bluewave

The 12z guidance has moved to one of the most amplified backdoor patterns in recent years during the spring for the weekend.

Yeah, the record dewpoints and heat indices are much higher now than during the dry heat of the dust bowl. https://www.weather.gov/fgf/Top_Ten_of_the_2010s Throughout the afternoon of July 19th, 2011, temperatures across much of the Northern Plains region climbed above the 90F mark. With soils saturated from several days of widespread rain, and with area crops in full growth habit, the evapotranspiration rates were at their peaks. Dewpoint temperatures surged above the 80F mark from southern Minnesota, throughout the Red River Basin of the Dakotas and western Minnesota, into and across southern Manitoba. The 88F dewpoint reading in Moorhead MN set a new all-time statewide record for Minnesota, and the resultant Heat Index of 134F marked Moorhead as one of the hottest places on earth on that particular day!

All-time heaviest April snowstorm on record for BGM. So BGM continues the theme of historic snowfall since March 2017. RECORD EVENT REPORT NATIONAL WEATHER SERVICE BINGHAMTON, NY 1115 AM EDT TUE APR 19 2022 ...SNOWFALL RECORDS SET AT BINGHAMTON NY... THE 2 DAY SNOWFALL AS OF 1000 AM IS 14.2 INCHES AT THE GREATER BINGHAMTON AIRPORT IN THE TOWN OF MAINE, NY. THIS BREAKS THE ALL TIME APRIL RECORD FOR 2 DAY SNOWFALL. THE OLD RECORD WAS 13.6 INCHES SET APRIL 15 TO APRIL 16 2007. THE ONE DAY SNOWFALL SINCE MIDNIGHT LOCAL STANDARD TIME FOR TODAY IS 11.0 INCHES AS OF 1000 AM. THIS BREAKS THE RECORD SNOWFALL FOR APRIL 19 OF 6.9 INCHES SET IN 1983. THIS IS ALSO THE LATEST DATE FOR ONE DAY SNOWFALL OF AT LEAST 11.0 INCHES ON RECORD. RECORD EVENT REPORT...UPDATED NATIONAL WEATHER SERVICE BINGHAMTON, NY 235 PM EST THU DEC 17 2020 ...SNOWFALL RECORDS SET AT BINGHAMTON NY... THE 2 DAY SNOWFALL AS OF 1 PM IS 40.0" AT THE GREATER BINGHAMTON AIRPORT IN THE TOWN OF MAINE, NY. THIS BREAKS THE ALL TIME RECORD FOR 2 DAY SNOWFALL. THE OLD RECORD WAS 35.3" SET MARCH 14 TO 15, 2017. THE ONE DAY SNOWFALL FROM TODAY IS NOW 26.4" AS OF 1 PM. THIS IS THE SECOND GREATEST SNOWFALL FOR ANY CALENDAR DAY. THE GREATEST ONE DAY SNOWFALL IS 31.2" ON MARCH 14TH, 2017. THE SNOW HAS ENDED AND THE TOTALS ARE NOT EXPECTED TO CHANGE. ...SNOW DEPTH RECORD SET AT BINGHAMTON NY... THE SNOW DEPTH THIS MORNING AT 7 AM WAS 39 INCHES. THE OLD RECORD WAS 35 INCHES ON MARCH 15 1993 AFTER A BLIZZARD. RECORDS HERE AT THE GREATER BINGHAMTON AIRPORT GO BACK TO 1951. RECORD EVENT REPORT NATIONAL WEATHER SERVICE BINGHAMTON NY 715 AM EDT WED MAR 15 2017 ...ALL TIME 24 HOUR RECORD SNOWFALL SET AT BINGHAMTON NY... A 24 HOUR RECORD SNOWFALL OCCURRED AT THE GREATER BINGHAMTON AIRPORT FROM MARCH 14TH TO MARCH 15TH. A TOTAL OF 31.3 INCHES OF SNOW FELL BETWEEN 3 AM ON THE 14TH TO 1 AM ON THE 15TH. THIS BREAKS THE PREVIOUS 24 HOUR SNOWFALL RECORD OF 23 INCHES SET IN FEBRUARY 1961.

