573  
FXUS61 KILN 231048  
AFDILN  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE WILMINGTON OH  
648 AM EDT SAT MAR 23 2019  
   
SYNOPSIS
 
 
HIGH PRESSURE WILL MOVE INTO THE OHIO VALLEY TODAY, BRINGING  
DRY AND SUNNY CONDITIONS THROUGH SUNDAY MORNING. LATER ON SUNDAY  
AND INTO MONDAY, A WEAKENING AREA OF LOW PRESSURE WILL MOVE  
SOUTHEAST THROUGH THE OHIO VALLEY, BRINGING A CHANCE OF RAIN.  
HIGH PRESSURE WILL MOVE INTO THE AREA AGAIN ON TUESDAY, WITH DRY  
WEATHER EXPECTED THROUGH MOST OF THE WEEK.  
 

 
   
NEAR TERM /THROUGH TONIGHT/
 
 
SURFACE ANALYSIS INDICATES AN AREA OF HIGH PRESSURE CENTERED  
NEAR LAKE MICHIGAN. THIS HIGH IS EXPANSIVE, INFLUENCING  
CONDITIONS ALL THE WAY FROM LAKE WINNIPEG TO THE GULF COAST. THE  
OHIO VALLEY IS CAUGHT IN BETWEEN TWO UPPER LEVEL DISTURBANCES,  
WITH A MID-LEVEL LOW DEPARTING THE NORTHEASTERN STATES TO THE  
EAST, AND A TROUGH SLOWLY DEVELOPING IN THE ROCKIES. A NARROW  
RIDGE IN BETWEEN THE TWO SYSTEMS IS NOW MOVING INTO THE OHIO  
VALLEY, WITH HEIGHTS BEGINNING TO RISE -- AN INDICATION OF WARM  
ADVECTION IN THE 850MB-700MB LAYER. ANY LAST COLD ADVECTION  
STRATOCUMULUS IS NOW WELL OFF TO THE EAST, WITH CIRRUS ON THE  
BACK SIDE OF THE RIDGE STILL WELL UPSTREAM. WITH THIS VERY DRY  
AIR MASS IN PLACE -- PRECIPITABLE WATER VALUES ARE UNLIKELY TO  
REACH EVEN TWO TENTHS OF AN INCH -- IT IS VERY LIKELY THAT SKIES  
WILL REMAIN COMPLETELY CLEAR TODAY. LATE IN THE DAY AND HEADING  
INTO THE EVENING, SOME CIRRUS WILL BEGIN TO MOVE INTO THE AREA.  
 
WITH THE DRY AND SUNNY CONDITIONS, TEMPERATURES SHOULD RESPOND  
WELL, AND MAX TEMPS ARE EXPECTED TO REACH THE UPPER 40S TO  
MIDDLE 50S. IF ANYTHING, THESE NUMBERS COULD EVEN BE A COUPLE  
DEGREES TOO LOW, THOUGH THEY REPRESENT A SLIGHT INCREASE FROM  
THE PREVIOUS FORECAST. MAV/GFS NUMBERS LOOK A LITTLE MORE  
REASONABLE (AND WARMER) THAN NAM/SREF MEAN NUMBERS.  
 

 
   
SHORT TERM /SUNDAY/
 
 
A DEAMPLIFYING RIDGE AXIS WILL BE DIRECTLY OVERHEAD THIS  
EVENING OVER THE ILN FORECAST AREA, WITH SURFACE HIGH PRESSURE  
BEGINNING TO MOVE OFF TO THE SOUTHEAST. ON THE BACK SIDE OF THE  
RIDGE, CIRRUS CLOUDS ARE EXPECTED TO BE SPILLING INTO THE  
REGION, BUT THE LOW LEVELS WILL REMAIN VERY DRY HEADING INTO THE  
OVERNIGHT HOURS. RADIATIONAL COOLING CONDITIONS WILL ACTUALLY  
BE BETTER AT THE START OF THE OVERNIGHT PERIOD, BEFORE THE  
CLOUDS BECOME A LITTLE THICKER, AND BEFORE SOME LIGHT SSE FLOW  
BEGINS TO DEVELOP AS THE HIGH MOVES AWAY. FOR THIS REASON, MIN  
TEMPS MAY ARRIVE CLOSE TO 06Z, WITH STEADY OR SLIGHTLY WARMING  
TEMPERATURES THROUGH SUNDAY MORNING. DEPENDING ON HOW THIS  
TIMING ACTUALLY WORKS OUT, THE MIN TEMPS COULD VARY A BIT FROM  
THIS FORECAST, BUT ARE GENERALLY EXPECTED TO BE IN THE LOWER TO  
MIDDLE 30S.  
 
