donsutherland1

Morning thoughts… Today will be variably cloudy, breezy, and a bit warmer. A shower is possible, especially in western parts of the region. High temperatures will likely reach the upper 70s and lower 80s. Likely high temperatures around the region include: New York City (Central Park): 77° Newark: 81° Philadelphia: 82° Normals: New York City: 30-Year: 81.5°; 15-Year: 81.3° Newark: 30-Year: 82.9°; 15-Year: 82.9° Philadelphia: 30-Year: 84.1°; 15-Year: 83.8° Powerful Hurricane Ida will make landfall along the Louisiana coast as a Category 4 hurricane. There is a small possibility that it could peak as a category 5 hurricane near or during landfall. Its rains will likely impact the Middle Atlantic region during midweek.

Today was mainly cloudy and cool in the New York City area. Parts of Suffolk County picked up 3"-6" of rain. Philadelphia also picked up a daily record 3.17" (old record: 2.33", 1978). During the 2000-21 period, Philadelphia has averaged 0.9 days per year during which 3" or more of precipitation was recorded. That is triple the annual average for the 1872-1999 period. Tomorrow will be variably cloudy and a bit warmer. A few locations could see a shower or two. Looking farther ahead, September will likely feature near normal to somewhat warmer than normal temperatures overall. Ida will likely make landfall along the Louisiana coast as a Category 4 hurricane. A widespread 10"-15" rainfall with locally higher amounts is likely along its path. Fall 2021 will likely be wetter to much wetter than normal in the northern Middle Atlantic region. Since 1869, there have been 9 August cases where New York City picked up 20.00" or more rainfall during the summer. Two thirds of those cases (and 4/5 of those with summer mean temperatures of 73.0° or above) had 17.00" or more fall precipitation in New York City. 2011 is probably the closest match in terms of precipitation and a nearly identical summer mean temperature. Mean fall precipitation for those 9 cases was 14.86". The median was 17.35". The 1991-2020 normal value is 12.27". The ENSO Region 1+2 anomaly was -0.1°C and the Region 3.4 anomaly was -0.9°C for the week centered around August 18. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.41°C and the ENSO Region 3.4 anomaly has averaged -0.43°C. Neutral ENSO conditions will likely prevail into mid-September. Afterward, La Niña could begin to develop. The SOI was +4.43 today. The preliminary Arctic Oscillation (AO) figure was -0.662 today. On August 26 the MJO was in Phase 2 at an amplitude of 0.1.291 (RMM). The August 25-adjusted amplitude was 0.752 (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 August (1991-2020 normal). August will likely finish with a mean temperature near 77.6° (1.6° above normal).

it was cloudy, breezy, and cool today in the New York Botanical Garden. The temperature was in the 70s throughout the afternoon.

Here’s some other data: Threshold Search for Maximum Temperature (F) New York-Kennedy Airport Area (NY) JFKthr 9 Lat/Lon/Elev: / / Years: 1990 to 2021 Dates: 01-01 to 12-31 Condition is: Maximum Temperature (F) greater than or equal to 90 To sort multiple columns, hold SHIFT while clicking on the columns. Year Jan Feb Mar Apr May Jun Jul Aug* Sep Oct Nov Dec Annual 1990 0 0 0 0 0 0 5 1 0 0 0 0 6 1991 0 0 0 0 3 4 6 3 1 0 0 0 17 1992 0 0 0 0 1 0 5 0 0 0 0 0 6 1993 0 0 0 0 0 1 8 2 2 0 0 0 13 1994 0 0 0 0 0 2 5 0 0 0 0 0 7 1995 0 0 0 0 0 3 4 8 0 0 0 0 15 1996 0 0 0 0 2 1 0 0 1 0 0 0 4 1997 0 0 0 0 0 3 5 2 0 0 0 0 10 1998 0 0 0 0 0 1 2 1 1 0 0 0 5 1999 0 0 0 0 0 2 11 1 0 0 0 0 14 2000 0 0 0 0 0 2 2 2 0 0 0 0 6 2001 0 0 0 0 0 3 1 4 0 0 0 0 8 2002 0 0 0 1 0 3 11 6 0 0 0 0 21 2003 0 0 0 0 0 4 4 4 0 0 0 0 12 2004 0 0 0 0 0 1 0 0 0 0 0 0 1 2005 0 0 0 0 0 1 5 10 1 0 0 0 17 2006 0 0 0 0 0 0 6 6 0 0 0 0 12 2007 0 0 0 0 0 1 1 4 0 1 0 0 7 2008 0 0 0 0 0 4 4 1 0 0 0 0 9 2009 0 0 0 0 0 0 1 5 0 0 0 0 6 2010 0 0 0 0 1 8 13 8 2 0 0 0 32 2011 0 0 0 0 0 1 10 2 0 0 0 0 13 2012 0 0 0 0 0 5 8 2 1 0 0 0 16 2013 0 0 0 0 0 2 7 0 0 0 0 0 9 2014 0 0 0 0 0 1 0 0 1 0 0 0 2 2015 0 0 0 0 0 1 3 6 2 0 0 0 12 2016 0 0 0 0 0 1 7 6 1 0 0 0 15 2017 0 0 0 0 1 2 5 0 1 0 0 0 9 2018 0 0 0 0 0 1 2 4 1 0 0 0 8 2019 0 0 0 0 0 1 5 0 0 1 0 0 7 2020 0 0 0 0 0 0 10 2 0 0 0 0 12 2021 0 0 0 0 2 3 1 4 - - - - 10

