Friday, February 09, 2018

Precipitation Chances Back In Forecast

Photos from Jack Hales webcam wall this morning: above sunrise over the Teton Valley in Wyoming. Down at the bottom is a view of a very foggy LAX airport.

As a short wave passes by to our northeast tomorrow, winds become gusty from the southwest. The WRF-GFS forecast above (from Atmo's 06 UTC run on the 1.8 km grid) is for 10-m winds at 4:00 pm MST tomorrow afternoon.

Next week the global models are in good agreement out through about 132-hours as the following short wave digs south-southwest across the West, ending up as a closed low west of San Diego. The forecast for 500 mb shown above is from the 00 UTC WRF-GFS on the 5.4 km grid and is valid at noon on February 14th. At that time the model forecasts the cold low to be due west of San Diego, in a good position to pull subtropical moisture northward toward Arizona and southern California. 

The 00 UTC spaghetti plot for 500 mb from the GEFS (below valid at 5:00 am on the 14th) shows reasonable agreement among all the members, but also with a bit of spaghetti around the closed low.

After 132-hours the models diverge some, with different solutions for the evolution of the closed low and the northward extent of the subtropical moisture intrusion - we'll just have to monitor all this next week. However, this morning's NWS forecast indicates precipitation chances at the airport next Wednesday and Thursday reaching as high as 40%.

No comments:

Post a Comment