FXUS63 KLMK 280211
AFDSDF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
1010 PM EDT FRI SEP 27 2002
QUESTION OF THE HOUR IS THE FOG POTENTIAL FOR LMK CWA OVERNIGHT.
ATTM, WINDS HAVE ALREADY GONE BELOW 5KTS IN LOWEST FEW HUNDRED
METERS AGL AS OF 1Z. THERE ARE SOME RESIDUAL CLOUDS ~6KFT OVER SERN
1/2 OF CWA WHICH APPEAR TO BE ASSOC WITH SUBTLE 850MB DEF ZONE SEEN
IN 21Z RUC40 FCST, AND SHOULD MAKE SLOW PROGRESSION SE NEXT FEW
HOURS. HOWEVER, THESE CLOUDS WOULD REPRESENT A SIG LIMITING FACTOR
FOR FOG SHOULD THEY HANG AROUND ALL NIGHT! SFC TD'S REMAIN FAIRLY
HIGH, IN MID/UPPER 60S AND FRANKFORT HAS ALREADY DROPPED TO 2SM BR
IN LAST HOUR, WHILE 3 TAF SITES REMAIN AOA 10SM. CALLING AREA AWOS
SITES ALSO INDICATES VISIB ATTM REMAIN UNRESTRICTED, BUT T-TD
SPREADS ARE BELOW 5F.
OTHER INGREDIENT TO CONSIDER IS AXIS OF HEAVY RAINS LAST NIGHT WEST
OF I-65 HAS SATURATED THE SOILS, AND 18Z ETA BUFKIT DATA INDICATES
THAT SOME EVAPORATION OF THIS MOISTURE BACK INTO NOCTURNAL BOUNDARY
LAYER WILL OCCUR OVERNIGHT. 20KM RUC ON WEB DOES HAVE MOST OF LMK
CWA AOB 1/2SM FG BY 12Z/SAT, AND THIS MODEL HAS EXHIBITED SKILL WITH
RADIATIONAL FOG IN THE PAST. CONVERSELY, NORMAL SETS OF MOS GUIDANCE
ARE LACKLUSTER WITH FOG, EXCEPT MAV AT KHNB IN SRN IND WHICH HAS CAT
1 CIG BY 12Z/SAT.
PENDING EXAMINATION OF 2Z METARS AND AWOS DATA, AT THIS POINT I WILL
LIKELY BUMP UP WRN 1/2 OF CWA TO "AREAS OF FOG" OVERNIGHT, SOME OF
IT COULD BE "LOCALLY DENSE" ESP IN VALLEY AND RIVER BOTTOM
LOCATIONS. THE ERN ZONES HAD SIG CLOUD COVER TODAY KEEPING MAX TEMPS
QUITE COOL, BUT PBL WINDFIELD WILL BE HIGHER OVERNIGHT SUGGESTING
MORE OF A LOW STRATUS THAN SURFACE FOG. BUT TO PLAY IT SAFE AND
SINCE ASOS OBS THERE ALREADY GOING DOWN, THINK THERE'S STILL DECENT
THREAT OF FOG SO I'LL GO "AREAS" THERE AS WELL. I'LL ALSO UPDATE THE
ONGOING HAZ WX OUTLOOK (SPSSDF) WITH RESPECT TO POSSIBLE FOG.
THX PAH FOR COORD CALL. .SDF...NONE.
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