####018006769#### FXUS63 KLOT 030835 AFDLOT Area Forecast Discussion National Weather Service Chicago/Romeoville, IL 335 AM CDT Fri May 3 2024 .KEY MESSAGES... - Increasing chances of showers and thunderstorms capable of producing gusty winds Saturday afternoon and evening. - Periodic shower and thunderstorm chances next week, with some potential for strong to severe storms Tuesday. && .DISCUSSION... Issued at 335 AM CDT Fri May 3 2024 Through Saturday: Ongoing convective activity across portions of northern Illinois and northwest Indiana continues to wane early this morning as remaining instability and associated mid-level lapse rates decrease. In fact, as of 3am CT, very little lightning has been observed in the forecast area over the past hour. While a few lightning strikes are still possible through sunrise, a departing mid-level wave will limit remaining deeper-layer support. Meanwhile, a cold front roughly parallel to the Mississippi River will continue to shift a band of shallow showers across the area into mid-morning. High pressure will quickly settle across the western Great Lakes through tonight. The combination of a rather dry airmass evident by upstream dew points generally in the 30s along with fairly clear skies today should allow seasonably warm conditions in the 60s along the shore and lower 70s inland today. Today's cold front will stall across the south half of Illinois, allowing for a return of low-level moisture behind the surface high on Saturday. A small mid-level wave lifting northeast across the far Upper Mississippi River Valley Saturday morning may brush the northwest CWA. Return of sufficient moisture by this point remains in question, though an isolated storm cannot be ruled out for areas west of I-39 late morning into early afternoon. A disjointed trough passage into the western Great Lakes later Saturday and into Saturday night should better align with increasing shallow moisture to produce scattered showers and storms as far east as around I-57 by sunset. However, fairly shallow low-level moisture return and a deep reservoir of dry mid-level air may limit storm coverage but also support gusty winds with any convection. Kluber Saturday Night through Thursday: Showers and thunderstorms should be ongoing along and ahead of a cold front Saturday evening. Some of these storms could be strong to severe early in the evening, with mainly localized gusty winds, though this threat should diminish with eastward extent due to diurnal loss of low-level instability and generally weak deep-layer shear. Sunday through Sunday night looks to be largely dry and cooler, as Saturday night's cold front settles toward the Ohio Valley and surface high pressure builds east across the upper Midwest and western Great Lakes region. Temperatures will be limited to the lower 70s well inland Sunday afternoon, while northeast winds off of Lake Michigan will keep highs only in the upper 50s near the lake. Lows will dip into the mid-upper 40s in most spots Sunday night. Ensemble guidance depicts deep upper level trough developing across the western and central CONUS heading into next week, with a closed upper low developing across the Northern Plains Monday. A series of mid-level short waves are progged to rotate around the south and southeast periphery of the circulation as it slowly drifts east, eventually lifting the front across the lower Ohio Valley northward as a warm front later Monday night into Tuesday. Some spotty elevated showers are possible as early as Monday afternoon and evening as warm/moist advection develops atop the warm frontal slope, though really becomes more focused into the local area Tuesday into Tuesday night. This appears to be the period with the greatest potential for thunderstorms, some potentially strong to severe given strong mid-level wind fields and warm/moist/conditionally unstable low levels. Temperatures looks to surge back into the upper 70s/around 80 Tuesday afternoon, with surface dew points rising into the 60s as the warm front lifts across the area. Periodic shower and thunderstorm chances linger through the mid-week period, as ensembles continue to indicate the upper trough drifting east across the upper Midwest/Great Lakes region through the end of the forecast period. Blended NBM guidance maintains chance pops both Wednesday and Thursday, especially during the more diurnally-favored afternoon/evening hours. Higher low-level Theta-E air mass gradually gets shunted east of the area during this time, with temperatures gradually settling into the lower 70s by Thursday. Ratzer && .AVIATION /06Z TAFS THROUGH 12Z