Friday, October 02, 2015

Quick Look Ahead To Next Week

While the weather excitement has reached very high levels along the East Coast, I'll just take a quick look at the model forecasts for the first part of next week here in the Southwest. The plot above shows detected CG flashes over Mexico for 12-hours ending at midnight last night (from Vaisala and Atmo). Very little thunderstorm activity indicated, due to strong anticyclone centered over Sonora, along with very warm middle-level temperatures.

The GFS model continues very similar to the ECMWF currently and digs the short wave currently over western Canada southward across California. The 500 mb forecast shown above is from the 00 UTC run of the GFS and is of 500 mb heights, winds, and temperatures valid at 12 UTC next Tuesday morning (October 6th). At that time model forecasts a closed low to be centered over Las Vegas with temperatures near -20 C, and a range across Arizona of nearly 10 C from southeast to northwest - quite a significant change. The closed low pulls higher PW northward from the GoC and northwestern Mexico, resulting in a significant precipitation event for all of the Southwest.

The 00 UTC GFS forecast of total precipitation through 12 UTC next Wednesday morning is shown above. The model forecasts quite some event for much of the west - but out east, even though model keeps Hurricane Joaquin off shore, the forecast  rainfall over the Carolinas is just huge - max contour on the forecast is for 15-20 inches!

The 00 UTC forecast from the WRF-GFS (below) for same period as above shows the small scale details, which indicate both a strong west to east gradient across southern Arizona and also a donut hole minimum over eastern Pima County. The WRF maximizes the event over New Mexico and from the White Mountains westward along the Rim Country. Time will tell.

No comments:

Post a Comment