donsutherland1

Temperatures rose into the upper 80s and lower 90s across the region. Tomorrow will be a similar day. Temperatures will generally remain near or above normal through the remainder of the month. There is potential for significant heat to expand into the region during the first week of August. Overall, August will likely be warmer than normal. During June 16-20, the MJO has been in Phase 1 at an amplitude of 1.500 or above. Of the six cases that saw such an outcome during June 15-25 (1988, 2003, 2010, 2012, 2017 and 2020), four had a warmer than normal July, one was somewhat cooler than normal and one was cooler than normal. The latest guidance all indicates that July will wind up solidly among the warmer than normal cases. The ECMWF seasonal forecast indicates that the summer will be warmer than normal throughout the region and across much of North America. Based on how the pattern has been evolving during the spring transition to summer, it is more likely than not that the warmest anomalies of the summer will likely occur in July and August with June being the coolest of the three months in the Northeast. The latest ECMWF monthly forecast indicates that July will be warmer than June relative to normal and that August will be the warmest summer month relative to normal. In addition, in the 6 past cases when the June AO averaged +0.750 or above (1950-2021), 50% of the following July cases were warmer than normal. 67% of the following August and September cases featured above normal temperatures. The ENSO Region 1+2 anomaly was -1.0°C and the Region 3.4 anomaly was -0.7°C for the week centered around July 20. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -1.30°C and the ENSO Region 3.4 anomaly has averaged -0.60°C. La Niña conditions will likely persist through the summer. The SOI was +15.63. The preliminary Arctic Oscillation (AO) was -0.147 today. On July 25 the MJO was in Phase 1 at an amplitude of 1.564 (RMM). The July 24-adjusted amplitude was 1.486 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that New York City will have a warmer than normal July (1991-2020 normal). July will likely finish with a mean temperature near 79.6° (2.1° above normal).

Temperatures will generally remain near or above normal through the remainder of the month. There is potential for significant heat to expand into the region late in the first week of August. Overall, August will likely be warmer than normal. In the Midwest, St. Louis picked up 8.64" rainfall today. That swept away the longstanding daily rainfall record of 6.85", which was set on August 20, 1915. During June 16-20, the MJO has been in Phase 1 at an amplitude of 1.500 or above. Of the six cases that saw such an outcome during June 15-25 (1988, 2003, 2010, 2012, 2017 and 2020), four had a warmer than normal July, one was somewhat cooler than normal and one was cooler than normal. The latest guidance all indicates that July will wind up solidly among the warmer than normal cases. The ECMWF seasonal forecast indicates that the summer will be warmer than normal throughout the region and across much of North America. Based on how the pattern has been evolving during the spring transition to summer, it is more likely than not that the warmest anomalies of the summer will likely occur in July and August with June being the coolest of the three months in the Northeast. The latest ECMWF monthly forecast indicates that July will be warmer than June relative to normal and that August will be the warmest summer month relative to normal. In addition, in the 6 past cases when the June AO averaged +0.750 or above (1950-2021), 50% of the following July cases were warmer than normal. 67% of the following August and September cases featured above normal temperatures. The ENSO Region 1+2 anomaly was -1.0°C and the Region 3.4 anomaly was -0.7°C for the week centered around July 20. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -1.30°C and the ENSO Region 3.4 anomaly has averaged -0.60°C. La Niña conditions will likely persist through the summer. The SOI was +6.89. The preliminary Arctic Oscillation (AO) was -0.015 today. On July 24 the MJO was in Phase 1 at an amplitude of 1.485 (RMM). The July 23-adjusted amplitude was 1.419 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that New York City will have a warmer than normal July (1991-2020 normal). July will likely finish with a mean temperature near 79.6° (2.1° above normal).

Morning thoughts… It will be partly cloudy and warm. High temperatures will reach the lower and middle 80s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 85° Newark: 90° Philadelphia: 88° Tomorrow will turn warmer. Normals: New York City: 30-Year: 85.0°; 15-Year: 86.1° Newark: 30-Year: 86.7°; 15-Year: 88.1° Philadelphia: 30-Year: 87.6°; 15-Year: 88.6°

