Thursday, November 1, 2012

What Are The Models Saying This Winter? Part 3

Yes, you guessed it. Another sequel to show you what the models are thinking for this upcoming winter. If you want to keep these coming (I have several other models), comment below and tell me so! Let's get right into the models.

This is the precipitation (top) and temperature (bottom) forecast for this winter off the NASA model, a model run by the folks at NASA. This model is showing a very wet East Coast and Southeast, as well as above normal precipitation anomalies in Alaska. However, for the Northwest and northern Plains, a drier scenario is waiting. As for temperature, a warmer than normal airmass is being forecasted across Alaska and northern Canada. In the Lower 48, another warm air mass controls the East Coast and Midwest into the Southeast. The Northwest, however, gets a chill for the winter.

This forecast is puzzling. I'm seeing an above normal temperature anomaly in the northern reaches of Canada. Typically, this can indicate a negative Arctic Oscillation, or AO. This negative AO helps to bring cold air south into the nation. However, the NASA model prefers a warm East Coast. While this is completely possible, the overall scenario seems a little "off" to me. Also, the NASA model is not known for its verification, which isn't the best. That said, I don't think I want to side with this model at the moment.

This next model's precipitation (top) and temperature (bottom) forecasts are from the NCAR long range model, developed at the NCAR facility. This model is also not known for being the best when it comes to its forecasts verifying, but the NCAR long range model may have some sense in this forecast. I want to start in the temperature department, where above normal temperatures are displayed in Alaska and the Greenland region. The above normal temperatures in Alaska would lead to a likely ridge in the area, which provokes cold air to be sent south. This could be encouraged by warm northern Atlantic waters (possibly a negative NAO pattern), which leads us to the NCAR's forecast of well below normal temperatures in much of the nation. In the precipitation department, a very dry Alaska (symptom of ridging) and West Coast are observed. This dry spell extends into the Plains, although much of the East US is well above normal for precipitation. The factors working together spell out a pretty logical forecast. If this were to verify, I can't say I would be surprised. I do support some portions of this forecast, mainly the temperature forecast.

Look for more 'What Are The Models Saying This Winter?' posts in coming days!



Logan said...

I would love for you to keep this coming, you are great with these models! :)


Anonymous said...

Do think central California will have a drought this season?

Anonymous said...

Keep the models coming. Even though I don't like the second models forecast it does appear that pattern exists already to an extent. Down here in central New Mexico, we are heading for the second year in a row with well below average precip.