Area Forecast Discussion
Issued by NWS Austin/San Antonio, TX
Issued by NWS Austin/San Antonio, TX
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
285 FXUS64 KEWX 020546 AAA AFDEWX Area Forecast Discussion...UPDATED National Weather Service Austin/San Antonio TX 1246 AM CDT Thu May 2 2024 ...New AVIATION... .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. && .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... (06Z TAFS) Issued at 1224 AM CDT Thu May 2 2024 A complex of strong to severe thunderstorms are moving across the Hill Country while pushing to the northeast. Some activity at the tail end of this feature could clip KAUS within the next hour or two. Therefore, included a TEMPO group with -TSRA for KAUS. In addition, low cigs at IFR category are forecast overnight into the middle of the morning for KAUS. Similar situation apply for KSAT and KSSF where IFR cigs are expected to prevail overnight through at least 18Z Thursday. MVFR cigs return sometime in the mid to late afternoon. KDRT sits at MVFR but around dawn lowering to IFR. MVFR cigs return late morning with cigs lifting to VFR by 17Z. Southeasterly flow 5 to 10 knots are forecast to prevail through the forecast period. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 83 71 86 71 / 50 20 20 20 Austin Bergstrom Intl Airport 83 71 85 70 / 60 20 20 20 New Braunfels Muni Airport 85 72 87 71 / 40 10 20 10 Burnet Muni Airport 82 70 84 69 / 30 20 20 20 Del Rio Intl Airport 96 76 97 74 / 10 0 30 20 Georgetown Muni Airport 82 71 84 70 / 50 20 20 20 Hondo Muni Airport 85 70 89 70 / 10 10 20 10 San Marcos Muni Airport 84 71 86 69 / 50 10 20 20 La Grange - Fayette Regional 84 73 85 72 / 60 20 20 10 San Antonio Intl Airport 84 72 87 72 / 20 10 20 20 Stinson Muni Airport 86 73 89 72 / 20 10 20 10 && .EWX WATCHES/WARNINGS/ADVISORIES... Flood Watch until 7 AM CDT this morning 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...17 Long-Term...18 Aviation...17