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
226 FXUS64 KEWX 261653 AFDEWX Area Forecast Discussion National Weather Service Austin/San Antonio TX 1153 AM CDT Sat Oct 26 2024 ...New AVIATION... .SHORT TERM... (Today through Sunday) Issued at 222 AM CDT Sat Oct 26 2024 A weak surface front stalls across portions of the Hill Country entering today. The pressure gradient has relaxed as a result of this boundary and will result in very light winds over the region through today, with variable/shifting directions. Some slightly drier dew points are forecast to reach near the I-35 corridor as well. The muggiest dew points above 65 degrees are located to the east of the I-35 corridor into the coastal plains. This will be where any fog and very low stratus is favored to develop this morning and again into Sunday morning. Latest model probabilities are showing a stronger signal of dense fog across our southeastern row or two of counties this morning in comparison to yesterday morning. Any regions of fog and low stratus should erode by late morning today and Sunday. Mid-level clouds may be a little more prevalent today from the afternoon into the evening, otherwise expect for mostly sunny skies to trend. Well above average temperatures and a continued lack of rainfall will remain the rest of the story for South-Central Texas as mid- level ridging will remain in control and centered over the Baja California peninsula to our west. The light to modest south to southeasterly flow resumes Sunday as our nearby front lifts/fizzles out and surface high pressure builds more into the Southeastern CONUS and the northeastern Gulf of Mexico. The afternoon highs continue to top out from the mid to upper 80s to the low 90s and will challenge the daily record highs at the climate sites. The overnight lows range from the upper 50s to near 60 in the Hill Country to the upper 60s and near 70 degrees across the coastal plains. && .LONG TERM... (Sunday night through Friday) Issued at 222 AM CDT Sat Oct 26 2024 The subtropical ridge axis will initially be centered over northwestern Mexico early next week. Subsidence associated with this area of high pressure will keep our weather dry along with above normal high temperatures for the early portion of next week. The subtropical ridge axis is expected to be nudged eastward by an upper level trough axis as we head through Tuesday. The center of the subtropical high is expected to be centered over the southeastern U.S. by early Wednesday. Meanwhile, surface low pressure develops over eastern Colorado into the central plains states leading to a tightening pressure gradient. As a result, gusty south winds develop across all of south central Texas on Tuesday into Wednesday. The surface pressure gradient will be disrupted Wednesday night into early Thursday as a cold front drops southward into the northern half of Texas. The latest round of the medium range models are showing some better agreement with regard to the southward movement of the front and manage to show the front moving into the Hill Country to near Austin Thursday afternoon. The front may continue to slowly sag southward Thursday night, but with the center of the surface high behind the front staying well to our north, the front may struggle to reach the coastal plains by Friday morning. We do expect a slight cooling trend to develop on Thursday into Thursday night as the front sags southward. However, temperatures behind the front will still remain above normal for this time of year. With quasi-zonal flow over the Rockies emerging on Friday, lee-side surface troughing quickly develops, leading to a return of south to southeasterly surface winds over our region by late Friday. As for rain chances during the mid to late week period, we will keep a low chance in the forecast for locations along and east of a Llano to New Braunfels to Cuero line on Wednesday given southwest flow aloft and an upper jet moving in from the west. Upper dynamics don`t look overly impressive on Thursday, but with some weak forcing along the front, we`ll keep a 20-40% chance of rain for all areas, except out west along the Rio Grande. With an upper trough axis well to our west, southwesterly flow aloft remains intact on Friday. We will keep a low chance (mainly 20-30%) for rain in the forecast, which is a little below the NBM numbers. && .AVIATION... (18Z TAFS) Issued at 1151 AM CDT Sat Oct 26 2024 Mostly clear skies are expected through tonight with light and variable surface winds around 5 knots or less. Low stratus and areas of fog are expected again late tonight into Sunday morning; however, models favor locations just east of the I-35 terminals, namely SAT and SSF. Have continued to only mention SCT low ceilings at these locations but will need to monitor trends the next few updates for how far west the stratus will make it. DRT will remain VFR through the period. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 91 67 91 64 / 0 0 0 0 Austin Bergstrom Intl Airport 91 64 91 62 / 0 0 0 0 New Braunfels Muni Airport 91 66 91 63 / 0 0 0 0 Burnet Muni Airport 87 64 89 63 / 0 0 0 0 Del Rio Intl Airport 90 65 92 64 / 0 0 0 0 Georgetown Muni Airport 89 63 90 63 / 0 0 0 0 Hondo Muni Airport 90 63 90 61 / 0 0 0 0 San Marcos Muni Airport 91 64 90 61 / 0 0 0 0 La Grange - Fayette Regional 91 66 91 62 / 0 0 0 0 San Antonio Intl Airport 90 67 90 65 / 0 0 0 0 Stinson Muni Airport 92 67 91 65 / 0 0 0 0 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Short-Term...Brady Long-Term...Platt Aviation...27