January 23-February 5, 2005 Pattern Discussion

[donsutherland1]

Last week’s discussion raised a number of issues of what one might expect for the January 16-31, 2005 period.

• In the East, Philadelphia to Boston will likely see some light snow and flurries from a clipper system late Sunday into Monday. Some accumulations are possible. Later, Philadelphia to Boston should see additional accumulating snow in the January 19-21 timeframe. Some areas may see an appreciable snowfall, especially in New England where the potential might exist for at least several inches or more. Washington, DC and Baltimore might also see a small accumulation from this system. However, from Richmond southward, flurries might be the worst of the system.

This period saw several light snowfalls in the East. Richmond received more snow than had been implied. Snowfalls occurred on January 16-17, 18, 19-20 in various cities. The totals for the January 16-21 period were:

Boston: 6.8”
New York City: 1.3”
Philadelphia: 1.0”
Richmond: 1.8”
Washington, DC: 0.8”

• Possible amplification in the closing 5-7 days of the month might heighten the risk of a significant snowfall.

A major snowstorm and even potential blizzard will likely affect parts of the Mid-Atlantic and Northeast, along with the Great Lakes region, in the January 22-23 period. That comes approximately 2 days earlier than the earliest point noted [January 24] in the above range. My thoughts on this storm are contained in a thread devoted specifically to the storm.

• Lowest temperatures during the January 16-22 period may fall below 10° as far south as Philadelphia (the January 14 12z ECMWF takes the 850 mb temperature below –21°C for 1/18 12z in each of these cities). At warmest, look for low teens in New York City and Philadelphia. Boston might see the temperature drop into the lower single digits.

Lowest temperatures during the January 16-22 period:

Boston: 2°, January 19, 21
New York City: 9°, January 18, 19
Philadelphia: 11°, January 18, 19
Washington, DC: 14°, January 18

• Clipper systems will likely add to seasonal snowfall totals in Cleveland, Detroit, Chicago, and Pittsburgh during the January 16-31 period. For the most part, readings there should average below normal and it is possible that Detroit, Chicago, Cleveland, and perhaps Pittsburgh might see the temperature fall below zero one at least one day during the January 21-28 period.

During the January 16-21 period, these cities received the following total snowfall/lowest temperatures:

Chicago: 2.7”; 1°, January 18
Cleveland: 14.3”; 4°, January 18
Detroit: 2.5”; 1°, January 18
Pittsburgh: 4.5”; 1°, January 18

No subzero readings were recorded so far. The aforementioned major snowstorm for the Great Lakes region, Mid-Atlantic, and Northeast will also bring possibly significant snowfall to each of these cities. Again, one can refer to the post specifically devoted to that event for details.

• The January 23-31 period has the potential to bring another strong shot of cold that might send readings into the single digits to Philadelphia. There should be one or two opportunities for accumulating snow in both the Mid-Atlantic and Northeast. I fully expect that Washington, DC through Boston will add to their snow accumulations during this period.

Snow accumulations will increase dramatically in this area from the January 22-23 storm. One or two additional snowfalls could occur before the end of this period. In the wake of the possible weekend blizzard, very cold air could be drilled into the region for a day. During the middle of the coming week (late Wednesday or Thursday), another such air mass could arrive. However, neither air mass seems as cold as the ones that brought readings to the single digits in NYC and Boston.

• Water-logged California should enjoy relatively benign weather for the most part through at least January 25.

Through January 21, the January 16-25 period saw no precipitation in Los Angeles.

• The January 16-22 period will likely see warmer readings return to much of the West. It is possible that this period (perhaps Tuesday or Wednesday) could see the temperature reach 50° in Seattle.

The temperature broke 50° on Monday, January 17. Since then, each day has seen highs above 50°. The warmest reading so far was 62° on January 19.

• While the East is experiencing the return of winter, warmth should overspread the Plains States by the end of the week. Thus Thursday or Friday could see the temperature exceed 40° in Omaha, Kansas City, and Bismarck. The potential exists for the thermometer to climb into the 50s in both Omaha and Kansas City. The following week should remain relatively mild there, though a brief shot of colder air is not out of the question.

