474  
FXUS61 KILN 230613  
AFDILN  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE WILMINGTON OH  
113 AM EST FRI FEB 23 2018  
   
SYNOPSIS
 
 
COPIOUS MOISTURE WILL COMBINE WITH MULTIPLE WEATHER  
DISTURBANCES RIDING ALONG A SLOW MOVING FRONT TO PRODUCE HEAVY  
RAINFALL AND FLOODING TONIGHT THROUGH SATURDAY. DRY WEATHER IS  
EXPECTED WITH THE ARRIVAL OF HIGH PRESSURE SUNDAY THROUGH  
TUESDAY. ABOVE NORMAL TEMPERATURES ARE FORECAST TO PERSIST  
THROUGH THE PERIOD.  
 

 
   
NEAR TERM /THROUGH TODAY/
 
 
OUR REGION REMAINS IN A RELATIVE PRECIPITATION LULL THIS  
EVENING. HAVE ADDED AREAS OF DRIZZLE OCCURRING IN SATURATED  
SHALLOW MOISTURE, A PRECURSOR TO RAIN ARRIVING LATER TONIGHT.  
 
AN EMBEDDED S/WV IN A VERY MOIST SOUTHWEST FLOW ALOFT WILL  
INTERACT WITH A NORTHWARD MOVING WARM FRONT OVERNIGHT. A DECENT  
LLJ WILL DEVELOP TO OUR SOUTHWEST, AND THIS WILL IMPINGE ON THE  
WARM FRONT, PRODUCING SUBSTANTIAL MOISTURE CONVERGENCE. AS A  
RESULT, SHOWERS WILL DEVELOP AND INCREASE FROM OUR SOUTHWEST  
LATE. MODELS ARE ALSO SHOWING AT LEAST ELEVATED INSTABILITY, SO  
A CHANCE OF THUNDERSTORMS IS ALSO MENTIONED. WITH PWATS FORECAST  
TO APPROACH 1.50 INCHES (WHICH IS TYPICAL OF JULY AND ABOUT 3  
SIGMA VALUES ABOVE CLIMO) THE POTENTIAL FOR MODERATE TO HEAVY  
RAINFALL EXISTS. POINTS ALONG AND SOUTH OF THE OHIO RIVER HAVE  
ALREADY RECEIVED 1 TO 3 INCHES OF RAIN TODAY. THUS, ANY  
ADDITIONAL RAINFALL WILL LIKELY GO DIRECTLY INTO RUNOFF DUE TO  
SATURATED SOILS, RESULTING IN CONTINUED OR RENEWED FLOODING.  
BASED ON MODEL QPF FOOT PRINTS, THE THREAT FOR MODERATE TO HEAVY  
RAIN MAY AFFECT LOCATIONS ALONG THE I-70 CORRIDOR AS WELL. THIS  
RAINFALL COMBINED WITH FUTURE RAINFALL THIS WEEKEND HAS  
PROMPTED AN EXPANSION OF THE FLOOD WATCH IN THESE LOCATIONS.  
TEMPERATURES WILL NOT CHANGE THAT MUCH THIS EVENING, BUT THEN  
RISE, ESPECIALLY SOUTH, AS THE WARM FRONT LIFTS NORTH.  
 

 
   
SHORT TERM /TONIGHT THROUGH 6 PM SATURDAY/
 
 
SHOWERS AND EMBEDDED THUNDERSTORMS SHOULD BE ONGOING OVER MUCH  
OF THE REGION FRIDAY MORNING. A COLD FRONT IS FORECAST TO MOVE  
INTO THE REGION FROM THE WEST DURING THE DAY. THIS BOUNDARY WILL  
INTERSECT THE NORTHEAST ADVANCING WARM FRONT. PRECIPITATION  
SHOULD TAPER OFF BEHIND COLD FRONTAL PASSAGE WHILE CONTINUING  
NEAR THE COLD FRONT AND WARM FRONTS. ADDITIONAL MODERATE TO  
HEAVY RAINFALL IS EXPECTED. HIGH TEMPERATURES WILL RANGE FROM  
THE MID 50S NORTHWEST TO THE LOWER 70S SOUTHEAST.  
 
FOR FRIDAY NIGHT, THE COLD FRONT WILL SLIP SOUTH OF THE OHIO  
RIVER WHERE IT WILL EVENTUALLY STALL. THERE SHOULD BE A LULL IN  
THE PRECIPITATION THREAT ACROSS THE NORTH, WITH CHANCES  
CONTINUING ALONG AND SOUTH OF THE OHIO RIVER. THE COLD FRONTAL  
BOUNDARY WILL BEGIN MOVING BACK NORTHWARD AS A WARM FRONT LATE  
AS MORE S/WV ENERGY IN THE MIDLEVEL RIPPLES ONCE AGAIN INTO THE  
REGION. THUS, HAVE POPS RAMPING UP LATE. LOWS WILL RANGE FROM  
THE LOWER 40S NORTHWEST TO THE UPPER 50S SOUTHEAST.  
 

 
   
LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/
 
 
ANOMALOUSLY STRONG SUB TROPICAL RIDGE OVER THE SOUTHEAST WITH A  
MOIST SOUTHWESTERLY FLOW FOCUSED INTO THE OHIO VALLEY TO BEGIN THE  
LONG TERM FORECAST PERIOD. AN ACTIVE WET WEATHER PATTERN TO CONTINUE  
INTO SUNDAY LEADING TO A CONTINUED FLOOD THREAT.  
 
