000 
FXUS64 KMEG 082049
AFDMEG

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEMPHIS TN
349 PM CDT THU MAY 8 2008

.DISCUSSION...SURFACE ANALYSIS THIS AFTERNOON PLACES A COLD FRONT
ALONG THE MISSISSIPPI RIVER. REGIONAL RADAR TRENDS OVER THE PAST 4
TO 5 HOURS HAVE INDICATED REDEVELOPMENT OF SHOWERS ASSOCIATED WITH
THE WEAK COLD FRONT AND DAYTIME HEATING INTERACTING WITH A WARM
AND MOIST...UNSTABLE ATMOSPHERE. TEMPERATURES THIS AFTERNOON HAVE
RISEN INTO THE 70S DESPITE PARTLY SUNNY TO MOSTLY CLOUDY SKIES.
MAIN FORECAST CONCERNS ARE SEVERE THUNDERSTORM POTENTIAL FRIDAY
AND AGAIN SATURDAY NIGHT.

.SHORT TERM...(TONIGHT THROUGH SUNDAY)...SHOWERS SHOULD COME TO
AN END BY EARLY EVENING WITH CLOUD COVER DIMINISHING WITH THE LOSS
OF DAYTIME HEATING. LOW TEMPERATURES WILL BE MILD WITH READINGS
RANGING FROM THE UPPER 50S NORTH TO LOWER 60S SOUTH.

NAM/GFS INDICATE AN MCS DEVELOPING TONIGHT ACROSS THE CENTRAL
PLAINS AND MOVING INTO THE MIDDLE MISSISSIPPI VALLEY FRIDAY AND
PORTIONS OF THE MID SOUTH FRIDAY AFTERNOON INTO FRIDAY EVENING.
MODEL SOUNDINGS INDICATE ATMOSPHERE MAY REMAIN CAPPED MOSTLY SOUTH
OF I-40 ON FRIDAY WITH AREAS TO THE NORTH OF I-40 SEEING THE BEST
CHANCE OF CONVECTION AS AN UNSTABLE AIRMASS COMBINES WITH REMNANTS
OF UPSTREAM CONVECTION. SURFACE BASED CAPES BETWEEN 1500 TO 2300
J/KG...LI/S AROUND -6...VERY STEEP 700-500 MB LAYER MID LEVEL LAPSE
RATES ABOVE 7 C/KM...AND A SOMEWHAT FAVORABLE WIND FIELD ALOFT
INDICATE A FEW THUNDERSTORMS MAY BECOME SEVERE WITH LARGE HAIL AND
DAMAGING WINDS AS THE SEVERE WEATHER THREATS. 

THE NEXT AREA OF CONCERN FOR SEVERE THUNDERSTORM POTENTIAL IS
SATURDAY NIGHT AS ANOTHER UPPER LEVEL TROUGH AND AREA OF LOW
PRESSURE MOVE THROUGH THE MISSISSIPPI VALLEY. STEEP MID LEVEL
LAPSE RATES...STRONG INSTABILITY...AND FAVORABLE WINDS ALOFT
INDICATE LARGE HAIL...DAMAGING WINDS...AND POSSIBLY TORNADOES ARE
POSSIBLE.

.LONG RANGE...(MONDAY THROUGH THURSDAY)...NOT MUCH CHANGE IN THE
OVERALL UPPER AIR PATTERN EXPECTED ACROSS NORTH AMERICA AS LONG
RANGE MODELS (ECMWF/GFS) INDICATE EASTERN UNITED STATES WILL
REMAIN PRIMARILY IN ZONAL TO NORTHWEST FLOW ALOFT THROUGH THE
PERIOD. UPPER LEVEL RIDGING WILL BRING RAIN FREE WEATHER TO THE
MID SOUTH MONDAY WITH CHANCES FOR SHOWERS AND THUNDERSTORMS
RETURNING BY TUESDAY AFTERNOON AS ANOTHER UPPER LEVEL TROUGH AND
ASSOCIATED SURFACE COLD FRONT MOVE THROUGH THE REGION ON WEDNESDAY. 

&&

.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&

$$


CJC