674
FXUS63 KJKL 122358
AFDJKL
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
658 PM EST TUE NOV 12 2024
KEY MESSAGES
- AN APPROACHING COLD FRONT WILL INCREASE CHANCES FOR RAIN FROM
WED NIGHT TO THU EVENING.
- TEMPERATURES WILL BE NEAR NORMAL THROUGH FRI, WITH THE EXCEPTION
OF A SLIGHT UPTICK TO 5 TO 10 DEGREES ABOVE NORMAL ON WED.
UPDATE
ISSUED AT 658 PM EST TUE NOV 12 2024
FORECAST REMAINS LARGELY UNCHANGED OVERNIGHT OTHER THAN A SLIGHT
DOWNWARD ADJUSTMENT IN THE EXPECTED SKY COVER.
SHORT TERM
(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 358 PM EST TUE NOV 12 2024
LATE THIS AFTERNOON, AN UPPER LEVEL RIDGE WAS CENTERED IN THE
EASTERN GULF OF MEXICO TO THE BAHAMAS WITH THE AXIS OF THIS RIDGE
EXTENDING INTO THE MID MS AND LOWER OH VALLEYS TO THE WESTERN
GREAT LAKES. FURTHER WEST, A SHORTWAVE TROUGH EXTENDED FROM
ALBERTA AND SASKATCHEWAN SOUTH TO THE FOUR CORNERS VICINITY TO
NORTHERN MEXICO WITH ANOTHER TROUGH UPSTREAM OF THAT OVER THE
EASTERN PACIFIC. AT THE SURFACE, A RIDGE OF HIGH PRESSURE WAS
CENTERED NEAR THE ONTARIO AND QUEBEC BORDER AND EXTENDED SOUTH
ACROSS THE GREAT LAKES TO THE OH AND TN VALLEY REGIONS AND
EASTERN KY. FURTHER WEST, AN AREA OF LOW PRESSURE WAS CENTERED IN
THE SD VICINITY WITH A COLD FRONT SOUTH ACROSS THE HIGH PLAINS TO
NM.
THIS EVENING TO WEDNESDAY, THE AXIS OF THE UPPER LEVEL RIDGE WILL
SHIFT EAST, REACHING THE SOUTHEASTERN STATES TO THE SOUTHERN
APPALACHIANS TO THE EASTERN GREAT LAKES TO SOUTHERN ONTARIO TO
WESTERN QUEBEC BY DAWN ON WEDNESDAY. THE AXIS OF THE RIDGE WILL
MOVE EAST OF THE FL PENINSULA TO THE CAROLINAS TO LAKE ONTARIO AND
QUEBEC LINE ON WEDNESDAY EVENING AS THE QUICK MOVING TROUGH AXIS
SHIFTS EAST. A PRECEDING LEAD SHORTWAVE IS PROGGED TO MOVE INTO
THE LOWER OH AND TN VALLEYS ON WEDNESDAY AND CROSS EASTERN KY ON
WEDNESDAY EVENING WHILE THE MAIN UPPER LEVEL TROUGH AXIS
AND ASSOCIATED UPPER LEVEL LOW SHOULD MOVE EAST OF THE MS RIVER
BEFORE THE END OF THE PERIOD. MEANWHILE, SFC HIGH PRESSURE WILL
SHIFT EAST OF THE AREA THIS EVENING AND TONIGHT WHILE
SOUTHEASTERLY TO SOUTHERLY GRADIENT WILL LEAD TO A RIDGE/VALLEY
TEMPERATURE SPLIT. THE SFC RIDGE AND UPPER LEVEL RIDGE SHOULD
BOTH MOVE FURTHER EAST OF THE AREA ON WEDNESDAY WHILE THE SFC LOW
TRACKS ACROSS THE PLAINS TO THE MID MS/MO VALLEY AREA AND THE
TRAILING COLD FRONT NEARS THE MID MS TO EASTERN TX AREA. A
DEVELOPING WARM FRONT SHOULD ALSO LIFT ACROSS MUCH OF THE AREA IN
ASSOCIATION WITH THE LEAD SHORTWAVE. PW IS PROGGED PER THE HREF
TO CLIMB FROM 0.2 TO 0.3 INCHES THIS EVENING TO 0.3 TO 0.5 INCHES
ON WEDNESDAY MORNING AND BY THE EARLY EVENING TO 0.3 INCHES NEAR
THE WV BORDER AND IN AREAS OF FAR EASTERN KY TO NEAR 1.2 INCHES
NEAR LAKE CUMBERLAND.
