Area Forecast Discussion
Issued by NWS Jackson, MS

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000
FXUS64 KJAN 142126
AFDJAN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
326 PM CST SUN FEB 14 2016

.DISCUSSION...THE MAIN FORECAST FOCUS CONTINUES TO BE A COLD FRONT
BRINGING A CHANCE FOR STRONG THUNDERSTORMS TOMORROW. IN THE MEAN
TIME, MOIST SOUTHERLY LOW LEVEL FLOW HAS COMMENCED ACROSS THE REGION
AS SURFACE FRONTOGENESIS OCCURS TO OUR NORTH UNDER UPPER DIVERGENCE
FROM A DEPARTING POLAR JET MAX MOVING OFF THE ATLANTIC COAST AND
A DEVELOPING UPPER TROUGH OVER THE PLAINS. IN SPITE OF CONSIDERABLE
CLOUDINESS, THE WAA REGIME HAS ALLOWED TEMPS TO RISE WELL INTO THE
60S OVER THE SOUTHERN 2/3RDS OF THE CWA. DEWPOINT RECOVERY HAS BEEN A
BIT SLOWER, WITH 20S LINGERING IN THE NE, BUT UPPER 40S/LOW 50S
BEGINNING TO WORK INTO THE SOUTH. A FEW SPECKS OF REFLECTIVITY HAVE
BEEN NOTED ON RADAR THROUGH THE DAY, BUT DUE TO THE LOW LEVEL DRY
AIR, THESE SHOWERS ARE NOT LIKELY REACHING THE GROUND YET, AND INDEED
VIRGA WAS NOTED OUTSIDE AT OUR OFFICE THIS AFTERNOON.

AIRMASS RECOVERY WILL CONTINUE TONIGHT AS THE SURFACE FRONT SINKS
SOUTHWARD TO JUST NORTH OF THE CWA BY MORNING. A SURFACE LOW WILL
DEVELOP OVER THE RED RIVER VALLEY TONIGHT AND MOVE EASTWARD ALONG THE
FRONT INTO THE DELTA BY EARLY MONDAY AHEAD OF A POTENT SHORTWAVE
SWINGING INTO THE LOWER MS VALLEY. INITIALLY SHOWERS (AND SOME
ELEVATED STORMS) WILL BE MOSTLY CONFINED ALONG THE FRONT WITH
ACTIVITY ACROSS THE REMAINDER OF THE AREA MORE SCATTERED IN NATURE.
HEADING THROUGH MID TO LATE MORNING, ADDITIONAL DEVELOPMENT IS
EXPECTED FARTHER SOUTH/EAST ACROSS THE REMAINDER OF THE AREA ALONG A
PREFRONTAL TROUGH. BUFR SOUNDINGS INDICATE SBCAPE UP TO 1000 J/KG UP
TO AROUND THE I-20 CORRIDOR WITH 3-8 DECAMETER MID LEVEL HEIGHT FALLS
AND STEEPENING MID LEVEL LAPSE RATES ON THE ORDER OF 6.5 - 7 C/KM.
SREF AND NCAR ENSEMBLE MEAN MUCAPE SHOW THE MAIN CORRIDOR OF
INSTABILITY GENERALLY ALONG AND SOUTH OF I-20 (MAYBE SLIGHTLY FARTHER
NORTH TO THE EAST OF I-55). GIVEN THE LIMITED WINDOW OF MOISTURE
RETURN, GUIDANCE CONSENSUS CONTINUES TO KEEP LOWER 60S DEWPOINTS
CONFINED TO THE HWY 84/98 CORRIDORS WITH THIS SYSTEM. ANOTHER
POTENTIAL LIMITING FACTOR IN THE 12Z GUIDANCE WAS SOMEWHAT LESSER
DEEP LAYER SHEAR DURING THE TIME MAIN TIME WINDOW FOR CONVECTION
(LATE MORNING - AFTERNOON) AND AMBIENT SRH DECREASING DURING THIS
TIME FRAME. SO FOR NOW, WE WILL MAINTAIN A LIMITED SEVERE THREAT IN
THE HWO MAINLY FOR SEVERE HAIL AND DAMAGING WIND GUSTS. A TORNADO
CANNOT BE ENTIRELY RULED OUT WITH THIS SYSTEM, MAINLY IN THE
SOUTHEAST, BUT RIGHT NOW I BELIEVE THE BEST OVERLAY OF SHEAR AND
INSTABILITY WILL BE OUTSIDE OF THE CWA. RAIN WILL END QUICKLY MONDAY
EVENING AS THE FRONT PUSHES THROUGH, BUT WRAPAROUND CLOUDS MAY LINGER
OVERNIGHT AS THE UPPER TROUGH REMAINS NEARBY.

