829  
FXUS63 KJKL 260840  
AFDJKL  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE JACKSON KY  
440 AM EDT SUN MAR 26 2017  
   
SHORT TERM
 
(TODAY THROUGH MONDAY)  
ISSUED AT 439 AM EDT SUN MAR 26 2017  
 
A WEAKENING STACKED LOW PRESSURE SYSTEM IS CENTERED IN THE  
VICINITY OF QUINCY, IL AND BURLINGTON, IA EARLY THIS MORNING. THE  
MID/UPPER LEVEL PORTION OF THE SYSTEM HAS A TROUGH AXIS EXTENDING  
SOUTHEAST TO THE GULF OF MEXICO. AS THE TROUGH MOVES NORTHEAST,  
IT IS INTERACTING WITH A MOIST FLOW OF AIR OFF THE GULF, RESULTING  
IN A LARGE AREA OF SHOWERS. THE LEADING EDGE OF SHOWERS IS OVER  
THE SOUTHWEST PART OF THE JKL FORECAST AREA EARLY THIS MORNING,  
HEADING EAST NORTHEAST. THE AREA OF SHOWERS WILL MAKE ITS WAY  
ACROSS THE REST OF THE FORECAST AREA THIS MORNING, AND THE BACK  
EDGE WILL EXIT INTO WV AROUND MID DAY.  
 
THERE IS NO CHANGE IN SURFACE AIR MASS TAKING PLACE WITH THIS  
ROUND OF PRECIP. HOWEVER, THERE ARE COLDER TEMPERATURES ALOFT  
BEHIND THE LEADING BAND OF PRECIP. THIS HAS RESULTED IN SCATTERED  
SHOWERS AND A FEW THUNDERSTORMS DURING THE NIGHT OVER WESTERN KY  
AND WEST TN. AS THE REGIME SHIFTS EASTWARD TODAY, FORECAST  
SOUNDINGS SHOW INSTABILITY DEVELOPING TO SUPPORT SHOWERS AND  
THUNDERSTORMS HERE. UNCERTAINTY EXISTS IN THE EXTENT OF COVERAGE.  
WHILE EVERYONE SHOULD SEE RAIN OUT OF THE LEADING BAND OF PRECIP  
COMING THROUGH EARLY, THAT MAY NOT BE THE CASE IN THE AFTERNOON.  
WHATEVER SHOWERS/STORMS DO OCCUR WILL BE ON THE DECLINE AND  
MOVING OUT TO THE NORTHEAST WITH THE UPPER LEVEL SYSTEM TONIGHT.  
 
ANOTHER SURFACE LOW PRESSURE SYSTEM AND AN ASSOCIATED WAVE ALOFT  
WILL MOVE NORTHEAST TOWARD THE OHIO VALLEY ON MONDAY. THIS WILL  
BRING WITH IT ANOTHER INCREASE IN SHOWERS AND THUNDERSTORMS, AIDED  
BY DIURNAL DESTABILIZATION. THE PEAK IN ACTIVITY WILL LIKELY COME  
ON MONDAY EVENING, BEYOND THE SHORT TERM PERIOD.  
 
   
LONG TERM
 
(MONDAY NIGHT THROUGH SATURDAY)  
ISSUED AT 439 AM EDT SUN MAR 26 2017  
 
ONE OF A STRING OF UPPER LEVEL WAVES THAT IS MOVING INTO THE FOUR  
CORNERS REGION THIS MORNING BASED ON THE 00Z 500MB ANALYSIS WILL  
BRING A DECENT SHOT OF SHOWERS AND THUNDERSTORMS FOR THE BEGINNING  
OF THE PERIOD MONDAY NIGHT. THIS WAVE WILL INDUCE A SURFACE LOW  
ACROSS THE CENTRAL PLAINS BY TONIGHT AND EJECT INTO THE OHIO VALLEY  
MONDAY NIGHT. MODELS SEEM TO BE HANDLING THIS WELL AND FEEL MORE  
CONFIDENT IN THIS VERSUS MUCH OF THE REST OF THE LONG TERM PORTION  
OF THE FORECAST. TUESDAY THE SYSTEM WILL CONTINUE TO PROGRESS EAST  
AND TRIM POPS THROUGH THE DAY FROM WEST TO EAST. MODELS ARE IN  
DECENT AGREEMENT WITH THE DRYING PERIOD FROM TUESDAY NIGHT INTO  
WEDNESDAY NIGHT. WHILE THERE IS SOME AMPLITUDE DIFFERENCES WITH THE  
UPPER LEVEL RIDGE AND HEIGHT RISES THINK THERE IS ENOUGH TO KEEP THE  
REGION DRY. THIS ALSO COINCIDES WITH THE NAEFS RELATIVE MIN IN PWATS.  
 
