donsutherland1 Posted January 18, 2012 Share Posted January 18, 2012 I'd also be careful about jumping onto a pattern change for the east even if the AO continues to stay negative unless it goes strongly negative like it did last year. February la ninas typically are warmer than normal and a negative AO with a la nina gives you something like this tempwise. Better than we've had but around normal for most of us, if the AO rises to near zero then temps get warm except across the extreme northern plains. Right now I'd lean towards a compromise between the neutral and negative composites even though I think the AO will be negative more than neutral. I agree, Wes. February 1956 (AO average: -2.029) is one example. Unless the AO is severely negative, it will be difficult for it to overwhelm the La Niña pattern in February to the extent that the Eastern third or half of the CONUS is cold. Link to comment Share on other sites More sharing options...
Fantom X Posted January 18, 2012 Share Posted January 18, 2012 I hope so, but am skeptical until there is strong run-to-run continuity on this idea. Both the GFS and ECMWF ensembles have forecast a number of pattern changes that didn't work out. Instead, what one saw were short-lived cooler periods. Recent warming in ENSO Region 1+2 while Region 3.4 has remained relatively stable increases the risk of a February 1999 ENSO situation. February 1999 also had a neutral to somewhat positive AO and neutral PNA (monthly averages). Among the dates listed on the GFS ensembles' 11-day objective analogs centered around 1/29/2012 is 1/25/1999. The ECMWF ensembles also show the MJO finally escaping the low amplitude circle and emerging in Phase 5 at the end of January. Phase 5 is typically mild in the East: So my guess at this point is that the ECMWF ensembles might be hinting at some opportunities for cold shots, but much more evidence needs to become available for me to buy into a cold February scenario. Having said that, I do not believe February 2012 will be a February 1999-style disaster. Something similar to February 1956, but with more expansive warm anomalies seems to be more likely, but that's not yet cast in concrete. Again, this is just my opinion. I could well be wrong (and I hope so). If I remember correctly, February 1999 had a decent cold shot on the 3rd week which was the coldest of the season. It was also followed by a march 1999 snow storm in the middle of the month if I remember correctly as well. Link to comment Share on other sites More sharing options...
donsutherland1 Posted January 18, 2012 Share Posted January 18, 2012 If I remember correctly, February 1999 had a decent cold shot on the 3rd week which was the coldest of the season. It was also followed by a march 1999 snow storm in the middle of the month if I remember correctly as well. That's correct. All in all, February was a warm month. Also, three days after the mid-March snowstorm, temperatures in the New York metro area were in the 60s with some places reaching 70°. Right now, I think there's a reasonable chance that March could wind up cooler than normal in the East. But that's too far away to have much confidence right now. Link to comment Share on other sites More sharing options...
BethesdaWX Posted January 18, 2012 Share Posted January 18, 2012 I agree, Wes. February 1956 (AO average: -2.029) is one example. Unless the AO is severely negative, it will be difficult for it to overwhelm the La Niña pattern in February to the extent that the Eastern third or half of the CONUS is cold. Do you have a record of which La Ninas featured a neutral/+PNA February? Link to comment Share on other sites More sharing options...
Isotherm Posted January 18, 2012 Share Posted January 18, 2012 I'd also be careful about jumping onto a pattern change for the east even if the AO continues to stay negative unless it goes strongly negative like it did last year. February la ninas typically are warmer than normal and a negative AO with a la nina gives you something like this tempwise. Better than we've had but around normal for most of us, if the AO rises to near zero then temps get warm except across the extreme northern plains. Right now I'd lean towards a compromise between the neutral and negative composites even though I think the AO will be negative more than neutral. Wes -- are there maps similar to those for NAO modality? I would think if one coupled a -AO and -NAO, there would be a greater probability of below normal temps on the East Coast. Of course the intensity of that NAO is important as well; a neg AO with a slightly neg NAO (or east based block) may not help too much. Link to comment Share on other sites More sharing options...
usedtobe Posted January 18, 2012 Share Posted January 18, 2012 Wes -- are there maps similar to those for NAO modality? I would think if one coupled a -AO and -NAO, there would be a greater probability of below normal temps on the East Coast. Of course the intensity of that NAO is important as well; a neg AO with a slightly neg NAO (or east based block) may not help too much. I've looked and never found any though I'm sure someone has made them. Link to comment Share on other sites More sharing options...
uncle W Posted January 18, 2012 Share Posted January 18, 2012 I agree, Wes. February 1956 (AO average: -2.029) is one example. Unless the AO is severely negative, it will be difficult for it to overwhelm the La Niña pattern in February to the extent that the Eastern third or half of the CONUS is cold. daily AO index got as low as -4.564 on 2/15...it rose to +4.692 by March 2nd...Stayed + until 3/17...the coldest weather for Feb. came around 2/22 and there was snow in NYC on the 17th...the big snows came after mid March... Link to comment Share on other sites More sharing options...
