bluewave

Too much SE flow for places like Newark to get closer to 100. Probably a 98 to 99 with more SW flow since the Mount Holly NWS office got so warm.

I have gained more benefit from observing where the model analysis and forecasts have been off and extrapolating how that could impact winter forecast going forward. But that isn’t something that a model without AI will be able to show you. I have been able to identify some seasonal drivers based on the fall patterns. But this has mostly been a function of the general warmer winter pattern composites since the 15-16 super El Niño. The really good stuff like the January into February 2016 near record KB block and blizzard pattern really didn’t become evident until we got past the +13 December. So you couldn’t put together a winter forecast that fall that saying you expected +13 December followed by the the biggest NYC snowstorm on record and first below 0 reading since 1994. Likewise for going 80° in February 2018 and then record March snows to follow. Same goes for the +PNA in the 20-21 winter despite the strong- PDO reading. And the even more striking Jan 22 +PNA against the record low -PDO pattern. This list can go on and on even back to the 09-10 winter with the extreme shifts from winter to winter some years and stuck warm patterns since 15-16. And laughable abrupt shifts within the same winter into early spring.

I am not a big fan of using any of these ENSO or seasonal forecasts. I believe the last correct seasonal forecast was 13-14 from the JMA? That record NE PAC ridge must have been easy to spot for some reason in the model forecast from the early fall. These long range model forecasts beyond 15 days are to some extent just versions of the 384hr gfs snowstorms in winter. Maybe AI will finally allow the models to do a correct seasonal forecast.

The effects will be enhanced closer to the farming areas and reduced somewhat in the more urban spots away from agriculture. My main opening post mentioned the declining highs and rising lows right at the farms. But this general pattern exists to some extent throughout the region. New research finds that irrigated farms within Wisconsin’s vegetable-growing Central Sands region significantly cool the local climate compared to nearby rain-fed farms or forests. Irrigation dropped maximum temperatures by one to three degrees Fahrenheit on average while increasing minimum temperatures up to four degrees compared to unirrigated farms or forests. In all, irrigated farms experienced a three- to seven-degree smaller range in daily temperatures compared to other land uses. These effects persisted throughout the year.

What isn’t to buy? Omaha has had unchanged summer high temperatures since the rapid expansion of corn production from 1961-1990 to 1991-2020 at 85.3. Remember that is only one point the map. Numerous higher order sites in the NCDC network have actually seen a small drop in temperature. Any increase in average temperatures is a result of rising minimums which is due to the corn producing higher dew points. Monthly Mean Max Temperature for Omaha Area, NE (ThreadEx) Click column heading to sort ascending, click again to sort descending. Year Jun Jul Aug Season Mean 83.7 87.3 85.0 85.3 2020 89.2 89.6 88.6 89.1 2019 83.5 87.3 83.7 84.8 2018 87.6 87.5 86.0 87.0 2017 88.2 90.5 83.1 87.3 2016 90.6 87.1 85.9 87.9 2015 83.4 86.9 82.9 84.4 2014 83.4 84.3 83.8 83.8 2013 81.6 86.9 87.2 85.2 2012 87.1 96.9 88.2 90.7 2011 82.5 90.1 84.9 85.8 2010 84.4 87.3 89.2 87.0 2009 81.6 81.7 81.9 81.7 2008 82.3 87.2 87.6 85.7 2007 83.7 89.6 87.7 87.0 2006 86.9 91.5 83.9 87.4 2005 85.9 90.9 85.5 87.4 2004 78.8 82.1 80.3 80.4 2003 79.7 89.5 89.7 86.3 2002 88.4 91.5 85.2 88.4 2001 82.2 88.5 86.8 85.8 2000 82.0 84.0 87.0 84.3 1999 80.2 90.4 82.8 84.5 1998 79.4 85.5 84.9 83.3 1997 85.7 87.3 83.2 85.4 1996 83.7 82.9 82.2 82.9 1995 82.4 91.9 90.2 88.2 1994 84.0 84.2 84.0 84.1 1993 78.5 81.5 82.7 80.9 1992 79.3 78.5 77.9 78.6 1991 83.7 85.4 84.2 84.4 Monthly Mean Max Temperature for Omaha Area, NE (ThreadEx) Click column heading to sort ascending, click again to sort descending. Year Jun Jul Aug Season Mean 83.4 87.6 84.9 85.3 1990 83.3 83.7 84.9 84.0 1989 80.2 87.0 84.5 83.9 1988 88.2 86.3 88.8 87.8 1987 85.2 88.9 79.6 84.6 1986 84.4 87.1 78.7 83.4 1985 79.1 85.8 80.0 81.6 1984 81.7 86.8 88.2 85.6 1983 79.4 89.8 92.0 87.1 1982 76.2 86.5 80.3 81.0 1981 84.9 85.7 80.5 83.7 1980 82.9 89.7 86.2 86.3 1979 81.9 82.8 83.6 82.8 1978 83.2 84.6 84.5 84.1 1977 83.6 89.7 80.4 84.6 1976 86.4 90.9 90.1 89.1 1975 83.9 92.1 92.0 89.3 1974 83.7 97.1 82.0 87.6 1973 86.2 85.6 89.2 87.0 1972 85.2 84.0 83.8 84.3 1971 89.7 85.6 86.7 87.3 1970 86.0 89.3 87.8 87.7 1969 79.0 87.5 86.2 84.2 1968 86.0 87.3 85.0 86.1 1967 80.8 86.2 84.0 83.7 1966 83.2 88.9 82.3 84.8 1965 81.7 85.3 86.1 84.4 1964 83.0 91.0 82.0 85.3 1963 86.8 88.8 85.0 86.9 1962 82.3 85.6 85.9 84.6 1961 82.7 87.5 85.5 85.2

