781
FXUS61 KILN 200608
AFDILN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
208 AM EDT WED MAR 20 2019
SYNOPSIS
HIGH PRESSURE WILL GRADUALLY MOVE EAST OF THE REGION TONIGHT. A
MID-LEVEL TROUGH WILL MOVE INTO THE AREA ON WEDNESDAY, BRINGING
SHOWERS TO THE AREA THROUGH EARLY THURSDAY. A LARGE AREA OF HIGH
PRESSURE WILL THEN MOVE INTO THE AREA LATE THURSDAY, PERSISTING
THROUGH THE WEEKEND. THIS WILL BRING DRY WEATHER AND GRADUALLY
WARMING TEMPERATURES.
NEAR TERM /UNTIL 6 AM THIS MORNING/
SURFACE HIGH PRESSURE WILL CONTINUE TO MOVE EAST TONIGHT. CLOUDS
WILL GRADUALLY INCREASE, HIGH CLOUDS FIRST, THEN BY SOME MID
CLOUDS MIXING IN. WINDS WILL BE LIGHT/VARIABLE/CALM THEN OUT OF
THE SOUTHEAST/SOUTH AROUND 5 KNOTS LATE. TEMPERATURES SHOULD
STAY A FEW DEGREES WARMER THAN LAST NIGHT, WITH MIN TEMPS
GENERALLY IN THE LOWER 30S. SOME UPPER 20S ARE EXPECTED IN
OUTLYING AREAS, ESPECIALLY IN CENTRAL OHIO.
SHORT TERM /6 AM THIS MORNING THROUGH 6 AM THURSDAY/
THOUGH MID-LEVEL FLOW THROUGH THE OHIO VALLEY AND EASTWARD WILL
BE PSEUDO-ZONAL ON WEDNESDAY MORNING, ATTENTION WILL TURN TO A
SHARP SHORTWAVE TROUGH MOVING INTO THE MIDDLE MISSISSIPPI
VALLEY. WITH SURFACE HIGH PRESSURE MOVING EAST OF THE AREA,
SOUTHERLY / SOUTHWESTERLY FLOW INTO THE OHIO VALLEY IS EXPECTED
TO INCREASE IN INTENSITY, BRINGING WARMTH AND MOISTURE INTO THE
REGION AHEAD OF THE TROUGH. ANOTHER TROUGH MOVING THROUGH THE
GREAT LAKES LATER ON WEDNESDAY WILL EVENTUALLY PHASE WITH THE
SOUTHERN TROUGH, WITH GFS/NAM PROJECTIONS EXPECTING THIS TO
OCCUR AS THE SYSTEM MOVES ACROSS THE ILN FORECAST AREA LATE
WEDNESDAY AFTERNOON INTO THE EVENING. CONFIDENCE HAS INCREASED
IN THE EXPECTATION FOR A BAND (OR SEVERAL BROKEN BANDS) OF
SHOWERS MOVING ACROSS THE AREA, AND POPS HAVE BEEN INCREASED TO
THE LIKELY CATEGORY FOR THE ENTIRE ILN CWA. THERE ARE STILL SOME
TIMING DIFFERENCES REGARDING THE ONSET OF PRECIPITATION, WITH
QUICKER SCENARIOS DEPICTED BY THE WRF-NMM AND GFS, AND SLOWER
SCENARIOS BY THE WRF-ARW AND NAM. OVERALL, THE TREND HAS BEEN
SLIGHTLY SLOWER, SO POPS WERE DELAYED UNTIL AFTERNOON -- AND THE
GREATEST CHANCE FOR PRECIPITATION NOW APPEARS TO RANGE FROM 00Z
TO 06Z.
IN TERMS OF TEMPERATURES, THE THINKING HERE HAS NOT CHANGED MUCH
FROM THE PREVIOUS FORECAST, WITH ADVECTION OUTPERFORMING THE
LIMITED INSOLATION AND ALLOWING FOR MAX TEMPS IN THE 50S. THE
FAR SOUTHEASTERN SECTIONS OF THE CWA MAY APPROACH 60 DEGREES,
ESPECIALLY IF THERE ARE SOME BREAKS IN THE CLOUDS THROUGH THE
FIRST HALF OF THE DAY.
A SURFACE COLD FRONT WILL FOLLOW THE MAIN BAND OF PRECIPITATION,
WITH COLD FRONTAL PASSAGE EXPECTED LATE WEDNESDAY NIGHT INTO
EARLY THURSDAY MORNING. THIS FRONT WILL LIKELY STILL BE WITHIN
THE FORECAST AREA AT 12Z THURSDAY MORNING, AND THE REST OF THIS
WILL BE COVERED IN THE LONG TERM SECTION BELOW. AN ADDITIONAL
BAND OF SHOWERS IS LIKELY TO DEVELOP ALONG THE FRONT, THOUGH,
SO POPS HAVE BEEN MAINTAINED FOR A WHILE EVEN BEHIND THE MAIN
BAND OF PRECIPITATION. THE PRESENCE OF THE FRONT WILL LEAD TO A
MODEST GRADIENT IN TEMPERATURES ON WEDNESDAY NIGHT, RANGING FROM
MID 30S TO MID 40S FROM NORTHWEST TO SOUTHEAST.
