Area Forecast Discussion
Issued by NWS Huntsville, AL

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS64 KHUN 291758 AAC
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1258 PM CDT FRI APR 29 2016

.UPDATE...
FOR 18Z TAFS

&&

.DISCUSSION...
/ISSUED 1109 AM CDT FRI APR 29 2016/
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
OVERRUNNING 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...
FOR 18Z TAFS...CURRENT VFR VIS/CIG AT KHSV/KMSL TAF SITES WILL GIVE
WAY TO DETERIORATING CONDITIONS AS A COMPLEX OF SHRA/TSRA MOVES INTO
NRN AL. LATEST TIMING PLACES THE LINE OF SHRA/TSRA MOVING INVOF KMSL
BY 2130-2200Z. TSRA COVERAGE IS GENERALLY CONTINUOUS ALONG THE LINE
AND THUS FEEL CONFIDENT ABOUT TSRA CHANCES AT KMSL. IMPACTS THERE MAY
BE GREATER THAN AT KHSV AS THE ACTIVITY IS EXPECTED TO DECREASE IN
INTENSITY AS IT MOVES ACROSS NRN AL. TEMPO IFR CONDITIONS ARE FCST
FOR KMSL DUE TO THE COVERAGE/INTENSITY OF EXPECTED ACTIVITY...BUT
LOWER CIG/VIS MAY OCCUR BRIEFLY IF A HEAVIER CELL PASSES ACROSS THE
TAF SITE. RAPIDLY IMPROVEMENT IS ANTICIPATED ESPECIALLY AFTER 00-02Z
WITH VFR LARGELY PREVAILING THROUGH 30/1800Z.

KDW

&&

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

$$

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



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.