Area Forecast Discussion
Issued by NWS Jackson, MS

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FXUS64 KJAN 301108
AFDJAN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
508 AM CST FRI JAN 30 2015

.DISCUSSION...

TODAY THROUGH SATURDAY NIGHT...

COLD ADVECTION WILL BE ONGOING ACROSS THE FORECAST AREA TODAY AS
SURFACE HIGH PRESSURE CENTERED NORTH OF THE REGION BUILDS INTO THE
FORECAST AREA DURING THE COURSE OF THE DAY. STRATUS ASSOCIATED WITH
THE MID/UPPER LEVEL TROUGH SWINGING THROUGH THE TENNESSEE AND OHIO
RIVER VALLEYS WILL CONTINUE TO SKIRT NORTHEAST MISSISSIPPI THIS
MORNING. AS THE TROUGH CONTINUES ITS EASTWARD PUSH...STRATUS WILL
CLEAR THIS AREA LATER THIS MORNING. OTHERWISE...LOOK FOR MOSTLY SUNNY
SKIES THIS AFTERNOON WITH ONLY SOME HIGH CLOUDS RACING SOUTHEAST
ACROSS THE CWA. HIGHS THIS AFTERNOON WILL TOP OUT IN THE 50S.

MOISTURE ALOFT WILL BE ON THE SUBTLE INCREASE TONIGHT AS THE BEFORE
MENTIONED SURFACE HIGH NOW RESIDES NORTHEAST OF THE REGION.  A
GRADUAL INCREASE IN CLOUDS IS EXPECTED EARLY SATURDAY MORNING.  LOOK
FOR LOWS TONIGHT TO RANGE FROM THE UPPER 20S IN THE NORTHEAST TO THE
MIDDLE 30S ACROSS MY SOUTHWEST.

WEAK MID/UPPER RIDGING WILL BUILD ACROSS THE REGION SATURDAY AND
SATURDAY NIGHT.  CLOUDS WILL ALSO INCREASE DURING THE PERIOD WITH
SLIGHTLY WARMER CONDITIONS EXPECTED.  LOOK FOR PARTLY CLOUDY SKIES
SATURDAY AFTERNOON WITH HIGHS RANGING FROM THE MID 50S TO LOWER 60S.

WEST SOUTHWEST FLOW ALOFT WILL INCREASE AHEAD OF A NORTHERN STREAM
SHORTWAVE BEGINNING TO SWING EAST ACROSS THE NATION`S MID-SECTION.
THIS...IN ADDITION TO LOW LEVEL MOISTURE INCREASING ACROSS THE
FORECAST AREA...WILL IN TURN RESULT IN INCREASING RAIN CHANCES ACROSS
THE FORECAST AREA FROM WEST TO EAST LATE SATURDAY NIGHT INTO EARLY
SUNDAY MORNING. UNDER CLOUDY SKIES...LOWS SATURDAY NIGHT WILL RANGE
FROM THE LOWER 40S TO LOWER 50S. /19/

SUNDAY THROUGH NEXT FRIDAY...

IT LOOKS LIKE THUNDERSTORM POTENTIAL COULD BE ON THE INCREASE
SUNDAY AHEAD OF A STRENGTHENING COLD FRONT. AFTER TRENDING HIGHER
WITH SURFACE PRESSURES OVER THE LOWER MS VALLEY REGION AND MORE
SUPPRESSED WITH THE WARM SECTOR...ALL GUIDANCE IS NOW IN CONSENSUS
FOR GREATER NORTHERN STREAM AMPLIFICATION AIDED BY INTERACTION
WITH THE SOUTHWEST CONUS TROUGH...AND THIS SHOULD RESULT IN SFC LOW
DEVELOPMENT OVER THE MID MS/OH VALLEYS. THIS NORMALLY COULD SPELL
TROUBLE IN TERMS OF SEVERE WEATHER POTENTIAL GIVEN FAVORABLE FORECAST
HODOGRAPHS...BUT UNDERWHELMING MOISTURE RETURN IS EXPECTED TO RESULT
IN POOR LOW-MID LEVEL LAPSE RATES THAT SHOULD MAKE IT TOUGH TO GET
MUCH DEEP CONVECTION.

