Sunday, March 01, 2015

Quick Look At Guidance Products/Forecasts

Only time for quick look at a couple of products re upcoming weather event. The graphic above is the QPF guidance from NWS WPC valid from 12 UTC this morning (March 1st) through 12 UTC Wednesday morning. The WPC's forecast amounts continue to decrease for southeastern Arizona as the event draws closer in time. The event, in their forecast, continues to be focused from San Diego across northern Arizona and into western Colorado. There is a secondary maxima forecast for northern Mexico.

For comparison I'll show the higher spatial resolution forecasts from the 00 UTC run of the WRF-NAM at Atmo. Above is the forecast on the 5.4 km grid through 12 UTC on March 4th and it is very similar to the NWS WPC guidance product above - almost looks as if the forecasters back there could have used this WRF forecast for their guidance.

Below is the same forecast but for the 1.8 km grid. Certainly the trend is not good for rain at lower elevations, with amounts over southeastern Arizona now focused on higher elevations in Pima County.

However, the event is still a day or so away (WRF forecasts main shower bands in Tucson area to occur tomorrow afternoon and evening). The soundings forecast for tomorrow afternoon for TWC are similar to other soundings this winter that produced nice amounts of rain - so we will need to keep an eye on tomorrow's evolution of the setting.

No comments:

Post a Comment