GA PVT PLT ENCOUNTERS IFR CONDITIONS AFTER TKOF AT AKH.

Narrative

VFR FLT WAS PLANNED FROM AKH TO UPSTATE NEW YORK FOR THE MORNING OF JUN/XA/99. WX GATHERED VIA DUATS 2 HRS PRIOR TO DEP INDICATED LOW PRESSURE SYS TO THE W MOVING SLOWLY EASTWARD. CONDITIONS ALONG RTE OF FLT WERE PREDICTED TO BE MVFR WITH CHANCE OF IFR PERIODS IN THE AREA OF GASTONIA AND VFR N OF THE AREA; WITH LIGHT WINDS FROM THE S; VISIBILITY 3-6 MI AND CEILINGS MOSTLY 3000-5000 FT THE WHOLE WAY. LCL ASOS WAS CHKED 1 HR BEFORE DEP; 1/2 HR BEFORE DEP; AND JUST PRIOR TO DEP; WITH CONSISTENT READINGS OF 3 MI VISIBILITY; MIST; AND CLOUDS FEW 800 FT BROKEN 8000 FT. ON THE FINAL CHK; THE RPTED CLOUD COVER WAS FEW 800 FT; BROKEN 5000 FT. VISUAL OBSERVATION REVEALED OVCST SKIES WITH VISIBLE MIST NEAR THE SURFACE AND LIGHT WIND. UPON TKOF IT BECAME IMMEDIATELY OBVIOUS THAT THE ASOS RPT WAS DRASTICALLY INACCURATE; AS THE AIRPLANE ENTERED A BROKEN CLOUD LAYER BEFORE REACHING PATTERN ALT. AFTER A SHORT BUT UNFRUITFUL VISUAL SEARCH FOR THE ARPT; CLT APCH CTL WAS CONTACTED AND WITH THEIR AID; VISUAL CONTACT WITH AKH WAS ESTABLISHED LONG ENOUGH TO MAKE AN APCH AND LAND. A POSTFLT CHK OF THE ASOS NOW ACCURATELY REVEALED THE IFR CLOUD CONDITIONS. ESTIMATED TIME INFLT WAS APPROX 15 MINS. IN RETROSPECT; IT IS OBVIOUS THAT THE CHANGE IN THE THIRD ASOS RPT FROM THE FIRST 2 WAS THE BEGINNING OF A TEMPERED AND CHARACTERISTICALLY DELAYED RESPONSE TO RAPIDLY CHANGING WX CONDITIONS. AT THE TIME; HOWEVER; THE CHANGE SEEMED CONSISTENT WITH PREDICTED CONDITIONS AND REASONABLY CONSISTENT WITH THE PREVIOUS RPTS; AND IT WAS GIVEN NO FURTHER THOUGHT. PERHAPS CROSSVERIFYING CONDITIONS WITH OTHER AUTOMATED WX SYS; CONSULTING ANOTHER PLT OR WX BRIEFER; OR UPDATING THE DUATS RPT JUST PRIOR TO DEP WOULD HAVE PRESENTED A MORE ACCURATE WX PICTURE. BETTER TIMING SURELY WOULD HAVE HELPED. BECAUSE OF THE MARGINAL VISIBILITY OF 3 MI DUE TO LIGHT RAIN AND MIST AND THE INHERENT INABILITY OF WX DATA TO ENTIRELY REPRESENT ACTUAL CONDITIONS; THE BACKUP PLAN WAS TO FLY THE PATTERN AND RETURN TO AKH IF THINGS DIDN'T LOOK GOOD IN THE AIR. NOT BEING ABLE TO FLY A SAFE VFR TFC PATTERN BECAUSE OF A LOW CEILING WAS NOT ANTICIPATED.