bluewave

The Euro has low 90s temperatures with low 70s dew points on Wednesday. So the heat indices will soar well into the 90s away from the shore where there will be a strong sea breeze. Hopefully, the convection holds together down to the coast for some much needed rainfall in the evening.

Memorial Day may end up being the best day of the entire holiday weekend.

It would be interesting to see how many more 100° days we would have had without the big increase in agriculture in those areas. https://www.sciencemag.org/news/2018/02/america-s-corn-belt-making-its-own-weather The United States’s Corn Belt is making its own weather By Kimberly HickokFeb. 16, 2018 , 12:05 PM The Great Plains of the central United States—the Corn Belt—is one of the most fertile regions on Earth, producing more than 10 billion bushels of corn each year. It’s also home to some mysterious weather: Whereas the rest of the world has warmed, the region’s summer temperatures have dropped as much as a full degree Celsius, and rainfall has increased up to 35%, the largest spike anywhere in the world. The culprit, according to a new study, isn’t greenhouse gas emissions or sea surface temperature—it’s the corn itself. This is the first time anyone has examined regional climate change in the central United States by directly comparing the influence of greenhouse gas emissions to agriculture, says Nathan Mueller, an earth systems scientist at the University of California (UC), Irvine, who was not involved with this study. It’s important to understand how agricultural activity can have “surprisingly strong” impacts on climate change, he says. The Corn Belt stretches from the panhandle of Texas up to North Dakota and east to Ohio. The amount of corn harvested in this region annually has increased by 400% since 1950, from 2 billion to 10 billion bushels. Iowa leads the country for the most corn produced per state. Get more great content like this delivered right to you!To see whether this increase in crops has influenced the region’s unusual weather, researchers at the Massachusetts Institute of Technology in Cambridge used computers to model five different 30-year climate simulations, based on data from 1982 to 2011. First, they compared simulations with high levels of intense agriculture to control simulations with no agricultural influence. Unlike the real-life climate changes, the control simulations showed no change in temperature or rainfall. But 62% of the simulations with intense agriculture resulted in temperature and rainfall changes that mirror the observed changes, the team reports this week in Geophysical Research Letters. Map of the central United States, showing changes in rainfall during the last third of the 20th century. Areas of increased rainfall are shown in green, with darker colors representing a greater increase. MASSACHUSETTS INSTITUTE OF TECHNOLOGY The team then compared its results to historical global simulations from the World Climate Research Programme (WCRP), an international program for the coordination of global climate research sponsored by the International Council for Science, the World Meteorological Organization, and the Intergovernmental Oceanographic Commission of UNESCO. WCRP’s models take into account greenhouse gas emissions and other natural and humanmade influences, but do not consider agricultural land use. When researchers ran the numbers for the Corn Belt, the global models fell short of reality: They predicted both temperature and humidity to increase slightly, and rainfall to increase by up to 4%—none of which matches the observed changes. Other climate simulations that use sea surface temperature variation didn’t match observed changes, either. Those simulations matched historical data until 1970; after that, the simulations predicted temperatures to keep increasing, rather than decreasing as they did in reality. This is a strong indication that agriculture, and not changing sea surface temperature, caused the regional changes in climate during the last third of the 20th century, the researchers say. “The [influence] of agriculture intensification is really an independent problem from greenhouse gas emissions,” says Ross Alter, lead author of the study and now a meteorologist with the U.S. Army Corps of Engineers in Hanover, New Hampshire. In fact, Alter says, heavy agriculture likely counteracted rising temperatures regionally that might have otherwise resulted from increasing greenhouse gas emissions. One other place that shows a similar drop in temperatures, he notes, is eastern China, where intensive agriculture is widespread. But how does agriculture cause increased rainfall and decreased temperatures? The team suspects it has to do with photosynthesis, which leads to more water vapor in the air. When a plant’s pores, called stomata, open to allow carbon dioxide to enter, they simultaneously allow water to escape. This increases the amount of water going into the atmosphere and returning as rainfall. The cycle may continue as that rainwater eventually moves back into the atmosphere and causes more rainfall downwind from the original agricultural area. Rong Fu, a climate scientist at UC Los Angeles, agrees with the team’s assessment. She also thinks that though human influence might be “greater than we realize,” this regional climate change is probably caused by many factors, including increased irrigation in the region. “This squares with a lot of other evidence,” says Peter Huybers, a climate scientist at Harvard University, who calls the new study convincing. But he warns that such benefits may not last if greenhouse gas emissions eventually overpower the mitigating effect of agriculture. Alter agrees, and says it’s unlikely that the large increases in U.S. crop production during the 20th century will continue. Other scientists have voiced concern that agricultural production could soon be reaching its limit in many parts of the world. “Food production is arguably what we’re more concerned about with climate change,” Mueller says. And understanding how agriculture and climate will continue to affect one another is crucial for developing projections for both climate and agricultural yields. “It’s not just greenhouse gasses that we need to be thinking about.”