donsutherland1 Posted January 18, 2012 Share Posted January 18, 2012 Do you have a record of which La Ninas featured a neutral/+PNA February? 1962-63, 1967-68, 1970-71, 1999-00, 2007-08 Link to comment Share on other sites More sharing options...
donsutherland1 Posted January 18, 2012 Share Posted January 18, 2012 In Message #631, I noted that the ECMWF ensembles show the MJO escaping the low amplitude circle and emerging in Phase 5 at the end of January. The January-March MJO chart shows that Phase 5 is typically mild in the East: I ran the data for all February La Niña cases when the MJO was in Phase 5, Amplitude 1-2. The result is strikingly similar to the above chart. Finally, it should be noted that some ensemble members show the AO tanking at the beginning of January. If, in fact, the AO becomes severely negative for a time, then there would be a chance that the first week in February could wind up cold, even if the first day or two starts mild. Right now, it is too soon for me to make the call for the first week in February. Nonetheless, the data I've been looking at still suggests odds favor a mild February overall in much of the East. Link to comment Share on other sites More sharing options...
donsutherland1 Posted January 18, 2012 Share Posted January 18, 2012 Seattle Update... From yesterday (#603): I believe it is reasonable to estimate that Seattle will receive total snowfall of 6"-12" for the 1/17-19/2012 timeframe. Through 12:50 pm PST today, the total snowfall for Seattle since 1/17 was reported at 4.2". However, since then 0.20" additional precipitation had fallen as snow. So far, the big winner in Washington is 4 miles NNW of Chehalis, where 17.0" had fallen as of 12:50 pm PST. Link to comment Share on other sites More sharing options...
NJwinter23 Posted January 19, 2012 Share Posted January 19, 2012 If I remember correctly, February 1999 had a decent cold shot on the 3rd week which was the coldest of the season. It was also followed by a march 1999 snow storm in the middle of the month if I remember correctly as well. There was also a near miss blizzard Feb 25-27th, 1999 that buried Cape Cod under 2 feet Link to comment Share on other sites More sharing options...
donsutherland1 Posted January 19, 2012 Share Posted January 19, 2012 As of 5 pm PST, Seattle had received 6.8" snow. That breaks the daily record for January 18 of 2.9", which was set in 1954. Link to comment Share on other sites More sharing options...
Chris L Posted January 19, 2012 Share Posted January 19, 2012 There was also a near miss blizzard Feb 25-27th, 1999 that buried Cape Cod under 2 feet Indeed. Some of the totals from the Cape ...BARNSTABLE COUNTY... HARWICH 24.0 MARSTONS MILLS 22.0 WEST DENNIS 20.3 OSTERVILLE 20.0 SANDWICH 19.0 YARMOUTH 19.0 Link to comment Share on other sites More sharing options...
HM Posted January 19, 2012 Share Posted January 19, 2012 As of 5 pm PST, Seattle had received 6.8" snow. That breaks the daily record for January 18 of 2.9", which was set in 1954. Interesting. 1953-54 was one of the top analogs this winter (several from this period came up like 52-53, 54-55, 49-50, 56-57). Link to comment Share on other sites More sharing options...
uncle W Posted January 19, 2012 Share Posted January 19, 2012 Interesting. 1953-54 was one of the top analogs this winter (several from this period came up like 52-53, 54-55, 49-50, 56-57). 53-54 had an early November storm similar to our 10/29 storm and got hardly any snow until mid January after a warm December...January 54 was the only good wintry month in NYC... this year could be February... Link to comment Share on other sites More sharing options...
HM Posted January 19, 2012 Share Posted January 19, 2012 53-54 had an early November storm similar to our 10/29 storm and got hardly any snow until mid January after a warm December...January 54 was the only good wintry month in NYC... this year could be February... But it had the right idea about the mid-January pattern shift and then the RNA into the PAC NW. The good news, potentially, for the last few days of January into February is that our stratospheric signals are changing and may allow for more blocking than what occurred in the first half of the winter. Although, there is still a lingering +QBO signal in the lower equatorial stratosphere. Link to comment Share on other sites More sharing options...
donsutherland1 Posted January 19, 2012 Share Posted January 19, 2012 With Seattle picking up more than 6" of snow today, the following is the revised diagram of Seattle's 6" or greater snowstorms (1950-Present). The data for today's storm is preliminary. For the ten 6" or greater snowstorms that occurred in January, 50% occurred during La Niñas and 50% occurred during El Niños. All 10 January snowstorms occurred with a PNA-. Link to comment Share on other sites More sharing options...
donsutherland1 Posted January 19, 2012 Share Posted January 19, 2012 Interesting. 1953-54 was one of the top analogs this winter (several from this period came up like 52-53, 54-55, 49-50, 56-57). I agree, HM. Link to comment Share on other sites More sharing options...
