000
FXUS63 KJKL 140306 AAB
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON KY
1106 PM EDT THU MAR 13 2014

.UPDATE...
ISSUED AT 1100 PM EDT THU MAR 13 2014

HOURLY TEMPERATURES AND DEWPOINTS HAVE BEEN FRESHENED UP BASED ON
RECENT OBSERVATIONS. NO SIGNIFICANT CHANGES ARE NEEDED AT THIS TIME.

UPDATE ISSUED AT 835 PM EDT THU MAR 13 2014

A BAND OF MID LEVEL CLOUDS IS MOVING EAST SOUTHEAST ACROSS THE OHIO
VALLEY REGION ASSOCIATED WITH ISENTROPIC LIFT AS THE AIRMASS IS
ALREADY STARTING TO MODERATE ALOFT. HOWEVER...DEWPOINTS REMAIN IN THE
SINGLE DIGITS TO AROUND 10 ON THE RIDGETOPS AND MORE OPEN AREAS AND
AREA GENERALLY IN THE TEENS IN THE VALLEYS. THE BAND OF MID LEVEL
CLOUDS SHOULD WORK ACROSS THE NORTH AND EAST PART OF THE REGION OVER
THE NEXT 3 TO 5 HOURS AND DISRUPT RADIATIONAL COOLING TO SOME DEGREE.
HOWEVER...OTHER THAN THAT CLOUDS SHOULD BE CLEAR OVERNIGHT WITH THE
PRESSURE GRADIENT GRADUALLY INCREASING. KY MESONET SITES INDICATE
THAT VALLEYS ARE STARTING TO DECOUPLE AND ALTHOUGH THE BAND OF MID
CLOUDS AND SOME MIXINESS LATE SHOULD KEEP TEMPS FROM QUITE REACHING
CURRENT DEWPOINTS IN THE VALLEYS...HAVE OPTED TO INSERT A
RIDGE/VALLEY TEMP SPLIT IN THE GRIDS AND ZFP. SEVERAL VALLEY
LOCATIONS WERE ALREADY NEARING THEIR FORECAST LOWS.

AT THIS POINT...18Z MODEL DATA STILL SUGGESTS THAT CRITICAL FIRE
WEATHER VALUES COULD BE MET ON FRI AFTERNOON AND AT THIS TIME...
PLAN TO LET THE FIRE WEATHER WATCH ROLL. CONFIDENCE IS NOT HIGH
ENOUGH FOR A WARNING AT THIS POINT.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 325 PM EDT THU MAR 13 2014

18Z SFC ANALYSIS SHOWS HIGH PRESSURE NOW IN CONTROL OF THE WEATHER
OVER KENTUCKY ERODING THE CLOUDS AND MAKING FOR A SUNNY AFTERNOON.
THIS SUN HAS DONE A NUMBER ON THE PLACES THAT SAW MEASURABLE
ACCUMULATION LAST NIGHT WITH MUCH OF IT NOW GONE AS EVIDENCED BY
THE LATEST VISIBLE SATELLITE IMAGES. TEMPERATURES ARE STRUGGLING TO
RISE TOO FAR INTO THE 30S FOR MOST PLACES...BUT LOW 40S ARE NOT OUT
OF THE QUESTION OVER THE FAR SOUTH. DEWPOINTS HAVE BEEN BOUNCING
AROUND THIS AFTERNOON...WITH READINGS IN THE SINGLE DIGITS FOR MANY
PLACES AND IN THE 10 TO 15 DEGREE RANGE ACROSS THE NORTHEAST. WINDS
HAVE BEEN LIGHT FOR MUCH OF THE DAY...BUT LATELY THEY HAVE PICKED UP
FROM THE WEST GUSTING TO NEAR 15 MPH ON THE RIDGES.

THE MODELS ARE IN GOOD AGREEMENT ALOFT AS THE PATTERN FLATTENS OUT
FOLLOWING THE EXIT OF THE TROUGH TO THE EAST. THE NORTHERN STREAM
WILL BRING A SHALLOW TROUGH TOWARD THE AREA ON FRIDAY WITH SOME WEAK
ENERGY SWINGING THROUGH THE OHIO VALLEY INTO SATURDAY MORNING. THE
CORE OF THIS RATHER SUBTLE FEATURE STAYS WELL NORTH OF THE AREA.
GIVEN THIS MODEL AGREEMENT HAVE LEANED TOWARD THE DETAILS FROM THE
NAM12.

