Severe Thunderstorm Warning 206, NWS Morristown, TN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
930 PM EDT FRI AUG 2 2002

THE FOLLOWING ARE ALL THE FORECAST DISCUSSIONS FROM THE PAST 24
HOURS...WITH THE MOST RECENT ON TOP. THIS PROVIDES A HISTORY OF THE
DEVELOPMENT OF THE CURRENT FORECAST.
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EVENING FORECAST DISCUSSION
930 PM EDT FRI AUG 2 2002

A FEW CONVECTIVE CELLS REMAIN OVER THE FORECAST AREA AT THIS TIME.
EXPECT THESE TO CONTINUE TO DIMINISH IN COVERAGE AND INTENSITY AND
ANTICIPATE BEING ABLE TO REMOVE POPS IN FIRST PERIOD. WILL WAIT
UNTIL THE LAST MINUTE TO DECIDE FOR SURE HOWEVER. WILL DEFINITELY
ISSUE UPDATE TO REMOVE EVENING WORDING. REST OF FORECAST APPEARS ON
TRACK.

LCM

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AFTERNOON FORECAST DISCUSSION
330 PM EDT FRI AUG 2 2002

A WEAK WAVE WILL CONTINUE TO PULL SOUTHWEST ACROSS THE SOUTHERN
APPALACHIANS THIS EVENING. COLDER MID-LEVEL TEMPERAUTRES HAVE
COMBINED TO DESTABILIZE THE AIRMASS WITH LIFTED INDICES BETWEEN -5
AND -8.  STRONG THUNDERSTORMS ARE CURRENTLY MOVING SOUTHWEST ACROSS
THE MOUNTAINS.  DUE TO THE DRY MID-LEVEL INTRUSION AND INVERTED-V
SIGNATURE OF THE SOUNDING...LOCALIZED DAMAGING DOWNBURST WINDS ARE
POSSIBLE.  ALSO...WBZ ARE SLIGHTLY LOWER THAN YESTERDAYS AND LOW
ENOUGH FOR MARGINAL SEVERE HAIL THIS EVENING.

WILL CONTINUE WITH SCATTERED THUNDERSTORMS MOUNTAINS AND SLIGHT POP
FOR VALLEY THIS EVENING.

FOR SATURDAY...WEAK FRONT WILL MOVE INTO THE CENTRAL APPALACHIANS
WITH CONTINUED MODERATELY UNSTABLE AIRMASS. GIVEN EXPECTED SOUTHWEST
MOVEMENT OF STORMS...WILL INCLUDE CHANCE POPS FOR SOUTHWEST
VA/NORTHEAST TN FOR TOMORROW.  ELSEWHERE...GENERALLY DRY...EXCEPT
ISOLATED TRW IN THE MTNS.

FOR SUNDAY...AVN IS LONE MODEL OUT IN BEING AGGRESSIVE IN PULLING
GULF MOISTURE BACK NORTH INTO THE SOUTHERN APPALACHIANS.  THE ETA/NGM
ARE NOT NEARLY AS AGGRESSIVE.  WILL TREND FORECAST TOWARD THE ETA/NGM
SOLUTION AND ONLY CALL FOR SLIGHT POPS FOR MOUNTAIN AREAS SUNDAY
AFTERNOON AND EVENING.

OTHERWISE...HOT...HAZY AND HUMID CONDITIONS PREVAIL.

FCSTID =
CHA   71  95  70  94 /  20  10  10  10
TYS   70  94  70  93 /  20  10  10  10
TRI   65  91  64  91 /  20  30  30  10
OQT   70  93  70  92 /  20  10  10  10

.MRX...
NC...NONE.
TN...NONE.
VA...NONE.

DH

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MORNING FORECAST DISCUSSION
945 AM EDT FRI AUG 2 2002

LARGE AREA OF HIGH PRESURE ALOFT REMAINS CENTERED ACROSS THE PLAINS
STATES WITH FORECAST AREA ON THE EAST EDGE OF THE RIDGE.  NORTHEAST
FLOW ALOFT EXIST WITH THIS MORNINGS SOUNDING INDICATING TEMPERATURES
ALOFT ARE SLIGHTLY COLDER THAN YESTERDAYS.  AGAIN...AIRMASS
MODERATELY UNSTABLE WITH FORECAST CAPES OF 2500-3000 J/KG WITH LIFTED
INDICES DROPPING TO -5 TO -8 LATER TODAY.  HOWEVER...ONLY LIFTING
MECHANISM IS LOCAL TERRAIN FEATURES.

GIVEN COLDER TEMPERAURES ALOFT WILL CONTINUE FORECAST OF SCATTERED
AFTERNOON/EVENING THUNDERSTORMS DEVELOPING OVER THE MOUNTAINS.  MAY
NEED TO INCLUDE A SLIGHT CHANCE FOR THE VALLEY LATE THIS AFTERNOON
AND EVENING.  STRONG/SEVERE THUNDERSTORM WAS ABLE TO MAKE IT INTO
BRISTOL AREA LATE YESTERDAY BEFORE DISSIPATING.

MAIN THREAT FROM THESE STORMS WILL ONCE AGAIN BE LOCALIZED DAMAGING
DOWNBURST WINDS AS MID-LEVEL DRYING AND INVERTED-V SIGNATURE
REMAINS.  ALSO...WBZ ARE A LITTLE LOWER TODAY SO MARGINAL SEVERE
HAIL A POTENTIAL AS WELL.

DH

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EARLY MORNING FORECAST DISCUSSION
330 AM EDT FRI AUG 2 2002

UPPER RIDGE BUILDS EAST OVER THE OHIO AND TENNESSEE VALLEYS THROUGH
THE WEEKEND BUT NORTHEAST FLOW AROUND IT WILL KEEP ENOUGH MOISTURE
OVER THE EASTERN MOUNTAINS TODAY FOR SCATTERED LATE AFTERNOON AND
EVENING SHOWERS AND THUNDERSTORMS. PRECIPITABLE WATER VALUES ON
MESOETA PROGGED SOUNDING WAS 1.5 INCHES THIS AFTERNOON AND EVENING
WITH CAPES AT 1500 J/KG. THIS SHOULD BE ENOUGH WITH HEATING FOR
THUNDERSTORMS TO DEVELOP WHICH WILL MOVE SOUTHWEST AROUND UPPER
LEVEL HIGH JUST LIKE YESTERDAY. SOME STRONG STORMS ARE POSSIBLE TOO.
MOISTURE AND INSTABILITY DROPS OFF SATURDAY SO WILL LEAVE DRY FOR
NOW. TEMPERATURES SHOULD STAY ABOUT THE SAME WITH HIGHS IN THE LOWER
TO MID 90S IN THE VALLEYS AND LOWS MID 60S NORTH VALLEY TO LOWER 70S
SOUTH.

FCSTID = 9
CHA   96  71  95  71 /   10  10  10  10
TYS   94  70  93  70 /   10  10  10  10
TRI   92  65  91  65 /   10  10  10  10
OQT   94  71  94  71 /   10  10  10  10

TD