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
168 FXUS64 KEWX 090605 AFDEWX Area Forecast Discussion National Weather Service Austin/San Antonio TX 105 AM CDT Thu May 9 2024 ...New AVIATION... .UPDATE... Issued at 818 PM CDT Wed May 8 2024 The capping inversion proved just too hard to break to allow for deep convection this afternoon into this evening. A couple of showers near Lake Buchanan and a shower north of Fredericksburg fizzled out earlier. A shower over Lampasas County will be of no impact to our area. With the capping only getting stronger with sunset, no additional development is expected. As a result, will cancel the Tornado Watch and remove POPs for our northeastern areas for this evening. Have re-established trends to the temperatures, dewpoints, and winds for the remainder of tonight into early morning. There remains a much better chance of showers and thunderstorms for Thursday afternoon near the intersection of a dryline and cold front over the Hill Country. Then, steering flow will take them across I-35 corridor northeast of San Antonio to the US 77 corridor during the late afternoon into evening when they will dissipate with loss of heating. Forecast soundings show strong to extreme instability with MLCAPE of 3,500+ J/kg and steep mid level lapse rates of 8.5 C/km, and high 0-6 km shear of 50 KTs. A few strong to severe storms are expected during the afternoon into early evening. Large, possibly very large hail (2 to 3 inches) and damaging wind gusts up to 70 mph are the main threats, however cannot rule out a tornado or two. && .SHORT TERM... (Tonight through Thursday night) Issued at 145 PM CDT Wed May 8 2024 Low cloud cover continues across much of the eastern two-thirds of the area with clearing out west. With the clearing out west Del Rio is already at 93 degrees at 1 pm. For locations outside of the Rio Grande Plains, temperatures are in the 80s. Highs later today will range from the lower to middle 90s with 100-103 degrees temps out west and this should be near record high values for Del Rio. A weak boundary was seen on radar earlier today and has become somewhat stationary in the Hill Country. As temperatures rise into the 90s later today we could see an isolated storm develop near this boundary across mainly the northern counties by 5 pm or so. Would not expect the storms too last too long, and die off somewhat quickly with the loss of day time heating. There is another conditional threat of severe weather with this activity as the environment is favorable for severe storms with large hail being the main risk. Overall PoPs are low but will mention the threat of isolated storms with a 10 PoP for the northern counties through 7 pm. Most of the tonight period will be quiet with warm temperatures once again. Lows will be back in the upper 60s to upper 70s. There will also be additional low clouds and patchy fog across much of the area. Another hot day is expected tomorrow with highs back in the lower 90s to 105 degrees. Del Rio should fall just below record values tomorrow. A weak boundary will approach the area by the early afternoon hours and high-res and global guidance is consistent on showing development of some scattered strong to severe storms for areas mainly north of a Fredericksburg to New Braunfels to Halletsville line. Large hail and damaging winds would be the main threats with this activity. There is a level 3 out of 5 (enhanced) risk of severe storms with this activity. Much of this activity will be over by 9 pm with the remainder of the night period rain free. Lows will be in the middle 60s to lower 70s. && .LONG TERM... (Friday through Wednesday) Issued at 145 PM CDT Wed May 8 2024 Post-frontal temperatures cool off from the ongoing well above average conditions from Friday into this upcoming weekend with northeasterly to easterly surface winds. A cutoff low across the Desert Southwest will help to maintain a southwesterly flow aloft over the region. An occasional ripple of some weak upper level energy may be embedded within the flow at times. This may help to spark some convection across the terrain of Mexico that could attempt to move into our western zones, mainly close to the Rio Grande, Friday evening and again Saturday evening. Saturday will have the slightly better odds compared to Friday for activity advancing past the river. Rain and storm chances become highest Sunday through Monday, including across interior portions of the region, as the upper level low gets closer and supplies better forcing to the region. While temperatures will help to limit instability compared to recent days, it does remain sufficient and with enough shear where some strong storms could be possible. Additionally, locally heavy rain may be possible, especially for locations that see multiple or training storms. Medium range guidance does indicate greater uncertainty given differences on timing and location of the upper level low. A warmer and more humid southerly flow regime returns by early to middle of next week. Rain and storm chances will be expected to lower behind the exiting upper level low but is not completely eliminated. Low to very low end chances become more conditional pending the capping inversion with any minor forcing as higher instability will again pool over the region with the warmer afternoon temperatures. && .AVIATION... (06Z TAFS) Issued at 1248 AM CDT Thu May 9 2024 Low clouds continue to develop and spread northward through the I-35 corridor. Cigs should drop quickly over the next few hours and based on the latest data, we have included some TEMPO groups in the 10-15Z time frame for low end IFR and will have to monitor for some VLIFR conditions in both cigs and vsbys. Conditions will be slow to improve through this morning, but a return to VFR is still anticipated this afternoon. We will keep the Prob30 group for TSRA as convection initially develops over the Hill Country and moves east and southeast as a cold front advances from the north. Out west at DRT, VFR remains in place for the next few hours, but low clouds should move in around 09Z bringing low end MVFR cigs through 14Z. The dryline will move through mid-morning bringing a quick return to VFR. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 92 69 82 65 / 30 10 10 10 Austin Bergstrom Intl Airport 92 68 82 65 / 30 10 10 10 New Braunfels Muni Airport 94 70 84 67 / 20 10 10 10 Burnet Muni Airport 88 66 79 63 / 40 10 10 10 Del Rio Intl Airport 105 72 89 72 / 0 10 30 30 Georgetown Muni Airport 90 66 80 63 / 40 20 10 10 Hondo Muni Airport 100 71 86 69 / 0 0 10 10 San Marcos Muni Airport 93 69 83 65 / 20 10 10 10 La Grange - Fayette Regional 90 71 84 67 / 20 10 10 10 San Antonio Intl Airport 98 71 84 68 / 10 10 10 10 Stinson Muni Airport 99 73 85 70 / 10 0 10 10 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Short-Term...Platt Long-Term...MMM Aviation...Platt