FXUS64 KMEG 300217
AFDMEG
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEMPHIS TN
817 PM CST SUN NOV 29 2009
.UPDATE...01Z SURFACE ANALYSIS THIS EVENING PLACES A COLD FRONT
FROM CAPE GIRARDEAU MISSOURI THEN BACK THROUGH LITTLE ROCK AND
TEXARKANA. REGIONAL WSR-88D RADAR TRENDS SHOW SHOWERS WITH
EMBEDDED /ELEVATED/ THUNDERSTORMS LOCATED MAINLY ALONG THE FRONT.
THUNDERSTORM ACTIVITY IS EXPECTED TO REMAIN MAINLY ACROSS EAST
ARKANSAS /SOUTH OF I-40/ AND NORTH MISSISSIPPI THIS EVENING.
VISIBILITIES DUE TO EARLIER FOG/DRIZZLE ARE GRADUALLY IMPROVING AS
CONVECTIVE ACTIVITY INCREASES ACROSS THE FORECAST AREA.
LATEST SHORT TERM MODELS INDICATE FRONTAL PASSAGE WILL OCCUR
THIS EVENING WEST OF THE MISSISSIPPI RIVER AND OVERNIGHT ACROSS
THE REMAINDER OF THE FORECAST AREA. WILL ISSUE AN UPDATE TO EXPAND
MENTION OF ISOLATED THUNDERSTORMS ACROSS THE REMAINDER OF NORTH
MISSISSIPPI THIS EVENING AND TO ADJUST WEATHER ELEMENTS AS NEEDED
BASED ON CURRENT TRENDS.
UPDATED GRIDS WILL BE PUBLISHED SHORTLY.
CJC
&&
.PREV DISCUSSION... /ISSUED 555 PM CST SUN NOV 29 2009/
UPDATE...
UPDATED AVIATION DISCUSSION FOR 00Z TAFS.
DISCUSSION...
/ISSUED 229 PM CST SUN NOV 29 2009/
INCLEMENT WEEK AHEAD FOR THE MIDSOUTH AS H5 CUTOFF LOW DRIFTS
SLOWLY ACROSS TEXAS...THEN LIFTS OUT AS THE NORTHERN BRANCH OF THE
PFJ DIGS SOUTH FROM THE NORTHERN PLAINS.
TONIGHT COLD FRONT ELONGATED FROM SOUTHERN GREAT LAKES TO CENTRAL
TEXAS WILL PASS THROUGH THE MIDSOUTH. BAND OF PRECIPITATION WILL
BE MAINLY BEHIND THE FRONT AS UPPER LEVEL FLOW BECOMES MORE
PARALLEL. ALL MODELS HINTING THAT PRECIPITATION WILL LINGER OVER
THE REGION MONDAY MORNING WITH THE ECMWF BEING THE SLOWEST. SO
KEPT POPS IN FOR THE ENTIRE CWA THROUGH 18Z...THEN JUST A SLIGHT
CHANCE FOR THE EASTERN THIRD AFTER 18Z. MONDAY EVENING CLOUDS WILL
CLEAR OVER THE AREA AS SURFACE HIGH PRESSURE BUILDS IN FROM THE
WEST. FELT ENOUGH CONFIDENCE FOR PATCHY FOG TUESDAY MORNING AS
CENTER OF THE HIGH PASSES OVER THE REGION. THE REST OF TUESDAY
LOOKS TO BE ABOVE NORMAL AS WINDS SHIFT TO THE SOUTH. HOWEVER
CLOUDS WILL CREEP BACK INTO THE AREA TUESDAY NIGHT AS TEXAS LOW
APPROACHES. MODELS ARE SLIGHTLY DIFFERENT ON SURFACE LOW
DEVELOPING OVER NORTHWEST GULF AND TRACKING NORTHEAST. GFS TAKES
THE TRACK THE FURTHEST EAST ACROSS ALABAMA...THEN ALONG THE
BACKBONE OF THE APPALACHIANS. THE ECMWF BRINGS IT THROUGH NORTHERN
MISSISSIPPI...THEN SHUNTS IT QUICKLY NORTHEAST TO LINE IT UP WITH
THE GFS IN WEST VIRGINIA BY THURSDAY. THE NAM SOLUTION BASICALLY SPLITS
THE TWO TRACKS. CHOSE MORE OF THE ECMWF SOLUTION BASED ON PAST TRENDS.
