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

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453
FXUS64 KMRX 122028
AFDMRX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
328 PM EST FRI FEB 12 2016

.SHORT TERM...(TONIGHT THROUGH SATURDAY)...SNOW DRIVEN BY SYNOPTIC
FORCING TODAY WILL BE EXITING THE AREA...BUT ADDITIONAL SNOW
SHOWERS WILL DEVELOP THIS EVENING AS A SURGE OF ARCTIC AIR BUILDS
IN FROM THE NORTHWEST. 925-850MB FLOW TRAJECTORIES SHOW A
CONNECTION TO LAKE MICHIGAN...AND THE NAM SHOWS LOW LEVEL CAPE
VALUES OF 100-150 J/KG THAT WILL HELP GENERATE SCATTERED TO
NUMEROUS SNOW SHOWERS IN NORTHERN SECTIONS. AN UPSLOPE 25-30 KT
WIND WILL ENHANCE ACCUMULATIONS IN HIGHER ELEVATIONS. ADDITIONAL
SNOW ACCUMULATIONS OF 1-3 INCHES CAN BE EXPECTED IN THE TN MTNS AND
SW VA...SO THE ADVISORY WILL BE MAINTAINED IN THOSE AREAS. WILL END
THE ADVISORY WITH THE NEW FORECAST PACKAGE FOR THE PLATEAU AND TN
VALLEY AREAS. WILL HOIST A WIND CHILL ADVISORY FOR THE MTNS AND FOR
WISE...RUSSELL...AND WASHINGTON VA AS WIND CHILLS WILL DROP INTO
THE -5 TO -15 RANGE FROM MIDNIGHT TO NOON TOMORROW. HIGHS TOMORROW
WILL BE IN THE 20S NORTH/CENTRAL TO LOWER/MID 30S SOUTH.

LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)... WINTER CONTINUES IN
FULL FORCE SATURDAY NIGHT AS COLD ARCTIC AIR MASS AND MOSTLY CLEAR
SKIES SATURDAY EVENING AND LIGHT SNOW COVER STILL POSSIBLE WILL
ALLOW OPTIMAL COOLING. LOWS EXPECTED TO BE IN THE SINGLE DIGITS AND
TEENS. UPPER TROUGH REMAINS OVER THE EASTERN STATES THROUGH MID WEEK
AND ANOTHER WEATHER SYSTEM WILL APPROACH THE AREA SUNDAY AFTERNOON.
MODELS ARE SPEEDING THIS SYSTEM UP A FEW HOURS SO INCREASED POPS
SUNDAY IN THE AFTERNOON. A SHORTWAVE MOVES OUT OF THE MS VALLEY
SUNDAY WITH INCREASING MOISTURE COMING IN ON BACK SIDE OF ARCTIC
HIGH. TEMPERATURES WILL BE MODERATING FROM A COLD MORNING BUT
TRAPPED COLD AIR SHOULD RESULT IN SOME LIGHT SNOW ON THE NORTHERN
PLATEAU AND SOUTHWEST VIRGINIA SPREADING INTO THE CENTRAL VALLEY
LATE IN THE DAY ONLY EXPECTING A FEW TENTHS ACCUMULATION. MAIN AXIS
OF PRECIPITATION WITH THE SYSTEM MOVES IN SUNDAY NIGHT AND MONDAY.