MEI still ENSO neutral at +0.4 on the latest update. https://psl.noaa.gov/enso/mei/

We can use the 90°day data from 1970 to 1983 when the Central Park thermometer wasn’t under the trees.The comparison is to the much warmer present era from 2010-2023 with tree growth impeding accurate observations. There is no reason other than tree growth for NYC to have the number of 90° days reamain at 19 with how much the climate has warmed since then. Both LGA and EWR show a significant increase in 90° days as the climate has warmed. The Hudson Valley shows the same trend as LGA and EWR. POU has nearly doubled its number of 90° days. Again, there is no reason for POU to have more 90° days now than NYC. So using a proportional 90° day increase similar to EWR, they would most likely have an around 30 days a year reaching 90° instead of 19 if the site was properly maintained. This would mean the Great Lawn probably sees that # of 90° days since it isn’t in the shade. But an increase similar to LGA and POU would place that number even higher. Monthly Number of Days Max Temperature >= 90 for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Apr May Jun Jul Aug Sep Oct Season Mean 0 1 2 8 6 2 0 19 1983 0 0 6 14 9 7 0 36 1982 0 0 0 11 0 0 0 11 1981 0 0 2 10 4 0 0 16 1980 0 2 1 11 15 3 0 32 1979 0 2 0 7 8 1 0 18 1978 0 1 2 3 5 0 0 11 1977 1 2 0 11 7 2 0 23 1976 3 0 6 2 4 0 0 15 1975 0 1 1 2 4 0 0 8 1974 0 1 1 10 5 0 0 17 1973 0 0 4 4 6 4 0 18 1972 0 0 0 11 3 1 0 15 1971 0 0 5 6 5 2 0 18 1970 0 2 1 4 8 7 0 22 Monthly Number of Days Max Temperature >= 90 for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Apr May Jun Jul Aug Sep Oct Season Mean 0 1 3 9 5 2 0 19 2023 2 0 1 5 0 2 M 10 2022 0 2 1 10 11 1 0 25 2021 0 0 8 4 5 0 0 17 2020 0 0 2 14 4 0 0 20 2019 0 0 1 10 3 0 1 15 2018 0 2 3 6 7 3 0 21 2017 0 3 3 5 1 1 0 13 2016 0 2 0 10 7 3 0 22 2015 0 0 1 5 8 6 0 20 2014 0 0 0 3 3 2 0 8 2013 0 2 3 10 1 1 0 17 2012 0 0 5 10 3 1 0 19 2011 0 0 3 14 3 0 0 20 2010 1 1 4 16 12 3 0 37 Monthly Number of Days Max Temperature >= 90 for LAGUARDIA AIRPORT, NY Click column heading to sort ascending, click again to sort descending. Year Apr May Jun Jul Aug Sep Oct Season Mean 0 1 2 6 4 2 0 14 1983 0 0 5 11 8 7 0 31 1982 0 0 0 6 0 0 0 6 1981 0 0 2 11 2 0 0 15 1980 0 0 3 8 9 2 0 22 1979 0 2 0 7 7 0 0 16 1978 0 0 0 3 1 0 0 4 1977 0 1 0 9 3 1 0 14 1976 1 0 5 1 3 0 0 10 1975 0 1 1 2 3 0 0 7 1974 0 1 1 9 2 0 0 13 1973 0 0 3 3 7 4 0 17 1972 0 0 0 3 0 1 0 4 1971 0 0 3 3 2 1 0 9 1970 0 2 1 5 9 5 0 22 Monthly Number of Days Max