Area Forecast Discussion

KEY MESSAGES

- Soggy Monday likely for most and for the eastern two-thirds of the area again on Tuesday.

- Cool weather continues into Tuesday with near normal temperatures Wednesday and a warming trend for late week.

SHORT TERM

(Today through Tuesday) Issued at 1229 AM CDT Mon Apr 20 2026

Showers and isolated thunderstorms are currently ongoing across the area at this hour with activity expected to continue and increase in coverage as the main disturbance responsible slowly shifts eastward. At the same time, the upper-level ridging responsible for keeping our northern and eastern CWA areas dry is moving off to the east. This will result in additional overrunning and development of widespread showers continuing into daybreak this morning. Most activity is expected to remain fairly light. However, the atmosphere is very moist and as such the HREF PMM 24 hour QPF is still showing a wide swath of 1-2 inches for our area. So any heavier cells could certainly take advantage of this as there remains some instability aloft. Temperatures look to stay fairly cool for this time of year as many areas remain locked under showers and thick cloud cover with areas remaining in the 50s and perhaps mid 60s. Another round of rain showers along with isolated thunderstorms looks set to impact the eastern two thirds of our area heading into Tuesday with rain cool air and CAA once again helping to limit afternoon high temperatures with most barely hitting 70 degrees. Main exception would be for those under a developing shortwave ridge out west. As a result, areas across the Rio Grande plains can expect to see highs in the mid to upper 70s.

LONG TERM

(Tuesday night through Sunday) Issued at 1229 AM CDT Mon Apr 20 2026

Tuesday night we should see rain chances decrease somewhat before a second wave of energy moves back into the area helping to kick off more showers and isolated storms with our overrunning/isentropic lift type pattern continuing into early Wednesday. We finally start to dry out by Wednesday afternoon with areas along and east of I-35 continuing to see the highest rain chances. All activity should finish by Wednesday night as most precipitation finally pushes off to the east and out of our area. Thursday and Friday should be a much drier days as southerly low level flow returns and with it the possibility for some isolated streamer showers over the Coastal plains on Friday. Temps should warm up nicely back into the mid 80s on thursday and into the upper 80s by Friday. Our quieter and drier weather is short lived as a trough out west begins to deepen helping to bring us back into southwest flow. As a result, thunderstorms appear possible for both Saturday and Sunday given the setup in place.

AVIATION

(06Z TAFS) Issued at 1229 AM CDT Mon Apr 20 2026

Overrunning rain showers will moisten up the lower levels and lower ceilings in the San Antonio area within the next hour or two. Will keep with prior issued TAF timing on lowering into MVFR as this is, along with the blended guidance, a bit more aggressive than the MOS guidances. Del Rio and San Antonio airports will drop into IFR before daybreak, given that model data shows areas of precipitation most of the night. At AUS, only intermittent light rain is expected to begin around midnight, so it may take longer for the ceiling to lower. By daybreak, all areas have a chance to lower into IFR.

PRELIMINARY POINT TEMPS/POPS

EWX WATCHES / WARNINGS / ADVISORIES

None.