Area Forecast Discussion
Issued by NWS Jackson, KY

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KJKL 191845 AAA
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON KY
145 PM EST FRI DEC 19 2014

.UPDATE...
ISSUED AT 145 PM EST FRI DEC 19 2014

DID A QUICK UPDATE TO FINE TUNE HIGH TEMPERATURES AND SKY COVER
THROUGH THE REST OF THE AFTERNOON. ALSO NUDGED HOURLY TEMPERATURES
PER THE LATEST OBS AND TRENDS. THESE HAVE BEEN SENT TO THE NDFD AND
WEB SERVERS.

UPDATE ISSUED AT 1050 AM EST FRI DEC 19 2014

15Z SFC ANALYSIS SHOWS HIGH PRESSURE IN PLACE OVER THE WESTERN OHIO
VALLEY AND UPPER MIDWEST. TO THE SOUTH A WEAK LOW IS FOUND IN THE
NORTHWESTERN GULF OF MEXICO. LOCALLY...LOW CLOUDS PLAGUE MUCH OF THE
CWA MAINLY IN THE NORTH AND EAST PORTIONS...BENEATH ARRIVING MID
LEVEL CLOUDS FROM THE SOUTHWEST. TEMPERATURES ARE GENERALLY IN THE
UPPER 20S NORTH TO MID 30S SOUTH WHILE DEWPOINTS ARE IN THE MID 20S
WITH LIGHT NORTH WINDS. HAVE UPDATED THE GRIDS MAINLY TO FINE TUNE THE
SKY COVER AND ALSO THE HOURLY T/TD ONES PER THE LATEST OBS...
TRENDS...AND BCCONSSHORT GUIDANCE. THE FRESHENED GRIDS HAVE BEEN SENT
TO THE NDFD AND WEB SERVERS.

UPDATE ISSUED AT 733 AM EST FRI DEC 19 2014

THE FORECAST HAS BEEN ON TRACK SO FAR THIS MORNING. SATELLITE IMAGERY
SHOWING THAT CLOUD COVER IS FINALLY STARTING TO BREAK UP A BIT ACROSS
THE AREA. THIS TREND SHOULD CONTINUE THROUGH EARLY THIS AFTERNOON
BEFORE MORE CLOUDS BEGIN MOVING IN FROM THE SOUTHWEST AHEAD OF AN
APPROACHING WEATHER SYSTEM. THE LATEST HOURLY OBS DATA WAS INGESTED
INTO THE FORECAST GRIDS TO ESTABLISH NEW TRENDS AND FRESHEN UP THE
DATA. ASIDE FROM THAT NO OTHER CHANGES WERE MADE OR NECESSARY.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 300 AM EST FRI DEC 19 2014

THE SHORT TERM PERIOD OF THE FORECAST WILL START OFF RATHER QUIET AS
WEAK RIDGE OF LOW PRESSURE ALOFT REMAINS SITUATED OVER THE REGION.
LOW AND MIDDLE LEVEL CLOUD COVER WILL REMAIN TRAPPED BENEATH THE
SUBSIDENCE INVERSION ASSOCIATED WITH THE RIDGE THROUGH THE DAY TODAY.
THESE CLOUDS WILL GRADUALLY BREAK UP AND MOVE OFF TO THE EAST AS
ANOTHER WEATHER SYSTEM TAKING SHAPE OVER THE SOUTHERN PLAINS BEGINS
TO MOVE IN OUR DIRECTION. THIS NEXT WEATHER SYSTEM IS EXPECTED TO
BEGIN AFFECTING OUR FAR SOUTHWESTERN COUNTIES SOMETIME DURING THE PRE
DAWN HOURS ON SATURDAY. MOIST AIR FROM THE GULF OF MEXICO WILL MOVE
INTO THE AREA ON THE NORTHERN FRINGE OF AN AREA OF LOW PRESSURE THAT
WILL PASS BY TO OUR SOUTH. THE TREND IN THE MODEL DATA THE PAST FEW
RUNS HAS BEEN TO MOVE THIS LOW FURTHER AND FURTHER SOUTH OF OUR AREA.
THAT BEING SAID...THE NEW FORECAST WAS TRENDED IN THIS DIRECTION
BASED ON THE LATEST MODEL CONSENSUS. THE AMOUNT OF COLD AIR
ASSOCIATED WITH THE LOW ON SATURDAY LOOKS LIKE IT WILL BE JUST COLD
ENOUGH AND AROUND JUST LONG ENOUGH TO ALLOW FOR A MIX AND RAIN AND
SNOW. CONSIDERING THE LACK OF GOOD ICE CRYSTAL GROWTH AVAILABLE...AND
LACK OF STRONG LIFT...AND THE FACT THAT TEMPERATURES WILL ONLY BE
IDEAL FOR A SHORT PERIOD OF TIME...LITTLE IF ANY SNOWFALL
ACCUMULATION IS EXPECTED. THE PRECIP SHOULD BE OUT OF EASTERN
KENTUCKY BY LATE SATURDAY AFTERNOON.

