bluewave

We started getting smoke last May as you can see on the NWS post back on May 22nd and it peaked in early June. The big story since then has been how wet the pattern has been. Most of the warmer season months have been cooler and the colder season months warmer. This current global temperature spike put a record amount of water vapor into the atmosphere. NYC May 2023…-0.5 Jun 2023...-2.0 Jul 2023…..+1.5 Aug 2023…-1.1 Sep 2023…+0.2 Oct 2023….+2.6 Nov 2023….-1.3 Dec 2023….+5.5 Jan 2024…..+3.3 Feb 2024…..+4.2 Mar 2024…..+5.3 Apr 2024…..+1.9 May 2024…..-0.4

Recent winters have been overpowered by the record WPAC warm pool along the equator and east of Japan. So we get the repeating MJO 4-7 phases. This spring saw the +IOD reduce convection enough near the Maritime continent so we got the solid MJO 8 pattern. That lingering influence is what we have had since March 20th. The pattern could continue at least through the Memorial Day weekend according to the Euro. It’s showing a continuation of the deep -PNA trough and lingering trough over the Northeast.

This happens to be one of the very few months since the 15-16 super El Niño with a trough near the East Coast while there is a deep -PNA trough in the West. So something changed this month to go against the long term pattern. Figures a pattern like this would wait until May and not happen in the winter. It even left a decent cold pool to our east. Most other months like this over the last decade would have had a strong WAR or Southeast ridge pattern.

Last May didn’t feel like it was that sunny due to the record amount of wildfire smoke. It peaked in early June. I will take this kind of pattern any day over that really poor air quality.

So far ISP is tied for the cloudiest May at least through the first half of the month. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=45&network=NY_ASOS&zstation=ISP&hour=12&year=2024&month=5&_r=t&dpi=100&_fmt=png

Another issue with Chester County is that it’s pretty small and new stations don’t come online to replace the older retiring ones. There are many reporting gaps especially with the COOP stations. I noticed that Phoenixville hasn’t been reporting as reliably over recent years as it did in the past. It’s one of the warmer spots in the county. When they were reporting more regularly from 2005 to 2015 they actually had more 90° days than the Philadelphia International Airport. Data for January 1, 2005 through December 31, 2015 Click column heading to sort ascending, click again to sort descending. Name Station Type Number of Days Max Temperature >= 90 NORRISTOWN COOP 419 Philadelphia Center City Area ThreadEx 407 PHILADELPHIA FRANKLIN INSTITUTE COOP 407 YORK 3 SSW PUMP STN COOP 376 PHOENIXVILLE 1 E COOP 342 NORTHEAST PHILADELPHIA AIRPORT WBAN 332 Philadelphia Area ThreadEx 321 PHILADELPHIA INTL AP WBAN 321 SHIPPENSBURG COOP 303

Yeah, this is essentially one big science experiment that is being run on the climate with many of the finer details not being known until after they happen.

The global climate models are just general tools which show a range of global temperatures for varying amounts of Co2 emissions. They are not regional climate models. That’s why so many of the changes we have been seeing weren’t forecast. Such as the WPAC warming faster than the EPAC leading to a La Niña background pattern and more MJO 4-7 phases. Details about the NAO becoming more positive during the winter and negative in spring and summer weren’t forecast either. Plus the highs to the east of New England with more onshore flow during the summer and record SE ridge most of the year came as a surprise to us. The weather patterns have been changing faster than our computer modeling have been able to keep up with .

The weekend looks like the easterly flow will continue. Plenty of clouds around on Saturday. But models not showing much rain only a few showers and maybe some patchy drizzle in spots. Sunday may be the best chance for the clouds to break especially the further north you get.

Looks like northern portions of the Northeast and Canada will have warmer departures than us next 10 days as the onshore flow continues.

Another day with the lower max driving the daily cool departure. TEMPERATURE (F) TODAY MAXIMUM 64 1256 PM 90 1900 71 -7 74 MINIMUM 59 711 AM 42 1920 55 4 52 1947 AVERAGE 62 63 -1 63

Bradford, PA far from any UHI influence has been warming even faster than Philly over the last 30 years. Bradford, PA continues to be one of the fastest warming parts of the state. The minimums have risen +3.5° since 1994 and the maximums at +3.2°.

