SnoSki14 Posted December 11, 2020 Share Posted December 11, 2020 2 minutes ago, jfklganyc said: Why don’t we worry about our snowstorm this week and cold air that is coming? Considering the same ensembles called for record warmth for the rest of Dec a few days ago, maybe they arent so reliable 15 days out? Just a thought Very true. About a week ago everything looked hopeless with the Nina ridge returning. Can you imagine if the CMC ends up being correct, talk about a giant hammer to all the doom and gloom wall to wall torch winter forecasts. Link to comment Share on other sites More sharing options...
MJO812 Posted December 11, 2020 Share Posted December 11, 2020 6 minutes ago, jfklganyc said: Remember that one one in 99 or 00? Rain to ice to snow and everyone was driving home half tanked in a raging snow storm? 2002 2 Link to comment Share on other sites More sharing options...
MJO812 Posted December 11, 2020 Share Posted December 11, 2020 3 minutes ago, SnoSki14 said: Very true. About a week ago everything looked hopeless with the Nina ridge returning. Can you imagine if the CMC ends up being correct, talk about a giant hammer to all the doom and gloom wall to wall torch winter forecasts. The PV taking a hit most likely has to do with the NAO and AO going negative Link to comment Share on other sites More sharing options...
SI Mailman Posted December 11, 2020 Share Posted December 11, 2020 2002Yep. I was home from Binghamton for winter break and was watching how they got hammered. 6 weeks later I was home for Presidents day weekend and decided to return back to school early to avoid PDII. Link to comment Share on other sites More sharing options...
MJO812 Posted December 11, 2020 Share Posted December 11, 2020 2 minutes ago, SI Mailman said: 9 minutes ago, MJO812 said: 2002 Yep. I was home from Binghamton for winter break and was watching how they got hammered. 6 weeks later I was home for Presidents day weekend and decided to return back to school early to avoid PDII. That Christmas 2002 storm was a nightmare for many people. The forecast was for rain turning to a little snow with temps in the 40s. Christmas Eve started out as rain which lasted through Christmas morning. The rain then quickly changed to heavy wind driven snow as temps plummeted into the upper 20s. At the time I didnt track the weather. I got all my info from TWC. Paul Kocin was on and he stated how the storm was bombing out quicker than modeled. I ended up with 6 inches Link to comment Share on other sites More sharing options...
gravitylover Posted December 11, 2020 Share Posted December 11, 2020 34 minutes ago, jfklganyc said: Remember that one one in 99 or 00? Rain to ice to snow and everyone was driving home half tanked in a raging snow storm? Well they're not supposed to be traveling and visiting family in small settings so that won't happen this time. Right? 1 Link to comment Share on other sites More sharing options...
bluewave Posted December 11, 2020 Author Share Posted December 11, 2020 42 minutes ago, jfklganyc said: Why don’t we worry about our snowstorm this week and cold air that is coming? Considering the same ensembles called for record warmth for the rest of Dec a few days ago, maybe they arent so reliable 15 days out? Just a thought The EPS has had the mid-December storm signal for weeks now. But it also had a moderation in temperatures around the solstice. What it missed was the warm up this weekend. 4 Link to comment Share on other sites More sharing options...
BxEngine Posted December 11, 2020 Share Posted December 11, 2020 1 hour ago, jfklganyc said: Why don’t we worry about our snowstorm this week and cold air that is coming? Considering the same ensembles called for record warmth for the rest of Dec a few days ago, maybe they arent so reliable 15 days out? Just a thought Because this is the december pattern thread and there are threads for specific events earlier than 15 days. 1 Link to comment Share on other sites More sharing options...
the_other_guy Posted December 11, 2020 Share Posted December 11, 2020 51 minutes ago, BxEngine said: Because this is the december pattern thread and there are threads for specific events earlier than 15 days. Yeah the specific event threads have gone wild haha Link to comment Share on other sites More sharing options...
BxEngine Posted December 11, 2020 Share Posted December 11, 2020 29 minutes ago, jfklganyc said: Yeah the specific event threads have gone wild haha Im giving a bit more leeway for now but if the threat remains real some ppl will have to post at accuwx lol 1 1 Link to comment Share on other sites More sharing options...
Allsnow Posted December 11, 2020 Share Posted December 11, 2020 2 hours ago, bluewave said: The EPS has had the mid-December storm signal for weeks now. But it also had a moderation in temperatures around the solstice. What it missed was the warm up this weekend. Eps went towards the gefs for the end of the month today. I think the gefs have a better handle on the mjo. We should be weekly into p7 by the end of the month 1 Link to comment Share on other sites More sharing options...
