Rjay Posted January 17, 2021 Share Posted January 17, 2021 Gfs now shows the same trailing s/w that the Euro showed last night 1 Link to comment Share on other sites More sharing options...
Rjay Posted January 17, 2021 Share Posted January 17, 2021 3 Link to comment Share on other sites More sharing options...
TriPol Posted January 17, 2021 Share Posted January 17, 2021 11 minutes ago, donsutherland1 said: Below is a scatter diagram for New York City's daily snowfall of 4" or more during the January 21-31, 1950-2020 period based on the AO/PNA: How is the PNA today? 1 Link to comment Share on other sites More sharing options...
eduggs Posted January 17, 2021 Share Posted January 17, 2021 17 minutes ago, donsutherland1 said: Below is a scatter diagram for New York City's daily snowfall of 4" or more during the January 21-31, 1950-2020 period based on the AO/PNA: Nice plot. Is it also possible to plot the base rate - the AO/PNA scatter diagram for all days? Link to comment Share on other sites More sharing options...
donsutherland1 Posted January 17, 2021 Share Posted January 17, 2021 12 minutes ago, TriPol said: How is the PNA today? Still positive (+0.523). However, it is forecast to fall sharply. There is strong consensus on the guidance for the PNA to go negative over the next 5-7 days and then strongly negative afterward. 1 Link to comment Share on other sites More sharing options...
donsutherland1 Posted January 17, 2021 Share Posted January 17, 2021 5 minutes ago, eduggs said: Nice plot. Is it also possible to plot the base rate - the AO/PNA scatter diagram for all days? All days in January or all cases? The latter would lead to a noisier outcome on account of differing wave lengths. Link to comment Share on other sites More sharing options...
eduggs Posted January 17, 2021 Share Posted January 17, 2021 2 minutes ago, donsutherland1 said: All days in January or all cases? The latter would lead to a noisier outcome on account of differing wave lengths. All days during the January 21-31, 1950-2020 period. Link to comment Share on other sites More sharing options...
NEG NAO Posted January 17, 2021 Share Posted January 17, 2021 12Z GEM basically a miss to the south for most of the metro - GFSv16 hasn't started running at 12Z for whatever reason as of 11:59 am 1 Link to comment Share on other sites More sharing options...
Brian5671 Posted January 17, 2021 Share Posted January 17, 2021 Seems more like a March pattern not much in the way of arctic air which will make track all the more important. Link to comment Share on other sites More sharing options...
donsutherland1 Posted January 17, 2021 Share Posted January 17, 2021 21 minutes ago, eduggs said: All days during the January 21-31, 1950-2020 period. Here you go: 2 Link to comment Share on other sites More sharing options...
MJO812 Posted January 17, 2021 Share Posted January 17, 2021 51 minutes ago, NEG NAO said: 12Z GFS -redevelops off coast but too warm Gefs is further south compared to 6z gefs and 12z op. Link to comment Share on other sites More sharing options...
EastonSN+ Posted January 17, 2021 Share Posted January 17, 2021 I will never learn. Weeklies and ensembles past day 10 are useless. GEPS now looks terrible at day 15. Not sure what EPS looks like. 2 Link to comment Share on other sites More sharing options...
Brian5671 Posted January 17, 2021 Share Posted January 17, 2021 4 minutes ago, EastonSN+ said: I will never learn. Weeklies and ensembles past day 10 are useless. GEPS now looks terrible at day 15. Not sure what EPS looks like. Starting to look like other years where the pattern doesn’t materialize. Always seems to be around mid January 1 Link to comment Share on other sites More sharing options...
snowman19 Posted January 17, 2021 Share Posted January 17, 2021 11 minutes ago, EastonSN+ said: I will never learn. Weeklies and ensembles past day 10 are useless. GEPS now looks terrible at day 15. Not sure what EPS looks like. GEPS has been getting progressively more Niña looking going into February since the Thursday night run. I posted about it this morning, BAMWX pointed it out that the EPS and GEFS are backing off the very cold runs for the long range they had and are both markedly warming up each cycle for the last several runs.... Link to comment Share on other sites More sharing options...
ALEXA Posted January 17, 2021 Share Posted January 17, 2021 follow the soi. it's been positive for weeks. only went it goes negative the cold will come. 1 Link to comment Share on other sites More sharing options...
