bluewave

Extended EPS has a colder than average first week of November. But the coldest departures are centered to our west. The week two forecast has departures rising back closer to normal. Nov 1-8 Nov 8-15

Yeah, this low is closer to our area this time. So the 40-50 mph gusts will be further west. Windswept heavy downpours tomorrow evening. We’ll see if the NAM marginal severe soundings verify for some localized higher gust potential.

Like we have seen in recent years, October has been one of the warmest on record across our area. So 70° Septembers and 60° Octobers have become more common. Even places like POU came close to a 60° average through October 27th. Time Series Summary for Poughkeepsie Area, NY (ThreadEx) - Month of Oct Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Missing Count 1 2021 59.0 4 2 2017 58.5 0 3 2007 58.0 0 4 1947 57.9 0 5 1971 57.4 0 6 1931 57.3 0 7 1949 56.2 0 8 1932 55.9 2 9 1963 55.8 0 - 1946 55.8 0 10 1989 55.3 0 Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of Oct Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Missing Count 1 2021 65.4 4 2 2017 63.8 0 3 2007 63.5 0 4 1971 63.1 0 5 1990 62.4 0 6 1984 62.2 0 7 1949 61.6 0 8 1963 61.2 0 9 1995 61.0 0 - 1947 61.0 0 10 2019 60.4 0 Time Series Summary for JFK INTERNATIONAL AIRPORT, NY - Month of Oct Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Missing Count 1 2021 63.9 4 2 1971 63.5 0 3 2017 63.2 0 4 2007 63.0 0 5 1984 61.7 0 6 1995 61.6 0 7 1990 61.3 0 8 1949 61.1 0 9 1954 60.1 0 10 2013 60.0 0 Time Series Summary for ISLIP-LI MACARTHUR AP, NY - Month of Oct Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Missing Count 1 2021 62.1 4 2 2017 61.9 0 3 2007 61.1 0 4 1990 60.9 0 5 1971 59.7 0 6 1995 58.5 0 7 1963 58.3 0 8 2019 57.9 0 - 2013 57.9 0 - 2012 57.9 0 9 2016 57.5 0 - 2014 57.5 0 - 1984 57.5 0 10 2020 56.8 0 Time Series Summary for SUSSEX AIRPORT, NJ - Month of Oct Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Missing Count 1 2021 59.4 4 2 2007 58.2 0 3 2017 57.5 0 4 2014 55.9 0 5 2019 54.7 0 6 2012 53.7 3 7 2020 53.1 0 8 2005 52.9 0 9 2013 52.8 0 10 2016 52.7 0

