bluewave

Brian Brettschneider has a great series of posts on this. But a recent study finds that this local irrigation effect will be overcome with continued global warming. https://news.wisc.edu/irrigated-farming-in-wisconsins-central-sands-cools-the-regions-climate/ While the cooling effect of irrigation mitigates global climate change on the regional scale, climate models suggest that regional warming attributed to the global trend will eventually overcome the magnitude of mitigation offered by irrigated agriculture. Farmers, who are partially buffered for now from more extreme heat, would quickly face increasing stress in that scenario. “Farmers in irrigated regions may experience more abrupt temperature increases that will cause them to have to adapt more quickly than other groups who are already coping with a warming climate,” says Kucharik. “It’s that timeframe in which people have time to adapt that concerns me.” The current study is the first to definitively link irrigation in the Midwest U.S. to an altered regional climate. These results could improve weather and climate forecasts, help farmers plan better, and, the researchers hope, better prepare agricultural areas to deal with a warming climate when the irrigation effect is washed out. https://mobile.twitter.com/Climatologist49/status/1139633305958014976 Map animation showing the 100-year change in monthly temperatures using NCEI county-level temperature data. In the summer months, the central U.S. is the only region on Earth showing a notable temperature decline. Likely related to irrigation. https://mobile.twitter.com/Climatologist49/status/1140048246477168640 https://mobile.twitter.com/Climatologist49/status/1140059426847461376 https://mobile.twitter.com/Climatologist49/status/1140057959973572609 https://mobile.twitter.com/Climatologist49/status/1140059253857640448 https://mobile.twitter.com/Climatologist49/status/1126293596909367301

From Climate Signals and Brian Brettschneider: https://mobile.twitter.com/ClimateSignals/status/1156929127414403074 In a stable climate, record high and low temps are about even. Globally, in July 2019, there were 132 all-time high temp records and only 2 all-time lows. Human-caused warming is driving this imbalance. https://mobile.twitter.com/Climatologist49/status/1158129812738699265 July 2019 temperatures mapped as percentile of all July temperatures (min 50 years). 134 stations with warmest July. 2 stations with coldest July. Spatial average of 71st percentile good for either 1st or 2nd warmest July on record globally.

We are entering the big decline week when 2012 pulled ahead of all other years. This was during the period of the Great Arctic Cyclone. NSIDC extent Date....2012......2019....2019 difference 8-4......5.990.... 5.762.....+228k lead 8-5......5.768 8-6......5.632 8-7......5.467 8-8......5.256 8-9......5.088 8-10....5.118 8-11....5.021

While the high temperatures have stepped down from the steamy July levels, the minimum temperatures are still staying up. NYC is currently at the 6th longest streak of 67 degrees or higher. Islip has the 2nd longest 64 degrees or warmer streak. A continuation of the less warm is the new cool theme. Number of Consecutive Days Min Temperature >= 67 for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Run Length Ending Date 1 46 2005-08-24 2 44 1988-08-18 3 42 2015-08-27 4 36 1939-08-28 5 35 1938-08-11 6 34 2019-08-04 Number of Consecutive Days Min Temperature >= 64 for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Rank Run Length Ending Date 1 46 1988-08-18 2 41 2019-08-04 3 33 1980-08-16 4 32 2013-07-24 5 31 2006-08-08

Brief moderate shower here with the sun out. Just enough to wet the ground. Good thing for modern sprinkler systems with very little rain over the last 11 days.

3 top 5 warmest Augusts in 4 years was a very impressive streak. It appears we are backing off a bit from the extreme August heat of recent years. Time Series Summary for LA GUARDIA AP, NY - Month of Aug Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Missing Count 1 2016 81.6 0 2 2018 81.0 0 3 2005 80.9 0 4 2001 79.8 0 5 2015 79.3 0

NCEP/NCAR Reanalysis monthly means. https://www.esrl.noaa.gov/psd/data/timeseries/

May through July set new Arctic records for warmth, surface pressure, and 500 mb heights.

The ridge that dominated the Northeast with record heat in July will take a break for a while.

Surface conditions have quickly dried out along the Long Island South Shore since July 24th. Most of the grass and vegetation not regularly watered turned brown. Best recent sea breeze front convection has been favoring the North Shore. The last 10 period has been the 3rd driest on record at Islip. Time Series Summary for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Total Precipitation Jul 24 to Aug 2 Missing Count 1 2006-08-02 0.02 0 2 1972-08-02 0.04 0 3 2019-08-02 0.05 0 4 2005-08-02 0.07 0 5 1999-08-02 0.13 0

It looks like it will make it difficult for the August temperature departure to beat July. Our warmer summers since 2015 all had a greater August temperature departure than July. 2015 LGA....JUL...+1.8.....AUG...+3.0 2016 LGA....JUL...+3.7....AUG....+5.3 2018 LGA....JUL...+2.4....AUG....+4.7 2019 LGA....JUL...+4.1 Plenty of unknowns concerning next winter at this time. Will the raging Pacific jet relax? Will the record summer -NAO extend into winter? What will happen with ENSO? Will the amped up MJO continue for another winter? How will the extreme Arctic summer warmth and low sea ice impact the fall and winter circulation?

