000
FXUS64 KMEG 221733
AFDMEG

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEMPHIS TN
1233 PM CDT WED MAY 22 2013

.UPDATE...
UPDATED FOR 18Z AVIATION DISCUSSION.

&&

.PREV DISCUSSION... /ISSUED 1019 AM CDT WED MAY 22 2013/

UPDATE...MORNING UPDATE.

DISCUSSION...
ADJUSTED POPS A BIT...TRENDING DOWN. HAVE DOUBTS AS TO HOW MUCH
REDEVELOPMENT WE WILL SEE THIS AFTERNOON. THE FIRST OF A SERIES OF
2 COLD FRONTS IS MOVING INTO EAST ARKANSAS AND WILL CONTINUE TO
MOVE EAST ACROSS THE MIDSOUTH...INTO CENTRAL TENNESSEE AND NORTH
ALABAMA THIS AFTERNOON. ANY PRECIPITATION WOULD DEVELOP AHEAD OF
THIS FEATURE. THE 12Z NASHVILLE SOUNDING IS STRONGLY CAPPED...IT
WOULD TAKE TEMPERATURES VERY CLOSE...MAYBE A DEGREE OR TWO WARMER
THAN OUT WEST TN FORECAST HIGHS TO OVERCOME THE CAP. HIGHS SHOULD
TOP OUT IN THE LOWER 80S.

&&

.PREV DISCUSSION... /ISSUED 647 AM CDT WED MAY 22 2013/

DISCUSSION...09Z SURFACE ANALYSIS PLACES A SURFACE LOW OVER
EASTERN IOWA WITH A TRAILING COLD FRONT EXTENDING SOUTH ACROSS
MISSOURI...ARKANSAS...AND NORTHEAST TEXAS. KNQA WSR-88D RADAR
TRENDS SHOW THE BACK EDGE OF LAST NIGHT/S CONVECTIVE LINE OF
SHOWERS AND THUNDERSTORMS LOCATED JUST EAST OF THE TENNESSEE RIVER
AND INTO ALABAMA EARLY THIS MORNING. TEMPERATURES AS OF 4 AM CDT
ARE IN THE LOWER TO MIDDLE 60S AT MOST LOCATIONS. PRECIPITATION
CHANCES FOR TODAY THROUGH THURSDAY AND AGAIN FOR LATE THIS WEEKEND
INTO EARLY NEXT WEEK ARE THE PRIMARY FORECAST CHALLENGES THIS
MORNING.

SHORT TERM...(TODAY THROUGH FRIDAY)...SHORT TERM MODELS INDICATE
THE COLD FRONT CURRENTLY LOCATED WEST OF THE MISSISSIPPI RIVER
WILL GRADUALLY MOVE EAST ACROSS THE MID SOUTH TODAY. WATER VAPOR
SATELLITE/UPPER AIR PROFILER TRENDS INDICATE ANOTHER SHORTWAVE
EMBEDDED WITHIN THE UPPER LEVEL TROUGH OVER THE OKLAHOMA PANHANDLE
THIS MORNING. THIS UPPER LEVEL SHORTWAVE AND THE COLD FRONT MAY
RESULT IN THE DEVELOPMENT OF SCATTERED SHOWERS AND THUNDERSTORMS
ACROSS THE MID SOUTH TODAY AND ANY RESIDUAL CHANCES EAST OF THE
MISSISSIPPI RIVER THIS AFTERNOON AS INDICATED BY THE LATEST RUC
AND HRRR. UNTIL THE FRONT PASSES THROUGH THE MID SOUTH...A SMALL
POTENTIAL WILL EXIST FOR PERHAPS A STRONG THUNDERSTORM OR TWO OVER
NORTHEAST MISSISSIPPI THIS AFTERNOON AS INSTABILITY INCREASES UP
TO 2000 J/KG AND 700-500 MB LAYER MID LEVEL LAPSE RATES BECOME
MODERATELY STEEP.

ANOTHER MID LEVEL SHORTWAVE TROUGH AND ASSOCIATED COLD FRONT IS
EXPECTED TO MOVE THROUGH THE MID SOUTH ON THURSDAY. AT THIS
TIME...THINK A POTENTIAL FOR ISOLATED THUNDERSTORMS WILL BE
CONFINED MAINLY TO AREAS ALONG THE TENNESSEE RIVER THURSDAY
AFTERNOON. COOLER AND DRIER AIR IS EXPECTED TO BUILD INTO THE MID
SOUTH FOR THURSDAY NIGHT AND FRIDAY WITH LOWS THURSDAY NIGHT IN
THE 50S AND HIGHS ON FRIDAY IN THE 70S.

LONG TERM...(SATURDAY THROUGH TUESDAY)...00Z GFS/ECMWF LONG TERM
MODEL RUNS INDICATE CONTINUE TO DISAGREE FOR THE UPCOMING WEEKEND
INTO EARLY NEXT WEEK AS A WARM FRONT DEVELOPS ACROSS THE LOWER
MISSISSIPPI VALLEY AND A SUBSEQUENT UPPER LEVEL RIDGE BUILDS ACROSS THE
REGION EARLY NEXT WEEK. RECENT ECMWF MODEL RUNS INDICATE THE FRONT
BECOMING QUASI-STATIONARY ACROSS THE MIDDLE/LOWER MISSISSIPPI
VALLEYS AND THE TENNESSEE VALLEY SUNDAY INTO MONDAY WHILE THE GFS
PLACES THE FRONT ACROSS THE UPPER MIDWEST/NORTHERN MISSOURI DURING
THIS TIME FRAME. THE ECMWF SOLUTION SUGGESTS SEVERAL CHANCES FOR
SHOWERS AND THUNDERSTORMS OVER THE MEMORIAL DAY WEEKEND ARE
POSSIBLE BUT HAVE LEANED THE FORECAST TOWARDS THE OPERATIONAL GFS
WHICH HAS THE SUPPORT OF THE GFS ENSEMBLE MEMBERS. CONSEQUENTLY...WILL
CONTINUE TO KEEP FORECAST DRY FOR NOW UNTIL MODELS COME INTO
BETTER AGREEMENT. A RETURN OF MIDDLE TO UPPER 80 TEMPERATURES ARE
EXPECTED ACROSS THE MID SOUTH FOR SUNDAY THROUGH EARLY NEXT WEEK.

CJC

&&

.AVIATION...
18Z TAFS

PREDOMINATELY VFR THIS PERIOD WITH THE EXCEPTION OF BOTH PATCHY
MVFR CIGS EAST OF THE MS RIVER FROM A FEW AFTERNOON SHOWERS...AND
LIGHT FOG NEAR SUNRISE. AS SKIES BECOME MOSTLY CLEAR TONIGHT
SOUTHWEST WINDS OF 10-15 KTS WILL DIMINISH TO 3-6 KTS. WINDS WILL
VEER NORTHWEST AND INCREASE TO 8-12 KTS LATE THURSDAY MORNING.

JAB

&&

.PRELIMINARY POINT TEMPS/POPS...
MEM  81  63  83  57 /  30  10  10  10
MKL  82  59  80  51 /  40  10  20  10
JBR  81  59  81  53 /  20  10  10  10
TUP  81  60  84  58 /  50  10  10  10

&&

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

$$