donsutherland1

July 2020 was also Phoenix’s hottest month on record by 0.6 degrees.

The region saw its coolest readings since just after mid-June this morning. During the afternoon, the temperature rebounded into the lower and middle 80s. Another brief cool shot is possible near mid-week. Noticeably warmer weather could arrive for the weekend. Out west, extreme heat again prevailed in the Southwest. Select high temperatures included: Death Valley, CA: 126° (old record: 124°, 2001) Flagstaff: 88° (old record: 87°, 1992 and 2002) Kingman, AZ: 110° (old record: 109°, 1915) Lake Havasu City, AZ: 115° Las Vegas: 114° (old record: 111°, 1992) Mesa, AZ: 111° (old record: 102°, 2019) Needles, CA: 118° (old record: 115°, 1992 and 2011) Palm Springs, CA: 114° Phoenix: 115° (old record: 112°, 2011) Sacramento: 106° Stockton, CA: 107° (tied record set in 1967) Tucson, AZ: 107° (old record: 107°, 2013) Yuma, AZ: 111° Death Valley reached 125° or above for the fourth consecutive day. That surpassed the previous August record, which was set during August 11-13, 1933 and tied during August 6-8, 1998. Intense heat will likely continue in that region into the coming weekend although the most severe heat will fade after midweek. Phoenix has an implied 97% probability of having its warmest summer on record. Phoenix will likely finish with a summer mean temperature of 96.4° - 96.8°. The existing record is 95.1°, which was set in summer 2013 and tied in summer 2015. July 2020 was Phoenix's warmest month on record with a mean temperature of 98.9°. Since recordkeeping began in August 1895, two years saw both July and August rank among Phoenix's 20 warmest months on record: 2007 and 2019. It is all but certain that 2020 will become the third such case. The current predominantly warmer than normal pattern will likely persist through much of September, paving the way for a solidly warmer than normal summer and a warm start to fall throughout the region. Occasional short-lived cool shots remain possible. The ENSO Region 1+2 anomaly was -0.9°C and the Region 3.4 anomaly was -0.5°C for the week centered around August 12. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -1.17°C and the ENSO Region 3.4 anomaly has averaged -0.45°C. Neutral-cool conditions will likely into the start of autumn. During the autumn, La Niña conditions will likely develop. The SOI was +10.56. Today, the preliminary Arctic Oscillation (AO) figure was -1.377. On August 17, the MJO was in Phase 8 at an amplitude of 1.837 (RMM). The August 16-adjusted amplitude was 1.632. The MJO's recent passage through Phase 4 at an amplitude of 1.500 or above has been uncommon during the first half of August. During the 1981-2019 period only 1983 and 2019 saw the MJO move through Phase 4 with an amplitude of 1.500 or above during the first half of August. August 1983 had the longest such stretch. Both cases saw the second half of August average generally warmer than normal in the Middle Atlantic region. Both cases also featured a warmer than normal September. Last year, the MJO went through a very strong passage through Phase 1 during the closing days of May. About four weeks later, a warmer than normal pattern locked in and predominated through early autumn. This year, the MJO was in Phase 1 for 3 consecutive days with an amplitude of 1.500 or above during the June 1-3 period. Last year, the SOI fell to -42.04 on June 22 when the MJO was in Phase 6. This year, the SOI plunged below -46.68 on June 5, its lowest level in more than three years. The dramatic plunge in the SOI could be the proverbial spark that kicks off a sequence of events leading to the development of a sustained warmer than normal period. The cases that saw both the MJO and SOI thresholds satisfied generally saw 10-20 days where the temperature reached or exceeded 90° in New York City during the July 1-August 31 period. Since 1990, there have been 11 La Niña events, 6 of which followed an El Niño winter. 10/11 (91%) case saw warmer than normal September. All 6 following an El Niño winter were warmer than normal. September mean temperatures for New York City for those cases were: 11 cases: 69.9°; Subset of 6 cases: 70.8°; Entire 1990-2019 period: 69.0°. The September mean temperature for all La Niña and neutral-cool cases following an El Niño winter (1950-2019: n=13) was 69.9°. Overall, the evolution of ENSO, along with the observed ongoing monthly warming (1.6°/decade in NYC and 1.5°/decade in the Northeast Region during September 1990-2019), favors a warmer than normal September. Since 1950, there have been five cases where a La Niña developed during June-July-August or afterward following an El Niño winter. 4/5 (80%) of those cases saw a predominant EPO+/AO+ winter pattern. The most recent such case was 2016-17. 9/10 (90%) of the La Niña winters that followed an El Niño winter featured a predominantly positive EPO. Based on sensitivity analysis applied to the latest guidance, there is an implied 79% probability that New York City will have a warmer than normal August. August will likely finish with a mean temperature near 77.0°. Finally, on August 17, Arctic sea ice extent was 4.782 million square kilometers (JAXA). There is an implied 63% probability that Arctic sea ice extent will reach a minimum figure below 4.000 million square kilometers for the second consecutive year and third time on record. The highest 25% bound is 4.129 million square kilometers. The lowest 25% bound is 3.609 million square kilometers.

