Putting a few things into perspective

[donsutherland1]

Recently, there have been many complaints with the current pattern now in place. To be sure, it has not yet been highlighted by a "Kocin-Uccellini" snowstorm but the pattern is not finished yet. However, in its 18-day lifetime, it has sizzled, especially from the northern Mid-Atlantic into New England.

Select Snowfall Totals (February 17-March 6):

Boston: 22.1"
New York City: 18.7"
Philadelphia: 13.3"
Washington, DC: 5.1"

If one annualizes those rates using a 90-day base for winter, the totals would come to:

Boston: 110.5" (Would rank 1st)
New York City: 93.5" (Would rank 1st)
Philadelphia: 66.5" (Would rank 1st)
Washington, DC: 25.5" (Would rank 27th; not bad, but not special)

As I believe the pattern will not seriously begin to break down until 3/24 +/- a few days (history of extreme blocks, ENSO analogs, NAO climatology), there may yet be an opportunity for a more memorable storm before the pattern changes (at least I hope so). On that, time will tell.

[snow_wizzard]

Don...Do you have any figures on whether there is an increased chance of a major snowstorm in the east as the pattern is in the proces of breaking down. Also, the GFS and ECMWF seem to be hinting that the western blocking ridge will be moving to a position well off the west coast, by early next week. While that brings colder weather to the Pacific NW, is there a chance that it could stay cold, for a time, in the NE as well. This pattern is unfolding in a way I have not seen since I have been viewing the forecast models (some 6 or 7 years now).

[donsutherland1]

Snow_wizzard,

I believe the risk of such a major storm in the East is probably much higher than normal at this time.

• Often when extreme blocks (-5.500 or lower) fade, there is an increased tendency for such a storm to occur. The risk is particularly prominent when there is no La Niña present.

• When the PNA spikes as dramatically as it did in recent days before starting to fall, there is an unusually high correlation between major East Coast precipitation events in March and April.

• The idea that various models have been trying to conjure up such a storm, though not keying in on either the same date or same system, is probably a hint of the pattern's potential. Whether or not that potential is realized remains to be seen.

In my view, the greatest risk of such a storm is probably prior to 3/20. Once the NAO moves positive, given both the season at hand and past experience with storms that resulted during negative NAO regimes, the threat will then be all but gone.

It should be noted that no late-season major snowstorm has occurred in the East when the SOI averaged below -12.6 for March. Such storms have occurred somewhat earlier in February, so I wouldn't be overly concerned about that at this time.

Overall, I believe someone on the East Coast will probably see a 6" or greater storm before the pattern breaks. Whether it is New England (favored by climatology as the calendar advances) or Mid-Atlantic, or both remains to be seen. I don't believe any city from Washington, DC to Boston has seen its last accumulations of snow.

[snow_wizzard]

How realistic of a chance do you think the Pacific NW has of seeing a significant cold spell toward mid month? I have seen enough eye popping runs, showing something a bit out of the ordinary for us, that I have to wonder. On the other hand, I have been known to fall for this "eye candy" a bit too easily at times!

[Jrodd312]

Don whats your thoughts on the upcoming possible snowstorm friday-saturday?

[donsutherland1]

Snow_wizzard,

I believe next weekend could turn colder in the Seattle area. I'm not sure about any extraordinary cold this month but there's plenty of time for things to change.

[donsutherland1]

John,

I believe there is reasonable possibility for a storm to bring accumulating snow during that timeframe. Questions as to track and intensity remain to be answered. Also, the Monday-Tuesday system that will bomb out on the way to eastern Canada could have an impact on how things evolve. Overall, this remains a very challenging environment for the computer guidance and there may yet be changes in such guidance, so I wouldn't place a great deal of confidence in any single solution at this point in time. When things are closer to the event, a better idea should be available.