953  
FXUS63 KLMK 221118  
AFDLMK  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LOUISVILLE KY  
618 AM EST MON JAN 22 2018  
   
..UPDATED AVIATION DISCUSSION
 
 
   
SHORT TERM
 
(TODAY THROUGH TUESDAY)  
ISSUED AT 255 AM EST MON JAN 22 2018  
 
BOWLING BALL UPPER LOW MAKING ITS WAY ACROSS KANSAS WILL CATCH UP TO  
ITS SFC REFLECTION LATER TODAY, AND THE SYSTEM WILL BECOME  
VERTICALLY STACKED OVER NW MISSOURI THIS EVENING BEFORE HEADING ENE  
INTO THE GREAT LAKES TONIGHT. WARM CONVEYOR BELT IS WELL ESTABLISHED  
FROM THE ARKLATEX UP INTO THE OZARKS, AND WILL TRANSLATE EASTWARD  
ACROSS THE OHIO VALLEY TODAY.  
 
HAVE GONE WITH CATEGORICAL POPS ACROSS THE REGION FOR TODAY, WITH  
THE BEST PRECIP CHANCES LATE THIS MORNING INTO EARLY AFTERNOON ALONG  
AND WEST OF I-65, AND LATER IN THE AFTERNOON FARTHER EAST INTO THE  
BLUEGRASS REGION AND ALONG THE CUMBERLAND ESCARPMENT. QPF FOR THIS  
EVENT IS FAIRLY MODEST, AVERAGING AROUND A QUARTER INCH. THUNDER  
REMAINS A LOW PROBABILITY, BUT THERE IS SOME WEAK ELEVATED  
INSTABILITY SO WE WILL INCLUDE A SLIGHT CHANCE FOR EMBEDDED THUNDER.  
NOT A HUGE DIFFERENCE IN PROBABILITIES WHEN ALL IS SAID AND DONE,  
BUT CONFIDENCE IS A BIT HIGHER SOUTH OF THE WESTERN KENTUCKY AND  
BLUEGRASS PARKWAYS.  
 
TEMPS WILL BE RELATIVELY FLAT THROUGH THE DAY TODAY, STAYING IN  
THE 50S TO LOWER 60S. BIGGER STORY WILL BE THE WIND LATER THIS  
AFTERNOON AND TONIGHT, AS THE WIND FIELDS ARE FAIRLY ROBUST.  
HOWEVER, WITH THE STRONGEST COLD ADVECTION ALOFT COMING DURING THE  
NIGHT, THAT WILL LIMIT THE GUSTINESS, BUT STILL COULD SEE GUSTS  
IN THE 30-40 MPH RANGE.  
 
NOT MUCH TEMP RECOVERY IS EXPECTED ON TUESDAY UNDER LINGERING UPPER  
TROFINESS BEHIND THE DEPARTING CYCLONE. MOST OF THE WRAPAROUND  
MOISTURE WILL STAY TO OUR NORTH, BUT HELD ON TO SLIGHT CHANCE POPS  
OVER THE BLUEGRASS REGION LATE IN THE DAY AS THE LOW-LEVEL FLOW  
TURNS MORE NORTHWESTERLY.  
   
LONG TERM
 
(TUESDAY NIGHT THROUGH SUNDAY)  
ISSUED AT 255 AM EST MON JAN 22 2018  
 
FAIRLY PROGRESSIVE PATTERN THROUGH THE MIDDLE OF THE WORK WEEK.  
INITIALLY DEEP CYCLONIC CURVATURE COULD KEEP SOME LINGERING PRECIP  
OVER THE BLUEGRASS INTO TUESDAY NIGHT, AND THAT COULD END AS  
FLURRIES IF IT PERSISTS LONG ENOUGH. HOWEVER LITTLE OR NO IMPACT IS  
EXPECTED.  
 
TEMPS NEAR SEASONAL NORMALS TUE NIGHT AND WED, WITH A WARMING TREND  
FOR THE LATTER HALF OF THE WEEK AS WE TREND INTO LOW-AMPLITUDE UPPER  
RIDGING, AND SOUTHWESTERLY LOW-LEVEL FLOW BEHIND A DEPARTING SFC  
HIGH.  
 