Looks like the 5th latest freeze date following the 5th earliest 71° at the airport since 1940. Frost/Freeze Summary for PHILADELPHIA INTL AP, PA Each section contains date and year of occurrence, value on that date. Click column heading to sort ascending, click again to sort descending. Year Last Value First Value Season Length 1966 05-11 (1966) 28 10-28 (1966) 32 169 1988 04-22 (1988) 32 10-13 (1988) 32 173 1956 04-21 (1956) 32 11-10 (1956) 30 202 1983 04-20 (1983) 32 10-30 (1983) 32 192 2022 04-18 (2022) 32 11-03 (1980) 31 199 First/Last Summary for PHILADELPHIA INTL AP, PA Each section contains date and year of occurrence, value on that date. Click column heading to sort ascending, click again to sort descending. Year First Value Last Value Difference 1950 01-06 (1950) 71 11-09 (1950) 73 306 2007 01-06 (2007) 73 11-22 (2007) 71 319 2002 01-29 (2002) 72 11-10 (2002) 72 284 1949 02-15 (1949) 74 11-11 (1949) 74 268 1954 02-15 (1954) 72 10-27 (1954) 71 253 2018 02-20 (2018) 72 11-02 (2018) 72 254 2017 02-23 (2017) 73 11-03 (2017) 73 252 2022 02-23 (2022) 71 - - -

Yeah, many places east of NYC are yet to make it higher than the low 70s so far.This looks like a rare March and April when the warmest temperatures occur before the 15h of both months. Warmest temperatures since March 1st across the area BDR…71 ISP…..73 JFK….72 LGA….74 NYC…79 EWR…88

Yeah, the dust bowl was a local event greatly magnified by human degradation of the land cover in the Plains. The rest of the world was much cooler during that era. The farming practices today are the opposite creating a localized zone with less summer warming relative to the rest of the US and world. https://www.nature.com/articles/s41467-020-16676-w The severe drought of the 1930s Dust Bowl decade coincided with record-breaking summer heatwaves that contributed to the socio-economic and ecological disaster over North America’s Great Plains. It remains unresolved to what extent these exceptional heatwaves, hotter than in historically forced coupled climate model simulations, were forced by sea surface temperatures (SSTs) and exacerbated through human-induced deterioration of land cover. Here we show, using an atmospheric-only model, that anomalously warm North Atlantic SSTs enhance heatwave activity through an association with drier spring conditions resulting from weaker moisture transport. Model devegetation simulations, that represent the wide-spread exposure of bare soil in the 1930s, suggest human activity fueled stronger and more frequent heatwaves through greater evaporative drying in the warmer months. This study highlights the potential for the amplification of naturally occurring extreme events like droughts by vegetation feedbacks to create more extreme heatwaves in a warmer world. https://www.science.org/content/article/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.

Spring backdoor pattern setting up from the weekend into next week. Warmest temperatures to our west with the front stalled out nearby So a battle of the SE Ridge and the -AO block. The -AO should finally win out later in April forcing the front further south.

