739
FXUS64 KMEG 130440
AFDMEG
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEMPHIS TN
1140 PM CDT MON AUG 12 2013
.UPDATE...
UPDATED FOR 06Z AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 1134 PM CDT MON AUG 12 2013/
.UPDATE...
.UPDATE TO LOWER POPS AND CANCEL FLASH FLOOD WATCH FOR THE
REMAINDER OF TONIGHT.
DISCUSSION...
CONVECTIVE COLD POOL WAS SUFFICIENTLY STRONG ENOUGH TO DRIVE
CONVECTION ALL THE WAY ACROSS THE ENTIRE CWA AND INTO THE NORTHERN
GULF STATES LATE THIS EVENING. THE AIRMASS TO THE NORTH OF THIS
CONVECTIVE OUTFLOW IS BEGINNING TO RECOVER ALREADY WITH A RETURN
TO LIGHT SOUTHERLY FLOW AND DEWPOINTS RISING BACK INTO THE LOWER
70S. EARLIER CONVECTION HAS STABILIZED THE ATMOSPHERE SUFFICIENTLY
THOUGH TO KEEP MOST AREAS RAIN FREE FOR THE NEXT SEVERAL HOURS.
WITH THIS IN MIND...HAVE CANCELLED THE FLASH FLOOD WATCH FOR THE
REMAINDER OF TONIGHT AS THE SHORT TERM THREAT FOR HEAVY RAINFALL
HAS ENDED.
A COLD FRONT REMAINS POSITIONED ACROSS SOUTH CENTRAL MISSOURI INTO
SOUTHERN ILLINOIS LATE THIS EVENING. THIS FRONT WILL SLOWLY
PROGRESS SOUTHWARD FOR THE REMAINDER OF TONIGHT INTO TUESDAY. AN
UPSTREAM SHORTWAVE NOTED OVER OKLAHOMA LATE THIS EVENING WILL
CONTINUE TO MOVE EAST AND WILL LIKELY INITIATE ADDITIONAL
CONVECTION LATE TONIGHT OVER ARKANSAS. THIS ACTIVITY WILL INCREASE
IN COVERAGE AND INTENSITY INTO TUESDAY MORNING AND OVERSPREAD MUCH
OF AT LEAST THE SOUTHERN HALF OF THE FORECAST AREA. THERE MAY BE
THE POTENTIAL FOR ADDITIONAL HEAVY RAINFALL WITH THIS SYSTEM AND A
NEW FLASH FLOOD WATCH WILL NEED TO BE CONSIDERED FOR MAINLY THE
SOUTHERN HALF OF THE FORECAST AREA ON TUESDAY.
THE FORECAST HAS BEEN UPDATED AND NEW GRIDS...ZONES...AND HWO HAVE
BEEN SENT.
JLH
&&
.PREV DISCUSSION... /ISSUED 402 PM CDT MON AUG 12 2013/
DISCUSSION...
SHORT TERM /TODAY THROUGH THURSDAY/...THE WEATHER PATTERN IS GOING
TO CHANGE FINALLY. THE BOUNDARY THAT HAS AFFECTED OUR AREA FOR THE
LAST SEVERAL DAYS HAS PUSHED NORTH AND SLIGHTLY WEST. WIDESPREAD
CONVECTION IS CURRENTLY TAKING PLACE ALONG THIS FRONT THIS
AFTERNOON WHICH IS BEING AIDED BY A SHORTWAVE PUSHING THE
CONVECTION EAST INTO OUR AREA. THE ZONAL FLOW ALOFT WILL FINALLY
BEGIN TO SHIFT TO A MORE PROGRESSIVE NORTHWESTERLY COMPONENT THIS
EVENING...AS A LOW PRESSURE SYSTEM OVER THE NORTHERN GREAT LAKES
WILL BEGIN TO TRACK SOUTH. THE NORTHWEST FLOW WILL ALLOW A SERIES
OF SHORTWAVES TO MOVE THROUGH OUR AREA TOMORROW. AS THE LONGWAVE
TROF DIGS DEEPER ON TUESDAY NIGHT INTO WEDNESDAY...A COLD FRONT IS
EXPECTED TO PUSH ALL THE WAY THROUGH OUR REGION. TIMING OF THE
FRONT WILL BE ON WEDNESDAY LATE AFTERNOON INTO THE EVENING WITH
THE COOLEST AIR MOVING IN OVERNIGHT INTO THURSDAY MORNING. EXPECT
TEMPERATURES TO BE SEASONABLY COOL WITH HIGHS ONLY IN THE MID TO
UPPER 80S.
AS THIS LINE OF STORMS MOVES THROUGH THIS EVENING...AREAS THAT HAVE
RECEIVED LARGE AMOUNTS OF PRECIPITATION TODAY AND YESTERDAY MAY
NEED A FLOOD WATCH/ADVISORY.
LONG TERM /FRIDAY THROUGH MONDAY/...FRIDAY WILL BE ANOTHER NICE
COOL AND DRY DAY. STARTING ON SATURDAY...MODELS HAVE BEEN HINTING
AT A CUTOFF LOW DEVELOPING FROM THE LONGWAVE TROF ON SATURDAY. IF
THIS HAPPENS...WE WILL REMAIN IN A COOL AND WET PATTERN FOR THE
WEEKEND AND AND INTO THROUGH EARLY NEXT WEEK. NOT A LOT OF
CONFIDENCE IN THIS SCENARIO THOUGH...AS MODELS ALWAYS HAVE A
DIFFICULT TIME WITH THIS TYPE OF PATTERN.
AC3
&&
.AVIATION...
06Z TAF CYCLE
CONVECTION CONTINUES TO QUICKLY WANE NEAR TUP...WITH CLOUDS THINNING
FURTHER NORTH. IN THE SHORT TERM CONDITIONS WILL BE VFR...BUT
EXPECTING LIGHT FOG AND STRATUS TO DEVELOP BEFORE 12Z WITH TEMPO
MVFR CONDITIONS AT ALL SITES. AFTER 13/12Z A COLD FRONT CURRENTLY
ACROSS MISSOURI WILL BEGIN TO TRACK SOUTH THROUGH THE TAF
SITES...WITH SHOWERS INCREASING BY LATE MORNING AS IT REACHES MEM
AND THUNDERSTORMS BY EARLY AFTERNOON AS IT REACHES TUP. SO HAVE
PLACED TEMPOS IN ACCORDINGLY.
WINDS WILL BE LIGHT FROM THE SOUTHWEST AND WEST TONIGHT...VEERING
FROM THE NORTH AND NORTHEAST AT 7-10 KTS BEHIND THE FRONT.
JAB
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 72 88 70 85 / 30 50 50 50
MKL 69 89 68 84 / 20 50 50 40
JBR 72 88 68 83 / 30 50 30 30
TUP 72 91 70 87 / 30 50 50 50
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$