FXUS63 KJKL 160737
AFDJKL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
237 AM EST WED DEC 16 2009

.SHORT TERM.../TODAY THROUGH FRIDAY NIGHT/...UPDATED

ONLY A FEW MINOR ADJUSTMENTS WERE MADE TO THE FIRST FIVE PERIODS OF
THE FORECAST. THE PRIMARY CHANGE MADE TO THE SHORT TERM PORTION OF
THE FORECAST WAS TO INCREASE FRIDAYS HIGH TEMPERATURES BY 6 OR 7
DEGREES...AS THE LATEST FORECAST MOS DATA AND MODEL SOUNDINGS BOTH
CAME IN WITH AFTERNOON MAX TEMPERATURES MANY DEGREES WARMER THAN WHAT
WAS IN THE PREVIOUS FORECAST. THE NAM12...GFS...CANADIAN...AND ECMWF
MODELS ALL AGREE THAT STRONG HIGH PRESSURE WILL KEEP A COLD DRY AIR
MASS IN PLACE THROUGH THE END OF THE WEEK. A WEAK TROUGH WILL PUSH AN
AREA OF MIDDLE AND HIGH LEVEL CLOUD COVER ACROSS THE AREA ON
THURSDAY. ASIDE FROM THAT...THE WEATHER WILL BE CALM WITH MOSTLY
CLEAR SKIES...COOL TEMPERATURES...AND LIGHT WINDS.

.LONG TERM.../FRIDAY THROUGH TUESDAY/

THE LATEST RUNS OF THE ECMWF AND GFS MODELS BOTH ARE REVEALING A MUCH
MORE FAVORABLE PATTERN FOR A LIGHT ACCUMULATING SNOWFALL EVENT ON
SATURDAY NIGHT INTO SUNDAY. THE LATEST MODELS HAVE A FETCH OF ATLANTIC
MOISTURE MOVING INTO EASTERN KENTUCKY FRIDAY NIGHT AND SATURDAY...AS
AN AREA OF LOW PRESSURE MOVES UP THE COAST...AND A VIGOROUS SHORT
WAVE TROUGH MOVES ACROSS THE OHIO VALLEY. THE RESULT WILL BE A WIND
FLOW THAT WILL ALLOW MOISTURE FROM THE ATLANTIC OCEAN TO MAKE ITS WAY
INTO THE AREA BETWEEN THE TWO SYSTEMS. AN ADDITIONAL SHOT OF COLD AIR
WILL THEN MAKES ITS WAY INTO THE AREA ON SATURDAY. PERSISTENT
NORTHWEST WINDS WILL THEN SET UP LATE IN THE DAY SATURDAY...ALLOWING
FOR ANOTHER FETCH OF MOISTURE TO MIGRATE SOUTHEASTWARD OFF OF LAKE
MICHIGAN SATURDAY. THIS PATTERN TENDS TO LEAD TO PERSISTENT AND LONG
LIVED LIGHT SNOW EVENTS IN EASTERN KENTUCKY. IT LOOKS LIKE THE BEST
CHANCE FOR SNOW WILL OCCUR BETWEEN 0 AND 12Z ON SUNDAY...AS A STRONG
SHORT WAVE MOVES RIGHT OVER EASTERN KENTUCKY AND INTO THE CAROLINAS.
WITH EVERYTHING LOOKING PRETTY FAVORABLE FOR SNOW...DECIDED TO
INCREASE PRECIPITATION CHANCES ACROSS THE BOARD FOR
SATURDAY...SATURDAY NIGHT AND SUNDAY MORNING. MADE APPROPRIATED
ADJUSTMENTS TO QPF...WEATHER...AND SNOWFALL GRIDS BASED ON THE
CHANGES MADE TO THE POP FORECAST. ALSO INCREASED HUMIDITY VALUES OVER
THE WEEKEND...AS WIDESPREAD LOW AND MIDDLE LEVEL MOISTURE WILL BE
ENTRENCHED ACROSS THE AREA. THE REST OF THE EXTENDED FORECAST PAST
SUNDAY MORNING WAS LEFT AS IS.

&&

.AVIATION.../06Z TO 06Z/

MVFR STRATOCU WILL CONTINUE TO SCATTER OUT FROM NORTHWEST TO
SOUTHEAST THROUGH THE EARLY MORNING HOURS AS ARCTIC HIGH PRESSURE
AND ITS DRIER AIR MOVES DEEPER INTO THE REGION. ONCE THE LOW CLOUDS
CLEAR...VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD AND
BEYOND. NORTHWEST WINDS AT 5 TO 10 KTS INITIALLY WILL BECOME LIGHT
AND VARIABLE BENEATH THE HIGH LATER TODAY...CONTINUING INTO TONIGHT.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$
SHORT TERM...AR
LONG TERM...GEOGERIAN/AR
AVIATION...GREIF