Mesoscale Discussion 822 Also Involving Tornado Watch 277

MESOSCALE DISCUSSION 0822
NWS STORM PREDICTION CENTER NORMAN OK
1237 PM CDT THU MAY 08 2008
AREAS AFFECTED...NRN AL...NW GA INTO ERN TN
CONCERNING...TORNADO WATCH
277
...
VALID 081737Z - 081900Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 277 CONTINUES.
PRE-SQUALL LINE BOUNDARY LAYER NORTH OF BIRMINGHAM...AND
PARTICULARLY NORTH OF THE TENNESSEE RIVER INTO MIDDLE/EASTERN
TENNESSEE...WITH THE EXCEPTION OF THE WESTERN SLOPES OF THE
APPALACHIANS...REMAINS RAIN-COOLED/STABILIZED. AND...CLOUD COVER
FROM APPROACHING CONVECTION WILL PROBABLY PRECLUDE SIGNIFICANT
FURTHER DESTABILIZATION. BUT...AT LEAST AN ELEVATED MOISTENING AND
FORCING ON THE SOUTHERN FRINGE OF THE SHORT WAVE IMPULSE LIFTING
THROUGH KENTUCKY/TENNESSEE WILL LIKELY MAINTAIN VIGOROUS SQUALL LINE
INTO AREAS NEAR/NORTHEAST OF LOOKOUT MOUNTAIN BY AROUND 20Z.
LOW-LEVEL SHEAR NEAR THE NOSE OF A 40-50 KT LOW-LEVEL JET WILL
REMAIN SUFFICIENT FOR A RISK FOR TORNADOES IN SUPERCELLS WITHIN THE
SQUALL LINE...BUT DAMAGING STRAIGHT LINE WINDS MAY BE THE PRIMARY
SEVERE THREAT...WITH SOME HAIL ALSO POSSIBLE.
KERR.. 05/08/2008