I tried to take it, but received the following message: This survey is now closed, but the Haz Simp team will still be accepting comments on the proposal via email ([email protected]) through August 21, 2020. Thank you for your interest!

Morning thoughts... It was another cool morning in parts of the region. At New York City, the temperature fell to 63 degrees, its coolest figure since June 17 when the temperature fell to 60 degrees. At Newark, the temperature fell to 63 degrees. The last time it was at least as cool there was on June 17 when the temperature dropped to 60 degrees. Under bright sunshine, temperatures will rebound to the lower and even middle 80s. After another short mid-week cool shot, noticeably warmer conditions will likely develop for the coming weekend. Out west, intense heat will again topple records in parts of California, Arizona and Nevada. Out in the eastern Atlantic, a new tropical depression could develop in coming days.

From this evening as a thunderstorm passed to the north of Larchmont. The Village received a downpour, but only a few drops fell right at the Long Island Sound.

The region saw its coolest readings since just after mid-June this morning. However, under sunshine, the temperature rebounded into the upper 70s and lower 80s. The day ended with scattered thunderstorms. Another brief cool shot is possible near mid-week before a more prolonged warming trend takes hold. Out west, extreme heat again prevailed in the Southwest. Select high temperatures included: Bishop, CA: 105° Blythe, CA: 117° (old record: 116°, 1950 and 1992) Death Valley, CA: 127° (old record: 125°, 1994) Flagstaff: 91° (old record: 88°, 2002) Kingman, AZ: 108° (old record: 106°, 2001) Lake Havasu City, AZ: 115° Las Vegas: 112° (old record: 111°, 1939) Mesa, AZ: 113° (old record: 106°, 2019) Needles, CA: 117° (tied record set in 1892) Palm Springs, CA: 114° Phoenix: 115° (old record: 114°, 2013) Sacramento: 105° Stockton, CA: 109° (old record: 106°, 1967) Tucson, AZ: 109° (old record: 108°, 2013) Yuma, AZ: 114° (tied record set in 1892 and tied in 1953 and 1992) Death Valley reached 125° or above for the third consecutive day. That ties the August record, which was set during August 11-13, 1933 and tied during August 6-8, 1998. Intense heat will likely continue in that region into the coming weekend although the most severe heat will fade after midweek. Phoenix has an implied 96% probability of having its warmest summer on record. Phoenix will likely finish with a summer mean temperature of 96.3° - 96.7°. The existing record is 95.1°, which was set in summer 2013 and tied in summer 2015. July 2020 was Phoenix's warmest month on record with a mean temperature of 98.9°. The current predominantly warmer than normal pattern will likely persist through much of September, paving the way for a solidly warmer than normal summer and a warm start to fall throughout the region. Occasional short-lived cool shots remain possible. The ENSO Region 1+2 anomaly was -0.9°C and the Region 3.4 anomaly was -0.5°C for the week centered around August 12. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -1.17°C and the ENSO Region 3.4 anomaly has averaged -0.45°C. Neutral-cool conditions will likely into the start of autumn. During the autumn, La Niña conditions will likely develop. The SOI was -3.52. Today, the preliminary Arctic Oscillation (AO) figure was -0.917. On August 16, the MJO was in Phase 8 at an amplitude of 1.635 (RMM). The August 15-adjusted amplitude was 1.367. The MJO's recent passage through Phase 4 at an amplitude of 1.500 or above has been uncommon during the first half of August. During the 1981-2019 period only 1983 and 2019 saw the MJO move through Phase 4 with an amplitude of 1.500 or above during the first half of August. August 1983 had the longest such stretch. Both cases saw the second half of August average generally warmer than normal in the Middle Atlantic region. Both cases also featured a warmer than normal September. Last year, the MJO went through a very strong passage through Phase 1 during the closing days of May. About four weeks later, a warmer than normal pattern locked in and predominated through early autumn. This year, the MJO was in Phase 1 for 3 consecutive days with an amplitude of 1.500 or above during the June 1-3 period. Last year, the SOI fell to -42.04 on June 22 when the MJO was in Phase 6. This year, the SOI plunged below -46.68 on June 5, its lowest level in more than three years. The dramatic plunge in the SOI could be the proverbial spark that kicks off a sequence of events leading to the development of a sustained warmer than normal period. The cases that saw both the MJO and SOI thresholds satisfied generally saw 10-20 days where the temperature reached or exceeded 90° in New York City during the July 1-August 31 period. Since 1990, there have been 11 La Niña events, 6 of which followed an El Niño winter. 10/11 (91%) case saw warmer than normal September. All 6 following an El Niño winter were warmer than normal. September mean temperatures for New York City for those cases were: 11 cases: 69.9°; Subset of 6 cases: 70.8°; Entire 1990-2019 period: 69.0°. The September mean temperature for all La Niña and neutral-cool cases following an El Niño winter (1950-2019: n=13) was 69.9°. Overall, the evolution of ENSO, along with the observed ongoing monthly warming (1.6°/decade in NYC and 1.5°/decade in the Northeast Region during September 1990-2019), favors a warmer than normal September. Since 1950, there have been five cases where a La Niña developed during June-July-August or afterward following an El Niño winter. 4/5 (80%) of those cases saw a predominant EPO+/AO+ winter pattern. The most recent such case was 2016-17. 9/10 (90%) of the La Niña winters that followed an El Niño winter featured a predominantly positive EPO. Based on sensitivity analysis applied to the latest guidance, there is an implied 74% probability that New York City will have a warmer than normal August. August will likely finish with a mean temperature near 77.0°.