SATURDAY/... Issued at 1220 AM CDT Fri May 3 2024 Aviation Key Messages: - SHRA persist through pre-dawn hours. Embedded TSRA threat diminishing but non-zero, especially toward KGYY. - Period of MVFR ceilings develops pre-dawn and lingers until a cold front passes after sunrise. - Winds shift NNW with cold front after sunrise, then turn NNE- NE by mid-morning. NE winds persist through remainder of period. Somewhat diffuse area of low pressure was lifting north- northeast across eastern WI as of midnight, with a cold front trailing through far western IL into western MO. This low was associated with a mid-level disturbance over central IL, and will continue to lift northeast with the cold front moving across the terminals by sunrise. SHRA and embedded TSRA will persist ahead of the front, with TSRA growing more isolated with time, with greatest coverage of TS likely toward KGYY. MVFR ceilings along the cold frontal zone will spread across the terminals pre-dawn, eventually scattering out to VFR by mid- morning. Winds, while somewhat disorganized by earlier stronger convection, will be generally light W-SW ahead of the cold front, then shift NNW behind the front by sunrise. Winds will then continue to veer northeast by mid morning behind the front, and will generally remain northeast through the day. Winds turn light easterly Friday evening, and there is some model guidance indication that MVFR stratus may form east of the area across Lake Michigan and IN, which could drift west into the terminals later in the night. Confidence is low this far out, but have included a FEW020 mention in TAFs. Ratzer && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...None. && $$ Visit us at weather.gov/chicago ####018010940#### FXUS64 KMAF 030836 AFDMAF Area Forecast Discussion National Weather Service Midland/Odessa TX 336 AM CDT Fri May 3 2024 ...New SHORT TERM, LONG TERM, FIRE WEATHER... .SHORT TERM... (Today through Saturday afternoon) Issued at 333 AM CDT Fri May 3 2024 An active period is ahead for the short term, with severe thunderstorms possible both today and Saturday. Early this morning, winds are generally light and variable, thanks to a combination of a weak cold front sagging across the Permian Basin and the retreating dryline. Dewpoints across the Permian Basin and into Lea County have recovered into the 50s and even lower 60s, with lows not expected to drop much below where they area now, in the upper 50s to upper 60s for many. Expansive low clouds have already worked their way northwestward into portions of the Lower Trans Pecos, and are progged to expand across the central and eastern Permian Basin through daybreak. However, clearing skies are expected by mid-morning, allowing for plenty of time for warming and subsequent destabilization ahead of convective development this afternoon. As southwesterly winds develop this afternoon, the dryline will mix eastward from its morning position west of the Pecos River, and sharpen up from the Permian Basin southward across the Trans Pecos to the Rio Grande. The aforementioned cold front this morning will wash out, mixing northward this afternoon as southerly flow increases across the eastern half of the forecast area. Highs today top out in the middle 80s to lower 90s for most, with 100s along the Rio Grande in the Big Bend. Given elevated moisture to the east of the dryline, diurnal destabilization will result in CAPE values in excess of 2500-3000 J/kg (and possibly up to nearly 4000 J/kg). Lapse rates around 8 degC/km will support large to very large hail, with veering flow and increasing low- level shear through the late afternoon and early evening lending to a non-zero tornado threat. Initiation is progged to occur over the Permian Basin and Trans Pecos south toward the Rio Grande by mid-afternoon, with storms generally moving eastward and gradually congealing into outflow-dominated clusters by the evening. A bulk of the activity should be east of our area by mid-evening, though a few lingering non-severe storms may be possible over northern portions of the area overnight as the dryline retreats, in closer proximity to the diffuse frontal boundary. The low-level jet will keep winds and moisture elevated tonight, allowing the dryline to once again retreat to the higher terrain of Southeast New Mexico and Southwest Texas. In a change from today, convective initiation is expected earlier in the day on Saturday as the aforementioned front surges southward coincident with a surface trough that develops immediately to the lee of the higher terrain. Thus, precipitation chances as well as potential for strong to severe storms