FXUS64 KMEG 101144 AAA
AFDMEG

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MEMPHIS TN
544 AM CST THU DEC 10 2009

.UPDATE...
UPDATED FOR AVIATION.

&&

.PREV DISCUSSION... /ISSUED 447 AM CST THU DEC 10 2009/ 

DISCUSSION...10Z SURFACE ANALYSIS THIS MORNING PLACES A 979 MB
STRONG SURFACE LOW OVER WESTERN QUEBEC WHILE 1024 MB HIGH PRESSURE
WAS BRINGING PRECIPITATION FREE WEATHER TO THE PLAINS AND
MISSISSIPPI VALLEY THIS MORNING. A VERY COLD ARCTIC AIRMASS IN
PLACE ACROSS THESE AREAS HAS RESULTED IN TEMPERATURES BELOW ZERO
NEAR THE UNITED STATES/CANADIAN BORDER TO THE CENTRAL PLAINS AND
SINGLE DIGITS ABOVE ZERO TO THE TEENS ACROSS MISSOURI AND OKLAHOMA
AS OF 4 AM CST. TEMPERATURES THROUGH TONIGHT AND PRECIPITATION
CHANCES THIS WEEKEND INTO EARLY NEXT WEEK ARE THE MAIN CHALLENGES
IN THIS MORNING/S FORECAST PACKAGE. 

COLD ARCTIC HIGH PRESSURE WILL REMAIN IN PLACE ACROSS THE LOWER
MISSISSIPPI VALLEY TODAY THROUGH FRIDAY. HIGH TEMPERATURES TODAY
ARE EXPECTED TO BE IN THE 30S NORTH OF I-40 AND STRUGGLE TO REACH
40 DEGREES ACROSS NORTH MISSISSIPPI. COLD ARCTIC HIGH PRESSURE IS
EXPECTED TO BE DIRECTLY OVERHEAD ACROSS THE FORECAST AREA
TONIGHT...BRINGING THE COLDEST AIR OF THE SEASON TO THE MID SOUTH
THUS FAR. TEMPERATURES TONIGHT WILL RANGE FROM THE TEENS NORTH TO
THE LOWER 20S ACROSS NORTH MISSISSIPPI. WENT WITH TEMPERATURES AT
OR BELOW MET GUIDANCE FOR THE SHORT TERM AS MAV GUIDANCE SEEMS TO
BE TOO WARM GIVEN THE CURRENT PATTERN.

WRF/GFS SHORT TERM MODELS CONTINUE TO INDICATE A SURFACE LOW
DEVELOPING IN THE NORTHERN GULF OF MEXICO FRIDAY THEN MOVING ALONG
THE COAST THROUGH SUNDAY. THIS WILL PRODUCE SOME OVERRUNNING
PRECIPITATION ACROSS THE LOWER MISSISSIPPI VALLEY. ANALYSIS OF
MODEL SOUNDINGS AND 00Z WRF/GFS/ECMWF DATA SUGGEST BEST
PRECIPITATION CHANCES WILL REMAIN WELL SOUTH OF THE AREA FRIDAY
NIGHT AND KEPT SLIGHT CHANCE POPS GOING FOR NOW AS LOW LEVEL DRY
AIR WILL STILL BE IN PLACE. RAIN IS EXPECTED TO OVERSPREAD THE ENTIRE
FORECAST AREA SATURDAY THEN GRADUALLY TAPER OFF ON SUNDAY WITH THE
BEST RAIN CHANCES ACROSS NORTHEAST MISSISSIPPI.

LATEST 00Z GFS/ECMWF LONG RANGE MODELS INDICATE ANOTHER COLD FRONT
MOVING THROUGH THE AREA MONDAY NIGHT INTO TUESDAY BUT KEPT POPS AT
LOW END CHANCE FOR NOW DUE TO MODEL RUN TO RUN CONTINUITY PROBLEMS
OVER THE PAST FEW DAYS. 

CJC

&&

.AVIATION...
12Z TAFS

FEW AVIATION WEATHER CONCERNS THROUGH THE NEXT 24 HOURS...WITH 
VERY DRY AND COLD ARCTIC AIRMASS REMAINING OVER THE MIDSOUTH. THE
CENTER OF THE ARCTIC HIGH PRESSURE WILL MOVE FROM A 12Z POSITION 
OVER NORTHEAST OK....TO DIRECTLY OVER THE MIDSOUTH BY EARLY EVENING.
NORTHWEST SURFACE WINDS WILL GO CALM OVER THE MIDSOUTH TAF SITES
NEAR OR SHORTLY AFTER SUNSET.

PWB

&&

.PRELIMINARY POINT TEMPS/POPS...
MEM  38  23  46  32 /   0   0  10  10 
MKL  35  17  42  26 /   0   0  10  10 
JBR  35  19  41  27 /   0   0  10  10 
TUP  40  23  46  32 /   0   0  10  20 

&&

.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&

$$