More Big Model Flip-Flops

The last two days, there have been more flip-flops on the models for next Sunday and Monday than you can find on a sunny, summer beach. Pass the Advil; I have a headache.

If you did not read yesterday’s post, perhaps you should go back and do so before reading this one. It would give you a better feel for how things have transpired over the last two days.

Starting with last night's model runs, the GFS and European both went back to a strong, digging inside slider coming south from the Northwest into the Southwest Sunday night and Monday. Today’s 12Z runs have at least agreed with that and other models such as the UKMET and GEM are in the same ballpark. You will see there are differences, but mostly in timing, with the European being 6 to 8 hours faster than the GFS. Here are the current forecast 500 mb maps for 12Z Monday.

GFS:

European:

Setting aside the timing problems, these models would bring more significant weather to Nevada, California, Arizona and parts of Utah than yesterday’s models. Showers of rain and snow with crashing snow levels will be likely, especially from near the track of the low on east and south. There even could be scattered thunderstorms. Strong winds would be likely in the deserts of the Southwest with areas of blowing sand and dust. It would also be quite windy along the California coastal areas and just plain windy elsewhere.

Expect at least some snow in the Sierra, in parts of Nevada and also in the mountains of Arizona. Snow would also fall in Utah, especially in the Wasatch. I would prefer to wait a little to give specifics on amounts just because I would like to see another set or two of runs. However, if you have plans to go to any of the mountains, plan for colder weather with the potential for snow.