encompass much of the area, with particular focus across the Permian Basin and Trans Pecos where the greatest potential (40%-70%) for severe storms exists along the eastward moving dryline and southward moving cold front. Shear will be notably stronger on Saturday, around 35-45kt, and moderate to strong instability will yield mainly an initial supercellular storm mode, with very large hail and damaging winds the primary concerns, along with locally heavy rainfall given precipitable water values increasing to 1 to 2 standard deviations above normal by late afternoon and early evening, per NAEFS ensemble data. Storms are progged to linger into the evening, and aside from the storm potential, the cold front will also yield cooler temperatures, with afternoon highs in the 80s to lower 90s along and south/west of the Pecos (hotter along the Rio Grande), with 70s encroaching over the northern tier of the forecast area where the front will arrive prior to peak heating. JP && .LONG TERM... (Saturday night through Thursday) Issued at 333 AM CDT Fri May 3 2024 Rain chances will continue Saturday evening into Sunday afternoon before tapering off as the southern stream short wave trough and upper low move east of the area by then. Potential for strong to severe storms continues Saturday night for eastern portions of the area, with the threat for flooding rains, damaging winds, and large hail. Widespread clouds and rain chances Saturday night will keep lows mild and slightly above normal in the 60s for most aside from 50s in higher elevations and northern portions of the SE NM plains. Highest rainfall amounts are likely east of the Pecos River, especially east of the Midland-Odessa area over the eastern Permian Basin and Western Low Rolling Plains, where maximum rainfall totals at the end of this rain event are forecast to range from 1.00 to 2.00 inches. As the upper low responsible for this weekend's rain moves east and takes on a negative tilt as it moves into the central Great Plains, increasing quasi-zonal flow will push the dryline that has been present over much of the central Permian Basin the past few days well to the east of the area. Accompanying this dryline passage beginning Monday afternoon will be increasing southwesterly winds, clearer skies, and a warming trend Monday into Thursday as subtle mid-level ridging also builds in. No rain is expected for the rest of the long term until at least Friday. A cold front will move in from the north Thursday, with cooler temperatures expected to close out next week. Highs will be below normal Sunday due to lingering cloud and rain chances, with widespread low to mid 80s and 90s confined to parts of the Trans Pecos and Rio Grande valleys. Monday through Thursday will see highs above normal with widespread upper 80s and 90s, and reaching triple digit readings near the Rio Grande. Highs Friday will be near to below average following the passage of a cold front, with mainly 80s and higher readings in the 90s confined to the Trans Pecos, Terrell County, and along the Rio Grande in the valleys. Lows will be above normal for early May throughout the long term with widespread 60s, aside from 50s in higher elevations and northern portions of the SE NM plains and Permian Basin, each night from Saturday night into Thursday night. Lows Friday night will be closer to normal and feature 50s for most places north and east of the Pecos River, most of the SE NM plains and higher elevations across West Texas, and 60s elsewhere. && .AVIATION... (06Z TAFS) Issued at 1218 AM CDT Fri May 3 2024 A weak cold front is sagging southward into the area, while the dryline is starting to retreat westward, resulting in some fairly variable winds. Sustained speeds tonight are expected to remain under 12kt, with winds expected to settle out of the E/SE by morning. Winds will shift to the S/SE, becoming gusty during the afternoon, with gusts sticking around into the evening for MAF/INK/FST where the low-level jet will come into play. MVFR ceilings are progged to develop into the area late tonight, though have only included mention at MAF where confidence is highest. VFR conditions will return to MAF by around 14Z, with VFR conditions otherwise prevailing. Thunderstorms are possible, mainly during the 21Z-02Z time frame for MAF/FST, but will defer to later issuances for potential TS mention. && .FIRE WEATHER... Issued at 311 AM CDT Fri May 3 2024 ERCs 90th percentile or higher over most of Eddy County and southwest of the Pecos River will result in critically dry fuels fuels. This afternoon, RFTIs of 3-5 present from Sacramento Foothills into Chaves, Eddy, and