Area Forecast Discussion
Issued by NWS Memphis, TN

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000
FXUS64 KMEG 282333
AFDMEG

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEMPHIS TN
633 PM CDT THU MAY 28 2015

.UPDATE...

UPDATED FOR THE 00Z AVIATION DISCUSSION

&&

.PREV DISCUSSION... /ISSUED 300 PM CDT THU MAY 28 2015/

DISCUSSION...

MAIN FORECAST CONCERNS THIS AFTERNOON REVOLVE AROUND THE EVOLUTION
OF THE MCV NOW ACROSS CENTRAL ARKANSAS...TRANSITIONING TO THE
PROLONGED PERIOD OF PRECIPITATION CHANCES THROUGH THE WEEKEND.

CURRENTLY...WEAK STEERING FLOW IS IN PLACE ACROSS THE MID-SOUTH AS
WEAK SHORTWAVE RIDGING IS PROGRESSING EAST. A REMNANT CIRCULATION
WAS MOVING THROUGH NORTHWEST ARKANSAS WITH A CONVERGENT AXIS
EXTENDING SOUTH-SOUTHEAST WHERE A LINE OF THUNDERSTORMS WAS
LOCATED. THESE STORMS ARE LARGELY DRIVEN BY INTERNAL COLD POOL
DYNAMICS AS VERY WEAK UPPER LEVEL FLOW IS LIMITING STORM
ORGANIZATION.

AS OF NOW...PURE EXTRAPOLATION OF THE LEADING EDGE OF THIS COMPLEX
WOULD BRING THUNDERSTORMS TO WESTERN PORTIONS OF THE CWA AFTER
00Z. THE AIRMASS AHEAD OF THIS COMPLEX IS UNCAPPED AND STRONGLY
UNSTABLE...SBCAPE VALUES AOA 2500 J/KG...SO OUTFLOW MOVING INTO
THIS ENVIRONMENT SHOULD CONTINUE TO INITIATE NEW CONVECTIVE
DEVELOPMENT. THE QUESTION IS HOW FAR EAST THIS CONTINUES. GIVEN
THE VERY WEAK WIND FIELDS/FORCING...BELIEVE THAT THIS ACTIVITY
WILL STRUGGLE TO MAKE IT TO THE MISSISSIPPI RIVER. A FEW
SHOWERS/ISOLATED THUNDERSTORMS ARE CERTAINLY POSSIBLE...BUT UNTIL
BETTER STORM ORGANIZATION OCCURS...CHANCES WILL BE KEPT LOW.

ON FRIDAY...A BETTER LARGE SCALE SIGNAL EXISTS FOR MORE WIDESPREAD
THUNDERSTORM ACTIVITY. A SHORTWAVE EJECTS INTO THE SOUTHERN PLAINS
DURING PEAK HEATING WHICH SHOULD ALLOW FOR MUCH GREATER COVERAGE
OF THUNDERSTORM ACTIVITY. WIND FIELDS CONTINUE TO BE WEAK BUT
INSTABILITY IS SUFFICIENT FOR A FEW STRONGER THUNDERSTORMS
POTENTIALLY PRODUCING ISOLATED DAMAGING WIND EVENTS ACROSS CENTRAL
AND EASTERN ARKANSAS. THUNDERSTORMS WILL AGAIN BE SLOW MOVING
WITH HEAVY RAIN POTENTIAL MAXIMIZED IN NEARLY STATIONARY
THUNDERSTORMS.

THROUGH THE WEEKEND...A FRONTAL BOUNDARY WILL SAG VERY SLOWLY
SOUTH ATTACHED TO A DEPARTING LOW PRESSURE SYSTEM IN THE
NORTHEAST. UPPER LEVEL FLOW WILL BECOME PARALLEL TO THIS FRONT
ALLOWING IT TO STALL FOR SEVERAL DAYS. PWATS BOTH DAYS WILL HOVER
BETWEEN 1.5 AND 2 INCHES...AND GIVEN THE SLOW MOVING NATURE TO THE
THUNDERSTORMS...ISOLATED FLASH FLOODING APPEARS POSSIBLE.

IN THE LONG TERM...THE SYNOPTIC FRONTAL BOUNDARY BEGINS TO WASH
OUT ACROSS THE MID-SOUTH. THUNDERSTORMS WILL BECOME TIED MORE TO
DIURNAL HEATING DURING THIS PERIOD WITH COVERAGE DECREASING
THROUGH MID-WEEK. IT ALSO APPEARS THAT HIGH TEMPERATURES WILL WARM
SLIGHTLY INTO THE MID AND UPPER 80S. IN SUMMARY...WARMER THAN
AVERAGE TEMPERATURES WITH ISOLATED THUNDERSTORMS WILL BE THE THEME
OF THE LONG-TERM PERIOD OF THE FORECAST.

&&

.AVIATION...
00Z TAF CYCLE

VFR CONDITIONS WILL CONTINUE THROUGH THE EVENING HOURS. ISOLATED
SHOWERS WILL MOVE ACROSS THE FORECAST AREA THIS EVENING BUT THE
COVERAGE WILL BE TOO LIMITED TO MENTION IN TAFS. LOW CLOUDS WILL
MOVE INTO THE REGION OVERNIGHT PRODUCING LIFR CEILINGS. SOME FOG
WILL OCCUR OVERNIGHT AS WELL. VFR CONDITIONS WILL RETURN FRIDAY
MORNING WITH SCATTERED THUNDERSTORMS EXPECTED DURING THE
AFTERNOON HOURS. WINDS WILL BE MAINLY FROM THE SOUTH AT AROUND 5
KNOTS FOR MUCH OF THE FORECAST PERIOD.

ARS

&&

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

$$



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