MID LEVEL SHORTWAVE AND DEEPENING SURFACE LOW TO EJECT NORTHEAST  
FROM THE CENTRAL PLAINS INTO THE GREAT LAKES SATURDAY NIGHT/SUNDAY.  
STRONG LOW LEVEL JET OF 70-80 KTS WILL PROVIDE ANOMALOUS MOISTURE  
INTO THE AREA AND MARGINAL INSTBY ACROSS THE AREA. MOISTURE WILL  
POOL AHEAD OF A FRONT MOVING INTO THE AREA LATE SATURDAY NIGHT/EARLY  
SUNDAY WITH PRECIPITABLE WATER VALUES APPROACHING 1.5 INCHES, WHICH  
IS A RECORD VALUE FOR THIS TIME OF YEAR.  
 
WILL CONTINUE WITH CATEGORICAL POPS SATURDAY NIGHT. HIGH SHEAR LOW  
CAPE SEVERE WEATHER SETUP SHOWING A SIGNAL WITH SHERB 0-3KM  
PARAMETER SATURDAY NIGHT. IN TIGHTENING PRESSURE GRADIENT WILL HAVE  
WINDS GUST UP TO 35 MPH.  
 
WITH THE FRONT EXPECTED TO SWEEP EAST THROUGH THE AREA EARLY SUNDAY  
A DRYING TREND TO DEVELOP. SURFACE HIGH PRESSURE WILL BUILD ACROSS  
THE GREAT LAKES OFFERING DRY WEATHER FROM SUNDAY INTO THE MIDDLE OF  
NEXT WEEK. EXPECT EARLY HIGHS ON SUNDAY WITH TEMPERATURES FALLING  
INTO THE 40S AND LOWER 50S IN THE AFTERNOON.  
 
TEMPERATURES TO TURN COOLER BUT STILL ABOVE NORMAL WITH HIGHS MONDAY  
FROM THE UPPER 40S NORTH TO THE MID 50S SOUTH. TEMPERATURES TUESDAY  
LOOK TO BE AROUND 10 DEGREES ABOVE NORMAL, WITH HIGHS FROM THE LOWER  
50S NORTH TO THE UPPER 50S SOUTH.  
 
MODEL SOLUTION DIFFERENCES DEVELOP AT MID WEEK REGARDING HOW FAST  
MOISTURE RETURNS ON THE BACKSIDE OF RETREATING SURFACE HIGH  
PRESSURE. WILL LIMIT POPS LOW CHANCE WEDNESDAY AFTERNOON SOUTH AND  
THEN ACROSS THE ENTIRE FA THURSDAY. MILD TEMPERATURES TO CONTINUE  
WITH HIGHS IN THE 50S WEDNESDAY AND THURSDAY.  
 

 
   
AVIATION /06Z FRIDAY THROUGH TUESDAY/
 
 
IFR CIGS/VSBYS WILL BE FOUND OVER MUCH OF THE REGION FOR THE  
NEXT FEW HOURS. A SHOT OF RAIN WILL WORK IN FROM THE SOUTHWEST  
BEFORE DAYBREAK AND LAST FOR A FEW HOURS. THIS IS ASSOCIATED  
WITH THE PASSAGE OF A LOW LEVEL JET TOWARDS DAYBREAK. A BRIEF  
INCLUSION OF LLWS MAY BE NECESSARY AT CVG/LUK AS IT PASSES BUT  
THE HIGHEST WIND SPEEDS WILL BE ABOVE THE 2KFT THRESHOLD.  
LIKEWISE, GIVEN THE STRONG DYNAMICS PRESENT THERE MAY BE  
SIGNIFICANT SLANT-WISE CONVECTION TO PRODUCE THUNDER. WILL BE  
MONITORING BOTH OF THESE POTENTIALS UPSTREAM AND AMEND IF THEY  
PRESENT THEMSELVES. RAIN WILL BE AN EARLY SHOT AND SEE SOME  
PASSING SHOWERS THROUGH THE EARLY AFTERNOON. FOCUS FOR SHOWERS  
THEN SHIFTS SOUTHEAST AND AWAY FROM THE TAF SITES, BUT THE  
PROXIMITY OF THE AXIS OF GOOD RAINFALL IS TOO CLOSE TO NOT  
INCLUDE VCSH FOR THE BULK OF THE DAYLIGHT HOURS TODAY.  
 
LATER IN THE EVENING, MODELS ARE HINTING THAT CIGS MAY IMPROVE  
IF THE LOWER THOUSAND FEET COULD LOSE ITS BROKEN CHARACTERISTIC.  
A LARGE DRY AREA NOTED ABOVE 1KFT WOULD BRING VFR CONDITIONS IF  
THE LOW STRATUS SCATTERS OUT.  
 
CVG SHOULD SEE A RETURN TO IFR LATE IN THEIR 30 HOUR TAF AS THE  
NEXT BATCH OF RAIN OVERSPREADS THE REGION IN THE PREDAWN HOURS  
SATURDAY.  
 
OUTLOOK...MVFR/IFR CEILINGS AND VISIBILITIES ARE LIKELY INTO  
SATURDAY NIGHT. MVFR CEILINGS MAY LINGER SUNDAY.  
 

 
   
ILN WATCHES/WARNINGS/ADVISORIES
 
 
OH...FLOOD WATCH THROUGH SUNDAY MORNING FOR OHZ053>056-060>065-  
070>074-077>082-088.  
KY...FLOOD WATCH THROUGH SUNDAY MORNING FOR KYZ089>100.  
IN...FLOOD WATCH THROUGH SUNDAY MORNING FOR INZ050-058-059-066-  
073>075-080.  
 

 
 

 
SYNOPSIS...CONIGLIO  
NEAR TERM...CONIGLIO/HICKMAN  
SHORT TERM...HICKMAN  
LONG TERM...AR  
AVIATION...FRANKS  
 
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