Severe Thunderstorm Warning 224, NWS Morristown, TN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
307 PM EDT MON AUG 19 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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AFTERNOON FORECAST DISCUSSION
307 PM EDT MON AUG 19 2002

CONVECTION FIRING ACROSS CWA ALONG AN OUTFLOW BOUNDARY FROM DYING
MCS IN KY.  SECOND LINE BEGINNING TO ENTER NORTH CENTRAL TN.  THINK
MOST OF THE ACTIVITY WILL OCCUR BEFORE 00Z...BUT WILL GO WITH A 40
POP FOR THIS EVENING.  BEST COVERAGE SHOULD REMAIN IN THE NORTH.
WITH THE RAIN THIS AFTERNOON/EVENING...SHOULD SEE SOME FOG
DEVELOPING AFTER MIDNIGHT.  THINK WE WONT HAVE TO WORRY ABOUT
WIDESPREAD DENSE FOG.  SOME BIG MODEL DIFFERENCES FOR TUESDAY.
MESOETA AND NGM PUSH HIGH PRESSURE AND DRY AIR INTO CWA...WHILE AVN
SHOWING MORE MOISTURE AND PRECIP OVER AREA.  AM LEANING TOWARD THE
DRIER ETA/NGM...BUT WILL KEEP SLIGHT CHANCE POPS FOR THE HIGHER
ELEVATIONS FOR TUES AFTERNOON AND EVENING.  AVN FINALLY PUSHES DRIER
AIR IN BY WED IN AGREEMENT WITH THE ETA/NGM.  WILL GO WITH DRY AND
WARMER WEATHER FOR WEDNESDAY.

CHA   71  92  70  94 /  40  10  10  10
TYS   69  90  68  92 /  40  10  10  10
TRI   65  88  64  89 /  40  10  10  10
OQT   69  90  68  92 /  40  10  10  10

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

GH

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LATE MORNING FORECAST DISCUSSION (UPDATE)
1000 AM EDT MON AUG 19 2002

FOG HAS DISSIPATED...WILL UPDATE ZONES TO REMOVE IT.  MCS SHOULD
REMAIN TO OUR NORTH...BUT PROBABLY SEE THICKER HIGH CLOUDS IN OUR
NORTHERN ZONES.  WILL GO WITH A MOSTLY CLOUDY SKY IN THE NORTH.
ALSO EXPECTING A FEW OUTFLOWS TO MOVE INTO OUR AREA BY THIS
AFTERNOON.  WITH THE GOOD INSTABILITY...WILL BUMP UP POPS TO 40
PERCENT IN ALL AREAS.  WILL ALSO LOWER WINDS A BIT IN THE VALLEY
WITH A FAIRLY WEAK GRADIENT.  TEMPERATURES LOOK GOOD.

GH

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MORNING FORECAST DISCUSSION
330 AM EDT MON AUG 19 2002

WEAK SURFACE FRONT STILL LINGERING TO THE WEST OF THE FORECAST AREA
ACROSS MIDDLE TENNESSEE WILL SLOWLY DRIFT ACROSS THE AREA OVER THE
NEXT 36 HOURS.

SOME BIG DIFFERENCES IN THE ETA AND THE GFS/AVN MODELS ON TUESDAY.
ETA HAS THE AREA COMPLETELY DRIED OUT BY TUESDAY WHILE AVN HANGS ON
TO GOOD MOISTURE.  HAVE LEANED TOWARDS THE AVN AND PUT SLIGHT CHANCE
SHOWERS IN THE TERRAIN AREAS OF THE FORECAST AREA.

TEMPERATURES WILL BEGIN TO CLIMB TODAY THROUGH WEDNESDAY UNDER
SOMEWHAT CLEAR SKIES...EVEN WITH THE WETTER AVN MODEL.

CHA   90  69  92  69 /  30  30   0  10
TYS   88  70  90  67 /  30  30   0  10
TRI   87  66  87  63 /  30  30   0  10
OQT   88  70  90  67 /  30  30   0  10

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EVENING FORECAST DISCUSSION
855 PM EDT SUN AUG 18 2002

LINE OF SHOWERS AND THUNDERSTORMS THAT MOVED SOUTHEAST FROM KENTUCKY
AND MIDDLE TN EARLIER THIS AFTERNOON INTO SW VIRGINIA AND NORTHEAST
TN THIS EVENING SENT AN OUTFLOW BOUNDARY THROUGH THE MORRISTOWN AREA
THE PAST HOUR. WIDELY SCATTERED SHOWERS AND THUNDERSTORMS ARE
BEGINNING TO DECREASE ACROSS NORTHEAST TENNESSEE. STRONG
THUNDERSTORMS CONTINUE WEST AND NORTHWEST OF CHATTANOOGA. RUC SHOWS
SHORTWAVE MOVING ACROSS WEST AND MIDDLE TN WITH WEAKER VORTICITY
LOBE EXTENDING ACROSS NORTHEAST TN. THIS SHORTWAVE MOVES SOUTHEAST
INTO NORTH AL OVERNIGHT TONIGHT. CURRENT FORECAST HAS A CHANCE
THUNDER. PLANNING TO KEEP SLIGHT CHANCE NORTHERN AREAS AND 30
PERCENT SOUTHERN SECTIONS A FEW MORE HOURS. MAY HAVE TO UPDATE AGAIN
TO TAKE RAIN CHANCE OUT FOR THE REMAINDER OF THE NIGHT.

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

TD