CIK62 Posted January 17, 2021 Share Posted January 17, 2021 HELP ME RHONDA YEAH!!!..................Get Me Out of this Winter................ Polar Vortex Bust keeps getting worse. We do not break 20 at mid-winter with a loose PV???!!! The last 7 days of January are now averaging 33degs.(28/38), a full 12 degrees more than just 3 runs back. 1 Link to comment Share on other sites More sharing options...
White Gorilla Posted January 17, 2021 Share Posted January 17, 2021 42 minutes ago, JoshSnow said: The real cold comes in mid to late February this year. Probably in April and May like last year. Mother's Day flurries, anyone? 2 2 Link to comment Share on other sites More sharing options...
wdrag Posted January 17, 2021 Share Posted January 17, 2021 GFSV16 has started for the 12z/17 cycle. at 24 hours as of this post. Link to comment Share on other sites More sharing options...
EastonSN+ Posted January 17, 2021 Share Posted January 17, 2021 53 minutes ago, Brian5671 said: Starting to look like other years where the pattern doesn’t materialize. Always seems to be around mid January What drives me crazy is a lot of Mets predicted a bad year for snowfall due to no blocking and poor Pacific. We had great blocking and it still didn't matter. I can't remember ever having great blocking in a Nina and not getting a decent winter. I have only seen super Nino's with blocking fail like late 90s. Link to comment Share on other sites More sharing options...
Brian5671 Posted January 17, 2021 Share Posted January 17, 2021 5 minutes ago, EastonSN+ said: What drives me crazy is a lot of Mets predicted a bad year for snowfall due to no blocking and poor Pacific. We had great blocking and it still didn't matter. I can't remember ever having great blocking in a Nina and not getting a decent winter. I have only seen super Nino's with blocking fail like late 90s. The +EPO is killing us this go around Link to comment Share on other sites More sharing options...
EastonSN+ Posted January 17, 2021 Share Posted January 17, 2021 Just now, Brian5671 said: The +EPO is killing us this go around Yeah but we have had plenty of +epo winter's with blocking and we scored decently. I firmly believe if we had more storm chances we would have had some snow this winter. Our temps were fine with the right track. 1 Link to comment Share on other sites More sharing options...
EastonSN+ Posted January 17, 2021 Share Posted January 17, 2021 Perhaps this winter is an anomaly. I do think someone said this winter was close to 1922 1923? Link to comment Share on other sites More sharing options...
NEG NAO Posted January 17, 2021 Share Posted January 17, 2021 12Z Euro looks like Canadian - a miss south mostly Link to comment Share on other sites More sharing options...
eduggs Posted January 17, 2021 Share Posted January 17, 2021 1 hour ago, donsutherland1 said: Here you go: Thanks. That's helpful to visualize the relative likelihoods and typical ranges of each state during this upcoming time of year. It's hard to tell, but it looks like AO-/PNA+ is most common. Link to comment Share on other sites More sharing options...
eduggs Posted January 17, 2021 Share Posted January 17, 2021 19 minutes ago, EastonSN+ said: What drives me crazy is a lot of Mets predicted a bad year for snowfall due to no blocking and poor Pacific. We had great blocking and it still didn't matter. I can't remember ever having great blocking in a Nina and not getting a decent winter. I have only seen super Nino's with blocking fail like late 90s. It's a crap shoot. Perfectly timed shortwaves can produce major storms in any "pattern". And a great "pattern" with a slight wrinkle in the setup can produce zilch. The large scale synoptic features certainly increase or decrease the likelihood of a good winter, but there is also a lot of luck (randomness) involved. 4 1 Link to comment Share on other sites More sharing options...
Brian5671 Posted January 17, 2021 Share Posted January 17, 2021 15 minutes ago, EastonSN+ said: Yeah but we have had plenty of +epo winter's with blocking and we scored decently. I firmly believe if we had more storm chances we would have had some snow this winter. Our temps were fine with the right track. Winters are warmer now. Seems like more of a DC type climate around here last 5-6 yrs 5 1 Link to comment Share on other sites More sharing options...