Yes, LaGuardia's record-breaking 44-day streak (July 3 through August 15) during which the temperature remained at or above 70 degrees or above ended. The previous record was 34 days, which was set July 8 through August 10, 2006. Islip had a high temperature of 69 degrees yesterday and White Plains only reached 68. Rainfall totals were not impressive around the area.

At White Plains, the temperature fell to 59 degrees this morning. That ended the 58-day stretch (June 20 through August 16) during which the minimum temperature was 60 degrees or above. The old record of 53 days was set during June 27 through August 18 in 2012.

Morning thoughts... In the wake of yesterday’s rainfall, the temperature fell to the coolest levels since near mid-June in parts of the region. At New York City, the temperature fell to 64 degrees, its coolest figure since June 17 when the temperature fell to 60 degrees. At Newark, the temperature fell to 64 degrees. The last time it was at least as cool there was on June 18 when the temperature dropped to 64 degrees. After a cool start, temperatures will reach the upper 70s and lower 80s across the region today. Parts of the region could see some thunderstorms during the afternoon or evening hours. Out west, intense heat will again topple records in parts of California, Arizona and Nevada. Death Valley reached 130 degrees yesterday. That smashed the August monthly record of 127 degrees, which was set on August 12, 1933 and tied on August 3, 1993 and August 1, 2017. That was also Death Valley’s hottest temperature since July 13, 1913 when the mercury reached 131 degrees. However, there are questions about the accuracy of the July 1913 temperatures, which were far above what would have been expected from temperatures reported on the same dates elsewhere in the region. https://www.wunderground.com/blog/weatherhistorian/an-investigation-of-death-valleys-134f-world-temperature-record.html Unlike in July 1913, many areas in the Southwest recorded daily and even monthly record high temperatures. One location recorded an all-time high temperature. In short, yesterday’s 130-degree temperature could have become the world’s highest reliably recorded temperature on record. In addition, Phoenix reached 115 degrees. That was the 8th time this year that Phoenix reached 115 degrees or above. The prior record was 7 times in 1974.