Highest temperatures:

Bismarck: 35°, January 19: A bust
Kansas City: 59°, Thursday, January 20
Omaha: 47°, Thursday, January 20

Next week looks to remain generally mild in those cities. Monday and Tuesday could be unseasonably mild with readings in the 40s at Bismarck, and perhaps well into the 50s or near 60° in Omaha and Kansas City.

The January 23-February 5 Ideas:

At present, the NAO is progged to head neutral or somewhat negative for an extended period beginning late in January and continuing into the first few days of February. The same holds for the Arctic Oscillation. Meanwhile, the PNA will likely go negative for a brief period but that trough will likely prove transient with the PNA rebounding near the beginning of February.

At the same time, it should be noted that the Atlantic SSTAs have grown somewhat more favorable for sustaining a negative NAO. So, this lends support to the ensemble ideas.

Per the MJO, it appears that the pattern will become more progressive in the closing days of January. With a more active southern branch of the jet stream and continuing weak El Niño conditions, the rains could return to the West Coast.

• In the East, look for readings next week to become somewhat milder than they were this week (January 16-22). However, a decent cold shot could arrive late in the week (probably around the 1/27-28 period). What is particularly noteworthy is that this cold shot could be arriving at the time the NAO is rising only to fall a short time later. Some notable storms have occurred when the NAO was shifting and also when it averaged between –1 and +1 (Dr. D’Aleo, among others). Right now, there could be some blocking to support the idea of snow in at least the northern Mid-Atlantic and/or New England should any storms push toward the East.

Overall, I believe that the remainder of January should see 1 or 2 additional snowfall opportunities (late 1/25 into 1/26 ahead of the return of unseasonably cold air and perhaps in the 1/29-31 period on a more active Southern Jet.

The first week of February will likely see readings not far from normal but there might be additional storminess as the pattern relaxes to reload for more cold and snow later in the month per analogs.

• The Central Plains will likely remain in a mild and even warm regime. As noted above the 1/24-25 period could be unseasonably mild there before somewhat cooler air returns. The January 30-February 5 period should be somewhat cooler but not extreme.

• As the pattern becomes more progressive, precipitation will likely begin to return to the West Coast probably after January 25. However, I do not believe this wetter period will rival those from December and earlier in January. The wetter regime could last 1-2 weeks per analogs and ensembles.

• The Pacific Northwest should see readings cool down by around January 26. However, shortly after approximately February 3-5, moderation will be likely. Moreover, I do not believe that readings will approach lows achieved earlier this month. For the January 23-31 period, Seattle might see its coldest reading in the 27°-32°. A storm could bring a cold rain during the January 26-27 timeframe.

Analogs and February Snowfall:
Finally, most analogs point to average or above average snowfall across the Mid-Atlantic and Northeast for February. With an increasingly favorable NAO signal, these analogs look reasonable.

Briefly, the analogs show the following:

ENSO:
• Boston: Average snowfall: 13.3”; 10/18 (56%) 10” or more; 6/18 (33%) 15” or more.
• New York City: Average snowfall: 8.8”; 12/18 (67%) 6” or more; 8/18 (44%) 10” or more.
• Washington, DC: Average snowfall: 7.4”; 8/18 (44%) 6” or more

ENSO and PDO:
• Boston: Average snowfall: 14.6”; 6/9 (67%) 10” or more; 3/9 (33%) 15” or more.
• New York City: Average snowfall: 10.6”; 7/9 (78%) 6” or more; 5/9 (56%) 10” or more.
• Washington, DC: Average snowfall: 8.3”; 6/9 (67%) 6” or more

ENSO and QBO:
• Boston: Average snowfall: 16.7”; 3/6 (50%) 10” or more; 2/6 (33%) 15” or more.
• New York City: Average snowfall: 9.8”; 4/6 (67%) 6” or more; 3/6 (50%) 10” or more.
• Washington, DC: Average snowfall: 5.8”; 2/6 (33%) 6” or more

Given the analogs, I believe Boston will see at least 10” of snow in February and possibly more than 15”. I also believe NYC has a good chance at seeing 10” or more snow. Washington, DC should see at least 4” and probably 6” or more. Interestingly enough, no ENSO-QBO analog showed Washington, DC receiving less than 1” of snow in February.