NEXT PRECIP CHANCE RAMPS UP FRI NIGHT AND STAYS WITH US FOR MUCH OF  
THE WEEKEND AS THE PATTERN AMPLIFIES ENOUGH TO GET A GOOD GULF  
MOISTURE TAP. TEMPS ARE MILD ENOUGH FOR THIS TO BE AN ALL-RAIN  
SYSTEM, BUT MOIST ADIABATIC PROFILES ARE TOO STABLE FOR ANY THUNDER  
THREAT. CAPPED PRECIP CHANCES IN THE LIKELY CATEGORY MAINLY TO  
ACCOUNT FOR TIMING UNCERTAINTIES. OTHERWISE RAIN AT SOME POINT  
DURING THE WEEKEND IS CLOSE TO A SLAM-DUNK. GFS AND ECMWF BOTH  
CURRENTLY SHOW A "CLEAN" FRONTAL PASSAGE, BUT OTHER RUNS HAVE SHOWN  
THE POTENTIAL FOR A SECONDARY SFC WAVE THAT COULD HANG THE FRONT UP  
ENOUGH FOR PRECIP TO PERSIST LONGER AND PERHAPS EVEN END AS SNOW.  
SUNDAY FORECAST WILL MENTION MIXED PRECIP, BUT IT'S A LOW-  
PROBABILITY FORECAST AT THIS POINT.  
 

 
   
AVIATION
 
(12Z TAF ISSUANCE)  
ISSUED AT 618 AM EST MON JAN 22 2018  
 
STRONG LOW-LEVEL SOUTHERLY WINDS IN PLACE THIS MORNING AHEAD OF A  
COLD FRONT AND ASSOCIATED RAIN BAND. MODERATE RAIN HAS SPREAD INTO  
FAR WESTERN KY/SOUTHEASTERN IL AND WILL REACH OWB/EVV WITHIN THE  
NEXT HOUR. FOR THE MOST PART, VFR CEILINGS ARE EXPECTED TODAY.  
HOWEVER, EXPECT A LOWERING WITH THE RAIN BAND AND ESPECIALLY RIGHT  
AFTER THE RAIN. ENHANCED LOW-LEVEL MOISTURE WILL LIKELY RESULT IN  
FUEL ALTERNATE AT HNB THIS AFTERNOON. DID INCLUDE A PERIOD OF HIGH-  
END MVFR AT BWG THIS AFTERNOON AS WELL. SDF COULD SEE TEMPORARY MVFR  
AROUND 21Z (AND LEX AROUND 00Z), BUT CONFIDENCE IN PREVAILING MVFR  
IS LOW AT THOSE TWO SITES.  
 
PEAK SOUTHERLY GUSTS TODAY SHOULD REACH 25-30 KTS, WITH WINDS  
VEERING SOUTHWESTERLY THIS EVENING. THE RAIN WON'T LAST ALL THAT  
LONG AT ANY ONE SITE, BUT A SECONDARY BAND OF SHOWERS MAY BE ABLE TO  
DEVELOP AFTER 21-22Z RIGHT ALONG THE SURFACE COLD FRONT. THIS BAND  
WOULD PUSH THROUGH LEX SHORTLY AFTER 00Z. WE'LL SEE A PERIOD OF  
CLEARING WHERE CLOUDS GO SCT LATE THIS EVENING AND TONIGHT AS A DRY  
SLOT WORKS IN BEHIND THE FRONT. BUT ADDITIONAL LOW CEILINGS WILL BE  
POSSIBLE TUESDAY MORNING AS CLOUDS WORK BACK IN FROM THE NORTHWEST.  
 

 
   
LMK WATCHES/WARNINGS/ADVISORIES
 
 
IN...NONE.  
KY...NONE.  

 
 

 
 
SHORT TERM...RAS  
LONG TERM...RAS  
AVIATION...EBW  
 
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