SENSIBLE WEATHER WILL FEATURE ANOTHER COLD NIGHT WITH DECENT
RADIATIONAL COOLING...TEMPERED BY SOME MID LEVEL CLOUDS IN THE NORTH
LATE IN THE NIGHT. THIS WILL LEAD TO A RIDGE TO VALLEY TEMPERATURE
SPLIT SETTING UP BY MID EVENING AND CONTINUING THROUGH THE NIGHT.
HAVE ADJUSTED THE HOURLY CURVE AND VARIOUS EDIT AREAS TO REFLECT THIS
DIFFERENCE. FOR FRIDAY...A TIGHTENING PRESSURE GRADIENT BETWEEN THE
LARGE LOW PASSING BY TO THE NORTH AND HIGH PRESSURE TO THE SOUTH WILL
RESULT IN BREEZY CONDITIONS AND GUSTY WINDS BY MIDDAY...THOUGH SOME
MID AND HIGH CLOUDS MAY LIMIT THE MOMENTUM TRANSFER DURING THE
AFTERNOON. IN ADDITION TO THESE WINDS...RELATIVE HUMIDITIES WILL BE
BOTTOMING OUT IN THE 25 TO 30 PERCENT RANGE DURING THE EARLY
AFTERNOON LEADING TO FIRE WEATHER CONCERNS. WILL LIKELY ISSUE A FIRE
WEATHER WATCH TO HIGHLIGHT THE FIRE WX THREAT AND HIT THE WINDS HARD
IN THE HWO. THE LOW PASSING TO THE NORTH WILL BRING A...PROBABLY
DRY...COLD FRONT THROUGH EAST KENTUCKY LATER THAT NIGHT. THIS WILL
ALSO MEAN MOSTLY CLOUDY SKIES AND MORE UNIFORM TEMPERATURES THAN
TONIGHT.

USED AN ADJUSTED VERSION OF THE CONSSHORT FOR TEMPS DURING THE NEXT
24 HOURS AND THEN FAVORED THE NAM12 DIURNAL CURVE WITH EDIT AREAS AND
POINT TWEAKED CONSALL MAX AND MIN T GRIDS AS THE STARTING POINT FOR
THE HOURLY TEMPS THROUGH SATURDAY MORNING. ALSO...USED THE
BCCONSSHORT FOR TD AND WINDS WITH THE BCCONSALL AFTER THE FIRST 24
HOURS. THESE WERE MASSAGED FOR THE CURRENT CONDITIONS AND TRENDS AS
WELL AS RAMPED UP A BIT HIGHER FROM MIDDAY INTO FRIDAY AFTERNOON...
ALONG WITH INCREASED GUSTS FOR A TIME. AS FOR POPS...ENDED UP
CLOSER TO THE DRIER MAV NUMBERS THROUGH SATURDAY MORNING.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 349 PM EDT THU MAR 13 2014

