FXUS64 KMRX 022018
AFDMRX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
318 PM EST WED DEC 2 2009
.SHORT TERM...(TONIGHT THROUGH FRIDAY)...VERY DYNAMIC SYSTEM MOVING
ACROSS THE LOWER MISSISSIPPI AND TENNESSEE VALLEYS. VERY TIGHT
PRESSURE GRADIENT AROUND THE LOW PRESSURE SYSTEM IS PRODUCING HIGH
WINDS OVER THE HIGHER TERRAIN AND EASTERN TENNESSEE FOOTHILLS.
NUMEROUS REPORTS OF TREES DOWN ACROSS THESE AREAS WITH CAMP CREEK
OBSERVATION SITE IN EASTERN GREENE COUNTY REPORTED PEAK GUSTS UP TO
80 MPH. MOUNTAIN WAVE HIGH WINDS ARE THE CULPRIT.
AS COLD FRONT OVER MIDDLE TENESSEE AND ALABAMA MOVING ACROSS THE
AREA LATE THIS AFTERNOON-EVENING...WINDS WILL BECOME MORE SOUTH TO
SOUTHWEST. THE BOUNDARY LAYER JET STILL REMAINS QUITE STRONG WITH
850MB WINDS OF 50KTS. WILL EXTEND HIGH WIND WARNING UNTIL 06Z.
ALSO...AS FRONT MOVES THROUGH LOW LEVEL INVERSION WILL DISAPPEAR ALLOWING
BOUNDARY LAYER TO MIX. THE STRONGER WINDS ALOFT WILL HAVE A BETTER
CHANCE IN MIXING TO THE SURFACE. WILL INCLUDE THE REST OF THE AREA...
INCLUDING THE VALLEY...IN THE WIND ADVISORY THROUGH 06Z.
A UPPER JET IS MOVING ACROSS THE FORECAST AREA WITH A DRY SLOT VERY
EVIDENT. THIS DRY SLOT HAS ALLOWED BREAKS IN THE CLOUD COVER WITH
NAM SHOWING CAPES INCREASING TO 200-300 J/KG. WOULD NOT BE SUPRISED
TO HEAR A CLAP OF THUNDER AS A BROKEN LINE OF CONVECTION MOVES
NORTHEAST FROM NORTHEAST ALABAMA ACROSS MUCH OF THE FORECAST AREA
THIS EVENING. THIS LINE OF CONVECTION IS ALSO PRODUCING VERY WINDY
CONDITIONS WITH SOUTHWEST WINDS UP TO 50 MPH.
A LARGE AREA OF COLD AIR STRATO-CU MOVES INTO THE FORECAST AREA
OVERNIGHT AND REMAINS OVER THE REGION UNTIL THURSDAY NIGHT. MAY SEE
PARTLY CLOUDY SKIES FOR FRIDAY AHEAD OF NEXT SYSTEM.
TRENDED TOWARD THE GFS TEMPERATURES THROUGH THE SHORT-TERM.
.LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...DID NOT MAKE ANY MAJOR
CHANGES TO PREVIOUS FORECAST WHICH FEATURES A RATHER HEALTHY VORT
MAX DROPPING THROUGH THE BASE OF PERSISTENT NORTH CENTRAL U.S. UPPER
TROF AND SWINGING ACROSS THE FORECAST AREA LATER FRIDAY NIGHT
THROUGH SATURDAY. SURFACE AIRMASS DOESN'T GET A CHANCE TO ENJOY ANY
SIGNIFICANT WARM UP WITH LOW LEVEL COLD AIR ADVECTION CONTINUING
WITH SURFACE RIDGE IN PLACE. SOUNDINGS APPEAR TO BE COLD ENOUGH AND
WITH CRYSTALIZATION TAKING PLACE WITH HIGH LEVEL MOISTURE RIDING IN
OVER THE TOP IN CHILLY -15 TO -25 C AIR. APPEARS THAT SEEDING OF THE
LOWER LEVEL AIRMASS SHOULD HELP TO CREATE SNOW SHOWERS FRIDAY NIGHT
THROUGH SATURDAY WITH GREATEST IMPACT IN THE HIGHER TERRAIN. WENT
CONSERVATIVE FOR NOW DUE TO EVENT BEING 5TH AND 6TH PERIOD AND
ADJUSTED ONLY TO HIGH CHANCE POPS WITH SOME 1-2 INCH ACCUMULATIONS
IN THE HIGHEST TERRAIN. MOST OF THE PRECIP COMPLETED BY 00Z SUN AS
WAVE MOVES AWAY. SHOULD CONTINUE WITH DRY FORECAST SUNDAY THROUGH
MONDAY AWAITING NEXT MAJOR SYSTEM WHICH BEGINS TO IMPACT THE REGION
TUESDAY INTO WEDNESDAY WITH HIGHEST CHANCE POPS ON WEDNESDAY AS
SURFACE WAVE BUILDS NORTHEAST FROM THE WESTERN GULF OF MEXICO INTO
THE OHIO VALLEY. THIS SYSTEM LOOKS WARM ENOUGH FOR MAINLY RAIN WITH
SOME MENTION OF THE POSSIBILITY OF A SNOW SHOWER IN THE HIGHER
TERRAIN. TRENDED TEMPERATURE FORECAST TOWARD NEW MEX MOS GUIDANCE.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 41 49 35 48 33 / 30 10 10 10 30
KNOXVILLE MCGHEE TYSON AIRPORT, TN 45 47 34 46 32 / 50 10 10 10 20
OAK RIDGE, TN 42 48 34 46 31 / 50 10 10 10 20
TRI CITIES AIRPORT, TN 41 48 33 45 30 / 70 10 10 10 20
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...WIND ADVISORY UNTIL 1 AM EST THURSDAY FOR THE FOLLOWING ZONES:
CHEROKEE...CLAY.
TN...HIGH WIND WARNING UNTIL 1 AM EST THURSDAY FOR THE FOLLOWING
ZONES: BLOUNT SMOKY MOUNTAINS...COCKE SMOKY MOUNTAINS...
JOHNSON...MCMINN...NW BLOUNT...NORTH SEVIER...NORTHWEST
CARTER...NORTHWEST COCKE...NORTHWEST GREENE...NORTHWEST
MONROE...SEVIER SMOKY MOUNTAINS...SOUTHEAST CARTER...
SOUTHEAST GREENE...SOUTHEAST MONROE...SULLIVAN...UNICOI...
WASHINGTON TN.
WIND ADVISORY UNTIL 1 AM EST /MIDNIGHT CST/ THURSDAY FOR THE
FOLLOWING ZONES: ANDERSON...BLEDSOE...BRADLEY...CAMPBELL...
CLAIBORNE...EAST POLK...GRAINGER...HAMBLEN...HAMILTON...
HANCOCK...HAWKINS...JEFFERSON...KNOX...LOUDON...MARION...
MEIGS...MORGAN...RHEA...ROANE...SCOTT TN...SEQUATCHIE...
UNION...WEST POLK.
VA...HIGH WIND WARNING UNTIL 1 AM EST THURSDAY FOR THE FOLLOWING
ZONES: WASHINGTON.
WIND ADVISORY UNTIL 1 AM EST THURSDAY FOR THE FOLLOWING ZONES:
LEE...RUSSELL...SCOTT...WISE.
&&
$$