Temperature >= 90 for LAGUARDIA AIRPORT, NY Click column heading to sort ascending, click again to sort descending. Year Apr May Jun Jul Aug Sep Oct Season Mean 0 1 4 12 7 2 0 26 2023 0 0 1 10 0 3 M 14 2022 0 3 3 11 13 0 0 30 2021 0 0 9 8 8 0 0 25 2020 0 0 5 19 10 0 0 34 2019 0 0 4 14 5 2 1 26 2018 0 4 4 10 16 4 0 38 2017 0 3 3 8 2 1 0 17 2016 0 3 1 15 10 3 0 32 2015 0 0 3 6 8 3 0 20 2014 0 0 0 3 1 2 0 6 2013 0 2 2 15 1 1 0 21 2012 0 2 6 14 6 0 0 28 2011 0 0 3 14 2 0 0 19 2010 1 2 12 18 11 4 0 48 Monthly Number of Days Max Temperature >= 90 for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Year Apr May Jun Jul Aug Sep Oct Season Mean 0 1 3 9 6 2 0 22 1983 0 0 7 15 11 7 0 40 1982 0 0 1 10 1 0 0 12 1981 0 1 4 12 3 1 0 21 1980 0 1 3 8 12 3 0 27 1979 0 2 1 8 9 0 0 20 1978 0 1 3 8 4 0 0 16 1977 1 3 1 14 6 1 0 26 1976 2 0 7 2 4 0 0 15 1975 0 1 3 3 5 0 0 12 1974 1 2 2 10 3 0 0 18 1973 0 0 5 9 12 5 0 31 1972 0 0 0 16 4 1 0 21 1971 0 0 6 7 7 2 0 22 1970 0 2 2 5 8 5 0 22 Monthly Number of Days Max Temperature >= 90 for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Year Apr May Jun Jul Aug Sep Oct Season Mean 0 2 5 15 8 3 0 33 2023 2 1 1 14 5 4 M 27 2022 0 4 6 20 18 1 0 49 2021 0 4 12 11 13 1 0 41 2020 0 0 5 17 9 0 0 31 2019 0 1 4 14 4 3 1 27 2018 0 4 5 9 14 4 0 36 2017 0 3 5 9 2 3 0 22 2016 0 3 3 16 13 5 0 40 2015 0 2 4 11 13 5 0 35 2014 0 0 2 8 2 3 0 15 2013 0 2 4 15 3 1 0 25 2012 0 2 6 16 7 2 0 33 2011 0 1 4 22 4 0 0 31 2010 1 2 13 21 11 6 0 54 Monthly Number of Days Max Temperature >= 90 for Poughkeepsie Area, NY (ThreadEx) Click column heading to sort ascending, click again to sort descending. Year Apr May Jun Jul Aug Sep Oct Season Mean 0 1 1 6 3 1 0 12 1983 0 0 4 11 7 6 0 28 1982 0 0 0 10 0 0 0 10 1981 0 1 1 5 1 0 0 8 1980 0 0 3 6 6 3 0 18 1979 0 2 0 4 5 0 0 11 1978 0 0 1 4 3 0 0 8 1977 0 2 0 12 3 1 0 18 1976 3 0 1 0 0 0 0 4 1975 0 3 3 2 3 0 0 11 1974 0 0 1 5 0 0 0 6 1973 0 0 3 4 8 4 0 19 1972 0 0 0 10 2 0 0 12 1971 0 0 2 3 1 1 0 7 1970 0 0 0 5 7 1 0 13 Monthly Number of Days Max Temperature >= 90 for Poughkeepsie Area, NY (ThreadEx) Click column heading to sort ascending, click again to sort descending. Year Apr May Jun Jul Aug Sep Oct Season Mean 0 1 3 10 5 2 0 21 2023 2 0 2 7 0 1 M 12 2022 0 3 1 13 16 1 0 34 2021 0 1 9 4 6 0 0 20 2020 0 0 4 17 10 0 0 31 2019 0 0 1 12 2 1 0 16 2018 0 1 3 8 4 4 0 20 2017 0 2 4 3 1 2 0 12 2016 0 4 3 16 6 2 0 31 2015 0 0 0 5 10 6 0 21 2014 0 0 1 4 1 2 0 8 2013 0 3 4 11 0 1 0 19 2012 1 2 5 11 3 0 0 22 2011 0 0 3 10 2 0 0 15 2010 1 2 4 16 5 2 0 30

