FXUS64 KMEG 041155
AFDMEG

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEMPHIS TN
555 AM CST FRI DEC 4 2009

.UPDATE...
UPDATED TO ADD 12Z AVIATION DISCUSSION.

&&

.PREV DISCUSSION... /ISSUED 418 AM CST FRI DEC 4 2009/ 

DISCUSSION...
EARLY MORNING GOES WATER VAPOR IMAGERY AND UPPER AIR ANALYSIS
SHOWED AN UNUSUALLY DEEP LONGWAVE UPPER LEVEL TROF EXTENDING FROM
HUDSONS BAY CANADA...SOUTH INTO FAR WEST TX. A SHORTWAVE WAS
DROPPING TOWARD THE BASE OF THE UPPER TROF...OVER EASTERN NM. THIS
SHORTWAVE WILL ROUND THE BASE OF THE LONGWAVE TROF AND EJECT INTO
THE LOWER MS RIVER VALLEY BY LATE EVENING. THIS WILL HELP DEEPEN
A SURFACE LOW ALONG THE COAST NEAR NEW ORLEANS. THE OOZ MODELS
KEEP THE BEST MOISTURE WELL SOUTH OF THE MIDSOUTH...NEARER TO THE
SURFACE LOW. WITH LIMITED MOISTURE AND THE OPEN AND PROGRESSIVE
NATURE OF THE SHORTWAVE...HAVE LOWERED POPS BY A FAIR MARGIN OVER
NORTH MS TONIGHT. NO SNOW ACCUMULATIONS ARE FORECAST FOR ANY
PORTION OF THE MIDSOUTH TONIGHT.

THE AFOREMENTIONED SYSTEM EJECT TO THE MIDATLANTIC SEABOARD BY
SATURDAY EVENING...LEAVING ZONAL FLOW AND SUNNY SKIES IN PLACE
OVER THE MIDSOUTH. BY THIS TIME... THE NEXT UPPER LEVEL LOW WILL
BE DIGGING SOUTH OVER THE CENTRAL ROCKIES...POISED TO EJECT INTO
THE MID MS RIVER VALLEY SUNDAY NIGHT. WILL CARRY CHANCE POPS WITH
THIS SYSTEM...BUT LOW QPF GIVEN THE LOW AMPLITUDE NATURE OF THE
MIDLEVEL WAVE AND INITIALLY DRY AIRMASS. 

A MUCH DEEPER UPPER LEVEL TROF WILL DIG INTO THE CENTRAL PLAINS BY
TUESDAY EVENING. LOW LEVEL RETURN FLOW AHEAD OF THIS SYSTEM WILL
RESULT IN MILDER TEMPS OVER THE MIDSOUTH...ESPECIALLY FOR MORNING
LOWS. RAIN SHOULD BEGIN LATE TUESDAY AFTERNOON AND PERSIST UNTIL
THE DRY SLOT EDGES IN ON WEDNESDAY. BY THE TIME SUBFREEZING TEMPS
OCCUR WEDNESDAY NIGHT...MOISTURE SHOULD BE WELL OFF TO THE EAST.

ZONAL FLOW AND A DRY AIRMASS SHOULD RESULT IN MODERATING AFTERNOON
TEMPERATURES LATE IN THE WEEK. MORNING LOWS WILL STILL BE QUITE
CHILLY.

PWB

&&

.AVIATION...
12Z TAF CYCLE

VFR CONDITIONS EXPECTED OVER THE NEXT 24 HOURS. MID/HIGH CLOUDS
ASSOCIATED WITH UPPER LEVEL TROUGH WILL MOVE OVER TAF SITES
THROUGH 05/03Z. NORTHWEST WINDS AROUND 7 KTS TODAY WILL
DECREASE TO AROUND 3-4 KTS BY 05/00Z.

CJC 

&&

.PRELIMINARY POINT TEMPS/POPS...
MEM  43  31  48  29 /   0  10   0   0 
MKL  42  21  46  21 /   0  10   0   0 
JBR  43  26  46  24 /   0  10   0   0 
TUP  42  29  48  24 /  10  10   0   0 

&&

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

$$