The real impact of UHI has been around for over 100 years in Philly so starting in 1970 or 1994 makes no difference. Chubbs has shown the errors in the way that you have put together the Chesco data. Remember global emissions and temperatures really began to accelerate around 1980. Rural locations have been warming at the same rate as urban ones since then.

Euro joining the GFS and GEM with more onshore flow potential next week. New run Old run

The rise in minimum temperatures at the airport is nearly identical to the one in Mt Holly at the NWS forecast office over the last 30 years. The population at Mt. Holly around 25 miles to the east has remained nearly steady at 10k as the population in Philadelphia has held steady around 1.5 million. It doesn’t appear that the Philadelphia UHI intensity has changed much in 30 years at the airport. So all the warming over the last 30 years is the result of a steadily warming climate and not a local increase in UHI intensity at the airport. Philadelphia International Airport 30yr minimum temperature rise +2.6°F. Mt.Holly NWS WFO 30 year minimum temperature rise +2.8°F

The regime shift occurred in 2007 to a much thinner sea ice state and was not forecast ahead of time. The ice free extent forecast by 2013 was an outlier that most agencies like the NSIDC never bought into. Remember there was no alarm in the early 2000s before the major shift in 2007. Complacency turned out to be the greater risk as the thickness and age of the ice has not recovered to pre-2007 levels. https://www.nature.com/articles/s41586-022-05686-x Manifestations of climate change are often shown as gradual changes in physical or biogeochemical properties1. Components of the climate system, however, can show stepwise shifts from one regime to another, as a nonlinear response of the system to a changing forcing2. Here we show that the Arctic sea ice regime shifted in 2007 from thicker and deformed to thinner and more uniform ice cover. Continuous sea ice monitoring in the Fram Strait over the last three decades revealed the shift. After the shift, the fraction of thick and deformed ice dropped by half and has not recovered to date. The timing of the shift was preceded by a two-step reduction in residence time of sea ice in the Arctic Basin, initiated first in 2005 and followed by 2007. We demonstrate that a simple model describing the stochastic process of dynamic sea ice thickening explains the observed ice thickness changes as a result of the reduced residence time. Our study highlights the long-lasting impact of climate change on the Arctic sea ice through reduced residence time and its connection to the coupled ocean–sea ice processes in the adjacent marginal seas and shelves of the Arctic Ocean. Our analysis demonstrates the long-lasting impact of climate change on Arctic sea ice through reduced residence time, suggesting an irreversible response of Arctic sea ice thickness connected to an increase of ocean heat content in areas of ice formation. The large reduction of summer ice extent in the Alaskan and Siberian sectors in 2005 and 2007 triggered intensive ice–albedo feedback42,45 and initiated the perennial increase of ocean heat content in these areas44. This resulted in the stepwise reduction of residence time of sea ice in the Siberian sector of the Arctic, and hence a nonlinear response of the system.

Just got a heavier downpour here just to the east of KHVN. More heavier downpours are showing up on radar to the south of Long Island. So somebody in the eastern zones could go over 2” like the HRRR suggests.

The biggest restrictions on where people can afford to live are being governed by insurance companies rapidly increasing rates in the highest risk areas.

Similar to the way that people moving into higher risk areas compounds the damages caused by the increased extreme weather with climate change.

Another issue as a global society is that we tend to think linearly about about important topics like climate change. But the challenge is non-linear shifts are part of climate change. Our models aren’t good at detecting these details. These important threshold temperatures at which we can see an abrupt shifts aren’t well forecast ahead of time. It’s usually after they have occurred that we take notice of them.