THIS WILL MEAN MORE PRECIPITATION WILL BE LIKELY OVER THE MIDSOUTH
ON WEDNESDAY AND WEDNESDAY NIGHT. ONE ITEM IN WHICH THE MODELS ARE
IN AGREEMENT ABOUT IS THE ARCTIC AIR DIVING SOUTH BEHIND THE STORM.
H850 TEMPS LIKELY TO DROP FROM ZERO TO -8 FROM WEDNESDAY NIGHT
INTO THURSDAY MORNING. ECMWF LINGERS PRECIPITATION ACROSS THE
MIDSOUTH THURSDAY MORNING BEFORE H5 TROUGH AXIS MOVES THROUGH.
THIS SEEMS REASONABLE...THEREFORE RAIN MAY BE MIXED WITH SNOW LATE
WEDNESDAY NIGHT THROUGH NOON ON THURSDAY. FUTURE MODEL RUNS WILL
NEED TO MONITORED CLOSELY AS TO ANY CHANGES TO THE POTENTIAL OF A
WINTRY WEATHER MIX THURSDAY MORNING.
LATE THURSDAY THROUGH FRIDAY APPEARS TO BE DRY AND COLD...WITH
ONLY A SLIGHT WARM UP EXPECTED ON SATURDAY AND SUNDAY. NEXT
SYSTEM WILL BRING CLOUDS AND A CHANCE OF PRECIPITATION TO THE
REGION LATE NEXT WEEKEND AND INTO EARLY NEXT WEEK.
JAB
AVIATION...
00Z TAFS
AT KMEM...LIFR CONDITIONS WILL LIKELY IMPROVE TO IFR AROUND 02Z ONCE
RA MOVES IN FROM THE WEST. IMPROVEMENT TO MVFR CONDITIONS CAN BE
EXPECTED ONCE COLD FRONT MOVES THROUGH AROUND 04Z...THOUGH WOULD
NOT BE SURPRISED IF IFR CONDITIONS HELD ON UNTIL 06Z. KEPT RA IN
FORECAST AND DID NOT MENTION VCTS THINKING ANY TS WILL REMAIN
SOUTH OF THE SITE. NORTH WINDS 10-15 KTS CAN BE EXPECTED BEHIND
COLD FRONT AFTER 04Z WHICH MAY GUST UP TO 20 KTS 04-10Z. RA WILL
END 07-09Z...THEN IMPROVEMENT TO VFR CAN BE EXPECTED 13-18Z.
AT KJBR...KMKL...AND KTUP...LIFR CONDITIONS AT KMKL WILL LIKELY
IMPROVE TO IFR ONCE RA BEGINS 03-04Z. IFR CONDITIONS CAN BE
EXPECTED THROUGH 02Z AT KJBR AND 05Z AT KMKL BEFORE IMPROVING TO
MVFR BEHIND COLD FRONT PASSAGE. BELIEVE MVFR CONDITIONS AT KTUP
WILL BECOME IFR 05-08Z WITH RA AND VCTS NEARBY...THOUGH IFR
CONDITIONS MAY ARRIVE AS EARLY AS 02Z. NORTH WINDS 9-13 KTS CAN BE
EXPECTED BEHIND COLD FRONT. RA WILL END WEST TO EAST AS EARLY AS
05Z AT KJBR TO AROUND 14Z AT KTUP. MVFR CONDITIONS WILL IMPROVE TO
VFR 12-15Z AT KJBR...16-19Z AT KMKL...AND 18-22Z AT KTUP.
MBS
&&
.AVIATION...
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 46 52 38 61 / 100 50 0 10
MKL 43 50 32 59 / 100 50 0 10
JBR 42 51 32 57 / 100 30 0 10
TUP 48 53 35 59 / 100 70 10 10
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
