bluewave

The backdoor pattern prevented us from having a +4 to +5 month like areas around the Great Lakes got.

Classic backdoor pattern with 58° here at KHVN and 82° for Philly. New Haven CLOUDY 58 Philadelphia PTSUNNY 82

90° maxes west of the backdoor yesterday. Monthly Data for April 2024 for New Jersey Click column heading to sort ascending, click again to sort descending. Name Station Type Highest Max Temperature SOMERSET AIRPORT WBAN 90 PHILADELPHIA/MT. HOLLY WFO COOP 90 MILLVILLE MUNICIPAL AIRPORT WBAN 90 PENNSAUKEN 1N COOP 90 Belvidere Area ThreadEx 90 BELVIDERE BRIDGE COOP 90 CALDWELL ESSEX COUNTY AP WBAN 90 ESTELL MANOR COOP 90 SEABROOK FARMS COOP 89 EWING 3 WNW COOP 89 NEW BRUNSWICK 3 SE COOP 89 New Brunswick Area ThreadEx 89 FLEMINGTON 5 NNW COOP 89 PHILLIPSBURG-EASTON BRIDGE COOP 89 SOUTH JERSEY REGIONAL AIRPORT WBAN 89 SUSSEX AIRPORT WBAN 88 MOORESTOWN 4 E COOP 88 TRENTON-MERCER AIRPORT WBAN 88 Trenton Area ThreadEx 88 HARRISON COOP 88 FREEHOLD-MARLBORO COOP 87 CHARLOTTEBURG RESERVOIR COOP 87 TETERBORO AIRPORT COOP 86 Atlantic City Area ThreadEx 86 Newark Area ThreadEx 86 CAPE MAY 2 NW COOP 86 ATLANTIC CITY INTL AP WBAN 86 NEWARK LIBERTY INTL AP WBAN 86 TETERBORO AIRPORT WBAN 86 BOONTON 1 SE COOP 86

A very backdoor April with LGA having the coolest averages relative to the means due to the easterly flow off the Long Island Sound. EWR….+1.7 NYC…..+2.0 LGA…..+0.1 JFK……+1.6 ISP……+0.7 BDR…..+0.8

The one way to avoid the higher property insurance and HOAs in Florida is to look into new construction which has better hurricane rated features not immediately at the shore. The average property insurance with a brand new roof and windows which are hurricane rated can be as low as 1500 a year. But properties with a roof older than 15 years can be very hard to insure with either outright rejections or rates over 6k. So if you live in an HOA the monthly fees reflect the master policy for the outside of the condos which has quadruped in some cases in recent years. So the key for buying a property down there is finding out exactly what your rates will be before you buy.

I can remember the big beach crowds before the season began. It gets really packed once the train crowds arrive from NYC. Gino’s is a goldmine with a line out the door as many people stop there first. It was my favorite pizza on Long Island. Now near New Haven it’s a pizza lovers paradise. Just had Modern pizza from New Haven over the weekend and it’s one of the best pizzas that I ever had.