With the recent upgrade to NWS data, one can go here, choose JFK and then “first-last” dates. https://www.weather.gov/wrh/Climate?wfo=okx First-last 90F readings JFK: Date First Last 2000 Jun-10 (2000) Aug-08 (2000) 2001 Jun-27 (2001) Aug-10 (2001) 2002 Apr-17 (2002) Aug-18 (2002) 2003 Jun-24 (2003) Aug-27 (2003) 2004 Jun-09 (2004) Jun-09 (2004) 2005 Jun-14 (2005) Sep-12 (2005) 2006 Jul-02 (2006) Aug-20 (2006) 2007 Jun-17 (2007) Oct-08 (2007) 2008 Jun-08 (2008) Aug-06 (2008) 2009 Jul-30 (2009) Aug-19 (2009) 2010 May-26 (2010) Sep-08 (2010) 2011 Jun-09 (2011) Aug-08 (2011) 2012 Jun-20 (2012) Sep-01 (2012) 2013 Jun-24 (2013) Jul-20 (2013) 2014 Jun-18 (2014) Sep-02 (2014) 2015 Jun-21 (2015) Sep-08 (2015) 2016 Jun-22 (2016) Sep-09 (2016) 2017 May-19 (2017) Sep-24 (2017) 2018 Jun-29 (2018) Sep-04 (2018) 2019 Jun-27 (2019) Oct-02 (2019) 2020 Jul-02 (2020) Aug-27 (2020)

In southern Westchester, it is partly sunny and breezy right now.

In 1858, a hurricane impacted San Diego. Here’s a paper on that storm, which mentions others that have impacted CA and/or AZ: https://www.aoml.noaa.gov/hrd/Landsea/chenowethlandsea.pdf

Morning thoughts… At 7:15 am, rain was continuing to fall in parts of Suffolk County. Flash flooding was reported at Nesconset (1 SE), Saint James (1 S), and Saint James (1 SSE). Islip had also picked up 1.20” of rain in a one-hour period. Today will be mostly cloudy, breezy, and noticeably cooler. Showers and periods of rain are likely. Some areas of heavy rain are possible in parts of the region this morning. High temperatures will likely reach the middle and upper 70s. Likely high temperatures around the region include: New York City (Central Park): 75° Newark: 78° Philadelphia: 79° Normals: New York City: 30-Year: 81.7°; 15-Year: 81.5° Newark: 30-Year: 83.1°; 15-Year: 83.1° Philadelphia: 30-Year: 84.3°; 15-Year: 83.9° Late tomorrow, Hurricane Ida will likely make landfall along the Louisiana coast as a strong Category 4 hurricane. Some of its rains could affect the Middle Atlantic region during the middle of next week.

A front will move slowly through the region and it could stall nearby tonight and tomorrow. The result will be cooler weather with potential showers and thundershowers tonight and tomorrow. Drier air could arrive for Sunday. Looking farther ahead, September will likely feature near normal to somewhat warmer than normal temperatures overall. Meanwhile Tropical Storm Ida has now developed. Ida will pose a threat to the U.S. Gulf Coast late Sunday into Monday. Some of the guidance has it making landfall as a Category 3 or Category 4 hurricane. Through 7 pm CDT, New Orleans has received 65.74" of rain. That is the 2nd highest figure on record for this time of year. As a result, the already saturated ground could exacerbate the risk of flooding from Ida. Fall 2021 will likely be wetter to much wetter than normal in the northern Middle Atlantic region. Since 1869, there have been 9 August cases where New York City picked up 20.00" or more rainfall during the summer. Two thirds of those cases (and 4/5 of those with summer mean temperatures of 73.0° or above) had 17.00" or more fall precipitation in New York City. 2011 is probably the closest match in terms of precipitation and a nearly identical summer mean temperature. Mean fall precipitation for those 9 cases was 14.86". The median was 17.35". The 1991-2020 normal value is 12.27". The ENSO Region 1+2 anomaly was -0.1°C and the Region 3.4 anomaly was -0.9°C for the week centered around August 18. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.41°C and the ENSO Region 3.4 anomaly has averaged -0.43°C. Neutral ENSO conditions will likely prevail into mid-September. Afterward, La Niña could begin to develop. The SOI was +5.95 today. The preliminary Arctic Oscillation (AO) figure was -0.572 today. On August 25 the MJO was in Phase 2 at an amplitude of 0.760 (RMM). The August 24-adjusted amplitude was 0.478 (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 August (1991-2020 normal). August will likely finish with a mean temperature near 77.6° (1.6° above normal).

