Flash Flood in Kentucky, August 29 to 30, 2004

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
455 AM MON AUG 30 2004

.DISCUSSION...

07Z SFC ANALYSIS SHOWS THAT THE COLD FRONT HAS ALMOST ENTIRELY
WASHED OUT OVER CENTRAL KENTUCKY. THE REMAINS OF GASTON IS NOW THE
MAIN DRIVING FORCE FOR THE WEATHER OF THE EASTERN THIRD OF THE
NATION. WEAK HIGH PRESSURE...NOW PERCHED OVER MICHIGAN AND ILLINOIS
WITH ITS DRIER AND COOLER AIR...IS POISED TO ENTER THE OHIO VALLEY.
THE HERALDED RAINS OF THE FRONT HAVE TURNED OUT TO BE NO MORE THAN A
FEW SHOWERS DURING LAST EVENING AND OVERNIGHT WHILE FAR EAST
KENTUCKY SAW SOME DECENT RAINFALL AMOUNTS THANKS TO AN ENHANCEMENT
EFFECT FROM GASTON. THE HIGH MOISTURE CONTENT IN THE AIR...WITH
DEWPOINTS IN THE UPPER 60S...AND SOME CLEARING BETWEEN THE FRONT AND
THE CLOUDS FROM GASTON HAVE LED TO ANOTHER NIGHT OF WIDESPREAD LIGHT
FOG WITH PATCHY DENSE FOG LIKELY IN THE VALLEYS EARLY THIS MORNING.

THE MODELS ARE IN DECENT AGREEMENT WITH THE LIGHT FLOW PATTERN ALOFT
FOR THE NEXT WEEK OR SO. GASTON/S RIDE NORTH HAS DELAYED THE
WEAKENING TROUGH OVER THE OHIO VALLEY. AS THE TROPICAL SYSTEM PULLS
OUT TO THE NORTHEAST LATER TONIGHT IT WILL LEAD THE TROUGH NORTHEAST
AS WELL. WITH THE JET STREAM WELL TO THE NORTH THE SFC PATTERN WILL
DOMINATE OUR WEATHER INTO NEXT WEEKEND. TOWARD THE END OF THE WEEK
IT IS LOOKING INCREASINGLY PROBABLE THAT A WEAK RIDGE OVER THE
SOUTHEAST WILL BE PIERCED BY THE NEXT MAJOR TROPICAL SYSTEM...
FRANCES. THE RESULTING COURSE OF THIS HURRICANE COULD HAVE A BIG
EFFECT ON EAST KENTUCKY/S WEATHER BY THE END OF NEXT WEEKEND.

SENSIBLE WEATHER WILL FEATURE SCATTERED SHOWERS AND THUNDERSTORMS
AROUND TODAY AS DRIER AIR ONLY SLOWLY FILTERS INTO THE AREA WHILE
THE FRONT DRIFTS FURTHER EAST. EXPECT A COUPLE OF SHOWERS TO LINGER
INTO THE EVENING OVER THE FAR EAST BEFORE HIGH PRESSURE TAKES OVER.
CLEARING SKIES TONIGHT WITH LOW LEVEL MOISTURE REMAINING WILL BE A
RECIPE FOR ANOTHER FOGGY NIGHT WITH DENSE FOG LIKELY IN THE VALLEYS.
TUESDAY WILL BE A PLEASANT DAY UNDER A MOSTLY SUNNY SKY WITH LESS
HUMIDITY. THE HIGH PRESSURE AREA WILL SLOWLY MODERATE THROUGH THE
WEEK WITH ENOUGH WARMTH AND MOISTURE RETURNING BY THE WEEKEND FOR A
RENEWED  THREAT OF SHOWERS AND THUNDERSTORMS. HALF AN EYE WILL NEED
TO BE KEPT ON FRANCES FOR THE LATTER PART OF THE WEEKEND.

MOS TEMPS CAME IN CLOSE FOR TODAY AND TONIGHT. DID NOT STRAY
FAR...BUT TO GO A COUPLE OF DEGREES WARMER ON HIGHS TODAY THAN THE
MAV. PREFERRED THE COOLER MAV HIGHS FOR TUESDAY...UNDERCUTTING THE
FWC BY A DEGREE OR TWO. DO LIKE THE VALLEY TO RIDGE TEMP SPLIT SHOWN
BY THE FWC FOR TUESDAY NIGHT...REFLECTED THIS IN MY GRIDS. FOR POPS
HAVE BACKED OFF THE LIKELY AND KEPT THINGS FIRMLY IN THE CHANCE
CATEGORY TODAY...CLOSER TO THE NGM POPS RATHER THAN MAV FOR MET.
ALSO DROPPED POPS OFF QUICKER TONIGHT...HOLDING ON TO JUST A SLIGHT
CHANCE IN THE FAR EAST.

