507 FXUS63 KJKL 281826 AAC AFDJKL AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE JACKSON KY 226 PM EDT FRI MAR 28 2014 .UPDATE... ISSUED AT 210 PM EDT FRI MAR 28 2014 GRIDS WERE FRESHENED UP BASED ON THE LATEST OBSERVATION TRENDS. SHOWER ACTIVITY IS NEXT TO NIL ACROSS THE REGION IN ADVANCE OF THE COLD FRONT. THIS IS LIKELY DUE TO SOME MID LEVEL CAPPING AS SHORTWAVE MID LEVEL RIDGING BETWEEN THE DEPARTING SHORTWAVE AND THE NEXT SYSTEMS WORKS ACROSS THE OH VALLEY REGION. SHOWER ACTIVITY THIS AFTERNOON SHOULD BE MINIMAL...IF ANY AT ALL ACROSS THE REGION. AT THIS TIME...WE PLAN TO LET THE SLIGHT CHANCE POPS RIDE SINCE THE NAM AND GFS AS WELL AS THE HRRR STILL HAVE SOME CONVECTION LATER THIS AFTERNON AND INTO THE EVENING. UPDATE ISSUED AT 1120 AM EDT FRI MAR 28 2014 THE PREFRONTAL CONVECTION HAS EXITED TO THE SOUTH AND EAST...ALTHOUGH THE COLD FRONT IS ONLY MAKING SLOW SOUTHEAST PROGRESS AND IS NEAR OR JUST WEST OF THE INTERSTATE 65 CORRIDOR. A MID LEVEL SHORTWAVE OVER THE GREAT LAKES REGION IS EXITING TO THE NORTH AND EAST OF THE AREA. A RELATIVE LULL IN ACTIVITY IS ANTICIPATED BETWEEN THIS DEPARTING SHORTWAVE AND THE NEXT WAVE TO APPROACH THE AREA TONIGHT. THUS...POPS HAVE BEEN LOWERED TO SLIGHT CHANCE FOR THE REMAINDER OF THE DAY INTO THE EVENING. ALSO...HOURLY SKY...TEMPS AND DEWPOINTS HAVE BEEN FINE TUNED TO REFLECT RECENT OBSERVATIONS AS WELL AS SATELLITE AND RADAR IMAGERY. UPDATE ISSUED AT 800 AM EDT FRI MAR 28 2014 THE THUNDERSTORMS WITH THE COLD FRONT ARE FADING OUT NOW SO HAVE BACKED OFF OF THEM TO JUST AN ISOLATED MENTION IN THE GRIDS. HAVE TIMED THE CORE OF THE PCPN THROUGH THE AREA FROM WEST TO EAST FROM 12 TO 15Z. ALSO...FINE TUNED TEMPS AND DEWPOINTS THROUGH THE NEXT SEVERAL HOURS WITH THIS UPDATE PER THE LATEST OBS AND TRENDS. THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 335 AM EDT FRI MAR 28 2014 06Z SFC ANALYSIS SHOWS A DEEP AREA OF LOW PRESSURE MOVING THROUGH THE GREAT LAKES WITH A SHARP COLD FRONT ENTERING THE OHIO VALLEY. THIS BOUNDARY IS SHOWING UP WELL ON RADAR AS A THIN LINE OF SHOWERS AND THUNDERSTORMS DROPPING SOUTHEAST TOWARD KENTUCKY. SCATTERED TO NUMEROUS SHOWERS ARE FOUND OUT AHEAD OF THIS LINE THROUGH CENTRAL EASTERN KENTUCKY. THIS ADVANCE CONVECTION IS WORKING TO MOISTEN UP THE VERY DRY AIR OVER EAST KENTUCKY AND THUS FAR NOT AMOUNTING TO TOO MUCH ACCUMULATION. HAVE TIMED THE FRONT INTO EAST KENTUCKY AROUND 12Z AND THROUGH BY 15Z...HIGHLIGHTING THIS TIME FRAME WITH THE HIGHEST POPS AND BEST CHANCE FOR THUNDER. IN THE MEANTIME...GUSTY SHOWERS AND SPRINKLES WILL CONTINUE OVER THE CWA. AHEAD OF THE FRONT THE TEMPERATURES ARE REMAINING QUITE MILD WITH READINGS GENERALLY IN THE LOW TO MID 50S. DEWPOINTS VARY FROM THE LOWER 40S IN THE WEST TO AROUND 30 IN THE FAR EAST. OUTSIDE OF THE HIGHER