TEMPERATURES DURING THE PERIOD LOOK TO BE BELOW NORMAL FOR DAY TIME
HIGHS DUE TO PERSISTENT CLOUD COVER AND COLD AIR ADVECTION ASSOCIATED
WITH NORTHERLY WINDS. IN GENERAL...DAY TIME HIGHS TODAY AND SATURDAY
SHOULD MAX OUT FROM THE UPPER 30S IN OUR NORTH TO THE LOWER 40S SOUTH
OF THE HAL ROGERS PARKWAY. TONIGHTS LOW SHOULD FALL TO AROUND FOR
MOST LOCATIONS...WITH THE WARMER READINGS SOUTH OF THE HAL
ROGERS...AND A FEW MID 20S READINGS POSSIBLE NORTH OF I-64.

.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 300 AM EST FRI DEC 19 2014

PROGRESSIVE PATTERN WILL CONTINUE THROUGH THE EXTENDED PORTION OF
THE FORECAST. FORTUNATELY...THE NEXT STORM SYSTEM SHOULD HOLD OFF
UNTIL LATE SUNDAY NIGHT INTO MONDAY MORNING...WITH A DRY END
EXPECTED TO THE WEEKEND. A SHORTWAVE TROUGH PUSHING NORTH ALONG THE
SPINE OF THE APPALACHIANS WILL BE RESPONSIBLE FOR THE UNSETTLED
WEATHER LATE SUNDAY NIGHT. STILL PLENTY OF UNCERTAINTY WITH HOW FAR
NORTHWEST PRECIPITATION WILL EXTEND AND WHAT SOUTHEAST DOWN SLOPING
WINDS WILL PLAY ON PRECIPITATION TRYING TO SPREAD INTO EASTERN
KENTUCKY. WE MAY FIND IT DIFFICULT TO SATURATE UP ENOUGH TO ALLOW
FOR MEASURABLE PRECIPITATION. THUS...WILL STAY IN THE CHANCE
CATEGORY FOR PRECIPITATION WITH THIS SYSTEM INTO MONDAY MORNING.
THIS SYSTEM WILL REMAIN ALL RAIN AS MILDER AIR SURGES NORTHWARD WITH
THIS SYSTEM. AS THIS WAVE DEPARTS...NOT MUCH FORCING TO SUPPORT MUCH
BY LATE IN THE DAY THROUGH MONDAY NIGHT. HOWEVER...A DEEP LOW
EXPECTED TO DEVELOP IN THE CENTRAL PLAINS AND TRACK INTO THE GREAT
LAKES INTO TUESDAY COULD CLIP OUR AREA WITH SOME WEAK FORCING FROM
TIME TO TIME. THUS...WILL MAINTAIN SOME VERY LOW POPS (AGAIN ALL
RAIN) THROUGH THIS TIME. ITS VERY POSSIBLE THE FIRST HALF OF THE
WEEK ENDS UP BEING FAIRLY DRY.

