Area Forecast Discussion
Issued by NWS Austin/San Antonio, TX
Issued by NWS Austin/San Antonio, TX
633 FXUS64 KEWX 111744 AFDEWX Area Forecast Discussion National Weather Service Austin/San Antonio TX 1144 AM CST Thu Dec 11 2025 ...New SHORT TERM, LONG TERM, AVIATION... .KEY MESSAGES... - Up and down temperatures over the next seven days, including a cold front Sunday. - Locally dense fog possible for the Coastal Plains to I-35 corridor Friday morning. - Low to medium chances (20 to 40 percent) of rain for the Coastal Plains Saturday and for the Rio Grande Sunday, with drier conditions elsewhere for the next seven days. && .SHORT TERM... (Tonight through Friday night) Issued at 1141 AM CST Thu Dec 11 2025 Southerly winds at the surface have made their return this afternoon in response to high pressure shifting east. Dry conditions still prevail across South-Central Texas this afternoon, but that should start to change tonight as the south winds reel in a plume of moisture from the Gulf. Dew points should rise steadily starting this evening and will make for more mild overnight temperatures in the 40s and 50s tonight, with the most noticeable increases in moisture over the Coastal Plains and I-35 corridor. Modeled hydrolapses are favorable for advection fog developing mainly after midnight and especially close to sunrise over the Coastal Plains to I-35 corridor and Winter Garden region, so we`ll be monitoring for the possibility of patchy to areal fog Friday morning. A 20 to 30 percent of dense fog is also depicted in the latest blended guidance with higher explicit probabilities from the HREF and REFS ensembles. Fog and low stratus should break Friday morning, but there is some uncertainty over whether the cloudmass fully disperses or if it sticks around into Friday afternoon. With a lobe of warm air aloft drifting into the area from the northwest on Friday, areas in the clear should see an abnormally warm mid-December day with highs in the mid to upper 70s. If a low cloud deck sticks around, temperatures could stay in the 60s Friday afternoon in localized spots. Chances of this occurring are higher in the San Antonio area and east of I-35 where southerly flow runs up against the Balcones Escarpment. A weak baroclinic trough Friday night may help maintain lows in the 40s over the Hill Country and Southern Edwards Plateau, but moist Gulf air will likely keep lows mild in the mid 50s to around 60 along and east of I-35 Friday night to Saturday morning. && .LONG TERM... (Saturday through next Thursday) Issued at 1141 AM CST Thu Dec 11 2025 Continued southerly winds and broad isentropic lift supports some increased cloud cover Saturday primarily over the eastern half of the area with low chances (20 percent) for isolated showers. Those clouds may help reduce temperatures slightly by a few degrees compared to Friday, but overall an unseasonably warm day remains forecast. Timing remains on track for a cold front arriving from the north Saturday night into Sunday. Lack of mid-level moisture and synoptic- scale forcing should limit the extent of rain ahead and along the front, but there could be sufficient moisture and instability along the Rio Grande for some showers and an isolated thunderstorm during the day Sunday. However, chances are only 20 to 40 percent. Breezy northeast winds should develop behind the front throughout Sunday. The front will bring about a cooler Sunday and Monday, with a possible light freeZe over the northern half of the CWA Monday morning before southerly winds return and a warming trend commences heading into midweek. An upper-level shortwave trough looks to approach the region from the Intermountain West on Tuesday, which could bring a shot of rain. However, those chances are very uncertain given uncertainties over the trough`s trajectory into the area. Moving forward, a zonal pattern aloft with anomalous ridging over the Southern Plains is depicted across essentially all ensemble guidance towards the end of next week. This strongly favors a warm pattern, and accordingly, the latest outlook from the Climate Prediction Center shows an 80 to 90 percent chance of anomalous warmth in the week leading up to Christmas. && .AVIATION... (18Z TAFS) Issued at 1141 AM CST Thu Dec 11 2025 VFR conditions are forecast for the local area terminals through late tonight. Return flow is forecast to dominate through tonight and then becoming light and variable, however, the wind flow looks to stay from the southwest over the I-35 Corridor sites. Increased moisture across the local area translates to fog development across the Coastal Plains late this evening and spreading to the north overnight into Friday morning. Patchy to areas to widespread fog is forecast to affect the Coastal Plains overnight through Friday morning with reduced visibilities anticipated for areas along the I- 35 Corridor including the Austin and San Antonio airports. At this time, hires models and ensemble guidance are in good agreement on developing fog overnight with different visibility restrictions from a few miles to less than one mile to the south and east of I-35 Corridor. Have introduced 2 miles visibility (IFR conditions) in addition to IFR cigs for KSAT and KSSF for the 12Z Friday time frame. For KAUS, the fog situation is more complicated and we will continue to adjust it as new data comes in for future aviation forecast packages. Low cigs and visibilities lift late Friday morning for the return of VFR conditions. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 49 73 56 73 / 0 0 0 10 Austin Bergstrom Intl Airport 46 72 56 73 / 0 0 10 10 New Braunfels Muni Airport 47 72 57 73 / 0 0 10 10 Burnet Muni Airport 46 74 51 70 / 0 0 0 0 Del Rio Intl Airport 46 78 50 76 / 0 0 0 0 Georgetown Muni Airport 47 75 53 72 / 0 0 0 0 Hondo Muni Airport 45 72 54 77 / 0 0 0 0 San Marcos Muni Airport 47 71 57 74 / 0 0 10 10 La Grange - Fayette Regional 50 71 59 76 / 0 0 10 20 San Antonio Intl Airport 49 72 59 76 / 0 0 0 10 Stinson Muni Airport 50 72 60 77 / 0 0 0 10 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Tran LONG TERM....Tran AVIATION...17