HAMweather.com Area Forecast Discussion for County Warning Area JAN

Thu, 16 Feb 2012 03:19:00 GMT
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON MS
919 PM CST WED FEB 15 2012

.UPDATE...A WEAK MESOLOW HEADING EWD ACROSS SRN MS ALONG A NATCHEZ TO
QUITMAN LINE. A SHORT LINE OF STRONG/SVR STORMS DEVELOPED JUST S OF
THE LOW PRODUCING SOME TREE DAMAGE ALONG THE HIGHWAY 84 CORRIDOR
ALONG WITH SOME QUICK BURSTS OF 1 TO 1.5 INCHES OF RAINFALL. THE BACK
EDGE OF THE HEAVIER RAINS NOW E OF THE MS RIVER AND MOVING NICELY
TOWARD THE E AT 40KTS OR SO. RISK FOR SEVERE SHOULD GRADUALLY
DIMINISH THROUGH SERN MS AS TSRA MOVES INTO DRIER AIR. MEANWHILE...
THE ACTUAL COLD FRONT LAGS BEHIND FROM THE OZARKS INTO N CENTRAL TX
AND WILL PROBABLY NOT REACH OUR MS DELTA REGION UNTIL AFTER DAYBREAK
BEFORE SWEEPING SEWD THROUGH THE CWFA BEFORE MIDDAY THURSDAY.

EXPECT THE RISK FOR TSRA TO END WITH THE CURRENT MCS OVER CENTRAL AND
ERN MS. THERE IS SOME CONCERN FOR A SHALLOW WAKE LOW SETTING UP
BETWEEN WINNSBORO AND VICKSBURG WHERE PRESSURES FALLING OFF A BIT.  
IF THIS OCCURS WE COULD SEE GUSTY SELY WINDS OF MAYBE 30-40MPH WITH
THE END OF THE RAINS ACROSS THE METRO AREA AND POINTS SWD ALONG I-55
DURING THE NEXT 3-6HRS. WILL CONTINUE TO MONITOR THIS POTENTIAL./40/

.AVIATION...MVFR CONDITIONS DOMINATING CWFA WITH LOCALIZED IFR IN
RAIN AND TSRA. SOME VSBY RESTRICTIONS BELOW 1 MILE WILL BE LIKELY IN
THE HEAVIER DOWNPOURS. AREAS OF MVFR OR WORSE FOG LIKELY TO DEVELOP
IN THE WAKE OF THE TSRA COMPLEX CROSSING THE REGION...ESPECIALLY IN
NERN LA/SERN AR AND NWRN THIRD OF MS THROUGH 14Z. THEN A COLD FRONT
WILL BEGIN PUSHING ACROSS THE REGION AS A BAND OF RAIN DEPARTS WITH 
IT DURING THE MORNING WITH WINDS SHIFTING TO THE NW IN ITS WAKE.
VFR CONDITIONS START RETURNING FROM NW TO SE 16-21Z./40/

.PREV DISCUSSION... /ISSUED 300 PM CST WED FEB 15 2012/ 

...HEAVY RAIN AND SOME SEVERE STORMS POSSIBLE TONIGHT...
DISCUSSION...SHORT TERM(TONIGHT THROUGH FRIDAY NIGHT) THE PRIMARY
CONCERNS WILL BE FOR A STORM SYSTEM THAT WILL COME OUT OF THE
SOUTHERN PLAINS THAT WILL AFFECT THE REGION FOR LATE THIS AFTERNOON
INTO THE OVERNIGHT HOURS. THE ISSUES WILL BE FOR SOME SEVERE
POTENTIAL IN THE SOUTHWEST QUARTER FOR THIS EVENING AS WELL AS
LOCALLY HEAVY RAINS. THERE WILL ALSO BE SOME STRONG STORM ISSUES IN
THE SOUTHEAST QUARTER OVERNIGHT. SECONDARY ISSUES WILL BE THE RETURN
OF RAIN FOR FRIDAY INTO FRIDAY NIGHT...FOLLOWED BY POPS AND TEMPS.

