Tuesday, February 25, 2014
Dreary Morning Here In Tucson
Several weak short waves at 500 mb have been materializing within the low-latitude branch of the flow that is undercutting the West Coast ridge. We had some light sprinkles around yesterday and it appears there will be even more shower activity today. View of Catalinas (above) this morning shows thick, high clouds with some scattered middle clouds present. The total PW product from CIMSS at Univ. of Wisconsin (below, for 11 UTC this morning - February 25th) shows a broad plume of higher PW approaching northern Baja from low latitudes. Some of this increased moisture will clip southeastern Arizona today, producing an increase in light showers.
The early WRF-NAM composite radar echo forecast, from Atmo, for 4 pm this afternoon indicates widespread but light radar echoes. The WRF-NAM forecast of precipitation through midnight tonight (below) indicates that most of the echoes in the model forecast remain aloft, with rainfall reaching the surface most likely to our southeast. A stronger system may impact our area on the weekend, so something to keep an eye on.
Posted by Bob Maddox at 6:53 AM