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
593 FXUS64 KEWX 031704 AFDEWX Area Forecast Discussion National Weather Service Austin/San Antonio TX 1204 PM CDT Mon Jun 3 2024 ...New AVIATION... .SHORT TERM... (Today through Tuesday) Issued at 245 AM CDT Mon Jun 3 2024 Increasingly dangerous heat is now becoming the primary weather story within the short term but there will still remain a lingering low end chance (20%) for convection later this afternoon and into this evening across the region. The HREF CAM members are generally indicating two possible areas for activity. The first area is across the Rio Grande Plains down into the CRP CWA while the second would focus from mainly the Hill Country northward into Central Texas across the SJT/FWD CWAs. Several of the members do indicate that a convective complex could evolve across the FWD CWA. If this does evolve, it could help advance outflow southward into the region after dark and may act as a catalyst itself for a few showers or a storm or two as well. Instability and shear is enough across the region to where a strong to severe storm may be possible. If a strong to severe storm is able to develop, damaging winds and large hail would be the primary hazards. Most locations will not receive rain or storms and should remain under partly to mostly cloudy sky. Latest model guidance continues to favor an even drier forecast on Tuesday where rain chances trend around or below 10 percent area wide. Now let`s return to that heat. Afternoon highs will be expected to climb into the mid to upper 90s across most locations while areas along and near the Rio Grande peak at or above 100 degrees. With elevated dew points in the upper 60s to the mid 70s persisting through the afternoon, heat indices are expected to reach up into the 104 to 112 degree range this afternoon across most locations outside from the Hill Country. Highest heat indices concentrate across the Rio Grande Plains, which has prompted a Heat Advisory across those locations from 1 PM through 7 PM CDT. From Val Verde county into the I-35 corridor and the coastal plains, a Special Weather Statement was issued through 7 PM CDT as result of these heat indices today. Tuesday looks to trend slightly hotter across the region where ambient temperatures trend up to a few degrees warmer than this afternoon. This likely will lead to an areal expansion of the Heat Advisory for Tuesday as most locations will see heat indices peak slightly higher in comparison of today`s forecast heat indices. Those spending an extended amount of time outdoors and not acclimated to the heat are susceptible to heat related illness, if not taking the proper heat precautions. Heat Precautions: Never leave people and/or pets alone within a closed car, stay hydrated with plenty of water, wear loose-fitting and light colored clothing, and take frequent breaks within the shade and air conditioning. && .LONG TERM... (Tuesday night through Sunday) Issued at 245 AM CDT Mon Jun 3 2024 Mid level ridging shifts toward our area on Wednesday, then centers nearby Thursday into Friday. All models indicate hotter conditions for this time frame. However, there remains some uncertainty on exactly how hot and how much the dewpoints mix with heating. Regarding the models, the GFS is the hottest and driest while the ECMWF and CMC are less hot and more moist. Regarding the ambient conditions, recent rains have saturated the soils mainly across the Hill Country to along and east of I-35 where amounts greater than 1 inch have occurred. It will take time to dry these soils keeping dewpoints elevated in those areas due to inefficient evapotranspiration. Meanwhile, across the Rio Grande Plains and Winter Garden areas, rainfall has been much less, averaging less than 1/10 inch. It must be noted that there were heavier rains up to 2 inches across portions of the Winter Garden and nearby Rio Grande a few days ago, however their impact is much less now with a few days of drying there. Thus, with drier soils, dewpoints should mix more efficiently and in turn causing the hottest temperatures there. Have gone with dewpoints lower than NBM across those areas. Taking all this into account, parts of our area will likely reach Heat Advisory levels on Wednesday, and possibly Thursday, especially areas where the dewpoints are slower to mix. It also is possible to have a small Excessive Heat Warning area on Wednesday. Subsidence underneath the ridge should provide strong convective inhibition. However, cannot rule out a strong thunderstorm or two where temperature/dewpoint discontinuity sets up due to strong heating especially late Wednesday afternoon into early evening due to the ridging not established yet. The GFS maintains ridging, though slightly weaker, through next weekend while the ECMWF and CMC move it away from our area. Expect the afternoon heat to drop below Advisory levels. A drier airmass will keep rain chances out of the forecast. && .AVIATION... (18Z TAFS) Issued at 1201 PM CDT Mon Jun 3 2024 Cloud cover is holding on, but is in the process of lifting into VFR categories. Should see VFR continue for the remainder of the afternoon and evening hours. Another round of MVFR is expected tonight as low-level moisture continues to be in place. Most locations will remain rain free, but there is an outside shot of a shower or thunderstorm impacting AUS this evening. Overall probabilities were too low to mention in the TAFs. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 93 77 96 77 / 10 20 10 10 Austin Bergstrom Intl Airport 93 77 96 77 / 10 20 10 10 New Braunfels Muni Airport 96 77 98 77 / 10 10 10 10 Burnet Muni Airport 91 74 93 75 / 20 20 10 10 Del Rio Intl Airport 103 79 106 81 / 10 10 0 0 Georgetown Muni Airport 92 75 96 76 / 20 20 10 10 Hondo Muni Airport 97 77 99 76 / 10 10 10 10 San Marcos Muni Airport 94 77 97 76 / 10 10 10 10 La Grange - Fayette Regional 92 78 94 77 / 10 10 10 10 San Antonio Intl Airport 96 78 98 77 / 10 10 10 10 Stinson Muni Airport 98 78 99 78 / 0 10 10 10 && .EWX WATCHES/WARNINGS/ADVISORIES... Heat Advisory until 7 PM CDT this evening for Atascosa-Dimmit-Frio- Maverick-Zavala. && $$ Short-Term...Brady Long-Term...04 Aviation...29