« Back
NWS Peachtree City, Ga » Text Product » MRX Area Forecast Discussion


Printer-friendly Version     Surrounding:  BMX  MRX  FFC  CAE  TAE  
Current Version              Previous Versions:   1  2  3  4  5  6  7  8  9  

Area Forecast Discussion

883
FXUS64 KMRX 301845
AFDMRX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
245 PM EDT THU OCT 30 2014

.SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...CURRENT SURFACE
ANALYSIS SHOWS AN AREA OF HIGH PRESSURE CENTERED OVER THE LOWER OHIO
AND TN RIVER VALLEYS...WITH A SEASONABLY MILD AIR MASS OVER THE
FORECAST AREA UNDER MOSTLY CLEAR SKIES. CLOUDS WILL INCREASE TONIGHT
AS AN UPPER-LEVEL SHORT WAVE SWINGS OVER THE TN RIVER VALLEY...AHEAD
OF AN AMPLIFYING LONG WAVE UPPER-LEVEL PATTERN. THESE CLOUDS MAY
EVENTUALLY INHIBIT MOST FOG FORMATION OVERNIGHT...BUT WILL CONTINUE
TO MENTION PATCHY FOG EVERYWHERE DUE TO THE WARM WATER TEMPS
POSSIBLY CREATING ANOTHER MORNING OF FOG ALONG THE WATERWAYS. THE
MAIN STORY DURING THIS FORECAST PERIOD WILL BE THE AMPLIFYING UPPER-
LEVEL LONG WAVE TROUGH OVER THE EASTERN HALF OF THE NATION...WHICH
WILL EVENTUALLY BECOME A CUT-OFF UPPER LOW MOVING SOUTHEASTWARD
RIGHT OVER THE FORECAST AREA. THIS DEEP UPPER TROUGH WILL PUSH A
STRONG COLD FRONT THROUGH THE FORECAST AREA FRIDAY AFTERNOON...WITH
TEMPS FALLING QUICKLY AS THE SUN SETS FRIDAY EVENING AND RAIN
QUICKLY CHANGING TO SNOW OVER THE HIGHER ELEVATIONS. WITH THE DEEP
UPPER LOW EXPECTED TO MOVE RIGHT OVER THE FORECAST AREA AFTER
MIDNIGHT ON FRIDAY NIGHT...LAPSE RATES WILL STEEPEN CONSIDERABLY
OVER THE FORECAST AREA WITH CONVECTIVE SNOWFALL (AND THUS HIGHER
SNOWFALL INTENSITIES) POSSIBLE LATE FRIDAY NIGHT AND EARLY SATURDAY
MORNING. WHILE SNOW WILL LIKELY BE OBSERVED MOST EVERYWHERE (EVEN IN
THE VALLEYS) LATE FRIDAY NIGHT AND SATURDAY MORNING...SNOWFALL
ACCUMULATIONS SHOULD BE VERY ELEVATION-DEPENDENT DUE TO THE WARM
GROUND TEMPS IN THE LOWER ELEVATIONS. IT STILL APPEARS THAT 4 TO 8
INCHES WILL BE POSSIBLE OVER THE HIGHER ELEVATIONS ABOVE 2500 FEET
MSL...BUT A FOOT OR MORE OF SNOWFALL APPEARS POSSIBLE OVER THE
HIGHEST PEAKS ABOVE 5000 FEET DUE TO THE DIRECT PASSAGE OF THE DEEP
UPPER LOW AND ITS VERY COLD TEMPS ALOFT. SINCE THE MODELS HAVE BEEN
CONSISTENT WITH THIS PATTERN FOR SEVERAL RUNS...WILL GO AHEAD AND
UPGRADE THE WATCH TO A WINTER STORM WARNING. AS FOR TEMPS...GFS AND
NAM GUIDANCE NUMBERS ARE IN GENERAL AGREEMENT THROUGH SATURDAY
NIGHT...BUT WILL COMPROMISE WHERE SOME DIFFERENCES ARE NOTED.

.LONG TERM /SUNDAY THROUGH THURSDAY/...SOME LOW CLOUD COVER MAY
LINGER THROUGH THE MORNING HOURS ON SUNDAY ON THE BACKSIDE OF THE
DEPARTING LOW...BUT CLEARING WILL OCCUR BY THE AFTERNOON AND
EVENING AS HIGH PRESSURE BEGINS TO BUILD IN. ANOTHER FREEZE
/POSSIBLY A HARD ONE IN SW VA/ WILL BE POSSIBLE ACROSS THE NORTHERN
AND CENTRAL VALLEYS EARLY MONDAY MORNING. HOWEVER...WITH WINDS
INCREASING FROM THE SOUTH AND AMPLE SUNSHINE PREVAILING...A WARM-UP
BACK INTO THE MID TO UPPER 60S FOR MONDAY AND TUESDAY HIGH
TEMPERATURES ARE EXPECTED...WITH LOWS IN THE UPPER 30S AND 40S IN
MOST SPOTS. ANOTHER TROUGH/COLD FRONT LOOKS TO APPROACH THE AREA
TUESDAY NIGHT INTO WEDNESDAY...GIVING THE REGION ANOTHER SHOT AT
SOME PRECIPITATION FOR THE MIDDLE OF THE WEEK. MODELS STILL DIFFER
IN THE EXACT TIMING...BUT IT APPEARS THE BEST WINDOW MAY BE
WEDNESDAY AND WEDNESDAY EVENING...SO HAVE THE HIGHEST POPS DURING
THIS TIME PERIOD...BEFORE CLEARING THINGS OUT BY THURSDAY.
&&

.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN             41  60  35  49 /   0  30  20  20
KNOXVILLE MCGHEE TYSON AIRPORT, TN  40  57  34  46 /   0  60  60  60
OAK RIDGE, TN                       40  58  34  47 /   0  60  50  50
TRI CITIES AIRPORT, TN              36  53  32  43 /   0  80  90  90
&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...WINTER STORM WARNING FROM 8 PM FRIDAY TO 8 PM EDT SATURDAY FOR
     BLOUNT SMOKY MOUNTAINS-COCKE SMOKY MOUNTAINS-JOHNSON-SEVIER
     SMOKY MOUNTAINS-SOUTHEAST CARTER-SOUTHEAST GREENE-UNICOI.

VA...WINTER STORM WARNING FROM 8 PM FRIDAY TO 8 PM EDT SATURDAY FOR
     RUSSELL-WASHINGTON-WISE.
&&

$$

DMG/AMP



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.