OUR NEXT STORM SYSTEM WILL ENTER THE PICTURE TUESDAY NIGHT AS A
SOUTHERN STREAM TROUGH PHASES WITH THE SYSTEM OVER THE GREAT LAKES.
THIS WILL SEND ANOTHER DEVELOPING LOW PRESSURE SYSTEM EAST ACROSS
THE REGION. MODELS ARE NOT IN GREAT AGREEMENT WITH THE EXACT TRACK
OF THIS SYSTEM...BUT AS IT STANDS NOW...MOST SOLUTIONS WOULD KEEP
PRECIPITATION MAINLY RAIN THROUGH TUESDAY NIGHT AS THE SYSTEM IS
REALLY LACKING THE COLD AIR. COLDER AIR WILL FINALLY START TO WRAP
INTO THE SYSTEM AS IT BEGINS TO DEPART...WITH RAIN MIXING WITH SNOW
THROUGH THE DAY WEDNESDAY...ESPECIALLY ON RIDGES. BY WEDNESDAY
NIGHT...ENOUGH BOUNDARY LAYER COOLING SHOULD TAKE PLACE TO ALLOW FOR
MORE SNOW THAN RAIN. HOWEVER...THE COLD AIR DEPICTED IS REALLY NOT
ALL THAT COLD AND THIS FAR OUT...WE MAY SEE MODELS TRY TO MODERATE
THIS COLD AIR A BIT OVER THE NEXT FEW DAYS. ALL IN ALL...NOT A VERY
IMPRESSIVE SNOW PRODUCING SYSTEM...BUT SOME LIGHT SNOW ACCUMULATIONS
COULD TAKE PLACE...ESPECIALLY IN UPSLOPE FLOW AREAS WEDNESDAY NIGHT
INTO CHRISTMAS MORNING. SNOW SHOWERS SHOULD BE WINDING DOWN ON
CHRISTMAS DAY AS RIDGING SPREADS EAST INTO THE REGION. WHILE ANOTHER
STORM SYSTEM COULD APPROACH BY LATE FRIDAY...LATEST ECMWF SOLUTION
IS ALREADY SHOWING SIGNS OF A SLOWER SYSTEM...SO IT LOOKS LIKE THIS
WOULD SHOULD HOLD OFF UNTIL SATURDAY OR SUNDAY. FOR WHAT ITS
WORTH...THIS ONE LOOKS LIKE IT MAY BE PRIMARILY RAIN YET AGAIN...BUT
THIS FAR OUT...THIS COULD CLEARLY CHANGE.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 125 PM EST FRI DEC 19 2014

LOW...MVFR...CLOUDS ARE LINGERING OVER THE NORTHEAST PORTION OF THE
AREA WITH JUST HIGH CLOUDS SEEN ELSEWHERE. EXPECT THE NORTHEAST
CLOUDS TO BREAK UP LATER THIS AFTERNOON AS THE HIGHER CLOUDS SLOWLY
START TO THICKEN AND DESCEND. THESE CLOUDS ARE COMING FROM WEAK LOW
PRESSURE WELL TO THE SOUTH OF THE AREA. THIS LOW WILL BRUSH BY
EASTERN KENTUCKY LATER TONIGHT AND INTO THE DAY SATURDAY. CANNOT RULE
OUT SOME LIGHT RAIN OR SNOW OVER OUR SOUTHERNMOST PARTS OF THE AREA
WITH MAYBE A SPRINKLE OR FLURRY FURTHER TO THE NORTH. IN THE SOUTH WE
COULD SEE SOME MVFR CIGS RETURN AS THE MAIN SYSTEM PASSES LATE
TONIGHT...OTHERWISE VFR CONDITIONS WILL DOMINATE. WINDS WILL REMAIN
LIGHT AND VARIABLE.

&&

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

$$

UPDATE...GREIF
SHORT TERM...AR
LONG TERM...KAS
AVIATION...GREIF




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