Severe Thunderstorm Warning 15, NWS Jackson, KY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
210 PM EDT WED APR 17 2002

SUMMER LIKE WEATHER FOR A FEW MORE DAYS. COOLER TEMPS OVER THE
WEEKEND AND INTO NEXT WEEK. SHORT TERM AND LONG TERM PROBLEMS STEM
AROUND PCPN CHANCES AND TIMING OF SYSTEMS.

SHORT TERM MODELS IN FAIR AGREEMENT TODAY WITH SYNOPTIC SCALE
FEATURES BUT DIFFER IN THE DETAILS. MODELS DO AGREE IN SLOWING DOWN
THE MAIN FRONT ON FRIDAY AND ITS ASSOCIATED SHRA/TSRA.

SHORT TERM SENSIBLE...FEW SHRAS TRYING TO POP UP OVER CWA ATTM WITH
SOME TSRA OVER FAR WESTERN VA AND WV AND E TN. SKY COVER HAS INCR
ALMOST TO MC IN ADVANCE OF VORT MAX NEAR MEM. MODELS SLOWLY MOVE THIS
FEATURE EAST OVERNIGHT AND WEAKEN IT. DESPITE WEAKENING TREND FEEL
ENUFF INSTABILITY AND SOME FORCING AROUND FOR A LOW CHC (30) POP
TONIGHT...MAINLY BEFORE MIDNIGHT TYPE OF WORDING. TEMP REGIME VERY
SIMILAR TONIGHT TO THE LAST FEW NIGHTS AS AIRMASS REGIME IS THE
SAME. JUST ENUFF TEMP DIFFERENCES TO BREAK OUT A VALLEY/RIDGE SPLIT
AGAIN TONIGHT.

ETA MOS HITS THE POPS A LITTLE HARDER TOMORROW THAN THE NGM/AVN WITH
THE NGM THE DRIEST. STILL DONT SEE MUCH LIFT/FORCING AROUND BUT WITH
DECENT RH AND AFTERNOON HEATING WILL CARRY A SLIGHT CHC POP. HIGHS
AGAIN IN THE 80-85 RANGE MOST OF THE CWA. WILL GO PC TOMORROW NIGHT
WITH LOWS GENERALLY 57-62. FRONT SLOWLY MOVES INTO THE AREA FRIDAY
AFTERNOON/EVENING. AVN HAS SLOWED DOWN THE FRONT THE MOST BUT ALL
MODELS ARE SLOWER THAN PREV RUNS. WILL UP POPS TO LIKELY IN THE
DATABASE AND GO WITH AFTERNOON TYPE WORDING. LIKEWISE WITH THE
SLOWER MOVEMENT HAVE INCR POPS FRIDAY NIGHT INTO THE LIKELY RANGE.

WILL CONTINUE WITH CHC POPS ON SAT WITH THE FRONT STILL IN THE AREA.
AVN ARGUES FOR LIKELY POPS BUT NOT TOTALLY BUYING INTO THAT
SOLUTION. ON THE OTHER HAND...EXTENDED ETA MODEL PUSHES THE BNDRY
FURTHER AWAY AND ARGUES FOR ALMOST NO POPS AT ALL. WENT WITH PC ON
SAT NIGHT (LOWERED POPS) BUT NOT HIGHLY CONFIDENT AT THIS TIME.

EXTENDED...(SUN-WED) SIMILAR TO YESTERDAY...THE MRF AND ECMWF/UKMET
AND ENSEMBLES STILL DIFFERENT IN STRENGTH AND TIMING OF SYNOPTIC
FEATURES. STUCK WITH CHC POPS ON SUN AS ANOTHER WAVE MOVES ALONG THE
FRONT AND MOVES TOWARD THE AREA. KEPT CHC POPS GOING ON MONDAY...BUT
WILL GO WITH MAINLY DURING THE DAY OR MORNING WORDING. I AM BOTHERED
BY THE LARGE DIFFERENCES BETWEEN THE VERY WET LOOKING AVN AND THE
VERY DRY (FOR HERE) LOOKING ETA. ETA MODEL KEEPS ALL THE PCPN IN TN.
WILL HAVE TO CONTINUE TO FINE TUNE AS WE GET CLOSER IN. WILL STICK
WITH PC ON TUE WITH BIG SFC HIGH DOMINATING. HAVE INTRODUCED CHC
POPS FOR WED. AS FOR TEMPS...WENT CLOSE TO ENSEMBLE MEAN GUIDANCE
RATHER THAN STRAIGHT MEX GUIDANCE..WHICH PREEPD (NCEP) STRONGLY
FEELS IS AT LEAST 4 DEGREES TO COLD THRU THE PERIOD. STILL IT WILL
BE QUITE A BIT COOLER THAN IT HAS BEEN THIS WEEK-BUT VERY CLOSE TO
SEASONAL NORMALS.

IFPS/GFE...DATA BASE IN REALLY GOOD SHAPE OVERALL. AS NOTED
ABOVE...RAISED POPS ON FRIDAY AND FRI NIGHT. TWEAKED HIGH TEMPS DOWN
A LITTLE HERE AND THERE. RAISED POPS JUST SLIGHTLY ON SUN. ADDED NEW
DAY 7. DUE TO NUMEROUS SLOS (SPONTANEOUS LOG OUTS), DID NOT SPEND
MUCH TIME TODAY WITH 1 HR WEATHER/POPS...BUT DID WORK ON THEM SOME
IN THE TEMPORAL EDITOR.

ETA/NGM/ETA GUIDANCE NUMBERS REAL SIMILAR. WILL USE A BLEND WHERE
DIFFERENCES DO OCCUR.

WORK ZONES OUT BEFORE TOO LONG UNDER SDFOZFJKL. COORDINATION
WELCOME.

.JKL...NONE.

HALL