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

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FXUS64 KMRX 262026
AFDMRX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
326 PM EST MON JAN 26 2015

.SHORT TERM...(TONIGHT AND TUESDAY)...BASED ON CALLS TO SMOKY MTN
PARK HEADQUARTERS...SNOW STILL APPEARS TO BE MAINLY OCCURRING ABOVE
3000 FEET. NEWFOUND GAP OBSERVATIONS INDICATE THE RATE OF SNOW
ACCUMULATION HAS SLOWED WITH AROUND 5 INCHES TOTAL FOR SNOW DEPTH.

HOWEVER...LOOKING UPSTREAM WE DO SEE AN AREA OF POTENTIAL SNOW
DEVELOPMENT OVER WRN KY AND NRN MIDDLE TN. MODELS SEEM TO BE
SPREADING THIS ACTIVITY E AND SE OVERNIGHT AS VORTICITY CHANNELS
ACROSS THE REGION. FORECAST SOUNDINGS SHOW AN INCREASE IN MOISTURE
LATER TONIGHT INTO TUESDAY MORNING...WITH TOP OF SATURATED COLUMN
MARGINALLY COLD ENOUGH TO PROMOTE SNOW CRYSTAL GROWTH (AROUND -10
DEGS C). LIGHT QPF PROGGED TO HUG THE TN-NC LINE AT LEAST THROUGH
12Z TO 15Z TUESDAY...SO AGREED TO EXTEND OUR WINTER WEATHER
ADVISORY THROUGH NOON TUESDAY...IN LINE WITH RNK AND GSP GRIDS.

OTHERWISE...LITTLE CHANGES TO FORECAST GRIDS FOR TUESDAY WITH SNOW
TAPERING OFF TO FLURRIES OR ENDING AFTER 18Z. SLIGHTLY LOWERED BOTH
MIN TEMP GRID FOR TONIGHT AND MAX TEMP GRID ON TUESDAY...SIMILAR TO
THE COLDER MOS TEMPS.


.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)...TUESDAY NIGHT...DRY AIR
WILL MOVE IN AS HIGH PRESSURE BUILDS IN TO THE AREA. MODELS STILL
SHOW ENOUGH MOISTURE IN THE HIGHER ELEVATIONS TO SEE A FEW FLURRIES
TUESDAY NIGHT THROUGH EARLY WEDNESDAY MORNING. WEDNESDAY AND
WEDNESDAY  NIGHT LOOK TO BE MOSTLY CLEAR WITH TEMPERATURES A COUPLE
OF DEGREES BELOW NORMAL THANKS TO THE HIGH PRESSURE.

THE NEXT SYSTEM IS EXPECTED TO APPROACH THE AREA THURSDAY MORNING.
MODELS ARE IN SLIGHT DISAGREEMENT ON TIMING OF THE PRECIP...WITH GFS
BRINGING IN THE PRECIP EARLY IN THE MORNING WHILE TEMPERATURES ARE
STILL BELOW FREEZING. HAVE GONE WITH A SLIGHT CHANCE FOR SNOW
SHOWERS A COUPLE OF HOURS IN THE EARLY MORNING THURSDAY...CHANGING
TO RAIN SHOWERS BY MID MORNING AS TEMPS WARM UP. RAIN WILL THEN
CHANGE TO SNOW AS TEMPERATURES LOWER THURSDAY NIGHT WITH THE SUN`S
SETTING...AND BY FRIDAY MORNING...A NORTHWEST FLOW PATTERN WILL SET
UP WITH SNOW SHOWERS MAINLY IN THE HIGHER ELEVATIONS...SW VA...AND
NE TN. ALL PRECIP IS EXPECTED TO BE GONE BY FRIDAY LATE AFTERNOON AS
DRY AIR AND HIGH PRESSURE SETTLE IN FOR A NICE START TO THE WEEKEND.

ANOTHER INTIMIDATING LOW PRESSURE WILL SWING ACROSS THE GREAT LAKES
SATURDAY NIGHT THROUGH SUNDAY...BRINGING OUR NEXT CHANCE FOR
SNOWFALL ACCUMULATION. MODELS ARE STRUGGLING WITH THIS
SYSTEM...WHICH THEY HAVE BEEN FOR ALMOST EVERY SINGLE SYSTEM THIS
WINTER...THIS FAR OUT. THE MOISTURE ASSOCIATED WITH THIS SYSTEM IS
LIGHT...BUT THERE SEEMS TO BE ENOUGH ALIGNMENT WITH BELOW FREEZING
TEMPS TO NEED TO INCLUDE SNOW ACCUMULATION IN THE GRIDS. WOULD
EXPECT THE HIGHEST ACCUMULATIONS TO BE IN THE HIGHER ELEVATIONS DUE
TO THE NORTHWEST PATTERN THAT IS EXPECTED TO SET UP...BUT AM
HESITANT TO SAY THIS SYSTEM`S FORECAST WITH MUCH CONFIDENCE...SEEING
AS HOW THE MODELS HAVE STRUGGLED WITH SNOWFALL SYSTEMS THIS FAR OUT
IN TIME. TEMPERATURES THROUGH THIS TIME WILL BE A COUPLE OF DEGREES
BELOW NORMAL.


&&

.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN             31  46  28  48 /  20  10   0   0
KNOXVILLE MCGHEE TYSON AIRPORT, TN  29  41  22  44 /  30  20   0   0
OAK RIDGE, TN                       29  41  23  45 /  30  20   0   0
TRI CITIES AIRPORT, TN              26  37  18  41 /  30  30   0   0

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...WINTER WEATHER ADVISORY UNTIL 1 PM EST TUESDAY FOR BLOUNT SMOKY
     MOUNTAINS-COCKE SMOKY MOUNTAINS-JOHNSON-NORTHWEST CARTER-
     SEVIER SMOKY MOUNTAINS-SOUTHEAST CARTER-SOUTHEAST GREENE-
     SOUTHEAST MONROE-UNICOI.

VA...NONE.
&&

$$

TG/JW


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