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

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FXUS64 KMRX 282012
AFDMRX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
253 PM EST SUN DEC 28 2014

.SHORT TERM (TONIGHT AND MONDAY)...WEAK COLD FRONT ALONG CUMBERLAND
PLATEAU WILL MOVE SOUTHEAST THROUGH THE AREA THIS EVENING AND
THROUGH THE SOUTHERN APPALACHIANS OVERNIGHT. AREA OF RAIN HAS WAINED
ACROSS THE AREA AS MID LEVEL SPEED MAX HAS MOVED OFF TO THE NE.
ENTRANCE REGION OF UPPER LEVEL JET WILL KEEP RAIN GOING BEHIND COLD
FRONT THROUGH TONIGHT. PRECIPITATION WILL WEAKEN SOME OVERNIGHT.
POST FRONTAL COLD AIR VERY SHALLOW. BOUNDARY LAYER WILL REMAIN
SATURATED THROUGH MONDAY MORNING. AREAS OF FOG WILL CONTINUE
OVERNIGHT AND COULD BECOME DENSE WITH WEAK SURFACE FLOW. MID LEVEL
DRIES OUT ON MONDAY WHILE LOW LEVELS REMAIN VERY HUMID. LIGHT RAIN
OR DRIZZLE POSSIBLE INTO THE AFTERNOON HOURS. TEMPERATURES WILL
REMAIN ABOVE NORMAL.

.LONG TERM... SHOULD BE SOME REMNANT MOISTURE IN THE AREA OVERNIGHT
MONDAY INTO TUESDAY AS SOME UPPER LEVEL ENERGY MOVES ACROSS NORTH OF
THE AREA THAT COULD LEAD TO SOME ADDITIONAL LIGHT SHOWERS. WITH THE
SECONDARY COLD FRONT TEMPS WILL DEFINITELY COOL DOWN ACROSS THE
AREA. AFTER THE FRONT IS THROUGH THE AREA WE DRY OUT FOR A COUPLE OF
DAYS WITH VERY LITTLE WARMING THROUGH THE END OF THE WORK WEEK.

NEXT SYSTEM TO FOCUS ON WILL COME AFTER NEW YEARS DAY AS A LOW
PRESSURE SYSTEM MOVES ACROSS NEW MEXICO BEFORE THE MODELS START TO
DIVERGE IN WHAT TO DO WITH THE SYSTEM. GFS WANTS TO KICK OUT THE
SYSTEM AS THE TROUGH GOES NEGATIVELY TILTED WEST OF US LEADING TO
WARMER TEMPS AND A LATER ONSET OF PRECIP. WHILE THE ECMWF WANTS TO
BE MUCH SLOWER AND FURTHER SOUTH WITH THE SYSTEM, HAVING THE CENTER
OF THE LOW MOVE JUST NORTH OF THE AREA. TEMPS WILL BE COLD ENOUGH
OVERNIGHT FRIDAY THAT THE SYSTEM COULD HAVE SOME SNOW MIXED IN WITH
IT AS WELL. OF NOTE TO WATCH WITH THIS SYSTEM WILL BE A LOW LEVEL
JET FROM THE SOUTH/SOUTHWEST ON FRIDAY INTO SATURDAY WHICH WILL
BRING IN A VERY WARM LAYER OF AIR JUST ABOVE THE SURFACE. RIGHT NOW
ALL THE MODELS AND GUIDANCE ARE COMING IN WITH TEMPS ABOVE FREEZING
OVERNIGHT FRIDAY INTO SATURDAY...HOWEVER IF SYSTEM COMES IN STRONGER
THAN ANTICIPATED, LEADING TO COLDER SURFACE TEMPS, AND THE LOW LEVEL
JET IS STILL CRANKING, CAUSING A VERY WARM LAYER ABOVE THE SURFACE,
THE POTENTIAL FOR SOME FREEZING RAIN WILL BE PRESENT. AT THIS POINT
WILL NOT MENTION ANYTHING ABOUT FREEZING RAIN IN THE FORECAST AS ALL
GUIDANCE IS SUGGESTING IT WON`T HAPPEN, BUT WILL HAVE TO KEEP THIS
IN THE BACK OF OUR MINDS.

&&

.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN             42  52  39  53 /  90  20  10  10
KNOXVILLE MCGHEE TYSON AIRPORT, TN  40  50  37  48 /  90  30  20  10
OAK RIDGE, TN                       39  48  37  47 /  80  20  20  10
TRI CITIES AIRPORT, TN              41  47  37  46 /  90  40  30  20

&&

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

$$

SON/ABM


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