Severe Thunderstorm Warning 142, NWS Jackson, KY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
120 PM EST SAT NOV 24 2001

AN ACTIVE WEATHER PATTERN FOR THE NEXT SEVERAL DAYS. SEVERAL FCST
CONCERNS IN BOTH THE LONG TERM AND SHORT TERM. MAIN SHORT TERM
PROBLEM IS WITH TONIGHTS WX...SVR CHANCES/WINDS/TIMING OF ENDING OF
THE PCPN IN THE MORNING. MAIN LONG TERM PROBLEM IS THU NIGHT/FRI AND
THE POSSIBILITY OF MIXED OR FROZEN PCPN.

SO FAR TODAY...DOWNSLOPING WINDS HAVE BEEN WINNING THE BATTLE.
HOWEVER AS THE BNDRY MOVES CLOSER THE DYNAMICS WILL OVERCOME THE
DOWNSLOPE EFFECT. SFC CHART SHOWING COLD FRONT ACRSS EASTERN MO AND
AR DOWN INTO FAR E LA. WARM FRONTAL BNDRY HARD TO DISCERN BUT
APPEARS TO BE ACROSS W-CNTRL KY AND TN. WRAPPED UP LOW SFC-ALOFT
NEAR OMA. 55 TO 60 KT 8H JET PUNCHING INTO CNTRL TN/KY. STRONG PRESS
GRADIENT BUT WINDS THUS FAR NOT MIXING DOWN OVER E KY. SLIGHT
INVERSION ON FCST SOUNDINGS. FOR TONIGHT MAIN CHALLENGE WILL BE SVR
CHANCES AND HOW MUCH OF THE STRONG WINDS ALOFT WILL MIX DOWN. HAVE
SEEN THIS BEFORE WITH 60 KT JET RIGHT ABOVE THE DECK ALONG WITH A
VERY SATURATED SOUNDING AND ALL WE GOT OUT OF IT WAS RAIN AND 8-10
KTS OF WIND. HAVE TO WONDER IF THIS EVENT WONT BE THE SAME. WILL
HOLD OFF FOR NOW ON ANY WIND ADVISORIES BUT SOME GUSTY WINDS WITH
EMBEDDED TSRA A DECENT BET. SVR CHANCES DONT LOOK ALL THE PROMISING.
TIMING IS WRONG AND THE BEST DYNAMICS SEEM A BIT OUT OF PHASE. FEEL
THERE COULD BE A FEW SVR EARLY-EARLY EVENING WHEN THE ACTIVITY FIRST
ENTERS THE WESTERN CWA. WILL NOT MENTION TIMING IN THE ZONES AS AT
LEAST SOME RAIN SHOULD GO ON ALL NIGHT. NEAR 100 POPS. GUIDANCE
NUMBERS LOOK CLOSE.

WILL HAVE TO MAKE SOME MENTION OF LOW CHC SHRAS IN THE MORNING AS
PCPN MAY LAST JUST PAST 12Z ESP IN THE EASTERN ZONES. CLOUDS DECR
THRU THE DAY AND HIGHS GET BACK UP INTO THE 60-65 RANGE. WILL GO
MCLR TOMORROW NIGHT WITH LOWS MID 30S VALLEYS/LOWER 40S RIDGES.

HIGH PRESSURE AND SHORT WAVE RIDGE TO DOMINATE THRU MOST OF MONDAY.
CLOUDS INCR MONDAY NIGHT AND WILL MAKE MENTION OF SHRA. SHOWERS LOOK
LIKELY DURING THE DAY ANYHOW ON TUESDAY.

FOR WEDNESDAY THROUGH SATURDAY...AS TROFF ALOFT WORKS EAST OUT OF
THE ROCKIES...TEMPS SLIDE DOWNWARD THRU THE PERIOD. NOT VERY
CONFIDENT AT ALL IN THE MODEL SOLUTIONS. 12Z AVN IS EVEN FASTER AND
STRONGER WITH DEVELOPING SFC LOW OVER ATLANTA GA BY 12Z THU. MRF
TAKES THE FRONT UP THE SPINE OF THE APPALACHIANS...WHICH IS A
DANGEROUS TRACK FOR US. THICKNESS SCHEMES AND 8H TEMPS WOULD
INDICATE ALL RAIN EARLY ON...BUT CHANGING TO SNOW AS THE EVENT
UNFOLDS BY FRIDAY ON STRONG BACKSIDE/WRAP AROUND. 23/12Z ECMWF LOOKS
LIKE IT CAME FROM ANOTHER PLANET COMPARING IT TO THE MRF.
HOWEVER....23/00Z MRF LOOKED VERY SIMILAR TO THE 23/12Z ECMWF....AND
THE 12Z AVN RUN TRYING TO LEAD SOME CREDENCE TO THE MRF. ITS HARD TO
TELL IF THE AVN/MRF ARE OFF ON A WILD TANGENT OR NOT. I WOULD REALLY
LIKE TO SEE THE 24/12Z ECMWF AND THE PMDEPD DISCUSSION BEFORE MAKING
ANY SORT OF FINAL DECISIONS ON PCPN TYPE WORDING. IN ANY
EVENT...SEVERAL CHANGES WILL HAVE TO BE MADE IN THE DATABASE
THROUGHOUT THE EXTENDED PACKAGE. WILL TREND TEMPS LOWER AND POPS A
LITTLE HIGHER. WILL HAVE TO MAKE LAST MINUTE DECISION ON PCPN TYPE
THUR NIGHT/FRI OR HOW HARD TO EVEN HIT THE POPS FOR THAT MATTER.

NGM AND AVN MOS SIMILAR AND WONT STRAY FAR. THANKS TO CRW FOR
COORDINATION.

.JKL...NONE.

HALL