Discussion
The thunderstorms that swept through southeastern Texas are indicative of the type of pattern we will find ourselves involved in during the next 10 days or so. If you think that you see a "spring weather scenario" emerging, you might just be right. A heat ridge over the Greater Antilles will be flexing its muscles, so to speak, steering storms through Texas after the energy digs into the Desert Southwest. The gradient between the disturbances and the ridge complex will contribute both dry air from the Mexican mainland as well as warm, moist and increasingly unstable values from the Bay of Campeche. Matched against pools of cold air dropping out of the northern Pacific Ocean (with accompanying strong dynamics aloft), the set-up will favor excellent chances for intense convection and locally heavy rain.
A new and strong impulse in the flow will drop into Arizona and New Mexico on Wednesday, setting up the deep tropical moisture fetch into Texas from the equatorial regions (view this effect on the GOES WEST satellite image). As a warm front takes shape ahead of the surface low pressure center, and lurches northward, showers and thunderstorms will increase in coverage and intensity. I am very concerned about the formation of discrete supercells or an MCS (Mesoscale Convective System) in the vicinity of San Antonio and Austin on Wednesday night, as these storms could be in the heavy-to-severe spectrum and continue into later morning on Thursday. The upcoming trend in weather will favor increasing chances for excessive precipitation from Texas through most of the Old South (with, for the time being, snowfall being limited to the Upper Midwest). So drought conditions in our part of the world look to be relaxing.
The extended forecast looks to be (at the very least) quite bothersome. There seems to be emerging agreement among the various computer models that another, much more intense, shortwave will dig into Texas around February 28. Unlike other impulses which weaken moving into the faint ridge axis along the East Coast, this feature may turn into a dangerous synoptic-scale storm. The presence of a Rex signature over Hudson Bay and Quebec looks to force the system along the Interstate 20 corridor before recurvature takes shape near Atlanta GA on March 1. After that point, details are somewhat hazy; the ensemble members seem to be hinting at a trajectory into southeastern Virginia and then into the Massachusetts Island (yes, that is a snow/sleet threat for friends north of Richmond VA). The bottom line is that the first few days of March will be cold after a prominent threat for severe weather in Houston on the last day of February.
Useful Links
NWS Mesonet Observations
Mosaic NEXRAD For U.S.
AHPS Precipitation Analysis Page
The Forecast
Tuesday: Sunny and mild. Highs 68 Goodrich to 72 Alvin
Tuesday Night: Increasing cloudiness with a shower possible very late. Breezy after midnight. Lows 53 Cold Spring to 57 Manvel
Wednesday: Cloudy, windy and mild with showers. A thunderstorm is possible late day. Highs 66 Shepherd to 70 Iowa Colony
Wednesday Night: Windy and mild with showers and thunderstorms. Some thunderstorms may be severe. Lows 60 Cleveland to 64 Fresno
Thursday: Heavy to severe thunderstorms likely in the morning; some clearing in the afternoon. Highs 71 Roman Forest to 75 Pearland
Weekend Outlook
Friday: Showers and a few thunderstorms in the morning; mostly cloudy in the afternoon. High 72, Low 57
Saturday: Variable cloudiness with a few showers along the Gulf Coast. High 71, Low 56
Sunday: Variable cloudiness, windy, mild and humid with a few showers. High 74, Low 59
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