Severe Thunderstorm Warning 123, NWS Jackson, KY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
302 PM EDT FRI JUN 14 2002

---FORECAST ISSUES---

TEMPS/CLOUDS AND ITS AFFECT ON AFTERNOON TEMPS IN THE SHORT TERM ARE
THE MAIN FORECAST CHALLENGES FOR THIS FORECAST PACKAGE.

---MODELS/ZFP---

CLOUDS CONTINUE TO MOVE EAST WITH CLEARING LINE JUST WEST OF OUR
CWA.  SHOWERS AND A FEW THUNDERSHOWERS CONTINUE TO MOVE ACROSS THE
AREA AND SHOULD BE OUT OF HERE BY SUNSET.  OTHER CONVECTION FIRING
UP ACROSS NORTHERN INDIANA WITH H5 WAVE SWINGING AROUND THE BASE OF
THE CLOSED LOW OVER THE GREAT LAKES.  COLD AIR ALOFT AND SURFACE
HEATING GENERATING NUMEROUS LOW TOPPED CONVECTION.

FOR TONIGHT...WILL CARRY A SLIGHT CHANCE OF POPS EARLY THIS EVENING
AS TROF SWINGS THROUGH THE REGION. PARTLY CLOUDY SKIES SHOULD BE THE
RULE THROUGH SATURDAY WITH COOL AFTERNOON READINGS ABOUT 5 TO 7
DEGREES BELOW NORMAL.  TEMPS WILL WARM UP A LITTLE MORE ON SUNDAY.
ETA/META/AVN SOLUTIONS SHOWING ANOTHER LITTLE BAND OF MOISTURE AND
PRECIP TRANSVERSING THE REGION ON SUNDAY AFTERNOON.  FWC POPS ARE
NIL WITH THIS BUT ETA/AVN SHOWING CHANCE POPS.  NOT REAL CONFIDENT
WITH THIS PRECIP EVENT JUST YET...BUT PLAN ON RUNNING SLIGHT CHANCE
POPS OVER THE NORTH AND CARRYING A 30 POP ACROSS THE SOUTH FOR
SUNDAY AFTERNOON.  AFTER THAT QUIET WEATHER SETTLES BACK INTO THE
REGION FOR SUNDAY NIGHT AND MONDAY.  AGAIN MOS GUIDANCE NUMBERS IN
GENERAL AGREEMENT AND A BLEND WILL BE USED.

---EXTENDED---

UPPER AIR PATTERN IN THE FIRST PART OF THE EXTENDED STARTS OFF
FAIRLY AMPLIFIED AND BEGINS TO SLOWLY DEAMPLIFY WITH TIME.  ALTHOUGH
A FEW OF THE ENSEMBLE MEMBERS SUGGEST A CONTINUED AMPLIFIED UPPER
LEVEL PATTERN. LARGE TROUGH LOCATED IN THE EAST U.S. IS FORECAST TO
BE SHUNTED OFF TO THE EAST AS NEW TROF DIGS IN ACROSS THE PACIFIC
NORTHWEST.  BY DAYS 5 AND 6...UPPER LEVEL PATTERN BECOMES A FAST
ZONAL PATTERN WITH EMBEDDED PURTURBATIONS WITHIN THE FLOW.  THIS
KIND OF PATTERN OFTEN PRODUCES TIMING DIFFERENCES FROM MODEL RUN TO
MODEL RUN...SO CONFIDENCE IN THE OVER SCHEME OF THINGS IS LOW AT
THIS POINT.  AS FOR THE DETAILS TO THE EXTENDED FORECAST...TUES/WED
LOOK TO BE PARTLY CLOUDY AND COOL IN THE WAKE OF THE LARGE TROF
MOVING OFF THE EAST COAST. AT THE SURFACE HIGH PRESSURE BUILDS IN
AND DRIFTS OFF TO THE EAST BY THURSDAY AND FRIDAY.  THIS WILL RESULT
IN MORE OF A SOUTHWEST FLOW ACROSS THE AREA WITH INCREASING MOISTURE
BEING DRAWN UP FROM THE GULF.  AT THIS POINT...PLAN ON RUNNING A 30
POP FOR THU/FRI MAINLY FOR AFTERNOON/EARLY EVENING CONVECTION.  AS
FAR AS TEMPERATURES GO...TEMPS WILL START OFF COOL/SLIGHTLY BELOW
NORMAL FOR TUES/WED...AND THEN BEGIN TO QUICKLY MODERATE TO SLIGHTY
ABOVE NORMAL FOR THU/FRI WITH AFTERNOON HIGHS IN THE LOW TO MID 80S.

---NDFD GRIDS---

SHORT TERM: RELOADED 1 HOUR T/TD AND SFC WINDS FROM THE MESO ETA.
MADE SOME TWEAKS TO MAX/MIN TEMPS AND ADJUSTED POPS TO REFLECT
UPCOMING FORECAST.

EXTENDED: ADJUSTED MAX/MIN TEMPS SLIGHTLY.  RELOADED WINDS.  MADE
SOME ADJUSTMENTS TO SKY COVER AND POPS.

---PRELIM NUMBERS---

LOZ 55/74 55/76 0003
JKL 56/74 57/76 0003

.JKL...NONE.

JARVIS