Yeah, Long Island has done better than State College with snowfall since 2009. Dramatic reversal from the late 70s to early 90s. Much better benchmark snowstorm tracks now. Monthly Total Snowfall for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Year Oct Nov Dec Jan Feb Mar Apr May Season Mean 0.0 0.6 5.8 15.0 11.4 6.9 0.4 T 40.1 2021-2022 0.0 T 0.3 31.8 3.3 1.6 0.0 M 37.0 2020-2021 T 0.0 7.5 1.1 24.9 T T 0.0 33.5 2019-2020 0.0 0.1 4.2 2.5 0.0 T T T 6.8 2018-2019 0.0 4.3 T 0.9 3.5 4.1 T 0.0 12.8 2017-2018 0.0 T 6.0 22.0 1.4 31.9 4.6 0.0 65.9 2016-2017 T T 3.2 14.0 14.7 7.4 T 0.0 39.3 2015-2016 0.0 0.0 T 24.8 13.2 3.2 0.2 0.0 41.4 2014-2015 0.0 T 0.4 30.2 13.4 19.7 0.0 0.0 63.7 2013-2014 0.0 0.3 8.1 25.2 24.5 5.4 0.2 0.0 63.7 2012-2013 0.0 4.2 0.6 3.3 31.4 7.4 0.0 0.0 46.9 2011-2012 0.3 0.0 T 3.8 0.6 T 0.0 0.0 4.7 2010-2011 0.0 T 14.9 34.4 3.9 2.1 T 0.0 55.3 2009-2010 0.0 0.0 25.3 6.4 21.7 0.4 0.0 0.0 53.8 2008-2009 0.0 T 10.4 8.9 3.3 13.6 T 0.0 36.2 Monthly Total Snowfall for STATE COLLEGE, PA Click column heading to sort ascending, click again to sort descending. Year Oct Nov Dec Jan Feb Mar Apr May Season Mean 0.6 2.1 6.0 9.7 11.6 4.8 0.6 T 35.4 2021-2022 0.0 0.8 2.1 13.1 2.5 7.8 T M 26.3 2020-2021 0.0 T 16.3 4.2 25.2 T T T 45.7 2019-2020 0.0 2.0 2.3 5.3 2.0 0.9 0.7 T 13.2 2018-2019 T 11.7 0.2 11.6 11.7 4.9 T 0.0 40.1 2017-2018 0.0 0.3 6.6 5.0 9.7 6.9 5.6 0.0 34.1 2016-2017 T 0.5 6.5 5.0 9.5 16.3 T 0.0 37.8 2015-2016 T T T 9.9 6.4 0.2 1.4 T 17.9 2014-2015 0.0 5.2 2.5 21.3 14.7 7.8 0.5 0.0 52.0 2013-2014 T 4.0 11.1 10.0 26.7 T T 0.0 51.8 2012-2013 0.0 1.0 13.9 8.6 9.8 10.3 T 0.0 43.6 2011-2012 3.0 T 1.5 9.2 5.3 T T 0.0 19.0 2010-2011 T T 3.2 14.2 9.9 11.1 T 0.0 38.4 2009-2010 4.9 T 14.0 3.9 25.5 0.8 T T 49.1 2008-2009 0.2 3.9 4.0 14.3 3.9 T T 0.0 26.3 Monthly Total Snowfall for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Year Oct Nov Dec Jan Feb Mar Apr May Season Mean T 0.8 2.8 7.2 7.1 3.9 1.3 T 23.0 1978-1979 0.0 4.0 T 6.9 17.2 T T 0.0 28.1 1979-1980 T 0.0 1.5 4.0 1.5 2.0 0.0 0.0 9.0 1980-1981 0.0 T 0.5 13.2 T 7.1 0.0 0.0 20.8 1981-1982 0.0 0.0 1.0 18.1 0.3 T 16.0 0.0 35.4 1982-1983 0.0 0.0 3.2 1.5 26.1 T 1.1 0.0 31.9 1983-1984 0.0 T 2.6 11.9 T 13.0 0.0 0.0 27.5 1984-1985 0.0 T 4.7 13.5 8.7 T T 0.0 26.9 1985-1986 0.0 T 2.1 2.6 10.4 0.1 T 0.0 15.2 1986-1987 0.0 T 3.4 8.8 8.6 1.7 0.0 0.0 22.5 1987-1988 0.0 1.1 4.2 10.7 0.1 3.4 0.0 0.0 19.5 1988-1989 0.0 0.0 10.4 4.4 1.2 3.0 T 0.0 19.0 1989-1990 0.0 7.6 0.2 2.0 2.0 4.2 3.0 0.0 19.0 1990-1991 0.0 0.0 4.0 3.6 4.3 1.9 0.0 T 13.8 1991-1992 0.0 0.0 2.0 2.3 1.5 7.6 T 0.0 13.4 1992-1993 0.0 0.0 2.1 2.3 10.9 13.3 0.0 0.0 28.6 1993-1994 0.0 T 3.2 8.8 20.0 5.0 0.0 T 37.0 Monthly Total Snowfall for STATE COLLEGE, PA Click column heading to sort ascending, click again to sort descending. Year Oct Nov Dec Jan Feb Mar Apr May Season Mean T 2.2 6.5 12.4 10.9 11.9 1.8 T 45.7 1978-1979 T 2.1 6.8 10.5 19.7 0.8 T 0.0 39.9 1979-1980 T T 1.2 4.3 6.2 6.2 T 0.0 17.9 1980-1981 T 8.9 4.7 8.2 9.4 7.6 T 0.0 38.8 1981-1982 T 0.2 7.9 17.8 17.5 15.2 10.5 0.0 69.1 1982-1983 T T 1.8 6.7 10.9 3.2 T 0.0 22.6 1983-1984 0.0 3.1 7.4 12.8 2.7 24.2 T 0.0 50.2 1984-1985 0.0 0.4 3.3 11.7 10.7 0.8 4.7 0.0 31.6 1985-1986 0.0 T 9.6 11.7 19.9 1.0 0.1 0.0 42.3 1986-1987 0.0 3.0 0.8 35.1 5.8 5.7 1.9 0.0 52.3 1987-1988 T 7.8 8.2 9.9 7.5 5.4 0.2 0.0 39.0 1988-1989 T 0.1 2.5 7.8 1.6 11.6 0.1 T 23.7 1989-1990 T 3.0 12.2 13.5 3.4 3.7 5.0 T 40.8 1990-1991 T 0.1 10.9 7.9 2.7 12.3 0.5 0.0 34.4 1991-1992 0.0 2.6 0.7 4.9 2.3 15.6 0.8 0.0 26.9 1992-1993 T T 19.9 2.3 23.3 42.4 4.6 0.0 92.5 1993-1994 T 4.3 5.6 33.6 30.5 35.3 T 0.0 109.3

