066
FXUS61 KILN 150712
AFDILN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
212 AM EST SUN DEC 15 2024
SYNOPSIS
A MILD AND SOGGY WEATHER PATTERN WILL PREVAIL THROUGH THE FIRST
HALF OF THE UPCOMING WEEK, WITH DRIER AND COLDER CONDITIONS
EXPECTED TOWARD THE END OF THE WEEK. UNTIL THEN, SEVERAL SYSTEMS
WILL BRING WIDESPREAD STEADY RAIN TO THE REGION, WITH ABOVE
NORMAL TEMPERATURES THROUGH MIDWEEK.
NEAR TERM /THROUGH TODAY/
WIDESPREAD STEADY RAIN HAS OVERSPREAD THE ILN FA THIS MORNING,
COURTESY OF LARGE-SCALE FORCING AND ROBUST MOISTURE TRANSPORT
AND MOISTURE/MASS CONVERGENCE ON THE NOSE OF A 40-50KT H8 LLJ.
THIS RAIN WILL CONTINUE THROUGH DAYBREAK BEFORE BECOMING MORE
SCATTERED IN NATURE TOWARD 15Z AND BEYOND AS THE LIFT WEAKENS.
IN FACT, LATEST INDICATIONS SHOW MAINLY ISO SHRA LINGERING IN
THE AREA BY MID AFTERNOON, PARTICULARLY ACROSS THE TRI-STATE
INTO SE IN WHERE DRIER CONDITIONS SHOULD EVOLVE LATE IN THE DAY.
TOTAL RAINFALL THROUGH MID/LATE AFTERNOON SHOULD GENERALLY BE
ON THE ORDER OF 1/2 TO 3/4 OF AN INCH, WITH RAINFALL RATES OF
GENERALLY A TENTH OF AN INCH OR LESS PER HOUR THROUGH SUNRISE.
ALTHOUGH "DRIER" CONDITIONS WILL EVOLVE FOR THIS EVENING,
SUFFICIENT LL MOISTURE WILL REMAIN ENTRENCHED LOCALLY AMIDST
LINGERING SUBTLE LIFT, WHICH MAY LEAD TO THE DEVELOPMENT OF
SOME PATCHY DRIZZLE THIS EVENING INTO TONIGHT. AT THE VERY
LEAST, AMPLE LL SATURATION WILL YIELD LOW CEILINGS AND SOME
MISTY CONDITIONS THIS EVENING/TONIGHT.
TEMPERATURES THIS AFTERNOON WILL TOP OUT IN THE UPPER 40S TO
LOWER 50S AND SHOULDN'T DIP TOO MUCH TONIGHT, PERHAPS ONLY A FEW
DEGREES.
SHORT TERM /TONIGHT THROUGH 6 PM MONDAY/
A BRIEF RESPITE WILL EVOLVE TONIGHT AS MIDLEVEL RIDGING MOVES IN,
ALTHOUGH PATCHY FOG AND/OR DRIZZLE SHOULD DEVELOP ACROSS AT
LEAST PARTS OF THE AREA. THE MAIN ITEM OF INTEREST FOR THE SHORT
TERM PERIOD IS GOING TO BE THE ARRIVAL OF ANOTHER ROUND OF
RAIN, THIS TIME DURING THE DAYTIME MONDAY.
FOLLOWING THE DEPARTURE OF THE WEAKENING CLOSED LOW TO THE E
TONIGHT, A DEEPENING/DIGGING TROF IN THE UPPER MIDWEST WILL PUT
THE OH VLY IN A FAVORABLE LOCATION FOR INCREASING LARGE-SCALE
ASCENT/FORCING WITH SUFFICIENT MOISTURE/MOISTURE TRANSPORT NE
INTO THE REGION ON MONDAY. ALTHOUGH THE NEXT ROUND OF RAIN WILL
BE FAIRLY PROGRESSIVE, SOME BRIEF MODERATE TO LOCALLY HEAVY
RAIN RATES WILL BE POSSIBLE, PARTICULARLY NEAR/S OF THE I-71
CORRIDOR. THE ACTIVITY ON MONDAY SHOULD BE MORE SHOWERY IN
NATURE, WITH AN INITIAL SURGE OF WIDESPREAD SHOWERS AFTER
DAYBREAK INTO MID AFTERNOON, WITH ADDITIONAL SCT ACTIVITY
FOCUSING ALONG THE EASTWARD-ADVANCING FRONT DURING THE EVENING.