BEYOND THIS MODELS BECOME QUITE CONVOLUTED AND BEGIN TO DIVERGE IN  
THEIR RESPECTIVE SOLUTIONS. THE 00Z GFS WANTS TO BRING A MORE  
POSITIVELY TO NEUTRAL TILTED CLOSED LOW EAST OUT OF THE PLAINS BY  
THURSDAY NIGHT AND THE 00Z ECMWF BRING A MORE NEUTRALLY TO SLIGHTLY  
NEGATIVELY TILTED TROUGH WITH MORE OF A NORTHERN STREAM INFLUENCE BY  
THE SAME TIME FRAME. THIS SEEMS TO BE A PHASING ISSUE AND THESE TWO  
SOLUTIONS WILL HAVE IMPLICATIONS ON THE SURFACE FEATURES AS WELL.  
THERE ALSO REMAINS A REASONABLE AMOUNT OF SPREAD IN THE GFS ENSEMBLE  
MEAN IN REGARDS TO THE UPPER LEVEL FEATURE AND SPREAD IN THE  
INDIVIDUAL MEMBERS WITH REGARDS TO LOW PLACEMENT HINTS PREVIOUS  
STATEMENT. EVEN GIVEN SOME UNCERTAINTY THE FACT THAT BOTH SOLUTIONS  
WOULD BRING A DECENT SHOT OF SHOWERS AND PERHAPS SOME THUNDERSTORMS  
WENT WITH LIKELY POPS FROM WEST TO EAST FROM LATE THURSDAY INTO  
FRIDAY EVENING. THE BLEND WANTED TO GO CAT POPS BUT FELT LIKE  
UNCERTAINTY WOULD BE TOO MUCH FOR THAT BULLISH OF POPS. THIS SYSTEM  
PEGGED TO MOVE INTO THE MID ATLANTIC AND THEREFORE A PERIOD OF  
DRYING WILL RESUME SATURDAY. OVERALL THE PERIOD WILL BE MET WITH  
WELL ABOVE TO ABOVE AVERAGE TEMPERATURES.  
 

 
   
AVIATION
 
(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)  
ISSUED AT 243 AM EDT SUN MAR 26 2017  
 
VFR CONDITIONS PREVAILED ACROSS THE JKL FORECAST AREA AT THE  
START OF THE PERIOD. AN AREA OF RAIN EXTENDED FROM SOUTHERN IN AND  
CENTRAL KY SOUTH TOWARD THE GULF COAST. WHILE INDIVIDUAL  
CELLS/ELEMENTS WERE MOVING NORTHWARD, THE ENTIRE AREA WAS SLOWLY  
SHIFTING EASTWARD. THIS LEADING EDGE OF PRECIP WAS CURRENTLY  
ARRIVING AROUND KEKQ, AND WILL CROSS THE JKL FORECAST AREA FROM  
WEST TO EAST THIS MORNING. A PERIOD OF MVFR CAN BE EXPECTED WITH  
THE PRECIP IN MOST AREAS. IT WILL TAPER OFF TO SCATTERED SHOWERS  
FROM WEST TO EAST BETWEEN ABOUT 12Z AND 17Z. A RESURGENCE OF  
PRECIP MAY OCCUR WITH HEATING/DESTABILIZATION THIS AFTERNOON, WITH  
SOME THUNDERSTORMS ALSO POSSIBLE. POOR CONDITIONS CAN BRIEFLY BE  
EXPECTED IN ANY SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND  
EVENING, BUT OUTSIDE OF THE PRECIP VFR SHOULD PREVAIL. THE SHOWERS  
AND THUNDERSTORMS WILL DIMINISH TONIGHT.  
 
WINDS WILL PICK UP FROM THE SOUTH TO SOUTHWEST DURING THE DAY,  
WITH GUSTS AROUND 20 KT.  
 

 
   
JKL WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  

 
 

 
 
SHORT TERM...HAL  
LONG TERM...DJ  
AVIATION...HAL  
 
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