The record warmth in September and October matched our recent delayed fall pattern. This endless summer pattern is reflected in the large September and October temperature increase in the new 1991-2020 climate normals. But the November temperature increase has been smaller. Several Novembers over the last decade were the only cooler departure months of fall. So it’s possible that November may have a smaller warm departure than September and October or a negative departure. Still too early to guess what the actual November temperature departures will be. This is the first fully coupled La Niña November since 2017 and 2016. November 2017 went -0.3 and 2016 finished at +2.3 in the NY Coastal climate division of the NYC five boroughs and Long Island. The monthly temperature increases from 81-10 to 91-20 have been more pronounced during certain months. Newark and Islip are compared below. The +1.0 or warmer months for either station were bolded. ……….EWR…..ISP Dec…+1.5….+1.5 Jan….+1.2…+1.3 Feb….+0.5….+0.5 Mar….+0.4….+0.6 Apr….+0.5…..+0.6 May...+0.6….+0.9 Jun….+0.3….+0.6 Jul…..+1.4…..+1.1 Aug...+0.6….+0.9 Sep….+1.0….+1.3 Oct…..+0.9..+1.4 Nov….+0.2..+0.5 Fall monthly temperature departures in the 5 boroughs of NYC and Long Island September departures 202109 69.2°F 122 3.4°F 202009 66.9°F 99 1.1°F 201909 67.4°F 107 1.6°F 201809 69.6°F 124 3.8°F 201709 68.6°F 118 2.8°F 201609 69.4°F 123 3.6°F 201509 70.8°F 126 5.0°F 201409 67.4°F 107 1.6°F 201309 64.4°F 41 -1.4°F 201209 66.7°F 97 0.9°F 201109 68.7°F 119 2.9°F 201009 68.8°F 121 3.0°F October 202010 57.0°F 104 2.0°F 201910 58.0°F 115 3.0°F 201810 56.5°F 94 1.5°F 201710 62.0°F 126 7.0°F 201610 57.6°F 110 2.6°F 201510 55.5°F 76 0.5°F 201410 57.8°F 112 2.8°F 201310 57.5°F 108 2.5°F 201210 57.9°F 113 2.9°F 201110 56.6°F 97 1.6°F 201010 56.4°F 92 1.4°F November 202011 49.6°F 120 3.7°F 201911 42.3°F 29 -3.6°F 201811 43.6°F 55 -2.3°F 201711 45.6°F 85 -0.3°F 201611 48.2°F 115 2.3°F 201511 50.2°F 126 4.3°F 201411 43.8°F 58 -2.1°F 201311 43.7°F 56 -2.2°F 201211 42.8°F 39 -3.1°F 201111 49.8°F 124 3.9°F 201011 46.2°F 96 0.3°F

With this past storm, the Euro was great with the Saturday and Sunday runs. But it had the 0z Monday run that was too tucked to the SW of MTP. But quickly corrected 12z Monday back to the SE of MTP like the consensus. The wind gusts were also greatly improved. The problem with snowstorms was it had a cold or suppressed bias in recent years. So the heaviest totals were often too far south like in the January 2016 blizzard. It also wouldn’t push the mix line far enough north with more amped systems. That’s why the NAM was almost always spot on with the warm tongue and change to sleet when the pattern supported it. So It wouldn’t be so bad if the Euro has an occasional over amped run in the winter as long as it corrects back closer to storm time. As to the early December blocking forecasts, seems to be related to the current strat warming event. So the vortex remains weaker going forward. We usually do well on snowfall as long as the SPV doesn’t go wild like we saw in 19-20. So hopefully, these weaker SPV forecasts turn out to be correct. It will be interesting to see if this weaker SPV forecast holds going forward. Perhaps the next seasonal update on November 5th will reflect this change.

We’ll see how well the extended EPS does with its weaker SPV and stronger blocking forecast to start December.

The Monday run of the HREF did a good job with the Central Suffolk max.

Updated for 10/25-10/26. https://mesonet.agron.iastate.edu/wx/afos/p.php?pil=PNSOKX&e=202110271605 AWS ...Suffolk County... Ridge 6.82 in 1126 AM 10/27 CWOP

You can see how the shallow warm core more subtropical structure allowed the strongest winds to remain closer to the center than we typically see with the average nor’easter. Isobars not packed tightly away from the immediate center.

Probably the only time that Memorial Day and July 4th weekends had colder than -10 departures followed by none through the end of October. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=32&network=NYCLIMATE&station=NYC004&year=2021&var=avg&gddbase=50&gddceil=86&how=diff&cmap=jet&dpi=100&_fmt=png

Latest NAM gets 50 mph gusts to JFK and LGA with 70 mph near MTP.

Pacific air behind these fronts and storms. So it’s a less warm is the new cool pattern. But even closer to normal at the start of November will feel more fall-like.

