Damaging Wind in Kentucky, July 23, 2002

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
237 PM EDT TUE JUL 23 2002

...FORECAST ISSUES...
FORECAST CHALLENGES REVOLVE AROUND POP CHANCES IN THE SHORT TERM
ALONG WITH HI TEMPS OVER THE NEXT FEW DAYS.  RAIN CHANCES IN THE
EXTENDED ARE A LITTLE CHALLENGING AS WELL.

...MODELS/ZFP...
H5 SYNOPTIC CHART THIS MORNING SHOW A LARGE TROF FROM CENTRAL CANADA
DOWN THROUGH THE NORTHERN OHIO VALLEY WITH A SECONDARY WAVE OVER THE
SOUTHEAST US...LARGE RIDGE OVER THE CENTRAL US WAS SEEN AS WELL.

FORECAST MODELS IN GENERAL AGREEMENT PUSHING WEAK FRONTAL BOUNDARY
THROUGH THE REGION OR JUST PLAIN OUT DISSOLVING IT WITHIN THE NEXT
24 HOURS.  CURRENT RADAR PICS SHOWING AN AREA OF STRATIFORM RAIN
OVER IN THE SDF-FFT-LEX AREA.  OUT AHEAD OF THIS AREA OF LIGHT TO
MODERATE RAIN...A FEW THUNDERSTORMS ARE STARTING TO POP UP WITH THE
HEATING OF THE AFTERNOON.  OVERALL...HIGH CLOUDS HAVE LIMITED THE
STRONG SURFACE HEATING ORIGINALLY FORECAST.  HOWEVER...CURRENT
THINKING IS THAT MORE STORMS WILL FIRE UP LATER THIS AFTERNOON AS WE
APPROACH MAXIMUM HEATING.

FOR TONIGHT AND WEDNESDAY...WILL CONTINUE TO CARRY CHANCE POPS
ACROSS THE AREA. FWC/MAV/MET NUMBERS IN GOOD AGREEMENT TONIGHT WITH
LOWS IN THE UPPER 60S ACROSS MUCH OF THE AREA...BUT NEAR 70 ACROSS
THE FAR SOUTH.  ON WEDNESDAY...WILL BEGIN ENDING PRECIP FROM NORTH
TO SOUTH.  EXPECT A LOT OF CLOUDS AROUND TOMORROW WHICH SHOULD KEEP
TEMPS DOWN SLIGHTLY COMPARED TO PREVIOUS DAY.  LOOKING FOR HIGHS OF
83 TO 88 ACROSS THE AREA.  PLAN ON MENTIONING SOME FOG FOR WED
NIGHT...AS SKIES CLEAR A LITTLE MORE BUT LOW-LEVEL MOISTURE REMAINS
HIGH.

FOR THURSDAY AND FRIDAY...A COUPLE OF H5 WAVES ARE FORECAST TO SCOOT
JUST TO THE NORTH OF THE AREA ON FRIDAY.  WITH SOME UPPER LEVEL
SUPPORT...PLAN ON KEEPING CHANCE POPS IN FOR THU/FRI...MAINLY FOR
AFTERNOON AND EVENING ACTIVITY.  FWC/MAV/MET NUMBERS LOOK GOOD AND
PLAN ON USING A BLEND.

