bluewave

A split departure month around the area. NYC and LGA were closer to -1 and the others are near normal for April. New England was warmer than average. EWR…..+0.1 NYC…..-0.9 LGA……-1.3 JFK……+0.1 ISP……..+0.3

Relative humidity down to 9% at Newark with the dew point getting close to 0. This is the 2nd April in a row with the relative humidity dropping below 10%. Newark/Liberty MOSUNNY 63 3 9%

NE PA and NW NJ did much better with April rainfall than they did with seasonal snowfall. 4th wettest April Time Series Summary for WILKES-BARRE/SCRANTON INTERNATIONAL AIRPORT, PA - Month of Apr Click column heading to sort ascending, click again to sort descending. Rank Year Total Precipitation Missing Count 1 1983 9.56 0 2 1993 7.47 0 3 2011 6.51 0 4 2022 6.16 2

It was a top 5 wettest April west of NYC where the best training set up.

Yesterday was our driest day of the year with the relative humidity dropping to 10%. So quite a shift from the record rainfall around the area in recent weeks. The drier ending to April prevented parts of the area from recording another 10.00” month. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=157&network=NJ_ASOS&station=EWR&year=2022&var=min_rh&dir=below&thres=95&_r=t&dpi=100&_fmt=png Monthly Data for April 2022 for Upton NY NWS CWA Click column heading to sort ascending, click again to sort descending. State Name Station Type Total Precipitation NJ CHARLOTTEBURG RESERVOIR COOP 8.23 NJ WAYNE TWP 2.3 ESE CoCoRaHS 8.20 NJ LITTLE FALLS TWP 0.5 WNW CoCoRaHS 7.89 NJ GLEN ROCK 0.4 WNW CoCoRaHS 7.89 NY PORT JERVIS 2.9 ESE CoCoRaHS 7.79 NJ LITTLE FALLS TWP 0.2 NE CoCoRaHS 7.68 NJ BLOOMINGDALE 1.6 S CoCoRaHS 7.66 NY PORT JERVIS COOP 7.65 NJ HAWTHORNE 1.0 SSE CoCoRaHS 7.65 NY PINE BUSH 3.4 WSW CoCoRaHS 7.64

I started a new thread to discuss the May pattern.

Looks like an omega block pattern to start May. EPS May 2-9

Yeah, a monthly minimum this warm generally had much higher monthly average temperatures. Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of Apr Click column heading to sort ascending, click again to sort descending. Rank Year Lowest Min Temperature Average Temperature 1 2012 38 55.2 - 2010 38 57.9 2 2011 37 55.5 - 1998 37 53.9 3 2022 36 53.4 - 2017 36 57.2 - 1994 36 57.4

Yeah, the real warmth on that day was mostly limited to west of the Hudson due to the strong onshore flow influence. Monthly Data for April 2022 for Upton NY NWS CWA Click column heading to sort ascending, click again to sort descending. State Name Station Type Highest Max Temperature NJ NEWARK LIBERTY INTL AP WBAN 88 NJ TETERBORO AIRPORT WBAN 88 NJ CALDWELL ESSEX COUNTY AP WBAN 88 NJ HARRISON COOP 87 NY SHRUB OAK COOP 85 NY PORT JERVIS COOP 84 NJ CHARLOTTEBURG RESERVOIR COOP 83 NY MONTGOMERY ORANGE COUNTY AP WBAN 83 CT DANBURY MUNICIPAL AP WBAN 81 NY CARMEL 4N COOP 80 NY NY CITY CENTRAL PARK WBAN 79 NY CENTERPORT COOP 77 NY SYOSSET COOP 77 NY BAITING HOLLOW COOP 77 CT MERIDEN MARKHAM MUNICIPAL AP WBAN 77 CT OXFORD WATERBURY WBAN 76 NY RIVERHEAD RESEARCH FARM COOP 75 CT STAMFORD 5 N COOP 74 NY WESTCHESTER CO AP WBAN 74 CT NORWICH PUBLIC UTILITY PLANT COOP 74 NY FARMINGDALE REPUBLIC AP WBAN 73 NY ISLIP-LI MACARTHUR AP WBAN 73 NY JFK INTERNATIONAL AIRPORT WBAN 72 CT NEW HAVEN TWEED AP WBAN 72 NY UPTON COOP - NWSFO NEW YORK COOP 72 NY LAGUARDIA AIRPORT WBAN 71 CT IGOR I SIKORSKY MEMORIAL AIRPORT WBAN 71 NY SHIRLEY BROOKHAVEN AIRPORT WBAN 71 CT GROTON NEW LONDON AP WBAN 70 NY WESTHAMPTON GABRESKI AP WBAN 69 NY MONTAUK AIRPORT WBAN 65 NY ORIENT POINT STATE PARK COOP 65 NY BRIDGEHAMPTON COOP

Yeah, this month we had slightly cooler than average highs and warmer lows.

