Today’s 12z GFS was catching onto the thinking of the past couple of weeks that the jetstream would continue to get stronger in January and push further South. It showed the ridge shifting South with storms beginning to push further South next week with continuous storms hitting for about a week. At the same time the Euro came out showing the opposite with the trough digging north of Hawaii and starting all over again with the ridge building up the West Coast.

Which weather model is correct? Probably neither as one tends to be to fast with pattern changes and the other too slow. A lot of weathermen like to blend the two. Most weathermen are having a hard time with the models this year as they are flip flopping more than usual trying to get a handle on everything going on in the pattern. This evening’s 18z GFS was more of a blend between the other two runs showing the trough North of Hawaii next week and ridge up the West Coast but then retrograding the ridge to allow storms in for week 2.

Some people have been complaining that the storms are always two weeks away. That is not true because while it was stormy in November I kept saying the dry conditions were coming in 2 weeks. We have to look ahead as far as possible at signs of a potential pattern change in a long dry spell like this. We haven’t measured snow now in over 5 weeks.

The PNA and NAO are forecasted to go neutral over the next 2 weeks. We need the PNA to keep going into negative territory by mid-month. With the neutral telelconnections the MJO should have more of an affect on the pattern. We will have to see if it continues to progress into the Pacific this week and then if the ridge then retrogrades back from the coast week 2.

The storms hitting the Pacific NW this week don’t look like they will really bring any precip at all with the best chance of a sprinkle or a flake on Friday. Next week the storms for the 2nd and 5th will try to dig a little further South but the ridge should keep the first one to the North and the second one could have a bit more success in bringing some light precip. Then it looks like the pattern slows with the trough digging North of Hawaii and in the East, with the ridge building up the West coast again just like the past few weeks.

Week 2 is when the MJO would start to have an affect on the pattern if it keeps moving East. It is also when most of the models suggest the ridge could retrograde back towards 140w in the Pacific letting in some storms from the Northwest. Mid-month would be the best chance for the PNA to go negative. Hang in there….BA

Filed under: Home

Like this post? Subscribe to my RSS feed and get loads more!