It will also be interesting to see how Tucson does with Nora’s moisture. July was its wettest month on record.

With 0.66” of rain so far, Central Park has reached 10” rain for August.

I believe that’s it.

No. Dingmans Ferry actually referred to a bridge.

This is true. I go there often, as I have a sister who lives in the Dingmans Ferry area.

Islip hit 93° so far. That broke the daily record of 92°, which was set just last year.

Flood Watch National Weather Service New York NY 1151 AM EDT Fri Aug 27 2021 NYZ069-071>075-176-178-280500- /O.EXA.KOKX.FF.A.0007.210827T1800Z-210829T0600Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Rockland-Southern Westchester-New York (Manhattan)-Bronx- Richmond (Staten Island)-Kings (Brooklyn)-Northern Queens- Southern Queens- 1151 AM EDT Fri Aug 27 2021 ...FLASH FLOOD WATCH IN EFFECT THROUGH LATE SATURDAY NIGHT... The National Weather Service in Upton has expanded the * Flash Flood Watch to include a portion of southeast New York, including the following areas, Bronx, Kings (Brooklyn), New York (Manhattan), Northern Queens, Richmond (Staten Island), Rockland, Southern Queens, and Southern Westchester. * Through late Saturday night * A moist environment could result in heavy rain producing thunderstorms this afternoon into Saturday night. With recent heavy rainfall, it will not take much additional rain to result in flash flooding. The greatest risk looks to be this afternoon through Saturday afternoon. * Rainfall rates of 1 to 2 inches per hour could result in flash flooding, especially in low-lying and poor drainage areas such as highway underpasses. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. &&

Morning thoughts… Today will be partly sunny and hot. The risk of showers and thundershowers will increase during the afternoon and evening. High temperatures will likely reach the upper 80s and lower 90s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 90° Newark: 93° Philadelphia: 92° Normals: New York City: 30-Year: 81.9°; 15-Year: 81.7° Newark: 30-Year: 83.3°; 15-Year: 83.3° Philadelphia: 30-Year: 84.5°; 15-Year: 84.1° A cooler and occasionally wet weekend lies ahead.

One more hot day lies ahead. Afterward, a front will move slowly through the region and it could stall nearby. The result will be cooler weather with potential showers and thundershowers during the weekend. Meanwhile Tropical Storm Ida has now developed. Ida will pose a threat to the U.S. Gulf Coast early next week. Some of the guidance has it making landfall as a Category 2 or Category 3 hurricane. Through 7 pm CDT, New Orleans has received 65.74" of rain. That is the 2nd highest figure on record for this time of year. As a result, the already saturated ground could exacerbate the risk of flooding from Ida. Fall 2021 will likely be wetter to much wetter than normal in the northern Middle Atlantic region. Since 1869, there have been 9 August cases where New York City picked up 20.00" or more rainfall during the summer. Two thirds of those cases (and 4/5 of those with summer mean temperatures of 73.0° or above) had 17.00" or more fall precipitation in New York City. 2011 is probably the closest match in terms of precipitation and a nearly identical summer mean temperature. Mean fall precipitation for those 9 cases was 14.86". The median was 17.35". The 1991-2020 normal value is 12.27". The ENSO Region 1+2 anomaly was -0.1°C and the Region 3.4 anomaly was -0.9°C for the week centered around August 18. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.41°C and the ENSO Region 3.4 anomaly has averaged -0.43°C. Neutral ENSO conditions will likely prevail into mid-September. Afterward, La Niña could begin to develop. The SOI was +5.83 today. The preliminary Arctic Oscillation (AO) figure was -0.640 today. On August 24 the MJO was in Phase 2 at an amplitude of 0.489 (RMM). The August 23-adjusted amplitude was 0.553 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied 96% probability that New York City will have a warmer than normal August (1991-2020 normal). August will likely finish with a mean temperature near 77.4° (1.4° above normal).

