bluewave

Some pretty good training of cells last night from just west of JFK up into SW CT. Station Number: NY-QN-33 Station Name: Howard Beach 0.4 NNW Observation Date 10/17/2020 7:00 AM Submitted 10/17/2020 7:18 AM Total Precip Amount 2.48 in. Station Number: NY-NS-27 Station Name: Port Washington 0.8 N Observation Date 10/17/2020 7:14 AM Submitted 10/17/2020 7:18 AM Total Precip Amount 2.39 in. Station Number: CT-FR-25 Station Name: Norwalk 2.9 NNW Observation Date 10/17/2020 7:00 AM Submitted 10/17/2020 7:04 AM Total Precip Amount 2.27 in.

It looks like they may have corrected the longer range cold bias on the parallel GFS v16. But now it seems to have more of a warmer bias instead. So probably fewer long range incorrect snowstorm forecasts. https://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/

Looks like the parallel GFS may have gotten a fix for the cold bias.

The WAR continues to set records. A 5 SD positive 500 height anomaly near Newfoundland for this time of year. The anomalous 592 DM ridge for mid-October will help slow down the front today for soaking rains.

September is right up there also. But this fall so far is less warm than recent years. SEP....EWR...NYC...LGA 2020...+0.9....+0.8....+2.0 2019...+2.6....+2.4....+3.0 2018...+3.2...+2.7....+3.7 2017...+2.7...+2.5....+2.4 2016...+3.6...,+3.8...+4.7 2015...+5.2....+6.5...+5.0 2014..+1.6....+1.7....+1.3 2013...-1.0....-0.1.....-1.0 2012...+1.3...+0.8....+3.4 2011....+3.0..+2.0....+1.6 2010...+3.4....+3.1...+3.4

We are on track for an 11th consecutive warmer than normal October. Oct.......EWR...NYC...LGA 2020..+1.0...+0.9....+1.6...through the 14th 2019..+3.8...+3.0 ...+2.8 2018...+0.8...+0.8...+1.7 2017...+7.2...+7.2...+7.4 2016...+2.3...+1.9....+3.1 2015...+0.6...+1.1....+0.3 2014...+2.7...+2.7....+2.2 2013...+3.0....+3.3...+2.8 2012...+2.2....+1.1....+1.9 2011...+1.5...+0.2.....+0.2 2010...+1.7...+1.2....+2.1

GEFS in full cold bias correction mode as its seeing the stronger WAR pattern. Tough to bet against those very warm SSTs to our east. This is how a -5 forecast for the start of the month turned into a +1 to +3.

The record SST warmth form the Siberian heatwave is slowing down the freeze- up in those regions. https://theconversation.com/arctic-sea-ice-is-being-increasingly-melted-from-below-by-warming-atlantic-water-144106 All this may be feeding into ever more extreme climate change in the Arctic. Throughout summer 2020 the Siberian heatwavecontinually shattered temperature records, including eastern Arctic sea surface temperatures. And while sea ice reflects much of the sun’s rays back into space, open water is dark and absorbs the sun’s heat. So as the sea ice retreated the surface water is warmed, which in turned further warms the atmosphere above, quite apart from the influence of increasing greenhouse gases. There is still much more to learn about the link between the eastwards spread of the influence of Atlantic heat, and the reduction in sea ice it brings, and knock on effects on severe weather at lower latitudes. But it is clear that the Arctic – already warming faster than anywhere else on Earth – could be in the process of transitioning to a “new” state.

It looks like they ran tests without the GFDL microphysics and determined that it was the cause of the cold bias. I am not sure if the new parallel GFS is running one of those suites. Maybe we will get a statement from them once the new parallel becomes operational.

They think that the cold bias is a result of the GFDL microphysics. The whole explanation starts at page #40. I guess changing the microphysics takes time. What is the Cause of This Cold Bias? KEY POINTS: - Suites 1 and 2 (GFDL MP) have a cold bias that increases with lead time - The suites without GFDL microphysics do not show a cold bias increasing w time https://www.weather.gov/media/sti/nggps/NGGPS/EMC MEG Evaluation of GFSv15_Manikin_SIP Meeting_20190514.pdf

It makes more sense to rely on ensemble means beyond day 5 than OP runs. With the rise of social media, the modeling centers need to find a way to limit what type OP data beyond 120 hrs they make freely available. Otherwise, we will just keep getting these incorrect 30 inch snowstorm rumors. https://www.nj.com/weather-guy/2014/02/the_nj_blizzard_that_wasnt_the_anatomy_of_a_social_media_misfire.html

Yeah, extremely amplified pattern coming up. Looks like temperatures rebound back into the 70s Thursday. Then a strong storm that you mentioned with wind and rain. Models have a 590 dm+ ridge around Newfoundland which is close to the record for this time of year near 5 SD. That ridge builds westward over the Northeast day 6-10 for more milder than normal temperatures. Then we’ll have to watch for potential tropical development in the SW Caribbean later in the month.

First 1.00”+ event on the South Shore since the end of September. Wantagh mesonet 1 day: 1.02″

The WAR has been regularly verifying stronger than forecast with the record SSTs since late 2015.

The coolest temperatures should remain to our west as the WAR continues to flex with the warm SSTs to our east.

Stronger Western Atlantic Ridge during the first 10 days of October than the models forecast. So the forecast for a cooler than normal start verified as +1 to +3 across the region. We have seen this model forecast bias frequently in recent years with the record SST warmth to our east. EWR...+1.1 NYC...+1.4 LGA....+2.2 JFK....+1.6 BDR...+2.9 ISP.....+2.0

Close to 80° now in areas to our north with sun. http://wxweb.meteostar.com/meteogram/link.shtml?choice=KBDL

Looks like we will continue to see the coolest temperatures relative to the averages remaining to our west. Ridging is holding in place near the West Coast and just to the east of New England. Matches the areas of the warmest SST departures. Oct 1-7 EPS forecast more of the same Current SST departures

Seems like the Western Atlantic Ridge often finds a way to beat guidance with such warm SSTs off the coast.

I wonder if a specific cause can be found for the record -NAO /-AO from June 2009 through January 2011?Somebody should do a research study on that. You know something unusual was underway when it started with such cool weather for June and July. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Mean Avg Temperature Jun 1 to Jul 31 Missing Count 1 1881-07-31 69.4 0 2 1903-07-31 70.0 0 3 2009-07-31 70.1 0 4 1902-07-31 70.3 0 5 1914-07-31 70.5 0

2-8/9-13 came close for ISP on the LE and it got the 2 consecutive days of 10”+. 2013-02-08 36 25 30.5 -1.2 34 0 2.21 16.7 0 2013-02-09 29 20 24.5 -7.3 40 0 0.74 11.1 25

2-25/26-10 came the closest. NYC got the 2 consecutive LE days over 1.00” but missed the 10” of snow on the 1st day by .6. 2010-02-25 38 27 32.5 -4.7 32 0 2.00 9.4 0 2010-02-26 33 26 29.5 -7.9 35 0 1.17 11.5 14

11-16-89 still stands as our strongest November severe thunderstorm outbreak. https://www.nj.com/weather/2019/11/this-is-what-nj-looked-like-when-7-tornadoes-hit-in-1989-it-sounded-like-incoming-artillery.html