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

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000
FXUS64 KMRX 050756
AFDMRX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
356 AM EDT THU MAY 5 2016

.SHORT TERM (TODAY THROUGH TONIGHT)...IMPRESSIVE LATE SEASON
LOW PRESSURE DROPPING DOWN INTO THE FORECAST AREA. CENTER OF UPPER
LOW WILL PASS DIRECTLY OVER NETN AND SWVA TO START THE PERIOD AND
BRING THE COLDEST 850 TEMPS THUS FAR FOR THIS EVENT. PROXIMITY TO
TROUGH BASE AND LOW CIRCULATION ALLOWS A STRONG VORTICITY FIELD TO
ROTATE THROUGH THE CWA. WITH THIS LOW ANOTHER BOUT OF MOISTURE ALSO
MOVES IN. MOISTURE COMBINED WITH GOOD UPPER LEVEL DYNAMICS WILL
ALLOW FOR LIKELY POPS ACROSS THE CENTRAL VALLEY EARLY IN THE PERIOD.
NAM ALONG WITH OTHER HI-RES SOUNDINGS SUPPORTIVE OF SNOW ABOVE
4000/4500 FEET AS THIS ACTIVITY MOVES THROUGH. PRECIP MOVES INTO THE
NORTHERN PLATEAU AROUND 12Z AND EXITS ACROSS OUR EASTERN MOUNTAINS
AROUND 21Z. BEST WINDOW FOR SNOW ACROSS THE HIGH PEAKS OF OUR
EASTERN MOUNTAINS LOOKS TO BE FROM 15Z THROUGH ABOUT 20/21Z. DURING
THIS STRETCH...ELEVATIONS ABOVE 5K FEET SHOULD PICK UP AROUND AN
INCH OF SNOW WITH LITTLE TO NO ACCUMULATION AROUND THE 4000/4500
FOOT MARK. AGAIN...SNOW OPPORTUNITY AND OVERALL PRECIP CHANCES
DECREASE AFTER 20/21Z AS THE CENTER OF THE LOW DROPS DOWN INTO THE
CAROLINAS. THIS WILL LEAVE US WITH A BREAK IN THE PRECIPITATION
DURING THE LATE AFTERNOON HOURS AND SOME PARTIAL CLEARING. AS THE
LOW MOVES FURTHER SOUTHEAST INTO THE CAROLINAS WRAP AROUND MOISTURE
BEGINS TO ENTER SWVA AND NETN. THIS IS WHERE PRECIP CHANCES WILL BE
HIGHEST OVERNIGHT. AS THIS WRAP AROUND MOISTURE MOVES IN THERE WILL
BE ANOTHER BRIEF OPPORTUNITY FOR SOME LIGHT SNOW ABOVE 5000
FEET...WITH UP TO HALF AN INCH OF ACCUMULATION POSSIBLE.

HIGH TEMPERATURES TODAY WILL RUN 15 TO 20 DEGREES BELOW NORMAL.
HIGHS WILL RANGE FROM THE LOW 60S SOUTHERN VALLEY TO UPPER 40S/LOW
50S ACROSS SWVA. OVERNIGHT LOWS EXPECTED TO BE A DEGREE OR TWO
WARMER THAN LAST NIGHT WITH LOWS IN THE LOW TO MID 40S.

.LONG TERM (FRIDAY THROUGH WEDNESDAY)...UNSEASONABLY COLD UPPER LOW
WILL BE LOCATED ACROSS THE MID-ATLANTIC STATES FRIDAY. THE COLD
AIR ALOFT...OROGRAPHIC LIFT...AND SOME LOW-LEVEL CONVERGENCE WILL
PRODUCE SCATTERED SHOWERS OVER SOUTHWEST VIRGINIA AND NORTHEAST
TENNESSEE.

THE UPPER LOW GETS PICKED UP BY A CANADIAN UPPER TROUGH. SHORT-WAVE
ENERGY FROM THE NORTHERN STREAM UPPER LOW WILL MOVE ACROSS THE OHIO
VALLEY ALONG WITH A FRONTAL BOUNDARY. THIS BOUNDARY WILL FOCUS
LIMITED INSTABILITY TO PRODUCE SCATTERED SHOWERS OVER SOUTHWEST
VIRGINIA...NORTHERN PLATEAU...AND NORTHEAST TENNESSEE FOR LATE
SATURDAY THROUGH SUNDAY.

FOR TUESDAY AND WEDNESDAY...UPPER FLOW BECOMES SOUTHWESTERLY WITH A
SERIES OF SHORT-WAVES MOVING ACROSS THE TENNESSEE VALLEY. SHOWERS
AND THUNDERSTORMS CAN BE EXPECTED. WILL NEED TO MONITOR HOW MUCH
MOISTURE AND INSTABILITY ADVECTS INTO THE TENNESSEE VALLEY. STRONG
TO SEVERE STORMS ARE POSSIBLE.

&&

.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN             63  47  73  50 /  30  10   0   0
KNOXVILLE MCGHEE TYSON AIRPORT, TN  57  46  69  49 /  60  50  10  10
OAK RIDGE, TN                       58  46  70  49 /  60  30  10   0
TRI CITIES AIRPORT, TN              55  43  63  46 /  80  70  40  20

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&

$$




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