MJO812 Posted January 17, 2021 Share Posted January 17, 2021 16 minutes ago, NEG NAO said: 12Z Euro looks like Canadian - a miss south mostly Holding back energy Would be a different solution if it ejected it 1 Link to comment Share on other sites More sharing options...
donsutherland1 Posted January 17, 2021 Share Posted January 17, 2021 35 minutes ago, eduggs said: Thanks. That's helpful to visualize the relative likelihoods and typical ranges of each state during this upcoming time of year. It's hard to tell, but it looks like AO-/PNA+ is most common. For another look, below is the percentage of days for select AO/PNA states and the percentage of days with 4" or greater snowfalls for New York City during the January 20-31, 1950-2020 period for each of those states: AO-/PNA+: 39% days, 67% of daily 4" or greater snowfalls AO-/PNA-: 19% days, 5% of daily 4" or greater snowfalls AO+/PNA+: 20% days, 24% of daily 4" or greater snowfalls AO+/PNA-: 22% days, 5% of daily 4" or greater snowfalls Link to comment Share on other sites More sharing options...
Rjay Posted January 17, 2021 Share Posted January 17, 2021 1 hour ago, NEG NAO said: 12Z Euro looks like Canadian - a miss south mostly Here's the 24 hour difference in runs out west as our storm organizes. The new run had less phasing out west and buried the s/w. A piece broke off and ended up to our south under the block. 1 2 Link to comment Share on other sites More sharing options...
donsutherland1 Posted January 17, 2021 Share Posted January 17, 2021 Today was partly sunny and breezy. Temperatures generally topped out in the lower and middle 40s across the region. Tomorrow will be a similar day. During the second half of January, there will be some potential for snow events in the Middle Atlantic and southern New England regions, even as the forecast AO-/PNA- pattern is typically not a very snowy one. There continues to be ensemble support for a possible light snow event in the region during the January 21-23 timeframe during the passage of a strong cold front. Another timeframe highlighted by the ensembles is January 25-28. The latter period may have greater potential. However, neither period is likely to produce a significant snowfall (6" or above) for the Washington, DC to Boston corridor. AO-/PNA- patterns are typically not snowy. The frequency of measurable snowfall is just over 90% of climatology in Boston and Philadelphia and around 80% of climatology in New York City for the January 21-31, 1950-2020 period. The frequency of 2" or more daily snowfall was just above 90% of climatology for Philadelphia, but fell sharply to 50% of climatology in New York City and 65% of climatology in Boston. For daily snowfall amounts in excess of 2", the frequency fell sharply for Philadelphia. As a result, such patterns typically have produced significant snowstorms (6" or above snowfall) in the northern Middle Atlantic and southern New England regions during late January. The biggest snowfalls during an AO-/PNA- pattern during the January 20-31, 1950-2020 period were as follows: Boston: 7.3", January 21, 2011; New York City: 4.2", January 21, 2011; and, Philadelphia: 3.0", January 20, 2000. Afterward, the evolution of the AO will determine whether potential for measurable snow events will continue into February. The ENSO Region 1+2 anomaly was -0.8°C and the Region 3.4 anomaly was -1.1°C for the week centered around January 6. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.77°C and the ENSO Region 3.4 anomaly has averaged -1.07°C. La Niña conditions will likely prevail at least through the winter. The SOI was +20.69 today. Today, the preliminary Arctic Oscillation (AO) figure was -1.579. On January 16 the MJO was in Phase 4 at an amplitude of 1.143 (RMM). The January 15-adjusted amplitude was 1.148. Following a significant stratospheric warming event, the stratosphere is now cooling. The cooling will likely accelerate during the second half of January. As is typical for vortex-splitting events, the major piece of the polar vortex migrated to Eurasia. The end result has been an absence of severe cold in much of North America. The significant December 16-17 snowstorm during what has been a blocky December suggests that seasonal snowfall prospects have increased especially from north of Philadelphia into southern New England. At New York City, there is a high probability based on historic cases that an additional 20" or more snow will accumulate after December. Were blocking to disappear, snowfall prospects would diminish. Based on sensitivity analysis applied to the latest guidance, there is an implied 83% probability that New York City will have a warmer than normal January. January will likely finish with a mean temperature near 35.2°. 1 Link to comment Share on other sites More sharing options...
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