Flash Flood and Flood in Kentucky, September 17 to 18, 2012

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON KY
410 AM EDT MON SEP 17 2012

.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 345 AM EDT MON SEP 17 2012

...HEAVY RAIN EVENT EXPECTED TONIGHT...

07Z SFC ANALYSIS SHOWS A DEVELOPING AREA OF LOW PRESSURE OVER THE
LOWER MISSISSIPPI VALLEY AND A SHARP COLD FRONT TO THE NORTHWEST.
THESE TWO FEATURES WILL COMBINE OVER EAST KENTUCKY LATER TODAY AND
TONIGHT TO RESULT IN AN EXTENDED PERIOD OF MODERATE TO EXCESSIVE
RAINFALL. ALREADY THE WARM FRONT AHEAD OF THE SOUTHERN LOW HAS
STARTED TO KICK OFF CELLS OF CONVECTION ALONG THE TENNESSEE BORDER
WITH POCKETS OF SPRINKLES NOTED FURTHER NORTH THROUGH EAST KENTUCKY.
MID AND HIGH LEVEL CLOUDS COVER THE CWA AND THAT HAS EFFECTIVELY SHUT
OFF THE NOCTURNAL RADIATION MAKING FOR FAIRLY UNIFORM TEMPERATURES AT
THIS HOUR EXHIBITING ONLY A SMALL RIDGE TO VALLEY DIFFERENCE. A LARGER
STRIATION EXIST FROM NORTH TO SOUTH PRIMARILY BASED ON THE HIGHER
DEWPOINTS IN THE SOUTH AT THE LEADING EDGE OF THE NORTHWARD MOISTURE
SURGE EARLY THIS MORNING.

THE MODELS REMAIN IN NEAR LOCK STEP AGREEMENT WITH HOW THE PATTERN
ALOFT WILL EVOLVE OVER THE SHORT TERM. AN EASTWARD DRIFTING SOUTHERN
LOW WILL BECOME ABSORBED BY A...MORE SOUTH THAN EAST MOVING...
DESCENDING TROUGH OF AN TYPICALLY AUTUMN MAGNITUDE. AS IT DOES...SO
THE UPPER DYNAMICS BETWEEN THESE TWO FEATURES WILL BE ENHANCED WITH
STRONG LIFT AND UPPER DIVERGENCE PASSING THROUGH EAST KENTUCKY
STARTING LATER TODAY AND LASTING INTO TUESDAY MORNING. HIGH PW AIR
AND A DEVELOPING LOW LEVEL JET WILL ALSO CONTRIBUTE TO THIS SITUATION
AND THE LIKELIHOOD OF EFFICIENT PCPN UNTIL THE TROUGH WHIPS THROUGH
HERE LATER TUESDAY. WITH THE GOOD MODEL AGREEMENT HAVE LEANED MOST
HEAVILY ON THE NAM12 DEPICTION GIVEN IT HIGHER RESOLUTION AND BETTER
MODELING OF THE LOW LEVEL PARAMETERS KEY TO THE ANTICIPATED HEAVY
RAIN DEVELOPMENT.

SENSIBLE WEATHER WILL FEATURE A SLOW BUILD TO THIS LIKELY EXCESSIVE
RAIN EVENT WITH SHOWERS AND EVENTUALLY THUNDERSTORMS CREEPING NORTH
INCREASING THEIR COVERAGE WITH TIME. EXPECT THE MAIN OVERRUNNING RAIN
SHIELD TO LIFT OVER THE BULK OF THE CWA DURING THE AFTERNOON WITH
SHOWERS AND EMBEDDED THUNDERSTORMS. THE HEAVY RAIN WILL BE A BIGGER
THREAT LATER THIS EVENING AND TONIGHT WHEN THE PHASING OF THE UPPER
LEVEL FEATURES TAKES PLACE AND SOME COUPLING TO THE JET STREAKS
INVOLVED WILL MAXIMIZE THE LIFT OVER THE AREA. ACCORDINGLY...HAVE
ADDED HEAVY RAIN INTO THE GRIDS AND BEEFED UP THE QPF TONIGHT.
DESPITE THE HIGH FFG VALUES THROUGH THE AREA ATTM...THANKS TO A
RELATIVELY DRY WEEK OR SO...WILL ISSUE A FLOOD WATCH FROM NOON TODAY
THROUGH NOON TUESDAY AS THE DURATION AND EXTENSIVE AREA OF LIKELY
THREE PLUS INCH RAINS COULD LEAD TO CERTAINLY SOME URBAN AND SMALL
STREAM FLOOD ISSUES WITH FLASH FLOODING A POTENTIAL SHOULD TRAINING
OR A CONFLUENCE OF THE HEAVIER RAIN BANDS TARGET A PARTICULAR AREA.
THE HEAVIER SHOWERS AND SCATTERED THUNDERSTORMS WILL COME TO AN END
FROM WEST TO EAST DURING THE DAY TUESDAY AS A DISTINCT COLD FRONT
PUSHES THROUGH THE STATE AND USHERS IN COOLER AND DRIER AIR.