The bulk of the rain on the 12z Euro is Friday into Friday night. Some lingering showers on Saturday. But the weekend looks cool with plenty of easterly flow. This past weekend when we reached the mid 90s will turn out to have been the best beach weekend of May.

Central Park is a great place for weather observations provided that the ASOS is placed in an open area away from trees. The problem with the Central Park site is that it was no longer maintained after the early 90s. Since the early 90s, is has been tucked in the deep shade under the trees. So the lack of direct sunlight results in afternoon highs that are 2° to 3° cooler than they used to be prior to the 90s. So this created a break in continuity from earlier observations. As for the airports, the ASOS units are placed on grassy surfaces. While there is plenty of concrete at the airports, there really isn’t any more or less than the surrounding neighborhoods where the people live. But since the airports are located on the water, they are prone to sea breezes. So there are neighborhoods around NYC metro that can be hotter depending on wind direction. Central Park before the sensor was blocked by trees Most recent photo as of 2013 under trees and violating the ASOS handbook sitting rules

The higher scoring Euro and CMC are dry for the Memorial Day weekend. They bring in the rain for Friday and Friday night. But it looks like a cool Sat to Mon with plenty of easterly flow. The big high east of New England is back again as we start June.

https://www.washington.edu/news/2020/12/15/a-i-model-shows-promise-to-generate-faster-more-accurate-weather-forecasts/ December 15, 2020 A.I. model shows promise to generate faster, more accurate weather forecasts Hannah Hickey UW News Today’s weather forecasts come from some of the most powerful computers on Earth. The huge machines churn through millions of calculations to solve equations to predict temperature, wind, rainfall and other weather events. A forecast’s combined need for speed and accuracy taxes even the most modern computers. The future could take a radically different approach. A collaboration between the University of Washington and Microsoft Research shows how artificial intelligence can analyze past weather patterns to predict future events, much more efficiently and potentially someday more accurately than today’s technology. The newly developed global weather model bases its predictions on the past 40 years of weather data, rather than on detailed physics calculations. The simple, data-based A.I. model can simulate a year’s weather around the globe much more quickly and almost as well as traditional weather models, by taking similar repeated steps from one forecast to the next, according to a paper published this summer in the Journal of Advances in Modeling Earth Systems. “Machine learning is essentially doing a glorified version of pattern recognition,” said lead author Jonathan Weyn, who did the research as part of his UW doctorate in atmospheric sciences. “It sees a typical pattern, recognizes how it usually evolves and decides what to do based on the examples it has seen in the past 40 years of data.” Although the new model is, unsurprisingly, less accurate than today’s top traditional forecasting models, the current A.I. design uses about 7,000 times less computing power to create forecasts for the same number of points on the globe. Less computational work means faster results. That speedup would allow the forecasting centers to quickly run many models with slightly different starting conditions, a technique called “ensemble forecasting” that lets weather predictions cover the range of possible expected outcomes for a weather event – for instance, where a hurricane might strike. “There’s so much more efficiency in this approach; that’s what’s so important about it,” said author Dale Durran, a UW professor of atmospheric sciences. “The promise is that it could allow us to deal with predictability issues by having a model that’s fast enough to run very large ensembles.” Co-author Rich Caruana at Microsoft Research had initially approached the UW group to propose a project using artificial intelligence to make weather predictions based on historical data without relying on physical laws. Weyn was taking a UW computer science course in machine learning and decided to tackle the project. “After training on past weather data, the A.I. algorithm is capable of coming up with relationships between different variables that physics equations just can’t do,” Weyn said. “We can afford to use a lot fewer variables and therefore make a model that’s much faster.” To merge successful A.I. techniques with weather forecasting, the team mapped six faces of a cube onto planet Earth, then flattened out the cube’s six faces, like in an architectural paper model. The authors treated the polar faces differently because of their unique role in the weather as one way to improve the forecast’s accuracy. The authors then tested their model by predicting the global height of the 500 hectopascal pressure, a standard variable in weather forecasting, every 12 hours for a full year. A recent paper, which included Weyn as a co-author, introduced WeatherBench as a benchmark test for data-driven weather forecasts. On that forecasting test, developed for three-day forecasts, this new model is one of the top performers. The data-driven model would need more detail before it could begin to compete with existing operational forecasts, the authors say, but the idea shows promise as an alternative approach to generating weather forecasts, especially with a growing amount of previous forecasts and weather observations. Weyn is now a data scientist with Microsoft’s weather and finance division. This research was funded by the U.S. Office of Naval Research and a Department of Defense graduate fellowship. https://www.wsj.com/articles/how-ai-can-make-weather-forecasting-less-cloudy-11617566400 Sid Boukabara, principal scientist at the National Oceanic and Atmospheric Administration’s Center for Satellite Applications and Research, thinks those gains will be significant. “For certain components, it could be 10 times more efficient to 1,000 times more efficient.” But it is too early to know how much this will enhance the accuracy of numerical weather prediction as a whole. For instance, the European Center for Medium-Range Weather Forecasts currently simulates the globe as a grid of squares that are 9 kilometers on a side (roughly 5 miles) and stacked 137 layers up into the atmosphere. Deputy Director Peter Bauer says each step up in detail requires an exponential increase in electricity: The center’s newest supercomputer in Bologna, Italy, will consume as much power as 6,000 households. He and his colleagues are quickly approaching the limits of what they can afford or justify, he says. This year—relying on AI methods to boost efficiency—the center will begin developing a new global model at a 1-kilometer resolution that will bring storms and oceanic eddies into better focus, says Dr. Bauer. “Bigger and faster machines give us ever greater computing power, but we need to radically change the code we run on them to be able to use them effectively.”

