Weak Disturbance to Bring Light Snow to Parts of East

[donsutherland1]

Tomorrow will see a weak northern branch disturbance pass across parts of the region, bringing some light snow and/or light rain to parts of the area. It will be quite weak and dry with very little qpf.

Right now, southeastern Pennsylvania across northern New Jersey into southern New England, conditions should support mostly light snow. South and east of there, some mixing and even liquid precipitation should occur.

This will not be a memorable event. Snowfall amounts should vary as follows:

Allentown: Around an inch
Atlantic City: An inch or less
Baltimore: 0.5" or less
Harrisburg: 1"-3"
New York City: A coating or less
Philadelphia: 0.5" to 2.5"
Washington, DC: Trace
Wilmington, DE: An inch or less

Wednesday and Thursday will likely see a more important storm slide well to the south. No precipitation is likely from central Virginia northward.

In the longer-range, it still appears that possibly the warmest weather so far this season could move into the Philadelphia to Boston region during the upcoming weekend. The passage of a cold front in the 2/29-3/2 timeframe could crash the early spring party before one becomes too drunk with the forthcoming warmth.

[Skywatch_NC]

In the longer-range, it still appears that possibly the warmest weather so far this season could move into the Philadelphia to Boston region during the upcoming weekend. The passage of a cold front in the 2/29-3/2 timeframe could crash the early spring party before one becomes too drunk with the forthcoming warmth.

LOL...Don!

[Heady Guy]

radar looks decent out in WPA

[Erica]

Nice post, Don, and I pretty much agree with your storm totals. It is pretty moisture starved, but pretty sound dynamically, especially in the short term.

I see that tonight's ECMWF is trying to pull the sub-tropical trough back to the west of Hawaii at Day 10, whereas alst night, it brought it right back east of Hawaii. If there's something to this it could mean that the mean trough will once again be pulled back into the central or western part of the country. Wild card of course, is the NAO. It also had the block along the Arctic Coast of Alaska, and the Polar vortex to the west of Baffin Island.

This might mean that the Arctic airmass crossing the North pole as the ridge amplifies near the Casipan, is sent into the west instead of the eastern part of the country. But even still, I doubt winter is over by any means.

[donsutherland1]

Thanks Erica.

My figures might be a little underdone, particularly for central PA where some 2"-4" locally somewhat higher figures might occur.

I agree with you that the Euro run is quite interesting. Until there is some continuity in its runs with respect to the trough near Hawaii, there will be quite a bit of uncertainty as to where the cold will arrive. It might well head west before it comes east, as you note.

Overall, I fully agree that winter is not yet over especially for the northern Mid-Atlantic and New England regions.

[Erica]

Thanks Erica.

My figures might be a little underdone, particularly for central PA where some 2"-4" locally somewhat higher figures might occur.

I agree with you that the Euro run is quite interesting. Until there is some continuity in its runs with respect to the trough near Hawaii, there will be quite a bit of uncertainty as to where the cold will arrive. It might well head west before it comes east, as you note.

Overall, I fully agree that winter is not yet over especially for the northern Mid-Atlantic and New England regions.

As soon as the trough is pushed back east of Hawaii, with the way the NAO has been lately (strongly negative) the trough and the modified cross polar air will head right back into the east. We haven't been able to lock off the trough in the western part of the country all winter thus far, as some others at the beginning of the season were trying to say, just the same as we did not see the predominance of the southeast ridge (could have been different if solar numbers stayed high though, but they didin't). With the NAO mostly negative and the inability to establish the trough in the west, (or establish any kind of long term positive NAO) it will come right back east, just keep an eye on the critical teleconnection patterns.

Oh, and i forgot to mention that the trough at day 10 is in Scandinavia, which points to the trough coming back into the east.

This probably will turn out to be a war for dominance over the pattern between the various teleconnection points, which in many cases does lead to some interesting things winter wise here in North America.

[donsutherland1]

I like the way the ensemble forecast for the NAO has been so consisent over the past several days. After a projected brief rise toward neutral levels, it is forecast to fall back off to negative levels:

<img src="http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.sprd2.gif">

So, at this point, I'm pretty sure that the cold will return to the East. Timing will probably be somewhat of an issue but the cold should return. With the Southeast Ridge and negative NAO dueling, New England in particular could see some quite interesting weather.

[Erica]

And with the QBO now pretty much west, the chances for getting a sustained PNA ridge, and calming the Polar jet are much better. So winter is not over for anyone in the east, it's just I wish everyone would realize that.

And with the Negative NAO, any system coming through the flow, if weak, could become the new 50/50 low, or a 50/50 low could easily turn the NAO negative given the tendency for one already based on the Atlantic SSTA profiles, trends in the data, and verification. As long as we don't see a strong, or displaced Polar vortex, I don't see any reason why with the way the global indices are, that a major March (Early April?) Nor'easter would not occur. But if I was placing bets with FLguy I would say it would probably happen during a period in which the synoptic pattern is relatively simple, and the Vortex, NAO, and 50/50 low are all favorable.

I would though like to see a bit more of an Increase in equatorial Pacific SSTA, they don't have to reach El Nino criteria, but in order to be more comfortable with the Major March Nor'easter I would like to see Nino 3.4 SSTA run about +0.5 degrees above normal, and the SOI negative over the 10 day period leading up to it.

If everything comes together right, as it has many times before, it could be a storybook March for alot of people.

[donsutherland1]

The 2/23 12Z run of the GFS tried to create that "storybook March" for eastern New England:

<img src="http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_slp_384m.gif">

Sadly, the 2/24 0Z run took it away.

Too bad the Eighth Amendment's prohibition against "cruel and unusual punishments" doesn't apply to the GFS.

[Dave C]

That would have been nice Don! At least I had the early Dec event (18in. total both systems) so no matter what this season wasn't a total loss! This week is the aniversary of the "100hr snowstorm 1969" in New England. I was only 4 yrs. old when it happened but my father told me snow was up to our first floor windows!. After that moved on a coastal moved by March 1st and 2nd bringing another 12 inches.... a total 60 yes 60 inches locally in my town (Middleboro) between the 2 events. Were also moving up on the 1717 event, I'll post a thread with data from various diaries I've aquired showing the results of that historic system.

[donsutherland1]

Dave,

Thanks for your recollections of the February 1969 100-hour storm. I very much look forward to reading your thread on the Great Snow of 1717.

[ColdFront77]

Dave, I too will be looking forward to your thread on the "Great Snow of 1717."    

[donsutherland1]

With respect to yesterday's disturbance, my estimates for snowfall were as follows:

Allentown: Around an inch
Atlantic City: An inch or less
Baltimore: 0.5" or less
Harrisburg: 1"-3"
New York City: A coating or less
Philadelphia: 0.5" to 2.5"
Washington, DC: Trace
Wilmington, DE: An inch or less

Final Totals:

Allentown: 2.2" (Bust: 1.2" above my estimate)
Atlantic City: Trace
Baltimore: None
Harrisburg: 1.0"
New York City: Trace (0.1" on NWS public information statement)
Philadelphia: 0.1" (Bust: 0.4" below range)
Washington, DC: None
Wilmington, DE: 0.1"

All said, this proved not to be an important snowmaker, especially as temperatures remained above freezing for most of the event. Snowfall was generally at the low end of my expectations, with Allentown overperforming with 2.2".

Before day's end, what little snow fell in most areas will be gone in spite of the cold. Now, until at least March, no additional snowfall appears likely in these cities.