bluewave

The record +IOD may be disrupting or interfering with the MJO. So other factors may play a greater role in our sensible weather. Such as the location of the perma-North Pacific ridge. The NP ridge has been helping to pump the SE Ridge in October. We’ll have to see how this evolves going forward.

It might be a good idea for the NCEP to discontinue these GFS OP runs beyond 240 hrs.

We saw the same cold bias with the snow and cold forecast for this week.

60 degree Octobers are becoming almost as common at LGA as 70 degree Septembers. Even EWR is at 60 this month with NYC not far behind. LGA....+2.1....61.2 EWR....+2.6...60.3 NYC....+2.1...59.9 Time Series Summary for LA GUARDIA AP, NY - Month of Oct Click column heading to sort ascending, click again to sort descending. Year Mean Avg Temperature Missing Count 2019 61.2 6 2018 59.8 0 2017 65.5 0 2016 61.2 0 2015 58.4 0 2014 60.3 0 2013 60.9 0 2012 60.0 0 2011 58.3 0 2010 60.2 0 Time Series Summary for LA GUARDIA AP, NY - Month of Sep Click column heading to sort ascending, click again to sort descending. Year Mean Avg Temperature Missing Count 2019 72.1 0 2018 72.8 0 2017 71.5 0 2016 73.8 0 2015 74.1 0 2014 70.4 0 2013 68.1 0 2012 70.7 0 2011 70.7 0 2010 72.5 0

This says it all.

Yeah, the SST’s warm under the areas where the blocking ridges get stuck.The ridge axis keeps building near the Aleutians. So we get a persistent SE Ridge pattern. The warm SST’s and ridges probably enhance each other in the locations where they line up together.

Sunday is all about where the warm front stalls out. Euro PWATS are 1.75”to 2.00”.The record for the last week of October is 1.8”on the OKX sounding climo. We just don’t know yet where the axis of heaviest rains will set up.

Remarkably stable pattern when you average out the whole year so far. The 2010’s stuck weather patterns give new meaning to persistence forecasting. The big challenge this decade has been timing the shifts from one stuck regime to the next.

This persistent -PNA pattern resulted in a big shift west for the Pacific SST warm blob. It moved from near California to the Aleutians since Labor Day. This reflects a pattern with only transient cool downs before the SE Ridge reloads.

Yeah, it really depends on how the typhoon recurve and ET interacts with the pattern. We saw an opposite response with the Nuri recurve in November 2014. That eventually set new low pressure records in the Bering. NYC will get a mild response this time around. Rather than the -18 departure and 22 degree low in November 2014.

NSIDC put out a tweet about the new record departure.

The jet streak that digs the next big trough out West will be very impressive also. It maxes out around 6 SD in Alaska.

Similar pattern to what we have been experiencing all year. Coldest departures stay out West.Then the cold modifies as it moves east.

The GFS has really been struggling with its cold bias recently. New run Old run

It sure is.

October is on track track for 10 out of 10 above normal temperature departure months for the 2010s. Oct.......EWR...NYC...LGA 2019...+2.5...+1.8...+1.7...so far 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

Oct 2013 .36 and Mar 2012 .96 were the other 2 months for NYC.