Tomorrow will be partly sunny with seasonable temperatures. Temperatures will generally remain near orabove normal through the remainder of the month. There is potential for significant heat to expand into the region late in the first week of August. Overall, August will likely be warmer than normal. In the Midwest, St. Louis picked up 8.64" rainfall today. That swept away the longstanding daily rainfall record of 6.85", which was set on August 20, 1915. During June 16-20, the MJO has been in Phase 1 at an amplitude of 1.500 or above. Of the six cases that saw such an outcome during June 15-25 (1988, 2003, 2010, 2012, 2017 and 2020), four had a warmer than normal July, one was somewhat cooler than normal and one was cooler than normal. The latest guidance all indicates that July will wind up solidly among the warmer than normal cases. The ECMWF seasonal forecast indicates that the summer will be warmer than normal throughout the region and across much of North America. Based on how the pattern has been evolving during the spring transition to summer, it is more likely than not that the warmest anomalies of the summer will likely occur in July and August with June being the coolest of the three months in the Northeast. The latest ECMWF monthly forecast indicates that July will be warmer than June relative to normal and that August will be the warmest summer month relative to normal. In addition, in the 6 past cases when the June AO averaged +0.750 or above (1950-2021), 50% of the following July cases were warmer than normal. 67% of the following August and September cases featured above normal temperatures. The ENSO Region 1+2 anomaly was -1.0°C and the Region 3.4 anomaly was -0.7°C for the week centered around July 20. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -1.30°C and the ENSO Region 3.4 anomaly has averaged -0.60°C. La Niña conditions will likely persist through the summer. The SOI was +7.02. The preliminary Arctic Oscillation (AO) was -0.074 today. On July 23 the MJO was in Phase 1 at an amplitude of 1.419 (RMM). The July 22-adjusted amplitude was 1.504 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied 99% probability that New York City will have a warmer than normal July (1991-2020 normal). July will likely finish with a mean temperature near 79.7° (2.2° above normal).

No. It broke the record. The earlier extreme heat event with 5 days did not have 5 consecutive days. It had 5 days in total.

Final data for Newark's extreme heat event:

Historic rainfall is underway in St. Louis. Through 7:15 CDT, 8.09" has fallen. That smashes the daily mark of 2.24" from 2009 and all-time record of 6.85" from August 20, 1915. It has had hourly rainfall as high as 2.21", including 4 consecutive hours with 1" or more of rain.

Morning thoughts… It will be variably cloudy and cooler. High temperatures will reach the lower and middle 80s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 84° Newark: 89° Philadelphia: 84° Tomorrow will be fair and pleasant. Normals: New York City: 30-Year: 85.1°; 15-Year: 86.2° Newark: 30-Year: 86.8°; 15-Year: 88.2° Philadelphia: 30-Year: 87.7°; 15-Year: 88.7°

It will be variably cloudy and somewhat cooler tomorrow. Temperatures will generally remain at or above normal through the remainder of the month. During June 16-20, the MJO has been in Phase 1 at an amplitude of 1.500 or above. Of the six cases that saw such an outcome during June 15-25 (1988, 2003, 2010, 2012, 2017 and 2020), four had a warmer than normal July, one was somewhat cooler than normal and one was cooler than normal. The latest guidance all indicates that July will wind up solidly among the warmer than normal cases. The ECMWF seasonal forecast indicates that the summer will be warmer than normal throughout the region and across much of North America. Based on how the pattern has been evolving during the spring transition to summer, it is more likely than not that the warmest anomalies of the summer will likely occur in July and August with June being the coolest of the three months in the Northeast. The latest ECMWF monthly forecast indicates that July will be warmer than June relative to normal and that August will be the warmest summer month relative to normal. In addition, in the 6 past cases when the June AO averaged +0.750 or above (1950-2021), 50% of the following July cases were warmer than normal. 67% of the following August and September cases featured above normal temperatures. 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 July 13. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -1.40°C and the ENSO Region 3.4 anomaly has averaged -0.60°C. La Niña conditions will likely persist through the summer. The SOI was +4.92. The preliminary Arctic Oscillation (AO) was -0.612 today. On July 23 the MJO was in Phase 1 at an amplitude of 1.417 (RMM). The July 22-adjusted amplitude was 1.504 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied 99% probability that New York City will have a warmer than normal July (1991-2020 normal). July will likely finish with a mean temperature near 79.9° (2.4° above normal).

I agree. I don't think one can automatically assume that the record streak of 100s isn't accurate. If there's an error, it's much less than the 2-3 degrees speculated upon in the article. The prior two rises in error could well have been a function of predominant wind direction.

I ran the numbers against New Brunswick and Harrison. The outcomes are similar, but I excluded Harrison, as there were too many missing values in Harrison’s record vs. 2 for New Brunswick’s. There may be an error (assuming there is no other explanation for the recent decoupling shown below), but it’s probably far closer to 0.5 degrees-1 degree than 2-3 degrees. Other explanations are plausible, thus I use “may.”

