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000
FXUS64 KLZK 162329 AAA
AFDLZK

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LITTLE ROCK AR
629 PM CDT THU MAY 16 2013

.AVIATION...
THROUGH THE PERIOD...THE UPPER LEVEL LOW OVER NORTHERN ARKANSAS
WILL CONTINUE TO BE THE DOMINANT FEATURE...WITH ABUNDANT MOISTURE
PRESENT AT ALL LEVELS. RAIN WILL BE LIKELY THROUGH MUCH OF THE
NIGHT...GRADUALLY TAPERING OFF DURING THE DAY FRIDAY. MVFR AND IFR
CONDITIONS WILL REMAIN PREDOMINANT AT ADF...HOT...HRO...AND BPK...
WITH VFR CONDITIONS GRADUALLY DETERIORATING ELSEWHERE THROUGH THE
EVENING. CONDITIONS WILL IMPROVE DURING THE MORNING FRIDAY...BUT
WITH THE UPPER LOW STILL NEAR...CLOUDS AND ASSOCIATED MVFR
CONDITIONS ARE LIKELY TO REMAIN IN MUCH OF THE AREA THROUGH THE
END OF THE PERIOD. TAFS OUT ALREADY.
&&

.PREV DISCUSSION... /ISSUED 235 PM CDT THU MAY 16 2013/

DISCUSSION...

MAIN CONCERNS THIS FORECAST CYCLE ARE CONVECTION CHANCES TODAY
THROUGH FRIDAY WITH THE CURRENT UPPER SYSTEM...AND ANY RISK OF
STRONG TO SEVERE STORMS. THEN LOWER CHANCE ON SATURDAY BEFORE THE
UPPER RIDGE BUILDS IN. THEN COLD FRONT MID NEXT WEEK WITH
CONVECTION. TEMP FORECAST THROUGH THE PERIOD AROUND NORMAL VALUES
TO WARM UP OVER THE WEEKEND.

AFTERNOON CONVECTION HAS REMAINED LOW OVER AR...WITH THE UPPER LOW
PRESSURE SYSTEM OVER EASTERN OK AND MOVING EAST. EARLIER ENERGY
SPOKE AND CONVECTION OVER CENTRAL AR HAS MOVED NE. WHILE THE NEXT
SPOKE ROTATING AROUND THE UPPER LOW HAS DEVELOPED CONVECTION OVER
NE TX TO SW AR TO NW LA...WHICH WAS MOVING EAST SOUTH EAST.
STRONGEST PART OF THIS COMPLEX HAS MOVED OVER NE TX TO NW LA AND
HAS CUT OFF SOME ADDITIONAL POTENTIAL FOR AR STORMS. MAINLY HAVE
SEEN SHOWERS OVER AR EARLIER...WHILE THIS AFTERNOON...A BIT MORE
ELEVATED INSTABILITY HAS DEVELOPED WITH MORE THUNDER IN THE SW AR
AND SOUTH CONVECTION AREAS. THIS AREA IS EXPECTED TO CONTINUE TO
MOVE E SE AND AFFECT SOUTHERN AR. SPC HAS SOUTHERN AR IN SLIGHT
RISK OF SEVERE STORMS THIS AFTERNOON AND EVENING...ESPECIALLY IF
STORMS CAN BECOME MORE SURFACE BASED AND MORE INSTABILITY CAN
ADVECT NORTHWARD. HAVE SEEN SOME SHORT BUT HEAVY RAINFALL WITH
SOME STORMS OVER AR WHILE 12Z KZLK SOUNDING HAD A PRECIP WATER
VALUE OF 1.46 INCHES...AND DEW POINT TEMPS IN THE 60S. CLOUD COVER
HAS HELPED KEEP INSTABILITY DOWN THIS AFTERNOON...BUT IF
DIFFERENTIAL HEATING CAN TAKE HOLD...STORMS COULD INTENSITY
QUICKLY. LARGE HAIL AND/OR DAMAGING WINDS WOULD BE LIKELY SEVERE
THREAT IF ANY SEVERE STORMS FORM.

SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT

WILL KEEP FIRST PERIOD POPS HIGH...ESPECIALLY FROM CENTRAL TO
SOUTHERN AR...AS THE UPPER LOW MOVES OVER AR...AND BASED ON
CURRENT RADAR TRENDS. MODELS TRENDS GRADUALLY MOVE THE UPPER LOW
THROUGH AR TONIGHT AND WILL KEEP POP CHANCES HIGH THROUGH 12Z
FRIDAY. ON FRIDAY...POP CHANCES WILL GRADUALLY LOWER THROUGH THE
DAY FROM WEST TO EAST...BUT NOT END UNTIL FRIDAY NIGHT...AS MODELS
WANT TO HOLD JUST A BIT OF UPPER ENERGY AND WITH AN UPPER NW
FLOW...OVER AR. THEREFORE ALL RAIN CHANCES FINALLY END BY SATURDAY
AM. ON SATURDAY MODELS AGAIN HINT AT SOME WEAK SHORT WAVE ENERGY
IN THE NW UPPER FLOW...BEFORE THE UPPER RIDGE BUILDS IN OVER AR.
DUE TO HEATING TO THE 80S...IN PLACE MOISTURE AND SOME
INSTABILITY...HAVE A SILENT 14% POP GOING. WOULD NOT BE SURPRISED
IF AN ISOLATED STORM DOES DEVELOP SATURDAY...BUT WILL KEEP SILENT
AT THIS TIME. ON SUNDAY...A WARM AND HUMID DAY WILL BE SEEN WITH
AGAIN A SILENT POP GOING AT THIS TIME. AS MENTIONED...TEMPS WILL
BE NEAR NORMAL VALUES FRIDAY...THEN WARM TO THE 80S WITH SOME
LOCATIONS NEAR 90 ON SUNDAY.

LONG TERM...MONDAY THROUGH THURSDAY

AN UPPER LEVEL LOW WILL BE OVER THE NORTHERN PLAINS TO BEGIN THE
EXTENDED PERIOD WITH A RIDGE OVER THE EAST COAST. THE UPPER LOW WILL
NOT MOVE MUCH THROUGH WEDNESDAY. A WEAK TROUGH THEN DEVELOPS OVER
THE SOUTHERN PLAINS THURSDAY.

A COLD FRONT WILL EXTEND FROM THE MIDWEST THROUGH TEXAS AT THE
BEGINNING OF THE PERIOD. MODELS ARE INDICATING THIS FRONT WILL MOVE
THROUGH ARKANSAS ON TUESDAY AND POSSIBLY STALL UNTIL WEDNESDAY
BEFORE MOVING OUT OF THE STATE. THIS WILL BRING SHOWERS AND
THUNDERSTORMS TO THE AREA AND THE POSSIBILITY OF SOME SEVERE
THUNDERSTORMS. POPS WILL DECREASE WEDNESDAY. THE WEAK UPPER TROUGH
ON THURSDAY WILL BRING A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS.
TEMPERATURES WILL GENERALLY BE NEAR TO ABOVE NORMAL THROUGH THE
PERIOD.
&&

.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&

$$

AVIATION...57