FXUS64 KMEG 241051
AFDMEG
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEMPHIS TN
451 AM CST THU DEC 24 2009
.UPDATE...
UPDATED FOR 12Z AVIATION DISCUSSION
&&
.PREV DISCUSSION... /ISSUED 323 AM CST THU DEC 24 2009/
DISCUSSION...
TODAY THROUGH CHRISTMAS DAY...A POTENTIAL FOR A BIT OF EVERYTHING
WEATHER AND WATER WISE DURING THE NEXT 30 TO 36 HOURS.
HEAVY RAIN...WILL CONTINUE THE FLASH FLOOD WATCH FOR NORTHEAST AR
AND THE MO BOOTHEEL THROUGH THIS AFTERNOON. MODERATE TO HEAVY
RAINFALL WILL CONTINUE IN THE WATCH AREA. THE SURFACE COLD FRONT
BACK IN EAST TEXAS DOES NOT BEGIN ITS EASTWARD ACCELERATION UNTIL
AFTER 12Z. AN ADDITIONAL TWO TO AS MUCH AS FOUR INCHES OF QPF IS
POSSIBLE.
HIGH WINDS...EXTENDED THE WIND ADVISORY UNTIL 09Z CHRISTMAS DAY
BASED ON 00Z MODEL TRENDS. THE TIGHTENING SURFACE PRESSURE
GRADIENT WILL ALLOW SOUTHEAST WINDS TO INCREASE TO 25 TO 35 MPH
WITH GUSTS TO 45 MPH. LEFT THE HIGH WIND WATCH IN PLACE DUE TO THE
50-60 KNOTS WINDS AT 925 MB LEVEL. IF THESE WINDS MIX DOWN TO THE
SURFACE AT TIMES LATER TODAY AND TONIGHT...WILL NEED A HIGH WIND
WARNING.
STRONG THUNDERSTORMS...EXPECT A SQUALL LINE TO CONSOLIDATE AROUND
12Z IN WESTERN LA AND PUSH RAPIDLY TO THE EAST DURING THE DAY. THE
SURFACE LOW WILL BEGIN TO OCCLUDE AROUND MIDDAY WHICH SHOULD CUT
OFF THE MINIMAL INSTABILITY POTENTIAL FOR EAST CENTRAL AR AND
NORTH CENTRAL MS. WILL HAVE TO WATCH FOR NORTHERN EXTENT OF STRONG
THUNDERSTORM POTENTIAL.
WINTER WEATHER...00Z MODELS HAVE THE SURFACE LOW FARTHER SOUTH AND
EAST THAN IN PREVIOUS RUNS. THIS ALLOWS DEFORMATION ZONE
PRECIPITATION TO DEVELOP ACROSS THE NORTHERN HALF OF THE MID SOUTH
TONIGHT AND EARLY CHRISTMAS DAY. 850 MB TEMPERATURES DROP ALMOST
20 DEGREES CELSIUS IN A 12 HOUR TIME FRAME. IT APPEARS SNOW WILL
MIX WITH RAIN AFTER MIDNIGHT. A LIGHT ACCUMULATION OF SNOW IS
POSSIBLE NORTH AND WEST OF LINE FROM WYNNE AR TO MARTIN TN.
FRIDAY NIGHT THROUGH SUNDAY...A STACKED UPPER LEVEL AND SURFACE LOW
OVER IOWA IS SLOW TO PROGRESS EAST. WILL HAVE TO WATCH THE
SOUTHWARD EXTENT OF CLOUDS AND LIGHT PRECIPITATION ROTATING AROUND
THE LOW.
MONDAY AND TUESDAY...DRY AND SEASONABLY COLD WEATHER IS FORECAST
WITH SURFACE HIGH PRESSURE PASSING OVERHEAD.
TUESDAY NIGHT AND WEDNESDAY...AN H5 UPPER LEVEL TROUGH IS FORECAST
TO MOVE INTO THE CENTRAL U.S. AND TAP GULF MOISTURE. LEFT THE
EXISTING FORECAST IN PLACE.
OKULSKI
.AVIATION...
12Z TAF CYCLE.