LATEST GUIDANCE, INCLUDING ENSEMBLE DATASETS, SUGGEST ONLY
MARGINAL POTENTIAL FOR NEAR/GREATER THAN 1" OF RAIN ON MONDAY
WITH GREATEST PROBS (STILL GENERALLY <20%) NEAR/S OF I-71,
PARTICULARLY WITHIN A CORRIDOR NEAR SWITZERLAND CO IN TO ROSS CO
OH AND POINT FURTHER S. OF COURSE, THE PROSPECT OF AN INCH OF
RAIN TYPICALLY WOULDN'T RAISE ANY EYEBROWS, BUT IT WILL BE
COMING IMMEDIATELY ON THE HEELS OF THE WIDESPREAD 1/2 TO 3/4 OF
AN INCH TODAY, SO SOILS ARE EXPECTED TO BECOME INCREASINGLY
SOGGY/SATURATED AND LESS RECEPTIVE TO ABSORPTION SHOULD TOTALS
(BETWEEN RIGHT NOW AND MONDAY EVENING) APPROACH 2." THIS COULD
LEAD TO SOME ISOLATED RUNOFF ISSUES AND, AT THE VERY LEAST,
SHOULD CAUSE SOME RISES ON AREA WATERWAYS. BUT AT THIS JUNCTURE,
GIVEN THE DECREASE IN SIGNAL FOR A HEAVIER (>= 1") SWATH OF
RAIN, EVEN ACROSS THE SE THIRD OF THE ILN FA, THERE IS JUST NOT
ENOUGH OF A SIGNAL TO WARRANT A BIGGER CONCERN FOR LARGER-
SCALE/WIDESPREAD FLOODING CONCERNS.
DRIER CONDITIONS EVOLVE TOWARD LATER MONDAY EVENING FOLLOWING
THE FROPA, WITH SLIGHTLY COOLER/DRIER AIR FILTERING IN FOR
MONDAY NIGHT.
LONG TERM /MONDAY NIGHT THROUGH SATURDAY/
NEGATIVELY TILTED TROUGH ASSOCIATED WITH AN ACTIVE 500H WAVE TRAIN
PATTERN WILL BE MOVING THROUGH THE GREAT LAKES AND ONTARIO WITH ITS
ASSOCIATED SURFACE FEATURE DRAGGING AN OCCLUDED/ COLD FRONT THROUGH
THE OHIO VALLEY. THE COLDEST 850MB AIR REMAINS WELL NORTH OF THE
CWA, HOWEVER, WE'LL FEEL SOME SUBTLE COLD AIR ADVECTION ON THE
BACKSIDE OF THE SYSTEM AND OVERNIGHT LOWS DROP INTO THE MID 30S.
TUESDAY ARRIVES DRY WITH HIGHS IN THE 40S AS WE ARE IN BETWEEN
WAVES, HOWEVER THIS LULL IS BRIEF.
THE NEXT DISTURBANCE BEGINS TO DIG IN AND RAIN WILL MOVE BACK INTO
THE REGION BY TUESDAY OVERNIGHT INTO WEDNESDAY. ENSEMBLE (AND
DETERMINISTIC) GUIDANCE HAS BEEN STRUGGLING WITH THIS SYSTEM. THE
ECMWF CONSISTENTLY PUSHING THE HIGHEST QPF FOOTPRINT TO OUR SOUTH,
ALONG THE KY/TN BORDER WITH THE GFS HOLDING ONTO A MORE NORTHERLY
SOLUTION. IT SHOULD BE NOTED THAT TONIGHT'S 00Z GFS HAS TRENDED A
TAD FARTHER SOUTH, SO THAT LENDS A BIT MORE CONFIDENCE TO THE
SOUTHERLY SOLUTION. SENSIBLY SPEAKING, MUCH OF THE AREA WILL RECEIVE
RAINFALL AS WE HEAD INTO WEDNESDAY MORNING AND THROUGH THE DAY ON
WEDNESDAY (TEMPS IN THE 40S-50S), BUT HIGHEST CONFIDENCE WILL BE FOR
AREAS ALONG THE OHIO RIVER. POPS DECREASE WEDNESDAY EVENING BEHIND A
MUCH STRONGER COLD FRONT AND WE MAY EVEN SEE SOME WINTRY MIX AS
THINGS WIND DOWN. ALONG THIS LINE OF THOUGHT, THIS SYSTEM CARRIES
COLD AIR MUCH FARTHER SOUTH, AND OUR 850MB TEMPS MIGHT END UP AROUND
-10 TO -14 RANGE WITH WEDNESDAY NIGHT SURFACE TEMPS DROPPING TO THE
20S.