https://judithcurry.com/2015/02/22/understanding-time-of-observation-bias/ At first glance, it would seem that the time of observation wouldn’t matter at all. After all, the instrument is recording the minimum and maximum temperatures for a 24-hour period no matter what time of day you reset it. The reason that it matters, however, is that depending on the time of observation you will end up occasionally double counting either high or low days more than you should. For example, say that today is unusually warm, and that the temperature drops, say, 10 degrees F tomorrow. If you observe the temperature at 5 PM and reset the instrument, the temperature at 5:01 PM might be higher than any readings during the next day, but would still end up being counted as the high of the next day. Similarly, if you observe the temperature in the early morning, you end up occasionally double counting low temperatures. If you keep the time of observation constant over time, this won’t make any different to the long-term station trends. If you change the observations times from afternoons to mornings, as occurred in the U.S., you change from occasionally double counting highs to occasionally double counting lows, resulting in a measurable bias. To show the effect of time of observation on the resulting temperature, I analyzed all the hourly temperatures between 2004 and 2014 in the newly created and pristinely sited U.S. Climate Reference Network (CRN). I looked at all possible different 24 hour periods (midnight to midnight, 1 AM to 1 AM, etc.), and calculated the maximum, minimum, and mean temperatures for all of the 24 hours periods in the CRN data. The results are shown in Figure 4, and are nearly identical to Figure 3 published in Vose et al 2003 (which was used a similar approach on a different hourly dataset). On average, observing temperatures (and resetting the minimum-maximum thermometer) in the early morning results in reading about 0.15 C cooler than if temperatures were observed at midnight. Observing temperatures in the late afternoon results in temperatures about 0.45 C warmer on average than if temperatures were observed at midnight. Switching from an afternoon time of observation to a morning time of observation would result in minimum, maximum, and mean temperatures around 0.6 C colder previously measured. What Would Happen to the Climate Reference Network if TOBs Changed? Another way to look at the impact of time of observation changes is to use the “perfect” Climate Reference Network (CRN) hourly data to see exactly what would happen if observation times were systemically changed from afternoon to morning. To do this I took CRN hourly data and randomly assigned 10 percent of stations to have a midnight time of observation, 20 percent of stations to have a 7 AM observation time, and 70 percent of stations to have a 5 PM observation time, similar to the U.S. Historical Climate Network (USHCN) prior to 1950. I then had 50 percent of the stations that previously had afternoon observation times shift to morning observation times between 2009 and the start of 2014. This is shown in Figure 5, and results in a time of observation shift quite similar to that of the USCRN shown in Figure 1, albeit over a 5 year period rather than a 50-year period. There is a cooling bias of about 0.5 C introduced to the conterminous U.S. temperature record from CRN data by shifting observation times from 5 PM to 7 AM in 50 percent of stations. Interestingly, there is a strong seasonal cycle in the TOBs bias, with the largest differences seen in February, March, and April, similar to what Karl et al 1986 found. This bias of 0.5 C is of similar magnitude in the minimum, maximum, and mean temperatures. It is slightly larger than the ~0.3 C TOBs adjustments made to USHCN data (shown back in Figure 2) for two reasons: first, the percent of stations shifting from afternoon to morning is slightly higher in my synthetic CRN data than what actually occurred in USHCN; second, not all observers actually record at 7 AM and 5 PM (they tend to range from 7-9 AM and 5-7 PM, and later morning and afternoon readings result in slightly less bias as shown in figure 4). It is clear that the shift from afternoon to morning observations in the United States introduced a large cooling bias of about 0.3 C in raw U.S. temperatures. As contiguous U.S. temperatures have risen about 0.9 C over the last century, not correcting for this bias would give us a significant underestimate of actual U.S. warming. While some commenters have hyperbolically referred to temperature adjustments as “the biggest science scandal ever”, the reality is far more mundane. Scientists are working their hardest to create the most accurate possible record of global temperatures, and use a number of methods including tests using synthetic data, side-by-side comparisons of different instruments, and analysis from multipleindependent groups to ensure that their results are robust. I’d suggest that those who doubt the efficacy of their approaches do what I did: download the data and take a look for yourself.

The tree growth over the ASOS has become so dense that Central Park hasn’t made it over 98° since 2012 which is a new record. Number of Consecutive Days Max Temperature < 99 for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Run Length Dates Period of record: 1869-01-01 to 2024-04-28 1 4302 2012-07-19 through 2024-04-28 2 4022 1966-07-14 through 1977-07-17 3 3260 1885-07-22 through 1894-06-24 4 2844 1903-09-19 through 1911-07-02 5 2212 1911-07-11 through 1917-07-30 6 1786 2005-08-14 through 2010-07-04 7 1763 1983-09-12 through 1988-07-09 8 1761 1957-07-23 through 1962-05-18 9 1476 1919-07-05 through 1923-07-19 10 1475 1944-08-12 through 1948-08-25 https://www.foxweather.com/weather-news/new-york-city-arguably-has-the-most-unique-weather-observations-in-america 1920 2021

The usual warm spots from around Philly NE into NJ should get very close to 90° ahead of the backdoor this afternoon.