LOWEST CIGS WILL BE LIFR...WITH TEMPO VLIFR AT KJBR AS THIS SITE
WILL TAKE THE BRUNT OF THE PRECIPITATION TODAY. OTHER SITES WILL
MAINLY BE BACK AND FORTH WITH MVFR AND VFR CONDITIONS THIS
MORNING...THEN DECREASING TO MVFR AND TEMPORARY IFR CONDITIONS
THIS AFTERNOON. BEST CHANCE FOR THUNDER ON STATION WILL BE JUST
AHEAD OF THE COLD FRONT THIS AFTERNOON...EXTENDING INTO THE
EVENING HOURS AT KTUP. SOUTHEAST WINDS WILL CONTINUE TO INCREASE
TO 20 TO 35 KNOTS. HOWEVER...KJBR WILL SEE MORE OF AN EASTERLY
DIRECTION THROUGHOUT THE FIRST HALF OF THE TAF PERIOD. LOW LEVEL
WIND SHEAR WILL ALSO REMAIN A PROBLEM WITH 55-60 KNOTS FROM THE
SOUTH SOUTHEAST AT 1.5KFT. COLD FRONT WILL PASS THROUGH THE
REGION LATE THIS AFTERNOON AT KJBR...AND KMEM...AND EARLY THIS
EVENING AT KMKL...AND KTUP. THIS WILL SHIFT WINDS TO A MORE
SOUTHERLY DIRECTION...AND EVENTUALLY SOUTHWEST LATER IN THE TAF
PERIOD. SPEEDS WILL REMAIN STRONG HOWEVER...WITH GUSTS OF 25-35
KNOTS THROUGH 25/12Z.
RAIN WILL SLOWER TAPER OFF FROM WEST TO EAST AFTER 03Z...WITH
MAINLY MVRF CIGS. SOMEWHAT CONFIDENT THAT COLD AIR BEHIND THE
STORM WILL BRING A LIGHT RAIN AND SNOW MIX FOR ALL SITES EXCEPT
KTUP NEAR END OF TAF PERIOD...VISIBILITIES RANGING FROM 3-5 MILES.
JAB
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 57 33 39 28 / 100 80 20 10
MKL 58 34 37 25 / 100 90 20 10
JBR 53 32 36 24 / 100 90 20 10
TUP 62 36 41 27 / 100 90 20 10
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI-
PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
HIGH WIND WATCH FROM NOON CST TODAY THROUGH THIS EVENING FOR
CLAY-CRAIGHEAD-CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-
MISSISSIPPI-PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
WIND ADVISORY UNTIL 3 AM CST FRIDAY FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI-
PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR DUNKLIN-PEMISCOT.
HIGH WIND WATCH FROM NOON CST TODAY THROUGH THIS EVENING FOR
DUNKLIN-PEMISCOT.
WIND ADVISORY UNTIL 3 AM CST FRIDAY FOR DUNKLIN-PEMISCOT.
MS...HIGH WIND WATCH FROM NOON CST TODAY THROUGH THIS EVENING FOR
ALCORN-BENTON MS-CALHOUN-CHICKASAW-COAHOMA-DESOTO-ITAWAMBA-
LAFAYETTE-LEE MS-MARSHALL-MONROE-PANOLA-PONTOTOC-PRENTISS-
QUITMAN-TALLAHATCHIE-TATE-TIPPAH-TISHOMINGO-TUNICA-UNION-
YALOBUSHA.
WIND ADVISORY UNTIL 3 AM CST FRIDAY FOR ALCORN-BENTON MS-CALHOUN-
CHICKASAW-COAHOMA-DESOTO-ITAWAMBA-LAFAYETTE-LEE MS-MARSHALL-
MONROE-PANOLA-PONTOTOC-PRENTISS-QUITMAN-TALLAHATCHIE-TATE-
TIPPAH-TISHOMINGO-TUNICA-UNION-YALOBUSHA.
TN...HIGH WIND WATCH FROM NOON CST TODAY THROUGH THIS EVENING FOR
CARROLL-CHESTER-CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-
HARDEMAN-HARDIN-HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-
MADISON-MCNAIRY-OBION-SHELBY-TIPTON-WEAKLEY.
WIND ADVISORY UNTIL 3 AM CST FRIDAY FOR CARROLL-CHESTER-CROCKETT-
DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN-HARDIN-HAYWOOD-
HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON-MCNAIRY-OBION-
SHELBY-TIPTON-WEAKLEY.
&&
$$
