The good, the bad, and the ugly

Posted on: 10:39 pm, February 13, 2014, by

Terry Swails Weather Blog

Before I begin this post, I want to qualify that this is something that popped up on the U.S forecast model today that I found very interesting. You won’t see this anywhere else. It’s not a forecast, just a models interpretation of what might lie ahead. This is behind the scenes information that I have access to. Please take it with a grain of salt. The specific numbers are not important, what is are the trends. No model at this distance can precisely nail the temperature or snowfall amounts. However, when put in proper perspective the data can yield important clues to the pattern that is likely to develop in the 2 week period.

Just like in the movies, this is a bit of fantasy land with a touch of reality. That’s what long range forecasting is all about. Welcome to the world I live and work in.

First, let me put up the GFS meteogram for the next 7 days. In my mind there is nothing shocking about this and the warming reflected is now showing up in Midwest forecasts across the board. I’ve been talking about it for nearly a week because of data like this.

In the top bar note the forecast highs of 45, 46, and 54 Feb 19-21st. That looks strong to me. There is also about 1/2″ of rain shown between the 18th and 21st. I think that’s also in the ballpark. I would run with this forecast. It’s well supported.

QUAD CITIES METEOGRAM FEB. 13-18th
QUAD CITIES METEOGRAM FEB. 13-18th

Now, here comes the boom! The GFS shows the pattern flipping again around the 22nd of February. This has some merit as the AO and NAO are shown going negative. The PNA is also inching into positive territory. The warm waters of the N. Pacific still exist so it seems reasonable to assume the cold that has dominated the winter will make another comeback. This is late season cold so it won’t be as bad as recent outbreaks but believe me it will be plenty frisky. There is one morning where I’ve highlighted the GFS low of 21 below around the 26th.

QUAD CITIES METEOGRAM FEB 21-MARCH 1ST
QUAD CITIES METEOGRAM FEB 21-MARCH 1ST

Here’s the part that people love to run with and tend to panic over. Don’t because this is the area where skill level is the lowest and model accuracy is least likely to occur! There’s 2 big ticket snowstorms showing in this 7 day period and precip totals at the end of it total 2.7o”.  The GFS shows this as all snow and actually has a a snow depth of 24″ for the Quad Cities March 1st.

Do I expect this? Absolutely not. As I indicated earlier the only thing that concerns me are the trends. The numbers mean very little other than they are off the charts. However, if the trends are correct, we will be back to cold and snowy weather by the last week of February and early March. Watch the trends, that’s all I’m saying! Roll weather…(TS)