Sunrise 6:35 AM   Sunset 8:18 PM Moonrise 10:27 AM   Moonset 12:13 AM

  Print   HELP   Reset   Save   Recall  New

FXUS64 KEWX 130739 AFDEWX

Area Forecast Discussion National Weather Service Austin/San Antonio TX 239 AM CDT Mon May 13 2024

New SHORT TERM, LONG TERM

SHORT TERM
(Today through Tuesday)
Issued at 210 AM CDT Mon May 13 2024

...Severe thunderstorms possible late Monday morning through Monday evening mainly along and east of the I-35 corridor with large to very large hail, and strong damaging winds as the primary hazards...

Severe thunderstorms with large to very large hail and damaging winds are looking increasingly likely today as a cold front slides southeastward into South Central Texas. A 500mb shortwave trough with an associated 50-60 kt jet streak over North Central Texas will place our region within the right entrance region. In combination with extreme instability of 2500-4500 J/kg, steep mid-level lapse rates of 7.5-8.5 C/km, and 0-6km bulk shear of 45-55 kts, severe storms are expected to erupt along a cold front as it pushes south and eastward late this morning through the early afternoon. The latest WV imagery shows the shortwave mentioned above over eastern New Mexico as it rounds the base of a trough lifting out over the Cornbelt. The cold front was located over west/southwest Texas and should rapidly push eastward through the overnight hours.

The latest SPC Day 1 Forecast places much of the I-35/I-37 Corridor and all of the Coastal Plains within a Level 3 of 5 (Enhanced Risk)
for severe storms with large to very large hail driving the upgrade from a Level 2 (Slight Risk). The entire Hill Country, generally along and east of a Kerrville to Uvalde to Carrizo Springs line, is in a Level 2 of 5 Risk for this today as well. CAMs have been all over the place over the last 24 hours, but have started to come in line on a solution, especially from the HRRR: Storms developing over the Southern Edwards Plateau or the Highway 90 Corridor and sliding east-northeast ahead of the front, then southeastward as the front pushes through the region from northwest to southeast in the afternoon hours. Some guidance, like the 00Z RRFS, indicate storms will initially develop ahead of the front, followed by additional storm development along the front as it moves into the area in the afternoon and early evening hours. The best bet would likely be some sort of mix of the two, with perhaps a discrete storm or two tapping into that extreme instability ahead of the boundary late Monday morning or early afternoon, with the potential for additional development further north over the Hill Country and sliding southeast with the cold front by the late afternoon and early evening hours.

Storms should push out of the entire CWA by 03Z Tuesday, with quiet weather expected into the day on Tuesday. Temperatures are expected to warm a bit more as cloud cover shouldn't be as hard to break on Tuesday with 500mb shortwave ridging taking hold for the day. Highs will range from the upper 90s over the Rio Grande Plains to the upper 80s over the eastern zones. Sunny skies and drier air with dewpoints ranging from the 50s to mid 60s will make it fell relatively comfortable despite highs warming back to around average for mid-May.

LONG TERM
(Tuesday night through Sunday)
Issued at 210 AM CDT Mon May 13 2024

The mid-week system has slowed down slightly associated with another trough over the west coast that will shift east during the ladder half of the week. Precipitation chances begin Wednesday night and continue through Thursday night. Still some uncertainty in how any potential showers or thunderstorms develop over the area, with likely not all of South Central Texas seeing rain during this time.
The better chances for severe weather look to be Thursday with limited instability forecast Wednesday evening. PWATS generally range from about 1.5-2 inches which will bring the concern for heavy rain. There is still some potential the more widespread development of convection will be northeast of the area, especially on Thursday.

Some low end precipitation chances are seen Friday as some models are slow to exit the trough out of the area while others bring some weak upper level ridging over the area. If the front stalls, precipitation chances may linger into Saturday. For now, only have 15-20% PoPs on Saturday, but would monitor for changes in the upcoming days. Warmer temperatures are forecast Sunday and early next week with forecast highs in the 90s and low triple digits.

AVIATION
(06Z TAFS)
Issued at 1216 AM CDT Mon May 13 2024

Another night, another round of tricky TAFs. The latest hi res guidance has not been our friend and timing thunderstorms over the operational period is a low confidence forecast. At present, greatest threat appears to be at SAT and SSF, so have opted to go with TEMPO groups between late morning and early afternoon Monday, while at AUS, a PROB30 group was utilized late morning through mid-afternoon. As far as ceilings go, LIFR is expected at AUS with IFR ceilings looking likely over the next couple hours at SAT and SSF. VFR ceilings are unlikely to return again until after the frontal passage Monday afternoon. Winds should turn to move of a 310-350 direction late Monday followed by VFR ceilings by 00Z at all sites.

PRELIMINARY POINT TEMPS/POPS
Austin Camp Mabry 85 66 89 67 / 50 10 0 0 Austin Bergstrom Intl Airport 85 63 89 64 / 50 10 0 0 New Braunfels Muni Airport 87 64 91 65 / 60 10 0 0 Burnet Muni Airport 84 64 87 65 / 20 0 0 0 Del Rio Intl Airport 99 69 100 73 / 10 0 0 0 Georgetown Muni Airport 85 62 87 64 / 30 10 0 0 Hondo Muni Airport 91 64 94 66 / 50 10 0 0 San Marcos Muni Airport 86 62 90 64 / 60 10 0 0 La Grange - Fayette Regional 85 65 87 64 / 50 20 0 0 San Antonio Intl Airport 88 65 92 67 / 60 10 0 0 Stinson Muni Airport 90 67 93 67 / 60 10 0 0

EWX WATCHES/WARNINGS/ADVISORIES
None.

Full Color Weather Map

Link to Loop


Other links: GEOS-West     Contential US     Full GOES-East

Central Texas,