The jet stream has been pretty zonal with a few dips and some clippers hitting the northeast. Do you forsee any change to where the US has a big dip in the jet w/southeast storm potentials?
Posted January 6, 2008
MIKE MOSS SAYS: Josh, That kind of pattern isn't favored as frequently during moderate to strong La Nina winters in a historical sense, but there can certainly be exceptions to that tendency as we saw with the January 2000 snowstorm. We did get a deep eastern trough last week (when we can't top 35 degrees despite cloud-free skies, it's a cold airmass indeed) but as you know the only notable disturbance to cross the area while the cold air was in place only managed to produce a few flurries over the northern third or so of our area.
Until we move within about 3-5 days of the next potential deep eastern trough that is well-positioned for both providing cold air and generating surface lows to our south and southeast, there isn't any very reliable way to say that they will or will not occur at any specific time. Looking well ahead on today's GFS (global forecast system) computer model, there are indications of just such a pattern around the 13th and 15th of this month. However, it is not unusual to see model results that far into the future change significantly as we draw closer to the dates in question, and some other models (ECMWF, for example) suggest more digging of the jet toward the southwestern U.S. in that same time frame, which would not be as favorable for cold weather and precipitation over central and eastern NC. We'll have to check the trends over the next week or so to see if the current projections hold, and which, if either, current model solution for those time periods turns out to be correct.