Much cooler April than last year as we had a strong blocking pattern which muted the influence of the perma-ridge south of the Aleutians. Time Series Summary for NY CITY CENTRAL PARK, NY - Month of Apr Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Missing Count 1 2010 57.9 0 2 2023 57.6 0 3 2017 57.2 0 4 1941 56.8 0 5 2002 56.1 0 - 1981 56.1 0 - 1921 56.1 0 6 1969 55.9 0 7 2006 55.7 0 - 1991 55.7 0 8 1994 55.6 0 - 1945 55.6 0 9 2019 55.5 0 - 1985 55.5 0 - 1910 55.5 0 10 2005 55.1 0 - 1974 55.1 0 11 2008 55.0 0 - 1976 55.0 0 - 1968 55.0 0 - 1952 55.0 0 12 2012 54.8 0 13 2021 54.6 0 14 2009 54.5 0 - 1986 54.5 0 - 1980 54.5 0 15 2024 54.4 3 - 1915 54.4 0

We’ll probably need better climate models in the future to give us that answer. https://www.nature.com/articles/s41612-022-00301-2 This work must be open to the idea that climate models, as currently formulated, may be deficient in their representations of past and future changes in tropical Pacific climate. Until this issue is resolved, many aspects of future projections that are strongly influenced by the tropical Pacific – including future regional climate, teleconnected climate risks, and the oceanic uptake of CO2 – will be highly uncertain.

While it’s a bit early for me to start thinking about next winter, the winter warmth since the 15-16 super El Niño has been simply astounding. There had never been a sustained 9 winter period in our modern instrumental period back to the late 1800s this warm before in the Eastern US. My guess is that the shift is related to dramatic warming in Western Pacific which began back in 2014. This is in concert with more frequent and higher amplitude MJO 4-7 phases. Even with the El Niño this winter the Aleutians ridge near the Dateline was unusually strong. This has been a repeating theme since 15-16. It also works to amplify the ridge and warmth in the East. All the seasonal model winter forecasts since 15-16 have been significantly too cold. This is probably related to the models not having the capability to factor in the historic SST changes since 2014 in the Pacific when they have been making their seasonal forecasts. So it will be interesting to see if this pattern keeps repeating in coming winters or something happens to shift away from this persistent 9 winter pattern. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2022GL101078 The fundamental result of this study is that the first EOF of SST in the North Pacific has changed starting in 2014. For more than 20 years, the PDO has been used to describe the state of the North Pacific. However, since the marine heatwave of 2014, there have been remarkable changes to the dominant mode of SST in the North Pacific. The spatial pattern of the first EOF of SST from 1950 to 2021 is notably different from the PDO, suggesting that though the PDO served as a useful metric of SST variations until 2014 (Johnstone & Mantua, 2014), it may no longer be as effective a climate index for the North Pacific. From 1950 until the 2014 MHW, the first EOF remained consistent in its proportion of positive and negative regions with both taking up roughly half the area of the North Pacific (and with the positive region taken to be the eastern Pacific). When EOFs are calculated from 1950 to endpoints after 2014, the first EOF has a maximum positive region covering 77% of the North Pacific, with a PC indicating the largest anomalies on record. These changes to the first EOF/PC of North Pacific SST are nothing short of remarkable. In concert with these changes, the second EOF/PC of SST has also undergone profound evolution since 2014. This second EOF now accounts for approximately 18% of the variability, growing from 13% during the 1950–2013 period. The spatial structure of the second EOF now is positive over almost the entire basin, with a PC that has grown strongly positive in the last several years. Thus, the second EOF/PC describes warming over much of the Pacific not in the positive lobe of the first EOF.

Next few days we could see some localized pockets over .50 with the warm front.