All that we know is the new default winter and summer patterns since the super El Niño in 15-16. Warmer than normal winters with above normal snowfall. The two exceptions were the below normal snowfall winters in 18-19 and 19-20. But they were still warm. The summers since 16 have been warmer than average and more humid. The only outlier was the cooler 2017 summer but it was still humid. So it’s very difficult to know ahead of time when the coming season is going to deviate from recent experience.

No problem. The Central Park sensors used to be located in direct sunlight before the trees created deep shade. My rough calculation is that this has created an artificial 2° to 3° average maximum temperature summer JJA cooling since 1971. Notice how the mean summer high temperature increase at the other local stations since 1971 has been +2.7°.The high temperature staying steady at NYC instead of increasing was a function of trees blocking the sun. 1971 to 2020 summer JJA high temperature increase NYC….82.9….82.9…..0.0 LGA…..81.0….84.9….+3.9 EWR….83.4….85.4….+2.0 JFK…..80.1…..82.3..+2.2 ISP…….78.5…..81.6..+3.1 HPN….79.0….81.6…+2.6 BDR….79.1…..81.4…+2.3

The overgrowth of vegetation blocking the sensors has been well known for a while now. They would need to move the ASOS to a clearing away from any trees. The video below shows the correct sitting of weather sensors in parks or more rural settings. https://www.ncdc.noaa.gov/cdo-web/datasets/GHCND/stations/GHCND:USW00094728/detail Obstruction Descriptions OBSTRUCTIONS BEGIN DATE¹ END DATE¹ TREES 2021-04-06 Present TREES 2017-08-01 2021-04-06 TREE 020-340 deg 25-25 ft 20-54 deg 2016-06-15 2017-08-01 HYGR 090/4 TREES ENCIRLCE/25/20-54 IN FENCED ENCOLSURE 50 FT X 25 TH 1995-06-27 2016-06-15 UNIV 050/4 CRS 180/9 H083 SENSOR 200/8 TB 220/20 TREES ENCIRCLE/25/20-54 EQUIPMENT IN FENCED ENCLOSURE 50 FEET X 25 FEET 1992-01-01 1995-06-27 http://www.weather2000.com/ASOS/NYC_ASOS.html Central Park Weather: Vegetative Overgrowth Affecting Weather Readings - WABC-TV (New York-WABC, August 22, 2003) - Forecasting the weather is not easy. Government equipment can often be blamed for giving faulty weather information. As Bill Evans explains, a big culprit may be some of the equipment buried in Central Park. Rainfall, snowfall, and the temperature are all vital information recorded 24 hours a day at the weather station located in the heart of Central Park. But meteorologists like Michael Schlacter have serious concerns about the accuracy of the stations data. It sits amid overgrown vegetation and he says thats the problem. The leaves can trigger snow gauges and trees can warp rain and wind measurements. On this hot day, a temperature gauge is in the shade instead of direct sunlight. Michael Schlacter, Weather 2000: "Its kind of like driving a car without a speedometer, odometer, and gas gauge. You are running with false information." The weather instruments at Belvedere Castle have long