BETTER AGREEMENT BETWEEN THE LONG RANGE MODELS THIS TIME AROUND. BOTH
THE GFS AND ECMWF WERE IN GOOD AGREEMENT WITH THE TIMING OF THE
OVERALL LARGE SCALE SYNOPTIC WEATHER PATTERN ACROSS THE CENTRAL AND
EASTERN CONUS. THE CONSENSUS AT THIS TIME IS FOR A LARGE AREA OF LOW
PRESSURE TO MOVE ACROSS NORTHERN NEW ENGLAND AND UP THE EASTERN
CANADIAN COAST SATURDAY AND SUNDAY. IN THE MEANTIME...TWO OTHER AREAS
OF LOW PRESSURE ARE PROGGED TO DEVELOP ACROSS THE NORTHERN PLAINS AND
SOUTHERN PLAINS LATE SATURDAY. AS THESE SYSTEMS MOVE EASTWARD...THE
ARE EXPECTED TO PHASE TOGETHER...WITH A MUCH STRONG AND BROADER AREA
OF LOW PRESSURE FORMING ACROSS THE SOUTHERN MISSISSIPPI WESTERN
TENNESSEE VALLEY REGION SUNDAY AFTERNOON. THIS LARGER PHASED SYSTEM
WILL BE OUR WEATHER MAKER TO END THE WEEKEND AND BEGIN THE NEW WORK
WEEK. BASED ON THE LATEST DATA...THE FIRST DROPS OF RAIN MAY MOVE
INTO THE AREA BETWEEN 15 AND 18Z ON SUNDAY. FAIRLY BRISK WINDS OF 10
TO 15MPH WOULD BE LIKELY WITH THIS WEATHER SYSTEM...AS THE MODELS
HAVE A DECENT PRESSURE GRADIENT ASSOCIATED WITH IT. PRECIPITATION
WILL BE MOSTLY IN THE FORM OF RAIN IN THE WARMER AIR EAST OF THE LOW
PRESSURE AS IT MIGRATES TO THE EAST. AS COLDER AIR FILTERS IN ON THE
WESTERN AND NORTHWESTERN PORTIONS OF THE SYSTEM SUNDAY NIGHT INTO
MONDAY MORNING...THE PRECIPITATION WILL LIKELY CHANGE FROM RAIN TO A
RAIN SNOW MIX AND EVENTUALLY ALL SNOW FOR A SHORT PERIOD OF TIME.
LITTLE IF ANY SNOW ACCUMULATION IS EXPECTED AT THIS TIME DUE TO THE
PROGRESSIVE NATURE OF THE PARENT LOW AND WARM GROUND TEMPERATURES.

TEMPERATURES THROUGHOUT THE PERIOD WILL BE MOSTLY AT OR ABOVE
NORMAL...WITH HIGHS IN THE MID TO UPPER 50S. TEMPERATURES ON SUNDAY
AND NMONDAY...HOEVER...WILL BE QUITE A BIT COOLER DUE TO THE
INFLUENCE OF THE LOW PRESSURE SYSTEM MENTIONED EARLIER. HIGHS ON EACH
DAY ARE EXPECTED TO REMAIN IN THE 40S...DUE TO THE INFLUENCE OF
CLOUDS AND PRECIPITATION...AND AS WINDS SHIFT TO THE NORTH AND
NORTHWEST. TOWARD THE END OF THE WEEK THINGS GET A BIT MURKIER...AS
THE MODELS HAVE VERY DIFFERENT SOLUTIONS FROM WEDNESDAY THROUGH
THURSDAY NIGHT. THIS PERIOD COULD SEE SOME MORE PRECIPITATION FROM A
FAST MOVING AREA OF LOW PRESSURE THAT WOULD FOR OVER THE NORTHERN
PLAINS AND DRAG A COLD FRONT ACROSS THE OHIO AND TENNESSEE VALLEYS.
THE ISSUES HERE ARE MANY INCLUDING THE TIMING AND EXACT TRACK OF LOW
PRESSURE AND THE TEMPERATURE REGIME ASSOCIATED WITH IT. FOR
NOW...DECIDED TO GO WITH THE LATEST RUN OF THE ECMWF MODEL FOR THE
FORECAST FOR NEXT WEDNESDAY AND THURSDAY...WITH A QUICK HIT OF LIGHT
RAIN WEDNESDAY THROUGH THURSDAY...AS LOW PRESSURE MOVES QUICKLY
ACROSS THE AREA.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 835 PM EDT THU MAR 13 2014

VFR IS EXPECTED FOR THE ENTIRE PERIOD AS HIGH PRESSURE SHIFTS FROM
THE TN VALLEY AND APPALACHIANS TO THE CAROLINAS. WINDS WILL BE LIGHT
AND VARIABLE TONIGHT AND THROUGH ABOUT 13 TO 16Z...BEFORE PICKING UP
FROM THE SOUTHWEST AT 10 TO 20 KT WITH GUSTS POSSIBLY AS HIGH AS 30KT
IN ADVANCE OF A COLD FRONT DURING THE 16Z AND 23Z PERIOD.


&&

.JKL WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM 11 AM EDT FRIDAY THROUGH FRIDAY EVENING
FOR KYZ044-050>052-058>060-068-069-079-080-083>088-104-106>120.

&&

$$

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