LONG TERM /THURSDAY THROUGH TUESDAY/
THE MID AND UPPER LEVEL TROUGH AXIS WILL PIVOT ACROSS THE UPPER
OHIO VALLEY ON THURSDAY. UNTIL WE GET ON THE BACK SIDE OF THIS,
SOME SCATTERED SHOWER ACTIVITY WILL LIKELY LINGER INTO THE DAY
ON THURSDAY, PARTICULARLY ACROSS OUR EAST. THERMAL PROFILES
SUPPORT MAINLY RAIN BUT SUPPOSE THE BOUNDARY LAYER COULD COOL
OFF JUST ENOUGH TO RESULT IN A BRIEF RAIN/SNOW MIX ACROSS THE
NORTH AROUND DAYBREAK. HIGHS ON THURSDAY WILL RANGE FROM THE MID
40S IN THE NORTHWEST TO THE LOWER 50S IN THE SOUTHEAST.
A WEAKER, SECONDARY SHORT WAVE WILL DROP QUICKLY SOUTHEAST
ACROSS THE SOUTHERN GREAT LAKES THURSDAY NIGHT INTO FRIDAY. WILL
MAINTAIN A DRY FORECAST AT THIS POINT, BUT THIS MAY EVENTUALLY
BE ENOUGH TO INTRODUCE SOME CHANCE POPS ACROSS MAINLY OUR
NORTHEAST THURSDAY NIGHT INTO EARLY FRIDAY. HIGHS ON FRIDAY WILL
RANGE FROM THE MID 40S NORTH TO THE MID 50S ACROSS THE SOUTH.
SURFACE HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST THROUGH
SATURDAY BEFORE SHIFTING OFF TO OUR SOUTHEAST ON SUNDAY. THIS
WILL PROVIDE FOR DRY AND CONTINUED SEASONABLE CONDITIONS ON
SATURDAY WITH HIGHS IN THE MID 40S TO MID 50S. AS WE START TO
GET INTO SOME RETURN FLOW ON THE BACK SIDE OF THE HIGH, HIGHS ON
SUNDAY WILL RANGE FROM THE MID 50S NORTH TO THE LOWER 60S IN
THE SOUTH.
A SURFACE LOW PRESSURE SYSTEM WILL MOVE OUT OF THE CENTRAL
PLAINS THROUGH EARLY NEXT WEEK. THIS WILL LEAD TO AN INCREASING
CHANCE OF SHOWERS SUNDAY NIGHT INTO MONDAY. HIGHS ON MONDAY WILL
BE MAINLY IN THE 50S.
AVIATION /06Z WEDNESDAY THROUGH SUNDAY/
HIGH CLOUDS WILL CONTINUE TO STREAM OVER THE TAFS EARLY THIS
MORNING, WITH SOME MID LEVEL CLOUDS WORKING IN JUST BEFORE
SUNRISE. CEILINGS WILL CONTINUE TO LOWER THROUGHOUT THE DAY
AS A S/W OVER THE CENTRAL PLAINS MERGES WITH A MID LEVEL TROUGH
DIGGING INTO THE WESTERN GREAT LAKES. SOUTH WINDS WILL SEE AN
INCREASE DURING THE DAY REACHING 10 TO 15 KTS WITH SOME GUSTS
AROUND 20KTS.
LATEST MODEL RUNS ARE NOW DELAYING RAIN CHANCE UNTIL AFTER 00Z,
WHEN THE H5 TROUGH MOVES EAST INTO THE LOWER GREAT LAKES AND
OHIO VALLEY. AN AREA OF SHOWERS WILL SWING ACROSS THE TAFS
TONIGHT AHEAD OF A CDFNT. CEILINGS WILL FALL TO MVFR BETWEEN
00-06Z, ALONG WITH SOME MVFR VSBYS IN A SOME OF THE SHOWERS. AS
THE LOW LEVEL CONTINUES TO POOL TONIGHT, IFR CEILINGS WILL BE
POSSIBLE IN THE CVG 30 HOUR TAF.
OUTLOOK...MVFR/IFR CEILINGS LIKELY THURSDAY. MVFR CEILINGS ARE
POSSIBLE THURSDAY NIGHT. GUSTY NORTHWEST WINDS 25 TO 30 KNOTS
POSSIBLE ON FRIDAY.
ILN WATCHES/WARNINGS/ADVISORIES
OH...NONE.
KY...NONE.
IN...NONE.
SYNOPSIS...HATZOS/HICKMAN
NEAR TERM...HATZOS/HICKMAN
SHORT TERM...HATZOS
LONG TERM...JGL
AVIATION...SITES
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