Severe weather season will be kicking off in Texas during the next 36 hours, courtesy of a powerful storm ejecting from the Desert Southwest. The are of low pressure will draw very warm and moist air (unstable, with lifted indices around -6 to -8) northward from the Gulf of Mexico, while potent upper dynamics join convergent cold and dry air masses over the Lone Star State. A surface warm front is expected to take shape close to the Gulf Coast and the Interstate 10 corridor during the afternoon hours on Wednesday, and intense convection taking shape across the Edwards Plateau and central Rio Grande Valley is expected to "ride" this frontal structure like a railroad train track through San Antonio, Austin, Waco and Fort Worth through a Victoria....Houston....Lufkin....Tyler arc during the wee hours of Thursday. With the core of the 500MB vorticity pegged to move through after sunrise, a scenario exists where we could see additional development of thunderstorms with hail and strong winds. Then things settle down in the afternoon of February 22.
But for how long? While I see no major issues arising from a weak disturbance aloft moving out of Mexico Thursday night and Friday (a few showers possible), we have two systems of far greater intensity to deal with early next week and around February 28. Saturday looks pretty nice, with mild temperatures and abundant sunshine. But incoming energy and falling barometric pressures from the Desert Southwest will deliver yet another storm and frontal structure Sunday night and Monday. This feature may be a bit slower than the current storm, resulting in bigger rainfall amounts and two or three rounds of convection.
The "big show", however, comes to town as February gives way to March. Exact timing is still a bit uncertain, but the ensemble formats of the major forecast models seem insistent on developing a monster-sized storm in West Texas, which then moves toward northern Georgia, then to the Virginia Capes and on toward Sable Island below Nova Scotia. For Houston, the general "read" I get from this threat is one of heavy rain and severe thunderstorms. Further north and east, however, this feature looks to have a "winter storm" character with snow and ice potential followed by colder weather. If a blocking signature over Hudson Bay and Quebec verifies, a very stormy day in SE TX on February 28 will be followed by about four days worth of unseasonably cold air. We need to watch this system, as do folks in the Old South, Midwest, Appalachia and the Eastern Seaboard for a variety of inclement conditions in the February 28 - March 3 time frame.
Wednesday: Cloudy, windy and mild with showers likely in the afternoon. Highs 64 Freeport to 68 Security
Wednesday Night: Cloudy, windy and mild with showers and thunderstorms. Some thunderstorms may approach severe limits. Lows 56 Cut And Shoot to 60 Brazoria
Thursday: Showers and thunderstorms, heavy at times, ending by noon. Then clearing and mild. Highs 70 Conroe to 74 East Columbia
Thursday Night: Mostly cloudy and cooler. Lows 50 Panorama Village to 54 West Columbia
Friday: Mostly cloudy with a few showers likely during the morning. Highs 62 Dobbin to 66 Guy
Saturday: Mostly sunny and mild. High 70, Low 48
Sunday: Increasing cloudiness, becoming windy with showers and thunderstorms in the afternoon and night. High 71, Low 52
Monday: Showers and thunderstorms. High 77, Low 59