New NWS portal: https://www.weather.gov/wrh/climate

Morning thoughts… Today will be partly sunny and hot. High temperatures will likely reach the lower 90s in most of the region with some places topping out in the middle 90s. Likely high temperatures around the region include: New York City (Central Park): 90° Newark: 94° Philadelphia: 92° Normals: New York City: 30-Year: 82.1°; 15-Year: 81.9° Newark: 30-Year: 83.5°; 15-Year: 83.4° Philadelphia: 30-Year: 84.6°; 15-Year: 84.3° The very warm weather will continue through tomorrow before it turns cooler for the weekend.

At present, I still lean toward a miss. Hopefully, that thinking is incorrect. Currently, 23/51 (45%) of EPS members (8/25 12z) show 0.35” or more. That is broadly in line with the historical frequency for the 1971-2020 period. As tomorrow is virtually certain to see no rain, I ran the numbers of the 8/27-8/31 period. 60% of cases had < 0.35” rain. 40% had 0.35” or more (20% had 1.00” or more). The National Blend of Models still does not show enough precipitation.

It is. One study suggested that NYC’s climate could resemble that of present-day Virginia Beach by the end of the 21st century.

Today saw temperatures rise into the lower and middle 90s across much of the region. Tomorrow will be a similar day. 90° Days for Select Cities (through August 25): Albany: 4 (2020: 13 days; 5-Year Average: 13.6 days) Allentown: 22 (2020: 24 days; 5-Year Average: 27.6 days) Baltimore: 46 (2020: 46 days; 5-Year Average: 44.6 days) Boston: 22 (2020: 14 days; 5-Year Average: 17.2 days) Bridgeport: 10 (2020: 11 days; 5-Year Average: 13.4 days) Burlington: 13 (2020: 20 days; 5-Year Average: 13.0 days) Harrisburg: 32 (2020: 35 days; 5-Year Average: 30.6 days) Hartford: 22 (2020: 39 days; 5-Year Average: 29.0 days) Islip: 7 (2020: 8 days; 5-Year Average: 9.4 days) New York City-JFK: 9 (2020: 12 days; 5-Year Average: 10.2 days) New York City-LGA: 23 (2020: 34 days; 5-Year Average: 29.4 days) New York City-NYC: 15 (2020: 20 days; 5-Year Average: 18.2 days) Newark: 37 (2020: 33 days; 5-Year Average: 31.2 days) Philadelphia: 33 (2020: 36 days; 5-Year Average: 34.6 days) Scranton: 17 (2020: 25 days; 5-Year Average: 16.4 days) Washington, DC: 42 (2020: 46 days; 5-Year Average: 50.8 days) New York City-Newark Average: 21 (2020: 22 days) ...Expected: 23 (based on regression equation tied to JFK-LGA-EWR data) Much of the remainder of this week will feature unseasonably warm temperatures. Cooler weather and possibly some rain will arrive for the weekend. Fall 2021 will likely be wetter to much wetter than normal in the northern Middle Atlantic region. Since 1869, there have been 9 August cases where New York City picked up 20.00" or more rainfall during the summer. Two thirds of those cases (and 4/5 of those with summer mean temperatures of 73.0° or above) had 17.00" or more fall precipitation in New York City. 2011 is probably the closest match in terms of precipitation and a nearly identical summer mean temperature. Mean fall precipitation for those 9 cases was 14.86". The median was 17.35". The 1991-2020 normal value is 12.27". The ENSO Region 1+2 anomaly was -0.1°C and the Region 3.4 anomaly was -0.9°C for the week centered around August 18. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.41°C and the ENSO Region 3.4 anomaly has averaged -0.43°C. Neutral ENSO conditions will likely prevail into mid-September. Afterward, La Niña could begin to develop. The SOI was +10.07 today. The preliminary Arctic Oscillation (AO) figure was -0.600 today. On August 23 the MJO was in Phase 2 at an amplitude of 0.586 (RMM). The August 22-adjusted amplitude was 0.672 (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 August (1991-2020 normal). August will likely finish with a mean temperature near 77.3° (1.3° above normal).

For reference, these are the locations at the highest latitude (eastern North America) that I could find that recorded one or more cases where July and August both received 10” or more of rain: Norfolk (36.85N): 2004 July: 10.89”; August: 11.11” 2011 July: 10.89”; August: 10.79” Salisbury, MD (38.36N): 2017 July: 11.31”; August: 12.23” Wallops Island, VA (37.88N): 2004 July: 12.10”; August: 11.18” Note: All of these cases occurred 2000 or later.

The 12z ECMWF is now wetter for Saturday.