Severe Thunderstorm Warning 237, NWS Morristown, TN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
335 PM EDT MON AUG 26 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
335 PM EDT MON AUG 26 2002

MODELS AGREE ON UPPER LOW TRACK.  WILL KEEP A CHANCE OF SHOWERS AND
THUNDERSTORMS OVER THE AREA THROUGH SATURDAY.  WILL SEE NEAR NORMAL
TEMPERATURES THROUGH THIS PERIOD.  IT IS DIFFICULT TO PIN DOWN THE
TIMING FOR THE MAIN AREAS OF PRECIPITATION THAT WE EXPECT OVER THE
NEXT 48 HOURS.  MUST ADMIT THAT THE EXACT LOCATIONS OF THE
CONVECTIVE DEVELOPMENT OVER THAT LAST 24 HOURS WERE NOT NAILED IN
ADVANCE.  THE ENTIRE AREA IS UNSTABLE...AND THE TRIGGERING
MECHANISMS RANGE FROM OROGRAPHY TO OLD OUTFLOW BOUNDARIES TO SUNNY
SPOTS THAT OCCUR IN AREAS THAT DIDNT HAPPEN TO GET OVERNIGHT
CONVECTION.  IN THIS SCENARIO...PRECISION IS TRICKY.  HAVE GENERALLY
TRENDED WITH THE HIGHER POPS TO THE NORTH BASED ON UPSLOPE AND LOW
LEVEL CONVERGENCE SIGNATURES IN MOST MODEL DATA...BUT AM SURE WILL
SEE MORE COVERAGE IN SOME OTHER AREA SOMETIME DURING THE FORECAST
PERIOD.

CHA   67  86  67  85 /  20  40  30  40
TYS   66  84  66  82 /  30  50  40  50
TRI   65  80  65  79 /  40  60  50  50
OQT   65  84  65  82 /  30  50  40  50

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

PARKER

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MORNING FORECAST DISCUSSION
957 AM EDT MON AUG 26 2002

FORECAST CALLS FOR MOSTLY CLOUDY SKIES...WHICH SHOULD MATERIALIZE IN
THE NEXT COUPLE OF HOURS AS THE SUN WARMS THE WET GROUND AND CU POPS
UP EVERYWHERE.  STILL FEEL POPS ARE WARRANTED AND CHANCES BEST IN
THE NORTH...SO NO UPDATE PLANNED AT THIS TIME.  WILL MONITOR TEMPS
AND ISSUE LATER UPDATE IF MAXES WILL NOT BE REACHED.

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

29

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EARLY MORNING FORECAST DISCUSSION
310 AM EDT MON AUG 26 2002

MODELS CONTINUE TO PROJECT AN UPPER LOW TO DEVELOP AND REMAIN
ESSENTIALLY STATIONARY OVER THE KY/TN REGION THROUGH MID WEEK. THIS
FEATURE WILL INDUCE UNSETTLED WEATHER FOR THE SOUTHERN APPALACHIANS.
AXIS OF BEST MOISTURE WILL REMAIN EAST OF THE FORECAST AREA AND AS
SUCH THE BEST COVERAGE OF PRECIP IS EXPECTED TO BE IN OUR
NORTHEASTERN ZONES...WITH A GRADUAL GRADATION TO LOWER POPS IN THE
SOUTHWESTERN ZONES. THE UPPER LOW IS PROJECTED TO DRIFT SOUTH THROUGH
THE BALANCE OF THE WEEK BUT OUR FORECAST AREA WILL BE LEFT IN A MOIST
REGIME AS ITS LEGACY.

MORE CLIMATOLOGICALLY SEASONAL TEMPS ARE ALSO IN STORE AS A
RESULT OF MORE CLOUD COVER AND LOWERING HEIGHTS ASSOCIATED WITH
UPPER LOW. GUIDANCE TEMPS GENERALLY AGREE AND APPEAR REASONABLE.
FOLLOWED THOSE NUMBERS CLOSELY FOR THE MOST PART.

PRELIMINARY TEMPS AND POPS FOLLOW FOR COORDINATION:

CHA   89  69  88  68 /  40  30  40  30
TYS   85  66  84  65 /  50  40  50  40
TRI   79  63  79  62 /  70  50  60  50
OQT   85  65  84  65 /  40  30  50  40

LCM

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EVENING FORECAST DISCUSSION (UPDATE)
845 PM EDT SUN AUG 25 2002

ONGOING SHOWERS WILL CONTINUE PAST MIDNIGHT AND WITH LIS FORECAST
TO STAY NEGATIVE ALL NIGHT AND MULTIPLE OUTFLOW BOUNDARIES TO WORK
FROM REDEVELOPMENT IS NOT OUT OF THE QUESTION.  WITH THIS IN
MIND...NO CHANGES PLANNED TO THE CURRENT FORECAST.