Area Forecast Discussion
Issued by NWS Jackson, KY

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KJKL 260554 AAA
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON KY
154 AM EDT THU MAR 26 2015

.UPDATE...
ISSUED AT 154 AM EDT THU MAR 26 2015

HAVE UPDATED TO ADJUST DOWN THE FORECAST LOWS IN THE
VALLEYS...WITH THE COOLEST SPOTS HAVING ALREADY MADE IT DOWN INTO
THE UPPER 40S. OTHERWISE...WILL AWAIT WEAKENING CONVECTION OUT
WEST TOWARDS DAWN.

UPDATE ISSUED AT 1117 PM EDT WED MAR 25 2015

HAVE MODIFIED POPS AND WEATHER FOR THE FIRST SEVERAL PERIODS BASED
ON LATEST MODEL DATA. ALLOWED FOR A POSSIBILITY OF
SHOWERS/THUNDERSTORMS AHEAD OF THE COLD FRONT...BUT HIT THE POPS
HARDEST WITH RAIN BEHIND THE FRONT ON THURSDAY INTO THURSDAY
NIGHT. SOUNDINGS WERE NOT VERY SUPPORTIVE OF SNOW UNTIL LATE
FRIDAY OR FRIDAY NIGHT. PRECIP AND MOISTURE ALOFT AT -10C LOOKS
LIKE IT WILL PULL OUT BEFORE SURFACE TEMPS ARE COLD ENOUGH FOR
SNOW ON THURSDAY NIGHT.

UPDATE ISSUED AT 650 PM EDT WED MAR 25 2015

UPDATED TO BLEND LATE DAY OBS INTO THE FORECAST. ALSO ADJUSTED
TIMING/RATE OF TEMPERATURE CHANGE WITH FROPA ON THURSDAY BASED ON
LATEST MODEL RUNS...BUT WITH LITTLE OVERALL CHANGE TO MIN OR MAX
TEMPS.

&&

.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 318 PM EDT WED MAR 25 2015

AFTER THE PASSAGE OF A WARM FRONT ACROSS THE CWA THIS
MORNING...WINDS HAVE OBTAINED A MORE SW HEADING WITH DECENT MIXING
RESULTING IN GUSTS BETWEEN 15 AND 25KTS. MEANWHILE...THE
APPROACHING COLD FRONT HAS STALLED OUT JUST NORTH OF THE OHIO
RIVER...CONNECTED TO ANOTHER LOW PRESSURE SYSTEM CURRENTLY SITTING
OVER NORTHERN TX. THIS SURFACE LOW IS EXPECTED TO SHIFT TO THE NE
THROUGH THIS EVENING...FOLLOWING THE OHIO RIVER AND KEEPING THE
COLD FRONT NEARLY STATIONARY. THIS WILL BE IN CONJUNCTION WITH A
STRONG UPPER LEVEL LONGWAVE TROUGH DEVELOPING OVER THE CENTRAL
CONUS AROUND THIS SAME TIME. IT WON/T BE UNTIL AFTER MIDNIGHT THAT
THE LONGWAVE PATTERN WILL PUSH THE SURFACE LOW PRESSURE SYSTEM
AND COLD FRONT FAR ENOUGH EAST TO AFFECT THE CWA.

MOST OF THE MOISTURE WITH THIS SYSTEM WILL BE LOCATED ALONG AND
BEHIND THE FRONTAL PASSAGE...ENCOMPASSING MUCH OF EASTERN KY AFTER
6Z AND CONTINUING THROUGH THURSDAY NIGHT. STILL EXPECTING THE BEST
INSTABILITY AND HEAVIEST RAIN ALONG THE FRONTAL ZONE...WITH
CHANCES FOR THUNDER EXPECTED INTO THE DAY TOMORROW. AFTER THE COLD
FRONT PASSES THROUGH...BETWEEN 12 AND 18Z...A STRONG PULL OF
COLDER NW AIR WILL STREAM IN...QUICKLY DROPPING NEAR SURFACE TEMPS
AND CREATING A STRONG LLVL INVERSION. THIS WILL CREATE A LOSS OF
INSTABILITY AND LIKELY PREVENT ANY FURTHER THUNDERSTORM
DEVELOPMENT...ESPECIALLY AS THE UPPER LEVELS BEGIN TO COOL
THROUGH THE EVENING AS WELL. DROPPED MENTION OF THUNDER AS TEMPS
DROPPED THROUGHOUT THE AFTERNOON...WITH COMPLETE LOSS OF
INSTABILITY BY 21Z. WITH TEMPERATURES FALLING SO QUICKLY...LOW TO
MID 30S CAN BE EXPECTED BY AFTER MIDNIGHT. THIS WILL ALLOW FOR ANY
LINGERING MOISTURE IN THE AREA TO POTENTIALLY CHANGE OVER TO A MIX
OF RAIN AND WET SNOW. THIS IDEA HAS CHANGED LITTLE FROM THE
PREVIOUS FORECAST PACKAGES...AND SHOULD BE MINIMAL ENOUGH TO CAUSE
LITTLE TO NO IMPACTS. GROUND TEMPS WILL STILL BE WARM ENOUGH TO
PREVENT ANY STICKING TO SURFACES THROUGH 12Z FRIDAY.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 252 PM EDT WED MAR 25 2015

