October 2020 General Discussions & Observations Thread

[CIK62]

The last 4 days of October are averaging 51degs.        Making this 48degs., or about -5.0.

Month to date is 59.5[+2.0].       October should end at 58.0[+1.1].

All models have 2.0" to 2.3" for the Zeta remnants.     There are multiple days with lows in 30's into November.     Lowest is the CMC at 27*, EURO at 30*, GFS at 37*.      A warmup should be expected Nov.05-13.

Tropics:    25.1N  91.5W headed for NOLa this evening.      58.7N  22.7W- to North Sea.

56*(80%RH) here at 6am, street wet.       55*(81%RH) at 7am.     54*(86%RH) at 7:30am.     58*(94%RH) by 11am.       56*(95%RH) at Noon.      55*(97%RH) at 1pm.        58*(90%RH) again bet.  4pm-6pm.

[bluewave]

16 hours ago, Allsnow said:

Yep, I honestly think that its a response from all the warm waters off the coast of CA. Typical Niña has cold waters there that makes a -pna more favorable 

Yeah, the ridge locked in near the West Coast keeps warming the SSTs. So we got the smallest north-south SST gradient in the NE Pacific. These are the warmest NE Pacific SSTs we have seen with a La Niña of this strength.

 

[frd]

6 minutes ago, bluewave said:

Yeah, the ridge locked in near the West Coast keeps warming the SSTs. So we got the smallest north-south SST gradient in the NE Pacific. These are the warmest SSTs we have seen with a La Niña if this strength.

 

Interesting 

 

[frd]

 

@bluewave it appears some things that correlated in the past do not show or result in the same outcomes in this new regime with the WPAC warmth and record IOD. Maybe even throw in Greenland ice melt as well.  

The QBO's  sudden shifts  recently is one,  and this post about the October - NAO and active hurricane years is another. 

 

 

[LibertyBell]

13 hours ago, sferic said:

I got 3 inches in Lynbrook in SW nass cnty and 8 inches here in Liberty NY and it was predicted and not a surprise for NYC

3 inches in Lynbrook?  It was more like 1.5 inches also confirmed at JFK

[bluewave]

27 minutes ago, frd said:

Interesting 

 

Notice how the seasonal forecasts from August missed the magnitude of the Ridge parked over Western North America this fall.

UKMET

 

Euro

 

September and October verification

 

 

 

 

 

[wdrag]

Wantage NJ (this part)  0.18 so far today with drizzle in progress. 757A/28

[sferic]

10 minutes ago, LibertyBell said:

3 inches in Lynbrook?  It was more like 1.5 inches also confirmed at JFK

2-3 inches I'll go through my 2011 photo archives; yes those 5 miles or so made a difference from JFK to Lynbrook

[donsutherland1]

Morning thoughts...

At 8:30 AM, an area of rain covered much of extreme southeastern New York, the Long Island Sound and Connecticut. It was heading eastward away from the area. Some showers were still located as far west as northeastern Pennsylvania. Overall, once the light rain and showers exit the region, today will be mostly cloudy and mild. Temperatures will likely reach the upper 50s and lower 60s across the region. Likely high temperatures around the region include:

New York City (Central Park): 60°
Newark: 63°
Philadelphia: 66°

Zeta will bring a general 1"-3" rainfall across the region tomorrow into Friday followed by a shot of sharply colder air. Parts of northern Virginia, Maryland, and Delaware could see 2"-4" of rain.

 

[Eduardo]

1 hour ago, bluewave said:

Notice how the seasonal forecasts from August missed the magnitude of the Ridge parked over Western North America this fall.

UKMET

 

Euro

 

September and October verification

 

 

For comparison, does anybody have a 500mb composite for October 1995?  And maybe a global SST map?   Just curious since that also was an active hurricane season + Niña autumn following a Niño, correct?

[LibertyBell]

2 hours ago, bluewave said:

Notice how the seasonal forecasts from August missed the magnitude of the Ridge parked over Western North America this fall.

UKMET

 

Euro

 

September and October verification

 

 

 

 

 

ridges on the west and east coasts with a sharp trough in between?

 

[bluewave]

28 minutes ago, Eduardo said:

For comparison, does anybody have a 500mb composite for October 1995?  And maybe a global SST map?   Just curious since that also was an active hurricane season + Niña autumn following a Niño, correct?

Much warmer SSTs this October than in 1995. The Western Ridge is also significantly stronger. You can see how much more amplified the 500 MB pattern is this year.

 

 

 

[LibertyBell]

also big difference between the 1994 el nino and the one we had last year.

 

[frd]

14 minutes ago, bluewave said:

Much warmer SSTs this October than in 1995. The Western Ridge is also significantly stronger. You can see how much more amplified the 500 MB pattern is this year.

Makes you wonder if we get the  -NAO effect later in the season from the recent hurricane activity and elevated ace. ( even though not extreme ).