Yeah, a +2C to +3C increase would lock in much higher sea levels. But the key is how long it would take for this to occur. If we were to ever get the expected 200 years of sea level rise in just 20 years in coming decades, then it would set off mass migrations across the planet away from the coastal zones. Not sure if we would get much advanced notice of a rapid melt pulse since our current batch of models are still incomplete. https://www.theguardian.com/environment/2023/apr/05/ice-sheets-collapse-far-faster-than-feared-study-climate-crisis Ice sheets can collapse into the ocean in spurts of up to 600 metres (2,000 feet) a day, a study has found, far faster than recorded before. Scientists said the finding, based on sea floor sediment formations from the last ice age, was a “warning from the past” for today’s world in which the climate crisis is eroding ice sheets. They said the discovery shows that some ice sheets in Antarctica, including the “Doomsday” Thwaites glacier, could suffer periods of rapid collapse in the near future, further accelerating the rise of sea level. The rising oceans are among the greatest long-term impacts of global heating because hundreds of major cities around the world are on coastlines and are increasingly vulnerable to storm surges and flooding. The West Antarctic ice sheet may already have passed the point at which major losses are unstoppable, which will lead eventually to metres of sea level rise. “Our research provides a warning from the past about the speeds that ice sheets are physically capable of retreating at,” said Dr Christine Batchelor at Newcastle University in the UK, who led the research. “It shows that pulses of rapid retreat can be far quicker than anything we’ve seen so far.” These pulses translate into sea level rise and could be really important for sea defences,” she said. The rate of loss was critical if, for example, a rise expected over 200 years could actually occur in 20 years, Batchelor said. The research could also be used to enable computer models to make better predictions about future ice loss.

People want to know when the nations of the world will finally start addressing climate change. The answer is when the cost of business as usual gets too high. My guess is that between now and 2040 the damages from climate change to the economy will result in a shift in consciousness about the environment. While we are probably committed to +2C to +3C of warming, I think we can still avoid a PETM +5C to +8C scenario.

The record warm winter pattern lingered until around St.Patrick’s day giving us the warmest March 1-17th on record. Then the spring blocking pattern kicked in which has been a dominant feature in recent years. So the average high temperature ranking with all the clouds, rain, and onshore flow dropped down to 22nd place over this period. Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Ending Date Mean Avg Temperature Mar 1 to Mar 17 Missing Count 1 2024-03-17 51.1 0 2 1973-03-17 50.3 0 3 2016-03-17 49.0 0 4 2012-03-17 48.3 0 5 1977-03-17 48.1 0 6 2020-03-17 47.9 0 7 2000-03-17 47.8 0 8 1946-03-17 46.3 0 9 1990-03-17 46.0 0 10 2010-03-17 45.9 0 Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Ending Date Mean Max Temperature Mar 18 to May 14 Missing Count 1 2010-05-14 67.8 0 2 1985-05-14 66.5 0 3 2023-05-14 66.3 0 4 2012-05-14 66.1 0 5 1945-05-14 65.9 0 6 2021-05-14 65.3 0 7 1994-05-14 65.2 0 8 1949-05-14 65.1 0 9 1976-05-14 65.0 0 10 1986-05-14 64.7 0 11 2006-05-14 64.2 0 - 1938-05-14 64.2 0 12 1993-05-14 64.0 0 13 1987-05-14 63.8 0 - 1968-05-14 63.8 0 14 1981-05-14 63.6 0 15 1991-05-14 63.5 0 16 1963-05-14 63.4 0 - 1957-05-14 63.4 0 17 2004-05-14 63.3 0 18 2001-05-14 63.2 0 - 1979-05-14 63.2 0 19 2000-05-14 63.1 0 - 1969-05-14 63.1 0 - 1946-05-14 63.1 0 20 2015-05-14 63.0 0 - 1999-05-14 63.0 0 - 1942-05-14 63.0 0 21 1959-05-14 62.9 0 22 2024-05-14 62.8 0

The wild card for next weeks warm up will be how close to the coast the upper low gets. The Euro is the most optimistic and gets into a deeper SW flow and higher temperatures. The GFS and GEM hold into more onshore flow especially near the immediate coast and aren’t as warm. So the position of the upper low will determine the ceiling for high temperatures.

This month top 10 warmth at a station like Newark with a longer period of record starts at +2.9 like they got back in 2022. Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of May Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Departure 1 1991 68.9 0 2 2015 68.2 0 3 1965 67.3 0 4 1985 67.1 0 5 1993 67.0 0 6 2018 66.9 0 7 1986 66.6 0 8 2012 66.4 0 9 2004 66.3 0 10 2022 66.2 +2.9 - 2010 66.2 0