adorned the top. There used to be a government meteorologist here in the city to keep an eye on them. But now the nearest meteorologist is 60 miles that way. But National Weather Service meteorologists say they knew the weather readings in the park would never be as keenly accurate as the ones at the airports where guidelines prevent foliage from being within 100 feet of the station. Schlacter: "We knew that at times we would have flaky readings, that leaves would fall in gauges, that we would have problems with visibility sensors." [NWS Meteorologist-in-Charge Michael] Wyllie says the weather station is there because it was historically significant to maintain its presence in the park. He says theres been a lot of growth because of the wet spring at so much in fact that temperatures have routinely been recorded lower in the park than at the airports. Wyllie: "We are actually having a micro climate system there because of the vegetation." Imperfect perhaps but nonetheless the system provides the official record of weather for the country's largest city. And Michael Schlacter says its a city that deserves better. Schlacter: "I think New Yorkers deserve a lot better, and I think they deserve the best weather station money can buy." Copyright 2003 ABC Inc., WABC-TV Inc.

This weekend actually looks like our last dry heat for a while. The next warm up on Wednesday is forecast to be more humid. So we may get back to the familiar 70° dewpoints. It would fit with the guidance showing better rain chances coming up.

The 36° degree difference between the high and low at JFK is the 2nd greatest on record for May. Just goes to show how dry it has been. This is closer to normal for Tucson, Arizona. CLIMATE REPORT NATIONAL WEATHER SERVICE NEW YORK, NY 434 PM EDT SAT MAY 22 2021 ................................... ...THE KENNEDY NY CLIMATE SUMMARY FOR MAY 22 2021... VALID TODAY AS OF 0400 PM LOCAL TIME. CLIMATE NORMAL PERIOD 1991 TO 2020 CLIMATE RECORD PERIOD 1948 TO 2021 WEATHER ITEM OBSERVED TIME RECORD YEAR NORMAL DEPARTURE LAST VALUE (LST) VALUE VALUE FROM YEAR NORMAL ................................................................... TEMPERATURE (F) TODAY MAXIMUM 94R 148 PM 94 1992 70 24 73 MINIMUM 58 243 AM 43 1990 54 4 52 AVERAGE 76 62 14 63 ...THE TUCSON AZ CLIMATE SUMMARY FOR MAY 21 2021... CLIMATE NORMAL PERIOD 1991 TO 2020 CLIMATE RECORD PERIOD 1895 TO 2021 WEATHER ITEM OBSERVED TIME RECORD YEAR NORMAL DEPARTURE LAST VALUE (LST) VALUE VALUE FROM YEAR NORMAL ................................................................... TEMPERATURE (F) YESTERDAY MAXIMUM 89 325 PM 107 2005 94 -5 89 MINIMUM 68 1159 PM 42 1899 63 5 53 AVERAGE 79 78 1 71

JFK tied the record high of 94° today. RECORD EVENT REPORT NATIONAL WEATHER SERVICE NEW YORK, NY 0434 PM EDT SAT MAY 22 2021 ...RECORD HIGH TEMPERATURE SET AT KENNEDY NY... A RECORD HIGH TEMPERATURE OF 94 WAS SET AT KENNEDY NY TODAY. THIS TIES THE OLD RECORD OF 94 SET IN 1992.