HM Posted January 19, 2012 Share Posted January 19, 2012 I agree, HM. Don, I meant to tell you that your forecasts and thoughts have been excellent. You have been consistently doing a good job and could easily do this for a living and be competitive. Despite the popular belief that no one has been right in the long range, you and a few others have done a tremendous job. Link to comment Share on other sites More sharing options...
usedtobe Posted January 19, 2012 Share Posted January 19, 2012 Don, I meant to tell you that your forecasts and thoughts have been excellent. You have been consistently doing a good job and could easily do this for a living and be competitive. Despite the popular belief that no one has been right in the long range, you and a few others have done a tremendous job. He has done a really good job. Link to comment Share on other sites More sharing options...
donsutherland1 Posted January 19, 2012 Share Posted January 19, 2012 Thank you for the very kind words, HM and Wes. Very best wishes. Link to comment Share on other sites More sharing options...
Isotherm Posted January 19, 2012 Share Posted January 19, 2012 Don, I meant to tell you that your forecasts and thoughts have been excellent. You have been consistently doing a good job and could easily do this for a living and be competitive. Despite the popular belief that no one has been right in the long range, you and a few others have done a tremendous job. I agree, Don's forecasting the past couple of months has been impeccable. Great read on this winter's pattern. Link to comment Share on other sites More sharing options...
buckeye Posted January 19, 2012 Share Posted January 19, 2012 Don, I meant to tell you that your forecasts and thoughts have been excellent. You have been consistently doing a good job and could easily do this for a living and be competitive. Despite the popular belief that no one has been right in the long range, you and a few others have done a tremendous job. Agree. Don and Wes are the two guys I follow wrt the medium range. Great insight no hype and laymans terms... Of course they focus on the east but still can extrapolate. Link to comment Share on other sites More sharing options...
CoastalWx Posted January 19, 2012 Share Posted January 19, 2012 In the 11-15 day, a massive chunk of cold will once again invade western Canada. This in turn will help turn the PNA negative. The 00z GEFS actually have more of an AK ridge into the North POle and a positve looking NAO, while the EC and even Canadian ensembles have a little more in the way of a -NAO..although Canadian is east based. There seems to be a trend of some ridging up near AK, but also..this in turn causes a massive dump of cold into Canada and the NW PAC. As a result, the se ridge tries to pump up a bit. The -NAO looks weak to me right now. It could help out the nrn tier of the US, but if that doesn't materialize, then there is the chance much of the east could be mild. So, it will be interesting going forward to see how the models handle this. Link to comment Share on other sites More sharing options...
DaculaWeather Posted January 19, 2012 Share Posted January 19, 2012 Someone else that has done an excellent job this years is Roger Smith, his October forecast for the winter is eerily accurate. But agreed, thanks for all the insight you guys bring, great place for us old farts to come and learn weather! Link to comment Share on other sites More sharing options...
donsutherland1 Posted January 19, 2012 Share Posted January 19, 2012 Thanks all for the kind words. Link to comment Share on other sites More sharing options...
donsutherland1 Posted January 19, 2012 Share Posted January 19, 2012 This morning, in the wake of Seattle's biggest snowstorm in nearly 11 years, the question for the Pacific Northwest is whether there will be any more snow this winter. Odds strongly favor additional snow in and around the Seattle area. Additional snow fell following 8 of the 9 (89%) previous 6" or greater January storms. Additional snow fell in all four previous January La Niña cases. Sometimes, as was the case following the first two storms in January 1950 and first two storms in January 1969, the additional snowfall was significant. The Pacific Northwest is not the only place where winter weather is present. A little system streaking eastward currently bringing snow to parts of Indiana this morning will bring snow across Ohio then Pennsylvania and then farther east. A 1"-3"/locally 2"-4" could accumulate in parts of Ohio and western Pennsylvania. Snowfall amounts will likely be much lighter as they move into western New England, northern New Jersey, and NYC tonight, but could increase somewhat as Atlantic moisture gets involved farther east in New England. Saturday perhaps into Sunday could see another round of snow in the northern Mid-Atlantic/southern New England region. The potential exists for several inches of snow in some areas. Unfortunately, as has been the case after each cold shot, milder air will quickly follow. The temperature could again rise to much above normal levels by Monday. Link to comment Share on other sites More sharing options...
SnowGoose69 Posted January 19, 2012 Share Posted January 19, 2012 What is the snowiest winter on record for SEA? I'd imagine it can't be much more than about 30 inches or so? Link to comment Share on other sites More sharing options...
Srain Posted January 19, 2012 Share Posted January 19, 2012 Guidance has come into better agreement regarding the 24th-26th time frame and a significant severe weather episode appears likely for the S Plains/Lower Mississippi Valley as a potent storm crosses those regions. HGX is now mentioning a possible repeat of the 1/9/2012 type event that brought 7 tornadoes and flooding to SE TX and points N and E. Link to comment Share on other sites More sharing options...
donsutherland1 Posted January 19, 2012 Share Posted January 19, 2012 What is the snowiest winter on record for SEA? I'd imagine it can't be much more than about 30 inches or so? Seattle has had some very snowy winters. 67.5" fell in 1968-69. 63.6" fell in 1949-50. During the January 5-12, 1880 "Big Snow" event, Seattle received 64". Link to comment Share on other sites More sharing options...
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