Severe Thunderstorm Warning 137, NWS Jackson, MS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
315 AM CST MON MAR 12 2001

VERY ACTIVE MORNING OVER MY CWFA WITH ELEVATED CONVECTION ALREADY DEVELOPING
ALONG AND TO THE NORTH OF THE SURFACE-BASED WARM FRONT NOW OVER
EXTREME SOUTHERN ZONES. DEW PTS INCREASING INTO THE 60S ALONG AND
BEHIND THE WARM FRONT. SVR TSTORM WATCH 54 IN EFFECT THROUGH 12Z
GENERALLY SOUTH OF I-20 CORRIDOR FOR HAIL/HIGH WINDS AS THIS IS
WHERE STRONGEST ISENTROPIC LIFT/LLJ AND ASSOCIATED 850MB WAA IS
SITUATED...ALONG WITH DRIER AIR IN MID LVLS IS PUNCHING IN ACROSS
THE MS RIVER PER WATER VAPOR IMAGERY. WITH CONVECTION FIRING
RAPIDLY...WILL BE FAIRLY BRIEF HERE. MODELS HAVE SOME MINOR
DISCREPANCIES ON TIMING OF FAST WAVES IN SWLY FLOW ALOFT AHEAD OF
UPPER TROUGH EXITING ONTO THE PLAINS. BUT THESE ARE MINOR AND A
BLEND OF META/AVN LOOKS THE WAY TO GO HERE.

LOOKING FOR A SQUALL LINE/LEWP TO MOVE INTO SE ZONES EARLY THIS MORNING
AND WEAKEN AS MIXING OCCURS AFTER 12Z...BUT...OUTFLOW BOUNDARY AND
POSSIBLY A PRE-FRONTAL TROUGH SHOULD EXIST OVER CENTRAL/SOUTHERN
ZONES AFTERWARDS BEHIND WARM FRONT THAT SURGES NORTH THROUGH MY CWFA
TODAY. DEEPENING SURFACE LOW OVER EASTERN KS TO MOVE INTO SE IA BY
MIDDAY. BEST LIFT/DIVERGENCE ALOFT AND LOW LVL MOISTURE/INSTABILITY
EXPECTED OVER MY SOUTHERN ZONES TODAY AS LEFT EXIT REGION OF
100-120KT SUB-TROPICAL JET SETS UP ACROSS THE LA/MS/AL GULF COAST.
FEEL BEST CHANCE FOR SEVERE (DAMAGING WINDS AND HAIL) WILL BE OVER
THE SOUTHERN HALF OF CWFA WHERE BEST CAPES (1500-2000 J/KG) WILL
RESIDE THIS AFTERNOON...YET SEVERE STORM OR TWO OVER NORTH ZONES
WILL NOT BE OUT OF THE QUESTION AS HIGH SHEAR AND CAPES NEARING 1000
J/KG WILL CONTINUE THROUGH AT LEAST MIDDAY OR SO (SEE SWODY1 FOR
MORE DETAILS)...THEN 850 FLOW VEERS WEST HERE BY LATE AFTERNOON.
COLD FRONT ENTERS NW ZONES LATE AFTERNOON...THEN EXITS SE ZONES
SOMETIME AFTER 06Z TUESDAY. ONGOING FORECAST TODAY/THIS EVENING
LOOKS PRETTY GOOD AND EXPECT TO ONLY MAKE MINOR MODIFICATIONS FOR
SEVERE POTENTIAL/ETC.

OTHERWISE....SURFACE HIGH PRESSURE MOVES IN LATE TONIGHT IN WAKE OF
UPPER TROUGH LIFTING INTO THE GT LAKES.  WNW FLOW TUESDAY AND
TUESDAY NIGHT TO RESULT IN MOSTLY CLEAR AND NEAR SEASONAL CONDITIONS
AS BEST 850 CAA SHIFTS EAST RATHER THAN SOUTH. FWC/MAV TEMPS CLOSE
THROUGHOUT THE 48-60 HR PERIOD AND WILL STAY CLOSE.

24 HR QPF DISCUSSION...EXPECTED LOCAL 1-2 INCH AMOUNTS SOUTH/CENTRAL
ZONES BY DAY/S END WITH A DECREASE TO 0.25/0.50 AREA AVERAGES UP IN
THE NORTH. RAIN SHOULD END OVER THE SE CWFA BY 06-12Z TUESDAY.

.EXTENDED...WEDNESDAY WILL BE SIMILAR TO TUESDAY (SEASONABLE AND
DRY)...YET SHOULD SEE FLOW RETURN FROM THE SOUTH IN A HURRY AS NEXT
SHORTWAVE TROUGH DEEPENS OVER TX AND MOVE ACROSS WED NIGHT INTO
THURSDAY PER AVN...WITH NOGAPS SHOWING SIMILAR RESULTS. THE HEAVIEST
QPF LOOKS TO EXIST OVER THE SOUTHERN HALF ONCE AGAIN. WILL MENTION
RAIN CHANCES ENDING ON FRIDAY AS BOTH NOGAPS/AVN LIFT THE TROUGH OUT.
IN BEHIND...IT WILL COOL DOWN AND DRY OUT INTO THE WEEKEND. WILL
JUST MAKE A FEW MINOR TWEAKS TO CURRENT EXTENDED FOR FRIDAY.

PRELIM NUMBERS...
JAN 74/50/70|/42 +400
MEI 73/52/71/40 +500

.JAN...
MS...NONE.
LA...NONE.
AR...NONE.
05/

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JACKSON MS
920 AM CST MON MAR 12 2001

TIME(CST)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....PARISH/COUNTY LOCATION....

0715 AM    WISNER                    LA   WIND DAMAGE
03/12/01   FRANKLIN                       TREES AND POWER LINES
                                          DOWN. REPORTED BY SO

0850 AM    FOXWORTH                  MS   1 INCH HAIL
03/12/01   MARION                         QUARTER HAIL REPORTED BY
                                          MARION EOC

0905 AM    15 S BROOKHAVEN           MS   WIND DAMAGE
03/12/01   LINCOLN                        MOBILE HOME ROOF BLOWN
                                          OFF. TREES AND POWER LINES
                                          DOWN.  REPORTED BY LINCOLN
                                          CO CD DIRECTOR.

0905 AM    5 NE HATTIESBURG          MS   WIND DAMAGE
03/12/01   FORREST                        ROOF BLOWN OFF OF HOUSE.
                                          NUMEROUS TREES DOWN.
                                          REPORTED BY FORREST CO
                                          EOC.