Southern Us Severe Weather Outbreak Weds

[SNOW_JOKE]

NOAA Forecast for the 18th, area between Lafayette and Panama City as far north as Memphis. Could give a Severe Storm outbreak if convection is initiated with a 30% probability,

DAY 4-8 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

0357 AM CST SUN FEB 15 2009

VALID 181200Z - 231200Z

...DISCUSSION...

DAY 4...

STRONG SRN BRANCH UPPER JET WILL ADVANCE INTO THE LOWER MS...TN AND

OH VALLEYS WED WHERE IT WILL MERGE WITH NRN STREAM IMPULSES WITH

SUBSEQUENT CONSOLIDATION AND AMPLIFICATION OF A TROUGH OVER THE ERN

STATES WED NIGHT. SURFACE LOW TRACK WILL REMAIN TIED TO STRONGER

FORCING WITHIN UPPER JET EXIT REGION. THIS FEATURE WILL LIFT NE INTO

THE OH VALLEY OR GREAT LAKES REGION DURING THE DAY. TRAILING COLD

FRONT WILL SWEEP EWD THROUGH THE OH VALLEY AND SERN STATES. THOUGH

OVERALL PATTERN REMAINS SIMILAR AMONG THE MODELS...SOME DIFFERENCES

EXIST IN TIMING AND MESOSCALE DETAILS.

SEVERE WEATHER PROSPECTS REMAIN CONTINGENT PRIMARILY ON DEGREE OF

INSTABILITY THAT CAN DEVELOP IN WARM SECTOR. GULF FRONTAL INTRUSION

MONDAY WILL DELAY BOUNDARY LAYER MODIFICATION OVER THE WRN GULF. BY

WEDNESDAY AN AXIS OF PARTIALLY MODIFIED GULF AIR WILL ADVECT NWD

THROUGH THE LOWER MS VALLEY AND A PORTION OF THE SERN STATES ALONG A

STRONG SWLY LOW LEVEL JET. SEVERAL CLUSTERS OF STORMS MAY DEVELOP

ALONG AND EAST OF ADVANCING FRONT WITHIN THE LOW LEVEL CONFLUENT

FLOW REGIME FROM THE LOWER MS VALLEY INTO PARTS OF THE SERN STATES.

THIS ACTIVITY WILL BE EMBEDDED WITHIN STRONG KINEMATIC PROFILES AND

ANY SURFACE BASED STORMS COULD POSE A THREAT FOR SEVERE WEATHER.

WARM SECTOR INSTABILITY WILL LIKELY REMAIN MARGINAL DUE IN PART TO

WIDESPREAD CLOUDS. THE MARGINAL THERMODYNAMIC ENVIRONMENT AND

LIKELIHOOD THAT THE STRONGER FORCING WILL REMAIN NORTH OF MOIST AXIS

COULD SERVE AS POTENTIAL LIMITING FACTORS.

FARTHER NORTH INTO SRN PARTS OF THE OH VALLEY...COLDER AIR ALOFT AND

STRONGER FORCING WILL EXIST IN VICINITY OF UPPER JET EXIT REGION

WHICH COULD COMPENSATE FOR MORE LIMITED LOW LEVEL MOISTURE. IF

SURFACE HEATING COULD DEVELOP IN DRY SLOT...SOME POTENTIAL FOR

SURFACE BASED STORMS WOULD EXIST WITH A CORRESPONDING INCREASE IN

THE SEVERE TREAT. THIS AREA WILL CONTINUE TO BE MONITORED.

DAY 5-8...SEVERE POTENTIAL APPEARS LOW AT THIS TIME.