529
FXUS61 KILN 270611
AFDILN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
111 AM EST SAT FEB 27 2021
SYNOPSIS
LOW PRESSURE MOVING THROUGH THE OHIO AND TENNESSEE VALLEYS WILL
BRING PRECIPITATION TO THE REGION THIS EVENING THROUGH THE
OVERNIGHT. ANOTHER, STRONGER WAVE OF LOW PRESSURE WILL PROVIDE
ADDITIONAL RAIN FOR THE LATTER HALF OF THE WEEKEND BEFORE HIGH
PRESSURE CAUSES DRY WEATHER TO RETURN EARLY NEXT WORK WEEK.
NEAR TERM /UNTIL 6 AM THIS MORNING/
MOST OF THE TRADITIONAL SHOWER-TYPE ACTIVITY HAS EXITED THE ILN
FA, LEAVING IN ITS WAKE SOME PATCHY DRIZZLE AND VERY LIGHT RAIN
THROUGH THE FIRST PART OF THE OVERNIGHT PERIOD. MOST SPOTS WON'T
SEE MUCH ADDITIONAL RAIN UNTIL AFTER 3 AM OR SO WHEN SHOWERS
ALONG/JUST AHEAD OF THE FRONT ITSELF MOVE BACK INTO THE AREA
FROM THE WEST. THE TIME WINDOW FOR FAVORED SHOWERS FOR ANY ONE
LOCATION WILL BE ON THE ORDER OF AN HOUR OR TWO AS THE FRONT
PROGRESSES WEST TO EAST THROUGH THE AREA BETWEEN 3 AM AND 8 AM.
WILL ALSO SEE A RESURGENCE OF RAIN IN THE FAR SOUTHEAST,
INCLUDING THE LOWER SCIOTO VALLEY/NORTHEAST KY LATE IN THE
OVERNIGHT PERIOD AS WELL. ADDITIONAL RAINFALL AMOUNTS THROUGH
THE REMAINDER OF THE NEAR TERM PERIOD WILL BE ON THE ORDER OF A
TENTH OR SO, WITH SLIGHTLY MORE POSSIBLE IN A FEW SPOTS. DRIER
CONDITIONS WILL EVOLVE PAST 8 AM AREA-WIDE IN THE POST-FRONTAL
ENVIRONMENT.
LOW TEMPERATURES HAVE LIKELY BEEN REACHED ALREADY THIS EVENING
AND WILL BEGIN TO PLATEAU AND INCH BACK UP LATE IN THE NIGHT AS
SOUTHERLY SURFACE FLOW BECOMES ESTABLISHED AHEAD OF THE
AFOREMENTIONED FRONT. FAIRLY UNIFORM TEMPS ARE EXPECTED
OVERNIGHT IN THE UPPER 30S AND LOWER 40S, WHICH WILL TREND UP BY
A FEW DEGREES BY DAYBREAK. COULD ALSO SEE SOME PATCHY FOG IN
WEST-CENTRAL OHIO AND AREAS NORTH OF I-70 LATE IN THE NEAR TERM
PERIOD AS WELL.
SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/
WEAK HIGH PRESSURE WILL BUILD IN FROM THE SOUTHWEST SATURDAY
AFTERNOON AS AN MID LEVEL TROUGH DIGS SOUTHEAST FROM THE
CENTRAL ROCKIES INTO THE SOUTHERN PLAINS STATES. THIS WILL SHIFT
UPPER LEVEL FLOW TO A MORE SOUTHWEST TO NORTHEAST ORIENTATION
EAST OF THE TROUGH. ENERGY WILL EJECT THROUGH THE SOUTHWESTERLY
FLOW INTO THE OHIO VALLEY SATURDAY NIGHT INTO SUNDAY, BRINGING
MODERATE TO HEAVY RAINFALL. MODEL GUIDANCE STILL SHOWS
SIGNIFICANT UNCERTAINTY AT THIS LATE STAGE, WITH THE GFS
ENSEMBLE PAINTING HIGHEST CHANCES OF 2"+ RAINFALL VERY NEAR THE
OHIO RIVER IN NORTHERN/NORTHEASTERN KENTUCKY, WHILE THE
EUROPEAN ENSEMBLE POSITIONS IT TO THE SOUTH OF THE FORECAST
AREA, THOUGH WITH HIGHER AMOUNTS. HIGH RESOLUTION MODELS SHOW
POTENTIAL FOR TRAINING OF MODERATE TO HEAVY RAIN LATE SATURDAY
NIGHT INTO SUNDAY MORNING IN NORTHEAST KENTUCKY.
DESPITE THE UNCERTAINTY IN POSITION, THE POTENTIAL FOR 1.5" TO
2.5" OF RAIN ON RELATIVELY SATURATED SOILS BRINGS SOME CAUSE FOR
CONCERN WITH AREA STREAMS, ESPECIALLY SOUTH OF THE OHIO RIVER.
