000
FXUS64 KMEG 272135
AFDMEG
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEMPHIS TN
335 PM CST MON DEC 27 2010
.SYNOPSIS...
PATCH OF LOW CLOUDS IS SLOWLY ERODING OVER THE FAR NORTHEAST
PORTION OF OUR FORECAST AREA. TEMPERATURES ARE AROUND 10 DEGREES
BELOW AVERAGE DESPITE AFTERNOON SUNSHINE IN MOST AREAS.
&&
.SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT...
COLD AIRMASS AND HIGH PRESSURE FOR ONE MORE NIGHT ACROSS THE
MID-SOUTH. AS THE POLAR AIRMASS RETREATS THROUGH MID-WEEK...THE NEXT
WEATHER FEATURE IS A WEAK SHORTWAVE AND ATTENDANT WARM AIR ADVECTION
PATTERN THAT IS FORECAST TO MOVE INTO OUR REGION EARLY ON
WEDNESDAY. NAM/GFS CRITICAL THICKNESSES AND BUFKIT SOUNDINGS
SUGGEST LIQUID PRECIPITATION FOR THIS EVENT WITH NO FREEZING RAIN AT
THE ONSET. HAVE DECIDED TO TAKE OUT FREEZING RAIN IN THE
FORECAST.
BROAD ISENTROPIC LIFT CONTINUES INTO THURSDAY NIGHT WITH THE
POSSIBLY OF MORE RAIN/DRIZZLE. THERE ARE SOME MODEL DIFFERENCES ON
THURSDAY/THURSDAY NIGHT. THE GFS IS A LITTLE DRIER WHILE THE
NAM/GEM/ECMWF ARE MORE SUGGESTIVE OF THE POSSIBILITY OF RAINFALL.
A POLAR AIRMASS OF THIS MAGNITUDE IS TYPICALLY SLOW TO
LEAVE...THEREFORE WILL STICK WITH A MORE WET POSSIBILITY AND KEEP
SOME POPS.
.LONG TERM...FRIDAY THROUGH MONDAY...
GROWING EYE ON SEVERE POSSIBILITY FOR FRIDAY/FRIDAY NIGHT. DEEP
UPPER TROF SHIFTS TO THE WESTERN US WHICH ALLOWS FOR STRONG
SOUTHERLY FLOW ON FRIDAY. MODELS SUGGESTS 60 DEGREE DEW POINTS INTO
THE REGION BY 18Z...ALONG WITH STRONG 40-50KTS 850 MB WIND AND
MUCAPE IN THE 300/600 J/KG RANGE. TIMING OF FRONT WITH MAX
INSTABILITY IS EVERYTHING WITH THESE WINTERTIME EVENTS AND THE
ECMWF A BIT SLOWER THAN THE GFS. THE EVENT IS STILL FOUR DAYS OUT
AND THESE DETAILS ARE YET TO BE DETERMINED...BUT WILL CONTINUE TO
HIGHLIGHT THE POSSIBILITY OF SEVERE IN THE HWO.
FOR DAYS 6 AND 7 ALL MODELS DRY OUT THE REGION AND DROP TEMPERATURES
BACK TO NEAR AVERAGE.
BELLES
&&
.AVIATION...
18Z TAF CYCLE
HIGH PRESSURE OVER THE MIDSOUTH IS ALLOWING A PLEASANT WINTER DAY
TO PROCEED. SKIES ARE CLOUDY FROM BLYTHEVILLE TO JACKSONT TO
LEXINGTON...BUT THEY ARE ERODING NORTHEASTWARD ATTM. WINDS ARE
CALM TO LIGHT AND VARIABLE. CLEAR...CALM...COLD CONDITIONS ARE
EXPECTED TONIGHT. TUESDAY...WINDS WILL PICK UP OUT OF THE SOUTH
AGAIN.
WER
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 24 47 35 48 / 0 10 20 70
MKL 16 45 30 44 / 0 10 10 70
JBR 20 44 32 44 / 0 10 40 70
TUP 19 45 30 48 / 0 10 10 70
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