I guess this is to be expected given the acceleration of ocean warming as per this recent study. But the timing of this most recent spike will probably need some further investigation. It would be interesting to know which specific variables were involved so we could forecast these individual temperature jumps more successfully.

It will be interesting to see what is causing the the global SSTs to peak a month later than average continuing at record levels.

You know spring is progressing when we stop getting afternoon highs in the 40s with rain behind the backdoor cold fronts. Looks like most areas away from the immediate shore will reach the 80s by Monday. Then a weak backdoor for Tuesday with highs still in the 60s and 70s eastern sections.

I had some interesting temperature observations during all my years back in Long Beach. One day we had a high of 85° through around 5pm while we were south of the sea breeze front. It was around 100° near NYC. A line of strong to severe storms formed and a gust frost developed. It shifted the winds to W to NW and my thermometer jumped from 85° to 97° in about 5 minutes. Another day the sea breeze front only made it to the boardwalk. It was in the upper 80s on the beach with a slight WSW flow and a westerly flow north of Shore road with mid 90s. But most days during the summer we were usually well south of the sea breeze front. Ambrose jets were very common with plenty of blowing sand right onto the streets near the beach.

I believe that 108° In Mineola during 2010 was probably the highest temperature on record for Long Island. But the site shut down in 2011. Ed was the president of the Long Island Weather Observers. The site was in operation from 1938 to 2011. His observations were featured every evening on News 12 for years. Cold Snap Tests Service Agencies The New York Times https://www.nytimes.com › New York › Long Island In Mineola, temperatures hit a low of 6 degrees on Dec. 23, according to Ed Lynt, president of the Long Island Weather Observers, a volunteer organization Time Series Summary for MINEOLA, NY - Jan through Dec Click column heading to sort ascending, click again to sort descending. Rank Year Highest Max Temperature Missing Count 1 2010 108 0 2 2001 105 32 3 1999 103 10 - 1966 103 0 5 1988 102 50 - 1975 102 1 - 1948 102 1 8 2002 101 0 - 1973 101 0 - 1968 101 0 - 1952 101 0 12 2006 100 1 - 1993 100 8 - 1991 100 0 - 1957 100 12 - 1955 100 3

Usually somewhere between JFK and LGA eastward along the LIE out to near Commack just north and west of where the sea breeze front sets up.

Even areas of Long Island closer to the LIE could reach the 80s on Monday ahead of any backdoor cold front.

The winter was dominated by the record polar vortex over the Arctic which got driven south by the strong -EPO block in early May.

My guess is that the much stronger spring blocking at times in recent years has been compensating to some extent. The hard freeze last May over the interior occurred with one of the strongest -EPO +PNA blocks on record for that time of year. But the stronger spring blocking at times can’t affect the earlier arrival of spring. So we get these overlaps leading to damaging freezes in susceptible arras.

Figures the first record low of the year down to 33° at Islip would wait until late April. https://www.weather.gov/wrh/timeseries?site=kisp Islip Low 33

