167
FXUS63 KJKL 070328 AAA
AFDJKL
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON KY
1128 PM EDT TUE JUN 6 2023
UPDATE
ISSUED AT 1128 PM EDT TUE JUN 6 2023
THE LEADING EDGE OF THE PRECIPITATION SHIELD ASSOCIATED WITH THE
APPROACHING COLD FRONT HAS MOVED IN ACROSS THE I-64 CORRIDOR. HAVE
INCREASED POPS A BIT MORE ASSOCIATED WITH THIS INITIAL BAND ACROSS
OUR NORTH AND NORTHEAST FRINGES. LOOKING UPSTREAM ON MOSAIC
RADAR, THERE LOOKS TO BE A BREAK IN THE ACTION FOR A FEW HOURS,
BEFORE PRECIPITATION FILLS IN ONCE AGAIN DURING THE PRE-DAWN
HOURS, AS A BETTER SLUG OF MOISTURE MOVES IN FROM THE NORTHWEST.
HAVE ADJUSTED THE POPS TO ACCOUNT FOR THIS BREAK INTO THE
OVERNIGHT HOURS, BEFORE GENERALLY BLENDING BACK INTO THE EXISTING
FORECAST, WHICH ALREADY DEPICTS THE UPTICK NICELY CLOSER TOWARDS
DAWN. THE ONLY OTHER ADJUSTMENT OF NOTE WAS TO DELAY THE SLIGHT
CHANCE OF THUNDER, GIVEN THE VERY MODEST INSTABILITY SHOWN ON THE
SPC MESOANALYSIS, AND CONFIRMED WITH THE LACK LIGHTNING UPSTREAM.
UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 814 PM EDT TUE JUN 6 2023
THE FORECAST REMAINS ON TRACK. DID FRESHEN UP HOURLY TEMPERATURES,
ACCOUNTING FOR THE SHARPER VALLEY DROP AS SEEN ON LOCAL
OBSERVATIONS. UPDATES WILL BE OUT SHORTLY.
SHORT TERM
(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 450 PM EDT TUE JUN 6 2023
A MASSIVE, STACKED LOW PRESSURE SYSTEM IS SPINNING OVER THE
CANADIAN MARITIMES THIS AFTERNOON. OUR MID/UPPER LEVEL FLOW AROUND
THE SYSTEM TRACES BACK WELL INTO CANADA, AND IS SENDING ANOTHER
SURFACE COLD FRONT SOUTHWARD. THE FRONT WAS LAID OUT FROM NORTHERN
IL TO SOUTHERN OH THIS AFTERNOON. OUR CURRENT AIR MASS IS DRY BY
WARM SEASON STANDARDS, BUT THERE IS SOMEWHAT MORE HUMID AIR POOLED
OVER THE UPPER MIDWEST WHICH SHOULD BE ADVECTED TO THE SOUTHEAST
ALONG THE FRONT TONIGHT. AT THE SAME TIME, VIRGA FALLING FROM
MID LEVELS WILL ALSO HELP TO MOISTEN THE LOWER ATMOSPHERE. THE END
RESULT IS THAT MODELS ARE PERSISTENT IN DEVELOPING SHOWERS FROM
NORTH TO SOUTH OVER OUR AREA LATE TONIGHT AND WEDNESDAY MORNING.
FORECAST SOUNDINGS ALSO SHOW MARGINAL INSTABILITY. HAVE USED
FAIRLY HIGH POPS WITH A SMALL THUNDER POTENTIAL, WITH HIGHEST POPS
OVER OUR SOUTHERN COUNTIES WHERE MODELS BRINGS THINGS TO A PEAK.
MUCH COOLER AND DRIER AIR THEN ARRIVES BEHIND THE FRONT ON
WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT, WITH CLEARING SKIES.
UNUSUALLY COOL READINGS IN THE 40S TO LOWER 50S ARE FORECAST BY
DAWN ON THURSDAY.
LONG TERM
(THURSDAY THROUGH TUESDAY)
ISSUED AT 413 PM EDT TUE JUN 6 2023
KEY POINTS:
1. DRY AND UNSEASONABLY COOL ON THURSDAY AND THURSDAY NIGHT WITH
TEMPERATURES RUNNING ~ 8 TO 10 DEGREES BELOW SEASONAL AVERAGES.
2. A WARMING TREND FRIDAY THROUGH EARLY SUNDAY SENDS TEMPERATURES
BACK TO NEAR OR ABOVE AVERAGE LEVELS.
3. AN UNSEASONABLY DEEP UPPER LEVEL LOW AND AN ASSOCIATED COLD
FRONT BRINGS THE LIKELIHOOD FOR SHOWERS AND AND POSSIBLE
THUNDERSTORMS ON SUNDAY INTO MONDAY.
4. AT LEAST A WETTING RAINFALL (0.10 INCH) CAN BE EXPECTED FOR
NEARLY ALL, IF NOT ALL, OF THE FORECAST AREA DURING THE SUNDAY
INTO MONDAY TIMEFRAME.
