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

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FXUS64 KMRX 082026
AFDMRX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
326 PM EST MON FEB 8 2016

.SHORT TERM (TONIGHT THROUGH WEDNESDAY)...VERY BUSY UPPER NORTHWEST
FLOW BRINGING PERIODS OF LIFT AND WEAK INSTABILITY OVER COOL/MOIST
AIR MASS.

CROSS SECTION ACROSS THE MOUNTAINS SHOWING LIFT...MOISTURE...UPSLOPE
WIND...AND DENDRITIC TEMPS ON WINDWARD SIDE OF APPALACHIANS THROUGH
WEDNESDAY. WILL CONTINUE WITH WINTER STORM WARNING IN THAT
AREA...ALSO WILL START A WIND CHILL ADVISORY IN THIS SAME AREA
STARTING TUESDAY 6PM THROUGH NOON ON THURSDAY.  STEADY WIND CHILLS
IN THE MOUNTAINS FOR MOST OF THAT TIME IN THE -5 TO -15 RANGE.

HAVE SHAVED BACK SLIGHTLY ON OVERALL SNOW AMOUNTS...AS PARAMETERS
DON`T LOOK QUITE AS STRONG NOW...BUT STILL A LONG FETCH OF COLD
MOIST AIR WITH WEAK LIFT AND INSTABILITY THROUGH WEDNESDAY FOR AT
LEAST PARTS OF THE AREA. WENT VERY CLOSE TO GUIDANCE TEMPS.

.LONG-TERM (WEDNESDAY NIGHT THROUGH MONDAY)...
THE FORECAST REMAINS COLD INTO THE EXTENDED WITH NORTHWESTERLY
FLOW CONTINUING ACROSS THE AREA. THE ATMOSPHERE REMAINS EXTREMELY
DRY WITH PW VALUES GENERALLY LESS THAN A QUARTER OF AN INCH
WEDNESDAY NIGHT. HOWEVER...THE PERSISTENT NW FLOW WILL BE
SUFFICIENT ENOUGH FOR A FEW LIGHT SNOW SHOWERS TO CONTINUE ACROSS
THE HIGH TERRAIN ALONG THE TN/NC BORDER AND INTO SW VA. AGAIN...THE
MAIN STORY WILL BE THE COLD..WIND CHILL READINGS WILL RANGE FROM
-15 TO -5 ACROSS THE HIGHER TERRAIN ALONG THE TN/NC LINE AND SW VA
ON WEDNESDAY NIGHT INTO THURSDAY MORNING. WIND CHILL READINGS
ACROSS THE VALLEY WILL BE IN THE SINGLE DIGITS. LOW TEMPERATURES ON
THURSDAY MORNING WILL RANGE FROM NEAR 0 ACROSS THE MOUNTAIN TO THE
LOWER TEENS ACROSS THE SOUTHERN VALLEY.

MODELS ARE ALL OVER THE PLACE FOR THE REMAINDER OF THE EXTENDED
PERIOD. THE NAM AND GEM SHOW A FRONTAL BOUNDARY TO THE SOUTH AND
WEST ON THURSDAY. THEY BOTH SHOW A SHORTWAVE TROUGH THAT DIVES OUT
OF THE NORTHERN PLAINS AND LEADS TO A FEW SCATTERED SNOW SHOWERS
ACROSS THE AREA. THE GFS AND ECMWF SHOW A WEAKER WAVE WITH NO
PRECIP. FOR NOW...HAVE KEPT THINGS DRY ON THURSDAY BUT THERE
CONTINUES TO BE A WIDE VARIETY OF MODEL SOLUTIONS.