WEDNESDAY NIGHT, THE LEAD SHORTWAVE TROUGH WILL CROSS THE AREA ON
WEDNESDAY EVENING WITH THE UPPER LEVEL LOW AND ASSOCIATED UPPER
LEVEL TROUGH WORKING EAST OF THE MS RIVER. THE WARM FRONT SHOULD
LIFT NORTH OF THE AREA ON WEDNESDAY EVENING WHILE THE SFC LOW IS
PROGGED TO TRACK TO NEAR CHICAGO/SOUTH END OF LAKE MI LATE WHILE
THE TRAILING COLD FRONT MOVES INTO WESTERN KY TO THE MOUTH OF THE
MS VICINITY. MOISTURE TRANSPORT AHEAD OF THE FRONT AND THE MID
LEVEL WAVE PW SHOULD CLIMB FURTHER TO 1.1 TO 1.3 IN ADVANCE OF THE
FRONT ON WEDNESDAY NIGHT WITH GOOD OMEGA ANTICIPATED WITH SOME
JET DYNAMICS AND MID LEVEL FORCING ASSOCIATED WITH THE TROUGH
LEADING TO GOOD OMEGA WITHIN THE COLUMN. DRIER AIR WILL BEGIN TO
ARRIVE LATE, WITH 1.1 TO 1.2 INCH PW IN THE FAR EAST AND 0.7 TO
0.9 INCH RANGE IN THE WEST NEAR DAWN ON THURSDAY.
THIS SYSTEM WILL RESULT IN A GOOD CHANCE OF RAIN AREAWIDE AND WITH
THE EXPECTED FORCING, A WIDESPREAD WETTING RAIN IS EXPECTED WITH
12Z HREF PROBABILITIES OF ABOUT 40 TO NEAR 100 PERCENT FOR A HALF
OF AN INCH OF RAIN OR MORE AND 85 TO NEAR 100 PERCENT PROBABILITY
OF 0.25 INCHES OR MORE AREAWIDE BY DAWN ON THURSDAY.
FOLLOWING A MODERATE RIDGE/VALLEY TEMPERATURE SPLIT TONIGHT,
TEMPERATURES WILL MODERATE TO SEVERAL DEGREES ABOVE NORMAL ON
WEDNESDAY AHEAD OF THE BOUNDARY WITH SOUTHEASTERLY DOWNSLOPE FLOW
INTO THE REGION, ESPECIALLY THE EAST. WITH THIS IN MIND, OPTED TO
GO WITH HIGHS A COUPLE OF DEGREES ABOVE NBM DETERMINISTIC IN THAT
AREA ALONG WITH DRIER DEWPOINTS HEDGING TOWARD THE LOWER NBM
PERCENTILES AS WELL. FOR THE PAST SEVERAL DAYS, HIGHS HAVE BEEN
RUNNING A BIT HIGHER THAN NBM DETERMINISTIC FOR SEVERAL
LOCATIONS.
LONG TERM
(THURSDAY THROUGH TUESDAY)
ISSUED AT 405 PM EST TUE NOV 12 2024
THE LONG TERM FORECAST IS CHARACTERIZED BY AN AMPLIFIED WEATHER
PATTERN AND ACTIVE SENSIBLE WEATHER HERE IN EASTERN KENTUCKY AS A
RESULT. AT THE BEGINNING OF THE FORECAST PERIOD, A NEGATIVELY-TILTED
UPPER LEVEL TROUGH WILL BE EJECTING ACROSS THE OHIO RIVER VALLEY,
WITH A SURFACE LOW PRESSURE CYCLONE CENTERED IN THE VICINITY OF LAKE
MICHIGAN AND ITS TRAILING COLD FRONT SWEEPING EAST INTO OUR FORECAST
AREA. RAIN SHOWERS AND OVERCAST SKIES WILL PERSIST FROM WEDNESDAY
INTO THURSDAY, BUT THE WARM TEMPERATURES WILL BE LEFT BEHIND.
THURSDAY HIGH TEMPERATURES WILL BE RELEGATED TO NEARLY 10 DEGREES
BELOW WEDNESDAY'S BY THE CLOUDS AND BY EVAPORATIVE COOLING
PROCESSES. BOTH THE COOLING TREND AND THE GREY SKIES WILL CARRY OVER
INTO FRIDAY, WITH HIGHS IN THE POST-FRONTAL AIRMASS HOVERING AROUND
THE MID TO UPPER 50S. RAIN CHANCES WILL LINGER AROUND THE
NORTHEASTERN THIRD OF THE FORECAST AREA ON FRIDAY AMIDST RESIDUAL
MOISTURE AND MODEST UPPER LEVEL DYNAMIC SUPPORT. HOWEVER, DRIER AIR
WILL WRAP AROUND THE BACKSIDE OF THIS TROUGH AND FOSTER CLEARING
FROM THE SOUTHWEST TO THE NORTHEAST OVERNIGHT INTO SATURDAY. MOIST
GROUNDS AND DECREASING CLOUD COVERAGE COULD YIELD IN FOG ON FRIDAY
NIGHT, ESPECIALLY IN THE CONVENTIONALLY FAVORED RIVER VALLEYS.
