TAMDAR Discussion Board

TAMDAR improved RUC moisture profile

Posted By: Lyle.Alexander
Date: 3-May-05 2221Z

Today we have a w/nw cyclonic flow across the Ohio Valley. Widespread stratocumulus developed early this afternoon. There are no reports of precipitation but some icing, mostly light. Ceilings are running in the 6-8 thousand foot range. At 20Z, SDF reported 80 OVC and CRW had 70 BKN. There was a TAMDAR report at CRW at 2001Z and a non-TAMDAR vapor equipped report at SDF at 2027z. Both SKEW-Ts were strikingly similar with surface T of 10C and Td of -5C. They both reached or nearly reached saturation briefly at about 720 millibars. Checking model soundings, the RUC2 at SDF had no less than a 5C degree spread while the RUC dev2 had a shallow layer of saturation at 760 millibars. The Mesoeta had a small spread at SDF at around 800-850 millibars, too low considering the cloud layers and aircraft reports. At CRW, both RUCs had a layer of saturation between 850 and 750 millibars, a little low in altitude according to the TAMDAR report but close to what the ceilings were in the area. However, the temperature at 700 millibars was much more accurate with the dev2. The aircraft reported -12.7, the dev2 -11.1 and the RUC2 was -8.2. Lyle