Weather models are advertising 2 possible storms for early next week. During this write up I will refer to them as Wave #2 and Wave #3. Wave #1 is a minor event that may bring light snow accumulations to the Jersey Shore, NYC, and Long Island. At this time I think this is a C-2 inch ordeal that may not stick very well to roadways. Timing would be after Midnight late Thursday through 7am Friday morning.
Here is this afternoon's run of the 12z EURO 500mb height anomaly valid 1pm Super Bowl Sunday. I labeled both waves and the northern s/w (short wave) over eastern Canada. Earlier in the week models were keying in on Wave #2. The 500mb trough was closing off further west allowing heights to rise along the EC (east coast) to track a strong surface low up or just off the coast. Recently, models disagree with that notion and are now keying in on Wave #3. Where Wave #2 tracks, how strong the storm gets, and its speed of departing the region DIRECTLY influences how Wave #3 comes together. According to the latest EURO run, the 500mb trough associated with Wave #2 closes off too far S&E which tracks the storm east of the BM (benchmark). It's fair to say Wave #3 de-amplified the trough from Wave #2 which is one reason why H5 closed off too late.
Moving along to 7am Monday, Wave #3 is struggling to come together. You can see Wave #2 is east of the BM but the spacing between it and Wave #3 is too close to allow amplification in the 500mb trough. Further, notice the green "X" over the Great Lakes. This is where this afternoon's run of the EURO closed off H5. The 500mb upper low ends up staying stationed over the Great Lakes instead of digging into the CONUS. The purple "X" is where the 00z EURO run from last night had the 500mb upper low. It dug nicely into the CONUS then tracked east to bring a powerful Miller-B type storm to the area Tuesday of next week.
To get an idea of why the EURO did not dig the H5 upper low nearly as much as its 00z run, let's take a look at the 500mb vorticity map valid 7pm Super Bowl Sunday. We'll stay with the green and purple theme. Green is today's 12z EURO run and purple was the 00z EURO run from last night. In the 00z run, the EURO consolidated the upper energy better and dug it into the central U.S. On the 12z run, the EURO is a bit more scattered with the upper energy and tracks it more east than south. This is the main reason why the 12z run closes H5 off over the Great Lakes while the 00z run closed off in the east-central U.S. Meanwhile, Wave #2 is still hanging around the Southeast U.S. dampening heights. You can see it also is struggling with consolidating upper energy at the base of the trough. The trough remains open and positively tilted.
Taking this information into consideration, here are my thought's:
1. I do not like Wave #2 very much. I think the short wave trough in eastern Canada acts as too much confluence to allow heights to rise along the EC. Sounds familiar, right? Except the Roidzilla two weeks ago did not have another storm right on its heals. Wave #2 and Wave #3 are basically de-amplifying each others flow.
2. One of two things need to happen to get either Wave #2 or Wave #3 to pan out for the area. Either Wave #3 slows down and separates itself from Wave #2 more, or Wave #2 moves out faster than currently modeled to give Wave #3 more space to amplify into the east coast. With an anomalous western ridge I do not see how the upper energy associated with Wave #3 does not dig into the eastern CONUS. I think if Wave #2 was out of the picture this afternoon's run of the EURO would have looked like its 00z run.
3. Unfortunately we run the risk neither wave comes to fruition. If the spacing between both waves remains this close, I fear the upper energy will not come together to promote cyclogenesis. Over the next few days it will be very interesting to see if models focus less on one wave and more on another. Maybe Wave #2 and Wave #3 come together as one wave. I think that's unlikely right now but you never know based off model performance this year.
The upper energy associated with both waves is still located over the eastern and central Pacific Ocean. We have seen drastic changes in modeling once the sampling of these upper energies became clearer. It is important to keep in mind we're working with a ++PNA (again, watch the video) and an EPO / AO going from positive to negative. I personally think these type of signals under an El Nino regime means one of these two storms will come to fruition. It's just a matter of which one. We'll know more by the weekend!
Thanks for reading.
Best,
Francesco Paparatto
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