In the back of my mind though is the consequence from all the fires  and the model's seasonal call for a mostly + NAO, although there does seem to be at least the possibility of some cycling at times with the phase of the NAO.      

 

[uncle W]

DJFM monthly nao and ao for winters with at least 30" of snowfall in Central Park...some recent years had 30" of snow with the ao/nao averaging positivefor months...

season........Dec.....Jan.....Feb.....Mar.....lowest/date...

1955-56......0.17...-0.22...-1.12...-0.05.....-1.114....12/17

1957-58......0.12...-0.54...-1.06...-1.96.....-1.651....1/22

1959-60......0.44...-1.29...-1.89...-0.50.....-2.120....1/16

1960-61......0.06....0.41....0.45....0.55.....-0.781....12/9

1963-64.....-1.27...-0.95...-1.43...-1.20.....-2.397....12/13

1966-67......0.72...-0.89....0.19....1.51.....-2.210....1/8

1968-69.....-1.40...-0.83...-1.55...-1.56.....-1.697....12/6

1977-78.....-1.00....0.66...-2.20....0.70.....-2.172....2/13

1993-94......1.56....1.04....0.46....1.26.....-0.854....12/26

1995-96.....-1.67...-0.12...-0.07...-0.24.....-1.846....12/7

2000-01.....-0.58....0.25....0.45...-1.26.....-1.658....12/7

2002-03.....-0.94....0.16....0.62....0.32.....-1.585....12/10

2003-04......0.64...-0.29...-0.14....1.02.....-1.449....1/28

2004-05......1.21....1.51...-0.06...-1.83.....-1.486....3/14

2005-06.....-0.44....1.27...-0.51...-1.28.....-1.360....2/27

2009-10.....-1.93...-1.11...-1.98...-0.88.....-2.250....1/3

2010-11.....-1.85...-0.88....0.70....0.61.....-2.023....12/1

2013-14......0.95....0.29....1.34....0.80.....-0.529....1/12

2014-15......1.86....1.79....1.32....1.45.....-0.909....12/28

2015-16......2.24....0.12....1.58....0.73.....-1.014....1/12

2016-17......0.48....0.48....1.00....0.74.....-1.002....12/6

2017-18......0.00....1.44....1.58...-0.93.....-1.719....3/1

.............................................................................................

1955-56...-0.444 -1.204 -2.029..0.470..-4.564....2/15

1957-58.....0.828 -1.438 -2.228 -2.522..-4.030....3/11

1959-60...-0.042 -2.484 -2.212 -1.625..-4.108....1/28

1960-61...-0.343 -1.506....0.621...0.341..-2.719....1/10

1963-64...-1.188....0.385 -0.575 -0.558..-4.470...12/20

1966-67...-1.401  -0.576...1.180....1.967...-4.147...12/13

1968-69...-0.783 -2.967 -3.114 -1.582...-5.282...2/13

1977-78... -0.240 -0.347 -3.014 0.502...-5.291...2/5

1993-94...-0.104 -0.288 -0.862..1.881....-3.503...2/24

1995-96...-2.127 -1.200....0.163 -1.483...-4.353...12/19

2000-01...-2.354 -0.959 -0.622 -1.687...-4.854...2/25

2002-03...-1.592 -0.472...0.128...0.933...-3.575...1/22

2003-04,,,..0.265 -1.686 -1.528...0.318...-4.387...1/17

2004-05.....1.230...0.346 -1.272 -1.348...-4.337...2/26

2005-06...-2.104 -0.170....0.156 -1.604...-3.569...12/5

2009-10...-3.413 -2.587 -4.266 -0.432...-5.821...12/21

2010-11....-2.631 -1.683....1.575...1.424....-5.172...12/18

2013-14.....1.475 -0.969...0.044...1.206...-2.605...1/27

2014-15.....0.413...1.092...1.403...1.837....-1.462...3/19

2015-16.....1.444 -1.449 -0.024...0.280...-4.898...1/16

2016-17.....1.786...0.942...0.340...1.365....-2.228...2/14

2017-18...-0059 -0.281....0.113 -0.941....-4.426...3/2

[bluewave]

2 hours ago, LibertyBell said:

ridges on the west and east coasts with a sharp trough in between?

 

This was the October version of DJF 17-18.

 

[Eduardo]

31 minutes ago, bluewave said:

This was the October version of DJF 17-18.

 

That's nuts!   You have to wonder what it looks like once it's rolled forward (with shortening wavelengths, etc.).

 

2 hours ago, bluewave said:

Much warmer SSTs this October than in 1995. The Western Ridge is also significantly stronger. You can see how much more amplified the 500 MB pattern is this year.

 

 

 

Thanks for finding these!  I hate tossing '95 out there because it stirs up weenieism.  I didn't realize that '95 had such low heights in the GOA and up top.  NE PAC warm blob was sorta there though.