GUSTS IN SHOWERS... WINDS ARE RUNNING FROM THE SOUTH TO SOUTHWEST AT 10 TO 15 MPH WITH GUSTS TO 25 MPH. HIGHER SUSTAINED SPEEDS AND GUSTS TO 35 MPH ARE STILL POSSIBLE WITH THE SHOWERS...PARTICULARLY OVER THE NORTHERN AND WESTERN PARTS OF THE CWA. THE MODELS ARE IN DECENT AGREEMENT ALOFT WITH THE SHALLOW TROUGH PASSING THROUGH THE GREAT LAKES THIS MORNING. THIS IS FOLLOWED BY SOUTHWEST FLOW AND AN AMPLIFYING TROUGH OVER THE CENTRAL PLAINS INTO TONIGHT. THIS NEXT TROUGH IMPRESSIVELY DEEPENS AS IT MOVES INTO THE AREA AND RIGHT OVER KENTUCKY ON SATURDAY. THIS FEATURE NEARLY CLOSES OFF AND IS SURPRISINGLY SIMILAR IN THE MODELS AT 00Z SUNDAY WITH THE GEM AND GFS THE STRONGEST. THE ECMWF AND NAM ARE A BIT WEAKER...BUT THE PATTERNS AND TIMING ALL MATCH UP WELL. GIVEN THIS...HAVE GONE WITH A GENERAL MODEL BLEND AND FOLLOW SPECIFICS FROM THE NAM12 AND GFS. SENSIBLE WEATHER WILL FEATURE A VERY ACTIVE AND CHANGEABLE SHORT TERM PORTION OF THE FORECAST. FOR STARTERS...SHOWERS AND A POSSIBLE THUNDERSTORM...WILL CROSS THROUGH ALL OF EAST KENTUCKY THIS MORNING AS A COLD FRONT MOVES THROUGH. LOOK FOR CLOUDY SKIES TO REMAIN ALONG WITH SOME LINGERING SHOWERS FOR THE AFTERNOON...ESPECIALLY OVER THE SOUTHEAST. THIS FRONT WILL SETTLE JUST SOUTH OF THE AREA THIS EVENING AND QUICKLY REACTIVATE OVER THE WEST BY MIDNIGHT. THIS NEXT WAVE... DRIVEN BY THE APPROACHING AND STRENGTHENING MID LEVEL TROUGH...WILL CONSOLIDATE OVER THE TENNESSEE VALLEY BY EARLY SATURDAY MORNING AND RETURN SHOWERS AND POSSIBLE THUNDERSTORMS TO EAST KENTUCKY. THE CENTER OF THIS LOW WILL PASS THROUGH FAR SOUTHEAST KENTUCKY DURING THE DAY AND START TO PULL IN COLDER AIR FROM THE NORTH. THERE IS STRONG MODEL SUPPORT FOR THE COLUMN OF AIR COOLING ENOUGH BY LATE AFTERNOON IN THE NORTHWEST PARTS OF THE CWA TO RESULT IN A CHANGEOVER TO SNOW. SFC TEMPERATURES WILL STAY UP WELL ABOVE FREEZING THROUGH 00Z SUNDAY SO ANY ACCUMULATIONS WILL HOLD OFF UNTIL LATER THAT NIGHT. FOR TEMPERATURES...WINDS...AND DEW POINTS USED THE BC/CONSSHORT AS A STARTING POINT THROUGH THE EARLY OVERNIGHT HOURS OF SATURDAY. AFTER THAT USED AN ADJUSTED VERSION OF THE RAW NAM FOR TEMPS AND THE BC/CONSALL FOR TD AND WINDS. AS FOR POPS...ENDED UP RATHER WET AND IN LINE WITH THE MOS GUIDANCE. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 330 AM EDT FRI MAR 28 2014 THE EXTENDED FORECAST PERIOD BEGINS ON SATURDAY NIGHT WITH A PROGRESSIVE AND ACTIVE PATTERN IN PLACE AS A STRONG SHORTWAVE IS MOVING THROUGH THE OH AND TN VALLEY AT THIS TIME AND MOVES UP THE EAST COAST BY SUNDAY NIGHT. AFTER THAT...MID LEVEL RIDGING CAUSES A FAST MOVING SHORT WAVE TO MOVE NORTHEAST INTO THE GREAT LAKES REGION AND INTO NEW ENGLAND BY TUESDAY. AFTER THIS...A BROAD CLOSED LOW CROSSES THE FRONT RANGE AND INTO THE CENTRAL PLAINS BY TUESDAY NIGHT