000
FXUS64 KMEG 032147
AFDMEG
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEMPHIS TN
347 PM CST WED DEC 3 2008
.DISCUSSION...
RAPIDLY CHANGING WEATHER WILL OCCUR OVERNIGHT WITH SHOWERS TONIGHT
FOLLOWED BY A RETURN TO WINTER-LIKE TEMPERATURES THURSDAY. BELOW
NORMAL TEMPERATURES WILL PERSIST MUCH OF THE TIME INTO NEXT WEEK
WITH ANOTHER WET WEATHER SYSTEM AFFECTING THE AREA EARLY NEXT
WEEK.
AT MID-AFTERNOON...AN UPPER LEVEL SHORT WAVE WAS MOVING INTO TX.
MEANWHILE...A COLD FRONT STRETCHED FROM SOUTHERN IL ACROSS
SOUTHEAST MO THROUGH WESTERN AR AND INTO NORTHEAST TX. VERY COLD
AIR WAS LOCATED BEHIND THE FRONT WITH MID-AFTERNOON TEMPERATURES
IN THE 20S AND 30S THROUGHOUT MUCH OF THE NORTHERN AND CENTRAL
ROCKIES AND PLAINS STATES. THE SHORT WAVE TO OUR SOUTH IS
FORECAST TO MOVE INTO LA BY SUNRISE THURSDAY WITH THE COLD FRONT
TO OUR NORTH MOVING THROUGH THE MID-SOUTH OVERNIGHT. INCREASING
MOISTURE AND LIFT IN ASSOCIATION WITH THESE SYSTEMS WILL CAUSE
SHOWERS TO DEVELOP ACROSS ALL THE MID-SOUTH TONIGHT. THERE IS SOME
ELEVATED INSTABILITY FORECAST...THUS CAN NOT RULE OUT A FEW RUMBLES
OF THUNDER...BUT CONFIDENCE IS NOT HIGH ENOUGH TO MENTION IN THE
FORECAST AT THIS TIME. WINDS WILL SHIFT TO THE NORTH AND BECOME
STRONG AND GUSTY BEHIND THE FRONT...SO YOU WILL DEFINITELY KNOW
WHEN THE FRONT COMES THROUGH. WIND CHILL READINGS WILL BE NEAR 20
DEGREES FROM NORTHEAST AR INTO NORTHWEST TN BY DAYBREAK THURSDAY.
AREAS OF RAIN MAY LINGER ACROSS THE SOUTHEAST HALF OF THE AREA EARLY
THURSDAY MORNING...OTHERWISE SKIES WILL CLEAR FROM THE NORTHWEST
DURING THE DAY THURSDAY. TEMPERATURES WILL STRUGGLE TO CLIMB AT ALL
AS COLD HIGH PRESSURE BUILDS INTO THE AREA. BELOW NORMAL
TEMPERATURES WILL CONTINUE THROUGH FRIDAY NIGHT. FAVORED THE COLDER
MOS GUIDANCE FOR TEMPERATURES DUE TO THE LOW LEVEL COLD AIR
UPSTREAM. AN UPPER LEVEL THROUGH WILL MOVE ACROSS THE AREA FROM
THE NORTHWEST FRIDAY...BUT ONLY MID AND HIGH LEVEL CLOUDS ARE
EXPECTED.
WINDS WILL TURN TO THE SOUTHWEST SATURDAY WITH SOME WARMING BY
SATURDAY AFTERNOON. HOWEVER...ANOTHER COLD HIGH PRESSURE WILL
MOVE INTO THE AREA FROM THE NORTH SATURDAY NIGHT. BRIEF WARMING
WILL OCCUR BY MONDAY AS THE HIGH MOVES TO THE EAST. NO
PRECIPITATION IS FORECAST THROUGH THE DAY MONDAY...AFTER TOMORROW
MORNING.
MODELS INDICATE THE NEXT CHANCE OF SHOWERS WILL COME IN THE MONDAY
NIGHT THROUGH TUESDAY NIGHT TIMEFRAME. AN UPPER LEVEL TROUGH AND
ASSOCIATED COLD FRONT IS FORECAST TO AFFECT THE MID-SOUTH. THERE
ARE TIMING AND STRENGTH DIFFERENCES BETWEEN THE ECMWF AND GFS. FOR
NOW KEPT POPS IN THE CHANCE CATEGORY...BUT AS THE TIMING BECOMES
BETTER DEFINED IN LATER FORECASTS THESE POPS WILL NEED TO BE
RAISED IF PRESENT MODEL TRENDS CONTINUE. THE GFS INDICATES THAT
RAIN COULD CHANGE TO SNOW OVER NORTHERN AREAS TUESDAY NIGHT BEFORE
ENDING...HOWEVER CONFIDENCE ON THIS OCCURRING IS LOW SINCE THE GFS
IS OFTEN TOO STRONG WITH THE FORECAST SURFACE LOWS THAT FAR OUT IN
TIME.
JCL
&&
.AVIATION...
18Z TAF CYCLE
LLWS MAY OCCUR BRIEFLY AT MEM FOR A COUPLE OF HOURS THIS
AFTERNOON AS WINDS UP TO 3KFT ALREADY AROUND 50KTS. VFR CEILINGS
BETWEEN 3-6KFT WILL GRADUALLY LOWER TO MVFR CEILINGS THIS
AFTERNOON AS A COLD FRONT APPROACHES TAF SITES. RAIN EXPECTED TO
DEVELOP AFTER 21Z AT JBR AND SPREAD EAST TO TUP BY 02Z THEN END AT
JBR AROUND 12Z AND REMAINING SITES THROUGHOUT DAY THURSDAY. WINDS
WILL VEER SHARPLY AFTER PASSAGE OF COLD FRONT TONIGHT.
CJC
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 36 41 27 42 / 100 20 0 0
MKL 34 38 22 39 / 100 20 0 0
JBR 31 38 23 40 / 100 10 0 0
TUP 44 44 25 45 / 100 50 0 0
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