Parts of the region experienced a soaking rainfall today with temperatures topping out mainly in the lower 70s. At New York City, the high temperature was 72°. The last time August had a maximum temperature of 72° or below was August 19, 2018 when the temperature also reached 72°. Rainfall amounts included: Baltimore: 1.06" Islip: 0.58" New York City: 0.21" Newark: 0.14" Philadelphia: 0.63" Poughkeepsie: 0.12" Washington, DC: 1.03" Wilmington, DE: 1.04" Out west, extreme heat again prevailed in the Southwest. Select high temperatures included: Bishop, CA: 108° (old record: 106°, 1994) Death Valley, CA: 128° (old record: 124°, 1994 and 2002) ***New August Record*** Everett, WA: 99° (old record: 87°, 2010 and 2012) ***New August Record*** Flagstaff: 93° (old record: 89°, 1939) ***Tied August Record*** Kingman, AZ: 109° Lake Havasu City, AZ: 117° Las Vegas: 113° (tied record set in 1939) Lemoore, CA: 120° (old record: 109°, 1967) ***New All-Time Record*** Mesa, AZ: 113° (old record: 108°, 2019) Modesto, CA: 111° (old record: 104, 1992, 2015 and 2019) ***New August Record*** Needles, CA: 117° Palm Springs, CA: 114° Phoenix: 115° (old record: 113°, 1992 and 2013) Sacramento: 112° (old record: 106°, 1992 and 2015) ***New August Record*** Seattle: 97° Stockton, CA: 113° (old record: 106°, 1983) ***New August Record*** Tucson: 110° (old record: 108° 1992 and 2013) Yuma, AZ: 113° Death Valley reached 125° or above for the second consecutive day. The last time that happened in August was August 9-10, 2012. Final figures should be available for Death Valley and Lake Havasu City tomorrow. More intense heat is likely in that region through midweek. Phoenix has an implied 93% probability of having its warmest summer on record. Phoenix will likely finish with a summer mean temperature of 96.2° - 96.6°. The existing record is 95.1°, which was set in summer 2013 and tied in summer 2015. July 2020 was Phoenix's warmest month on record with a mean temperature of 98.9°. Today was also Phoenix's 40th day on which the temperature reached 110° or above. The old record was 33 days, which was set in 2011. Following the storm, readings will warm up tomorrow and Tuesday. The current predominantly warmer than normal pattern will likely persist through much of September, paving the way for a solidly warmer than normal summer and a warm start to fall throughout the region. Occasional short-lived cool shots remain possible. The ENSO Region 1+2 anomaly was -1.2°C and the Region 3.4 anomaly was -0.6°C for the week centered around August 5. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -1.15°C and the ENSO Region 3.4 anomaly has averaged -0.37°C. Neutral-cool conditions will likely into the start of autumn. During the autumn, La Niña conditions will likely develop. The SOI was +5.46. Today, the preliminary Arctic Oscillation (AO) figure was -0.449. On August 15, the MJO was in Phase 8 at an amplitude of 1.363 (RMM). The August 14-adjusted amplitude was 0.836. The MJO's recent passage through Phase 4 at an amplitude of 1.500 or above has been uncommon during the first half of August. During the 1981-2019 period only 1983 and 2019 saw the MJO move through Phase 4 with an amplitude of 1.500 or above during the first half of August. August 1983 had the longest such stretch. Both cases saw the second half of August average generally warmer than normal in the Middle Atlantic region. Both cases also featured a warmer than normal September. Last year, the MJO went through a very strong passage through Phase 1 during the closing days of May. About four weeks later, a warmer than normal pattern locked in and predominated through early autumn. This year, the MJO was in Phase 1 for 3 consecutive days with an amplitude of 1.500 or above during the June 1-3 period. Last year, the SOI fell to -42.04 on June 22 when the MJO was in Phase 6. This year, the SOI plunged below -46.68 on June 5, its lowest level in more than three years. The dramatic plunge in the SOI could be the proverbial spark that kicks off a sequence of events leading to the development of a sustained warmer than normal period. The cases that saw both the MJO and SOI thresholds satisfied generally saw 10-20 days where the temperature reached or exceeded 90° in New York City during the July 1-August 31 period. Since 1990, there have been 11 La Niña events, 6 of which followed an El Niño winter. 10/11 (91%) case saw warmer than normal September. All 6 following an El Niño winter were warmer than normal. September mean temperatures for New York City for those cases were: 11 cases: 69.9°; Subset of 6 cases: 70.8°; Entire 1990-2019 period: 69.0°. The September mean temperature for all La Niña and neutral-cool cases following an El Niño winter (1950-2019: n=13) was 69.9°. Overall, the evolution of ENSO, along with the observed ongoing monthly warming (1.6°/decade in NYC and 1.5°/decade in the Northeast Region during September 1990-2019), favors a warmer than normal September. Since 1950, there have been five cases where a La Niña developed during June-July-August or afterward following an El Niño winter. 4/5 (80%) of those cases saw a predominant EPO+/AO+ winter pattern. The most recent such case was 2016-17. 9/10 (90%) of the La Niña winters that followed an El Niño winter featured a predominantly positive EPO. Based on sensitivity analysis applied to the latest guidance, there is an implied 73% probability that New York City will have a warmer than normal August. August will likely finish with a mean temperature near 77.0°.

Yes. Central Park had an 80.0 mean temperature.

Four photos of the leaf burn following Tropical Storm Isiais (Larchmont, NY):

I agree.

At 12 pm, the temperature at LaGuardia Airport was 69°. That ended LaGuardia's record-breaking 44-day streak (July 3 through August 15) during which the temperature remained at or above 70°. The previous record was 34 days, which was set July 8 through August 10, 2006.