FOR TEMPERATURES...FOLLOWED A BLEND OF THE INHERITED GRIDS AND THE
RAW MODEL DATA GIVEN THE HIGH POPS FORECAST THROUGH TUESDAY MORNING
AND CAA STARTING LATER THAT AFTERNOON. DID ALSO GO WITH A MODEL
DERIVED DIURNAL CURVE FOR HOURLY TEMPS. AS FOR POPS...HAVE BASICALLY
MAXED THEM OUT THOUGH THE PERIOD...IN LINE WITH THE MOS GUIDANCE.

A FLOOD WATCH IS FORTHCOMING TO ADDRESS THE EXCESSIVE RAIN THREAT...
PRIMARILY FOR TONIGHT.

.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 410 AM EDT MON SEP 17 2012

THE MODELS ARE IN GOOD AGREEMENT WITH MAINTAINING AN AMPLIFIED
PATTERN ACROSS THE CONUS...WITH EXTENSIVE TROUGHING DOMINATING THE
EAST...WHILE RIDGING STAYS IN PLACE ACROSS THE WEST. THIS ALLOW FOR
ANOTHER BOUT OF UNSETTLED WEATHER LATE IN THE WEEK AND INTO THE
WEAKEN AS WELL AS BOLSTERING THE BELOW NORMAL TEMPERATURES ACROSS
THE OHIO VALLEY.

FOR EASTERN KENTUCKY...SCATTERED SHOWERS WILL ENDING BE IN THE FAR
EAST...WITH MUCH COOLER AIR BEING DRAWN IN BEHIND THE EXITING SHARP
COLD FRONT TUESDAY NIGHT. SURFACE HIGH PRESSURE WILL BUILD IN AND
CONTROL THROUGH THURSDAY NIGHT...PROVIDING DRY WEATHER AND COOL
TEMPERATURES FOR THE COMMONWEALTH. WEDNESDAY NIGHT STILL LOOKS TO BE
THE COOLEST NIGHT...WITH LOWER 40S COMMONPLACE IN THE SHELTERED
VALLEYS. HIGHS ON WEDNESDAY WILL BE IN THE 60S...WITH READINGS ON
THURSDAY MODIFYING TO THE LOWER 70S AS RETURN SOUTHERLY FLOW
ENGAGES.

BY FRIDAY...ANOTHER STOUT SHORT WAVE TROUGH WILL BE DROPPING DOWN OUT
OF SOUTH CENTRAL CANADA...REINFORCING THE MAIN TROUGH ACROSS THE
EASTERN CONUS. THIS WILL BRING ANOTHER COLD FRONT TO THE AREA FROM
LATE FRIDAY THROUGH SATURDAY. MOISTURE WILL BE LIMITED WITH
THIS...SO HAVE MAINTAINED THE GIVEN CHANCE POPS...PEAKING DURING THE
DAY ON SATURDAY.

FOR SUNDAY...UPSLOPE FLOW WILL BE LINGERING IN THE WAKE OF THE
DEPARTED COLD FRONT...WITH PERHAPS ENOUGH MOISTURE TO ALLOW FOR A
FEW LINGERING SHOWERS BEFORE HIGH PRESSURE BUILDS IN ONCE AGAIN.

HIGH TEMPERATURES ON FRIDAY WILL BE CLOSE TO NORMAL...BEFORE TAKING
ANOTHER 5 TO 10 DEGREE HIT FOR THE WEEKEND.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 220 AM EDT MON SEP 17 2012

