Area Forecast Discussion
Issued by NWS Jackson, MS

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FXUS64 KJAN 301610 AAA
AFDJAN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON MS
1010 AM CST FRI JAN 30 2015

.UPDATE...THE SKY HAS CLEARED ACROSS MOST OF THE AREA...THOUGH HIGH
CLOUDS SPILLING OVER AN UPPER RIDGE WILL PASS OVERHEAD AT TIMES
THROUGHOUT THE DAY. WEAK COLD ADVECTION CONTINUES ACROSS THE CWA...
BUT WITH CONSIDERABLE SUNSHINE TEMPS ARE STILL ON TARGET TO RISE
INTO THE 50S ACROSS THE AREA. FOR THE UPDATE...WILL BUMP UP HIGH
TEMPS FOR TODAY 2-3 DEGREES IN A FEW AREAS BASED ON CURRENT TRENDS.
NO OTHER ADJUSTMENTS ARE NEEDED AT THIS TIME. /DL/

&&

.AVIATION...WITH HIGH CLOUDS STREAMING SOUTHEAST THROUGH THE
REGION...VFR CONDITIONS WILL CONTINUE TO PREVAIL ACROSS THE FORECAST
AREA. 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. /17/

&&

.DISCUSSION...

THROUGH SATURDAY NIGHT...

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/

&&

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

&&

$$

DL/17/19/EC




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