Pilot reporter claims inaccurate WX at dfw from ASOS equipment.

Attributes
ACN	344656
Time
Date	199608
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : dfw
State Reference	TX
Altitude	msl bound lower : 11000 msl bound upper : 18000
Environment
Flight Conditions	Mixed
Light	Night
Aircraft 1
Controlling Facilities	tracon : dfw
Operator	common carrier : air carrier
Make Model Name	Fokker 100
Operating Under FAR Part	Part 121
Flight Phase	descent : approach landing other
Route In Use	arrival other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	344656
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	inflight encounter : weather other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : unable
Consequence	Other
Supplementary
Air Traffic Incident	other
Situations
Airport	other physical facility

Narrative:

ASOS WX reporting clear. Actual WX was heavy overcast at 11000 ft AGL with tops above FL180 and 50 percent coverage of moderate rainshowers and thunderstorms along with turbulence, windshear and virga. Sky condition clear does not come close to accurately describing what the WX situation was. ASOS reports sky condition clear when there is a mid level heavy overcast with rainshowers and thunderstorms, windshear, turbulence and virga covering the entire area. Our departure was impacted by lots of WX that we had to deviate around painting on the radar, and turbulence and icing conditions in the clouds. Sometimes the only WX information available to us when departing an outstation is a string of these ASOS WX reports. When there are numerous reports of sky conditions clear, or clear below 12000 ft -- it gives a dangerously misleading impression that the WX is very good, when in fact it might be very bad.

Original NASA ASRS Text

Title: PLT RPTR CLAIMS INACCURATE WX AT DFW FROM ASOS EQUIP.

Narrative: ASOS WX RPTING CLR. ACTUAL WX WAS HVY OVCST AT 11000 FT AGL WITH TOPS ABOVE FL180 AND 50 PERCENT COVERAGE OF MODERATE RAINSHOWERS AND TSTMS ALONG WITH TURB, WINDSHEAR AND VIRGA. SKY CONDITION CLR DOES NOT COME CLOSE TO ACCURATELY DESCRIBING WHAT THE WX SIT WAS. ASOS RPTS SKY CONDITION CLR WHEN THERE IS A MID LEVEL HVY OVCST WITH RAINSHOWERS AND TSTMS, WINDSHEAR, TURB AND VIRGA COVERING THE ENTIRE AREA. OUR DEP WAS IMPACTED BY LOTS OF WX THAT WE HAD TO DEVIATE AROUND PAINTING ON THE RADAR, AND TURB AND ICING CONDITIONS IN THE CLOUDS. SOMETIMES THE ONLY WX INFO AVAILABLE TO US WHEN DEPARTING AN OUTSTATION IS A STRING OF THESE ASOS WX RPTS. WHEN THERE ARE NUMEROUS RPTS OF SKY CONDITIONS CLR, OR CLR BELOW 12000 FT -- IT GIVES A DANGEROUSLY MISLEADING IMPRESSION THAT THE WX IS VERY GOOD, WHEN IN FACT IT MIGHT BE VERY BAD.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.