You can see from this old NYT article how Central Park used to be warmer than LGA when the instruments weren’t under the trees. The ASOS at LGA is right on the water away from the main terminals and taxiways. So they can easily get wind flow off that western portion off the Sound-East River. https://www.nytimes.com/1977/07/22/archives/vandals-in-central-park-forcing-weather-service-to-seek-new-site.html

You are mixing several things together. First,Tony is correct that the city center is warmer than the airports. Philly is in a swamp next to the Delaware River. So it’s not the greatest representation of the actual temperatures in Philly. I am not a fan of rooftop sites, but it’s not necessarily that they are biased warm vs ground level. Just look at the warmest temperatures in the NYC micronet. The street level sites are often the same or even warmer than rooftop. Plus the higher the rooftop site, the cooler the temperatures. So high enough can be introducing a cool bias. Newark is not significantly warmer than say Harrison or Freehold. NYC is definitely too cold since it’s the only US observing site under a dense tree canopy which biases the highs 2-5 degrees too cool. This wasn’t the case when the site received direct exposure before the 1990s. This was when NYC was typically warmer than LGA as mentioned but the NWS at the time. Ever wonder why the heatwaves before the 1990s had Central Park near the leader for high summer temperatures? Go measure the highs out on the Great Lawn and you would see this cool bias of the trees disappear.

Consistent extreme dew points and heat indices didn’t really become more frequent around until July 1995. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=76&network=NY_ASOS&station=ISP&season=summer&varname=dwpf&agg=mean&year=1893&w=bar&hours=0-23&_r=t&dpi=100&_fmt=png

You don’t even need to look at any of the discussions from the various agencies. The raw data is freely available on the internet. Forcing continues to be centered over the WPAC which is driving the current amplification of the pattern ahead of Lee. Much more of a Niña-like pattern for early September. Record early September heat in the East and major hurricanes approaching from the east are also more Niña-like.

Those point forecasts can be off by 10-20 miles in determining where the max sets up around Philly. So the upper 90s maxes around Philly have been spot on in the city center. Same goes for NJ. The coarse model resolution often shows the max temperatures 20-30 miles SW of Newark and Harrison. But the maxes are usually further NE. So I take the Euro NJ state temperature max and adjust it closer to the urban corridor around Newark.

We wouldn’t be seeing the strong Atlantic hurricane activity if the El Niño was having a big influence on the actual pattern.

We still haven’t seen a full coupling of the atmosphere when the trade winds and clouds are factored in. Also note how the forcing is struggling to make it east of the Dateline for another month. http://www.bom.gov.au/climate/enso/ while trade winds and Pacific cloudiness have not yet demonstrated sustained El Niño patterns. Overall, atmospheric indicators suggest the Pacific Ocean and atmosphere are not yet consistently reinforcing each other, as occurs during El Niño events.

