Heat in Kentucky, August 9, 2010

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
1003 AM EDT MON AUG 9 2010

.SHORT TERM.../THE REST OF TODAY/...UPDATED

MOISTURE IS ON THE INCREASE WITH 70 DEGREE DEWPOINTS OBSERVED WEST
OF I-75. SATELLITE IMAGERY SHOWS SOME ACCAS DOWN THERE AS WELL AND
WITH PWATS JUMPING BACK UP TO OVER 1.5 INCHES ON A LAPS SOUNDING
OVER MONTICELLO... SUSPECT WE MAY GET A SHOWER OR TWO ALONG THE
TENNESSEE BORDER THIS AFTERNOON. HRRR DOES INDEED INDICATE SOME
CONVECTION OVER OUR SOUTHWEST COUNTIES SO WILL ADD A 20 POP
SOUTHWEST OF A LINE FROM SOMERSET TO MIDDLESBORO. DO NOT PLAN TO
MENTION THUNDER THOUGH AS STOUT MID LEVEL CAP THIS AFTERNOON SHOULD
LIMIT UPDRAFT GROWTH.

OTHERWISE... CLOUD COVER WAS NUDGED UPWARDS SOME ESPECIALLY OVER THE
CUMBERLAND VALLEY BUT ALSO OVER THE REST OF THE AREA TO ADDRESS THE
WIDESPREAD BUT THIN CIRRUS. KNOCKED A DEGREE OFF EXPECTED HIGHS OVER
OUR SOUTHWEST COUNTIES DUE TO THE INCREASED SKY COVER BUT CIRRUS
OVER THE REST OF THE AREA SHOULD NOT SIGNIFICANTLY AFFECT TEMPS AND
CONTINUE TO EXPECT HIGHS AROUND 90 FOR MOST LOCATIONS.

THE PREVIOUS SHORT TERM FORECAST DISCUSSION FOLLOWS...

/TODAY THROUGH TUESDAY NIGHT/

THE MODELS CONTINUE TO BE IN QUITE GOOD AGREEMENT ALOFT THROUGH THE
SHORT TERM PORTION OF THE FORECAST. STRONG RIDGING BUILDS INTO THE
TENNESSEE AND SOUTHERN OHIO VALLEYS PROTECTING OUR REGION FROM A
STORM TRACK THAT WILL HOLD OFF TO WEST AND NORTH UNTIL LATER IN THE
WEEK. AS SUCH...HAVE FOLLOWED WEATHER SPECIFICS MOST CLOSELY FROM THE
NAM12 AND ALSO LEANED ON A HEAVY DOSE OF PERSISTENCE.

SENSIBLE WEATHER WILL FEATURE AREAS OF VALLEY FOG...LOCALLY DENSE...
DISSIPATING BY MID MORNING AND ANOTHER PARTLY TO MOSTLY SUNNY AND
VERY WARM DAY COMMENCING. DO EXPECT AN INCREASE IN DEWPOINTS TODAY...
BUT NOT ENOUGH TO KICK THE HEAT INDEX UP TOWARD ADVISORY CRITERIA.
A BETTER CHANCE OF THAT WILL BE TOMORROW AS THE DEWPOINTS RISE MORE
SUBSTANTIALLY AND LIKEWISE...ACTUAL TEMPERATURES PEAK SEVERAL DEGREES
HIGHER. BARRING ANY INFLUENCE FROM THICK DEBRIS CLOUDS INBOUND FROM
MCS ACTIVITY TO THE NORTHWEST...EXPECT HEAT ADVISORY CRITERIA TO BE
REACHED OVER A SIGNIFICANT PORTION OF THE CWA FOR TUESDAY. WILL HOLD
OFF ON ANY HEADLINES AT THIS TIME...THOUGH...ALLOWING LATTER SHIFTS
TO REFINE THE SPECIFICS. WILL CONTINUE TO HIGHLIGHT THE RETURNING
HEAT IN THE WEATHER STORY AND HWO. ASIDE FROM THE HEAT...HAVE
FOLLOWED A MODIFIED PERSISTENCE FOR FOG FORMATION EACH NIGHT AND
WARMED THE OBSERVED LOW TEMPERATURES A FEW DEGREES EACH NIGHT. DID
MODERATE THE EXTREMES OF THE STANDARD RIDGE TO VALLEY TEMPERATURE
SPLIT ON TUESDAY NIGHT DUE TO AN ANTICIPATED INCREASE IN HIGH CLOUDS
WITH TIME.