AS FOR IFPS/GFE GRIDS...USED MY USUAL PROCEDURE TO POPULATE THE
TEMP/DEW POINT AND WIND GRIDS FROM THE MESOETA THROUGH 60 HOURS. HAD
TO RAISE MAX TEMPS A FEW DEGREES FOR TUESDAY. THE REST OF THE
FORECAST WAS IN GOOD SHAPE WITH A GENERAL LESSENING IN POPS THROUGH
THE NEXT 36 HOURS AS GASTON LITERALLY STEALS OUR THUNDER. HAD TO
REWORK THE SKY AND POP GRIDS IN THE EXTENDED AS ONCE AGAIN IT LOOKS
LIKE THE TEMPORAL EDITOR WAS USED IN ABSOLUTE MODE WIPING OUT ANY
AREAL GRADIENT TO THE GRIDS. THE NET RESULT OF THIS WAS TO MAKE FOR
A DRIER FORECAST AT THE END OF THE WORK WEEK...LEANING TOWARD THE
LATEST GFS RUN.

&&

.PREV DISCUSSION...

345 PM SUN AUG 29 2004

FOR THE PERIOD SUNDAY NIGHT THROUGH WEDNESDAY NIGHT.
USED A BLEND OF THE ETA80 AND GFS80 MODELS...WITH A BIT MORE
INFLUENCE FROM THE GFS MODEL...FOR TIMING AND SPEED OF APPROACHING
COLD FRONT. IT LOOKS AS IF THE PRESENCE OF GASTON WILL CAUSE THE
FRONT TO CONTINUE MOVING VERY SLOWLY EASTWARD.
INITIALLY...CONVECTION WAS SUPPRESSED DUE TO WIDESPREAD HIGH CLOUD
COVER ACROSS CWA. HOWEVER...SEVERAL CLEAR AREAS HAD DEVELOPED ACROSS
EASTERN KY BY 2 PM. SOME SHOWERS AND STORMS ALREADY FIRING ALONG
AND AHEAD OF FRONT SINCE ABOUT NOON IN AREAS OF THINNER CLOUD COVER.
ANTICIPATE THE ADDITIONAL CLEARING WILL ALLOW THE ATMOSPHERE TO
DESTABILIZE AND MORE WIDESPREAD CONVECTIVE ACTIVITY TO BEGIN FORMING
LATE THIS AFTERNOON AND EVENING. MODEL SOUNDINGS AND CROSS SECTIONS
STILL SHOWING ENOUGH INSTABILITY AND VERTICAL MOTION TO SUSTAIN
SHOWER AND STORM ACTIVITY THROUGHOUT THE OVERNIGHT HOURS AS FRONT
MARCHES EASTWARD. FORECAST STILL PRETTY MUCH ON TRACK...ESPECIALLY
IN REGARD TO TEMPERATURES...SO NO BIG CHANGES WERE MADE WITH TEMPS.
LOOKS LIKE FRONT WILL EXIT THE REGION SOMETIME MONDAY...USHERING IN
COOLER...DRIER AIR FOR THE MIDDLE OF THE WORK WEEK. KEPT IN SLIGHT
CHANCE POPS FOR MONDAY NIGHT TO ACCOUNT FOR ANY STRAY SHOWERS THAT
MAY FORM IN NORTHWEST FLOW WEST OF MOUNTAINS IN EASTERN CWA BEHIND
THE FRONT.