Morning thoughts... At 8 am, moderate rainfall was moving through area that included parts of Virginia, Maryland, Delaware, Pennsylvania and New Jersey. Another smaller area of moderate rainfall was moving through parts of the Hudson Valley. In New York City, light rain was falling with a temperature of 67 degrees. A moderate to heavy rainfall remains likely parts of the Middle Atlantic region. Virginia, Maryland, Delaware, Pennsylvania and southern New Jersey could be in line for 1”-2” rain with locally higher amounts. Parts of Long Island could see 0.50”-1.00” rain. New York City will likely see less than 0.50”. Out west, intense heat will again sear parts of California, Arizona and Nevada. Death Valley is poised to challenge the August heat record. Yesterday’s high temperature there was 126 degrees, which beat the daily record of 124 degrees from 2002. Yesterday’s high temperature was just below the monthly record of 127 degrees, which was set on August 12, 1933 and tied on August 1, 2017.

Under partly sunny skies, temperatures reached the upper 70s and lower 80s in much of the region. Coastal areas saw a stiff northeast breeze. Out west, extreme heat prevailed in the Southwest. Select high temperatures included: Death Valley, CA: 125° (old record: 124°, 2002) Kingman, AZ: 111° (old record: 106°, 1933) ***Tied August Record*** Lake Havasu City, AZ: 120° (old record: 118°, 1994) Las Vegas: 113° (old record: 111°, 1939, 1994 and 2002) Mesa, AZ: 112° (tied daily record set in 2019) Needles, CA: 123° (old record: 118°, 2019) ***New August Record*** Phoenix: 114° Tucson: 109° Yuma, AZ: 111° Final figures will be available for Death Valley and Lake Havasu City tomorrow. More intense heat is likely in that region through midweek next week. Tomorrow could see some showers and perhaps periods of rain with readings mainly in the 70s. From southern New Jersey southward to Virginia, a soaking rain is in store. There, widespread 1"-2" with locally higher amounts is likely. A moderate rainfall of 0.50"-1.00" is possible on portions of Long Island. Nevertheless, the current predominantly warmer than normal pattern will likely persist through much of September, paving the way for a solidly warmer than normal summer and a warm start to fall throughout the region. Occasional short-lived cool shots remain possible. The ENSO Region 1+2 anomaly was -1.2°C and the Region 3.4 anomaly was -0.6°C for the week centered around August 5. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -1.15°C and the ENSO Region 3.4 anomaly has averaged -0.37°C. Neutral-cool conditions will likely into the start of autumn. During the autumn, La Niña conditions will likely develop. The SOI was +5.46. Today, the preliminary Arctic Oscillation (AO) figure was -0.097. On August 14, the MJO was in Phase 8 at an amplitude of 0.836 (RMM). The August 13-adjusted amplitude was 0.617. The MJO's recent passage through Phase 4 at an amplitude of 1.500 or above has been uncommon during the first half of August. During the 1981-2019 period only 1983 and 2019 saw the MJO move through Phase 4 with an amplitude of 1.500 or above during the first half of August. August 1983 had the longest such stretch. Both cases saw the second half of August average generally warmer than normal in the Middle Atlantic region. Both cases also featured a warmer than normal September. Last year, the MJO went through a very strong passage through Phase 1 during the closing days of May. About four weeks later, a warmer than normal pattern locked in and predominated through early autumn. This year, the MJO was in Phase 1 for 3 consecutive days with an amplitude of 1.500 or above during the June 1-3 period. Last year, the SOI fell to -42.04 on June 22 when the MJO was in Phase 6. This year, the SOI plunged below -46.68 on June 5, its lowest level in more than three years. The dramatic plunge in the SOI could be the proverbial spark that kicks off a sequence of events leading to the development of a sustained warmer than normal period. The cases that saw both the MJO and SOI thresholds satisfied generally saw 10-20 days where the temperature reached or exceeded 90° in New York City during the July 1-August 31 period. Since 1990, there have been 11 La Niña events, 6 of which followed an El Niño winter. 10/11 (91%) case saw warmer than normal September. All 6 following an El Niño winter were warmer than normal. September mean temperatures for New York City for those cases were: 11 cases: 69.9°; Subset of 6 cases: 70.8°; Entire 1990-2019 period: 69.0°. The September mean temperature for all La Niña and neutral-cool cases following an El Niño winter (1950-2019: n=13) was 69.9°. Overall, the evolution of ENSO, along with the observed ongoing monthly warming (1.6°/decade in NYC and 1.5°/decade in the Northeast Region during September 1990-2019), favors a warmer than normal September. Since 1950, there have been five cases where a La Niña developed during June-July-August or afterward following an El Niño winter. 4/5 (80%) of those cases saw a predominant EPO+/AO+ winter pattern. The most recent such case was 2016-17. 9/10 (90%) of the La Niña winters that followed an El Niño winter featured a predominantly positive EPO. Based on sensitivity analysis applied to the latest guidance, there is an implied 73% probability that New York City will have a warmer than normal August. August will likely finish with a mean temperature near 77.0°.