AS FOR TEMPERATURES HAVE NUDGED UP A BLEND OF PERSISTENCE...INHERITED
GRIDS...AND MET NUMBERS AS THE OBS CAME IN A TAD HIGHER THAN FORECAST
FOR MAXES YESTERDAY. EVEN SO...THESE ARE STILL WELL BELOW THE
SCORCHING MAV NUMBERS. FOR TUESDAY ESSENTIAL BLENDED THE MET WITH
THE MAV TO ACHIEVE REASONABLE VALUES GIVEN THE FORECAST 850 TEMPS AND
SIMILAR RESULTS LAST TIME...ALONG WITH THE MITIGATING POTENTIAL FOR
A DECENT INCREASE IN AFTERNOON CLOUD COVER. KEPT POPS THROUGH THE
PERIOD MAINLY IN THE SINGLE DIGITS...PEAKING IN THE NORTH DURING THE
LATE AFTERNOON EACH DAY...MOST SIMILAR TO THE MET GUIDANCE.

.LONG TERM.../WEDNESDAY THROUGH SUNDAY/

ONLY MADE MINOR TWEAKS TO THE EXTENDED PORTION OF THE FORECAST...
MAINLY TO NUDGE UP SKY COVER. DID ALSO LIFT POPS A FEW PERCENTAGES PER
THE LATEST CONSENSUS MODEL AND MOS GUIDANCE FOR A BRIEF PERIOD OF
TIME ON WEDNESDAY NIGHT AND INTO THURSDAY.

THE AFTERNOON EXTENDED FORECAST DISCUSSION FOLLOWS...

SURFACE HIGH PRESSURE WILL BE SITUATED TO OUR SE TO START THE
PERIOD...WITH A WEAK STALLED FRONTAL BOUNDARY JUST TO OUR NORTH. AN
UPPER LEVEL WAVE WILL BE HEADING ESE OVER THE GREAT LAKES ON
WEDNESDAY. WIND FLOW BETWEEN THE SURFACE HIGH AND THE FRONT WILL
BRING INCREASING MOISTURE. MEANWHILE...THE UPPER LEVEL WAVE WILL
WORK TO WEAKEN/FLATTEN AN UPPER RIDGE OVER THE SE CONUS. WITH THIS
HAPPENING...DEEP CONVECTION WILL AGAIN BECOME A POSSIBILITY...FIRST
AT AREAS FURTHEST REMOVED FROM THE UPPER RIDGE CENTER AND CLOSEST TO
THE SURFACE BOUNDARY. HAVE USED 20 PERCENT POP IN OUR NORTHERN
COUNTIES ON WEDNESDAY AFTERNOON. BEING AT THE EDGE OF THE UPPER
RIDGE WITH WNW FLOW ALOFT...NOCTURNAL MCS TYPE ACTIVITY WILL ALSO BE
A CONCERN...AND HAVE USED A 20-30 PERCENT POP WEDNESDAY NIGHT WITH
THE HIGHEST POPS IN THE NORTH.

THE SURFACE BOUNDARY WILL HAVE TROUBLE MAKING IT FURTHER SOUTH...AT
LEAST IN TERMS OF ANY MEANINGFUL CHANGE IN AIR MASS...AND THE UPPER
LEVEL PATTERN WITH WNW FLOW ALOFT IS ALSO EXPECTED TO LINGER. THIS
WILL LEAVE US WITH THE SAME GENERAL SCENARIO AT LEAST UNTIL LATE IN
THE FORECAST PERIOD.