FOR THE PERIOD WEDNESDAY NIGHT THROUGH SUNDAY...
THE GFS IS AGAIN FAIRLY CONSISTENT FOR OUR AREA DURING THIS TIME
FRAME...BRINGING SURFACE HIGH PRESSURE FROM THE GREAT LAKES AT
MIDWEEK TO A POSITION OFF THE NEW ENGLAND COAST BY THE WEEKEND.
THE SURFACE HIGH INITIALLY PROVIDES RELATIVELY DRY DEW POINTS
(LIKELY IN THE UPPER 50S/LOWER 60S)...AND THE ATMOSPHERE ALOFT IS
RATHER BENIGN WITH THE WESTERLIES RETREATING FURTHER NORTH.
HENCE...SKIES SHOULD BE MOSTLY CLEAR ON WEDNESDAY AND WEDNESDAY
NIGHT. BY THURSDAY THE FLOW AROUND THE DEPARTING HIGH STARTS TO
CARRY IN GREATER LOW LEVEL MOISTURE FROM THE SOUTHEAST CONUS. UPPER
LEVEL FEATURES WILL BE WEAK...BUT ON FRIDAY AND SATURDAY THE AREA IS
INDICATED TO BE ON THE RIGHT SIDE OF AN ANTICYCLONIC SUBTROPICAL
UPPER JET. WITH THE AFOREMENTIONED SCENARIO...HAVE OPTED TO INCLUDE
A MENTION OF PRECIP FROM THURSDAY THROUGH THE REST OF THE
FORECAST...WITH THE GREATEST POPS (40%) ON THU AND FRI. HAVE GONE
CLOSE TO MOS TEMPS WHICH ARE NEAR CLIMO. ACTUAL TEMPS WILL LIKELY
END UP QUITE DEPENDENT ON AMOUNT OF CLOUDS/PRECIP LATE IN THE WEEK.

&&

1209 PM EDT SUN AUG 29 2004

JUST UPDATED THE FORECAST FOR PRECIPITATION ON DAYS 5 THROUGH 7.
HAVE INCLUDED POPS THROUGHOUT THIS TIME FRAME. NEW GUIDANCE CAME IN
LAST NIGHT LOOKING MORE SUPPORTIVE OF PRECIP. A HUMID AIR MASS
RETURNS ON THE BACK SIDE OF THE DEPARTING SURFACE HIGH LATE IN THE
WEEK...AND THE RIGHT SIDE OF A WEAK ANTICYCLONIC UPPER SUBTROPICAL
JET MAY ALSO PROVIDE SOME LIFT.

555 AM EDT SUN AUG 29 2004

08Z SFC ANALYSIS SHOWS A BROAD AREA OF LOW PRESSURE ORIENTED
SOUTHWEST TO NORTHEAST THROUGH THE OHIO VALLEY. THE EFFECTS OF
STRONG TROPICAL STORM GASTON ARE ALSO SEEN WITH GUSTY WINDS IN THE
OBS ALONG THE COAST OF SOUTH CAROLINA. ON SATELLITE...THE COLD CLOUD
TOPS OF THE TROPICAL SYSTEM SHOW UP QUITE WELL WITH A MASS OF WARMER
CLOUDS THROUGH THE OHIO VALLEY. THE CLOUDS ASSOCIATED WITH THE
EARLIER THUNDERSTORMS ARE WARMING AS THEY DRIFT NORTHEAST THROUGH
WEST VIRGINIA. ON RADAR...THE EARLIER STORMS HAVE RAINED THEMSELVES
OUT...BUT NOT BEFORE LEAVING A RADAR ESTIMATED THREE TO FOUR INCHES
OF RAIN OVER CENTRAL PIKE COUNTY. TEMPERATURES THROUGH THE AREA ARE
HANDCUFFED TO THEIR DEWPOINTS...NOT FAR FROM 70 DEGREES. AGAIN THERE
IS WIDESPREAD LIGHT FOG AROUND WITH SOME DENSE FOG LIKELY IN THE
DEEPER VALLEYS.

THE MODELS ARE HAVING TROUBLES AGREEING ON THE SPECIFICS INVOLVED
WITH THE BROAD TROUGH THAT SWEEPS THROUGH THE OHIO VALLEY BY THE
START OF THE NEW WORK WEEK. THE GFS HAS THE FASTEST SOLUTION TAKING
THE TROUGH AXIS THROUGH EAST KENTUCKY MONDAY AFTERNOON IN RESPONSE
TO THE MAIN LEAD SHORTWAVE PASSING. DURING THIS SAME TIME THE ETA
KEEPS THE TROUGH FLAT THROUGH THE OHIO VALLEY WAITING FOR THE SECOND
WAVE TO DIVE IN FROM THE NORTHERN PLAINS BY TUESDAY MORNING. THE GFS
PICKS UP ON THIS FEATURE BY MIDDAY TUESDAY...REENFORCING THE TROUGH
AND DEEPENING IT OVER THE OHIO VALLEY. WILL FOLLOW A COMPROMISE
BETWEEN THESE TWO SCENARIOS FOR THE GRIDS. LIGHT FLOW FOLLOWS FOR
MID WEEK WITH GENERAL RIDGING OVER THE SOUTHEAST AND WEAK TROUGHING
APPROACHING FROM THE WEST. THE TROPICS WILL THROW A COUPLE OF FLIES
INTO THE OINTMENT DURING THE NEXT SEVEN DAYS OR SO. GASTON IS LIKELY
RESPONSIBLE FOR THE TROUGH SLOWING A BIT IN THE NEAR TERM AND
FRANCES LOOKS TO BECOME A BIGGER CONCERN AFTER NEXT WEEKEND.