MJO812 Posted December 11, 2020 Share Posted December 11, 2020 4 minutes ago, Allsnow said: Eps went towards the gefs for the end of the month today. I think the gefs have a better handle on the mjo. We should be weekly into p7 by the end of the month Apparently the cfs now looks good for January. Link to comment Share on other sites More sharing options...
Allsnow Posted December 11, 2020 Share Posted December 11, 2020 2 minutes ago, MJO812 said: Apparently the cfs now looks good for January. The blocking is a result of the wave 1 hit on the vortex. It’s displacing it off the pole. Hopefully we continue to keep it weak to maintain blocking Link to comment Share on other sites More sharing options...
bluewave Posted December 11, 2020 Author Share Posted December 11, 2020 19 minutes ago, Allsnow said: Eps went towards the gefs for the end of the month today. I think the gefs have a better handle on the mjo. We should be weekly into p7 by the end of the month We’ll see if the MJO can weaken by January. 2 Link to comment Share on other sites More sharing options...
Allsnow Posted December 11, 2020 Share Posted December 11, 2020 3 1 Link to comment Share on other sites More sharing options...
SnoSki14 Posted December 11, 2020 Share Posted December 11, 2020 I wonder if the NAO will be as persistent this time around as it has been in the spring months. The first step would be for the coming systems to bring the goods. Nina's with good Decembers typically fair well. Link to comment Share on other sites More sharing options...
bluewave Posted December 11, 2020 Author Share Posted December 11, 2020 19 minutes ago, Allsnow said: You can see how many competing influences there were this month in that 500mb height anomaly map. This may be our first December with a configuration like that. No wonder none of the seasonal model forecasts had a look like that. We were discussing in the other thread back in November how unusual the combination of conflicting SST features were. This could be the 3rd winter in a row that a straight ENSO (El Niño-La Nina) based expectation forecast doesn’t work out. 1 Link to comment Share on other sites More sharing options...
Allsnow Posted December 11, 2020 Share Posted December 11, 2020 Just now, bluewave said: You can see how many competing influences there were this month in that 500mb height anomaly map. This may be our first December with a configuration like that. No wonder none of the seasonal model forecasts had a look like that. We were discussing in the other thread back in November how unusual the combination of conflicting SST features were. This could be the 3rd winter in a row when a straight ENSO based forecast didn’t work out. Yeah, now it seems the long range modeling is defaulting to the Niña pattern but in reality it is something different. We have been kicking the can on the Niña pattern now. Perhaps it comes in February idk Link to comment Share on other sites More sharing options...
bluewave Posted December 11, 2020 Author Share Posted December 11, 2020 8 minutes ago, Allsnow said: Yeah, now it seems the long range modeling is defaulting to the Niña pattern but in reality it is something different. We have been kicking the can on the Niña pattern now. Perhaps it comes in February idk We may just have to take it week by week and month by month. Past expectations based on canonical El Niño or La Niña patterns haven’t been working out since 18-19. Too many competing warm SST blobs for the seasonal models to handle. https://www.climate.gov/news-features/blogs/enso/csi-enso-case-missing-central-pacific-rainfall CSI ENSO: The case of the missing central Pacific rainfall Author: Nat Johnson February 28, 2019 As Emily’s most recent post describes, the tropical Pacific Ocean and atmosphere have finally coupled, allowing NOAA to declare that weak El Niño conditions are present. It’s nice to see the atmosphere and ocean in a cooperative mood, but ENSO forecasters are left with a mystery: why did the expected atmospheric response go missing for so long? In this blog post, we’ll put our detective hats on and look for clues. 2 1 Link to comment Share on other sites More sharing options...
Allsnow Posted December 11, 2020 Share Posted December 11, 2020 21 minutes ago, bluewave said: We may just have to take it week by week and month by month. Past expectations based on canonical El Niño or La Niña patterns haven’t been working out since 18-19. Too many competing warm SST blobs for the seasonal models to handle. https://www.climate.gov/news-features/blogs/enso/csi-enso-case-missing-central-pacific-rainfall CSI ENSO: The case of the missing central Pacific rainfall Author: Nat Johnson February 28, 2019 As Emily’s most recent post describes, the tropical Pacific Ocean and atmosphere have finally coupled, allowing NOAA to declare that weak El Niño conditions are present. It’s nice to see the atmosphere and ocean in a cooperative mood, but ENSO forecasters are left with a mystery: why did the expected atmospheric response go missing for so long? In this blog post, we’ll put our detective hats on and look for clues. Great discussion today with you @bluewave 2 Link to comment Share on other sites More sharing options...
Allsnow Posted December 11, 2020 Share Posted December 11, 2020 2 Link to comment Share on other sites More sharing options...
