Tornado Watch Coming for Portions of Alabama
The SPC is preparing a tornado watch that will be issued within the hour. Severe weather threat is increasing and a tornado watch is needed. A few strong, long-track tornadoes are possible this afternoon and evening. We will also be watching for very large hail and damaging winds.
AREAS AFFECTED...PORTIONS NERN LA...WRN/NRN MS...NWRN AL...SRN MIDDLE TN. CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY VALID 281705Z - 281900Z PROBABILITY OF WATCH ISSUANCE...95 PERCENT SUMMARY...TORNADO WATCH IS HIGHLY PROBABLE WITHIN NEXT HOUR ACROSS DISCUSSION AREA. SUPERCELLS ARE EXPECTED TO DEVELOP IN BKN/SW-NE BAND AND INTENSIFY THROUGH AFTN WITH A FEW SIGNIFICANT/LONG-TRACK TORNADOES POSSIBLE. DISCUSSION...EARLIER CONVECTION HAS LEFT OUTFLOW/DIFFERENTIAL-HEATING BOUNDARY ALIGNED SW-NE ACROSS DISCUSSION AREA...BECOMING MORE DIFFUSE WITH SWWD EXTENT AT SFC. MEANWHILE VIS IMAGERY SHOWS EXPANDING POCKETS OF RELATIVELY CLOUD-FREE AREAS THAT WILL FOSTER SUSTAINED PERIOD OF INSOLATION AND QUICK SBCINH REMOVAL. MODIFIED RAOBS AND FCST SOUNDINGS OVER THIS CORRIDOR SUGGEST 1500-2500 J/KG MLCAPE WILL BUILD NEWD. IN THIS ENVIRONMENT...TSTMS ALREADY ARE DEVELOPING OVER NERN LA INVOF MLU...AND IF NOT ALREADY SFC-BASED...MAY BECOME SO SHORTLY. ADDITIONAL CONVECTION IS LIKELY TO FORM NEWD ACROSS MS INTO SRN MID TN AND NWRN AL AS AIR MASS THERE DESTABILIZES IN NEXT 2-3 HOURS. DEEP-LAYER AND LOW-LEVEL SHEAR EACH ARE FAVORABLE AND WILL REMAIN SO...WITH 50-70 KT EFFECTIVE SHEAR MAGNITUDES. EFFECTIVE SRH SHOULD INCREASE THROUGH AFTN TO AROUND 300 J/KG...AND VWP ALREADY SHOW 300-500 J/KG OF 0-3 KM SRH OVER NERN MS.
Category: Alabama's Weather, Severe Weather