in the traditional most active month of the year with a highly complex forecast for both severe and flooding potential this evening. This morning`s convection has left a rather substantial cold pool with theta-E perturbations on the order of 4-10 Kelvin across central Oklahoma. Recovery is uncertain within our area, but West Texas Mesonet observations show a narrow plume of upper-60s dewpoints gradually advancing northwestward across the eastern Texas panhandle. Currently, the dryline is retreating westward, but with increased diurnal heating it will likely advance back into the eastern panhandle. The third boundary of note in our forecast is what appears to be the synoptic-scale warm front, which meets the dryline at a triple point low near Perryton and extends east-northeast from there toward Medford. Convection initiation appears probable in spite of the intrusion of the cold pool into central Oklahoma. The two likeliest zones for CI are: -Along the outflow boundary in the southeastern TX panhandle -Near the triple point in the northeastern TX panhandle Outflow boundary region: The presence of near-70 dewpoints and 3,000 J/Kg of MLCAPE will encourage thunderstorm development likely by mid afternoon. The initial mode will favor supercells capable of very large hail. Over time, CAMs show a tendency to weaken the 500 mb winds while increasing the LLJ. This will probably encourage supercells to grow upscale into an eastward-propagating squall line. Given the depth of boundary-layer winds and drying in the mid-levels to raise DCAPE to 1,400 J/kg, damaging wind gusts will become a threat toward sunset with a potential in southwest Oklahoma and western north Texas for significant (70+ mph) wind gusts. The tornado threat is conditional, and may be most focused in the spatiotemporal window where the LLJ is increasing directly along the remnant OFB. After sunset, this cluster will continue eastward toward south central Oklahoma, likely weakening over time. A second threat will occur overnight with this cluster - flooding. One-hour flash flood guidance sits as low as 1.6- 2 inches of rain across much of southwest Oklahoma and as low as 1 inch in the Arbuckles. Even a small residence time of storms in this area overnight could trigger recurrence of flooding. Triple point region: Storm coverage is more uncertain here as ongoing stratus/need for further moisture advection cast doubt on reaching convective temperatures. However, CAM guidance (notably the HRRR and MPAS) has become much more bullish in the late morning hours on depicting the development of scattered supercells by late afternoon. The longevity of these storms will be dependent on sufficient theta-E advection to overcome the development of a modest capping inversion after sunset. However, shear profiles will be sufficient for supercellular structures with the potential for large to very large hail. The frontal boundary may also become a focus for tornado potential toward sunset as the LLJ enlarges. CAM guidance is less bullish on the potential for an overnight MCS across north central Oklahoma; thus, it is anticipated that this activity will weaken after sunset. Meister ***Thursday into Thursday Night**** By tomorrow (Thursday) afternoon, a slowly-advancing cold front will be located somewhere in close proximity of I-44. The location of this cold front will likely be affected by tonight`s convection with some spread among guidance. In addition, a dryline will be located in the eastern Texas panhandle or western north Texas. Both of these surface boundaries will be likely focus for convective during the afternoon and evening hours as convective inhibition weakens with daytime heating. Effective bulk shear will be weak to modest at only ~30 knots, so transient supercell structures are possible. Even so, significant hail is possible given the modest cloud layer shear (~50 knots), weak low-level shear, and significant instability (MLCAPE >3000 J/kg). In addition, large downdraft CAPE (>1000 J/kg) may result in damaging wind gusts. The tornado risk is generally low, but if a supercell could constructively interact with the cold front or an outflow boundary, the tornado potential would be higher (especially given the magnitude of instability). Thunderstorms may grow upscale into clusters and move to the southeast late evening into the overnight hours. Flooding will become a hazard, especially for locations that have had recent heavy rainfall. Mahale && .LONG TERM... (Thursday night through next Tuesday) Issued at 300 PM CDT Wed May 1 2024 An active pattern will continue into early next week with periods of showers and thunderstorms as shortwave troughs lift northeast within the west to southwest flow. Currently, it appears the greatest risk of severe weather during this period will be on Monday. Heavy rainfall/flooding will be the primary hazard on the other days. Here are the specific details: Friday: Isolated to scattered daytime thunderstorms are possible as a subtle shortwave trough/PV anomaly moves through in a weakly capped environment. Friday Night into Saturday: A complex of thunderstorms associated with a cold front is expected to move through the area. Heavy rainfall and flooding will be the primary hazard. Sunday: Another shortwave trough is progged to lift into the Southern Plains with a threat for heavy rainfall and flooding. Monday: A negatively-tilted trough is progged to lift into the Plains. Currently, it appears the strongest synoptic-scale ascent and associated surface low will develop across the northern Plains. However, a trailing dryline will likely be located somewhere in the Southern Plains with a moist, unstable air mass with sufficient shear for supercells and severe weather. This is the next potential for significant severe weather if the ingredients come together. Mahale && .AVIATION... (00Z TAFS) Issued at 630 PM CDT Wed May 1 2024 Overall, much of the forecast period tonight and tomorrow morning expected to be MVFR most terminals. Gusty southerly winds will continue through the night. TSRA chances will be highest across southwest Oklahoma and northwest Texas tonight, with possibility for activity to progress eastward across the southern half of Oklahoma overnight into tomorrow morning. Cold front will move into northern Oklahoma toward and after 12Z, with slow progress southward during the day tomorrow. TSRA will be possible along the front late in the forecast period, but will leave out for now due to timing and possibility that cloudiness during the day will limit coverage. && .PRELIMINARY POINT TEMPS/POPS... Oklahoma City OK 64 78 60 77 / 50 70 50 30 Hobart OK 61 79 57 76 / 60 40 40 30 Wichita Falls TX 64 82 61 80 / 70 20 40 20 Gage OK 57 76 50 76 / 30 30 20 30 Ponca City OK 64 76 56 75 / 50 80 40 20 Durant OK 66 79 64 81 / 70 70 60 30 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...Flood Watch through Thursday morning for OKZ035>041-044>046-050. TX...Flood Watch through Thursday morning for TXZ084>090. && $$ SHORT TERM...04 LONG TERM....10 AVIATION...11