[AnthonyC]

Very interesting analysis. Let's pray that "cold rain" in Seattle turns into "wet snow". The pattern looks to turn zonal for the next two weeks.

[donsutherland1]

AnthonyC,

I'll certainly do so. So far this winter, parts of the Deep South, Ohio Valley, and now Midwest/Northern Mid-Atlantic/Northeast have seen or will see a significant snowfall. Hopefully, before winter is finished, the Pac NW and also SE can see such a snowfall, as well.

[Stephanie]

Well, you certainly NAILED the January 16 - 31 discussion so far.

I'm all tucked in now, waiting for the snow storm/blizzard tomorrow.

[sertorius]

Don:

Thanks again for the great write up-they are always so imformative. I really do think that Kansas City has a good chance of seeing a pretty good snow fall in the next 2 weeks.

1. The PNA looks to remain between 1 and negative 1-very good readings for this area.

2. The gfs, I know it is the gfs but it has done well with trends here this winter, does show the southern stream becomming more active and has had a much stormier pattern beginning next weekend for the past 5 days. The euro and gem has also hinted at storms comming out of the 4 corners areas by next weekend. (I have not seen todays euro as wright weather did not show up)

3. Much of this could be rain of course, but there is hints that our temps. by the end of next week return to normal or just below. It looks to me that we could see our best set up for snow that we have seen all winter in the comming two weeks.

Do I make any sense here-good luck to you on the east coast tomorrow-while fun to watch, that is a very dangerous storm. Thanks again for the information-your accuracy is amazing!!!!

[JenyEliza]

Don,

I enjoyed your discussion, and believe it to be very thorough...however, I didn't see anything in there for the Southeast in the coming period (did I miss it?).

So, was just wondering what you see for us snow/winter starved SE snow weenies?

Don't worry. I can take bad news and disappointment. It's been a couple of years since we've had any decent winter weather.

Thanks!

Jen

[donsutherland1]

JenyEliza,

Through most of the upcoming week, it appears that Atlanta will see generally uneventful weather. With the Southern Jet becoming more active, the possibility of precipitation will have to be watched for as the month nears an end.

At present, there is some but not much support for a strongly negative NAO down the road. If that can be achieved, then prospects for wintry weather could improve markedly. February might bring some opportunities to the Southeast. Hopefully, that will prove to be the case.

[JenyEliza]

JenyEliza,

Through most of the upcoming week, it appears that Atlanta will see generally uneventful weather. With the Southern Jet becoming more active, the possibility of precipitation will have to be watched for as the month nears an end.

At present, there is some but not much support for a strongly negative NAO down the road. If that can be achieved, then prospects for wintry weather could improve markedly. February might bring some opportunities to the Southeast. Hopefully, that will prove to be the case.

Thanks, Don. Pretty much as I expected. I'm afraid at this late date, things are just not looking too good for Atlanta. I haven't given up hope completely, but it seems to me that the likelihood is we're looking at yet another snow-less winter in Falcon-town.

Guess we'll have to learn to appreciate snow from a-far.

Jeny

[donsutherland1]

JenyEliza,

I'll take a closer look at the analogs and see if they have something to lend home to Atlantans in terms of snowfall for February. I might not have the info. until around Monday or so, because I need to find Atlanta's monthly snowfall figures for February.

[JenyEliza]

JenyEliza,

I'll take a closer look at the analogs and see if they have something to lend home to Atlantans in terms of snowfall for February. I might not have the info. until around Monday or so, because I need to find Atlanta's monthly snowfall figures for February.

Not to worry. I have those figures for you right here:

0.0 inches

See...very easy.

Jeny

PS. Don't go to any trouble on this. I've lived in this area since 1968. Generally January is our big snow month. If there's not something in the wings for early February...it's not happening this year. The only time I ever recall snow past February was Superstorm 1993 (where my area got right at a foot of snow).

[JenyEliza]

PS. There's always next year (or so I've been telling myself the last couple of years).