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000
FXUS64 KJAN 100405 AAB
AFDJAN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON MS
1005 PM CST TUE FEB 9 2010

.DISCUSSION...NO FURTHER CHANGES NEEDED TO THE PACKAGE WITH MINOR
TWEEK OF HOURLY DEWPOINTS IN THE DIGITAL/GRAPHICS ALREADY SENT.
TEMPS RUNNING 30-34F ACROSS MOST OF CWFA AND SHOULD HAVE NO PROBLEM
REALIZING OVERNIGHT LOWS AS PWATS NEAR 0.11 INCHES ALLOW CLEAR SKY
AND LIGHT WINDS TO CONTINUE LONGWAVE RADIATION PROCESSES. UPSTREAM
THIN HIGH LEVEL CLOUDS RACING INTO THE RIO GRANDE VALLEY WILL EASILY
PUSH BACK INTO OUR REGION TOWARD MORNING BUT HAVE LITTLE IMPACT ON
THE COOLING BOUNDARY LAYER.

IN REGARD TO UPCOMING SNOWS...LATEST SREF/UKMET SOLUTIONS SUPPORTING
CURRENT SCENARIO ALTHOUGH SREF TRYING TO PUSH ACCUMULATIONS TOO FAR
N FROM WHERE BEST MOISTURE AND -2C 850MB TEMPS LOCATED. WOULD STILL
EXPECT MAX SNOW BAND ROUGHLY ALONG A WINNSBORO, LA TO MENDENHALL TO
SHUBUTA LINE AND ABOUT A 60SM WIDE SWATH OR SO./40/

&&

PREV DISCUSSION... /ISSUED 230 PM CST TUE FEB 9 2010/

SHORT TERM...TONIGHT THROUGH THURSDAY...IT WILL BE A COLD NIGHT AS
ALL SITES WILL BOTTOM OUT IN THE 20S. NORTHWEST WINDS ALOFT WILL
SLOWLY BACK TO THE WEST WEDNESDAY WHILE THE SURFACE HIGH SHIFTS EAST
OVER OUR REGION. THIS WILL CONTRIBUTE TO DRY CONDITIONS WEDNESDAY AND
MILDER TEMPERATURES. HOWEVER...TEMPERATURES WILL REMAIN 10 TO 15
DEGREES BELOW SEASONAL AVERAGES...WITH HIGHS IN THE 40S. WINDS ALOFT
WILL CONTINUE BACKING WEDNESDAY NIGHT AHEAD OF A CLOSED LOW THAT WILL
BE MOVING OVER SE ARIZONA/SW NEW MEXICO BY THURSDAY MORNING. THIS
WILL BRING AN INCREASE IN HIGH LEVEL CLOUDS WEDNESDAY NIGHT BUT
TEMPERATURES SHOULD HAVE NO PROBLEM DROPPING INTO THE 20S AGAIN AT
MOST LOCATIONS. COME THURSDAY...THE SURFACE HIGH IS EXPECTED TO BE
CENTERED OVER THE TENNESSEE VALLEY WHICH WILL KEEP COOL DRY
CONDITIONS GOING OVER OUR REGION AS WEAK CAA CONTINUES. ATOP THIS
AIRMASS WAA WILL BE INCREASING AHEAD OF THE APPROACHING UPPER LEVEL
LOW OVER WEST TEXAS AND THE DEVELOPING SURFACE LOW OVER THE SOUTHEAST
TEXAS COAST. THIS WILL RESULT IN A THICKENING AND LOWERING MID LEVEL
CLOUD DECK FROM THE SOUTHWEST. THE INCREASING CLOUDS WILL LIMIT
INSOLATION AND HOLD TEMPERATURES WELL BELOW NORMAL AGAIN. PWS WILL
START OFF BELOW A HALF INCH AND IT WILL TAKE SOME TIME TO MOISTEN THE
COLUMN ENOUGH TO GET MEASURABLE PRECIPITATION AT THE SURFACE.
STILL...MODELS SUGGEST SOME PRECIPITATION OVER THE WESTERN TWO THIRDS
OF THE BY LATE THURSDAY AFTERNOON. MODEL SOUNDINGS SUGGESTS A MIX OF
LIGHT RAIN AND LIGHT SLEET WILL BE POSSIBLE. SURFACE TEMPERATURES
WILL BE ABOVE FREEZING THURSDAY AFTERNOON SO NO WINTRY MIX
ACCUMULATIONS ARE EXPECTED. GUIDANCE TEMPERATURES WERE REMARKABLY
CLOSE THROUGH THURSDAY AT MOST SITES BUT HAVE GONE A FEW DEGREES
BELOW MAX TEMPERATURES THURSDAY. THE FORECAST GETS A LITTLE TOUGHER
GOING INTO THURSDAY NIGHT AS THEY DIVERGE ON THE EVOLUTION AND
POSITIONS OF THE CLOSED LOW AND SURFACE LOW. THE OPERATIONAL GFS
APPEARS TO BE THE OUTLIER IN SUFFERING SOME CONVECTIVE FEEDBACK AND
TAKING THE SURFACE LOW EAST SOUTHEAST TOWARD THE FLORIDA STRAITS. THE
ECMWF HAS SUPPORT FROM THE UKMET AND CANADIAN. FOLLOWING THIS
SCENARIO...A SIGNIFICANT SNOWFALL EVENT FOR THE ARKLAMISS STILL LOOKS
ON TRACK FOR THURSDAY NIGHT INTO FRIDAY. THE PREVIOUS DISCUSSION
HANDLES THIS BELOW. /22/

LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...THE FOCUS OF THIS
FORECAST IS ON THE POTENTIAL HEAVY SNOW EVENT FOR THU NIGHT INTO THE
FIRST HALF OF FRI. ASIDE FROM THAT...TEMPS WILL BE THE OTHER FOCUS.

THE MAIN EVENT/PRECIP WINDOW WILL BE THU NIGHT INTO THE FIRST HALF
OF FRI. THE LATEST MODEL DATA IS NOT IN THE BEST OF AGREEMENT...BUT
SOME SIMILARITIES EXIST AND HAVE BEEN CARRIED FROM THE PREV RUNS.
THE LATEST WITH THE GFS IS THAT IT IS MORE SUPPRESSED. THE SFC LOW
IS FURTHER SOUTH AND AS A RESULT...THE BEST ASCENT AND PRECIP
GENERATION REGION IS FURTHER S CLOSER TO I-10. IN TURN...THE OVERALL
ATMOSPHERE IS A TAD COLDER WHICH LEADS TO INCREASED CONFIDENCE THAT
PRECIP TYPE WILL BE ALL SNOW AFTER THE INITIAL LIGHT SLEET MIX. THE
EURO IS SIMILAR TO ITS PREV RUNS...A BIT WETTER...AND CLOSE TO THE
EARLIER GFS RUNS. IT TO IS A TAD COLDER AND PAINTS A SNOWIER
PICTURE. THE SREF AND GFS ENSEMBLE DATA IS MORE OF A BLEND OF THE
EURO/GFS AND IS THE WAY I WILL BE LEANING. THE SREF IS SLOWER AND IT
HAS MORE OF A NAM FLAVOR. I DON`T LIKE THE REAL SLOW SOLUTION AS
THOSE ARE OUTLIERS...SO A SLIGHTLY SPED UP SREF FITS GOOD WITH A
BLEND OF THE EURO/GFS. THE MAIN TIMEFRAME WILL WILL FOCUS MEASURING
SNOW AND ANY ACCUMULATING SNOW WILL BE BETWEEN 9 PM AND 10 AM...WITH
SOME STILL POSSIBLE A FEW HRS EITHER SIDE OF MY PREDICTED WINDOW.