Friday may be the best chance for NYC and Newark to make a run on 70° for a while. The SE Ridge duels with the -AO block over the next week. So backdoor cold fronts will come into play. Very sharp gradient for us over the weekend. The area around NYC could stay in the 60s with 70s and 80s to the west on Sunday.The EPS has an unusually strong block from Greenland to Alaska from late April into early May. This will favor a trough of low pressure in the Northeast. There could be some late season freezes for the interior parts of the region. Apr 18-25 Apr 25-May 2

You know it must be the spring when these -AO forecasts correct stronger over time. New run Old run

April -AO blocking since 2004 has usually continued into May.

Our big temperature swings pattern continues. Newark dropped 50° degrees since last Thursday. Upper 80s to upper 30s is one of the greatest 88 hour temperature drops in Newark during April. It would be a little higher if off hour highs and lows were included. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=169&network=NJ_ASOS&zstation=EWR&hours=88&month=apr&dir=cool&_r=t&dpi=100&_fmt=png

Last summer the warmest part of NYC was in Central Queens just south of LGA. The 6-30-21 high at LGA was 100° and 102° at Corona. So that section of Queens was comparable to the area around Newark.The new micronet snapshot from early afternoon illustrated what was happening. There was a local convergence zone just north of the sea breeze front. The warmth probably was enhanced by some local downsloping off the higher moraine.