You are missing the point that I made. The first 70° and 80° degree days of the season are becoming earlier at a faster rate than the last freeze is becoming earlier. So this creates more damaging freeze potential in the spring due to the increasing overlap. This is why the most damaging interior Northeast freeze on record for the spring occurred in May 2023. This works for many stations across the Northeast where the spring bloom is becoming earlier faster than the last freeze is becoming earlier. Some spots have a 3 week to one month faster start to spring while the last freeze is still within a week of where it was during the 1951-1980 climate normals period. Now if you go back to the late 1800s off course the last freeze was later. But that really isn’t relevant to the current day agricultural interests which have been sustaining spring freeze losses. We have also seen this is the Southeast with earlier starts to spring in February only to be subject to damaging freezes in March. This has been getting more attention from the literature in Europe recently but the same thing happened in the Northeast last May. https://www.worldweatherattribution.org/human-caused-climate-change-increased-the-likelihood-of-early-growing-period-frost-in-france/ In early April 2021 several days of severe frost affected central Europe following an anomalously warm March. This led to very severe damages in grapevine and fruit trees, particularly in France, where young leaves had already unfolded in the warm early spring. Using published peer-reviewed methods we analysed how human-induced climate change affected the temperatures as extreme as observed in spring 2021 over central France, where many vineyards are located. We found that although climate change made the temperatures of the observed event less cold than they would have been without the burning of fossil fuels over the last centuries, the fact that climate change has also led to an earlier start of the growing season means that frost damage in young leaves has become more likely due to human-induced climate change. https://ny1.com/nyc/all-boroughs/ap-top-news/2023/06/14/federal-assistance-sought-for-northeastern-vineyards-orchards-hit-by-late-frost SHELBURNE, Vt. (AP) — Vineyards and apple orchards across the Northeast are still gauging damage from a late-season frost in May that wiped out a third to most of the crop for some growers who say it’s the worst frost damage they have ever seen. Some states are seeking federal disaster declarations, which would make low-interest loans and other programs available to affected growers, while agriculture officials across the region are contemplating together asking the U.S. Department of Agriculture for direct aid to farmers. In southern Vermont, Scott Farm Orchard lost up to 90% of its apple crop when the temperature dipped to 25 degrees Fahrenheit (minus 3 degrees Celsius) for five hours on May 18. At the northern end of the state, Shelburne Vineyards in Shelburne, Vermont, lost about 50% of its grape crop, which is potentially a half-million dollar revenue loss, according to head wine grower and vineyard manager Ethan Joseph. To make up for lost production, Shelburne Vineyards plans to buy additional grapes at a time when its overall costs this year will be higher due to the frost, Joseph told The Associated Press. The vineyard has wine in stock to sell and it's not off the table that it could raise prices, he said. “We’ve never seen this kind of freeze event, certainly in the history of the vineyard,” Joseph said. “I’ve been here for 16 years. We’ve never seen anything like it.” The widespread frost hit the large wine-producing region of the Finger Lakes in upstate New York where it's estimated about half of the grape crop was lost regionwide, according to Kyle Anne Pallischeck, executive director of the Finger Lakes Wine Alliance. Depending on their location, some vineyards were hit hard and others had little to no damage. Vineyard owners say it's still too early to tell what the final financial impact will be. “I’ve been in this almost 40 years, doing it full-time and this is by far and away the worst,” said David Stamp, vineyard manager of Lakewood Vineyards, in Watkins Glen, New York, of the frost damage. He estimated their total crop loss at about 30% to 40% though it's tough to tell since the damage is scattered throughout the vineyards. “I mean, if you put all the years together that we’ve had any damage it’s not even a quarter of what this is,” he said. The losses will mean shorter supplies of certain wines next year and higher prices for apples this year. Some vineyards and orchards are having to reduce staff. Keuka Lake Vineyards, in Hammondsport, New York, estimates it lost between 50% and 65% of its crop, said Mel Goldman, owner and vineyard manager. “We lost a lot,” Goldman said, adding it will take a few weeks before a final verdict as the vines produce secondary buds and shoots that could bear. The last freeze at Newark hasn’t changed since 1950 but the first 70° and 80° days of the season are arriving much earlier.

The main challenge for the area is that the last freeze date is similar to 1951-1980 but first 70s and 80s of spring are arriving much earlier. So this has lead to the damaging spring freezes across the northeast especially in the interior. The historic damaging freeze last May to our north matched the pattern of early season warmth causing blooms which were followed by a damaging hard freeze. We can understand that as the climate continues to warm spring will arrive earlier with the quicker blooms. But the last freeze date has not changed as much and needs some further investigation. My guess is that the much stronger spring blocking from the EPO to NAO regions recently is allowing the last freeze date to remain more constant relative to earlier eras. I will use Newark as an example of this pattern that shows up to varying degrees across the region. Newark 2010-2023 Last 32°…. 04-04…last 30s…04-21 First 70°…..03-07…first 80°….03-31 1951-1980 Last 32°…..04-04…..last 30s…04-22 First 70°.….03-26….first 80°…..04-22