Area Forecast Discussion
Issued by NWS Huntsville, AL

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000
FXUS64 KHUN 030819
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
319 AM CDT MON AUG 3 2015

.SYNOPSIS...

GENERALLY QUIET AND HOT AMBIENT WEATHER CONDITIONS WILL PREVAIL ON
MONDAY AND TUESDAY. THEN, A SHIFT IN THE PREVAILING "WINTER LIKE"
UPPER LEVEL PATTERN, WITH DUAL BROAD TROUGHS ON EITHER COAST, WILL
OCCUR BY MID-WEEK. THIS SHIFT WILL BRING A COUPLE OF MID-LEVEL
SHORTWAVE TROUGHS RESULTING IN SENSIBLE WEATHER IMPACTS ON WEDNESDAY
THROUGH FRIDAY.

SL.77

&&

.DISCUSSION...

A WEAK SFC RIDGE AND PREVAILING DRY AIR ALOFT WILL KEEP THE TN
VALLEY HOT AND DRY FOR THE NEXT COUPLE OF DAYS WITH ABOUT A 25-30
DEGREE SWING IN TEMPS FROM DAYTIME HIGHS TO OVERNIGHT LOWS THIS
MORNING. AS THE SFC RIDGE BEGINS TO MOVE EASTWARD TOWARDS THE
CAROLINAS, WEAK SOUTHERLY FLOW WILL ACT TO INCREASE SFC DEWPOINTS
BACK INTO THE UPPER 60S TONIGHT. AS A RESULT, BY TUESDAY, HUMID AND
HOT CONDITIONS SHOULD RETURN AFTER A RESPITE FROM THE HUMIDITY OVER
THE PAST SEVERAL DAYS.

THE MID-LEVEL FLOW PATTERN THEN BECOMES RATHER UNIQUE FOR THIS TIME
OF YEAR WITH A SHEARED TROUGH AMPLIFYING INTO A SHORTWAVE TROUGH.
THIS SHEARED TROUGH WILL BE ROTATING AROUND A BUILDING RIDGE OVER THE
DESERT SOUTHWEST TO THE S PLAINS. AS IT APPROACHES THE MO RIVER
VALLEY AND AMPLIFIES, SHOWERS AND THUNDERSTORMS SHOULD DEVELOP ON
TUESDAY NIGHT INTO WEDNESDAY OVER MO/KS TO WESTERN PORTIONS OF THE
OH/MS RIVER VALLEYS. IT IS CHALLENGING TO ASCERTAIN THE SENSIBLE
IMPACTS OVER THE TN VALLEY, BUT IT APPEARS THAT SCT THUNDERSTORMS MAY
DEVELOP OVER S TN, FROM UPSTREAM OUTFLOW BOUNDARIES ON WEDNESDAY, AND
SHIFT SOUTHEAST. AS A RESULT, HAVE ADDED A GRADIENT IN POPS FROM N TO
S FOR THIS POSSIBILITY.

THEN, WITH THE BROAD TROUGH OVER QUEBEC MOVING EAST ACROSS NOVA
SCOTIA AND NEW FOUNDLAND, WHILE THE RIDGE BUILDS OVER THE S PLAINS,
AN ALMOST CONTINUOUS SHORTWAVE TROUGH TRACK DEVELOPS OVER MO RIVER
VALLEY. THE NEXT SHORTWAVE TROUGH IS PROGGED TO ARRIVE ON THURSDAY
INTO FRIDAY WHICH SHOULD TAP INTO THE LLJ SUFFICIENTLY TO ADVECT
MID TO UPPER LEVEL GULF MOISTURE ACROSS THE SOUTHEAST. FURTHERMORE,
STEEP LOW TO MID-LEVEL LAPSE RATES WILL TRANSLATE TO INSTABILITY
RISING ON THURSDAY AFTERNOON AND EVENING. THOUGH WIND SHEAR APPEARS
TO BE ANEMIC, THE VORTICITY MAXIMA MAY ENHANCE WIND SHEAR WHICH MAY
BE THE REASON SOME MODEL OUTPUT APPEARS TO BE OVER DOING THE WIND
SHEAR. ADDITIONALLY, IT APPEARS A WARM FRONT MAY STALL JUST TO THE
NORTH OF THE AREA ON THURSDAY INTO FRIDAY WHICH COULD PROVIDE FOCUS
FOR MORE DEVELOPMENT THAT WOULD MOVE SOUTH TOWARDS TN VALLEY. WITH
THESE QUESTIONS STILL REMAINING, STRONG THUNDERSTORMS AT LEAST LOOK
POSSIBLE FOR THURSDAY AFTERNOON AND EVENING WITH VERY HEAVY RAINFALL
AND GUSTY WINDS UP TO 40 MPH POSSIBLE. THE CHANCES FOR THUNDERSTORMS
WILL CONTINUE THROUGH SATURDAY AS AT LEAST 2 MORE SHORTWAVE TROUGHS
MOVE WITHIN THE MO RIVER CORRIDOR TOWARDS THE TN VALLEY. AS A RESULT
OF THE `WETTER` NW FLOW PATTERN, DAYTIME HIGH TEMPERATURES WILL BE
COOLER--IN THE MID TO UPPER 80S FOR THURSDAY THROUGH FRIDAY. THE
RIDGE OVER S PLAINS THEN BUILDS EAST ON SATURDAY AND SUNDAY BRINGING
A RETURN TO DRIER CONDITIONS.

SL.77

&&

.AVIATION...
/ISSUED 1147 PM CDT SUN AUG 2 2015/
FOR 06Z TAFS...HIGH PRESSURE ACROSS THE REGION WILL PROVIDE FOR VFR
CONDITIONS THRU THE FCST PERIOD.

07

&&

.PRELIMINARY POINT TEMPS/POPS...
HUNTSVILLE    96  70  97  72 /   0   0  10  10
SHOALS        95  70  97  72 /   0   0   0  10
VINEMONT      94  69  94  71 /   0   0  10  10
FAYETTEVILLE  94  68  93  70 /   0   0  10  10
ALBERTVILLE   93  68  94  71 /   0   0  10  10
FORT PAYNE    94  65  94  69 /   0   0  10  10

&&

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

$$

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


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