We are back to the default wet pattern after the 2nd driest month of the 2010’s. Monthly Total Precipitation for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Mean 3.60 3.92 4.46 3.89 4.82 4.35 4.67 5.11 3.68 3.94 3.48 4.47 49.59 Max 5.23 2015 6.69 2010 10.69 2010 7.85 2014 8.00 2013 10.10 2013 7.45 2018 18.95 2011 9.39 2011 6.09 2011 7.62 2018 6.51 2018 72.81 2011 Min 2.08 2010 1.37 2012 0.96 2012 1.31 2013 1.86 2015 2.20 2010 2.60 2010 1.97 2016 0.95 2019 0.36 2013 1.58 2017 2.21 2017 38.5 2010 2.08 6.69 10.69 2.99 3.01 2.20 2.60 4.14 3.67 4.91 2.15 4.24 49.37 2011 4.93 3.47 6.19 5.35 5.11 3.25 3.03 18.95 9.39 6.09 3.05 4.00 72.81 2012 3.23 1.37 0.96 3.56 5.38 2.97 4.21 2.91 4.39 2.92 1.81 4.80 38.51 2013 2.76 4.25 2.90 1.31 8.00 10.10 2.84 2.85 2.95 0.36 3.15 4.85 46.32 2014 2.79 5.48 3.67 7.85 4.37 4.26 5.59 2.25 1.21 5.77 4.51 6.04 53.79 2015 5.23 2.04 4.72 2.08 1.86 4.79 3.98 2.35 3.28 3.91 2.01 4.72 40.97 2016 4.41 4.40 1.17 1.61 3.75 2.60 7.02 1.97 2.79 4.15 5.41 2.89 42.17 2017 4.83 2.48 5.25 3.84 6.38 4.76 4.19 3.34 2.00 4.18 1.58 2.21 45.04 2018 2.18 5.83 5.17 5.78 3.53 3.11 7.45 8.59 6.19 3.59 7.62 6.51 65.55 2019 3.58 3.14 3.87 4.55 6.82 5.46 5.77 3.70 0.95 3.51 M M 41.35

16-17 was the only season this decade that the November and March departure pattern didn’t match up. Be interesting to see if the relationship holds again this coming season. NYC Season...Nov....Mar 18-19.....-3.3.....-0.9 17-18.....-1.1.....-2.4 16-17.....+2.1....-3.3 15-16.....+5.1....+6.4 14-15.....-2.4.....-4.4 13-14.....-2.4......-4.8 12-13.....-3.8......-2.4  11-12....+4.2.....+8.4 10-11.....+0.2.....-0.2  09-10....+3.4.....+5.7

Yeah, the 2010’s had 6 mild winters and 4 cold ones. But 8 with above normal snow and only 2 below. +T +S 12-13 15-16 16-17 17-18 +T - S 11-12 18-19 -T +S 09-10 10-11 13-14 14-15

Yeah, it was the 2 Fridays in mid-January 1996. The first was the the roof collapse at the Massapequa Waldbaums. The second was the historic Northeast flash flood event. https://www.upi.com/Archives/1996/01/12/Roof-collapses-at-NY-supermarket/2528821422800/ https://www.nws.noaa.gov/oh/hrl/surveys/flood96/FL96chp1.htm#INTRODUCTION ISP Jan 96. 1996-01-12 43 19 31.0 0.5 34 0 1.07 1.0 14 1996-01-13 38 31 34.5 4.1 30 0 0.01 0.0 10 1996-01-14 38 28 33.0 2.6 32 0 0.00 0.0 7 1996-01-15 41 20 30.5 0.2 34 0 0.00 0.0 5 1996-01-16 39 16 27.5 -2.8 37 0 T 0.0 5 1996-01-17 44 35 39.5 9.2 25 0 0.10 0.0 3 1996-01-18 50 34 42.0 11.7 23 0 0.02 0.0 2 1996-01-19 56 28 42.0 11.7 23 0 0.64 T

It all depends on the storm tracks. We can have mild and snowy winter. But not a snowy winter with an unfavorable Pacific like last year. That was the worst January flood-cutter on record for many parts of the Northeast. https://www.weather.gov/bgm/pastFloodJanuary1996

The last season for NYC with every month from November to March with below normal temperatures was 95-96. No surprise that that was our snowiest season on record. The January thaw was also accompanied by one of the worst winter flash flood events in the Northeast. NYC Nov....-4.1 Dec....-5.1 Jan.....-2.1 Feb.....-1.5 Mar.....-3.6

This was the warmest June through September melt season on record.The earlier areas of open water had more time to absorb the extra heat. So now it’s taking longer for the Arctic Ocean to release the extra heat back to the atmosphere. Perhaps warm water influx through the Bering Strait also played a role. But I have no way of measuring that. Recent winds (drift circulation) and warmer ocean waters from heat gained during the early spring melt-out

The main reason we had near record low snowfall last DJF was the strong ridge north of Hawaii and fast Pacific jet. Even some Greenland blocking was no match for such an unfavorable Pacific. While 16-17 and 17-18 were also mild, the NP ridge extended far enough north into Alaska for cold storm tracks needed for snow. The start warm with the strong -NAO in March 2018 really helped us out.