Morning thoughts… It will be variably cloudy and hot. Thunderstorms are likely as a cold front moves across the region. Some of the thunderstorms could be severe. High temperatures will reach the lower and middle 90s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 90° Newark: 96° Philadelphia: 93° Tomorrow and Wednesday will be cooler. Normals: New York City: 30-Year: 85.1°; 15-Year: 86.2° Newark: 30-Year: 86.9°; 15-Year: 88.3° Philadelphia: 30-Year: 87.8°; 15-Year: 88.8°

Under abundant sunshine, along with only some wispy high clouds, temperature records were approached, tied, or broken in many parts of the Northeast. High temperatures included: Albany: 97° (old record: 96°, 1941) Allentown: 95° (tied record set in 1999 and tied in 2016) Atlantic City: 99° Baltimore: 97° Boston: 100° (old record: 98°, 1933) Bridgeport: 94° Burlington: 91° Concord: 96° Halifax: 87° (old record: 85°, 1975) Harrisburg: 96° (tied record set in 1965 and tied in 1999 and 2001) Hartford: 96° (tied record set in 1987) Islip: 92° Manchester, NH: 98° (old record: 95°, 2001 New York City-JFK: 96° New York City-LGA: 98° (tied record set in 1999 and tied in 2010) New York City-NYC: 95° Newark: 102° (old record: 99°, 2010) Philadelphia: 99° (old record: 98°, 2011) Poughkeepsie: 96° Providence: 98° (old record: 94°, 1933 and 1987) Scranton: 97° (old record: 95°, 1933 and 2016) St. John's, NL: 87° (old record: 84°, 1952) Washington, DC: 94° Wilmington, DE: 95° With Newark recording a record 5 consecutive 100° high temperatures, it has had a mean high temperature of 92.2° over the past 30 days. The last time that occurred was during June 19-July 18, 2012 when the average temperature was also 92.2°. Tomorrow will be slightly cooler, but temperatures will still reach the lower 90s across much of the region. Afterward, temperatures will become several degrees cooler through midweek. During June 16-20, the MJO has been in Phase 1 at an amplitude of 1.500 or above. Of the six cases that saw such an outcome during June 15-25 (1988, 2003, 2010, 2012, 2017 and 2020), four had a warmer than normal July, one was somewhat cooler than normal and one was cooler than normal. The latest guidance all indicates that July will wind up solidly among the warmer than normal cases. The ECMWF seasonal forecast indicates that the summer will be warmer than normal throughout the region and across much of North America. Based on how the pattern has been evolving during the spring transition to summer, it is more likely than not that the warmest anomalies of the summer will likely occur in July and August with June being the coolest of the three months in the Northeast. The latest ECMWF monthly forecast indicates that July will be warmer than June relative to normal and that August will be the warmest summer month relative to normal. In addition, in the 6 past cases when the June AO averaged +0.750 or above (1950-2021), 50% of the following July cases were warmer than normal. 67% of the following August and September cases featured above normal temperatures. 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 July 13. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -1.40°C and the ENSO Region 3.4 anomaly has averaged -0.60°C. La Niña conditions will likely persist through the summer. The SOI was +2.15. The preliminary Arctic Oscillation (AO) was -1.144 today. On July 22 the MJO was in Phase 1 at an amplitude of 1.504 (RMM). The July 21-adjusted amplitude was 1.148 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied 98% probability that New York City will have a warmer than normal July (1991-2020 normal). July will likely finish with a mean temperature near 80.0° (2.5° above normal).

Morning thoughts… It will be mostly sunny and very hot with near record and record heat. There could be afternoon or evening thunderstorms. High temperatures will reach 95°-100° most of the region. Likely high temperatures around the region include: New York City (Central Park): 96° Newark: 102° Philadelphia: 100° Tomorrow will be somewhat cooler. Normals: New York City: 30-Year: 85,2°; 15-Year: 86.3° Newark: 30-Year: 86.9°; 15-Year: 88.3° Philadelphia: 30-Year: 87.8°; 15-Year: 88.9° Select daily records for July 24: Allentown: 95°, 1999 and 2016 Baltimore: 101°, 2010 Bridgeport: 95°, 2010 Hartford: 96°, 1987 Islip: 96°, 2010 New York City-JFK: 97°, 2010 New York City-LGA: 98°, 1999 and 2010 New York City-NYC: 97°, 1999 and 2010 Newark: 99°, 2010 Philadelphia: 98°, 2011 Poughkeepsie: 100°, 1933 Washington, DC: 101°, 2010 White Plains: 95°, 1952