...EXTENDED...
UPPER LEVEL PATTERN FAIRLY AMPLIFIED IN THE BEGINNING OF THE
EXTENDED BUT UPPER LEVEL RIDGING TAKES OVER BY THE END OF THE
WEEKEND.  SEVERAL H5 WAVE ARE FORECAST TO PASS THROUGH THROUGH THE
REGION DURING THE FIRST PART OF THE EXTENDED.  THE FIRST OF THESE
WAVES PASSES THROUGH LATE FRI AND EARLY SATURDAY...WITH THE SECOND
ONE PASSING BY SAT NITE AND THEN THE FINAL ONE PASSING BY SUNDAY
NIGHT.  WITH THE WAVES PASSING BY AND GOOD SOUTHWESTERLY FLOW AT THE
SURFACE EXPECT CONVECTION TO POP UP DURING THE AFTERNOONS...MAINLY
SATURDAY THROUGH MONDAY.  AS UPPER LEVEL RIDGE AXIS MOVES OVER THE
AREA ON TUESDAY...CONVECTION SHOULD BE HELD TO A MINIMUM.
THUS...PLAN ON KEEPING TUESDAY DRY AT THIS POINT.  NOT MUCH CHANGE
IN TEMPERATURES FOR THIS PACKAGE.  LOOKING AT LOWS AROUND 70 AND
HIGHS IN THE UPPER 80S TO NEAR 90...WHICH IS SLIGHTLY ABOVE NORMAL
FOR THIS TIME OF THE YEAR.

...GRIDS...
FORECAST DATABASE IS GOOD SHAPE.  DID THE USUAL RE-LOAD OF 1HR T/TD
AND WINDS FROM THE MESO ETA FOR THE 1ST 48 HOURS.  ONLY MINOR TWEAKS
TO THE REST OF THE ELEMENTS WERE DONE.

...PRELIM NUMBERS...

LOZ 69/84 66/85 5423
JKL 67/83 66/85 5423

.JKL...NONE

JARVIS

=====================================================================

1110 AM MORNING DISCUSSION...
THERE WILL BE LITTLE CHANGE TO THE ZONE FORECASTS FOR THIS
AFTERNOON. THE ATMOSPHERE OVER EASTERN KY REMAINS STRONGLY UNSTABLE
LIKE YESTERDAY...AND PRECIPITABLE WATER IS A LITTLE HIGHER...IN THE
1.7 TO 2.0 INCH RANGE. THE LATEST RUC MODEL RUN SHOWS THAT A VORT
MAX...SUPPORTING CONVECTION OVER NORTH CENTRAL KY NOW...MOVES OVER
NORTHEAST KY EARLY THIS AFTERNOON. CONSIDERABLE CLOUDINESS THIS
AFTERNOON MAY INHIBIT CONVECTION TO SOME EXTENT...BUT WE HESITATE
TO LOWER THE 60 POP WE HAVE GOING. THE REMARK ON HEAVY RAIN WILL BE
TUNED DOWN A BIT TO SHOW ISOLATED HEAVY RAIN POSSIBLE. ATMOSPHERIC
CONDITIONS BASICALLY SUPPORT SLOW MOVING PULSE THUNDERSTORMS WITH
LOCALLY HEAVY RAIN. ALSO...AREA 12Z SOUNDINGS SHOW SOME INCREASE IN
LOW-LEVEL HELICITY. ANY STORM THAT MANAGES TO DEVELOP A MID-LEVEL
ROTATION COULD PRODUCE LARGE HAIL AS WELL AS DAMAGING WINDS.

SCHAUB

PREVIOUS DISCUSSION FOLLOWS:

---------------------------------------------------------------------
400 AM EDT TUE JUL 23 2002

06Z SFC ANALYSIS SHOWS LOW PRESSURE OVER THE NORTHEAST WITH A COLD
FRONT SAGGING INTO OHIO VALLEY. DEWPOINTS NEAR THE OHIO RIVER...
AHEAD OF THIS BOUNDARY ARE IN THE LOWER AND MIDDLE 70S. ON
SATELLITE...THE EARLIER CONVECTIVE COMPLEXES ALONG THE FRONT ARE
WEAKENING AND CLOUD TOPS WARMING EAST OF THE MISSISSIPPI RIVER WITH
JUST SOME LEFT OVER CLOUDS FROM THE EVENING CONVECTION OVER EAST
KENTUCKY. ON RADAR...LOCALLY IT IS NOW QUIET BUT FURTHER WEST A
COUPLE OF AREAS OF THUNDERSTORMS REMAIN AHEAD OF THE FRONT ALONG OUT
FLOW BOUNDARIES FROM THE EARLIER CONVECTION.