MJO812 Posted December 11, 2020 Share Posted December 11, 2020 White Christmas on the GFS 2 2 Link to comment Share on other sites More sharing options...
donsutherland1 Posted December 12, 2020 Share Posted December 12, 2020 Tomorrow will be another mild day, but change is coming. Colder air will return to the region after the coming weekend. The recent guidance has suggested a fairly impressive cold shot for late next week. The return of the colder air could coincide with some storminess. There is growing potential for one or two snow events. Afterward, a sustained warmer pattern could develop toward the winter solstice. The closing 10 days of December could wind up generally warmer than normal. The EPS weeklies and subseasonal guidance are in agreement that the last week of December will likely be warmer than normal. Some uncertainty exists, as the AO is likely to remain negative at least into the closing week of December. Historic experience following exceptionally warm November cases suggests that a warmer than normal December remains the base case. Almost 90% of cases with a November mean temperature of 51.5° or above in Central Park (2020 saw the temperature average a record 52.9° in November) went on to record a warmer than normal December and just over three-quarters of such cases saw December register a monthly mean temperature of 40.0° or above. The ENSO Region 1+2 anomaly was -0.5°C and the Region 3.4 anomaly was -1.1°C for the week centered around December 2. 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 -1.35°C. La Niña conditions will likely prevail at least through the winter. The SOI was +5.60. Today, the preliminary Arctic Oscillation (AO) figure was -1.851. On December 10 the MJO was in Phase 5 at an amplitude of 1.373 (RMM). The December 9-adjusted amplitude was 1.080. Based on the latest guidance, no significant stratospheric warming event is likely through the third week of December. Since 1950, there have been five cases where a La Niña developed during June-July-August or afterward following an El Niño winter. 4/5 (80%) of those cases saw a predominant EPO+/AO+ winter pattern. The most recent such case was 2016-17. 10/11 (91%) of the La Niña winters that followed an El Niño winter featured a predominantly positive EPO. A predominant EPO+/AO+ pattern is very likely for winter 2020-21. It is likely that the Middle Atlantic and southern New England areas will see a warmer than normal winter with below normal snowfall. Based on sensitivity analysis applied to the latest guidance, there is an implied 64% probability that New York City will have a warmer than normal December. December will likely finish with a mean temperature near 39.5°. 2 Link to comment Share on other sites More sharing options...
LibertyBell Posted December 12, 2020 Share Posted December 12, 2020 15 hours ago, CPcantmeasuresnow said: Oh God I hope not wait something just occurred to me, NYC still has a chance to attain the 30 inch avg for the 30 year climate period doesn't it and the decade doesn't it? The decade doesn't end until Dec 31st night! Link to comment Share on other sites More sharing options...
LibertyBell Posted December 12, 2020 Share Posted December 12, 2020 11 hours ago, Allsnow said: Yeah, now it seems the long range modeling is defaulting to the Niña pattern but in reality it is something different. We have been kicking the can on the Niña pattern now. Perhaps it comes in February idk 11 hours ago, bluewave said: We may just have to take it week by week and month by month. Past expectations based on canonical El Niño or La Niña patterns haven’t been working out since 18-19. Too many competing warm SST blobs for the seasonal models to handle. https://www.climate.gov/news-features/blogs/enso/csi-enso-case-missing-central-pacific-rainfall CSI ENSO: The case of the missing central Pacific rainfall Author: Nat Johnson February 28, 2019 As Emily’s most recent post describes, the tropical Pacific Ocean and atmosphere have finally coupled, allowing NOAA to declare that weak El Niño conditions are present. It’s nice to see the atmosphere and ocean in a cooperative mood, but ENSO forecasters are left with a mystery: why did the expected atmospheric response go missing for so long? In this blog post, we’ll put our detective hats on and look for clues. maybe what we have been talking about is now coming to fruition, the aberrant behavior of our new climate norms has simply become too complex to boil it down to just ENSO. There are larger factors at play which are going to cause different outcomes because of the changing background state. Link to comment Share on other sites More sharing options...
CPcantmeasuresnow Posted December 12, 2020 Share Posted December 12, 2020 1 hour ago, LibertyBell said: wait something just occurred to me, NYC still has a chance to attain the 30 inch avg for the 30 year climate period doesn't it and the decade doesn't it? The decade doesn't end until Dec 31st night! I've touched on this subject quite a bit the last two years, but now that we're down to the last three weeks I thought it would be a good time to review where NYC, Central Park specifically, stands in the quest for a 30 inch snowfall average when the new 30 year averages are calculated next month. For those not aware how it works the 30 year snowfall averages will be calculated for the period from January 1991 through December 2020. In short this will mean say goodbye to the 1980's from the averages, which hold the record as the least snowiest decade recorded. Assuming NOAA calculates the averages for each month by rounding up or down to the nearest tenth of an inch, the months who have their 30 years completed look as follows: October..........0.1 November.....0.5 December.....4.9 (29 year avg) final number to be determined January.........8.7 February......10.1 March............5.0 April..............0.4 May..................T The 30 year average calculated now would be 29.7 inches. To get December to a 5.2 average, or in this case 5.15 which should round up to 5.2, Central Park will need to record 11.3 inches of snow this December, which is what will be needed to get the 30 year average to 30.0 inches. Currently the December 1991 -2020 period averages 4.773 inches which would round to 4.8 and would make the 30 year average 29.6 inches if no snow falls this December. Here's to hoping that if Wednesday is indeed a surprise heavy snowfall for the city, the Conservancy? doesn't measure 11.2 inches and leave us hanging for the rest of the month. 4 Link to comment Share on other sites More sharing options...