THERE IS DISCREPANCY BETWEEN THE GFS AND ECMWF NEXT WEEKEND. THE GFS
FAVORS AT LEAST MAINTAINING OR EVEN DEEPENING AN UPPER TROUGH OVER
SE CANADA AND THE GREAT LAKES...WHILE THE ECMWF IS TENDING TO HOLD
THE UPPER LOW RESPONSIBLE FOR THIS FURTHER TO THE NORTH AND ALLOWS
THE SE CONUS UPPER RIDGE TO BUILD NORTH TOWARD US AGAIN. BECAUSE OF
THIS...THE GFS BRINGS A COLD FRONT INTO THE REGION ON SUNDAY WHILE
THE ECMWF DOES NOT. DO NOT HAVE MUCH CONFIDENCE IN THE OUTCOME...AND
HAVE USED JUST A MODEST INCREASE IN POPS FOR SUNDAY...GOING WITH 30
PERCENT VERSUS 20 PERCENT ON FRIDAY NIGHT AND SATURDAY.

IN TERMS OF TEMPS...AT THE START OF THE FORECAST PERIOD THE 00Z AND
06Z GFS 850 MB TEMPS WERE WARMER THAN THE 00Z GFS ENSEMBLE OR ECMWF.
THE 12Z GFS CAME IN A BIT COOLER THAN THE PREVIOUS COUPLE OF RUNS.
HAVE UNDERCUT THE OPERATIONAL RUNS OF THE GFS AND THE GFS MOS BY
SEVERAL DEGREES FOR HIGH TEMPS ON WED AND THU...HAVING MORE
CONFIDENCE IN THE ENSEMBLE AND ITS SUPPORT FROM THE ECMWF. NEXT
WEEKEND...HAVE USED LITTLE CHANGE IN TEMPS...BUT REALISTICALLY IT
COULD BE WARMER OR COOLER BASED ON THE RANGE OF MODEL SOLUTIONS
DESCRIBED IN THE LAST PARAGRAPH.

&&

.AVIATION.../12Z TO 12Z/

A BUILDING UPPER LEVEL RIDGE OF HIGH PRESSURE WILL KEEP VFR
CONDITIONS IN PLACE ACROSS THE AREA THROUGH THE MAJORITY OF THE TIME.
MVFR/IFR FOG WILL CONTINUE TO PERSIST IN THE VALLEYS BETWEEN 05 AND
13Z. PASSING HIGH CLOUDS AS WELL AS SOME MAINLY DIURNALLY DRIVEN CU
WILL ALSO BE SEEN. WINDS WILL ALSO REMAIN LIGHT THROUGH THE PERIOD.

&&

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

&&

SHORT TERM...GREIF/ABE
LONG TERM....HAL/GREIF
AVIATION...GEOGERIAN

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE JACKSON KY
1008 AM EDT MON AUG 9 2010

KYZ044-050>052-058>060-068-069-079-080-083>088-104-106>120-101700-
FLEMING-MONTGOMERY-BATH-ROWAN-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-
1008 AM EDT MON AUG 9 2010

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EASTERN KENTUCKY.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

HAZARDOUS WEATHER IS NOT EXPECTED AT THIS TIME.

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

TEMPERATURES IN MOST LOCATIONS WILL WARM INTO THE 90S EACH DAY THIS
WEEK...ALONG WITH INCREASING HUMIDITY LEVELS. THE HEAT INDEX WILL
PEAK AROUND 100 DEGREES EACH AFTERNOON FROM TUESDAY THROUGH THURSDAY.

THUNDERSTORMS WILL BE POSSIBLE FROM WEDNESDAY THROUGH SUNDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED.

GREIF/ABE