Area Forecast Discussion
Issued by NWS Huntsville, AL

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000
FXUS64 KHUN 291609 AAB
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1109 AM CDT FRI APR 29 2016

.UPDATE...TO TWEAK HIGH TEMPERATURES AND LOWER DEWPOINTS...AND RAISE
POP VERY LATE THIS AFTERNOON IN NW AL.

&&

.DISCUSSION...
A LARGE MCS FEATURE HAS DEVELOPED OVER ARKANSAS THIS MORNING WITH
SOME STRONG TO SEVERE THUNDERSTORMS DEVELOPING WITH THIS FEATURE.
MUCH OF NORTHERN ALABAMA AND WESTERN TN IS EXPERIENCING SOME VERY
THIN AND HIGH CLOUDS BEING ADVECTED INTO THE AREA COURTESY OF THIS
MCS.

THIS MCS IS DEVELOPING ALONG AND NORTH OF A WARM FRONT WHICH EXTENDS
FROM CENTRAL MISSISSIPPI WESTWARD INTO SOUTHERN ARKANSAS. STRONG
OVERUNNING COURTESY OF A DEVELOPING LOW LEVEL JET IS HELPING TO
PRODUCE A WIDESPREAD HEAVY RAINFALL AND EMBEDDED THUNDERSTORMS OVER
NORTHERN ARKANSAS INTO NORTHWESTERN TN.

BASED ON MODEL GUIDANCE AND CURRENT MOVEMENT OF PRECIPITATION
ASSOCIATED WITH THIS SYSTEM...PRECIPITATION SHOULD PUSH INTO NW AL
BETWEEN 3 AND 5 PM. CAN NOT RULE OUT AN ISOLATED SHOWER OR STORM NEAR
THE AL/MS BORDER BETWEEN 1 AND 3 PM. HOWEVER...DRY AIR ADVECTING IN
FROM THE EAST SHOULD KEEP POPS AT BAY UNTIL BETWEEN 3 AND 4 PM...WHEN
THE WARM FRONT EXTENDING EAST FROM CENTRAL MISSISSIPPI INTO SOUTHWEST
ALABAMA PUSHES FURTHER NORTH INTO NW AL. LUCKILY VERY LITTLE HELICITY
WILL BE IN PLACE THROUGH MUCH OF THE AFTERNOON. HOWEVER...DECENT
VALUES OF CAPE AT LEAST AROUND 1500 J/KG(AND UP TO 2200 J/KG IN SOME
MODELS) ARE BEING PROGGED BY MODEL GUIDANCE. THIS SEEMS
REASONABLE...GIVEN THIN NATURE OF HIGH CLOUD COVER EXPECTED. SOME
SMALL HAIL LOOKS REASONABLE GIVEN PROGGED CAPE...DESPITE FREEZING
LEVEL AROUND 13000 FEET. BELIEVE MOST THUNDERSTORMS EVEN LATE THIS
AFTERNOON WILL BE STRONG IN NATURE...BUT CANNOT RULE OUT AN ISOLATED
SEVERE THUNDERSTORM PRODUCING LARGE HAIL OR DAMAGING WINDS.

STRONG FORCING IS PROGGED TO PUSH IN LATE THIS AFTERNOON AS THE
WEAKENING LOW LEVEL JET APPROACHES AND SURFACE LOW PUSHES INTO NW
ALABAMA. DUE TO INSTABILITY FORECAST BY MODELS...RAISED POP TO 80
PERCENT IN NW AL AND WEST OF I-65 TO HIGH CHANCE. KEPT A SHARP
GRADIENT IN POPS EAST OF I-65..DROPPING IT TO 10 PERCENT OR LESS IN
THOSE AREAS.

KTW

&&

.AVIATION...
/ISSUED 636 AM CDT FRI APR 29 2016/
FOR 12Z TAFS...
VFR WEATHER IS FORECAST ACROSS THE AREA INTO THE MID AFTERNOON. THAT
BEING SAID...ISOLATED CONVECTION INVOF KMSL COULD PRODUCE A BRIEF
VIS/CIG REDUCTION AT THE TERMINAL LATER THIS AFTERNOON AND IN THE
EVENING...AS SHOWER ACTIVITY AFFECTS NW ALABAMA. DRY WEATHER SHOULD
OTHERWISE CONTINUE INTO THE LATE NIGHT ELSEWHERE. LIGHT WINDS THIS
MORNING SHOULD BECOME SE AROUND 5KT BY AROUND 16Z...THEN S-SW 5-15KT
THIS AFTERNOON. WINDS SHOULD BECOME LIGHT FROM THE SE AFTER SUNSET.
BRIEF AND ERRATIC GUSTY WINDS ARE POSSIBLE INVOF SHOWERS THAT FORM.

RSB

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.


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