CIK62 Posted December 12, 2020 Share Posted December 12, 2020 The next 8 days are averaging 35degs.(30/40). Making it 30degs., or -6.0. Month to date (missing, site down?) Snow totals summary: Mon. + Wed./Thurs. EURO 2.5" + 14.0", CMC 0 0" + 17.0", GFS 0.5" + 13.0". Non gust winds still 18-25mph. Cautions......Two fast movers, borderline S/R for City, but 2"+ to work with. Euro is running between 15-35 for a week. GFS still goes to the 60's on Christmas. With snow still on the ground?! Come on man. >>>>>>> The 06Z just lost 30 degrees on the Highs for 25th,26th. !!! 51*(85%RH) here at 6am, cloudy,drizzle. [Low was 49* at midnight] 54* by 9am. 1 Link to comment Share on other sites More sharing options...
donsutherland1 Posted December 12, 2020 Share Posted December 12, 2020 Morning thoughts... Today will be mostly cloudy and mild. A few locations could see a shower. Temperatures will likely top out in the lower and middle 50s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 56° Newark: 56° Philadelphia: 59° Next week could see the return of colder air. There is growing support for a significant Middle Atlantic and New England snowstorm for the middle of next week. 1 2 Link to comment Share on other sites More sharing options...
LibertyBell Posted December 12, 2020 Share Posted December 12, 2020 4 hours ago, CPcantmeasuresnow said: I've touched on this subject quite a bit the last two years, but now that we're down to the last three weeks I thought it would be a good time to review where NYC, Central Park specifically, stands in the quest for a 30 inch snowfall average when the new 30 year averages are calculated next month. For those not aware how it works the 30 year snowfall averages will be calculated for the period from January 1991 through December 2020. In short this will mean say goodbye to the 1980's from the averages, which hold the record as the least snowiest decade recorded. Assuming NOAA calculates the averages for each month by rounding up or down to the nearest tenth of an inch, the months who have their 30 years completed look as follows: October..........0.1 November.....0.5 December.....4.9 (29 year avg) final number to be determined January.........8.7 February......10.1 March............5.0 April..............0.4 May..................T The 30 year average calculated now would be 29.7 inches. To get December to a 5.2 average, or in this case 5.15 which should round up to 5.2, Central Park will need to record 11.3 inches of snow this December, which is what will be needed to get the 30 year average to 30.0 inches. Currently the December 1991 -2020 period averages 4.773 inches which would round to 4.8 and would make the 30 year average 29.6 inches if no snow falls this December. Here's to hoping that if Wednesday is indeed a surprise heavy snowfall for the city, the Conservancy? doesn't measure 11.2 inches and leave us hanging for the rest of the month. I see another interesting tidbit in there- February is going to finish with a 10.1 inch average- when was the last time we had a 30 year monthly average in double digits? Link to comment Share on other sites More sharing options...
bluewave Posted December 12, 2020 Author Share Posted December 12, 2020 The AO volatility continues to make headlines. This could be one of the greatest +November to -December reversals on record. Notice how a very +AO in November usually carried over to December. The one exception was 1978. 2020 2.419 3.417 2.641 0.928 -0.027 -0.122 -0.412 -0.381 0.631 -0.072 2.086 2015 1.092 1.043 1.837 1.216 0.763 0.427 -1.108 -0.689 -0.165 -0.250 1.945 1.444 2013 -0.610 -1.007 -3.185 0.322 0.494 0.549 -0.011 0.154 -0.461 0.263 2.029 1.475 2011 -1.683 1.575 1.424 2.275 -0.035 -0.858 -0.472 -1.063 0.665 0.800 1.459 2.221 1994 -0.288 -0.862 1.881 0.225 -0.115 1.606 0.351 0.828 -0.084 0.174 1.779 0.894 1978 -0.347 -3.014 0.502 -0.967 0.059 0.635 -0.604 -0.354 -0.099 0.895 2.470 -0.980 2 1 Link to comment Share on other sites More sharing options...
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