The duration of that eventual Northeast trough may come down to the MJO. The MJO is finally becoming active again. Phase 4 in August favors a trough over the region. https://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ecmm.shtml https://ds.data.jma.go.jp/tcc/tcc/products/clisys/mjo/composite.html

Large -299k drop in NSIDC extent over the last 2 days. This puts 2019 +259 k ahead of 2012 as of August 2nd. 2019 needs to maintain an average daily decline rate of 97k over the next 9 days to hold even with 2012 by the 11th. NSIDC extent 8-2-19.....5.893 8-2-12.....6.152 8-11-12....5.021

The epic Pacific firehose jet just won’t let up. This time it was nearly forced up to the Arctic circle with record rains in Nome,Alaska. https://mobile.twitter.com/AlaskaWx/status/1157502080392712192 There it is: Nome, Alaska, with one of the longest climate records in the state (since 1907) sets all-time 24 hour precipitation record: 10pm AKDT Thursday to 8pm Friday rainfall 2.43" (61.7mm) breaks previous record 2.38" (60.5mm) Aug 8-9, 1956. https://mobile.twitter.com/AlaskaWx/status/1157352074373259264 Remember the atmospheric river forecast from a few days ago? It's here: Nome received 2.09" (53.1mm) in 12-hours between 10pm Thursday & 10am Friday. The greatest 24-hour rainfall at Nome is 2.38" (60.5mm) Aug 8-9, 1956.

Zack Labe is reporting that July set the new lowest NSIDC average extent for the month. The only months not to set a new record low since 2016 so far have been ASO. 9 new monthly records in 3 years shows how much the Arctic has warmed. https://mobile.twitter.com/ZLabe/status/1156938182832693249 New Record* -- 2019 averaged the lowest #Arctic sea extent in the satellite-era for the month of July. It was 1,880,000 km² below the 1981-2010 average. Data from @NSIDC https://mobile.twitter.com/ZLabe/status/1157122835409596416 Updated record low #Arctic sea ice extent months - @NSIDC data (satellite-era from 1978/1979) -------------- 2018 : January 2018 : February 2017 : March 2019 : April 2016 : May 2016 : June 2019 : July 2012 : August 2012 : September 2012 : October 2016 : November 2016 : December

At least for the time being, the harshest melting conditions are focused over Greenland. NSIDC had a very small drop yesterday of 44k down to 6.192. It maintains a narrow lead over 2012 of 176k which was at 6.368. August 1-11, 2012 experienced the record breaking decline down to 5.021. This year would require an average daily decline rate of 106k to keep pace by August 11th.

July was another top 10 warmest around the area. 7...2019....EWR...7.....NYC..10...LGA...3....JFK....4....BDR...3.....ISP...2

NSIDC extent is only 163k above 2012 as of 7-30. 7-30-19...6.237 7-30-12....6400 2019 needs to increase the decline rate next 10 days in order not to fall below 2012 on August 9th. The average daily decline rate last 10 days was 81k. This year would need an average 115k daily to keep up with 2012 over the next 10 days. 8-9-12.....5.088 9-16-12...3.340....lowest daily September minimum on record The area is tracking a bit behind 2012 as of 7-30.

Discuss...

7-27-19 has a narrow lead of 214k over 7-27-12 for NSIDC extent. 2019 needs to maintain an average daily drop rate of 106k next 13 days in order not to fall behind 2012. This first 9 days of August was when 2012 experienced the record breaking decline. There was a 3 day interval with over 500k of losses during the deep Arctic storm. So it may be tough to catch up with 2012 later in the season if 2019 falls much behind next few weeks. We’ll see how it goes. 7-27-19...6.463 7-27-12...6.677 8-9-12.....5.088 9-16-12...3.340....lowest daily September minimum on record

It may also struggle under extreme blocking and dipole regimes like we are seeing this year. Its biggest miss or underestimation of melt from a June forecast was in 2015. July 2015 experienced the strongest blocking and dipole pattern during the 2013 to 2018 era. June 2015 CPOM forecast September average extent......5.10....Verification.......4.63 This was the most impressive piece of information from the statistical model that CPOM uses for their forecasts. The simulated melt pond fraction in June 2019 has been higher then in any June before.

12z Euro has record breaking 500mb heights and surface pressures over the CAB for this time of year.

Numerous 3.00+ amounts with Syosset near the top at 3.94. Syosset 3.94 856 AM 7/23 Co-Op Observer

Here’s a quote from Wipneus on the July 15th PIOMAS update: PIOMAS has updated the gridded thickness data to the 15th of this month. Volume calculated from this was 8.77 [1000km3]. That is the lowest for the day, with quite a margin.

The Arctic experienced a record May and June combination of warmth and high pressure. So we have been seeing steep declines this week even with more favorable conditions than the last few months.