Morning thoughts... Readings will generally rise into the lower 80s across the region today. Some areas could top out in the middle 80s. Tomorrow, a system will bring a moderate to heavy rainfall to parts of the Middle Atlantic region. Virginia, Maryland, Delaware, Pennsylvania and southern New Jersey could be in line for 1”-2” rain with locally higher amounts. There is uncertainty how far north the steady rain will come. New York City could see only showers and perhaps a period of rain if the ECMWF is accurate. Out west, a period of intense heat will be searing parts of California, Arizona and Nevada. Death Valley is poised to challenge the August heat record. Yesterday’s high temperature there was 124 degrees, which was just below the daily record of 125 degrees from 1996. That was the hottest August temperature since the mercury hit 127 degrees on August 1, 2017. Today through Tuesday should be several degrees warmer. The August record is 127 degrees. That record was set on August 12, 1933 and tied on August 3, 1993 and August 1, 2017. Earlier this summer, Death Valley recorded a 128-degree high temperature on July 12. That was Death Valley’s highest temperature since July 4, 2013 when the thermometer also reached 128 degrees.

Temperatures rose into the middle and, in places, upper 80s today. Tomorrow will be cooler with highs in the lower 80s. Sunday could see some showers and perhaps periods of rain with readings mainly in the 70s. Nevertheless, the current predominantly warmer than normal pattern will likely persist through much of September, paving the way for a solidly warmer than normal summer and a warm start to fall throughout the region. Occasional short-lived cool shots remain possible. The ENSO Region 1+2 anomaly was -1.2°C and the Region 3.4 anomaly was -0.6°C for the week centered around August 5. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -1.15°C and the ENSO Region 3.4 anomaly has averaged -0.37°C. Neutral-cool conditions will likely into the start of autumn. During the autumn, La Niña conditions will likely develop. The SOI was +1.76. Today, the preliminary Arctic Oscillation (AO) figure was -0.181. On August 13, the MJO was in Phase 7 at an amplitude of 0.618 (RMM). The August 12-adjusted amplitude was 0.327. Some of the guidance suggests that the MJO could be in Phase 8 in late August. The convergence of the MJO's passage through phase 8 and revived tropical cyclone activity could suggest the possibility of an East Coast threat during the August 20-September 10 period. Phases 8-1-2 have coincided with a cluster of East Coast landfalls. Belle (1976) and Gloria (1985) made landfall when the MJO was in Phase 8 at a low amplitude. Sandy (2012) and Fay (2020) made landfall when the MJO was in Phase 2. The MJO's recent passage through Phase 4 at an amplitude of 1.500 or above has been uncommon during the first half of August. During the 1981-2019 period only 1983 and 2019 saw the MJO move through Phase 4 with an amplitude of 1.500 or above during the first half of August. August 1983 had the longest such stretch. Both cases saw the second half of August average generally warmer than normal in the Middle Atlantic region. Both cases also featured a warmer than normal September. Last year, the MJO went through a very strong passage through Phase 1 during the closing days of May. About four weeks later, a warmer than normal pattern locked in and predominated through early autumn. This year, the MJO was in Phase 1 for 3 consecutive days with an amplitude of 1.500 or above during the June 1-3 period. Last year, the SOI fell to -42.04 on June 22 when the MJO was in Phase 6. This year, the SOI plunged below -46.68 on June 5, its lowest level in more than three years. The dramatic plunge in the SOI could be the proverbial spark that kicks off a sequence of events leading to the development of a sustained warmer than normal period. The cases that saw both the MJO and SOI thresholds satisfied generally saw 10-20 days where the temperature reached or exceeded 90° in New York City during the July 1-August 31 period. Since 1990, there have been 11 La Niña events, 6 of which followed an El Niño winter. 10/11 (91%) case saw warmer than normal September. All 6 following an El Niño winter were warmer than normal. September mean temperatures for New York City for those cases were: 11 cases: 69.9°; Subset of 6 cases: 70.8°; Entire 1990-2019 period: 69.0°. The September mean temperature for all La Niña and neutral-cool cases following an El Niño winter (1950-2019: n=13) was 69.9°. Overall, the evolution of ENSO, along with the observed ongoing monthly warming (1.6°/decade in NYC and 1.5°/decade in the Northeast Region during September 1990-2019), favors a warmer than normal September. Since 1950, there have been five cases where a La Niña developed during June-July-August or afterward following an El Niño winter. 4/5 (80%) of those cases saw a predominant EPO+/AO+ winter pattern. The most recent such case was 2016-17. 9/10 (90%) of the La Niña winters that followed an El Niño winter featured a predominantly positive EPO. Based on sensitivity analysis applied to the latest guidance, there is an implied 71% probability that New York City will have a warmer than normal August. August will likely finish with a mean temperature near 77.0°.