AND INTO WEDNESDAY. THIS WAVE DEEPENS AS IT THEN MOVES INTO THE MS RIVER VALLEY ON THURSDAY. THE GFS AND EURO SEEM TO BE IN DECENT AGREEMENT WITH THIS PATTERN...ESPECIALLY WITH THE LOW TOWARDS THE END OF THE EXTENDED WHICH COULD BE A SIGNIFICANT EVENT. IN THE LOWER LEVELS FOR SATURDAY NIGHT...THE COLDER AIR FILTERING IN BEHIND THE FRONT THAT PASSED THROUGH ON SATURDAY WILL MAKE INTO THE AREA FAST ENOUGH FOR RAIN TO CHANGE TO SNOW. IN FACT...WITH THE SMALL LAYER OF DRIER AIR AT THE SURFACE FOR SOME WET BULBING...THE COLDER AIR NOT FAR OFF THE SURFACE...AND THE CONVECTIVE PROPERTIES OF THE SHOWERS...WILL NOT BE SURPRISED TO SEE SNOW AT 35 DEGREES AT THE SURFACE. WITH THE DEPTH OF THE MOIST LAYER AND THE OMEGA AVAILABLE...HAVE ALSO PUT IN SOME ACCUMULATING SNOW IN THE FORECAST WITH MAINLY THE BLUE GRASS AND THE HIGHER TERRAIN IN THE NORTH AND EAST. THE FRONT MOVING THROUGH ON TUESDAY LOOKS TO DRY OUT AS IT APPROACHES THE AREA. THE BEST DYNAMICS TAKE A FARTHER TRACK NORTH AND HAVE LEFT SLIGHT CHANCE POPS NORTH OF THE FORECAST AREA. HOWEVER...WILL NOT BE SURPRISED TO SEE SOME SPRINKLES POP UP TUESDAY AFTERNOON. ANY HINT THAT THE DEVELOPING SHOWERS WILL NOT SHEAR OUT AND SOME ADDITIONAL MOISTURE AVAILABLE...THE CHANCE IS THERE FOR SOME SHOWERS AND AN ISOLATED THUNDERSTORM. THERE IS A GOOD BIT OF SURFACE INSTABILITY TUESDAY AFTERNOON. FOR NOW...WILL KEEP THIS PERIOD DRY. WITH MOST LIKELY A DRY PERIOD CONTINUING INTO WEDNESDAY...THE SET UP TOWARDS THE END OF THE EXTENDED WILL CHANGE THIS DRY PATTERN. SURFACE HIGH PRESSURE SETS UP OVER THE SOUTHEAST AND PROVIDING WARM MOIST SOUTHERLY FLOW INTO THE OH VALLEY AHEAD OF THE NEXT APPROACHING POTENT SYSTEM WILL BRING SHOWERS AND THUNDERSTORMS INTO THE AREA LATE WEDNESDAY AND THROUGH THE REST OF THE EXTENDED. THIS SET UP WILL BE ONE TO WATCH FOR HOW IT DEVELOPS. A LOT CAN CHANGE IN THE MODELS BETWEEN NOW AND THEN BUT THE POTENTIAL FOR SEVERE WEATHER IS PRESENT WITH THIS SET UP. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 210 PM EDT FRI MAR 28 2014 A COLD FRONT HAS BEGUN TO STALL ACROSS THE OH VALLEY REGION AS THE FIRST SFC LOW AND ASSOCIATED MID LEVEL DISTURBANCE DEPART AND SFC LOW PRESSURE BEGINS TO ORGANIZE OVER THE SOUTHERN PLAINS. THIS NEXT SFC LOW WILL TRACK ACROSS THE AREA LATE TONIGHT AND INTO SAT. SOME LOCATIONS SHOULD IMPROVE TO VFR FOR A WHILE OVER THE FIRST 6 TO 9 HOURS OF THE PERIOD IN BETWEEN SYSTEMS. CLOUDS WILL REMAIN...JUST ABOVE THE MVFR VFR BREAK IN LOCATIONS THAT DO IMPROVE TO VFR. THIS NEXT LOW WILL BRING RENEWED CHANCES FOR SHOWERS AND POSSIBLY ISOLATED TSRA AS WELL AS ANOTHER LOWERING OF CONDITIONS BACK TO MVFR BETWEEN 8Z AND 14Z. THIS WILL BE AFTER && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JP SHORT TERM...GREIF LONG TERM...SHALLENBERGER AVIATION...JP