SENSIBLE WEATHER WILL FEATURE A LAST WARM AND HUMID DAY AS THE BROAD
SFC FRONT PRESSES INTO KENTUCKY. FOR LATER TODAY SLOW MOVING
THUNDERSTORMS ARE A GOOD BET. PLENTY OF MOISTURE WILL BE IN PLACE...
ALONG WITH SOME UPPER LEVEL ENERGY AND DIVERGENCE ALOFT FROM A JET
STREAK THAT PUTS EAST KENTUCKY IN ITS RIGHT ENTRANCE REGION.
ACCORDINGLY...WILL FORECAST TEMPERATURES A CATEGORY OR TWO BELOW
YESTERDAY/S HIGHS. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO LINGER
TONIGHT AS THE FRONT STALLS OVERHEAD. THIS FRONT WILL CONTINUE TO BE
A NUISANCE ON MONDAY...ESPECIALLY EAST OF JACKSON WITH RENEWED
THUNDERSTORMS POSSIBLE DURING THE PEAK HEATING OF THE DAY.
FINALLY...MONDAY NIGHT SHOULD SEE DRIER AIR WORK DEEP ENOUGH INTO
KENTUCKY TO END THE THREAT OF SHOWERS. THE HIGH PRESSURE AREA
ACCOMPANYING THIS DRIER AIR WILL NOT BE THAT STRONG...THOUGH...AND
WILL ALLOW A RETURN OF SCATTERED DIURNALLY DRIVEN CONVECTION FROM
MIDWEEK ON AS ITS ONCE COOL AIR MODERATES AND HUMIDITY RETURNS.

MAV AND MET MOS TEMPS WERE JUST A TAD TOO COOL TODAY BUT LOOKED
BETTER THAN YESTERDAY WITH CLOUDS AND SHOWERS DEVELOPING TO HELP
KEEP TEMPS DOWN. THE NUMBERS LOOK GOOD TONIGHT AND AGAIN FOR MONDAY
...DID NOT STRAY FAR. FOR POPS GENERALLY WENT WITH THE HIGHER MET
NUMBERS THROUGH THE SHORT TERM FORECAST.

AS FOR IFPS/GFE GRIDS...USED MY USUAL PROCEDURE TO POPULATE THE
TEMP/DEW POINT AND WIND GRIDS FROM THE MESOETA THROUGH 60 HOURS.
WHILE THESE CAME IN FAIRLY CLOSE TO WHAT I WANTED...STILL HAD TO
TWEAK MAX TEMPS A BIT HIGHER TODAY...ALSO FINE TUNED THE CCF POINTS.
THE REST OF THE FORECAST WAS IN GOOD SHAPE WITH JUST A SLOWER TREND
NEEDED FOR THE FRONT ON MONDAY. REWORKED THE SKY AND POP GRIDS IN
THE EXTENDED AS IT LOOKS LIKE THE TEMPORAL EDITOR WAS USED IN
ABSOLUTE MODE WIPING OUT ANY AREAL GRADIENT TO THE GRIDS.

&&

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

&&

RICHEY/HAL

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSON KY
410 PM EDT SUN AUG 29 2004

KYZ044-050>052-058>060-068-069-079-080-083>088-104-106>120-302005-
BATH KY-BELL KY-BREATHITT KY-CLAY KY-ELLIOTT KY-ESTILL KY-FLEMING KY-
FLOYD KY-HARLAN KY-JACKSON KY-JOHNSON KY-KNOTT KY-KNOX KY-LAUREL KY-
LEE KY-LESLIE KY-LETCHER KY-MAGOFFIN KY-MARTIN KY-MCCREARY KY-
MENIFEE KY-MONTGOMERY KY-MORGAN KY-OWSLEY KY-PERRY KY-PIKE KY-
POWELL KY-PULASKI KY-ROCKCASTLE KY-ROWAN KY-WAYNE KY-WHITLEY KY-
WOLFE KY-
410 PM EDT SUN AUG 29 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN KENTUCKY.

.DAY ONE...TODAY AND TONIGHT.

THUNDERSTORMS WITH LOCALLY HEAVY RAIN WILL BE POSSIBLE TONIGHT.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.

THERE WILL BE A CHANCE OF THUNDERSTORMS ON MONDAY AND AGAIN FOR
THURSDAY THROUGH SATURDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED.

RICHEY