THE CLOSED UPPER LOW CONTINUES IN PLACE ACROSS THE NORTHEASTERN U.S.
LATE IN THE WEEK. THE MODELS INDICATES ANOTHER SHORTWAVE TROUGH
ROTATING THROUGH THIS LARGER SCALE WAVE. THE ECMWF INDICATES DECENT
COVERAGE OF SNOW SHOWERS ON FRIDAY AS ANOTHER REINFORCING SHOT OF
COLD AIR MOVES IN WITH THE SYSTEM. THE GFS...GEM AND ECMWF INDICATE
SOME WESTERLY TO SOUTHWESTERLY FLOW IN THE LOW LEVELS AHEAD OF THIS
FRONT AND THE WARM AIR ADVECTION COULD BE STRONG ENOUGH TO PUSH
TEMPERATURES INTO THE MID 30S TO LOW 40S AREAWIDE. THE REASON THIS
IS SIGNIFICANT...IS BECAUSE THIS IS OUR BEST CHANCE AT GETTING ABOVE
FREEZING FOR THE REMAINDER OF THE FORECAST PERIOD. SINCE THERE IS
STILL SO MUCH MODEL INCONSISTENCY WITH AMOUNT OF MOISTURE...HAVE
CONTINUED WITH SLIGHT CHANCE TO CHANCE POPS FRIDAY INTO FRIDAY NIGHT
WITH BEST CHANCES IN THE HIGHER ELEVATIONS. CONTINUED WITH A SLIGHT
CHANCE FOR NORTHWEST FLOW SNOW SHOWERS ON SATURDAY ACROSS THE HIGH
TERRAIN AS ARCTIC AIR IS RE-INTRODUCED TO THE REGION. HIGHS ON
SATURDAY WILL TOP OUT BELOW FREEZING IN MOST LOCATIONS WITH MID 30S
ACROSS THE SOUTHERN VALLEY.

SUNDAY MORNING WILL BE ANOTHER BITTERLY COLD MORNING ACROSS THE AREA
WITH LOWS IN THE SINGLE DIGITS TO LOWER TEENS. HIGH PRESSURE AND
LIGHT WINDS SHOULD ALLOW FOR TEMPERATURES TO DROP RAPIDLY. IF THERE
IS SNOW COVER ON THE GROUND...EXPECT TEMPERATURES WOULD BE ANOTHER 5-
10 DEGREES COOLER. THE MODELS INDICATE ANOTHER SYSTEM MOVING IN
EARLY NEXT WEEK WITH ARCTIC AIR ALREADY IN PLACE. THE INTENSITY OF
THIS SYSTEM ON THE GFS/ECMWF IS SOMETHING THAT WILL NEED TO BE
WATCHED FOR A MORE SUBSTANTIAL SNOWFALL ACROSS THE REGION.

&&

.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN             28  34  22  32 /  50  50  20  10
KNOXVILLE MCGHEE TYSON AIRPORT, TN  26  31  21  28 /  70  70  30  10
OAK RIDGE, TN                       26  32  21  28 /  70  70  30  20
TRI CITIES AIRPORT, TN              25  29  20  24 /  90  70  40  40

&&

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

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

     WIND CHILL ADVISORY FROM 6 PM TUESDAY TO 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 AM EST /6 AM CST/ WEDNESDAY FOR
     ANDERSON-BLEDSOE-GRAINGER-HAMBLEN-JEFFERSON-KNOX-LOUDON-
     MARION-NW BLOUNT-NORTH SEVIER-NORTHWEST COCKE-NORTHWEST
     MONROE-RHEA-ROANE-SEQUATCHIE-UNION.

     WINTER WEATHER ADVISORY UNTIL 7 PM EST TUESDAY FOR BRADLEY-
     HAMILTON-MCMINN-MEIGS-WEST POLK.

     WINTER WEATHER ADVISORY UNTIL 7 PM EST WEDNESDAY FOR CAMPBELL-
     CLAIBORNE-EAST POLK-HANCOCK-HAWKINS-MORGAN-NORTHWEST CARTER-
     NORTHWEST GREENE-SCOTT TN-SULLIVAN-WASHINGTON TN.

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

&&

$$

GM/MA


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