THE MID-LEVEL FLOW OVER THE EASTERN HALF OF THE COUNTRY WILL BE  
FLATTENING OUT ON SUNDAY, AS A WEAKENING MID-LEVEL LOW OPENS  
INTO A WAVE OVER THE MIDDLE MISSISSIPPI VALLEY REGION. PERHAPS  
AS A RESULT OF THIS INCREASINGLY DAMPENED SOLUTION, THE FORWARD  
PROGRESSION OF THIS SYSTEM IS BEING HANDLED A BIT FASTER IN  
RECENT MODEL RUNS, WITH THE INITIAL BATCH OF WARM ADVECTION  
PRECIPITATION IMPINGING ON THE ILN FORECAST AREA AS EARLY AS  
12Z-15Z ON SUNDAY MORNING. POP TIMING WAS ADJUSTED TO ACCOUNT  
FOR THIS, AND THERE WERE SOME CHANGES TO TEMPERATURE GRIDS AS  
WELL, WITH MORE OF A GRADIENT IN PLACE THAN BEFORE. AS IT LOOKS  
NOW, ONLY THE SOUTHEASTERN SECTIONS OF THE ILN CWA APPEAR LIKELY  
TO REMAIN OUT OF THE THICKER MID-LEVEL CLOUDS AND POTENTIAL  
PRECIPITATION THROUGH THE AFTERNOON, AND THESE AREAS WILL LIKELY  
SEE THE WARMEST TEMPERATURES -- CLOSE TO 60 DEGREES. 50S ARE  
EXPECTED ELSEWHERE.  
 

 
   
LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/
 
 
FOR SUNDAY NIGHT, A S/WV WILL GET NUDGED EAST BY A LARGE SCALE  
MID LEVEL TROUGH DIGGING SOUTHWARD INTO THE GREAT LAKES AND NEW  
ENGLAND. WEAK LOW PRESSURE WITH THE S/WV WILL COMBINED WITH A  
SOUTHWARD MOVING COLD FRONT TO BRING CATEGORICAL POPS TO THE  
REGION. MODELS HAVE TRENDED A LITTLE COLDER WITH AIR FILTERING  
IN FROM THE NORTH, SO SOME OF THE PRECIPITATION ACROSS THE FAR  
NORTH MAY MIX WITH A LITTLE SNOW LATE. LOWS WILL RANGE FROM THE  
LOWER 30S FAR NORTH TO THE UPPER 40S FAR SOUTH.  
 
ON MONDAY, THE WEAK LOW AND COLD FRONT WILL CONTINUE TO PUSH  
SOUTHEAST. THIS WILL ALLOW PCPN TO TAPER OFF FROM THE NORTH  
DURING THE DAY AS DRIER AIR FILTERS IN. AGAIN, MODELS HAVE  
TRENDED A LITTLE COLDER WITH THE LOW LEVELS OF THE ATMOSPHERES,  
AND A LITTLE BIT OF SNOW MAY MIX IN ALONG AND NORTH OF I-70  
BEFORE PCPN TAPERS OFF BY AFTERNOON. IT SHOULD REMAIN IN LIQUID  
FORM ACROSS THE SOUTH. TEMPERATURES WILL BE TRICKY GIVEN INITIAL  
CAA, BUT WITH CLEARING SKIES FROM THE NORTH AND SOME SUNSHINE  
EXPECTED FOR ALL LOCATIONS BEFORE THE SUN SETS, THE SUNSHINE MAY  
OFF SET THIS CAA SLIGHTLY. WITH A BRISK NORTHEAST WIND GUSTING  
BETWEEN 20 AND 30 MPH, HIGHS WILL RANGE FROM THE LOWER 40S NORTH  
TO NEAR 50 SOUTH.  
 