A hot day that saw temperatures rise into the middle and upper 90s in much of the region has concluded. Tomorrow has the potential to be a few degrees warmer. Tomorrow will feature sunshine with near record and record heat. Highs will reach 95°-100° with higher figures in the lower 100s across much of the region. Select daily records for July 24: Allentown: 95°, 1999 and 2016 Baltimore: 101°, 2010 Bridgeport: 95°, 2010 Hartford: 96°, 1987 Islip: 96°, 2010 New York City-JFK: 97°, 2010 New York City-LGA: 98°, 1999 and 2010 New York City-NYC: 97°, 1999 and 2010 Newark: 99°, 2010 Philadelphia: 98°, 2011 Poughkeepsie: 100°, 1933 Washington, DC: 101°, 2010 White Plains: 95°, 1952 Monday will be slightly cooler, but temperatures will still reach the lower 90s across much of the region. Afterward, temperatures will become several degrees cooler through midweek. During June 16-20, the MJO has been in Phase 1 at an amplitude of 1.500 or above. Of the six cases that saw such an outcome during June 15-25 (1988, 2003, 2010, 2012, 2017 and 2020), four had a warmer than normal July, one was somewhat cooler than normal and one was cooler than normal. The latest guidance all indicates that July will wind up solidly among the warmer than normal cases. The ECMWF seasonal forecast indicates that the summer will be warmer than normal throughout the region and across much of North America. Based on how the pattern has been evolving during the spring transition to summer, it is more likely than not that the warmest anomalies of the summer will likely occur in July and August with June being the coolest of the three months in the Northeast. The latest ECMWF monthly forecast indicates that July will be warmer than June relative to normal and that August will be the warmest summer month relative to normal. In addition, in the 6 past cases when the June AO averaged +0.750 or above (1950-2021), 50% of the following July cases were warmer than normal. 67% of the following August and September cases featured above normal temperatures. 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 July 13. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -1.40°C and the ENSO Region 3.4 anomaly has averaged -0.60°C. La Niña conditions will likely persist through the summer. The SOI was +1.66. The preliminary Arctic Oscillation (AO) was -1.122 today. On July 21 the MJO was in Phase 8 at an amplitude of 1.148 (RMM). The July 20-adjusted amplitude was 0.689 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied 97% probability that New York City will have a warmer than normal July (1991-2020 normal). July will likely finish with a mean temperature near 80.0° (2.5° above normal).

Morning thoughts… It will be mostly sunny and very hot. Thee could be afternoon or evening thunderstorms. High temperatures will reach 95°-100° most of the region. Likely high temperatures around the region include: New York City (Central Park): 96° Newark: 101° Philadelphia: 99° Tomorrow will be another very hot day. Normals: New York City: 30-Year: 85,2°; 15-Year: 86.3° Newark: 30-Year: 87.0°; 15-Year: 88.4° Philadelphia: 30-Year: 87.9°; 15-Year: 88.0°

The ongoing heatwave has now qualified as an Extreme Heat Event (EHE) in Newark. At least 3 days have seen the maximum temperature exceed the 97.5th percentile (98° or above), the average high during that period exceeded the 97.5th percentile, and all high temperatures exceeded the 81st percentile (90° or above) in June-August high temperatures for the 1971-2000 base period (Clarke, et al.,2014).

The hottest temperatures of the year are likely this weekend. Widespread high temperatures of 95°-100° with higher figures in the lower 100s are likely. Monday will be slightly cooler, but temperatures will still reach the lower 90s across much of the region. Afterward, temperatures will become several degrees cooler through midweek. During June 16-20, the MJO has been in Phase 1 at an amplitude of 1.500 or above. Of the six cases that saw such an outcome during June 15-25 (1988, 2003, 2010, 2012, 2017 and 2020), four had a warmer than normal July, one was somewhat cooler than normal and one was cooler than normal. The latest guidance all indicates that July will wind up solidly among the warmer than normal cases. The ECMWF seasonal forecast indicates that the summer will be warmer than normal throughout the region and across much of North America. Based on how the pattern has been evolving during the spring transition to summer, it is more likely than not that the warmest anomalies of the summer will likely occur in July and August with June being the coolest of the three months in the Northeast. The latest ECMWF monthly forecast indicates that July will be warmer than June relative to normal and that August will be the warmest summer month relative to normal. In addition, in the 6 past cases when the June AO averaged +0.750 or above (1950-2021), 50% of the following July cases were warmer than normal. 67% of the following August and September cases featured above normal temperatures. 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 July 13. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -1.40°C and the ENSO Region 3.4 anomaly has averaged -0.60°C. La Niña conditions will likely persist through the summer. The SOI was -2.89. The preliminary Arctic Oscillation (AO) was -1.260 today. On July 20 the MJO was in Phase 8 at an amplitude of 0.690 (RMM). The July 19-adjusted amplitude was 0.128 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied 95% probability that New York City will have a warmer than normal July (1991-2020 normal). July will likely finish with a mean temperature near 80.0° (2.5° above normal).