Lea Counties in Southeast New Mexico into the Guadalupe Mountains and eastern Culberson County, along with min RH from 6 to 10 percent and highs 5 to 8 degrees above normal for this time of year in the upper 80s and lower 90s, have prompted a Rangeland Fire Danger Statement to be issued for these regions from this afternoon through this evening. Rain east of the Pecos River and lack of gusty winds likely constrain fire weather risk Saturday into Sunday. However, fire weather risk increases again Monday afternoon and continues into next Thursday as near zero rain chances are present for much of the area, dewpoints decrease over much of the area, widespread min critical RH develops each afternoon Monday into Thursday, and gusty southwesterly winds develop over much of the SE NM plains into the mountains and western Permian Basin in West Texas each afternoon from Monday into Thursday. This will all contribute to widespread RFTIs in the 3-6 range west and southwest of the Pecos River Monday, Tuesday, Wednesday, and Thursday afternoons. In addition to all of this, highs and lows 5 to 10 degrees above normal and mainly in the 90s and 60s, respectively, as well as poor overnight recovery over much of the area from Monday into Thursday morning, will dry out fuels even more. Depending on extent and amount of rainfall today into Sunday, eastward extent of fire weather risk is still uncertain at this time. Still, near critical fire weather conditions are likely today and this weekend over southwesternmost Eddy County and West Texas, and critical fire weather conditions Monday into Thursday next week expected over the SE NM plains, much of the area southwest of the Pecos River and west of a line from Gaines County into central Pecos County into western Terrell County, each afternoon from Monday into Thursday. Behind a cold front moving in from the north at the end of next week, increased dewpoints, better overnight recovery Friday morning, and decreasing eastward extent of min critical RH all yield a decrease in fire risk for the end of next week. && .PRELIMINARY POINT TEMPS/POPS... Big Spring 88 63 79 60 / 40 40 80 80 Carlsbad 92 60 84 58 / 0 10 20 50 Dryden 92 68 85 67 / 20 10 30 50 Fort Stockton 92 66 89 63 / 30 20 50 60 Guadalupe Pass 83 59 79 57 / 0 0 10 30 Hobbs 89 59 79 56 / 10 10 50 60 Marfa 87 54 89 52 / 10 0 20 30 Midland Intl Airport 90 63 81 60 / 30 30 60 80 Odessa 90 64 82 62 / 30 30 60 80 Wink 93 66 87 62 / 10 10 40 60 && .MAF WATCHES/WARNINGS/ADVISORIES... TX...None. NM...None. && $$ SHORT TERM...84 LONG TERM....94 AVIATION...84 ####018005924#### FXUS64 KSJT 030837 AFDSJT Area Forecast Discussion National Weather Service San Angelo TX 337 AM CDT Fri May 3 2024 ...New SHORT TERM, LONG TERM... .SHORT TERM... (Today and tonight) Issued at 336 AM CDT Fri May 3 2024 ...Severe weather expected again this afternoon and evening... Even with the showers and thunderstorms we've seen over the past few days, moisture is still plentiful across the area. Low clouds are already overspreading much of the area early this morning and should stay in place through the mid/late morning before mixing out. As the boundary layer warms through the day, we will see large scale destabilization across the area. With dew points ranging from the mid 60s to lower 70s, MLCAPE values by early afternoon will be on the order of 3000-4000 J/kg. Similar to the past few days, shear is still going to be on the more marginal side, especially in the low to mid levels around 30-35 kts. Storms are expected to initiate off of the dryline which should be in the vicinity of the Permian Basin by mid afternoon. Storms will likely go up quickly should remain discrete initially. Very large hail will be the main threat with the initial development along with a subsequent damaging wind threat. While the tornado threat is generally on the low side thanks to weak low level flow, we will have to watch boundary and storm scale interactions as these may be able to enhance local conditions and make tornadic development more favorable (similar to what we saw yesterday). Storms are expected to grow upscale with time, likely becoming a more linear feature where a transition to more of a wind threat is expected. Though, given the favorable thermodynamic profiles, large hail will still remain possible through the duration of the storms lifecycle. These storms will be efficient rainfall producers as noted by Pwat values over 1.25 for nearly the entire area. Though the storms should be moving fast enough to limit flash flood potential, many of our northern and eastern counties are already decently saturated