Severe Thunderstorm Warning 150, NWS Morristown, TN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
1100 AM EDT SUN JUN 22 2008

.DISCUSSION...FORECAST ON TRACK. NO UPDATE PLANNED. SON

PREVIOUS DISCUSSION:
SHORT TERM...(TODAY AND TONIGHT)...CONVECTIVE PRECIPITATION (PCPN)
HAS FOR NOW MOVED OUT OF FORECAST AREA...WITH LINGERING TSRA OVER SE
KY MOVING ENE...AND TSRA OVER NRN GA MOVING ENE. PCPN YESTERDAY
AFTERNOON AND EVENING WAS VERY SPOTTY WITH LITTLE IF ANY ORGANIZED
PATTERN. NORTHWEST FLOW ALOFT AGAIN TODAY WITH FRONTAL BOUNDARY
STILL TO OUR NW...SO WOULD EXPECT A RANDOM NATURE TO PCPN AGAIN THIS
AFTERNOON AND EVENING. POSSIBLY AN OUTLFOW BOUNDARY AROUND THIS
MORNING...BUT NOT A GIVEN...THUS OPTED TO KEEP POPS IN THE 20 TO 30
PERCENT RANGE WITH HIGHER CHANCES ACROSS SMOKIES AND NRN MTNS. TOO
MUCH INSTABILITY NOT TO INCLUDE SRN VALLEY OF EAST TN WITH AT LEAST
SLIGHT CHANCE POPS.

FORECAST SOUNDINGS HAVE DRY LOW LEVELS WITH AN INVERTED V LOOK...SO
SEE POTENTIAL FOR A STRONG DOWNBURST WITH PULSE TYPE STORMS DURING
PEAK HEATING INTO EARLY EVENING. WILL MENTION GUSTY WINDS AS MAIN
THREAT IN THE HAZARDOUS WEATHER OUTLOOK. PERHAPS A BETTER THREAT OF
SEVERE STORMS MONDAY AS TROUGH ALOFT DEEPENS AND PROVIDES MORE UPPER
LEVEL SUPPORT AND A CHANCE OF HAIL DUE TO MID LEVEL COOLING.

OTHERWISE...FOR SHORT TERM ADDED PATCHY FOG THIS MORNING WHERE MAIN
AREA OF PCPN OCCURRED YESTERDAY. CHOSE WARMER MAX TEMPS WHERE MOS
DIFFERED TODAY...AND A BLEND OF NAM-WRF AND GFS FOR TONIGHT.

LONG TERM...(MONDAY THROUGH SATURDAY)...UPPER LOW OVER GREAT LAKES
EARLY MONDAY BRINGS SHORTWAVE TROUGH THROUGH TENNESSEE VALLEY WITH
SECONDARY SURFACE LOW AND WEAK COLD FRONT ACROSS SOUTHERN
APPALACHIANS WITH CHANCE OF SHOWERS AND THUNDERSTORMS. COLD
TEMPERATURES ALOFT ...STEEP LAPSE RATES AND MODERATE INSTABILITY
WILL HELP THUNDERSTORMS DEVELOP WITH THE POSSIBILITY OF LARGE HAIL.
THE PRECIPITATION WILL MOVE OUT DURING THE EVENING AND UPPER TROUGH
WILL SHIFT EAST AWAY FROM THE FORECAST AREA TUESDAY. SURFACE HIGH
PRESSURE AND UPPER LEVEL RIDGING WITH DRIER AIRMASS WILL TAKE
CONTROL TUESDAY WITH NO PRECIPITATION AND WARMER TEMPERATURES. FROM
WEDNESDAY THROUGH SATURDAY SURFACE HIGH SHIFTS EAST A LITTLE WITH
FLAT RIDGE OVER THE SOUTHEAST. WEAK SHORT WAVES MOVING THROUGH A
WESTERLY FLOW ALOFT WILL TRIGGER MAINLY LATE AFTERNOON AND EARLY
EVENING CONVECTION. LOWS MONDAY NIGHT WILL BE BELOW NORMAL WITH UPPER
TROUGH AND DRIER AIR MOVING IN BUT WILL WARM TO THE MID TO UPPER 60S
MOST LOWER ELEVATION SPOTS FROM MID WEEK THROUGH THE END OF THE
PERIOD AS LOW LEVEL MOISTURE INCREASE UNDER UPPER RIDGE. HIGH
TEMPERATURES WILL BE NEAR TO A DEGREE OR TWO ABOVE NORMAL.
&&

.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN  87  64  86  60  90 /  20  10  30  10  10
KNOXVILLE AIRPORT, TN    86  61  83  60  86 /  20  10  30  10  10
OAK RIDGE, TN            85  60  83  59  87 /  20  10  30  10  10
TRI CITIES AIRPORT, TN   84  57  81  55  84 /  20  20  30  20  10
&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&

TG/TD

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MORRISTOWN TN
500 AM EDT SUN JUN 22 2008

NCZ060-061-TNZ012>018-035>047-067>074-081>087-098>102-VAZ001-002-
005-006-008-230900-
CHEROKEE-CLAY-SCOTT TN-CAMPBELL-CLAIBORNE-HANCOCK-HAWKINS-
SULLIVAN-JOHNSON-MORGAN-ANDERSON-UNION-GRAINGER-HAMBLEN-
NORTHWEST COCKE-COCKE SMOKY MOUNTAINS-NORTHWEST GREENE-
SOUTHEAST GREENE-WASHINGTON TN-UNICOI-NORTHWEST CARTER-
SOUTHEAST CARTER-ROANE-LOUDON-KNOX-JEFFERSON-NW BLOUNT-
BLOUNT SMOKY MOUNTAINS-NORTH SEVIER-SEVIER SMOKY MOUNTAINS-
SEQUATCHIE-BLEDSOE-RHEA-MEIGS-MCMINN-NORTHWEST MONROE-
SOUTHEAST MONROE-MARION-HAMILTON-BRADLEY-WEST POLK-EAST POLK-LEE-
WISE-SCOTT-RUSSELL-WASHINGTON-
500 AM EDT SUN JUN 22 2008 /400 AM CDT SUN JUN 22 2008/

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

.DAY ONE...TODAY AND TONIGHT

ISOLATED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP TODAY
INTO THE EVENING HOURS. A FEW STORMS COULD BRIEFLY INTENSIFY TO
BECOME MARGINALLY SEVERE...WITH THE MAIN THREAT BEING DAMAGING
DOWNBURST WINDS UP TO 50 MPH...AS WELL AS PEA TO DIME SIZED HAIL.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

AN UPPER LEVEL TROUGH OF LOW PRESSURE WILL APPROACH THE REGION AND
DEEPEN ON MONDAY...CAUSING A BETTER CHANCE OF SEVERE STORMS MONDAY
AFTERNOON AND EVENING. TEMPERATURES WILL COOL ALOFT AND CREATE A
THREAT OF LARGE HAIL...WITH DAMAGING DOWNBURST WINDS ALSO POSSIBLE
WITH THE STRONGER STORMS.

OTHERWISE...NO HAZARDOUS WEATHER IS EXPECTED FROM TUESDAY THROUGH
SATURDAY AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED ON MONDAY AFTERNOON AND EVENING.

TG