ANALYSIS:
AN ATYPICALLY BLOCKY AND AMPLIFIED EARLY SUMMER WEATHER
PATTERN CONTINUES THROUGH THE LONG-TERM. THE 06/12Z MODEL SUITE
ANALYSIS SHOWS A SLOWLY FILLING ~547 DAM LOW NEAR/OVER THE UPPER
CONNECTICUT VALLEY AT THE START OF THE PERIOD THURSDAY MORNING.
FUTHER WEST, AN ~582 HIGH IS CENTERED OVER THE WESTERN DAKOTAS.
TWO AXES FORK POLEWARD FROM THE HIGH, ONE TOWARD NORTHERN
LABRADOR VIA THE SOUTHERN HUDSON BAY AND THE OTHER TOWARDS THE
CHUKCHI SEA (ARCTIC OCEAN NORTHWEST OF ALASKA) VIA THE CANADIAN
ROCKIES AND YUKON VALLEY. A POTENT SHORTWAVE TROUGH IS NESTLED
OVER SOUTHERN NUNAVUT BETWEEN THESE TWO RIDGE AXES. AT THE
SURFACE, THE REMNANTS OF A OCCLUDED LOW WILL BE SITUATED SOMEWHERE
IN THE GULF OF MAINE/CAPE COD AREA. A COLD FRONTAL BOUNDARY
SWEEPS OUT A WIDE ARC FROM NEAR THE REMNANT SURFACE LOW AND
EXTENDING SOUTHWEST TO THE SOUTH CAROLINA COAST, THEN
NORTHWESTWARD OVER THE SOUTHERN APPALACHIANS, TENNESSEE/MID-
MISSISSIPPI VALLEYS AND THEN NORTHWARD INTO THE UPPER MIDWEST. A
RIDGE OF SURFACE HIGH PRESSURE STRETCHES FROM NORTHERN LABRADOR
SOUTHWEST TO THE UPPER GREAT LAKES AND THEN IS NOSED
SOUTH/SOUTHEAST INTO THE LOWER OHIO VALLEY.
BROAD CYCLONIC FLOW AROUND THE UPPER LOW WILL SPREAD A CHILLING
INFLUENCE OVER MOST LOCATIONS EAST OF MISSISSIPPI VALLEY INTO
FRIDAY WHILE ALSO ADVECTING IN SMOKE FROM THE NUMEROUS ONGOING
LARGE WILDFIRES IN THE PARCHED FORESTS OF BOTH WESTERN AND EASTERN
CANADA. EASTERN KENTUCKY WILL BE NO EXCEPTION, THOUGH GUIDANCE
WOULD SUGGEST THAT MOST OF THE SMOKE IN OUR SKIES WILL BE THINNER
AS IT WILL LARGELY ORIGINATE FROM WESTERN CANADA (AFTER RIDING
THOUSANDS OF MILES AROUND THE STRONG RIDGE OVER THE HEART OF THE
CONTINENT). AT THIS POINT, THE THICKER SMOKE FROM THE QUEBEC AND
ONTARIO WILDFIRES MAY LARGELY REMAIN JUST TO OUR NORTHEAST. IN
ADDITION TO THE SMOKY HAZE, GUIDANCE SUGGEST THAT LOW-LEVEL
NORTHERLY FLOW WILL CAUSE UNUSUALLY DRY AIR (BY SUMMER STANDARDS)
TO FILTER IN ON THURSDAY, SENDING DEW POINTS FALLING BACK INTO
MID 30S TO MID 40S, LOWEST ATOP NORTHEAST KENTUCKY RIDGES AND
HIGHEST WEST OF I-75. THURSDAY'S HIGH TEMPERATURES ARE EXPECTED TO
BE ON THE COOL SIDE DUE TO THE AIR MASS'S CANADIAN ORIGINS AND
POTENTIAL SHADING EFFECTS OF THE SMOKE -- MOSTLY IN THE LOWER TO
MIDDLE 70S, EVEN WITH OTHERWISE MOSTLY CLEAR SKIES. SURFACE HIGH
PRESSURE OVER THE OHIO RIVER STRENGTHENS A LITTLE MORE INTO
EASTERN KENTUCKY ON THURSDAY NIGHT. THIS WILL LEAD TO EFFICIENT
RADIATIONAL COOLING AND POTENTIALLY THE CHILLIEST TEMPERATURES WE
HAVE SEEN SINCE MID OR EARLY MAY. LOOKING FOR WIDESPREAD LOWS IN
THE MIDDLE TO UPPER 40S. READINGS BETWEEN 40 AND 45 ARE POSSIBLE
IN THE COLDEST SHELTERED HOLLOWS. MOSTLY SUNNY AND DRY WEATHER
CONTINUES ON FRIDAY, THOUGH TEMPERATURES BEGIN TO MODERATE,
PEAKING IN THE MIDDLE AND UPPER 70S DURING THE AFTERNOON.