THE MODELS ARE IN GOOD AGREEMENT ALOFT AS A STRONG TROUGH MOVES BY
WELL TO THE NORTH IN THE WESTERLIES TODAY LEAVING BEHIND PERSISTENT
WEAKNESS IN THE SOUTHEAST AS THE FLOW BECOMES MORE ZONAL. BY THE END
OF THE WEEK THE AVN FEATURES A DISTINCT SHORTWAVE DROPPING THROUGH
THE UPPER MIDWEST AND INTO THE OHIO VALLEY...SIMILAR TO THE SOLUTION
48 HOURS AGO FOR THOSE KEEPING TRACK. THIS TOO LIFTS OUT DURING THE
WEEKEND RETURNING MORE ZONAL FLOW TO THE AREA.

FOR SENSIBLE WEATHER...THE FRONT SLOWLY SAGS THROUGH EAST KENTUCKY
TODAY AND TONIGHT WITH PLENTY OF MOISTURE AS PWS APPROACH 2 INCHES.
LIGHT WINDS ALOFT WILL MAKE HEAVY RAINS POSSIBLE FROM ANY SLOW
MOVING THUNDERSTORM OR COMPLEX OF SUCH. THOUGH...UPPER LEVEL SUPPORT
WILL BE LACKING THIS FAR SOUTH OF THE WESTERLIES. IN THIS AIRMASS
NOT MUCH UPPER SUPPORT IS NEEDED FOR SOAKING RAINS. EXPECT THE BEST
CHANCES OF SHOWERS AND THUNDERSTORMS TO DIMINISH FROM NORTHWEST TO
SOUTHEAST ON WEDNESDAY. HOWEVER...THE FRONT NEVER FULLY CLEARS THE
AREA...JUST WASHING OUT TO OUR SOUTH. THE APPROACHING UPPER TROUGH
WILL GIVE THE SFC PATTERN AN INVERTED TROUGH LOOK THURSDAY MAKING
FOR ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS...ESPECIALLY SOUTH
...BEFORE THE TROUGH AXIS SHIFTS THROUGH FRIDAY AFTERNOON. QUIETER
WEATHER WOULD APPEAR TO FOLLOW...BUT AN IMPULSE IN THE NOW ZONAL
FLOW WILL KEEP THE THREAT OF CONVECTION IN THE FORECAST FOR SATURDAY
AS WELL. THE GOOD NEWS IS THAT ALL THE CLOUDS AND SHOWERS AROUND
WILL KEEP TEMPERATURES THIS WEEK A BIT COOLER THAN THOSE OF THE PAST
FEW DAYS.

MANY DIFFERENCES IN MOS TEMPS AND POPS BETWEEN THE AVN AND NGM.
PICKED AND CHOSE ACCORDING TO THE ABOVE SCENARIO. PREFER WARMER NGM
TEMPS WEDNESDAY...BUT HIGHER MAV POPS.

AS FOR GFE/IFPS...LOADED AND TWEAKED THE MESOETA/S WINDS AND TEMPS
THROUGH 60 HOURS...HAD TO ADJUST SOME AREAS OF MODELED RAIN COOLED
MAXES TODAY AND WEDNESDAY. REST OF GRIDS INHERITED WERE HIGH QUALITY
...JUST MADE SOME SLIGHT ADJUSTMENTS TO NEW MODELS AND NDFD BLEND.

WORK ZONES AVAILABLE UNDER THE AFOS PRODUCT SDFOZFJKL BEFORE TOO
LONG.

PRELIMINARY CCF NUMBERS:
LOZ TE 088/068 083/065 084 65423
JKL TB 086/066 085/066 083 64312

.JKL...NONE

GREIF