441
FXUS61 KILN 141033
AFDILN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
633 AM EDT FRI MAY 14 2021
SYNOPSIS
HIGH PRESSURE AND DRY CONDITIONS WILL PREVAIL ACROSS THE REGION
TODAY INTO SATURDAY. A FRONTAL BOUNDARY WILL MOVE INTO THE OHIO
VALLEY SUNDAY INTO MONDAY, BRINGING A CHANCE OF SHOWERS TO THE
REGION THROUGH THE EARLY PART OF THE UPCOMING WEEK.
NEAR TERM /UNTIL 6 PM THIS EVENING/
SURFACE HIGH PRESSURE IS IN PLACE ACROSS THE REGION THIS
MORNING. WHILE OUR AREA IS GENERALLY CLEAR THIS MORNING, THERE
IS SOME VERY WEAK MID LEVEL TROUGHING OVERHEAD WITHIN THE
BROADER RIDGE ALOFT AND THIS COULD RESULT IN SOME SPOTTY MID
LEVEL CLOUDS THROUGH MID MORNING. EXPECT ANY MID LEVEL CLOUDS
TO DISSIPATE/EVAPORATE AWAY THOUGH AS WE PROGRESS THROUGH LATE
MORNING. WE SHOULD THEN SEE A FEW DIURNAL CU DEVELOP AGAIN AS
WE HEAD INTO THIS AFTERNOON. TEMPERATURES WILL CONTINUE TO
SLOWLY MODERATE WITH HIGHS TODAY IN THE UPPER 60S TO AROUND 70
DEGREES.
SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/
THE SURFACE HIGH WILL BEGIN TO SHIFT OFF TO THE EAST/SOUTHEAST
TONIGHT INTO SATURDAY AS SOME MID LEVEL ENERGY SPREADS IN FROM
THE WEST. THE AIRMASS ACROSS OUR AREA WILL REMAIN ON THE DRY
SIDE THROUGH THROUGH THE DAY ON SATURDAY SO GENERALLY JUST
EXPECT TO SEE AN INCREASE IN SOME MID AND HIGHER LEVEL CLOUDS.
THE GRADUAL WARMING TREND WILL CONTINUE WITH LOWS TONIGHT IN THE
MID 40S AND HIGHS ON SATURDAY IN THE LOWER 70S.
LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/
ON SATURDAY NIGHT, A GENERALLY WEAK SURFACE PRESSURE PATTERN WILL BE
IN PLACE ACROSS THE EASTERN HALF OF THE CONUS, WITH HIGH PRESSURE
OFF THE EAST COAST. LOOKING FURTHER ALOFT, THERE WILL ALREADY BE
SOME CHANGES OCCURRING WITH THE WEATHER PATTERN. RIDGING OVER THE
SOUTHEASTERN STATES WILL COMBINE WITH A SHORTWAVE MOVING INTO THE
GREAT LAKES TO PROVIDE A GENERAL FEED OF MOISTURE FROM THE WESTERN
GULF COAST THROUGH THE MIDDLE MISSISSIPPI VALLEY, AND EVENTUALLY
INTO THE OHIO VALLEY. THETA-E ADVECTION IN THE 925MB-850MB LAYER IS
EXPECTED TO INCREASE OVER THE ILN FORECAST AREA LATE SATURDAY NIGHT
INTO SUNDAY MORNING, WITH THIS DEVELOPING WARM FRONT ACTING AS A
FOCUS FOR SCATTERED PRECIPITATION EARLY SUNDAY. THIS FRONT WILL NOT
BE MOVING TOO QUICKLY -- AND IN FACT, RECENT MODEL RUNS CONTINUE THE
TREND OF LARGELY STALLING IT OVER THE SOUTHERN PARTS OF THE ILN CWA
ON SUNDAY AND INTO MONDAY. ANY WEAK DISTURBANCES IN THE MID-LEVEL
FLOW WILL LIKELY HELP TO KICK OFF SHOWERS ATOP THIS LOW-LEVEL
FRONTAL ZONE, BUT OVERALL POPS WILL BE LIMITED TO THE CHANCE
CATEGORY THROUGH THE DAYTIME HOURS ON SUNDAY, WITH GENERALLY WEAK
BOUNDARY LAYER FORCING. WITH CLOUDS AND PRECIPITATION, AND
SOUTHEASTERLY SURFACE WINDS, MAX TEMPS WILL LIKELY ONLY REACH THE
MIDDLE TO UPPER 60S -- SLIGHTLY LOWER THAN SATURDAY.