The low temperatures this morning came in warmer than models forecast. So the cooler high temperatures this month have kept the departures down. Several of our stations will finish near the top for warmest April lowest temperatures. One of the few times that cool spots like HPN didn’t drop below freezing in April. Time Series Summary for WESTCHESTER CO AP, NY - Month of Apr Click column heading to sort ascending, click again to sort descending. Rank Year Lowest Min Temperature Missing Count 1 2010 36 0 2 2017 33 0 - 1983 33 1 - 1953 33 0 3 2022 32 5 - 2006 32 0 - 2005 32 0 - 1999 32 6 - 1998 32 5 - 1988 32 1 - 1986 32 0 - 1960 32 1 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 Lowest Min Temperature Missing Count 1 1878 42 0 2 2010 40 0 3 2022 38 3 - 2012 38 0 Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of Apr Click column heading to sort ascending, click again to sort descending. Rank Year Lowest Min Temperature Missing Count 1 2012 38 0 - 2010 38 0 2 2011 37 0 - 1998 37 0 3 2022 36 3 - 2017 36 0 - 1994 36 0 Time Series Summary for ISLIP-LI MACARTHUR AP, NY - Month of Apr Click column heading to sort ascending, click again to sort descending. Rank Year Lowest Min Temperature Missing Count 1 2017 34 0 - 2010 34 0 - 1988 34 0 2 2022 33 3 - 1999 33 0 - 1983 33 0 3 2012 32 0 - 2011 32 0 - 1993 32 0 - 1991 32 0

Yeah, the record warm pool north of Australia continues to be a big story.

The general rule is we get more active Atlantic hurricane seasons with a La Niña and warm Atlantic SSTs. A -IOD serves to enhance the La Niña background state with stronger trade winds. The last strong summer -IOD was in 2016 and helped to shift the super El Niño to a 2 year La Niña. Causes and Predictability of the Negative Indian Ocean Dipole and Its Impact on La Niña During 2016 https://www.nature.com/articles/s41598-017-12674-z

A bit different from our last two strong summer -IOD events. The summer 2016 and 2010 -IOD patterns came at the start of those two year La Niña events. If the models are correct, then this could be the strongest -IOD between the 2nd and potentially 3rd year La Niña. But anything is possible with those record SSTs north of Australia. The trade winds in the Central Pacific have been at record levels for the early spring since 1979. https://www.climate.gov/news-features/blogs/enso/april-2022-la-niña-update-measuring 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.

It will be interesting to see if the models are correct about the near record summer -IOD.

Not much difference between the warmest temperatures in late February and April this year. Low 70s will be the max for both periods. We were also close in 2020. The most extreme was the 80° in late February 2018 and only 70 in late April. Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Ending Date Highest Max Temperature Feb 20 to Feb 28 Apr 20 to Apr 30 2022-02-28 70 72 +2 2021-02-28 54 89 +35 2020-02-29 62 68 +6 2019-02-28 52 78 +26 2018-02-28 80 70 -10 2017-02-28 74 86 +12 2016-02-29 64 83 +19 2015-02-28 42 78 +36 2014-02-28 54 76 +22 2013-02-28 51 71 +20 2012-02-29 60 74 +14 2011-02-28 61 85 +24 2010-02-28 50 81 +31

The latest EPS shifts the -AO block in late April to more of an omega block in early May. So a continuation of the generally cooler pattern. Could see above normal rainfall in early May with a strong Pacific Jet undercutting the block. Apr 25 to May 2 May 2 to May 9

Late April interior freeze this week as the cold that has been sitting over the Northern Tier shifts east.

The SPV was too strong this winter.

One of the few times that such a strong SE Ridge gets overpowered by the -NAO block.

Big backdoor gradient today with highs in the 60s around NYC and 80s to the south and west of the area.