With today's rainfall, New York City has received 26.28" precipitation this year. That is 4.50" below normal. Based on the 1971-2019 data, there is an implied 83% probability that New York City will receive 40" or more precipitation this year. However, there is just an implied 23% probability that it will receive at least 50" precipitation. The high temperature will rise into the lower to middle 80s tomorrow and then the upper 70s and lower 80s during the coming weekend. Nevertheless, the current predominantly warmer than normal pattern will likely persist through much of September, paving the way for a solidly warmer than normal summer and a warm start to fall throughout the region. Occasional short-lived cool shots remain possible. The ENSO Region 1+2 anomaly was -1.2°C and the Region 3.4 anomaly was -0.6°C for the week centered around August 5. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -1.15°C and the ENSO Region 3.4 anomaly has averaged -0.37°C. Neutral-cool conditions will likely into the start of autumn. During the autumn, La Niña conditions will likely develop. The SOI was -5.95. Today, the preliminary Arctic Oscillation (AO) figure was -0.332. On August 12, the MJO was in Phase 6 at an amplitude of 0.328 (RMM). The August 11-adjusted amplitude was 0.421. Some of the guidance suggests that the MJO could be in Phase 8 in late August. The convergence of the MJO's passage through phase 8 and revived tropical cyclone activity could suggest the possibility of an East Coast threat during the August 20-September 10 period. Phases 8-1-2 have coincided with a cluster of East Coast landfalls. Belle (1976) and Gloria (1985) made landfall when the MJO was in Phase 8 at a low amplitude. Sandy (2012) and Fay (2020) made landfall when the MJO was in Phase 2. The MJO's recent passage through Phase 4 at an amplitude of 1.500 or above has been uncommon during the first half of August. During the 1981-2019 period only 1983 and 2019 saw the MJO move through Phase 4 with an amplitude of 1.500 or above during the first half of August. August 1983 had the longest such stretch. Both cases saw the second half of August average generally warmer than normal in the Middle Atlantic region. Both cases also featured a warmer than normal September. Last year, the MJO went through a very strong passage through Phase 1 during the closing days of May. About four weeks later, a warmer than normal pattern locked in and predominated through early autumn. This year, the MJO was in Phase 1 for 3 consecutive days with an amplitude of 1.500 or above during the June 1-3 period. Last year, the SOI fell to -42.04 on June 22 when the MJO was in Phase 6. This year, the SOI plunged below -46.68 on June 5, its lowest level in more than three years. The dramatic plunge in the SOI could be the proverbial spark that kicks off a sequence of events leading to the development of a sustained warmer than normal period. The cases that saw both the MJO and SOI thresholds satisfied generally saw 10-20 days where the temperature reached or exceeded 90° in New York City during the July 1-August 31 period. Since 1990, there have been 11 La Niña events, 6 of which followed an El Niño winter. 10/11 (91%) case saw warmer than normal September. All 6 following an El Niño winter were warmer than normal. September mean temperatures for New York City for those cases were: 11 cases: 69.9°; Subset of 6 cases: 70.8°; Entire 1990-2019 period: 69.0°. The September mean temperature for all La Niña and neutral-cool cases following an El Niño winter (1950-2019: n=13) was 69.9°. Overall, the evolution of ENSO, along with the observed ongoing monthly warming (1.6°/decade in NYC and 1.5°/decade in the Northeast Region during September 1990-2019), favors a warmer than normal September. Since 1950, there have been five cases where a La Niña developed during June-July-August or afterward following an El Niño winter. 4/5 (80%) of those cases saw a predominant EPO+/AO+ winter pattern. The most recent such case was 2016-17. 9/10 (90%) of the La Niña winters that followed an El Niño winter featured a predominantly positive EPO. Based on sensitivity analysis applied to the latest guidance, there is an implied 70% probability that New York City will have a warmer than normal August. August will likely finish with a mean temperature near 77.0°.

Morning thoughts... At 9:20 am, a cluster of slow-moving thunderstorms was approaching Newark. It was also expanding eastward, meaning that a shower or thundershower could occur in New York City this morning. Further north, several hours of sunshine should be the rule in such areas as Poughkeepsie. Much of the region will likely see temperatures top out in the lower and middle 80s.

Yes, it’s a meta analysis.

