FXUS64 KMEG 031136 AAA
AFDMEG
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MEMPHIS TN
536 AM CST THU DEC 3 2009
.UPDATE...
UPDATED FOR AVIATION.
&&
.PREV DISCUSSION... /ISSUED 443 AM CST THU DEC 3 2009/
DISCUSSION...FORECAST FOCUS ON CHILLY TEMPS FOR THE NEXT SEVERAL
DAYS...CHANCES OF SNOW IN MS FRIDAY NIGHT...THEN ON AN ACTIVE PATTERN
NEXT WEEK.
TODAY THROUGH FRIDAY...
AS OF 10Z...THE LOW PRESSURE THAT BROUGHT UNSETTLED CONDITIONS TO
THE MIDSOUTH ON WEDNESDAY HAS ALREADY PUSHED TO LAKE ONTARIO. HIGH
PRESSURE BUILDING INTO THE REGION TODAY WILL BRING CLEARING SKIES
TODAY AND UNSEASONABLY COOL TEMPERATURES. HIGHS TODAY SHOULD
REMAIN IN THE LOW 40S NORTH TO UPPER 40S SOUTH.
CLOUDS SHOULD INCREASE AGAIN TONIGHT THROUGH FRIDAY AS A SURGE OF
MID LEVEL MOISTURE STREAMS IN OVERHEAD. COUPLE THE CLOUDS WITH
CONTINUING COLD AIR ADVECTION WILL MAKE FOR AN UNSEASONABLY COLD
DAY WITH HIGHS ONLY IN THE UPPER 30S TO LOWER 40S.
FRIDAY NIGHT THROUGH SATURDAY NIGHT...
BY LATE FRIDAY AFTERNOON...LOW PRESSURE WILL BE DEVELOPING OVER
THE WESTERN GULF OF MEXICO AS AN UPPER LEVEL DISTURBANCE ROUNDS
THE BASE OF A RATHER LARGE LONG WAVE TROUGH. AS EXPECTED
YESTERDAY...THE ECMWF HAS FINALLY COME IN LINE WITH THE INITIAL
THINKING OF SPREADING LIGHT SNOW NORTHWARD INTO PORTIONS OF
NORTHERN MISSISSIPPI AS THE LOW PRESSURE TRACKS ACROSS THE GULF.
MUCH OF THE MOISTURE WILL REMAIN SOUTH OF THE CWA...BUT WILL
MAINTAIN THE CHANCE OF LIGHT SNOW AND SNOW ACCUMULATIONS UP TO A
HALF INCH. THIS IS QUITE AN UNUSUAL PATTERN AS EVEN THE TEXAS AND
LOUISIANA GULF COAST WILL LIKELY SEE SOME ACCUMULATING SNOW FRIDAY
NIGHT.
CLOUDS WILL HAMPER A RAPID DROP OFF OF TEMPERATURES FRIDAY
NIGHT...BUT SOME AREAS IN THE TENNESSEE RIVER VALLEY AND NORTHEAST
ARKANSAS COULD SEE LOWS DIP INTO THE TEENS. HIGH PRESSURE OVER THE
MIDSOUTH FOR SATURDAY WILL LEAD TO CLEAR SKIES...BUT CONTINUED
COLD TEMPERATURES. SATURDAY COULD BE THE COLDEST NIGHT OF THE NEXT
7 DAYS...ESPECIALLY IN THE TN RIVER VALLEY. LOWS IN THE MID TEENS
ARE NOT OUT OF THE QUESTION...BUT THE HIGH BEGINNING TO PUSH EAST
AND A RETURN FLOW SETTING UP MAY PREVENT IT FROM GETTING QUITE THAT
COLD.
SUNDAY THROUGH NEXT WEDNESDAY...
LOW PRESSURE DEVELOPING OVER THE SOUTHERN PLAINS SUNDAY AFTERNOON
WILL TRACK NORTHEAST INTO THE LOWER GREAT LAKES SUNDAY NIGHT AND
MONDAY MORNING. A TRAILING COLD FRONT WILL SWING THROUGH THE
MIDSOUTH DURING THAT TIME...LEADING TO A CHANCE OF PRECIP.
MOISTURE ACCESS REMAINS THE BIG QUESTION AFTER THE GULF HAS BEEN
CUT OFF FOR A COUPLE DAYS...SO KEPT POPS IN THE CHC CATEGORY FOR
NOW. ENOUGH COLD AIR MAY BE LEFT OVER ACROSS THE FAR NORTHERN CWA TO
SUPPORT A RAIN/SNOW MIX SUNDAY NIGHT. NO ACCUMULATIONS ARE EXPECTED.
THEN THE FORECAST GETS EVEN MORE COMPLICATED AS MIDWEEK NEXT WEEK
ROLLS AROUND. LOW PRESSURE WILL ONCE AGAIN DIVE SOUTHEAST INTO THE
SOUTHERN PLAINS TUESDAY NIGHT. MODELS HAVE BEEN A BIT INCONSISTENT
AS EXPECTED WITH THIS FEATURE. SOME MODELS SUCH AS THE ECMWF TAKE
IT ACROSS THE MIDSOUTH...WITH ENOUGH COLD AIR REMAINING TO THE
NORTH TO SUPPORT A WINTRY MIX ESPECIALLY ON THE BACKSIDE OF THE
LOW TUESDAY NIGHT. OTHER MODELS TAKE THIS STORM NORTH OF THE CWA
AND STRENGTHEN IT RAPIDLY AS IT TRACKS INTO THE GREAT LAKES OR THE
OHIO VALLEY. MANY DETAILS WILL NEED TO BE WORKED OUT BETWEEN NOW
AND THEN AND THE FORECAST IS LIKELY TO CHANGE...BUT IT APPEARS
PRECIP CHANCES WILL BE INCREASING BY EARLY TO MIDDLE NEXT WEEK.
AN ARCTIC AIRMASS IS PROGGED BY ALL OPERATIONAL MODELS TO SPILL
SOUTH BEHIND THE LOW...SO IT SHOULD GET RATHER CHILLY BY LATE NEXT
WEEK.
BORGHOFF
&&
.AVIATION...
12Z TAFS
MVFR CIGS WERE GRADUALLY DECREASING IN COVERAGE WHILE CLOUD BASES
WERE RISING TO 3KFT OR BETTER WEST OF THE MS RIVER...AS DRIER AIR
FILTERS IN FROM THE NORTHWEST.
A SURFACE PRESSURE SURGE CENTERED OVER THE MO BOOTHEEL AT DISCUSSION
TIME WAS HELPING INCREASE WINDS AT KMKL TO 12 KTS. THIS PRESSURE
SURGE SHOULD PASS BY 14Z OR 15Z...LEAVING 5 TO 8 KT WINDS ACROSS
THE MIDSOUTH. CIGS SHOULD GO VFR BY THIS TIME EAST OF THE MS RIVER...
LEAVING AREAWIDE LIGHT NORTHWEST WINDS AND VFR CONDITIONS THROUGH
THE REMAINDER OF THE VALID TAF PERIOD.
PWB
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 45 28 40 25 / 0 0 10 10
MKL 43 25 39 21 / 0 0 10 10
JBR 42 25 38 21 / 0 0 10 10
TUP 47 30 42 27 / 0 0 10 40
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
