Even though the threat of severe thunderstorms might attract some attention, for much of Central Texas the threat of fire weather tomorrow is going to be much more considerable and cannot be understated. The
SPC notes that
Dangerous, potentially historic, fire-weather conditions are likely over portions of the Edwards Plateau and south Texas Plain Tuesday.
Extremely critical fire weather is forecast for these areas, including the Austin and San Antonio areas.
This is the first time since 2006 that the SPC has placed many of these areas under the risk of extremely critical fire weather.
Driving this fire weather threat is the abnormally strong trough that will be moving across the Central US tomorrow. This will result in a
powerful mid-level jet core moving across Central Texas. As the latest AFD from NWS Austin/San Antonio notes,
"there is strong consensus among model guidance that winds aloft will be within the upper echelon of climatological values". Based on model reanalyses, some of the winds aloft will be at record strength tomorrow afternoon. While the front tomorrow morning will bring in some cooler air at first, that will make it much easier for the surface boundary layer to grow upwards rapidly. This will make it easier to mix down the strong winds found aloft. Some of the guidance shows
turbulent mixing occurring from the surface all the way to 7-9 thousand feet. That means momentum from the air that high up can potentially make it to the surface. For these reason, there's the potential for
widespread 45-55 mph wind gusts occurring Tuesday throughout much of the state with sustained winds possibly topping 30 mph. This won't be short-lived either, with these conditions lasting for at least several hours.
Very dry air will coincide with the winds, to the tune of 5 to 15% relative humidity values over South-Central, South, and West Texas. There's been a lot of prescribed burns as of late, so hopefully folks are getting the memo. Any fire that ignites is going to spread rapidly and erratically under these conditions. This combination of widespread wind and widespread dryness to this extent and magnitude is not common for Central Texas.
