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 290401
AFDJKL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
1101 PM EST SUN DEC 28 2014

.UPDATE...
ISSUED AT 1100 PM EST SUN DEC 28 2014

RAIN IS TAPERING OFF SLIGHTLY FASTER THAN WAS NOTED IN THE PREVIOUS
UPDATE. TRIMMED BACK POPS AND HAVE THEM MOVING SE AT A FASTER RATE
NOW TO BETTER COORDINATE WITH THE CURRENT RADAR TRENDS. EVEN
STILL...WON/T BE SURPRISED IF THE POPS END UP MOVING OUT EVEN FASTER
THAN THE CURRENT FORECAST. THE CURRENT HRRR MODEL WOULD SUGGEST
CONTINUED SE MOVEMENT OF THE RAIN MOVING OUT OF MUCH OF THE CWA
BY 7Z...BUT BECOMING STALLED OUT ACROSS THE HIGHER TERRAIN FROM 7Z
THROUGH TOMORROW MORNING. THE MODEL HAS INITIALIZED WELL...BUT THIS
WILL BE SOMETHING TO WATCH.

UPDATE ISSUED AT 647 PM EST SUN DEC 28 2014

TWO MAIN CHANGES TO THE FORECAST. FIRST WAS TO CHANGE THE POPS OVER
THE NEXT FEW HOURS TO CENTER THE HIGHEST AMOUNTS OVER THE MORE
CENTRAL PORTION OF THE CWA...SLOWLY SHIFTING MORE EASTWARD INTO THE
HIGHEST TERRAIN OVER THE NEXT SEVERAL HOURS...THEN LINGERING SLIGHTLY
LONGER ACROSS THE SW CWA THAN WAS PREVIOUSLY FORECAST. THIS BETTER
ACCOUNTED FOR ONGOING CONDITIONS...AS WELL AS WHAT BOTH THE HI RES
AND SHORT TERM MODELS WERE FORECASTING. THE SECOND CHANGE WAS TO ADD
FOG WORDING TO THE CWA THROUGH THE OVERNIGHT HOURS. MUCH OF KY IS
REPORTING FOG...IN AREAS WITH AND WITHOUT RAIN. EXPECT THIS FOG TO
CONTINUE AS WE HEAD INTO THE OVERNIGHT HOURS WITH LOW LEVEL MOISTURE
FROM RAIN EXPECTED TO CONTINUE. THIS FOG SHOULD THEN BURN OFF DURING
THE MORNING HOURS AS DRIER AIR MOVES IN AND RAIN MOVES OUT. VALLEYS
WILL BE THE LAST TO CLEAR OUT. UPDATED THE NEAR TERM GRIDS WITH THE
LATEST OBSERVATIONAL DATA FOR TEMPS...DEW POINTS...AND WINDS TO MAKE
SURE THE CURRENT CONDITIONS WERE REFLECTED IN THE FORECAST.

&&

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 359 PM EST SUN DEC 28 2014

CURRENT CONDITIONS ACROSS THE AREA FEATURES RAIN CONTINUING TO MOVE
INTO THE AREA FROM THE SOUTHWEST. THE COLD FRONT HAS NOW PUSHED EAST
OF EASTERN KENTUCKY WITH NORTHWESTERLY FLOW NOW INTO THE AREA.
FREEZING TEMPERATURES LOOK TO BE NORTH AND WEST OF THE FORECAST AREA
AND SNOW IS NOT EXPECTED AT THIS TIME AS THE COLDER AIR IS A BIT TO
SLOW TO ADVECT INTO THE AREA BEFORE THE BULK OF THE MOISTURE EXITS TO THE
EAST TONIGHT. MEANWHILE...SURFACE LOW PRESSURE HAS DEVELOPED AND WILL
MOVE NORTHEAST THROUGH EASTERN TN TONIGHT. THIS WILL KEEP PRECIP
THROUGH FAR EASTERN KENTUCKY THROUGH THE NIGHT AS ANOTHER SURGE OF
MOISTURE WILL MOVE NORTHEAST. WITH THE MOIST LOW LEVELS...THOUGH
THERE WILL BE SOME CLOUD COVER...DO EXPECT SOME PATCHY FOG DEVELOPING
TONIGHT AND HAS ALREADY BEEN THE CASE IN SOME OF THE BLUEGRASS AREAS.
ESPECIALLY PLACES THAT REMAIN SATURATED THROUGH THE NIGHT.

