Severe Thunderstorm Warning 247, NWS Morristown, TN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
340 PM EDT THU JUL 10 2003

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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AFTERNOON FORECAST DISCUSSION
340 PM EDT THU JUL 10 2003

TONIGHT AND TOMORROW...SHORTWAVE TROUGH CURRENTLY OVER THE
MISSISSIPPI RIVER VALLEY IS INITIATING AREAS OF ORGANIZED CONVECTION
OVER THAT REGION AND INTO THE OHIO RIVER VALLEY AT THIS TIME. THIS
FEATURE IS PROJECTED TO CONTINUE AN EASTWARD PROGRESSION AND
APPROACH THE FORECAST AREA TONIGHT. AS A RESULT...SCATTERED
CONVECTION SHOULD CONTINUE OVERNIGHT AND THEREFORE HAVE CONTINUED
WITH LIKELY POPS IN THE FIRST PERIOD. SHORTWAVE TROUGH AXIS AND
SURFACE COLD FRONT MOVE THROUGH THE AREA EARLY TOMORROW WITH
SIGNIFICANTLY DRIER AIR TO FOLLOW. CHANCE POPS STILL LOOKS
APPROPRIATE FOR EARLY IN THE SECOND PERIOD WITH POPS DECREASING
THROUGH THE REMAINDER OF THE PERIOD. GUIDANCE TEMPS ARE GENERALLY
CLOSE AND APPEAR REASONABLE.

FRIDAY NIGHT THROUGH NEXT THURSDAY...LOOKS LIKE DRIER AIR WILL GIVE
FORECAST AREA A CLEAR AND COOLER NIGHT AFTER COOL FRONT PASSES.
ANOTHER SHORTWAVE LOOKS TO AFFECT REGION SATURDAY NIGHT AND SUNDAY
SO HAVE ADDED CHANCE SATURDAY NIGHT. THIS WILL BE CLOSE TO THE FRONT
JUST TO OUR SOUTH. AFTER FRONT PASSES THROUGH IT WILL BECOME
STATIONARY AND THEN DISSIPATE BY MONDAY. AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS SHOULD BE POSSIBLE FROM SUNDAY THROUGH THE
EXTENDED AS WARM...MOIST AIR MOVES BACK NORTH.

FCSTID =    9
CHA   71  87  65  89 /  60  30  10  10
TYS   70  85  63  85 /  60  30  10  10
TRI   67  83  61  84 /  70  40  10  10
OQT   70  85  63  85 /  60  30  10  10

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

TD

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EARLY AFTERNOON FORECAST DISCUSSION (UPDATE)
105 PM EDT THU JUL 10 2003

UPDATING ZONES FOR ADDITIONAL SEVERE THUNDERSTORM WATCH WHICH
INCLUDES ALL COUNTIES IN SOUTHEAST TENNESSEE AND WILL BE IN EFFECT
THROUGH THE AFTERNOON HOURS.

TD

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LATE MORNING FORECAST DISCUSSION (UPDATE)
1130 AM EDT THU JUL 10 2003

UPDATING ZONES FOR SEVERE THUNDERSTORM WATCH WHICH WILL BE IN EFFECT
THROUGH THE AFTERNOON HOURS.

TD

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LATE MORNING FORECAST DISCUSSION (UPDATE)
1000 AM EDT THU JUL 10 2003

NO CHANGES. MODELS DEPICT VERY MOIST ATMOSPHERE WITH RELATIVELY HIGH
PW VALUES PERSISTING. RADAR SHOWS CONVECTION ALREADY DEVELOPING ON
THE PLATEAU. TEMPS APPEAR REASONABLE. THEREFORE NO UPDATE WARRANTED
AT THIS TIME.

LCM
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EARLY MORNING FORECAST DISCUSSION
344 AM PM EDT THU JUL 10 2003

MODELS AGREE WITH SHOWING A SHORT-WAVE TROUGH MOVING INTO THE
TENNESSEE VALLEY TODAY.  PLENTY OF OLD OUTFLOW BOUNDARIES WILL BE
ACROSS THE REGION TODAY WHICH WILL HELP CONVECTION FIRE AGAIN
TODAY...ESPECIALLY WITH AFTERNOON HEATING AND DESTABILIZATION.
CAPES BETWEEN 2000-2500 J/KG ANTICIPATED THIS AFTERNOON WITH
AN INCREASING 850 MB JET NEAR 35 KNOTS. I EXPECT MAIN BAND OF
THUNDERSTORMS TO DEVELOP OVER THE WEST/MIDDLE TENNESSEE THEN
PRESS EAST INTO THE FORECAST AREA.

