312 FXUS64 KEWX 172332 AFDEWX Area Forecast Discussion National Weather Service Austin/San Antonio TX 532 PM CST Fri Jan 17 2025 ...New AVIATION... .SHORT TERM... (Tonight through Saturday night) Issued at 209 PM CST Fri Jan 17 2025 Key Messages... - Cold front arrives tonight bringing cooler temperatures for Saturday. - Widespread hard freeze is expected Saturday night over the Hill Country with temperatures falling into the 20s. A weak upper level shortwave has managed to squeeze out some showers across the region this afternoon. Little to no accumulation is expected from this, as we`ve mainly noted trace amounts at locations that have observed rain. This disturbance has also been a bit more expansive with regard to cloud cover than earlier guidance had indicated, so we`ve opted to lower highs today for most locations. It will still be FAR warmer than we are going to see temperatures for at least the next week, so enjoy those 60s. Our long-advertised cold front is currently situated over the northern Texas Panhandle. This front will make rapid progress southward this afternoon and evening, arriving in the Hill Country and Southern Edwards Plateau between midnight and 3am and moving through the remainder of South Central Texas by 9am Saturday. Highs will likely be reached in the morning over the Hill Country and northern I-35 Corridor with locations south and west warming into the 60s and perhaps lower 70s over the southern Rio Grande Plains. The really cold push of air arrives as an arctic front and secondary push of air arrives Saturday night with temperatures plummeting into the 20s and 30s. The short term forecast is dry but the long term is a different story. For more on that, scroll below. && .LONG TERM... (Sunday through Friday) Issued at 209 PM CST Fri Jan 17 2025 Key Messages: -Hazardous cold occurring early to midweek with very high confidence (80-100%) in hard freezes each night from Sunday night through Wednesday Morning. -Be prepared to protect People, Pets, Plants, and Pipes from the cold weather. -Increasing chances for winter precipitation from Monday evening through Tuesday morning but low confidence on total accumulation amounts. At least minor travel impacts expected. -Warming up Wednesday, but monitoring another system towards late week. The arctic air will be in place as the period starts on Sunday morning with area temperatures ranging from the mid 20s across the Hill Country to the upper 20s and low 30s elsewhere across South- Central Texas. Factoring in breezy northerly flow with winds around 15 to 25 mph, and higher gusts, wind chills will range anywhere from 10-15 degrees across the Hill Country to 15-25 degrees elsewhere. This may necessitate a Cold Weather Advisory for a portion of the region. Mostly sunny conditions are then expected through the rest of the day on Sunday, allowing for temperatures to climb into the 40s for most locations, and around 50 along the Rio Grande. A widespread hard freeze is expected Sunday night through Monday morning, with lows in the teens across the Hill Country and low to mid 20s for most other locations. While wind speeds will weaken slightly Sunday night into Monday morning, Cold Weather Advisories and possibly an Extreme Cold Warning could be needed as wind chill values range from the single digits to the teens. In addition to the very cold temperatures, MLK JR Day should start off with mostly sunny skies but the cloud cover steadily increases in response to the approaching weather system, which we`ll go into more detail about down below. This cloud cover and increasing moisture will help to cap afternoon highs in the 30s/lower 40s on Monday. While differences are still noted within the latest medium range guidance, the solutions have narrowed regarding the 500 mb pattern with the amplification of the shortwave diving south-southeastward from the Pacific Northwest and the location/strength of the coastal low/trough off South Texas. The GFS and the GEFS members over the past 18 to 24 hours have trended toward a slower, more amplified, and colder/wetter solution than the past runs. While the GFS/GEFS is still running a tad warmer compared to the ECMWF/EPS and especially the CMC/GEPS, it`s certainly much closer than what prior runs of the GFS/GEFS had indicated. This continued trend has necessitated a farther nudge upwards into the medium chance (40-60%) category for precipitation from the I-35 corridor eastward into the coastal plains. If the recent model trends continue to hold, then PoPs will likely need to be increased even more. Initially, around and soon after the onset of this event, a mixed precipitation type event may take place near and south of the I-10 and US HWY 90 corridor