More Ups and Downs To Come; Fewer Extremes but…March 14th, 2014 at 9:39 pm by Don Paul under 4 Warn Weather
STILL Cooler/Colder than average in the mean. During the week of March 17th, we’ll start on a cold note, with some moderation on Tue-Wed ahead of a storm system crossing the northern Great Lakes. However, the lows and highs this week appear to be of a lesser amplitude. It won’t be as warm on the warmer days, and it won’t be as cold on the colder days…a little bit of a smoother ride. The Great Lakes storm will be vigorous as we move toward Wednesday night, but its cold front won’t be tapping much Gulf moisture and the low will be too far north to present us with that much rain or snow. Behind, some Pacific-moderated colder air will take us back to the 30s on Thursday-Friday. Another system could bring us some mixed precip or rain by later Saturday, with cooler air returning by Sunday or Monday the following week. After that, week 2 looks smoother with a more zonal characteristic to the flow…but not quite pure zonal. There will still be very broad, weak troughing in the northern branch of the jet. In such a fast flow, it’s virtually impossible to pick out short waves in that flow, so the mean looks smoother. With the broad troughing, the mean anomaly still points pretty clearly to below average temperatures. Whatever western ridge exists will probably be out well west of N America, so no cross polar flow will be possible in such a regime.
So I have to go back to my tired phrase: “more tolerable.” There is no sign of a western trough which would teleconnect with an eastern ridge, and no sign of a prolonged warming period. Again, though, there is no sign of a cross polar flow with the kind of cold we had on Thursday and will have Sunday-Monday. Unforeseen short waves in week 2 could change that, though there is no way to know that at the time of this posting.