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

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210
FXUS64 KMRX 102017
AFDMRX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
317 PM EST WED FEB 10 2016

.SHORT TERM (TONIGHT AND THURSDAY)...LIGHT SNOW IS BEING REPORTED
ACROSS EASTERN MO AND IA IN ASSOCIATION WITH AN UPPER LEVEL JET
STREAK AND CHANNELED VORT MAX. THE MODELS SHOW THIS JET PUSHING
INTO OUR AREA THIS EVENING...AND PRODUCE SOME LIGHT QPF WITH IT.
MOISTURE IS LIMITED BUT WITH TEMPERATURES SO COLD...THERE SHOULD BE
ENOUGH FOR SCATTERED TO ISOLATED SNOW SHOWERS TONIGHT. LESS THAN
ONE INCH ACCUMULATION IS EXPECTED. THE OTHER ISSUE TONIGHT WILL BE
WIND CHILL VALUES IN THE -5 TO -15 RANGE IN THE MOUNTAINS. THE WIND
CHILL ADVISORY LOOKS ON TRACK AND WILL BE CONTINUED THROUGH
TOMORROW MORNING. EARLY MORNING CLOUDS SHOULD BE ERODING THROUGH
THE LATE MORNING AS THE UPPER TROUGH AND JET MOVE EAST...AND WITH
PARTIAL AFTERNOON SUN...HIGHS IN THE CENTRAL AND SOUTHERN TN VALLEY
WILL REACH THE UPPER 30S TO MID 40S. NORTHERN AREAS WITH GREATER
SNOW COVER SHOULD STAY IN THE UPPER 20S TO MID 30S.

.LONG TERM (THURSDAY NIGHT THROUGH WEDNESDAY)...WILL REMAIN UNDER
THE INFLUENCE OF AN UPPER TROUGH AND NORTHWEST FLOW THURSDAY NIGHT
FOR DRY AND COLD CONDITIONS.  A SHORT WAVE RIDING ALONG THE UPPER
FLOW WILL MOVE ACROSS FAR NORTHERN AREAS OF THE MRX CWA ON FRIDAY.
THE ADDED MOISTURE AND LIFT ASSOCIATED WITH THE SHORT WAVE COMBINED
WITH THE COLD AIR IN PLACE AND WEAK UPSLOPE FLOW WILL PROVIDE
SCATTERED LIGHT SNOW SHOWERS ACROSS THE NORTHERN HALF OF THE AREA
WITH LIGHT ACCUMULATIONS POSSIBLE...ESPECIALLY OVER HIGHER
ELEVATIONS.  LIGHT UPSLOPE SNOW MAY CONTINUE INTO SATURDAY MORNING.
ANOTHER SURGE OF COLD AIR WILL PUSH IN SATURDAY AND SATURDAY NIGHT
WITH LOWS SATURDAY NIGHT EXPECTED TO FALL INTO THE TEENS AND EVEN
SOME SINGLE DIGITS ACROSS THE TN VALLEY.  BREEZY CONDITIONS ACROSS
HIGHER ELEVATIONS AND THE VERY COLD TEMPERATURES MAY CREATE WIND
CHILLS BELOW ZERO. BRIEF...WEAK RIDGING ON SUNDAY WILL ALLOW FOR A
MINOR WARM UP AND A DRY DAY. MAIN SYSTEM OF CONCERN THROUGH THE
EXTENDED IS A LOW PRESSURE SYSTEM PROGGED INTO THE AREA SUNDAY NIGHT
INTO MONDAY. MODELS IN POOR AGREEMENT AND RUN TO RUN CONSISTENCE
POOR AS WELL. CURRENT GFS FASTER...A BIT DRIER AND COLDER THAN THE
ECMWF. IF THE GFS SCENARIO IS CORRECT...WILL SEE A BAND OF SNOW
SHOWERS PUSH THROUGH SUNDAY NIGHT INTO MONDAY MORNING WITH
ACCUMULATING SNOWFALL SNOW CONTINUING THROUGH THE DAY.  THE ECMWF
MOVES THROUGH DURING THE DAY MONDAY. THIS SCENARIO BRING IN BRIEF
SOUTHERLY FLOW FOR MUCH GREATER MOISTURE AND WARMER TEMPERATURES
WHICH SHOULD TRANSLATE TO THE MAIN BAND OF PRECIP MOVING THROUGH AS
RAIN THEN TRANSITIONING INTO A MIX OF WINTRY PRECIP BEFORE TURNING
TO ALL SNOW MONDAY EVENING. EITHER SCENARIO SHOULD PRODUCE
ACCUMULATING SNOWFALL BUT THE CONFIDENCE VERY LOW ON DETAILS. BEHIND
THE SYSTEM...ANOTHER SHOT OF COLD AIR AND A FEW LINGERING SHOWERS
EXPECTED TUESDAY AND MODERATING CONDITIONS FOR WEDNESDAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN             25  44  27  50 /  30   0   0  10
KNOXVILLE MCGHEE TYSON AIRPORT, TN  23  38  23  44 /  30   0   0  10
OAK RIDGE, TN                       22  39  22  43 /  30   0   0  10
TRI CITIES AIRPORT, TN              15  32  17  38 /  20  10   0  40

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR CHEROKEE-
     CLAY.

TN...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR BLOUNT
     SMOKY MOUNTAINS-COCKE SMOKY MOUNTAINS-JOHNSON-SEVIER SMOKY
     MOUNTAINS-SOUTHEAST CARTER-SOUTHEAST GREENE-SOUTHEAST
     MONROE-UNICOI.

     WIND CHILL ADVISORY UNTIL NOON EST THURSDAY FOR BLOUNT SMOKY
     MOUNTAINS-COCKE SMOKY MOUNTAINS-JOHNSON-SEVIER SMOKY
     MOUNTAINS-SOUTHEAST CARTER-SOUTHEAST GREENE-SOUTHEAST
     MONROE-UNICOI.

     WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR EAST
     POLK-HANCOCK-HAWKINS-NORTHWEST CARTER-NORTHWEST GREENE-
     SULLIVAN-WASHINGTON TN.

VA...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR LEE-
     RUSSELL-SCOTT-WASHINGTON-WISE.

&&

$$

DGS/MJB



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