Temperatures reached the upper 80s and lower 90s across the region today. In addition, scattered heavy thunderstorms brought drenching rains to parts of the area. Philadelphia picked up 1.44" rain and New York City received 1.76" rain. 90° Days for Select Cities (through August 12): Albany: 13 (2019: 12 days) Allentown: 23 (2019: 24 days) Baltimore: 40 (2019: 59 days) Boston: 14 (2019: 15 days) Burlington: 20 (2019: 8 days) Harrisburg: 29 (2019: 33 days) Islip: 6 (2019: 8 days) New York City-JFK: 10 (2019: 7 days) New York City-LGA: 30 (2019: 26 days) New York City-NYC: 18 (2019: 15 days) Newark: 27 (2019: 28 days) Philadelphia: 32 (2019: 35 days) Scranton: 23 (2019: 12 days) Washington, DC: 41 (2019: 62 days) New York City-Newark Average: 21 (2019: 19 days) ...Expected: 21 (based on regression equation tied to JFK-LGA-EWR data) The next several days will be somewhat cooler than today. Temperatures will be in the lower to middle 80s and then the upper 70s and lower 80s during the coming weekend. Nevertheless, the current predominantly warmer than normal pattern will likely persist through much of September, paving the way for a solidly warmer than normal summer and a warm start to fall throughout the region. Occasional short-lived cool shots remain possible. The ENSO Region 1+2 anomaly was -1.2°C and the Region 3.4 anomaly was -0.6°C for the week centered around August 5. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -1.15°C and the ENSO Region 3.4 anomaly has averaged -0.37°C. Neutral-cool conditions will likely into the start of autumn. During the autumn, La Niña conditions will likely develop. The SOI was -8.56. Today, the preliminary Arctic Oscillation (AO) figure was -0.627. On August 11, the MJO was in Phase 5 at an amplitude of 0.425 (RMM). The August 10-adjusted amplitude was 0.793. Some of the guidance suggests that the MJO could be in Phase 8 in late August. The convergence of the MJO's passage through phase 8 and revived tropical cyclone activity could suggest the possibility of an East Coast threat during the August 20-September 10 period. Phases 8-1-2 have coincided with a cluster of East Coast landfalls. Belle (1976) and Gloria (1985) made landfall when the MJO was in Phase 8 at a low amplitude. Sandy (2012) and Fay (2020) made landfall when the MJO was in Phase 2. The MJO's recent passage through Phase 4 at an amplitude of 1.500 or above has been uncommon during the first half of August. During the 1981-2019 period only 1983 and 2019 saw the MJO move through Phase 4 with an amplitude of 1.500 or above during the first half of August. August 1983 had the longest such stretch. Both cases saw the second half of August average generally warmer than normal in the Middle Atlantic region. Both cases also featured a warmer than normal September. Last year, the MJO went through a very strong passage through Phase 1 during the closing days of May. About four weeks later, a warmer than normal pattern locked in and predominated through early autumn. This year, the MJO was in Phase 1 for 3 consecutive days with an amplitude of 1.500 or above during the June 1-3 period. Last year, the SOI fell to -42.04 on June 22 when the MJO was in Phase 6. This year, the SOI plunged below -46.68 on June 5, its lowest level in more than three years. The dramatic plunge in the SOI could be the proverbial spark that kicks off a sequence of events leading to the development of a sustained warmer than normal period. The cases that saw both the MJO and SOI thresholds satisfied generally saw 10-20 days where the temperature reached or exceeded 90° in New York City during the July 1-August 31 period. Since 1990, there have been 11 La Niña events, 6 of which followed an El Niño winter. 10/11 (91%) case saw warmer than normal September. All 6 following an El Niño winter were warmer than normal. September mean temperatures for New York City for those cases were: 11 cases: 69.9°; Subset of 6 cases: 70.8°; Entire 1990-2019 period: 69.0°. The September mean temperature for all La Niña and neutral-cool cases following an El Niño winter (1950-2019: n=13) was 69.9°. Overall, the evolution of ENSO, along with the observed ongoing monthly warming (1.6°/decade in NYC and 1.5°/decade in the Northeast Region during September 1990-2019), favors a warmer than normal September. Since 1950, there have been five cases where a La Niña developed during June-July-August or afterward following an El Niño winter. 4/5 (80%) of those cases saw a predominant EPO+/AO+ winter pattern. The most recent such case was 2016-17. 9/10 (90%) of the La Niña winters that followed an El Niño winter featured a predominantly positive EPO. Based on sensitivity analysis applied to the latest guidance, there is an implied 71% probability that New York City will have a warmer than normal August. August will likely finish with a mean temperature near 77.0°.

LGA 1.32” in the past hour.

Over the past hour, the temperature crashed from a daily high of 93 degrees to 73 degrees in Philadelphia as a heavy thunderstorm moved in. 1.00” rain was recorded during for the hourly period ending at 2:54 pm.

12z guidance (RGEM, NAM, and HRRR) are in line with Walt Drag’s thinking.