WITH THE WARM ADVECTION PATTERN AHEAD OF THIS SYSTEM A MIXED BAG OF
PRECIPITATION IS POSSIBLE SUNDAY NIGHT AND MONDAY. HIGHS SUNDAY IN
THE SOUTHERN PART OF THE AREA SHOULD REACH THE MID 30S TO AROUND 40.
OVERNIGHT SUNDAY NIGHT TEMPERATURES WILL BE SLOW TO FALL WITH THE
WARM AIR MOVING IN BUT ENOUGH WARM AIR WILL BE IN PLACE FOR SOME
FREEZING RAIN OR SLEET TO FALL IN SUB FREEZING AREAS OUTSIDE OF THE
NORTHERN AREAS WHERE THERE WILL BE MOSTLY SNOW. LIGHT RAIN WILL BE
PREVALENT IN WARMER AREAS OF THE SOUTHERN VALLEY. ON MONDAY THIS
PROCESS WILL CONTINUE IN THE MORNING BUT SHIFT FARTHER NORTHEAST AND
TOWARD THE APPALACHIANS WITH RAIN REPLACING WINTER PRECIPITATION
FROM THE SOUTHWEST TO NORTHEAST. PREFER THE MUCH COLDER MAX
TEMPERATURES OF THE GFS FOR HIGHS MONDAY MOSTLY MID 30S TO NEAR 40.
ICING FROM ABOUT 0.1 TO 0.25 INCHES IS POSSIBLE SUNDAY NIGHT AND
MONDAY MORNING BEFORE TEMPERATURES WARM ABOVE FREEZING ESPECIALLY
SOUTHERN PLATEAU...AND EASTERN TN MOUNTAIN VALLEYS WHERE COLD AIR
BECOMES TRAPPED.

SIGNIFICANT SNOWFALL IS POSSIBLE IN THE EASTERN MOUNTAINS AND
NORTHERN TENNESSEE COUNTIES AS WELL AS SW VIRGINIA WHERE THE
ATMOSPHERIC PROFILE IS COLDER SUNDAY NIGHT AND WARMS UP LATER
MONDAY. THE SYSTEM WILL SHIFT TO THE EAST MONDAY NIGHT AND TUESDAY
AND COLDER AIR WILL GRADUALLY BE PULLED SOUTH INTO THE FORECAST
AREA. THE RAIN WILL CHANGE OVER TO A WET SNOW LATER MONDAY NIGHT
INTO TUESDAY MORNING. BY AFTERNOON TUESDAY TEMPERATURES WARM ABOVE
FREEZING TO THE 40S LOWER ELEVATIONS AND SNOW WILL CHANGE TO RAIN
EXCEPT AT HIGHER MOUNTAIN LOCATIONS WHICH SHOULD GET MORE MEASURABLE
WET SNOW.

ANOTHER QUICK MOVING SYSTEM MOVES SOUTHEAST THROUGH THE UPPER TROUGH
TUESDAY NIGHT AND WEDNESDAY. THIS KEEPS THE THREAT FOR SNOW SHOWERS
AT NIGHT AND RAIN DURING THE DAY. THE UPPER TROUGH FINALLY SHIFTS
EAST WITH UPPER LEVEL RIDGING MOVING IN THURSDAY AND FRIDAY.
TEMPERATURES WILL BE CONSIDERABLY WARMER DURING THE DAY WITH SUN
RETURNING. HIGHS THURSDAY EXPECTED TO BE IN THE MID 40S NORTH TO
UPPER 50S SOUTH...THEN 50S TO LOWER 60S FRIDAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN             23  35  20  41 /   0   0   0  20
KNOXVILLE MCGHEE TYSON AIRPORT, TN  20  27  15  36 /  10   0   0  30
OAK RIDGE, TN                       19  29  15  37 /  10   0   0  30
TRI CITIES AIRPORT, TN              17  22   9  31 /  40  20   0  30

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...WINTER WEATHER ADVISORY UNTIL 4 AM EST SATURDAY FOR BLOUNT SMOKY
     MOUNTAINS-COCKE SMOKY MOUNTAINS-JOHNSON-SEVIER SMOKY
     MOUNTAINS-SOUTHEAST CARTER-SOUTHEAST GREENE-UNICOI.

     WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON EST SATURDAY
     FOR BLOUNT SMOKY MOUNTAINS-COCKE SMOKY MOUNTAINS-JOHNSON-
     SEVIER SMOKY MOUNTAINS-SOUTHEAST CARTER-SOUTHEAST GREENE-
     SOUTHEAST MONROE-UNICOI.

VA...WINTER WEATHER ADVISORY UNTIL 4 AM EST SATURDAY FOR LEE-RUSSELL-
     SCOTT-WASHINGTON-WISE.

     WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON EST SATURDAY
     FOR RUSSELL-WASHINGTON-WISE.

&&

$$

DGS/TD



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