AT THE BEGINNING OF THE LONG TERM PERIOD THE EASTERN U.S. TROUGH
WILL BE DEEPENING AND COLD AIR ADVECTION WILL BE UNDERWAY ACROSS THE
FORECAST AREA IN THE WAKE OF A COLD FRONTAL PASSAGE. COLD AIR WILL
CONTINUE TO POUR INTO THE AREA THROUGH SATURDAY MORNING...WITH 85H
TEMPERATURES FALLING TO BETWEEN -10 TO -14 C BY 12Z SATURDAY. LOW
TEMPERATURES SATURDAY MORNING WILL BE DEPENDENT ON SKY COVER. AT
THIS TIME IT APPEARS THERE WILL BE CONSIDERABLE CLOUD COVER
LINGERING FRIDAY NIGHT...BUT LOWS INTO THE MID AND UPPER 20S STILL
LOOK GOOD. ANY LINGERING PRECIPITATION FRIDAY NIGHT WILL BE IN
THE FORM OF FLURRIES OR LIGHT SNOW SHOWERS. SURFACE HIGH PRESSURE
WILL NOSE ITS WAY INTO THE OH VALLEY ON SATURDAY...AND CLEARING
SKIES WILL ALLOW FOR BETTER RADIATIONAL COOLING SATURDAY NIGHT...
ESPECIALLY IN THE EASTERN VALLEYS WHERE DECOUPLING WILL OCCUR.

BY SUNDAY NIGHT A WEAK COLD FRONT WILL BE APPROACHING THE
AREA...BRINGING ANOTHER CHANCE OF RAIN. THERE WILL BE LITTLE IMPACT
ON TEMPERATURES WITH THIS FRONTAL PASSAGE. IN FACT NEXT WEEK WILL
SEE A SIGNIFICANT WARM UP AS THE LONG WAVE TROUGH IN THE EASTERN
U.S. SHIFTS EAST AND THE MEAN FLOW DEAMPLIFIES OVER OUR REGION. A
SOUTHERN STREAM SYSTEM WILL BRING A CHANCE FOR RAIN FOR THE MIDDLE
OF THE WEEK.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 154 AM EDT THU MAR 26 2015

VFR CONDITIONS WILL BE MAINTAINED THROUGH 12Z...WITH JUST SOME CU
AT AROUND 5K FEET AGL FROM TIME TO TIME. CONVECTION WILL THEN
THREATEN FROM THE WEST BETWEEN 12 AND 16Z...WITH
CEILINGS/VISIBILITIES DROPPING DOWN TO MVFR. AS A COLD FRONT
SHIFTS SOUTHEAST ACROSS THE AREA THIS AFTERNOON...WIDESPREAD
PRECIPITATION AND CEILINGS LOWERING TO IFR ARE EXPECTED. LIGHT
WINDS OVERNIGHT WILL PICK UP TOWARDS DAWN AND ESPECIALLY BY MID-
MORNING. SOUTHWEST WINDS OF AROUND 10 KTS...WITH GUSTS RANGING
FROM 15 TO 20 KTS...WILL SHIFT TO THE NORTHWEST AS THE FRONT
PASSES BY TO THE SOUTHEAST.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...GEOGERIAN
SHORT TERM...JMW
LONG TERM...SBH
AVIATION...GEOGERIAN



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.