95 at Philly international and 96 at Northeast Philly. So downtown Philly near the Franklin Institute was probably 97-98. But it can sometimes take time for the downtown Philly OBS to become available. When I go to the site, downtown Philly is only updated through July. That site runs a few degrees warmer than the airports. Monthly Data for July 2023 for Pennsylvania Click column heading to sort ascending, click again to sort descending. Name Station Type Highest Max Temperature HARRISBURG CAPITAL CITY AP WBAN 99 BRADDOCK LOCK 2 COOP 97 BIGLERVILLE COOP 97 Philadelphia Center City Area ThreadEx 97 PHILADELPHIA FRANKLIN INSTITUTE COOP 97 LANCASTER AIRPORT WBAN 96 SHIPPENSBURG COOP 96 CASHTOWN 1S COOP 96 CARLISLE WATER PLANT COOP 96 WILLIAMSPORT 2 COOP 96 LANDISVILLE 2 NW COOP 95 MIDDLETOWN HARRISBURG INT'L AP WBAN 95 CHARLEROI LOCK 4 COOP 95 PHILADELPHIA INTL AP WBAN 95 SAFE HARBOR DAM COOP 95 CONNELLSVILLE 2 SSW COOP 95 NORTHEAST PHILADELPHIA AIRPORT WBAN 95

The timing of the historic warmth that month matched the MJO 4-6 passage very well. The record warmth began to emerge around the 10th and lingered through the 27th. Plus it coincided with the very positive NAO and AO that month. We can often see lingering effects several days past the warmest MJO phases. Which lead to the 70° warmth around Christmas. Go to December 2015 in menu. https://www.nrcc.cornell.edu/regional/narrative/narrative.html

The mid-December MJO 4-6 forcing completely overpowered the whole Dateline forcing pattern leading to the historic SE Ridge and +13 temperature departures. The WPAC warm pool actually muted a super El Niño at least for a month. That’s what we have been dealing with to some extent with every El Niño attempt since then.

Newark on track for the first time since 1983 of having the warmest annual temperature without a tie in September. Monthly Highest Max Temperature for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Year Apr May Jun Jul Aug Sep Oct Season 1953 77 91 100 99 102 105 80 105 1993 82 93 102 105 100 100 82 105 1983 85 84 96 98 97 99 84 99 2018 84 94 96 98 96 98 82 98 2015 82 91 93 98 97 98 81 98 2010 92 95 98 103 98 98 79 103 1980 75 90 94 101 95 98 79 101 1989 79 89 96 99 97 97 80 99 1944 80 94 95 98 102 97 88 102 2013 85 94 96 101 91 96 89 101 1964 85 96 99 99 94 96 80 99 1931 71 93 96 96 96 96 86 96 2023 93 90 91 96 91 95 M 96

Yeah, the summer has seen increasing blocking which may be linked to the decreasing late spring snow cover in North America according to the paper. While winter has seen a decline, we have had some of the best winters for Greenland blocking since 2009 along with some of the lowest blocking seasons. So a much higher range.

Based solely on the historic Atlantic SSTs, we would finish the season with 200-250 ACE units. So if this Nino continues to have trouble coupling, we may approach those levels. It will be interesting to see how things turn out.

They have a nice tweet out today on the topic.

It’s all about the progression of model forecasts and seasonal trends. Always a bit uncertain as to when a seasonal trend will end and we go back to the long term pattern. I will give new AI model forecasts at ECMWF credit from a few days ago for seeing the stronger WAR ahead of the OP. Tomorrow may be the first time in a while that the warmest temperature of the year occurs in September. Someone in NJ could hit 100° which would be one of the latest instances in the season if they could pull it off. AI models at ECMWF brush the Cape this run. https://charts.ecmwf.int/catalogue/packages/ai_models/

Yeah, the AI versions of the Euro have come further west also due to the stronger WAR than forecast. Figures the WAR would wait until September to finally put in a cameo this year. Plus any UL to our west could tug the storm even further west in later runs. Now we are back to the forecast bias of underestimating he WAR longer range only to correct stronger the closer in we get. This has been out pattern for years after a brief break over the summer. Figures it would be so difficult to sustain that for long with the record SSTs offshore. New run stronger WAR Old run weaker WAR