This is a much warmer storm for the coast than that one since we will have a +AO spike tomorrow. So the storm is going hug the coast instead of taking a BM track. But the higher elevations will get a heavy wet snow. The late March strat warming really primed the atmosphere for blocking with the near record weak SPV. This phasing storm Monday night will really pump the -AO block. Probably the most -AO of the year near -2. I think the 88° high at Newark on the 14th will stand as the warmest of the month. The late month blocking will probably favor an active backdoor pattern.

Looks like a tucked in storm track for Monday night. The low tracks right up the Jersey Shore into CT. Wind gusts near the coast may be in the 50-60 mph range. Rainfall generally 0.75 to 1.50 with locally higher amounts where the best elevated convection trains.

Looks like an impressive late season heavy rain and high wind event near the coast.

A recent study on the NYC UHI effect found that high rise buildings cast shadows which have a local cooling effect. So more high rise development doesn’t necessarily lead to increased UHI. It’s industrial use and low rise densely packed residential housing that has the greatest UHI. https://www.mdpi.com/2072-4292/13/19/3797/htm Our study shows that the trees and shadows cast by high-rise buildings and their variability have a cooling effect. In contrast, more impervious surfaces show a heating effect even in the presence of highly reflective bright surfaces. The census tract with industrial and manufacturing areas and multi-family walk-up buildings as dominant land use categories correspond to the highest mean surface temperature. Buildings with lower heights (fewer floors) and less height variability are associated with higher surface temperature. Although the building density is the highest in Manhattan (the central business district), many tall buildings with variable heights have shown cooling effects. Staten Island has the lowest mean surface temperature amongst all boroughs of New York City, where the number of trees is more. The Bronx has the highest mean surface temperature and constitutes moderate building density, height, and height variability. The finding from this study has an important implication for urban heat island modeling since recent surface temperature image reveals similar hotspot locations as observed 20 years ago. The results show the positive effects of trees and building shadows in reducing urban heat. It could help prioritize the areas to mitigate the UHI effect and reduce associated environmental and health-related costs, including sustainable urban planning.

There are a few reasons. UHI has been around for a long time and isn’t a recent phenomenon in NYC. The UHI effect in Manhattan became well established by 1890 to 1910. Queens saw a great expansion beginning in the 1930s and 1940s. JFK is right on the cooler South Shore so has cooling sea breezes that LGA doesn’t get. The trees are artificially cooling the NYC ASOS. JFK is our largest airport at 4930 acres. It’s the 6th largest in the world. So there can be a temperature range there by just driving from one part of the airport to another. I am not sure if the weather equipment moved when the ASOS was put in during the 1990s. It looks like the JFK equipment got moved to a cooler part of the airport. It’s our only station to have steady temperatures between the official 1981-2010 and 1991-2020 climate normals periods. All the other stations show an impressive increase in temperatures except JFK. Difference between 1991-2020 and 1981-2010 climate normals seasonal average temperatures EWR DJF…….+1.1 MAM….+0.4 JJA…...+0.5 SON…..+0.7 NYC DJF…....+1.1 MAM….+0.6 JJA…….+0.8 SON……+0.9 LGA DJF…….+1.4 MAM…..+1.0 JJA…….+1.5 SON……+1.3 JFK DJF……+0.1 MAM….-0.4 JJA……+0.1 SON….+0.3 HPN DJF….+1.4 MAM…+1.1 JJA…..+1.0 SON….+1.2 ISP DJF……+1.1 MAM..+0.7 JJA….+0.9 SON….+1.1 BDR DJF…..+1.2 MAM…+0.8 JJA……+1.2 SON…..+1.1

The blocking has been more impressive during the spring than the winter since the super El Niño.