BY THIS WEEKEND, MID LEVEL RIDGING AND A SURFACE HIGH PRESSURE WILL
BUILD BACK INTO THE AREA. THE RESULTANT DRIER AIR, SHIFTING WINDS,
AND RISING UPPER LEVEL HEIGHTS WILL COLLECTIVELY ALLOW TEMPERATURES
TO WARM FROM AROUND 60 ON SATURDAY TO NEAR 65 ON SUNDAY. SKIES WILL
BE SUNNIER ON SATURDAY THAN ON SUNDAY, AND CONFIDENCE IN THE
CONVENTIONAL NOCTURNAL RIDGE-VALLEY TEMPERATURE SPLITS AND VALLEY
FOG IS THUS GREATEST ON SATURDAY NIGHT INTO SUNDAY. THE MOST
SHELTERED VALLEYS MAY DIP DOWN INTO THE MID 30S DURING THIS TIME
FRAME, ALTHOUGH RIDGES WILL BE MUCH WARMER WITH LOWS CLOSER TO 40
DEGREES.
CONFIDENCE IN THE ABOVE FORECAST IS GREATER THAN USUAL. THERE IS
REMARKABLE AGREEMENT IN THE AVAILABLE DETERMINISTIC MODEL GUIDANCE
ON THE POSITIONING AND TIMING OF THE PARENT SYNOPTIC WEATHER
FEATURES THROUGH THE END OF THIS WEEK. IN A SIMILAR MANNER, MODELED
LREF SPREAD FOR VARIABLES SUCH AS TEMPERATURES AND PRECIPITABLE
WATER CONTENT IS FAIRLY LOW THROUGH SUNDAY AFTERNOON. BEYOND THIS
TIME FRAME, TOWARDS THE END OF THE LONG TERM FORECAST PERIOD, THE
ABOVE STATEMENTS ARE NOT TRUE. THERE IS REMARKABLY GREATER MODEL
SPREAD IN THE FORECAST GUIDANCE FOR NEXT WEEK, BUT A SIGNAL FOR MORE
ACTIVE WEATHER EXISTS IN THE ENSEMBLES. A SERIES OF TROUGH EJECTIONS
OFF VARIOUS PORTIONS OF THE ROCKY MOUNTAINS WILL RE-AMPLIFY THE
PATTERN ALOFT AND REINTRODUCE UPPER LEVEL SUPPORT FOR CLOUDS AND
PRECIPITATION INTO THE FORECAST HERE IN EASTERN KENTUCKY. HOWEVER,
QUESTIONS LINGER REGARDING THE MAGNITUDE OF GULF MOISTURE RETURN AND
THE DEGREE TO WHICH TEMPERATURES RECOVER BY MONDAY. FOR EXAMPLE,
LREF MEMBER AND NBM PERCENTILE SPREADS FOR TEMPERATURES ARE BETWEEN
10 AND 15 DEGREES EARLY NEXT WEEK. THIS INDICATES THAT THERE ARE
LOWER LEVELS OF FORECAST CONFIDENCE EARLY NEXT WEEK AND THAT RUN-TO-
RUN DETERMINISTIC MODEL SWINGS ARE POSSIBLE. THE FORECAST FOR NEXT
MONDAY AND TUESDAY THUS RELIES HEAVILY ON THE NBM, WHICH RESOLVES
MOSTLY CLOUDY SKIES, SLIGHT TO CHANCE POPS, AND TEMPERATURES IN THE
60S/40S.
AVIATION
(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 633 PM EST TUE NOV 12 2024
VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES THROUGH THE AVIATION
FORECAST PERIOD AS A RIDGE OF HIGH PRESSURE SHIFTS EAST. FOG IS
EXPECTED TO DEVELOP IN THE RIVER VALLEYS BETWEEN ABOUT 04Z AND
13Z WITH SOME REDUCTIONS TO MVFR OR IFR, THOUGH TAF SITES WILL
NOT BE AFFECTED. WINDS SHOULD BE LIGHT AND VARIABLE TONIGHT AND
WEDNESDAY MORNING BEFORE AN UPTICK FROM THE SOUTHEAST AT 5 TO
10KTS OCCURS ON WEDNESDAY AFTERNOON.
JKL WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...GEERTSON
SHORT TERM...JP
LONG TERM...MARCUS
AVIATION...GEERTSON/JP
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