Phoenix recorded just its 7th 95-degree low on record this morning. Records go back to August 1895.

From Teterboro:

A westerly wind is a downsloping wind. It leads to heating in such cities as Newark and Hartford, which often wind up much warmer than other localities that are less impacted by the downsloping winds. A simple explanation of the link between downsloping winds and rising temperatures from the Binghamton office of the National Weather Service is: As a parcel of air rises, there is less and less air above it so the air parcel expands due to the decreasing surrounding air pressure. Likewise, as an air parcel descends there is more and more air above it so the parcel becomes compressed. The Ideal Gas Law (PV=nRT) tells us that if the pressure of an air parcel changes but all other aspects of the parcel remain the same, there must be a corresponding change in temperature to keep the equation balanced. Thus, rising air expands and cools while descending air compresses and warms. https://www.weather.gov/bgm/WeatherInActionDownSlopeWinds

Morning thoughts… It will be mostly sunny and hot. Thee could be afternoon or evening thunderstorms. High temperatures will reach the middle and upper 90s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 92° Newark: 99° Philadelphia: 98° Hot weather will continue through at least the weekend. Normals: New York City: 30-Year: 85,2°; 15-Year: 86.4° Newark: 30-Year: 87.1°; 15-Year: 88.5° Philadelphia: 30-Year: 88.0°; 15-Year: 89.1°

The wind was off the Potomac River for much of the day.

The longest heatwave so far this summer is now underway. Much of the region saw temperatures rise into the middle 90s with some hotter spots. Highs included: Albany: 96° Baltimore: 95° Boston: 92° Bridgeport: 93° Burlington: 93° Hartford: 97° Islip: 95° New York City-JFK: 95° New York City-LGA: 97° New York City-NYC: 95° Newark: 100° Philadelphia: 96° Washington, DC: 91° The heat will continue through at least the weekend. The hottest temperatures will likely be west of New York City in adjacent New Jersey where temperatures could peak in the upper 90s and likely reach or exceed 100° on the hottest days. During June 16-20, the MJO has been in Phase 1 at an amplitude of 1.500 or above. Of the six cases that saw such an outcome during June 15-25 (1988, 2003, 2010, 2012, 2017 and 2020), four had a warmer than normal July, one was somewhat cooler than normal and one was cooler than normal. The latest guidance all indicates that July will wind up solidly among the warmer than normal cases. The ECMWF seasonal forecast indicates that the summer will be warmer than normal throughout the region and across much of North America. Based on how the pattern has been evolving during the spring transition to summer, it is more likely than not that the warmest anomalies of the summer will likely occur in July and August with June being the coolest of the three months in the Northeast. The latest ECMWF monthly forecast indicates that July will be warmer than June relative to normal and that August will be the warmest summer month relative to normal. In addition, in the 6 past cases when the June AO averaged +0.750 or above (1950-2021), 50% of the following July cases were warmer than normal. 67% of the following August and September cases featured above normal temperatures. 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 July 13. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -1.40°C and the ENSO Region 3.4 anomaly has averaged -0.60°C. La Niña conditions will likely persist through the summer. The SOI was +2.22. The preliminary Arctic Oscillation (AO) was -1.109 today. On July 18 the MJO was in Phase 5 at an amplitude of 0.337 (RMM). The July 17-adjusted amplitude was 0.735 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied 90% probability that New York City will have a warmer than normal July (1991-2020 normal). July will likely finish with a mean temperature near 79.8° (2.3° above normal).

LaGuardia Airport had a low temperature of 80° this morning. The number of such minimum temperatures has increased dramatically in recent years, both annually and during July. During 1961-1990, there were 10 low temperatures of 80° or above. During 1991-2020, there were 38 such temperatures. Low temperatures below 60° have become rare. During 1961-1990 there were 16 such days. During 1991-2020, there were 4. Overall, the average July low temperature at LaGuardia Airport has increased from 68.9° during 1961-1990 to 71.4° during 1991-2020. The July distribution of low temperatures is below: