Severe Weather Possible (Feb 20)

[NWIASpotter]

From the latest outlooks, there is a slight risk area still covering portions of the mississippi valley and the ohio valley. More specifically areas of southern IL/southern IN, western KY/western TN, extreme northwest LA, all of AR, as well as the south/southeastern portions of MO.

The reason for this slight risk is for a cold front that will slowly be makings its way across the plains. This front combined with a shortwave trough and the low pressure that will be over the OH/IN areas by tonight should all combine to produce considerable lift for storms. A large plume of warm air and moisture will be in place, which will allow CAPE values to reach around the 1500-2000 J/kg. Lapse rates will be on the increase, as well as considerable shear will be in place.

With these storms, large hail will undoubtably be the highest threat, but with CAPE being quite high an isolated supercell cannot be ruled out. And if the CAPE can raise any higher then more supercells will be likely. With any supercell that develops, high wind and an isolated tornado cannot be ruled out. The area that will be in the greatest risk of seeing some supercells will be the MO/AR/IL/KY/TN areas late this afternoon/evening.

[jkt21787]

Yes, we are watching out for some possible severe weather tonight in the Memphis area. Right now, I would say the best potential will be in NW AR and into MO, where they have been getting some strong surface heating in the last few hours. The satellite is already showing some TCU development there. Here it has been cloudy and raining all day, so there is not much instability. Some clearing is taking place back towards Little Rock, but it probably won't reach us until sunset is already approaching.

However, with low freezing levels present and some elevated instability in place, along with approaching shortwave now getting ready to hit the ozarks, the severe threat still remains. Since the sun will prevent much surface instability, the storms probably wont get supercelluar around here and carry a damaging wind or tornado threat. If the needed surface instability could develop, the shear would certainly support this type of activity though. Right now this appears to be a hail threat, and could be widespread if enough convection develops.

A watch may be issued soon in MO and NW AR, so things are beginning to get fired up.

[NWIASpotter]

Another mesoscale has been issued, but it looks like there won't be a watch issued tonight. Once again the Feb weather doesn't allow a severe weather outbreak.

[WXBUFFJIM]

Gotta watch southern cal also. A possible tornado near Hunington Beach at this time and a severe tstm watch in effect for the LA, San Diego area until 3 pm PST.

Jim

[WXBUFFJIM]

The national weather service has issued a

SEVERE THUNDERSTORM WARNING FOR...
NORTHERN DEKALB COUNTY IN NORTH CENTRAL GEORGIA
NORTHERN FULTON COUNTY IN NORTH CENTRAL GEORGIA

* UNTIL 145 PM EST

* AT 110 PM EST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING NICKEL SIZE HAIL. THIS
STORM WAS LOCATED 8 MILES SOUTHWEST OF SANDY SPRINGS...AND MOVING
EAST AT 50 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
TUCKER...DUNWOODY...DORAVILLE AND CHAMBLEE.