CLOUD COVER AND PRECIP WILL SLOWLY MOVE OFF TO THE EAST FOR MONDAY
WITH SOME RAIN FALL SKIRTING ALONG THE FAR EASTERN COUNTIES AS THE
LOW EXITS OF TO THE EAST. HEADING INTO MONDAY NIGHT...THE COLDER AIR
WILL FILTER INTO THE AREA AND SOME LINGERING RAIN IN THE EAST MAY
CHANGE OR MIX TO SNOW IN THE HIGHER ELEVATIONS TOWARDS TUESDAY
MORNING. PARTIAL CLEARING IN THE NORTHWESTERN COUNTIES WILL RESULT IN
TEMPERATURES DROPPING INTO THE MID 20S FOR LOWS.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 359 PM EST SUN DEC 28 2014

THE EXTENDED PORTION OF THE FORECAST WILL BE BROKEN UP INTO THREE
SEGMENTS. PART ONE...ISOLATED RAIN AND SNOW SHOWERS ARE FORECAST TO
LINGER IN THE NORTHERLY MEAGERLY MOIST FLOW BEHIND A DEPARTING COLD
FRONT AND UPPER LEVEL LOW PRESSURE SYSTEM. THE SECOND PERIOD WILL
FEATURE AN EAST TO WEST ELONGATED RIDGE OF HIGH PRESSURE THAT IS
EXPECTED TO DROP SOUTHWARD OUT OF THE GREAT LAKES REGION TUESDAY
THROUGH THURSDAY. PART THREE WILL FEATURE A WELL DEVELOPED AND VERY
MOISTURE LADEN WEATHER SYSTEM THAT WILL AFFECT THE REGION FROM
THURSDAY NIGHT THROUGH SUNDAY. THE WEATHER SYSTEM THAT WILL BE
LEAVING THE AREA ON TUESDAY SHOULD BRING NOTHING MORE THAN LIGHT
RAIN AND SNOW WITH LITTLE OR NO SNOW ACCUMULATION. TEMPERATURES TO
BEGIN THE PERIOD LOOK TO BE BELOW NORMAL...WITH HIGHS IN THE 40S
DURING THE DAY...AND LOWS TUESDAY NIGHT IN THE LOW TO MID 20S. AN
ARCTIC AIR MASS IS THEN PROGGED TO SETTLE OVER THE REGION MID WEEK.
HIGHS ON WEDNESDAY AND THURSDAY WILL LIKELY NOT MAKE IT OUT OF THE
30S. OVERNIGHT LOWS WEDNESDAY AND THURSDAY NIGHT WILL BE EVEN
CHILLIER...WITH THE MERCURY BOTTOMING OUT AROUND 20 WEDNESDAY
NIGHT...AND THE MID TO UPPER 20S THURSDAY NIGHT.

THE BIG STORY IN THE EXTENDED WILL BE THE WEATHER SYSTEM THAT IS
FORECAST TO SOAK THE AREA TOWARD THE END OF THE WEEK. THERE IS NO
QUESTION THAT A POTENT WEATHER SYSTEM WITH EXTENSIVE PRECIPITATION
WILL AFFECT THE STATE OF KENTUCKY FRIDAY AND SATURDAY. THE QUESTIONS
WITH THIS SYSTEM WILL BE HOW QUICKLY WILL PRECIPITATION MOVE INTO
THE AREA AND HOW MUCH OF THE PRECIP WILL BE IN THE FORM OF SNOW?
RIGHT NOW THE GFS IS MUCH SLOWER AND WARMER THAN THE ECMWF WITH THE
END OF WEEK WEATHER PATTERN. THE GFS HAS ITS LOW MOVING FURTHER
NORTH THAN THE ECMWF. THAT BEING SAID...WITH SO MUCH UNCERTAINTY
INVOLVED...DECIDED TO GO WITH A COMPROMISE BETWEEN THE TWO
MODELS...SLIGHTLY FAVORING THE COLDER ECMWF MODEL. THIS IS BASED ON
THE FACT THAT THE MODELS HAVE BEEN RUNNING A BIT TOO WARM LATELY
WITH REGARDS TO LOW AND MIDDLE LEVEL TEMPERATURES. AFTER A PERIOD OF
MIXED PRECIP THURSDAY EVENING...AN AREA OF LIGHT SNOW IS BEING
FORECAST TO DEVELOP LATE THURSDAY NIGHT THROUGH EARLY FRIDAY
MORNING. THERE COULD BE SOME LIGHT ACCUMULATIONS WITH THIS BAND OF
SNOW AS IT MOVES NORTH...BUT IT WILL LIKELY NOT STAY ON THE GROUND
LONG AS TEMPERATURES RISE INTO THE 40S ON FRIDAY. AN EXTENDED PERIOD
OF GOOD SOAKING RAIN IS EXPECTED FRIDAY THROUGH SATURDAY...WITH THE
POTENTIAL FOR SOME SNOW ALONG AND NORTH OF I-64 FRIDAY NIGHT AND
SATURDAY NIGHT...AS SOME NEAR FREEZING AIR COULD SPILL INTO THAT
AREA EACH NIGHT. AS IS COMMON IN WINTER...THE MODELS WILL NEED TO BE
WATCHED VERY CLOSELY TO SEE WHICH DIRECTION THINGS TREND...MORE RAIN
OR MORE SNOW WILL BE THE QUESTION AS WE MOVE FORWARD.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 701 PM EST SUN DEC 28 2014

A COLD FRONT HAS MOVED SE OF KY...THOUGH RAIN WILL LIKELY LINGER
THROUGHOUT MUCH OF THE NIGHT AT THE TAF SITES. DESPITE SURFACE WINDS
SWITCHING TO A MORE NRLY DIRECTION BEHIND THIS FRONT...THE MID AND
UPPER LEVELS STILL POSSESS A STRONG SWRLY COMPONENT...ALLOWING THIS
MOISTURE TO CONTINUE TO FILTER INTO THE REGION. FOG IS BEING OBSERVED
NOW ACROSS MUCH OF KENTUCKY...AND WITH MOISTURE EXPECTED TO CONTINUE
OVERNIGHT...THE FOG WILL LIKELY LINGER INTO THE MORNING HOURS. WHILE
CIGS WILL REMAIN NEAR OR AT AIRPORT MINIMUMS...THE FOG AND RAIN WILL
LIKELY KEEP VIS FLUCTUATING BETWEEN LIFR AND BELOW AIRPORT MINS.
GIVEN THE UNCERTAINTY AND LIKELY VARIABILITY IN THIS WEATHER
PATTERN...WENT WITH A GENERAL AND OPTIMISTIC 1SM AT THE TAF SITES
DURING THE OVERNIGHT HOURS. FOG WILL BURN OFF AND VIS WILL SLOWLY
IMPROVE TOMORROW MORNING. ANOTHER WEAKER BOUNDARY IS EXPECTED TO MOVE
THROUGH THE REGION DURING THE AFTERNOON FROM THE NW...SO CIGS WILL
LIKELY REMAIN MVFR.


&&

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

$$

UPDATE...JMW
SHORT TERM...SHALLENBERGER
LONG TERM...AR
AVIATION...JMW






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