6AM Day 1 Convective Outlook for Friday, January 23. NO SEVERE THUNDERSTORM AREAS FORECAST
SUMMARY
Scattered weak thunderstorm activity is likely today into tonight across the Texas Big Bend region into central Texas.
Synopsis
Early-morning satellite imagery shows a well-defined upper low off the northern Baja California coast, with a subtle lead shortwave moving into northwest Mexico and modest shortwave ridging from central Mexico into southeast AZ/southwest NM. Largely zonal flow persists across much of the central and eastern CONUS.
Surface analysis reveals an expansive 1048 mb high extending from the southern Canadian Prairies through the central Plains, mid MS Valley, and much of the OH Valley. Very cold temperatures accompany this high, and an intense cold front is currently pushing southward across the TX Panhandle, northern OK, and northern AR. This same front is pushing southeastward across the middle OH Valley.
Big Bend Region into North/Central Texas
Some modest low-level moisture advection is ongoing ahead of the cold front from the TX Coastal Plain into the TX Hill Country. This advection is forecast to continue throughout the day, likely bringing upper 50s/low 60s dewpoints as far northwest as the Edwards Plateau before interacting with the front this afternoon. Heating will be tempered by abundant cloud cover and mid-level lapse rates will be poor. Even so, the anticipated low-level moisture coupled with cold mid-level temperatures should result in a relatively confined area of moderate buoyancy (i.e. MLCAPE 500-1000 J/kg) tonight. Additionally, deep-layer vertical shear will be strong, resulting in environmental conditions that could support a strong/marginally severe storm or two. However, the overall threat will be mitigated by the undercutting nature of the cold front and likely storm interactions. The limited duration and isolated nature of the severe threat currently precludes the need for probabilities.
Farther north and west, a large area of precipitation is expected to develop behind the front, supported by the strengthening southwesterly flow aloft and associated broad isentropic ascent. Cooling mid-level temperatures may result in minimal buoyancy (mostly after 03Z), with a few deeper convective elements within the precipitation shield capable of producing lightning amid freezing rain and/or sleet.