SO THAT THERE ARE NO SURPRISES...IT SHOULD BE NOTED THAT WITH
IMPROVED SAMPLING OF THE NRN STREAM SHORTWAVE TROUGH...GUIDANCE MAY
CONTINUE TO TREND MORE AMPLIFIED AND PRONOUNCED WITH MOISTURE RETURN.
AS IT STANDS THE GFS/ECMWF SHOW ROUGHLY 100-300 J/KG MOST UNSTABLE
CAPE AND WEAKLY NEGATIVE SFC LI WITH SFC DEWPOINTS APPROACHING 60 DEG
F ALONG THE HWY 84 CORRIDOR. MOREOVER...CIPS GUIDANCE ANALOGS FOR
THIS EVENT INDICATE AT LEAST A VERY LOW POTENTIAL FOR SEVERE
WEATHER...PARTICULARLY FROM NE LA INTO WEST CENTRAL MS WHERE MODELS
HAVE BEEN SIGNALING FOR THE GREATEST FRONTAL FORCING MATCHED UP WITH
BETTER INSTABILITY SUNDAY AFTN. FOR NOW...SEVERE PROBS ARE TOO LOW TO
WARRANT A MENTION IN HWO/ GRAPHICS AT THIS POINT AND HAVE JUST ADDED
THUNDER TO THE OFFICIAL FORECAST...BUT WILL NEED TO MONITOR TRENDS.

GREATER AMPLIFICATION OF THE TROUGH COULD ALSO DRAW COLDER AIR
SOUTHWARD SUNDAY NIGHT INTO MONDAY. WOULD NOT BE SURPRISED TO SEE A
FEW LOCATIONS ALONG THE HIGHWAY 82 CORRIDOR EXPERIENCE MARGINAL HARD
FREEZE CRITERIA IN THE MON-TUES TIME FRAME..BUT FOR THE MOST PART
JUST EXPECT A TYPICAL MID-WINTER COLD SNAP WITH HIGHS STRUGGLING TO
REACH THE UPPER 30S TO MID 40S MONDAY AFTERNOON WHILE LOWS DIP WELL
INTO THE 20S MONDAY NIGHT.

LOOKING AHEAD TO MID/LATE NEXT WEEK...GUIDANCE IS FAIRLY CONSISTENT
IN SHOWING THAT THE CUTOFF LOW OVER THE SOUTHWEST CONUS WILL KICK OUT
AND DEVELOP A LOW PRESSURE SYSTEM OVER THE NORTHERN GULF OF MEXICO
WHILE ANOTHER SURGE OF VERY CHILLY AIR SURGES SOUTH THROUGH THE
CENTRAL/EASTERN CONUS. AS HAS BEEN CONSISTENTLY INDICATED...MODELS DO
NOT LINK THE SYSTEM/COLD AIR UP IN TIME TO SUPPORT WINTRY PRECIP IN
THE ARKLAMISS...SO EXPECT THIS WILL BE AN ALL RAIN EVENT IF THE
TRENDS CONTINUE. THERE IS QUITE A BIT OF INCONSISTENCY AND MODEL
SPREAD IN JUST HOW MUCH COLD AIR MOVES BEHIND THE SYSTEM LATE IN
THE WEEK...BUT THE COLD HAS THE POTENTIAL TO BE HIGHLY ANOMALOUS.
/EC/

&&

.AVIATION...WITH HIGH CLOUDS STREAMING SOUTHEAST THROUGH THE REGION
AND STRATUS AFFECTING NORTHEAST MISSISSIPPI THIS MORNING...VFR
CONDITIONS WILL CONTINUE TO PREVAIL ACROSS THE FORECAST AREA.
STRATUS IS EXPECTED TO CLEAR EAST AND OUT OF NORTHEAST MISSISSIPPI
LATER THIS MORNING...BUT CIRRUS WILL CONTINUE TO RACE SOUTHEAST
OVERHEAD THROUGH MUCH OF THE DAY.  WINDS TODAY WILL BE NORTHERLY
AROUND 10 KNOTS...WITH A FEW HIGHER GUSTS POSSIBLE THROUGH EARLY
AFTERNOON.  WINDS WILL SUBSIDE LATER THIS AFTERNOON...AND BECOME
MORE NORTHEASTERLY AROUND 5 KNOTS OVERNIGHT INTO EARLY SATURDAY
MORNING. /19/

&&

.PRELIMINARY POINT TEMPS/POPS...
JACKSON       55  31  59  45 /   0   0   7  39
MERIDIAN      55  27  56  41 /   0   0   5  25
VICKSBURG     55  33  59  48 /   0   0   7  51
HATTIESBURG   58  31  60  46 /   0   0   6  24
NATCHEZ       55  34  59  51 /   0   0   8  50
GREENVILLE    50  30  55  45 /   0   0   7  45
GREENWOOD     51  28  56  45 /   0   0   6  44

&&

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

&&

$$

19/EC/





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