Post by Randy - Brandon, MS on Feb 4, 2009 5:57:23 GMT -6
ZCZC SPCSWOD48 ALL
ACUS48 KWNS 040913
SPC AC 040913
DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0313 AM CST WED FEB 04 2009
VALID 071200Z - 121200Z
...ACTIVE SEVERE WEATHER PATTERN FORECAST OVER AREAS OF THE
SOUTHERN/CENTRAL U.S. NEXT WEEK...
...DAY5/SUNDAY TO MONDAY MORNING...
MREF AND RECENT GFS RUNS CONTINUE TO EXHIBIT GOOD RUN-TO-RUN
CONSISTENCY IN THE DEVELOPMENT OF A VIGOROUS SHORT WAVE TROUGH
EJECTING NEWD FROM AZ TO THE SRN/CNTRL PLAINS SUNDAY INTO MONDAY.
ECMWF CONTINUES TO BE TYPICALLY SLOWER THAN THE GFS WITH THE TROUGH
POSITION THROUGH 120 HOURS/SUNDAY EVENING. BUT...RECENT ECMWF RUNS
HAVE BEEN TRENDING TOWARD A MORE PROGRESSIVE/EWD H5 TROUGH POSITION
NOW IN CLOSE AGREEMENT WITH THE MREF H5 MEAN. THIS LENDS CONFIDENCE
IN THE SYNOPTIC PATTERN BEING FORECAST ACROSS THE SRN PLAINS BY
SUNDAY EVENING.
GIVEN PRONOUNCED LARGE SCALE JET COUPLING AND STRENGTHENING ASCENT
DEVELOPING ACROSS TX/OK/KS THROUGH SUNDAY...DYNAMIC AND KINEMATIC
ENVIRONMENT SHOULD INCREASINGLY SUPPORT THE DEVELOPMENT OF SEVERE
STORMS WITH HAIL AND HIGH WINDS. AIR MASS QUALITY WILL OBVIOUSLY
PLAY A ROLE IN OVERALL SEVERE STORM COVERAGE AND MODE. NUMEROUS
RECENT INTRUSIONS OF COLD/DRY AIR INTO THE NW GULF SUGGEST THAT
MOISTURE RETURN AND RESULTANT CAPE WITH THIS UPCOMING SYSTEM WILL
LIKELY BE LIMITED. HOWEVER...THIS LIMITING FACTOR SHOULD BE SOMEWHAT
OFFSET BY THE MAGNITUDE OF FORCING AND SHEAR FORECAST TO ACCOMPANY
THE UPPER TROUGH...SURFACE LOW...AND FRONT MOVING OVER THE REGION
THROUGH SUNDAY NIGHT/MONDAY MORNING.
...DAY6/MONDAY TO TUESDAY MORNING...
PRIMARY MID/UPPER LEVEL DISTURBANCE/VORT MAX AND SURFACE LOW ARE
FORECAST TO LIFT NWD/NEWD TO THE UPPER MS VALLEY THROUGH EARLY
TUESDAY. IT APPEARS POSSIBLE THAT SEVERE STORMS...POSSIBLY TAKING
THE FORM OF A SQUALL LINE...MAY SPILL OVER FROM SUNDAY INTO MONDAY
FROM THE OZARKS TO ARKLATEX. OR...STORMS MAY REDEVELOP ALONG THIS
AXIS DURING THE DAY. THIS ACTIVITY MAY STRENGTHEN DURING THE DAY
WITHIN CONFLUENT WARM CONVEYOR BELT WHERE DEEP-LAYER SHEAR SHOULD BE
MORE THAN ADEQUATE FOR ORGANIZED/PERSISTENT UPDRAFTS/SUPERCELLS.
...DAY7-8/THROUGH MIDWEEK...
LARGE SCALE PATTERN IS FORECAST TO REMAIN QUITE ACTIVE/DYNAMIC WITH
GFS AND ECMWF BOTH FORECASTING ANOTHER DEEP TROUGH DEVELOPING OVER
THE PLAINS ON WEDNESDAY/DAY8. HOWEVER...IN THE WAKE OF POTENTIALLY
WIDESPREAD CONVECTION ACROSS THIS REGION ON PRIOR DAYS...SEVERE
STORM PREDICTABILITY AT THIS FORECAST RANGE IS LOW.