thanks to rain events over the past week or 2 so it won't take much to potentially create some problems. High temperatures today will range from the lower 80s across the Big Country and Heartland, locations that will remain socked in cloud cover for longer, to the lower 90s in the Concho Valley and along the I-10 corridor. Clouds will rebuild across the area tonight, behind the storms, keeping low temperatures mild in the 60s. && .LONG TERM... (Saturday through Thursday) Issued at 336 AM CDT Fri May 3 2024 Severe weather and heavy rainfall will continue to be the main issued through the weekend, ahead of unusually hot conditions for next week. Air mass remains very unstable for Saturday ahead of a weak cold front and a shortwave trough approaching from the west. Most models depict fairly widespread thunderstorm initiation by Saturday afternoon across the Permian Basin and South Plains and then quickly rolling into West Central Texas late in the afternoon and into the evening hours. Widespread convection may end up decreasing the severe threat, but increasing the heavy rainfall threat. Right now, appears the greatest severe threat will be across the Concho Valley west into the Permian Basin and Trans Pecos ahead of the front and in an area that may see a little more sun before the storms develop. By Sunday, multiple rounds of convection may begin to take its toll on the air mass and make it a little harder to destabilize. Widespread convection once again though with the remnants of the frontal boundary draped across the area. Highs may still in the upper 70s and lower 80s across the area. Rainfall totals for Saturday and Sunday will begin to add up, and portions of the area will see very heavy rainfall. Where is the question, and does the heavy rainfall occur on areas that have already seen some decent totals over the last week. No Flash Flood Watch at this point, but after we see where todays convection ends up, we may need to consider something. Main upper level trough pushes across the Southern Plains by Monday afternoon, leaving a ridge aloft to set up across the area. Latest model blends are showing mid to upper 90s by Wednesday and Thursday as dry and hot pattern prevails. && .AVIATION... (06Z TAFS) Issued at 1242 AM CDT Fri May 3 2024 VFR to MVFR ceilings are currently present across the area. Low-end MVFR to IFR stratus is expected to overspread the area in the coming hours, impacting all terminals through the remainder of the overnight hours and continuing until mid/late morning. Ceilings should lift back to VFR between 16-18Z with clearing from southwest to northeast. Some degradations in visibility will be possible, especially at KBBD and KJCT through 12Z. Winds out of the southeast will increase tomorrow afternoon and may become gusty to around 20 kts at some sites. Showers and thunderstorms will again be possible during the afternoon and evening hours but due to uncertainty in overall coverage, have left a mention of VCTS. Upgrades to prevailing groups in future updates will likely be needed as hi-res guidance continues to come in. && .PRELIMINARY POINT TEMPS/POPS... Abilene 83 62 80 61 / 30 40 70 90 San Angelo 90 64 85 63 / 30 30 60 80 Junction 92 67 87 65 / 20 20 30 70 Brownwood 83 66 81 63 / 20 30 60 80 Sweetwater 84 62 79 61 / 40 50 80 90 Ozona 89 65 84 63 / 30 30 40 70 Brady 84 65 81 63 / 20 30 50 80 && .SJT WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...50 LONG TERM....07 AVIATION...50 ####018006204#### FXCA62 TJSJ 030839 AFDSJU Area Forecast Discussion National Weather Service San Juan PR 439 AM AST Fri May 3 2024 .SYNOPSIS... A Flash Flood Watch is in effect for all Puerto Rico and the U.S. Virgin Islands. Unstable conditions (due to an upper-level trough approaching the area from the west and an induced surface trough), increasing moisture, and lighter winds will promote periods of showers and thunderstorms across the local islands, particularly today through Saturday. The precipitable water content is forecast to remain at normal to above normal levels through the long term period, with a drying trend late next week. && .SHORT TERM...Today through Sunday... During the overnight hours, the eastern half of Puerto Rico experienced some rainfall and thunderstorm activity. The highest accumulations were observed in municipalities like Humacao, Naguabo, and Yabucoa, with around 1 to 4 inches of rain. Fajardo, Luquillo, and Ceiba also experienced rainfall rates of around 1 to 3 inches, where Flood Advisories were issued. The island of St. Croix also experienced some rainfall, but accumulations were not significant. Overall, the eastern