This has a shallow warm core so there will be a damaging zone of winds closer to the center where it loops west. There is also no inversion on Eastern Long Island. So all the winds from around 950 to 975 mb should mix down in gusts . LEV PRES HGHT TEMP DEWP RH DD WETB DIR SPD THETA THE-V THE-W THE-E W mb m C C % C C deg knt K K K K g/kg ------------------------------------------------------------------------------- 0 1000 -108 SFC 986 7 14.9 13.0 89 1.9 13.8 18 46 289.2 290.9 287.5 316.1 9.60 2 950 324 11.4 10.6 95 0.7 10.9 24 67 288.7 290.2 286.2 312.5 8.48 3 900 774 9.0 9.0 100 0.0 9.0 32 74 290.7 292.2 286.5 313.5 8.00

The 18z RGEM came west with the cyclonic loop closer to the 18z HRRR.

60-70 mph near MTP and 80 mph near MVY. We will really have to watch where that cyclonic loop occurs for the winds. Those storms that back in from the east are notorious for wind damage near the center.

While these long range SPV forecasts can be very speculative, the latest extended EPS doesn’t have the stronger rebound it did last week. It would be good news if that second dip near the start of December idea has merit. But these forecasts beyond 15 days can often be very uncertain. New run Old run

If you ignore the 0z run, the 12z Euro is similar to 12z yesterday. Still very heavy rains area wide and possible gusts near 70mph on Eastern Long Island. The problem with winter storm tracks was suppression even a day before the storms. So we will be ahead of the game if the suppression issue is fixed. This old bias led to snowfall shifted too far south like during the January 2016 blizzard. 12z today 12z yesterday

High of 77° so far at Newark and only 55° north of the warm front at BDL.

The HREF says make sure that leaves aren’t blocking your storm drains.

The 3km Nam has 70 mph gusts close to Eastern Long Island. But the exact location of where the cyclonic loop occurs will be important. Models may be struggling on where to place the subtropical system with the multiple weaker lows to the west.

New all-time 24 hr rainfall records around Sacramento and wettest October day in San Francisco.

That has been the story since the super El Niño. Warmer winters overall with a strong WAR or SE Ridge in the means. But impressive blocking intervals that always seemed to produce snowstorms for us. So more of a snowy and mild spring in the Rockies type of winter pattern. The record SSTs to the east were like rocket fuel for heavy snowstorms.

The 18z extended HRRR looks more like some of the EPS members.

Looks like the major upgrade also improved the EPS. https://www.ecmwf.int/file/299239/download?token=QzX-fS7a On 12 October, ECMWF implemented the second upgrade of its Integrated Forecasting System (IFS) in 2021. IFS Cycle 47r3 includes numerous changes to the forecast model, observation usage and data assimilation system, with contributions from many teams across the Centre. There are major developments to the representation of moist physics in the model and increased observation usage in cloudy regions in the assimilation. The upgrade improves the large- scale atmospheric circulation and reduces tropical cyclone track errors in both high-resolution (HRES) and ensemble (ENS) forecasts. Several forecast products are modified, such as visibility and wind gusts, and new products are introduced, including clear-air turbulence. Cycle 47r3 brings a major revision to the representation of moist physics in the IFS as well as improvements in the assimilation of observations and increased usage of satellite data in cloudy regions through the extension of the ‘all sky’ approach. An important impact on the forecast is the improvement of the atmospheric circulation, as seen in the increase in skill of extratropical geopotential heights and winds, and with a reduction in wind errors in the tropics of several per cent. The ensemble-mean of error in tropical cyclone position is reduced by 10% between forecast days 2 and 5. There are changes to the character of precipitation, with improvements in the precipitation PDF and in strongly forced convective systems. As well as the many positive signals, a significant change in the physics inevitably leads to some deteriorations, for example in total cloud cover, and these will be addressed in future IFS cycles. There are several new forecast products, such as clear-air turbulence, and improvements to existing products, including visibility and wind gusts. Overall, the package of changes in Cycle 47r3 is an important step in the development of the IFS, improving performance overall, extending our use of existing observations and providing a stronger foundation for further development of the model and data assimilation at current and higher resolutions.

New lowest pressure record for the area off the Pacific Northwest coast.