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 031833
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
133 PM CDT THU SEP 3 2015

.DISCUSSION...
ISOLD CONVECTIVE CELLS HAVE DEVELOPED FROM MIDDLE TN INTO NERN AL
EARLY THIS AFTERNOON. THIS DEVELOPMENT HAS BEEN ALONG A WEAK
CONVERGENCE ZONE WITHIN THE NWRN QUADRANT OF COMPACT UPR CIRCULATION
THAT IS EXITING NERN AL PER WATER VAPOR IMAGERY. THE HRRR SUGGESTS
THAT THIS "BAND" OF CELLS WILL MOVE S-SW THIS AFTERNOON AND
DETERIORATE QUICKLY BY 23-00Z. FOR NOW, WILL LEAVE A DRY FORECAST FOR
TONIGHT. ANOTHER MUGGY NIGHT IS AHEAD ALONG WITH PATCHY FOG LIKELY
GIVEN DEW POINTS REMAINING IN THE U60S-L70S, LIGHT FLOW AND A MOSTLY
CLEAR SKY. FRIDAY SHOULD BE ANOTHER VERY WARM AND MUGGY DAY. THE TAIL
END OF A WEAK WAVE DROPPING SE IN THE UPPER FLOW ALONG WITH SOME
UPLIFT ALONG THE CUMBERLAND PLATEAU MAY INSTIGATE A FEW CELLS AGAIN
FRIDAY AFTERNOON. I PRESUME THAT THESE WILL BE SIMILAR IN AREAL
COVERAGE AND MOSTLY WEAK-MODERATE INTENSITY LIKE WE ARE OBSERVING
TODAY. THIS WOULD BE MAINLY IN SRN TN AND NERN AL WHERE WE HAVE
POSTED ISOLD T IN THE FORECAST. FORECAST WILL SIDE WITH THE NAM/MEN
DEW POINT VALUES OVER THE RAW GFS/GFSMOS WHICH CONTINUE A TREND OF
BEING TOO LOW, ESPECIALLY DURING THE DAYLIGHT HOURS.

OVER THE WEEKEND, A SFC/8H ANTICYCLONE WILL BE LOCATED OVER THE
MIDDLE AND LOWER OHIO VALLEY. THERE WILL ALSO BE A CONTINUED PRESENCE
OF AN UPPER LEVEL LOW OVER THE CAROLINA COASTLINE WITH A FEW SPOKES
OF VORTICITY CIRCULATING ON ITS NORTHERN QUADRANT. THIS SYSTEM ALSO
PRODUCES A "BACK DOOR" COLD FRONT WHICH ARRIVES SATURDAY EVENING IN
OUR EASTERN COUNTIES. AT THIS POINT, MOST OF THE AREA SHOULD REMAIN
DRY ON SATURDAY, WITH LOW CHCS OF A FEW SHRA/TSTMS IN OUR EASTERN
COUNTIES AS THE FRONT ARRIVES. THE GFS APPEARS TO OVER-FORECAST
AREAL COVERAGE OF PRECIP SATURDAY NIGHT INTO SUNDAY, SO HAVE OPTED
CLOSER TO THE NAM.

THE LOW TO MID LEVEL HIGH PRESSURE CELL OVER THE OHIO VALLEY BUILDS
FURTHER SE EARLY NEXT WEEK. THE 5H UPR TROF AXIS PLAGUING THE FAR
SERN U.S. BEGINS TO SHIFT A BIT FURTHER NW BY MID WEEK BEFORE A FALL-
LIKE COLD FRONT TRACKS TO THE I-40 CORRIDOR THURSDAY. IT WOULD APPEAR
THAT THIS FRONT WILL NOT PROCEED THRU THE TN VALLEY WHICH WILL
CERTAINLY PLAY A ROLE IN THE FORECAST BEYOND D7.

&&

.AVIATION...
/ISSUED 1232 PM CDT THU SEP 3 2015/
FOR 18Z TAFS...LOW-LVL CU FIELD IS GRADUALLY DEVELOPING IN THE MOIST
UNSTABLE AIRMASS IN THE REGION. UAH GOES-R CI INDICATES CONTINUED
DEVELOPMENT IS LIKELY WITH SOME CELLS IN THE AREA OVER THE NEXT HOUR
OR SO. ALTHOUGH INSTABILITY IS MODERATE, WEAK SHEAR WILL LIMIT
SHRA/TSRA DEVELOPMENT AND LONGEVITY. COVERAGE OF ACTIVITY IS STILL
LIKELY TO BE ISOLD. THUS...WILL NOT PUT IMPACTS FROM CONVECTION IN
TAFS AT THIS TIME...BUT WILL MONITOR AND MAKE ANY NECESSARY
AMENDMENTS. FOG DEVELOPMENT IS MORE LIKELY AT TAF SITES TONIGHT WITH
BETTER RADIATIONAL COOLING CONDITIONS EXPECTED. MVFR FCST FOR KHSV
IFR FOR KMSL CURRENTLY...BUT GIVEN TENDENCY FOR FOG FORMATION AT KMSL
VIS REDUCTIONS ARE POSSIBLE IN LATER TAF UPDATES.

KDW

&&

.PRELIMINARY POINT TEMPS/POPS...
HUNTSVILLE    72  93  73  93 /  10  10  10  10
SHOALS        70  92  71  94 /  10  10  10  10
VINEMONT      70  89  71  89 /  10  10  10  10
FAYETTEVILLE  68  89  69  92 /  10  10  10  20
ALBERTVILLE   69  89  70  89 /  10  10  10  30
FORT PAYNE    67  90  68  90 /  10  10  10  30

&&

.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.