Area Forecast Discussion
National Weather Service Reno NV
326 PM PDT Wed May 1 2024 .SYNOPSIS... Cooler daytime temperatures continue today behind the passage of a cold front earlier in the day. Following a brief warmup on Thursday and Friday, temperatures expect to cool down once again over the weekend with chances for valley rain and mountain snow returning along with some stronger winds on Saturday. The latest forecast beyond the weekend going into the beginning of next week calls for a warming trend across the region along with some lower precipitation chances. && .DISCUSSION... At the beginning of the forecast period, the latest RAP analysis shows the CWA currently with a mostly northwesterly flow aloft being west of the axis of an upper air trough this afternoon with ridge trailing the trough over the Pacific Ocean. The current satellite imagery along with surface observations show dry conditions along with mostly light and variable winds with the exception of southern portions of Mineral and Mono Counties as they are experiencing some breezy north-northwesterly winds. Models show the trough moving eastward as the Pacific ridge advances toward the CWA on Thursday. By Friday afternoon, the axis of the upper air ridge is projected to move over the CWA as an upper air low moves into the Pacific Northwest. At the surface, the dry conditions look to continue through the rest of today. While most of the region looks to stay dry on Thursday, northern portions of Washoe County as well eastern Modoc and northern Lassen Counties may see chances for light snow showers in the early morning that transition to light rain as it warms during the afternoon due to a surface low in OR projected to move eastward into ID during the day. Minimal amounts of rain and snow are anticipated with models showing a few hundredths of QPF at most in the locations that see the precipitation. By Thursday evening, these precipitation chances depart to the east with the passing system leaving dry conditions through the remainder of Thursday as well as on Friday. Warmer daytime temperatures compared to today`s are expected on Thursday and especially Friday with models showing a possible warm front beginning to pass through the southern half of NV and northern CA by the late Friday afternoon hours. A good portion of the region may warm up to the middle 60s to the lower 70s during the day on Friday with higher elevations in the Sierra Mountains being slightly cooler. On Friday night, model guidance shows the CWA starting to take a more southwesterly upper air flow as the upper air low moves toward the OR coast. By Saturday afternoon, models are in pretty good agreement with the low moving through onto the OR shore and towards the CWA. On Sunday morning, forecast guidance has the low passing over the northern portion of the CWA before departing to the east in the afternoon causing a northwesterly flow over the CWA for the remainder of the day. With this upper air pattern, models have a surface low in the northeastern CONUS pushing cold front across the region on Saturday. This cold front will allow chances for light rain to move into the northwestern portions of the CWA on Friday night and then spread through the remainder of the CWA during Saturday. Snow levels continue to be near or above 7000 feet on Saturday afternoon. By the evening hours, the snow levels look to drop to around 5000 feet in northeastern CA and around 6000 feet in the Tahoe Basin which will allow for a bit more areas to see the P- type transition to snow. By Sunday morning, the colder temperatures and lower snow levels will allow for most of the area to see light snowfall if precipitation occurs. By Sunday evening, the precipitation chances are anticipated to depart out of the CWA to the northeast. When looking at the NBM snowfall probabilities from Friday night through Sunday, portions of Lassen County have less than a 10% chance of four inches of snow. Higher elevations in the Tahoe Basin as well as Mono and Alpine Counties see a 20-60% probability of four inches of snow. Will continue to monitor this as this may cause hazardous traveling conditions over the weekend for people going through mountain passes with roads becoming slick with some potential slushy snow. As for the latest QPF values for this event, it looks to range between around a tenth of an inch to around a little over an inch in western portions of the region. Another concern during this event is the potential for some stronger southwesterly to west winds with the cold front passage on Saturday afternoon. The latest probabilities of 55 mph wind gusts within the southern half of the CWA ranges between 50-90%. Will monitor this going forward as well in case a high wind product is needed this weekend. Going through the beginning of next week, the northwesterly upper air flow continues with ensemble guidance showing the low opening up into a negatively tilted trough on Monday and Tuesday over the Rocky Mountains. As a result, warmer daytime temperatures are seen to begin the work week with a 10-20% chance for afternoon and evening isolated showers each day mostly for the northern half of the CWA. -078 && .AVIATION... VFR conditions are anticipated across the region at the REV terminals through the remainder of today and going into Thursday. While most terminals may see light and variable winds, KMMH and KMEV see northwesterly winds around 10 kts through around 03-05Z when they begin to decrease. By Thursday afternoon, wind gusts up 25-30 kts are possible for the western NV terminals southward to KMMH while KTVL and KTRK may see gusts up to around 20 kts. A cold front passing through the area is anticipated to produce increased aviation impacts Saturday-Saturday night due to gusty winds with areas of potential LLWS, increased precipitation chances with periods of lower CIGS/reduced VIS, and even some light snow for the Tahoe and Eastern Sierra terminals. -078 && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$