Severe Thunderstorm Warning 162, NWS Morristown, TN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
243 PM EDT THU JUL 4 2002

RADAR SHOWS SCATTERED CONVECTION FIRING ACROSS EXTREME NORTHEAST
TENNESSEE/SOUTHWEST VIRGINIA THIS AFTERNOON. AIRMASS ACROSS THE
FAR NORTHEAST COUNTIES ARE VERY UNSTABLE WITH LIFTED INDICES
AT OR BELOW -10...PER MSAS.  SLIGHTLY DRIER DEWPOINTS AND
LOWER TEMPS (DUE TO MORNING CLOUDS) OVER THE CENTRAL AND SOUTHERN
VALLEY HAVE LIMITED INSTABILITY THERE SO FAR.  I EXPECT STORMS
TO CONTINUE TO BUILD AND MOVE SLOWLY WEST SOUTHWEST...SIMILAR
TO YDAS. DUE TO HIGH K-INDICES AND HIGH CAPES/LIS...MAIN
THREAT WILL BE TORRENTIAL RAINS...MARGINAL SEVERE HAIL AND
STRONG DOWNBURSTS WINDS.

WILL CALL FOR BEST COVERAGE THIS EVENING FOR NORTHEAST AND
ALONG AND FAR EASTERN TENNESSEE MOUNTAINS. AFTER LOSS OF DAYTIME
HEATING...ACTIVITY WILL GIVE WAY TO PARTLY CLOUDY SKY AND PATCHY
FOG.

MODELS ARE IN AGREEMENT WITH RETROGRADING UPPER RIDGE OVER THE
OHIO VALLEY WEST AS UPPER TROUGH ESTABLISHES ITSELF OVER THE
NORTHEAST/MID-ATLANTIC STATES. THIS TROUGH WILL ALLOW A FRONT
TO MOVE INTO THE NORTHERN FORECAST AREA LATE FRIDAY THEN MOVE
TO NEAR CHA BY SATURDAY MORNING. AIRMASS WILL REMAIN QUITE
UNSTABLE AHEAD OF FRONT WITH THETA-E RIDGE AXIS OVER THE AREA
TOMORROW AFTERNOON. WILL ONLY CALL FOR SCATTERED CONVECTION
SINCE CONVERGENCE ALONG AND AHEAD OF FRONT IS WEAK AND NO UPPER
SUPPORT NOTED. CONVECTION WILL MAINLY BE AFTERNOON/EVENING
VARIETY GIVEN LACK OF UPPER DYNAMICS.

FOR SATURDAY...MODELS SHOW THETA-E RIDGE AXIS REMAINING CLOSE
ENOUGH TO SOUTHERN THIRD AND FAR EASTERN TENNESSEE MOUNTAINS TO
WARRANT CONTINUED CHANCE OF AFTERNOON STORMS.  ELSEWHERE...
SLIGHTLY DRIER AIR WILL BE THE RULE WITH MOSTLY SUNNY/PARTLY CLOUDY
SKY.

LONG-RANGE...EXPECT A FRONT TO MOVE THROUGH THE AREA WED WITH
SLIGHTLY COOLER AND DRIER AIR FINALLY MAKING ITS WAY INTO THE GREAT
VALLEY.  WOULD NOT BE TERRIBLY SURPRISED TO SEE IT HOLD OFF TIL THU
THOUGH, BASED ON PAST MODEL PERFORMANCE IN TIMING.

FCSTID =
CHA   69  94  71  91 /  30  30  30  30
TYS   69  92  70  90 /  30  40  30  10
TRI   63  90  64  87 /  30  40  30   0
OQT   69  93  69  90 /  30  40  30  10

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

DH

NCZ060-061-TNZ012>018-035>047-067>074-081>087-098>102-VAZ001-002-005-
006-008-050400-

AREA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE MORRISTOWN TN
1139 AM EDT THU JUL 4 2002

...THERE IS A CHANCE OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING ACROSS EAST TENNESSEE...SOUTHWEST VIRGINIA...AND EXTREME
SOUTHWEST NORTH CAROLINA...

SCATTERED THUNDERSTORMS WILL DEVELOP ACROSS THE SOUTHERN APPALACHIAN
REGION THIS AFTERNOON AND EVENING.  THE MAIN THREATS FROM THESE
STORMS WILL BE STRAIGHT-LINE WINDS TO 70 MPH AND HAIL TO ONE INCH IN
DIAMETER.

A MOIST AND UNSTABLE AIRMASS WILL CONTINUE ACROSS THE AREA TODAY.
SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS EAST
TENNESSEE...SOUTHWEST VIRGINIA...AND SOUTHWEST NORTH CAROLINA DURING
THE AFTERNOON AND EVENING HOURS.  STORMS WILL LIKELY BEGIN AROUND 1
PM OVER THE HIGHER TERRAIN OF THE MOUNTAINS AND CUMBERLAND
PLATEAU... THEN MOVE OFF TOWARD THE WEST OR SOUTHWEST AT 5 TO 10
MPH.  SOME OF THESE THUNDERSTORMS WILL BECOME SEVERE.  ALONG WITH
THE MAIN THREATS OF STRAIGHT-LINE WINDS UP TO 70 MPH AND HAIL TO ONE
INCH IN DIAMETER...LOCALLY HEAVY RAINFALL AND FREQUENT LIGHTNING ARE
LIKELY.

SPOTTER ACTIVATION MAY BE REQUIRED ACROSS THE AREA THIS AFTERNOON.
EVERYONE SHOULD STAY TUNED TO NOAA WEATHER RADIO...OR YOUR FAVORITE
RADIO OR TELEVISION STATION...FOR THE LATEST WEATHER UPDATES AND
POSSIBLE WARNINGS FROM YOUR NATIONAL WEATHER SERVICE.

SP