The urbanization around LGA hasn’t changed since the 1980s. So any warming of the minimums since the 1980s is a result of the warming climate. POU and BDR have had more impressive minimum temperature rises during the summer than LGA. LGA max…..+2.3 min……+2.8 BDR max….+2.1 min…..+3.3 POU max…..+2.4 min…...+3.0

The ASOS in the 1990s replaced the previous automated systems of the 1970s and 1980s. So automation is nothing new . I found a fox weather story done back in January about the Central Park weather station at Belvedere Castle. You can see how the trees grew over the site in the 1990s. https://www.foxweather.com/watch/play-568120883000757 All the stations except Central Park are accurate since NYC is the only station with obstructions too close to the equipment. Some stations have had faster minimum rises like LGA, HPN, BDR, and POU. So those accurately reflect local changes. Warming is an uneven process with the minimums rising faster in some spots and others showing more maximum rises. This can also change from season to season.

Strongest -AO drop of the year so far coming up. The whole area would have had above normal snowfall if this block occurred from February into March.

This may be among the most variable spring temperature patterns that we have seen since March 1st. The SE Ridge has been dueling with the -AO block. So our next cool down is on track for Monday morning with a late season freeze for the usually colder spots. Then we warm up again back to the 70s by later next week. This is followed by another backdoor cool down. Then we may get another chance for 80s around day 8-10 as the SE Ridge flexes. Then more blocking near the end of April with another step down in temperatures. Big temperature swings for the rest of the month

This continuing La Niña background state is on steroids. So it favors another very active hurricane season. Then maybe a rare 3rd year La Niña for next winter. Enough preamble—what’s the Walker circulation doing right now? I thought you’d never ask. It’s really feeling its oats these days, as several different atmospheric measurements tell us. First, let’s talk Equatorial Southern Oscillation, an index that measures the relative sea level pressure in the far western Pacific vs. that in the eastern Pacific. When the EQSOI is positive, it indicates lower-than-average pressure over the west (more rain and clouds) and higher-than-average pressure over the east (less rain and clouds), i.e., evidence of a stronger Walker circulation. In March, the EQSOI measured 1.4, the 6th strongest since 1950. As I mentioned above, stronger trade winds are key to the La Niña feedback between the ocean and atmosphere. The trade winds were enhanced through March, and remain stronger than average into mid-April. You want a number, you say? Okay! There’s an index that measures the near-surface winds in the central Pacific region of 5°N–5°S, 175°W–140°W; it was 4.3 meters per second (9.6 miles per hour) faster than average in March. This is the strongest March value on record, but there’s a catch—this record only goes back to 1979. One more index! The central Pacific was much less cloudy and rainy than average in March. We monitor cloudiness via satellite, by looking at how much radiation is leaving the Earth’s surface and reaching the satellites. Less radiation making it to the satellite means more clouds are blocking the path. The index that measures outgoing radiation (and therefore cloudiness), the CPOLR, tells us that this March featured the least amount of clouds for any March on record over the central Pacific. We’re number 1! Again, though, like the winds, this record only goes back to 1979, when the satellite measurement era began. So, a grain of salt with your records. One last measurement today—let’s look under the surface of the tropical Pacific Ocean. The amount of cooler-than-average water under the surface increased in March. This cooler subsurface water provides a supply of cooler water to the surface, contributing to ENSO forecasters’ prediction that La Niña will remain into the summer. Index-wise, last month the water under the surface was the 9th coolest March since 1979.

Worcester only needs 0.5 of snow to avoid a rare defeat by Boston. Time Series Summary for Worcester Area, MA (ThreadEx) Click column heading to sort ascending, click again to sort descending. Ending Date Total Snowfall Oct 1 to May 31 Boston 2022-05-31 53.6 54.0 2021-05-31 76.8 38.6 2020-05-31 44.9 15.8 2019-05-31 51.4 27.4 2018-05-31 96.1 59.9 2017-05-31 78.3 47.6 2016-05-31 47.2 36.1 2015-05-31 119.7 110.6 2014-05-31 85.2 58.9 2013-05-31 108.9 63.4 2012-05-31 39.7 9.3 2011-05-31 92.6 81.0 2010-05-31 64.6 35.7