LATEST SATELLITE IMAGERY SHOWED AN APPROACHING SHORT WAVE WITH AN 
ASSOCIATED CLOSED LOW OVER THE SOUTHERN PLAINS. AN ASSOCIATED MCS
WITH SOME LINE SEGMENTS WAS CROSSING WESTERN LOUISIANA. ON THE
SURFACE AN AREA OF LOW PRESSURE WAS OBSERVED OVER OKLAHOMA WITH AN
ASSOCIATED WARM FRONT PUSHING NORTHEAST FROM OKLAHOMA THROUGH
LOUISIANA TO APPROACHING SOUTHWEST MISSISSIPPI. SO EXPECT THE MCS TO
START TO AFFECT NORTHEAST LOUISIANA AND SOUTHEAST ARKANSAS LATE THIS
AFTERNOON AND SPREAD EAST ACROSS THE REGION OVERNIGHT AS THE WARM
FRONT PUSHES NORTHEAST ACROSS THE REGION. THERE WILL BE ENOUGH
SHEAR...HELICITY AND SOME INSTABILITY FOR A FEW SEVERE STORMS IN THE
SOUTHWEST QUARTER OF THE REGION OVERNIGHT..GENERALLY ALONG AND SOUTH
OF I-20 AS WELL AS ALONG AND WEST OF I-55. AS THE MCS PUSHES EAST A
FEW STRONG STORMS WILL AFFECT THE SOUTHEAST QUARTER OF THE REGION.
THE BEST FORCING WITH THIS SYSTEM WILL LIFT NORTH OF THE REGION
DURING THE NIGHT. OVER THE SOUTHWEST AREAS LINE SEGMENTS...SUPERCELLS
AS WELL AS CLUSTERS OF SEVERE STORMS WILL BE POSSIBLE. THE MAIN RISK
WILL BE HAIL...DAMAGING WINDS AND A FEW TORNADOES IN THE SOUTHWEST.
OUR CHANCES OF THUNDERSTORMS WILL DECREASE FROM THE NORTHWEST AFTER
MIDNIGHT. THE ASSOCIATED COLD FRONT WILL BE SLOW TO MOVE THROUGH THE
REGION FROM THE WEST. EXPECT ELEVATED CONVECTION TO PUSH INTO THE
WEST FOR THIS AFTERNOON...THEN SPREAD ACROSS THE REST OF THE REGION
BY THIS EVENING. EXPECT IT TO BECOME MORE SURFACE BASE IN THE WEST
AND SOUTHWEST LATE THIS AFTERNOON BEFORE SPREADING ACROSS MAINLY THE
SOUTH HALF FOR TONIGHT. HOWEVER IF WE DO NOT REACH THE EXPECTED
INSTABILITY IT IS POSSIBLE THAT IT COULD BE MORE OF A HEAVY RAIN
EVENT. IN THE CASE OF HEAVY RAIN OPTED NOT TO GO WITH A FLASH FLOOD
WATCH WITH THE MOVEMENT OF THIS SYSTEM. COULD SEE 1 TO 3 INCH AMOUNTS
POSSIBLE. MODELS TRY TO KEEP INSTABILITY ACROSS THE REGION WITH THE
SLOW FRONTAL PASSAGE ON THURSDAY. SO KEPT LOWER CONVECTIVE POPS FOR
THURSDAY. A SOUTHERN STREAM SYSTEM COMBINED WITH A GULF LOW WILL COME
TO THE REGION FROM THE WEST...WHICH WILL HELP TO SPREAD RAIN ACROSS
THE REGION FOR FRIDAY INTO FRIDAY NIGHT. IT WILL START OUT AS LIGHT
RAIN DURING THE DAY...THEN AS ISENTROPIC LIFT INCREASES IT WILL
BECOME MODERATE RAIN ON FRIDAY NIGHT. AS FAR AS TEMPS ARE CONCERN
WENT WITH A BLEND OF GMOS AND MAV NUMBERS. AS FAR AS POPS ARE CONCERN
WENT WITH CURRENT POPS FOR TONIGHT AS WELL AS A BLEND OF MAV AND NAM
GUIDANCE./17/

LONGER TERM DISCUSSION...SATURDAY THROUGH NEXT WEDNESDAY SLIGHTLY
COOLER DRIER CONDITIONS WILL EXIST OVER THE FORECAST AREA HEADING
INTO THE WEEKEND. BEGINNING FRIDAY NIGHT THOUGH...RAIN CHANCES WILL
BE ON THE INCREASE OVER THE ARKLAMISS REGION AS A SURFACE LOW
DEVELOPS OVER THE NORTHWEST GULF OF MEXICO IN RESPONSE TO A SHORTWAVE
SWINGING EAST ACROSS THE SOUTHERN PLAINS. THIS SURFACE LOW WILL SHIFT
EAST NORTHEAST ACROSS THE NORTH CENTRAL GULF OF MEXICO DURING THE
COURSE OF THE DAY SATURDAY CAUSING RAIN TO SPREAD ACROSS THE MAJORITY
OF THE FORECAST AREA...ESPECIALLY THE SOUTHERN PORTION OF IT. AS THE
LOW LIFTS NORTHEAST ACROSS THE FLORIDA PANHANDLE AND INTO SOUTHERN
GEORGIA SATURDAY NIGHT...RAIN CHANCES WILL GRADUALLY COME TO AN END
FROM WEST TO EAST. CLOUDS LOOK TO HANG AROUND INTO SUNDAY MORNING
THOUGH AS THE UPPER TROUGH CONTINUES TO SWING ACROSS THE REGION.

ONCE AGAIN...WITH NORTHERLY FLOW OVER THE CWA...COOLER CONDITIONS 
WILL EXIST ON SUNDAY AS SKIES CLEAR.  AFTER A COUPLE OF RAIN-FREE 
DAYS SUNDAY AND MONDAY...RAIN CHANCES JUMP BACK INTO THE FORECAST 
MONDAY NIGHT AND CONTINUE THROUGH WEDNESDAY AS YET ANOTHER SERIES OF 
SYSTEMS ARE POISED TO DEVELOP TO OUR WEST...AND BEGIN TO SLOWLY  
SHIFT EAST TOWARDS US. /19/17/

.PRELIMINARY POINT TEMPS/POPS...
JACKSON       58  71  46  63 / 100  19   8  17 
MERIDIAN      58  74  46  66 / 100  45   7  15 
VICKSBURG     54  70  46  62 / 100  11   9  19 
HATTIESBURG   59  76  51  65 / 100  39   9  36 
NATCHEZ       54  70  50  63 / 100  12  14  27 
GREENVILLE    52  65  43  61 /  90  11   8   9 
GREENWOOD     52  69  43  63 /  91  11   6   9 

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.