THOUGH VFR CONDITIONS WILL CONTINUE THROUGH THE FIRST 6 TO 12 HOURS
OF THE TAF PERIOD....THEY WILL LIKELY GO DOWNHILL QUICKLY BY MID
AFTERNOON...TODAY...AS OVERRUNNING SHOWERS AND EMBEDDED THUNDERSTORMS
SET UP OVER OUR AREA. DO EXPECT CIGS AND VIS TO FALL TO MVFR OR LOWER
TOWARD SUNSET AND INTO THE OVERNIGHT HOURS...TONIGHT AS THE CORE OF A
DEVELOPING LOW PRESSURE AREA CROSSES THE REGION. DO NOT ANTICIPATE
ANY FOG OR LOW STRATUS ISSUES FOR THE REMAINDER OF THIS NIGHT WHILE
LATER MONDAY NIGHT SOME MAY BE POSSIBLE DURING THE HEAVIER RAINS.
WINDS THROUGH THE BULK OF PERIOD WILL BE GENERALLY LIGHT AND FROM THE
SOUTH...BUT AFTER 00Z WE COULD SEE THEM PICK UP FROM THE SOUTH AT
NEAR 10 KTS WITH GUSTS AT 15 TO 20 KTS.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH FROM NOON EDT TODAY THROUGH TUESDAY MORNING FOR
KYZ058>060-068-069-079-080-083>088-104-106>120.

&&

SHORT TERM...GREIF
LONG TERM....GEOGERIAN
AVIATION...GREIF

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSON KY
420 AM EDT MON SEP 17 2012

KYZ044-050>052-181130-
FLEMING-MONTGOMERY-BATH-ROWAN-
INCLUDING THE CITIES OF...FLEMINGSBURG...MOUNT STERLING...
OWINGSVILLE...MOREHEAD
420 AM EDT MON SEP 17 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EASTERN KENTUCKY.

.DAY ONE...TODAY AND TONIGHT.

SOAKING RAINS OF ONE TO TWO INCHES IS EXPECTED ACROSS THE BLUEGRASS
AREA OF EAST KENTUCKY FROM THIS AFTERNOON THROUGH TONIGHT FROM AN
EXPECTED PERIOD OF SHOWERS AND THUNDERSTORMS. THE RAINFALL WILL
LIKELY LEAD TO RISES ON AREA CREEKS AND STREAMS AND POSSIBLE MINOR...
NUISANCE FLOODING.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

THUNDERSTORMS WILL BE POSSIBLE TUESDAY MORNING.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE ENCOURAGED TO CALL IN ANY REPORTS OF EXCESSIVE RAINS OR
FLOODING TODAY AND TONIGHT.

KYZ058>060-068-069-079-080-083>088-104-106>120-181130-
ESTILL-POWELL-MENIFEE-ROCKCASTLE-JACKSON-PULASKI-LAUREL-WAYNE-
MCCREARY-WHITLEY-KNOX-BELL-HARLAN-ELLIOTT-MORGAN-JOHNSON-WOLFE-
MAGOFFIN-FLOYD-LEE-BREATHITT-KNOTT-OWSLEY-PERRY-CLAY-LESLIE-LETCHER-
MARTIN-PIKE-
INCLUDING THE CITIES OF...IRVINE...STANTON...FRENCHBURG...
MOUNT VERNON...MCKEE...SOMERSET...LONDON...MONTICELLO...
WHITLEY CITY...CORBIN...WILLIAMSBURG...BARBOURVILLE...MIDDLESBORO...
PINEVILLE...HARLAN...SANDY HOOK...WEST LIBERTY...PAINTSVILLE...
CAMPTON...SALYERSVILLE...PRESTONSBURG...BEATTYVILLE...JACKSON...
HINDMAN...BOONEVILLE...HAZARD...MANCHESTER...HYDEN...WHITESBURG...
INEZ...PIKEVILLE
420 AM EDT MON SEP 17 2012

...FLOOD WATCH IN EFFECT FROM NOON EDT TODAY THROUGH TUESDAY
MORNING...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EASTERN KENTUCKY.

.DAY ONE...TODAY AND TONIGHT.

SHOWERS AND THUNDERSTORMS WILL BRING A LARGE AREA OF TWO TO THREE
INCHES OF RAIN TO A GOOD PORTION OF EAST KENTUCKY FROM TODAY THROUGH
TUESDAY AFTERNOON. THIS RAINFALL WILL LIKELY LEAD TO SIGNIFICANT RISES
ON AREA CREEKS AND STREAMS AS WELL AS THE POTENTIAL FOR FLOODING.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

THUNDERSTORMS WILL BE POSSIBLE TUESDAY. HEAVY RAINS WILL BE A THREAT
THROUGH TUESDAY MORNING.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE ENCOURAGED TO CALL IN ANY REPORTS OF EXCESSIVE RAINS OR
FLOODING TODAY THROUGH TUESDAY.

GREIF