HMT Daily Wx Discussion & Forecast: Mon. 05-Mar-2007
An ill-defined comma-cloud shield associated with the ejecting weak subtropical shortwave trough is presently exiting CA. There is some remnant midlevel cloudiness across the Sierras that should depart in the post-wave subsidence as the day progresses. Only a couple of precip gauges in the Sierras recorded very light amounts during the passage of this wave. Shortwave ridging tonight and tomorrow will keep the area dry.
The suite of operational models all depict a fairly weak shortwave trough clipping the northern Sierra on Wednesday and Wednesday night. The dynamics and orographics with this system will be weak, and the available moisture content modest, during passage of this wave and its associated dying cold front. It may be tough to squeeze more than ~0.5 inch of liquid in the ARB with this “storm.” Snow levels will be moderately high – in the 6-8 kft range.
A flat ridge over most of CA toward the end of the week and beyond will likely keep significant precip north of the ARB, although extreme northern CA may have some precip in the extended.
Paul Neiman
NOAA/ESRL/PSD2