Monday evening, with modeled sounding profiles, indicating a weak warm nose aloft. North of this region, the precipitation should mainly be snow. Forecast soundings show the column cooling with time across southern areas overnight and through Tuesday morning with the predominate precipitation type changing to snow. The precipitation chances are expected to decrease by Tuesday afternoon across the region as the base of the trough swings through and then moves east of the area. While both snow and ice accumulation is looking possible across portions of the region (30-50% from I-35 eastward for at least half an inch of snow), it remains difficult to pin down the total amounts this far out. Additionally, the snow to liquid ratios and shapes could also become quite tricky, especially as there is the concern for a very dry layer at least initially, at the more favorable dendrite growth zone. Again, like the previous discussion had pointed out, the deterministic runs of the GFS and ECMWF total snow is on the higher end of it`s ensembles. In addition, more fluctuations in the models are likely, which is why we are showing a gradual increase upward in PoPs rather than a larger jump. It should also be stressed to exercise extreme caution when viewing snow or freezing rain accumulations from any one model or certain apps this far out. Probabilistic guidance from the Winter Storm Severity Index continues to show a modest increase in probabilities for minor to moderate impacts across portions of the region. Some clearing does look to take place from west to east Tuesday afternoon, but it might be too late for central and eastern areas to have a big impact on temperatures, especially if there is any snow on the ground. We have held high temperatures in the mid to upper 30s for central and eastern areas Tuesday afternoon and low 40s immediately along the Rio Grande. Monday night into Tuesday morning and again Tuesday night into Wednesday morning will continue with hazardous cold weather with Cold Weather Advisories or even possibly Extreme Cold Warnings in effect as the overnight lows fall into the teens and 20s with colder wind chills ranging from the single digits to the teens. Southerly flow finally resumes during the day on Wednesday, with highs rebounding into the mid 40s to near 50 degrees along the Rio Grande. There is very low confidence in Thursday and Friday`s forecast, as there remains considerable timing differences on the next upper level trough, associated cold front, and a coastal low. The deterministic GFS and CMC guidance is leaning dry but the GEFS/GEPS ensemble mean does have some light QPF in our eastern most areas. The 12Z ECMWF run came in rather wet but the EPS mean remains on the lighter side. We will keep precipitation chances in the slight chance (20%) range. We`ll have to again monitor the surface temperatures closely but we`ll get to those details as we get closer in time. && .AVIATION... (00Z TAFS) Issued at 522 PM CST Fri Jan 17 2025 The main story for this forecast period will be the strong FROPA expected tonight. Model guidance and forecast soundings indicate some rare LLWS developing around or shortly before midnight and continuing for a few hours before subsiding after 9-12Z. Winds are expected to shift to the west or west-northwest late this evening and then northerly after sunrise on Saturday. Up to 40-50 kts of wind shear look likely at about 2000 ft at AUS, SAT, and DRT, generally out of the west or west-northwest. Once the front moves through wind shear is expected to subside. However, northerly winds will remain and become quite gusty at all sites. The timing of these gusty winds is expected to start around 16Z for all sites except KDRT where the front is expected to move through slightly earlier with gusty winds expected around 13Z. Expect VFR ceilings to continue throughout the forecast period for all sites. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 45 56 29 42 / 0 0 0 0 Austin Bergstrom Intl Airport 45 57 29 42 / 0 0 0 0 New Braunfels Muni Airport 46 61 31 44 / 10 0 0 0 Burnet Muni Airport 41 54 27 40 / 0 0 0 0 Del Rio Intl Airport 49 68 34 47 / 0 0 0 0 Georgetown Muni Airport 42 54 27 39 / 0 0 0 0 Hondo Muni Airport 46 65 31 47 / 10 0 0 0 San Marcos Muni Airport 44 59 29 42 / 10 0 0 0 La Grange - Fayette Regional 46 57 29 42 / 0 0 0 0 San Antonio Intl Airport 48 62 32 44 / 10 0 0 0 Stinson Muni Airport 49 63 33 46 / 10 0 0 0 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Short-Term...MMM Long-Term...Brady Aviation...CJM
No recent Short Term Forecast (NOW) has been issued for NWS Austin/San Antonio CWA (EWX).
No recent Special Weather Statement (SPS) has been issued for NWS Austin/San Antonio CWA (EWX).