sections of Puerto Rico had an active night, while the western sections experienced calm weather conditions. Minimum temperatures were in the 70s to low 80s across coastal areas and the upper 60s to low 70s across the mountainous areas. The short-term forecast remains on track. An upper-level trough and an induced surface trough will promote wet and unstable conditions throughout the weekend, particularly today and Saturday. Tropical moisture from the Caribbean will also move into the area, increasing the chances for widespread rainfall and flooding through this weekend. Showers and thunderstorms continue to be the dominating weather features through at least Sunday, particularly along the eastern half of Puerto Rico and the U.S. Virgin Islands. By the end of the workweek into the weekend, an upper-level maxima will move across the islands with winds around 70 knots. The Precipitable Water (PWAT) model guidance shows values in the 75th percentile or above normal climatological levels through the weekend. The 500 mb temperatures also suggest values around -8 degrees Celsius, meaning that there is an increase in the potential for some isolated thunderstorm activity across Puerto Rico and the U.S. Virgin Islands. As saturated soils prevail, any brief period of heavy showers or persistent light rainfall could lead to urban and small- stream flooding,  localized flash flooding, and mudslides, particularly across the interior, the eastern half of Puerto Rico, and the U.S. Virgin Islands. A Flood Watch was issued through Sunday afternoon. We encourage citizens and visitors to be aware of any additional updates in the forecast. .LONG TERM...Monday through Friday... Wet and unstable conditions should continue through midweek next week. If the rainfall forecast materializes during the short- term period, any additional shower activity over saturated soils will further enhance the potential for flash flooding and mudslides. Residents and visitors are encouraged to monitor the evolution of the weather conditions over the long-term period. A surface high pressure is expected to build over the western Atlantic during the first part of the week. This will promote moderate winds from the east to northeast through the end of the workweek. In addition, the remnants of the previous surface trough to our north or just across the northeastern Caribbean are expected to merge with a frontal boundary across the central Atlantic and linger over the local area through at least Thursday. At upper levels, another trough will pass mainly to our north from Tuesday through Thursday, maintaining unstable conditions across the islands. The highest precipitable water (PWAT) values are expected during this period, with global guidance suggesting 2.00-2.25 inches of PWAT. Daily rainfall amounts could range between 1 and 3 inches, with the highest accumulations in diurnal activity over portions of eastern, central, and western PR. More stable conditions are forecast for Friday as a mid-to-upper level ridge over the western Caribbean extends into the local area, bringing drier air aloft and causing the PWAT to drop to around 1.50 inches. && .AVIATION... (06z) TAFS VRB weather conditions are fcst to persist throughout the period. Expect VCTS to develop after 03/14Z at TJSJ/TIST/TISX and after 03/18Z at TJBQ/TJPS causing tempo MVFR to brief IFR conds. ESE winds at 04-16 kt with higher gusts near heaviest showers. && .MARINE... A surface high pressure extending from the western to central Atlantic will promote light to moderate trade winds across the regional waters. Seas should remain between 2 and 5 feet during the next few days, with the highest seas expected across the offshore waters. An induced surface trough to our north will yield lighter east to east- southeast winds and promote shower and thunderstorm development across the area through early next week. && .BEACH FORECAST... Fading swell and lighter winds will promote mainly a low to moderate risk of rip currents during the next several days. However, flooding rains and thunderstorms are expected through the weekend across the islands. && .HYDROLOGY... A Flash Flood Watch remains in effect for all of PR and the USVI from this morning through Sunday afternoon. Rainfall totals between 3 and 6 inches and locally higher are possible through the weekend. Please refer to the latest Flash Flood Watch (FFASJU) for more information. && .SJU WATCHES/WARNINGS/ADVISORIES... PR...Flood Watch through Sunday afternoon for PRZ001>013. VI...Flood Watch through Sunday afternoon for VIZ001-002. AM...None. && $$ SHORT TERM...MMC LONG TERM....DS AVIATION...MMC