THE WARMING TREND WILL CONTINUE FRIDAY NIGHT AND SATURDAY AS THE
PERSISTENT UPPER LEVEL LOW TO OUR NORTHEAST FINALLY EJECTS
NORTHEAST TOWARD NEWFOUNDLAND. AS THIS OCCURS, FLOW OVER THE OHIO
VALLEY BRIEFLY TURNS QUASI-ZONAL SATURDAY NIGHT. MEANWHILE THE
500H SHORTWAVE TROUGH OVER SOUTHERN NUNAVUT DIGS INTO THE 500H
RIDGE ANCHORED OVER THE HEART OF THE CONTINENT WHILE DROPPING
TOWARD THE OHIO VALLEY WHERE IT WILL CLOSE OFF INTO ANOTHER LOW
EARLY IN THE UPCOMING WEEK. SOUTHWESTERLY RETURN FLOW WILL
COMMENCE FRIDAY NIGHT AND CONTINUE INTO SUNDAY OR SUNDAY NIGHT
WHEN A COLD FRONT, PRECEDING THE AFOREMENTIONED CLOSED LOW, SWEEPS
ACROSS THE AREA. TEMPERATURES WARM FURTHER INTO THE LOWER AND
MIDDLE 80S ON SATURDAY AND PERHAPS AGAIN ON SUNDAY. NIGHTTIME LOWS
RECOVER SIMILARLY, RANGING INTO THE MID 40S TO MID 50S FRIDAY
NIGHT AND MID 50S TO MID 60S ON SATURDAY NIGHT. PWATS ALSO RISE
BACK TO BETWEEN THE 50TH AND 90TH PERCENTILE BY LATE SUNDAY OR
SUNDAY NIGHT, FINALLY SETTING THE STAGE FOR SOME MUCH-NEEDED
RAINFALL. WITH THAT SAID, MODELS CONTINUE TO OFFER VARYING
SOLUTIONS WITH REGARD TO THE DEVELOPMENT OF A POTENTIAL LOW
PRESSURE SYSTEM ALONG THE COLD FRONT AS IT MOVES THROUGH THE OHIO
VALLEY. THIS WILL, IN PART, HAVE SOME INFLUENCE ON HOW
PROGRESSIVELY THE FRONT MOVES THROUGH OUR AREA ON SUNDAY OR SUNDAY
NIGHT AND THUS THE AMOUNT OF RAIN WHICH ACTUALLY FALLS. THE GEPS,
EPS AND GEFS ALL SUPPORT A HIGH PROBABILITY (GREATER THAN 70%)
FOR AT LEAST A WETTING RAIN (0.10 INCH OR MORE) AND A MODERATE
PROBABILITY (GREATER THAN 40%) FOR 0.50 INCH OR MORE. ONCE THAT
FRONT DEPARTS, MOST LIKELY EARLY MONDAY, SKIES SHOULD CLEAR OUT
FOR A TIME IN THE LOW'S DRY SLOT. THERE IS SOME POTENTIAL FOR
WRAP-AROUND MOISTURE TO WORK BACK IN NEAR THE CORE OF THE UPPER
LOW MONDAY NIGHT AND TUESDAY, THOUGH THIS IS FAR FROM CERTAIN
GIVEN A RECENT NORTHERLY TREND IN THE MODELED UPPER LOW TRACK. IF
THE WRAPAROUND MOISTURE DOES MAKE IT INTO OUR AREA, COLD-CORE
SHOWER ACTIVITY IS PROBABLE MONDAY NIGHT OR TUESDAY. BEHIND THE
FRONT, TEMPERATURES FALL BACK INTO THE 70S FOR HIGHS WITH LOWS
MAINLY IN THE 50S.
AVIATION
(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 814 PM EDT TUE JUN 6 2023
VFR CONDITIONS WILL HANG ON THROUGH THE MAJORITY OF THE NIGHT,
WITH LOWERING CEILINGS AS A COLD FRONT DROPS SOUTH ACROSS THE
AREA. SOME SCATTERED SHOWERS WILL THREATEN AS EARLY AS MIDNIGHT UP
NORTH, BUT THE STEADIER BOUT OF PRECIPITATION WILL ARRIVE AROUND
08Z, AND THEN SAG SOUTH AND EXPAND MORE SO TOWARDS KSME AND KLOZ
DURING THE DAY ON WEDNESDAY. CONDITIONS WILL BOTTOM OUT IN THE
LOW-END MVFR RANGE, WITH A RETURN OF VFR FROM NORTH TO SOUTH FROM
LATE WEDNESDAY MORNING NEAR KSYM, TO THE END OF THE PERIOD FOR
LOCATIONS BORDERING TENNESSEE AND VIRGINIA. WINDS WILL AVERAGE
AROUND 5 KTS OR LESS, INITIALLY OUT OF THE SOUTHWEST TO WEST
SOUTHWEST AHEAD OF THE FRONT, AND THEN SHIFTING TO THE NORTHWEST
BEHIND THE DEPARTING BOUNDARY.
JKL WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...GEOGERIAN
SHORT TERM...HAL
LONG TERM...GEERTSON
AVIATION...GEOGERIAN
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