SOME OF THESE STORMS COULD PRODUCE DAMAGING STRAIGHT LINE WINDS...
MARGINALLY SEVERE HAIL AND HEAVY RAINS. WILL INCLUDE IN MORNING
HWO.

FRONT WILL MOVE ACROSS THE FORECAST AREA FRIDAY. WILL CONTINUE WITH
MORNING CONVECTION FOR NORTH AND CENTRAL AND THROUGH EARLY AFTERNOON
FOR THE SOUTHERN COUNTIES.  MODELS SOUNDING SHOW AIRMASS DRYING
OUT SIGNIFICANTLY FRIDAY AFTERNOON AND NIGHT WITH SKY BECOMING
PARTLY CLOUDY/MOSTLY CLEAR. FOR SATURDAY...A DRY DAY IS
ANTICIPATED...BUT A SECOND COOL FRONT/BOUNDARY PROGGED TO MOVE
SOUTH INTO THE OHIO VALLEY.

AS THE BOUNDARY MOVES SOUTH INTO THE FORECAST AREA SUNDAY...A
CHANCE OF SHOWERS AND THUNDERSTORMS WILL RETURN. WILL MAINTAIN A
CHANCE OF STORMS FOR MONDAY THROUGH WEDNESDAY GIVEN NORTHWEST FLOW
ALOFT.

FCSTID =   15
CHA   87  70  86  65 /  80  70  40  10
TYS   86  69  84  64 /  80  70  30  10
TRI   83  66  82  60 /  80  70  30  10
OQT   86  69  84  64 /  80  70  30  10

DH
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LATE EVENING FORECAST DISCUSSION (UPDATE)
1135 PM EDT WED JUL 9 2003

SHOWERS AND STORMS MOSTLY GONE.  UPDATED TO REMOVE OUTDATED WORDING
AND LEAVE A CHANCE FOR REDEVELOPMENT.

SP

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EVENING FORECAST DISCUSSION (UPDATE)
845 PM EDT WED JUL 9 2003

NEW AREA OF TRW COMING OFF OF PLATEAU ALONG WITH SEPARATE
SIGNIFICANT AREA OVER THE CENTRAL VALLEY.  HAVE UPDATED TO ACCOUNT
FOR THESE AREAS AND THEIR EXPECTED MOVEMENT.  LOOKS LIKE NORTHERN
HALF OF CWA WILL GET PLENTY OF STORMS THROUGH MIDNIGHT.  EXPECT SOME
WEAKENING...BUT ENOUGH TO REMAIN TO WARRANT UPDATE.

SP

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NCZ060-061-TNZ012>018-035>047-067>074-081>087-098>102-VAZ001-002-005-
006-008-111000-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MORRISTOWN TN
545 AM EDT THU JUL 10 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST
VIRGINIA...EAST TENNESSEE AND SOUTHWEST NORTH CAROLINA.

.DAY ONE (TODAY)...

A SLIGHT RISK OF SEVERE THUNDERSTORMS EXIST THIS AFTERNOON AND
EVENING ACROSS EAST TENNESSEE...SOUTHWEST VIRGINIA AND EXTREME
SOUTHWEST NORTH CAROLINA.  VERY WARM...MOIST AND UNSTABLE AIRMASS
REMAINS ACROSS THE TENNESSEE VALLEY AND SOUTHERN APPALACHIANS
TODAY.  AN UPPER LEVEL TROUGH OF LOW PRESSURE WILL MOVE EAST INTO
THE REGION LATE THIS AFTERNOON AND EVENING ALLOWING THUNDERSTORMS TO
DEVELOP.

A SQUALL LINE OF THUNDERSTORMS IS EXPECTED TO DEVELOP OVER WEST
AND MIDDLE TENNESSEE THIS AFTERNOON THEN MOVE EAST ACROSS EAST
TENNESSEE AND SOUTHWEST VIRGINIA.  SOME OF THESE STORMS MAY BECOME
SEVERE WITH THE MAIN CONCERN BEING DAMAGING STRAIGHT LINE
WINDS...HAIL AND HEAVY RAINS.  THE HEAVY RAINS MAY PRODUCE PONDING
OF LOW LYING AREAS...STREET FLOODING AND RAPID STREAM RISE.

.DAYS TWO THROUGH SEVEN (FRIDAY THROUGH WEDNESDAY)...

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION MAY BE NEEDED BY LATE THIS AFTERNOON AND EVENING.

STAY TUNED OR VISIT OUR WEBSITE AT WWW.SRH.NOAA.GOV/MRX.

DH