FOR MONDAY NIGHT INTO TUESDAY, A LARGE AREA OF SURFACE HIGH  
PRESSURE ASSOCIATED WITH VERY DRY AIR WILL BUILD SOUTH INTO THE  
GREAT LAKES AND OHIO VALLEY. MAINLY CLEAR SKIES MONDAY NIGHT  
WILL GIVE WAY TO MOSTLY SUNNY SKIES ON TUESDAY. DESPITE THE  
SUNSHINE, TEMPERATURES WILL BE BELOW NORMAL FOR LATE MARCH AS  
COOL AIR WILL BE IN PLACE ACROSS THE REGION. AFTER LOWS IN THE  
20S, HIGHS WILL RANGE FROM THE LOWER 40S NORTH TO THE MID/UPPER  
40S SOUTH.  
 
FOR TUESDAY NIGHT INTO WEDNESDAY, ALTHOUGH THE CENTER OF THE  
SPRAWLING HIGH WILL MOVE EAST TO NEW ENGLAND THEN EVENTUALLY OFF  
THE NEW ENGLAND COAST, IT WILL STILL EXTEND WESTWARD INTO THE  
GREAT LAKES AND OHIO VALLEY. AFTER A COLD START IN THE 20S ON  
WEDNESDAY MORNING, TEMPERATURES WILL BEGIN TO MODERATE WITH  
PLENTY OF SUNSHINE WEDNESDAY. HIGHS WEDNESDAY WILL RANGE FROM  
NEAR 50 NORTH TO THE MID/UPPER 50S SOUTH.  
 
A MID LEVEL RIDGE AXIS WILL MOVE FROM THE PLAINS TO THE  
APPALACHIAN REGION WEDNESDAY NIGHT INTO THURSDAY. AT THE SAME  
TIME, SURFACE HIGH PRESSURE WILL CONTINUE TO MOVE SLOWLY OFF THE  
NEW ENGLAND COAST WHILE A FRONTAL SYSTEM BEINGS TO ORGANIZE  
ACROSS THE MID SECTION OF THE U.S. THIS PATTERN WILL ALLOW  
CLOUDS TO INCREASE ON THURSDAY. INCREASING SOUTHERLY FLOW  
BETWEEN THE TWO AFOREMENTIONED SYSTEMS WILL ALLOW TEMPERATURES  
TO WARM INTO THE 60S ALL LOCATIONS.  
 
FOR THURSDAY NIGHT INTO FRIDAY, MODELS CONTINUE TO DISAGREE ON  
THE SPEED AND EVOLUTION OF THE NEXT WEATHER SYSTEM TO AFFECT OUR  
REGION. GIVEN A DEVELOPING AMPLIFIED MID LEVEL FLOW PATTERN,  
WILL CONTINUE WITH A SLOW INCREASE OF CLOUDS AND CHANCES OF RAIN  
FROM WEST TO EAST THROUGH THIS PERIOD. AFTER LOWS IN THE 40S,  
HIGHS WILL ONCE AGAIN WARM INTO THE 60S FRIDAY IN A REGIME OF  
STRONG SOUTHERLY FLOW.  
 

 
   
AVIATION /12Z SATURDAY THROUGH WEDNESDAY/
 
 
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. SKIES HAVE  
CLEARED OUT, AND SHOULD REMAIN CLEAR WELL INTO THE DAY TODAY.  
NW WINDS WILL GENERALLY REMAIN BELOW 10 KNOTS, BEFORE BECOMING  
LIGHT AND VARIABLE DURING THE EVENING.  
 
HIGH AND MID LEVEL CLOUDS WILL BEGIN TO INCREASE TONIGHT, BUT  
PRECIPITATION APPEARS LIKELY TO HOLD OFF UNTIL LATER ON SUNDAY.  
WINDS ON SUNDAY WILL PICK UP FROM THE SOUTH / SSW, INCREASING TO  
AROUND 10 KNOTS.  
 
OUTLOOK...MVFR CONDITIONS ARE POSSIBLE ON SUNDAY NIGHT AND  
MONDAY.  
 

 
   
ILN WATCHES/WARNINGS/ADVISORIES
 
 
OH...NONE.  
KY...NONE.  
IN...NONE.  
 

 
 

 
SYNOPSIS...HATZOS  
NEAR TERM...HATZOS  
SHORT TERM...HATZOS  
LONG TERM...HICKMAN  
AVIATION...HATZOS  
 
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