Area Forecast Discussion
Issued by NWS Jackson, MS

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FXUS64 KJAN 010848
AFDJAN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
348 AM CDT WED APR 1 2015

.DISCUSSION...TODAY THROUGH THURSDAY NIGHT...CHANCES FOR SHOWERS AND
STORMS REMAIN IN THE FORECAST TODAY INTO TONIGHT...PARTICULARLY
ACROSS MY NORTH.  THIS WILL BE AS A RESULT OF A SHORTWAVE...
CURRENTLY MOVING EAST ACROSS NORTHERN MEXICO INTO SOUTHERN TEXAS.
THIS TROUGH WILL WEAKEN AS IT APPROACHES AND PUSHES THROUGH THE
LOWER MISSISSIPPI RIVER VALLEY LATER TODAY INTO TONIGHT.  AHEAD OF
THE SHORTWAVE...RIDGING BUILDING EAST THROUGH THE REGION WILL CAUSE
THE BOUNDARY PLAGUING THE NORTHERN HALF OF THE CWA TO LIFT NORTH AND
OUT OF THE FORECAST AREA.  DESPITE THE TROUGH WEAKENING AS IT
APPROACHES AND MOVES THROUGH THE CWA...WITH A WARM MOIST AND
UNSTABLE AIRMASS OVER THE REGION...IT`LL STILL BE ABLE TO SPARK SOME
CONVECTION OVER PORTIONS OF THE REGION TODAY...WITH SOME ACTIVITY
LINGERING INTO THIS EVENING BEFORE FINALLY DISSIPATING.

WHILE STORMS AREN`T EXPECTED TO BE AS VIGOROUS AS THOSE OBSERVED ON
TUESDAY...WITH SOME MID-LEVEL LAPSE RATES STILL RESIDING OVER THE
REGION...I CAN`T RULE OUT THAT AN INTENSE STORM COULD YIELD SOME
HAIL AND GUSTY WINDS. THAT SAID...BASED OFF FORECAST SOUNDINGS...IT
LOOKS TO BE AN UPHILL BATTLE FOR SUCH CONVECTION AS A LOW-LEVEL CAP
LOOKS TO BE PRESENT ACROSS THE FORECAST AREA FOR MUCH OF THE DAY...IN
ADDITION TO THE BEFORE MENTIONED INCREASED RIDGING BUILDING THROUGH
THE REGION. DUE TO THE CURRENT LOW CONFIDENCE IN SUCH STORMS...I`LL
LEAVE THE HWO CLEAR FOR THE TODAY PERIOD.

WARM HUMID CONDITIONS WILL CONTINUE ON THURSDAY.  ONCE AGAIN...THE
RESULT OF DAYTIME HEATING IN THIS AIRMASS...COUPLED WITH A DISTURBANCE
ALOFT TRAVERSING THE FORECAST AREA IN ZONAL FLOW ALOFT...WILL CAUSE
SOME CONVECTION TO DEVELOP ACROSS A LARGER PORTION OF THE FORECAST
AREA...COMPARED TO RECENT DAYS. /19/

FRIDAY THROUGH TUESDAY...AT THE BEGINNING OF THE PERIOD MID LEVEL
ZONAL FLOW WITH SURFACE SOUTHERLY FLOW AND WIDESPREAD 60S DEWPOINTS
WILL HAVE ALREADY BEEN IN PLACE FOR SOME TIME WITH STRONG CAPPING
INVERSION AT H85.

NICE MID LEVEL WAVE WILL BEGIN MOVING OUT OF THE ROCKIES INTO THE
PLAINS AS SURFACE LOW PRESSURE AND ASSOCIATED COLD FRONT TAKE SHAPE
FROM NW AR TO N TX. CONVECTION WILL BE SLOW TO DEVELOP OVER THE AREA
AHEAD OF THE BOUNDARY...BUT INCREASING LOW LEVEL WIND FIELDS AND
MOISTURE ADVECTION SHOULD BE AS SUCH BY AFTERNOON TO WASH AWAY THE
CAP AND ALLOW A LINE OF STORMS TO DEVELOP IN CLOSE PROXIMITY TO THE
FRONTAL BOUNDARY.

GFS/EC HAVE BACKED OFF THE CONVECTIVE INDICES A BIT THIS RUN...ONLY
SHOWING ABOUT 1500-2000 J/KG OF CAPE. THIS PROBABLY OWING TO THE
DEPTH OF LOW LAYER WARM AIR. NEVERTHELESS...H7-H5 LAPSE RATES STILL
LOOK GOOD AT 7-7.5 C/KM AND 25-30 VERTICAL TOTALS. DEEP LAYER SHEAR
STILL LOOKS GOOD WITH 50+ KNOTS OVER NORTH MS AND INCREASING THROUGH
THE DAY. SPEAKING OF NORTH MS...WITH THE AFOREMENTIONED SHEAR AND
TIME OPTIMIZED FOR BEST UTILIZATION OF THE AMBIENT CAPE...THAT AREA
SHOULD HAVE THE GREATEST POTENTIAL FOR SEVERE WEATHER WITH DAMAGING
WINDS AND HAIL BEING THE MAIN THREAT.

FRONT LOOKS TO PUSH RAPIDLY SE AND OUT OF THE AREA OVERNIGHT
ALLOWING MID LEVEL SHORTWAVE RIDGING AND SURFACE HIGH PRESSURE WITH
A COOLER AIRMASS TO MOVE IN SATURDAY. FAST PACED ZONAL FLOW PATTERN
WILL PUSH THE FAIR WETHER MAKER EAST BY SUNDAY ALLOWING SOUTHERLY
FLOW TO DEVELOP AS OLD FRONTAL BOUNDARY PUSHES NORTH AS A WARM FRONT
BY AFTERNOON. SOUTHERLY FLOW UP AND OVER THE BOUNDARY WILL ALLOW
ISENTROPICALLY INDUCED SHOWERS TO BREAK OUT SUNDAY AFTERNOON AND
CONTINUE THROUGH MONDAY UNTIL THE BOUNDARY LIFTS OUT OF THE AREA. /26/

&&

.AVIATION...VFR CONDITIONS WILL PREVAIL AT MOST TAF SITES THROUGH
THE PERIOD.  SOME CONVECTION DEVELOPING MAINLY NORTH OF THE
INTERSTATE 20 CORRIDOR THIS AFTERNOON COULD BRING A BRIEF BOUT OF
MVFR/IFR CEILINGS AND/OR VISIBILITIES AT SITES IF OBSERVED ON
STATION.  CONVECTION WILL BEGIN TO DISSIPATE AFTER SUNSET THIS
EVENING.  WINDS TODAY WILL BE SOUTHERLY BETWEEN 5-10 KNOTS...AND
SUBSIDE TO AROUND 5 KNOTS FROM THE SOUTH OVERNIGHT. /19/

&&

.PRELIMINARY POINT TEMPS/POPS...
JACKSON       80  63  83  65 /  24  14  24  10
MERIDIAN      80  61  82  63 /  28  14  21  14
VICKSBURG     81  64  84  65 /  19  14  27  11
HATTIESBURG   84  64  84  64 /   8  10  16   8
NATCHEZ       81  64  83  65 /  10  12  25  10
GREENVILLE    78  63  81  66 /  35  28  44  14
GREENWOOD     79  62  81  65 /  36  26  41  14

&&

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

$$

19/26


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