PWATS RANGING FROM 1-1.5" DURING THIS TIME, SURFACE DEWPOINTS
LIFTING INTO THE 50S, AND WARM CLOUD DEPTHS INCREASING TO NEAR
10KFT DISPLAY THE STRONG POTENTIAL FOR EFFICIENT WARM RAIN
PROCESSES. WILL CONTINUE TO TRACK THIS RAINFALL EVENT CLOSELY AS
GUIDANCE ZEROES IN ON A MORE CONFIDENT TRACK.
LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/
RAINFALL EVENT WILL BE ONGOING WITH PRIMARY FOCUS ACROSS SOUTHERN
COUNTIES. THERE REMAINS UNCERTAINTY WHERE AXIS OF HEAVIEST RAINFALL
WILL OCCUR WHICH OBVIOUSLY AFFECTS FLOOD POTENTIAL. EXPECT A FAIRLY
SHARP NORTHERN GRADIENT TO HEAVIER RAIN AS WELL. GROUND IS SATURATED
AND RAINFALL HAS THE POTENTIAL TO BE RATHER EFFICIENT. SO IN
COLLABORATION WITH NEIGHBORING KENTUCKY OFFICES, HAVE GONE AHEAD AND
ISSUED A FLOOD WATCH FOR A NUMBER OF NORTHERN KENTUCKY COUNTIES FROM
LATE SATURDAY NIGHT THROUGH SUNDAY. THERE IS THE POSSIBILITY THAT
THIS MAY NEED TO BE ADJUSTED NORTHWARDS A BIT, ESPECIALLY INTO SOUTH
CENTRAL OHIO, IF MORE NORTHERN MODEL SOLUTIONS LOOK MORE LIKELY.
RAIN INTENSITY IS FORECAST TO DIMINISH SUNDAY AFTERNOON, AND
PRECIPITATION WILL COME TO AN END AFTER A COLD FRONT SWEEPS ACROSS
THE AREA LATE SUNDAY AFTERNOON INTO THE EVENING. A SECONDARY
BOUNDARY WILL PUSH THROUGH ON MONDAY WITH HIGH PRESSURE BUILDING
ACROSS THE AREA MONDAY NIGHT AND MOVING EAST ON TUESDAY.
THERE CONTINUES TO BE VARIATIONS IN THE GUIDANCE WHETHER A SYSTEM
PASSES SOUTH OF THE AREA ON TUESDAY NIGHT INTO WEDNESDAY. WILL KEEP
LOW CHANCE POPS FOR THIS TIME PERIOD. TEMPERATURES MAY GET COLD
ENOUGH TUESDAY NIGHT FOR THERE TO BE RAIN OR SNOW. ANOTHER HIGH
BUILDS IN THURSDAY. MID LEVEL FLOW WILL BE AMPLIFYING LATE IN THE
WEEK WITH TROUGHING IN THE EAST. THIS COULD BRING ANOTHER WEAK
SYSTEM THROUGH THE AREA FRIDAY.
AVIATION /06Z SATURDAY THROUGH WEDNESDAY/
WEAK MID LEVEL SHORTWAVE AND ASSOCIATED ISENTROPIC LIFT WILL
RESULT IN AN INCREASED CHANCE FOR SHOWERS OVERNIGHT. AS THE
SHORTWAVE AND WEAK FORCING SHIFTS EAST -- EXPECT PCPN TO END
FROM WEST TO EAST THRU 13Z. MVFR CEILINGS WHICH ARE DROPPING TO
IFR ACROSS THE WESTERN TAF SITES WILL DO SO ACROSS ALL TAF
SITES OVERNIGHT.
THESE IFR CEILINGS WILL LINGER THROUGH THE MORNING HOURS BEFORE
LIFTING TO MVFR BY EARLY AFTERNOON. AS WEAK SURFACE HIGH
PRESSURE BUILDS ACROSS THE AREA THIS AFTN EXPECT TO SEE
CONTINUED IMPROVEMENT. UNCERTAINTY EXISTS IF CLOUDS SCATTER OUT
WITH VFR CONDITIONS DEVELOPING. HAVE KEPT MVFR CONDITIONS AT
KCVG/KLUK WITH A PERIOD OF VFR CONDITIONS AT THE REMAINDER
OF THE TAF SITES LATER IN THE DAY INTO THIS EVENING.
MOISTURE INCREASES LATE THIS EVENING WITH CLOUDS AND RAIN
SHOWERS OVERSPREADING THE AREA FROM THE SOUTHWEST BETWEEN 04Z
AND 09Z. HAVE MVFR TO IFR CONDITIONS REDEVELOPING AT KCVG/KLUK
WITH MVFR AT THE REMAINDER OF THE SITES LATE IN THE TAF PERIOD.
OUTLOOK... MVFR/IFR CIGS AND MVFR VSBYS LIKELY LATE SATURDAY
NIGHT INTO SUNDAY MORNING.
ILN WATCHES/WARNINGS/ADVISORIES
OH...NONE.
KY...FLOOD WATCH FROM LATE TONIGHT THROUGH SUNDAY EVENING FOR
KYZ094>100.
IN...NONE.
SYNOPSIS...HOGUE
NEAR TERM...KC
SHORT TERM...HOGUE
LONG TERM...
AVIATION...AR
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