We are on track for another top 5 coldest late April high temperature. This has been a common theme in recent years. Its the reverse of late February which has been top 5 warmest. So a continuation of the big temperature swings pattern. Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Ending Date Highest Max Temperature Apr 16 to Apr 30 Missing Count 1 2020-04-30 68 0 2 2018-04-30 70 0 - 1940-04-30 70 0 3 1988-04-30 71 0 - 1937-04-30 71 0 - 1931-04-30 71 0 4 1966-04-30 72 0 5 2022-04-30 73 8 - 1978-04-30 73 0 6 1998-04-30 74 0 - 1997-04-30 74 0 - 1950-04-30 74 0 Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Ending Date Highest Max Temperature Feb 16 to Feb 28 Missing Count 1 2018-02-28 80 0 2 2017-02-28 74 0 - 1997-02-28 74 0 - 1954-02-28 74 0 3 1985-02-28 73 0 4 2011-02-28 71 0 5 2022-02-28 70 0 - 1939-02-28 70 0

We were 2nd behind 2012 in 70° days by the start of astronomical spring. But have fallen back to 6th place with the 10th day of the year to reach 70° today. Last year finished in 1st place with 177 days. Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Ending Date Number of Days Max Temperature >= 70 Jan 1 to Mar 21 Missing Count 1 2012-03-21 6 0 2 2022-03-21 4 0 - 2020-03-21 4 0 - 1990-03-21 4 0 - 1946-03-21 4 0 - 1945-03-21 4 0 Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Ending Date Number of Days Max Temperature >= 70 Jan 1 to Apr 22 Missing Count 1 1945-04-22 19 0 2 2012-04-22 18 0 3 2010-04-22 13 0 - 1977-04-22 13 0 4 1976-04-22 12 0 - 1954-04-22 12 0 5 2016-04-22 11 0 - 2002-04-22 11 0 - 1987-04-22 11 0 - 1985-04-22 11 0 - 1946-04-22 11 0 6 1998-04-22 10 0 - 1981-04-22 10 0 2022-04-22 10 0 Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Jan through Dec Click column heading to sort ascending, click again to sort descending. Rank Year Number of Days Max Temperature >= 70 Missing Count 1 2021 177 0 2 2010 173 0 3 2015 171 0 - 1985 171 0 4 2007 170 0 5 1994 169 0 - 1946 169 0

The spring bloom was 2-3 weeks ahead of schedule in some spots before the late March hard freeze.

The concern is that the Western drought expands east to the Plains in the future resulting in lower crop yields and desertification. https://www.sciencedaily.com/releases/2020/10/201013124158.htm The first Dust Bowl In the 1930s, a drought blanketed the Great Plains, from Mexico to Canada. This wouldn't have been such a big deal except that in the 1920s Midwestern farmers had converted vast tracts of grassland into farmland using mechanical plows. When the crops failed in the drought the open areas of land that used to be covered by grass, which held soil tightly in place, were now bare dirt, vulnerable to wind erosion. "The result was massive dust storms that we associate with the Dust Bowl," Lambert says. "These dust storms removed nutrients from the soil, making it more difficult for crops to grow and more likely for wind erosion to occur." After years of drought, dust and hardship, rain finally began to fall again, bringing the Dust Bowl to a close. "But the damage was already done to the soil," Lambert says. "Some areas have still not fully recovered." Around the 2000s, the growth in demand for biofuels spurred renewed expansion of farmland to produce the needed crops. In an echo of the 1920s, this expansion replaced stable grasslands with vulnerable soil. Over five years, from 2006 to 2011, 2046 square miles (530,000 hectares) of grassland in five Midwestern states became farmland -- an area a little smaller than Delaware. At the same time, parts of the Great Plains experienced longer and more severe droughts in the 20th century. The future of drought in that region is, so far, uncertain, but the potential for a warmer, drier Great Plains has Lambert and co-author Gannet Hallar, associate professor of atmospheric sciences, bringing up the word "desertification" in relation to the potential future of the region. All together, the data cover years from 1988 to 2018. Dust, they found, is increasing in the atmosphere over the whole of the Great Plains by as much as 5% per year. "The amount of increase is really the story here," Hallar says. "That 5% a year over two decades, of course, is a hundred percent increase in dust loading. This is not a small signal to find." Correlating with crop timing The researchers further found correlations between dust in the atmosphere and crop timings. In Iowa, where soybeans have been a major expanding crop, increases in dust appeared in June and October -- planting and harvesting months, respectively, for soybeans. In the southern Great Plains states, where corn is a more dominant crop, dust increases appeared in March and October -- again correlating to corn planting and harvesting seasons. That was remarkable," Hallar says, "in the sense of how clear the signal was." Are we seeing the beginnings of the second Dust Bowl? "I think it's fair to say that what's happening with dust trends in the Midwest and the Great Plains is an indicator that the threat is real if crop land expansion continues to occur at this rate and drought risk does increase because of climate change," Lambert says. "Those would be the ingredients for another Dust Bowl." "This is an example of the need for the agricultural community in the U.S. to think about adapting and mitigating to a changing climate," Hallar says. "So if we become more arid we will need to think about the impacts of land degradation in that changed climate. What we did in the past isn't necessarily what we can do in the future."