Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN

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FXUS64 KMRX 072019
AFDMRX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
319 PM EST SUN FEB 7 2016

.SHORT TERM (TODAY THROUGH TUESDAY)... WEATHER THROUGH THE
REMAINDER OF THE DAY WILL BE PLEASANT WITH MOSTLY SUNNY SKIES AND
HIGHS TOPPING OUT IN THE 50`S ACROSS MUCH OF THE AREA. THINGS WILL
QUICKLY START TO CHANGE OVERNIGHT AS A LOW MOVES ACROSS THE GREAT
LAKES REGION AND THE ASSOCIATED COLD FRONT SWEEPS THROUGH OUR AREA.
CLOUD COVERAGE WILL INCREASE AFTER THE SUN HAS SET AND
PRECIPITATION WILL MOVE IN FROM THE NORTHWEST. TEMPERATURES ALOFT WILL
COOL MUCH MORE QUICKLY COMPARED TO SURFACE TEMPS AND THIS WILL BE
THE BIGGEST CONCERN WITH REGARDS TO PRECIPITATION TYPE. IF THE
SURFACE COOLS OFF QUICKER WE WILL SWITCH TO SNOW MUCH FASTER, BUT
IF IT DOESN`T AND WE REMAIN SEVERAL DEGREES ABOVE FREEZING THEN IT
WILL LIKELY BE RAIN. MODELS ARE IN DISAGREEMENT WITH THE
TEMPERATURES NEAR THE SURFACE WITH THE GFS/NAM BEING MUCH COLDER
COMPARED TO THE ECMWF AND OTHER MODELS. THIS HAS LEAD TO A LOW
CONFIDENCE FORECAST WHEN IT COMES TO THE MONDAY MORNING COMMUTE AS
ONLY A COUPLE OF DEGREES COULD MEAN THE DIFFERENCE BETWEEN A WET
COMMUTE AND ONE THAT INVOLVES A COUPLE OF INCHES OF SNOW. WITH THAT
SATED, WE HAVE GONE AHEAD AND ISSUED A WINTER WEATHER ADVISORY FOR
EARLY MONDAY MORNING THROUGH TUESDAY NIGHT. IF TEMPERATURES REMAIN
WARM ENOUGH THEN PLACES IN THE ADVISORY AREA MIGHT NOT SEE SNOW
UNTIL MONDAY NIGHT...HOWEVER, IF SNOW MOVES IN FASTER OR
TEMPERATURES ARE SLIGHTLY COOLER THAN FORECASTED THEN THE MONDAY
MORNING COMMUTE COULD BE SNOWY IN SOME PLACES. SO WE HAVE ERRED ON
THE SIDE OF CAUTION AND STARTED THE ADVISORY IN THE MORNING ON
MONDAY. REGARDLESS, THE TEMPERATURES IN THE VALLEY WILL WARM ENOUGH
TO LIKELY SWITCH OVER TO RAIN DURING THE DAYTIME HOURS. WITH THE
STEEP LAPSE RATES AND COLD TEMPERATURES ALOFT, IT`S NOT OUT OF THE
QUESTION TO HEAR A RUMBLE OF THUNDER DURING THE DAY WITH THE
RAINFALL. TROUGH WILL REMAIN OVER THE AREA ALLOWING FOR VERY COLD
AIR TO CONTINUE TO INVADE INTO OUR REGION AND TEMPERATURES ON
TUESDAY WILL LIKELY REMAIN BELOW FREEZING FOR MANY PLACES. ANY
PRECIPITATION THAT DOES OCCUR ON MONDAY NIGHT INTO TUESDAY WILL
REMAIN IN THE FORM OF SNOW. QPF DOES LOOK LIGHT WITH THIS EVENT AND
THEREFORE WILL RESULT IN A RATHER SLOW SNOWFALL ACCUMULATION DURING
THE FIRST PART OF THE WEEK.

.LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...FRIGID WEATHER PATTERN
REMAINS IN PLACE WEDNESDAY INTO THURSDAY AS ADDITIONAL ENERGY DROPS
SOUTH THROUGH THE BASE OF THE EASTERN U.S. UPPER TROUGH.
TEMPERATURES WILL BE WELL BELOW NORMAL BOTH DAYS WITH MAXES
REMAINING BELOW FREEZING ACROSS NEARLY THE ENTIRE FORECAST AREA ON
WEDNESDAY AND OVER MUCH OF THE NORTHERN TWO THIRDS OF THE REGION ON
THURSDAY. LIGHT SNOWFALL STILL POSSIBLE TUESDAY NIGHT EVERYWHERE BUT
TRANSITIONS TO MORE OF AN OROGRAPHIC SITUATION IMPACTING MAINLY THE
HIGHER TERRAIN OVER SOUTHWEST VIRGINIA AND ALONG THE TENNESSEE AND
NORTH CAROLINA BORDER FOR WEDNESDAY. WEDNESDAY NIGHT INTO THURSDAY
THERE STILL MAY BE A FEW SNOW SHOWERS POSSIBLE IN THESE MOUNTAIN
LOCALES BUT ANY SNOW SHOULD BE OVER FOR THE REMAINDER OF THE
FORECAST AREA. MODELS NOT ENTIRELY ON THE SAME PAGE BUT STILL HINT
AT AN ALBERTA CLIPPER TYPE SYSTEM FOR THE POSSIBILITY OF SOME LIGHT
SNOW AGAIN FRIDAY INTO FRIDAY NIGHT. KEPT SLIGHT AND LOW CHANCE POPS
IN FOR THIS POSSIBILITY. SATURDAY AND SUNDAY APPEAR TO BE DRY AT
THIS TIME AS THE OFFENDING EASTERN TROUGH MAY FINALLY SHOW SOME
SIGNS OF SHIFTING OFF TO THE ATLANTIC.

&&

.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN             35  45  27  32 /  40  50  40  30
KNOXVILLE MCGHEE TYSON AIRPORT, TN  34  42  26  28 /  50  60  60  50
OAK RIDGE, TN                       33  43  25  30 /  60  60  50  40
TRI CITIES AIRPORT, TN              29  41  25  28 /  40  70  60  60

&&

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

$$

ABM/TH


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