AGAIN, DO WANT TO MENTION THAT WITH SAT/SUN OVERNIGHT RAIN, MONDAY
RAIN, AND THIS POTENTIAL ADDITIONAL RAIN (HIGHEST ALONG THE OHIO
RIVER?) WE'LL NEED TO KEEP AN EYE ON ANY HYDRO CONCERNS.
THURSDAY ARRIVES MUCH COOLER, WITH HIGHS ONLY REACHING THE LOW TO
MID 30S WITH PERHAPS SOME LINGERING FLURRIES IN THE RESIDUAL
CYCLONIC FLOW, BUT SIGNAL ISN'T STRONG ENOUGH TO INCLUDE IN THE
FORECAST JUST YET.
YET ANOTHER WAVE MOVES THROUGH THE NORTHERLY FLOW AS A CLIPPER-TYPE
SYSTEM LOOKS TO MOVE INTO THE REGION NEAR THE END OF THE WORK WEEK.
WE'RE A BIT FAR OUT FOR DETAILS CURRENTLY, BUT THE ACTIVE PATTERN
DOES SEEM TO BE RELENTLESS!
AVIATION /07Z SUNDAY THROUGH THURSDAY/
AN EXPANSIVE SHIELD OF RA CONTINUES TO OVERSPREAD THE LOCAL
AREA, WITH VFR CIGS TO TRANSITION TO MVFR, AND EVENTUALLY IFR,
BY/AROUND 12Z AREA-WIDE. THE STEADIER/HEAVIER POCKETS OF RA
WILL LEAD TO MVFR VSBYS, WITH THE POTENTIAL FOR BRIEF IFR VSBYS
IN THE HEAVIEST ACTIVITY. IFR CIGS ARE EXPECTED TO SETTLE INTO
THE REGION FOR THE DAYTIME, WITH SOME LIFR CIGS POSSIBLE AS
WELL, ESPECIALLY FOR NRN SITES, BY LATE IN THE DAYTIME AND
TOWARD 06Z MONDAY.
SOME PATCHY SOUTHERLY LLWS ON THE ORDER OF 40-45KTS IS EXPECTED
THROUGH DAYBREAK, WITH SFC WINDS GENERALLY OUT OF THE SE AT
10-12KTS. THESE WINDS WILL GRADUALLY SUBSIDE BY/AFTER 00Z TO
LESS THAN 10KTS, GOING MORE SOUTHERLY BY THE END OF THE PERIOD.
THE SOLID SHIELD OF RA WILL TRANSITION TO MORE SHOWERY IN NATURE
AFTER 12Z, WITH SCT TO NUMEROUS SHRA LINGERING ABOUT ABOUT
15Z-18Z. SOME PATCHY DZ MAY DEVELOP AFTER 00Z AND LINGER INTO
EARLY MONDAY, BUT CONFIDENCE WAS NOT YET HIGH ENOUGH TO INCLUDE
IN THE FCST AT THIS JUNCTURE. IFR/LIFR CIGS, WITH MVFR/IFR VSBYS
WILL BE POSSIBLE BY 06Z MONDAY AMIDST PATCHY BR/DZ.
OUTLOOK...MVFR TO IFR CONDITIONS ARE LIKELY MONDAY INTO MONDAY
NIGHT, AND AGAIN ON WEDNESDAY. SOME MVFR CIGS MAY LINGER INTO
WEDNESDAY NIGHT.
ILN WATCHES/WARNINGS/ADVISORIES
OH...NONE.
KY...NONE.
IN...NONE.
SYNOPSIS...KC
NEAR TERM...KC
SHORT TERM...KC
LONG TERM...CA
AVIATION...KC
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