The 93°at JFK is just under the 94° record high. 22 May 1:51 pm 92 52 26 WNW 16 10.00 FEW060,SCT190,BKN250 30.12 1020.4 30.13 93 67

Newark is close with a high of 94° so far today. 22 May 1:51 pm 93 54 27 NW 13 10.00 FEW140,FEW200,OVC250 30.11 1020.4 30.13 94 75

Easy to beat guidance with such dry conditions. Newark Liberty CLOUDY 92 52 25 NW13G21

91° at Newark with the warm downslope flow.

Higher population in Manhattan during those years than today. the Manhattan island population in 1900 was even larger (1.85 million persons in 1900) than today 1.54 million in 2000), due to turn-of-century immigration. So to the extent that population is an indicator of UHI strength, the relative 1900 UHI magnitude may be partial- ly understandable. http://www.theurbanclimatologist.com/uploads/4/4/2/5/44250401/gaffinetal2008nycuhiandtemptrends.pdf

Slowing AMOC and rapidly warming Gulf Of Maine have gone together with the anomalous ridging over New England and the Canadian Maritimes. So I guess that it’s no surprise that the seasonal models have a similar pattern this summer. It will be interesting to see if we can make it four summers in a row.

It’s been tough to bet against the greatest 500mb height anomalies setting up over New England since 2018. The stronger ridging to our NE has allowed for higher dewpoints and more onshore flow. If you want more westerly flow dry heat events like 2010 to 2013, then the best 500 mb anomalies need to be over the Great Lakes.

Second May in a row up at BTV with a top three warmest monthly maximum temperature. RECORD REPORT NATIONAL WEATHER SERVICE BURLINGTON VT 135 AM EDT FRI MAY 21 2021 ...RECORD HIGH TEMPERATURE SET AT BURLINGTON VT... A RECORD HIGH TEMPERATURE OF 92 WAS SET AT BURLINGTON VT YESTERDAY. THIS BREAKS THE OLD RECORD OF 91 SET IN 1975. Time Series Summary for Burlington Area, VT (ThreadEx) - Month of May Click column heading to sort ascending, click again to sort descending. Rank Year Highest Max Temperature Missing Count 1 2020 95 0 2 2017 93 0 - 1977 93 0 3 2021 92 11 - 2010 92 0 - 1987 92 0 - 1979 92 0 - 1978 92 0 - 1929 92 0 - 1911 92 0

Detroit was very close to the all-time May 500 mb height record this morning. Had we seen this anomalous a ridge during the summer, it would probably mean temperatures approaching or exceeding 100° In the Northeast. So it will be interesting to see if Newark can sneak in at least 95° max this month.

While specific rainfall forecasts past 5 days can be low skill, the Euro has a chance of rain on Memorial Day weekend. Every Memorial Day weekend for the last 5 years had measurable rainfall one out of the three days. We just missed a deluge in 2015 with 3.73 on Tuesday May 31st at Newark. Newark Memorial Day bolded 5-25-20…..5-23….0.79 5-27-19……5-26…0.20 5-28-18…..5-27….0.87 5-29-17…..5-29…..0.14 5-30-16……5-30…..1.57…….our last very dry spring Tuesday 5-31-15……3.73

If the long range guidance is correct, then the humidity will probably increase as we head into June. So this is when we could start to see better chances for rain again. The record breaking ridge just to our west is acting as a block. EPS lifts the ridge axis north to near the Canadian Maritimes to start June. This is where the ridge axis was for the last 3 summers with the warm and moist onshore flow. So it will be interesting to see if we can make it 4 in a row. EPS May 31- June 7 forecast

This was the lowest relative humidity 90° day at Newark in May since 2016. Came in with a relative humidity of 19% at 4pm. Matches up with this being the driest spring at Newark since 2016. Newark Liberty MOSUNNY 90 43 19 5-26-16…..91/43/19% 5-25-16…..90/39/17% Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Mar through May Click column heading to sort ascending, click again to sort descending. Rank Year Total Precipitation Missing Count 1 1935 4.54 0 2 2016 6.35 0 3 1941 6.50 0 4 1965 6.64 0 5 1995 6.81 0 6 2021 6.95 13 7 1985 6.99 0 8 1963 7.19 0 9 1959 7.61 0 10 1938 7.68 0 11 1981 8.13 0 12 2006 8.19 0 13 1962 8.25 0 14 1992 8.29 0 - 1971 8.29 0 15 1964 8.35 0