THE FORECAST FOR MONDAY REMAINS SOMEWHAT COMPLICATED, AS ANOTHER
SHORTWAVE MOVES INTO THE AREA ATOP THE FRONTAL ZONE. STILL SEEING
SOME DIFFERENCES BETWEEN MODELS ON JUST HOW FAR NORTH THE FRONT WILL
GET, IF IT WILL EVEN MOVE MUCH AT ALL. IT DOES APPEAR THAT
PRECIPITATION IS LIKELY DURING THE DAY ON MONDAY, WITH SOME THUNDER
ALSO POSSIBLE (PARTICULARLY FURTHER SOUTH). FIGURING OUT THE
PLACEMENT OF THE HEAVIEST RAIN (PERHAPS OVER AN INCH) IS SOMETHING
THAT WILL HAVE TO BE REFINED IN FUTURE FORECAST UPDATES. WOULD
PREFER NOT TO INCLUDE A HUGE JUMP IN TEMPERATURES FROM SUNDAY TO
MONDAY, BUT A SLIGHTLY MODIFIED AIR MASS SHOULD ALLOW FOR MAX TEMPS
NEAR 70. A GRADUAL DIMINISHING TREND IN FORCING (AND PRECIPITATION
CHANCES) IS EXPECTED LATER MONDAY NIGHT INTO TUESDAY.
WHILE FORECAST UNCERTAINTY INCREASES FROM TUESDAY AND BEYOND, THERE
SEEMS TO BE GENERAL AGREEMENT IN AN AMPLIFYING PATTERN, WITH THE
OHIO VALLEY LIKELY TO BE CAUGHT AT LEAST SOMEWHAT IN THE MIDDLE OF
THE UPSTREAM TROUGH AND DOWNSTREAM RIDGE. THIS SUPPORTS INCREASING
WARMTH / MOISTURE / INSTABILITY FOR THE SECOND HALF OF THE WEEK. BY
WEDNESDAY AND THURSDAY, BOTH THE GFS AND ECMWF SHOW A LARGELY
MERIDIONAL FLOW PATTERN OVER THE MIDDLE OHIO VALLEY REGION. THIS
FORECAST WILL CONTINUE TO CARRY LOW-END POPS EACH DAY ON TUESDAY,
WEDNESDAY, AND THURSDAY. THIS FORECAST WILL ALSO CARRY WARMING
TEMPERATURES EACH DAY, WITH HIGHS LIKELY TO REACH THE UPPER 70S ON
THURSDAY IF CLOUDS AND PRECIPITATION DO NOT ADVERSELY AFFECT
INSOLATION.
AVIATION /12Z FRIDAY THROUGH TUESDAY/
SURFACE HIGH PRESSURE WILL SHIFT SLOWLY SOUTHEAST ACROSS THE
REGION TODAY INTO SATURDAY. SOME PATCHY RIVER VALLEY FOG HAS
DEVELOPED AGAIN THIS MORNING AND THIS MAY BRIEFLY AFFECT KLUK
NEAR THE START OF THE TAF PERIOD BEFORE DISSIPATING. OTHERWISE,
EXPECTED A FEW DIURNAL CU LATER THIS MORNING INTO THIS
AFTERNOON. ANY CU WILL DISSIPATE TOWARD SUNSET WITH MOSTLY
CLEAR SKIES EXPECTED OVERNIGHT.
OUTLOOK
MVFR CEILINGS POSSIBLE SUNDAY THROUGH TUESDAY.
ILN WATCHES/WARNINGS/ADVISORIES
OH...NONE.
KY...NONE.
IN...NONE.
SYNOPSIS...JGL
NEAR TERM...JGL
SHORT TERM...JGL
LONG TERM...HATZOS
AVIATION...JGL
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