AT THIS TIME...BASED OFF THE RECENT TRENDS FROM PREV RUNS AND PAST
EVENTS...THE MAIN AREAS THAT I EXPECT TO SEE MEASURABLE SNOW WILL BE
FOR LOCATIONS ALONG AND S OF I-20 WITH THE BEST POTENTIAL WITH IN
THE HWY 84 CORRIDOR. AMOUNTS BETWEEN 2-4 INCHES SEEMS STILL A GOOD
FIRST GUESS WITH SOME LOCATIONS SEEING A BIT MORE.
ADDITIONALLY...THE FURTHER N YOU GO...LIMITED MOISTURE AND BEING A
BIT REMOVED FROM THE BEST ASCENT SHOULD ONLY YIELD AN INCH OR SO.
NOW...THIS IS JUST MY BEST GUESS BASED OFF THE PREV MODEL RUNS AND
TRENDS FROM THE LATEST DATA. THERE STILL SEEMS TO BE DECENT SPREAD
IN THE MODEL GUID AND WITH THE TRACK OF THE GULF LOW STILL QUITE
UNCERTAIN...EXPECT THINGS TO CHANGE SOME WITH EACH MODEL RUN. LETS
HOPE THAT WITH THE FEATURE OF INTEREST JUST NOW COMING ONSHORE IN
CENTRAL CA...THAT THE MODELS WILL QUICKLY PICK UP ON A SOLUTION AND
CONVERGE TO SOMETHING IN THE NEXT 24-36HRS.

ANOTHER PRIMARY FORECAST ISSUE FOR FRI IS TEMPS. FOR SOME
REASON...GUID TEMPS ARE VERY WARM FOR HIGHS WITH VALUES RANGING FROM
THE LOWER/UPPER 40S. I WILL BE CUTTING THOSE SIGNIFICANTLY. WITH THE
COMBINATION OF SNOWY PRECIP FALLING/LINGERING INTO MIDDAY AND THEN
CLOUDS LASTING THROUGH THE DAY ALONG WITH AT LEAST SOME WEAK
CAA...TEMPS SHOULD ONLY REACH THE MID/UPPER 30S AT BEST.

IN THE WAKE OF THE THU/FRI SYSTEM...SFC HIGH PRESSURE LOOKS TO
SETTLE OVER THE REGION FOR SAT/SAT NIGHT. BY SUN...ALL GUID IS
INDICATING A POTENT UPPER LOW WILL DIVE SE OUT OF THE N PLAINS AND
HELP TO CARVE OUT A FAIRLY LARGE E CONUS TROUGH FOR EARLY WEAK. AS
THIS OCCURS...A SOLID COLD FRONT WILL CROSS THE REGION SOMETIME LATE
SUN INTO EARLY MON AND RE-ENFORCE THE COLD CONDITIONS AND BELOW
NORMAL PATTERN. AS FOR TEMPS SAT-TUE...GUID VALUES WERE GENERALLY
GOOD AND ACCEPTED. THE ONLY MAJOR ADJ WAS TO WARM SUN HIGHS AS THE
00Z GFS WAS TOO QUICK WITH THE FROPA AND GOING WITH A SLOWER/WARMER
SOLUTION FIT BEST. /CME/

&&

.AVIATION...

LATEST SATELLITE IMAGERY SHOWS VFR CLEAR SKIES AND THOSE GUSTY NWLY
WINDS DIMINISHED TO 7-10KTS. WINDS WILL GRADUALLY COME AROUND TO NLY
BY WEDNESDAY MORNING AT 8KTS OR LESS. EXPECT VFR HIGH THIN CLOUDS FOR
WEDNESDAY SLOWLY BEGINNING TO LOWER SLOWLY WEDNESDAY NIGHT./40/

&&

.PRELIMINARY POINT TEMPS/POPS...
JACKSON       24  46  28  43 /   0   2   4  26
MERIDIAN      23  46  25  44 /   0   2   5  16
VICKSBURG     24  46  28  43 /   0   2  11  35
HATTIESBURG   25  50  29  48 /   0   2   7  19
NATCHEZ       25  46  28  43 /   0   2  13  47
GREENVILLE    24  42  25  41 /   0   2   5  25
GREENWOOD     23  43  25  41 /   0   2   4  19

&&

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

$$