[Allsnow]

Are coldest day in months is coming on Monday with many areas struggling to get above 40.

[Allsnow]

Tuesday morning temps in the upper 20’s for nyc on the euro 

[MJO812]

6 minutes ago, Allsnow said:

Are coldest day in months is coming on Monday with many areas struggling to get above 40.

With Flakes flying for most

[Allsnow]

2 minutes ago, MJO812 said:

With Flakes flying for most

 

[CIK62]

That GFS just keeps getting warmer for the Nov. 05-13 period.        It seeks to set the Time Clock back a full month or more as 70's are showing up now to go along with the 60's.        The 9 day uncorrected average is 59*, or +10.     Hopefully the correction factor at this range is -8.      GFS T's always S_CK.

The outlook for the month of November is a horror show for North America in general.      Our saving grace here,  is that we are in the area of lowest confidence for the Red/Yellow  +++Codes that are everywhere.

btw:    The SREF is at about 2.1", and has a T of Snow Friday from 8am-Noon.     34* by Saturday AM, hitting freezing appears to have about a 5% chance.

 

[Allsnow]

18 minutes ago, bluewave said:

Looks like our first legit Arctic front of the season. Euro has the 510 thickness line down to our area.

 

 

Yep. Quick shot of artic air then we warm up. Looks like at times we will be very much above normal with the -epo/-pna pattern setting up

[LibertyBell]

1 hour ago, Allsnow said:

Are coldest day in months is coming on Monday with many areas struggling to get above 40.

ouch!  this would be a lock for below freezing lows areawide.....do you have a similar map showing the lows Monday and Tuesday morning?

Typically if the highs are 45 or below, the lows are guaranteed to be below freezing with clear skies.

[LibertyBell]

1 hour ago, Allsnow said:

 

isn't this just flurries and snow showers coming in with the passage of the arctic front?

 

[LibertyBell]

46 minutes ago, Allsnow said:

Yep. Quick shot of artic air then we warm up. Looks like at times we will be very much above normal with the -epo/-pna pattern setting up

regardless this is going to bring the growing season and allergy season to an abrupt end.  YAY

[Allsnow]

24 minutes ago, LibertyBell said:

ouch!  this would be a lock for below freezing lows areawide.....do you have a similar map showing the lows Monday and Tuesday morning?

Typically if the highs are 45 or below, the lows are guaranteed to be below freezing with clear skies.

 

[nycwinter]

18 minutes ago, Allsnow said:

 

those lows are typical of what you get in nyc in mid january...

[donsutherland1]

Hurricane Zeta made landfall along the southeastern Louisiana coast late this afternoon with maximum sustained winds of 110 mph. As of 6:47 pm CDT, New Orleans had picked up 2.90" rain. That broke the daily record of 1.51", which was set in 1980.

Zeta will move rapidly north and then eastward overnight and tomorrow before exiting off the Delmarva Peninsula or perhaps southern New Jersey coastline. As a result, a general 1"-3" rainfall appears likely in much of the region. Parts of northern Virginia, the District of Columbia, Maryland, and Delaware could pick up 2"-4" of rain.

The potential exists that cold air from eastern Canada could be drawn southward to produce at least some snowfall in an area running from northern Pennsylvania, across central New York State, and into central New England. Behind the storm, the coldest air of the season will briefly push into the region.

November will likely commence on a cool note with the first week winding up cooler than normal. A surge of cold air could bring the mercury to freezing even in New York City on Tuesday morning, making for a chilly start to Election Day. A prolonged period of above normal temperatures could develop during the second week of November.

The ENSO Region 1+2 anomaly was -1.1°C and the Region 3.4 anomaly was -1.4°C for the week centered around October 21. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.87°C and the ENSO Region 3.4 anomaly has averaged -1.15°C. La Niña conditions will likely prevail at least into mid-winter.

The SOI was -14.38.

Today, the preliminary Arctic Oscillation (AO) figure was +2.280. That is the highest figure since March 25, 2020 when the AO was +3.174.

On October 27 the MJO was in Phase 6 at an amplitude of 1.623 (RMM). The October 26-adjusted amplitude was 1.941.

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. 9/10 (90%) of the La Niña winters that followed an El Niño winter featured a predominantly positive EPO. A predominant EPO+/AO+ pattern is likely for winter 2020-21. In response, it is likely that the Middle Atlantic and southern New England areas will see a warmer than normal winter with potentially below normal snowfall.

Based on sensitivity analysis applied to the latest guidance, there is an implied 94% probability that New York City will have a warmer than normal October. October will likely finish with a mean temperature near 57.8°.

[Nibor]

4 hours ago, LibertyBell said:

regardless this is going to bring the growing season and allergy season to an abrupt end.  YAY

Amen to that. Sneezing in public these days...