ONCE WE GET PAST THE MONDAY SYSTEM, THE WORK WEEK IS LOOKING DRY AND
WARMER. A SECONDARY SHORTWAVE ROUNDING THE EAST COAST UPPER TROUGH
WILL BRING A WEAK REINFORCING FRONT THROUGH THE AREA TUESDAY, BUT
DEEP LAYER MOISTURE WILL BE LIMITED AND THUS POPS WERE AGAIN KEPT
OUT OF THE FORECAST. THROUGH THE REST OF THE WEEK A HIGH AMPLITUDE
UPPER TROUGH WILL TRANSIT THE COUNTRY WITH HIGH PRESSURE BUILDING IN
AT THE SURFACE. TEMPS WILL MODERATE THROUGH THE END OF THE WEEK, WITH
HIGHS REACHING THE 70S ACROSS MUCH OF THE AREA BY THE WEEKEND. A
SERIES OF SHORTWAVES MOVING ACROSS THE MIDWEST WILL DRAG A COLD FRONT
TOWARD THE AREA THIS WEEKEND. WITH JET ENERGY REMAINING NORTH OF THE
AREA, THE FRONT WILL MAKE SLOW PROGRESS ACROSS THE AREA, BRINGING
RAIN CHANCES FROM LATE SATURDAY THROUGH SUNDAY. /DL/

&&

.AVIATION...CLOUDS WILL CONTINUE TO INCREASE FROM WEST TO EAST
ACROSS THE REGION TODAY BUT WILL REMAIN VFR. HOWEVER CEILINGS WILL
BEGIN TO DROP INTO THE MVFR RANGE AFTER MIDNIGHT TONIGHT AS A FRONT
APPROACHES THE REGION FROM THE NORTHWEST. THESE CEILINGS WILL REMAIN
MVFR TO IFR THROUGH MONDAY GIVEN INCREASING RAIN CHANCES. WINDS WILL
DIMINISH SLIGHTLY TONIGHT. SHOWERS AND SOME THUNDERSTORMS WILL
INCREASE FROM THE NORTHWEST TONIGHT ESPECIALLY AFTER MIDNIGHT.
SHOWERS AND STORMS WILL INCREASE MONDAY ALONG AND AHEAD OF A COLD
FRONT. SOME STORMS COULD BE STRONG TO SEVERE ACROSS THE AREA. STORMS
AND THE COLD FRONT SHOULD EXIT THE REGION AROUND 00Z TUESDAY. /28/

&&

.PRELIMINARY POINT TEMPS/POPS...
JACKSON       54  66  42  70 /  42  89  18   1
MERIDIAN      51  69  41  69 /  23 100  50   3
VICKSBURG     56  63  42  70 /  49  82  11   1
HATTIESBURG   54  71  45  72 /  30  85  49   1
NATCHEZ       56  66  44  71 /  46  80  12   1
GREENVILLE    53  57  40  66 /  76 100   8   2
GREENWOOD     53  60  39  67 /  67  99  12   3

&&

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

$$

DL/28


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