donsutherland1

Significant parts of Larchmont are without power. A number of trees have been uprooted or snapped.

Heavy rain is falling in Larchmont.

In the past hour, Philadelphia picked up 1.77" rain. That brings today's total to 3.61" (old record: 2.74", 1915).

That appears to be the case. The wind will likely pick up very quickly over the next hour or two.

In 26 minutes, Philadelphia has picked up 1.17" rain. That brings the daily figure to 3.01". The daily figure surpassed the old record of 2.74", which was set in 1915.

IEMBot PHI @iembot_phi · 20s PHI continues Tornado Warning [tornado: OBSERVED, hail: 0.00 IN] for Atlantic, Cape May [NJ] till 10:15 AM EDT

From Mount Holly: IEMBot PHI @iembot_phi · 3m PHI issues Tornado Warning [tornado: RADAR INDICATED, hail: 0.00 IN] for Atlantic, Cape May [NJ] till 10:15 AM EDT

IEMBot LWX @iembot_lwx · 29m At 7:35 AM EDT, 4 S Chesapeake Beach [Calvert Co, MD] 911 CALL CENTER reports TORNADO. MULTIPLE TREES REPORTED DOWN IN THE WILLOW BEACH COLONY AREA. https://mesonet.agron.iastate.edu/lsr/#LWX/20200

Morning thoughts... Tropical Storm Isaias has continued to accelerate north-northeastward. At 8 am, Isaias was moving toward the NNE at 33 mph. Very heavy rain was falling in parts of the Middle Atlantic region as Isaias was passing near the Chesapeake Bay. Already Washington, DC and Wilmington, DE have set daily rainfall records: Rainfall through 8:20 am: Washington, DC: 1.78" (old record: 1.33", 1974) Wilmington, DE: 2.04" (old record: 2.00", 1915) Conditions in the New York City , northern New Jersey, and southern Connecticut areas will deteriorate this morning. The heaviest rain will remain west of NYC. Winds will increase with gusts reaching 65 mph in places during the early and middle afternoon. A few locations could experience a tornado or waterspout, especially in any intense bands of rain that pass. Conditions will improve rapidly this evening and overnight.

000 WTNT64 KNHC 040316 TCUAT4 Hurricane Isaias Tropical Cyclone Update NWS National Hurricane Center Miami FL AL092020 1115 PM EDT Mon Aug 3 2020 Doppler radar imagery and surface observations indicate that eye of Hurricane Isaias made landfall in southern North Carolina around 1110 PM EDT (0310 UTC) near Ocean Isle Beach, with maximum sustained winds of 85 mph (140 km/h). A weather station at Oak Island, North Carolina, recently reported sustained winds of 76 mph (122 km/h) and a gust to 87 mph (140 km/h). A data buoy near the coast of North Carolina has recently reported a minimum pressure of 988 MB (29.18 inches). SUMMARY OF 1115 PM EDT...0315 UTC...INFORMATION ----------------------------------------------- LOCATION...33.9N 78.4W ABOUT 40 MI...65 KM SSW OF WILMINGTON NORTH CAROLINA MAXIMUM SUSTAINED WINDS...85 MPH...140 KM/H PRESENT MOVEMENT...NNE OR 20 DEGREES AT 22 MPH...35 KM/H MINIMUM CENTRAL PRESSURE...988 MB...29.18 INCHES $$ Forecaster Brown/Zelinsky/Beven

Sustained winds as high as 55 mph with gusts to 70 mph.

Some rainfall amounts from the thunderstorms that moved through the NYC area as of 10 pm: New York City-JFK: 0.13” (52 mph gust); New York City-LGA: 0.35”; New York City-NYC: 0.54”; Newark: 0.34”; Teterboro: 0.20”.

Some areas had wind gusts in excess of 50 mph. JFK recorded one such gust.

EWR has picked up 0.24” rain in a thunderstorm in the last 10 minutes.

Today was another very warm day with readings again reaching the upper 80s and even lower 90s in some parts of the region. However, clouds will be increasing overnight and an increasingly stormy day lies ahead for tomorrow as Isaias advances north-northeastward. At the height of the storm, winds could gust past 65 mph along coastal New Jersey, the south shore of Long Island and the Long Island Sound. A few 70 mph or above gusts are possible. Isaias will bring heavy rainfall as it moves northward across the Chesapeake Bay, through New Jersey and into southern New York State en route to northern New England and then Canada tomorrow into Wednesday. A general 2"-4" rainfall is likely along and west of a line extending from Poughkeepsie to Wilmington, DE. There will likely be an area of 3"-6" rainfall with locally higher amounts in a portion of the region including Baltimore, Philadelphia and Washington, DC. As of 8:30 pm, Washington, DC had picked up 0.40" rain. Select rainfall estimates based on a weighted multi-model blend include: Allentown: 3"-6" Baltimore: 3"-6" Harrisburg: 2"-4" Islip: 0.50"-1.50" New York City: 1”-3” Newark: 2”-4” Philadelphia: 3”-6” Washington, DC: 3”-6” The 12z UKMET was again a wet outlier. Given the storm's forward motion, its solution appears to be unlikely. As a result, it was discounted. Uncertainty for Islip and New York City remains relatively high. 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 -1.1°C and the Region 3.4 anomaly was -0.8°C for the week centered around July 29. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -1.08°C and the ENSO Region 3.4 anomaly has averaged -0.25°C. Neutral-cool conditions will likely into the start of autumn. During the autumn, La Niña conditions could develop. The Region 3.4 anomaly is the lowest such figure in July since 2010. Since weekly recordkeeping commenced in 1990, July 1998 was the only other summer following an El Niño winter that saw a comparably cool Region 3.4 anomaly. Both cases went on to have a very warm September and warmer than normal autumn. They diverged in December with the state of the Arctic Oscillation (AO) making a decisive difference. The SOI was +0.85. Today, the preliminary Arctic Oscillation (AO) figure was -0.088. On August 2, the MJO was in Phase 3 at an amplitude of 0.780 (RMM). The August 1-adjusted amplitude was 0.995. 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.

The period of baroclinic deepening shown on the ECMWF also contributes. It makes landfall on the SC coast with a 992 mb central pressure. The central pressure falls to 987 mb by the time Isaias is over the Chesapeake Bay. It passes just west of NYC with a central pressure of 990 mb.

Morning thoughts... Isaias remains on track to pass through the region later tomorrow into tomorrow night. The guidance has shifted a little to the west overnight, but the general idea of passage over the Chesapeake Bay across New Jersey and then into southern/central New York State still remains reasonable. With some interaction with a trough, the potential exists for a period of baroclinic deepening. This deepening will likely help the fast-moving system retain a measure of its strength as it passes through the region. Rainfall amounts from New York City eastward will likely need to be reduced, based both on Isaias' track and somewhat faster forward motion than had been forecast yesterday. An area of 3"-6" rain still looks reasonable, especially for cities such as Allentown, Baltimore, Philadelphia and Washington, DC. In its wake, the western Atlantic ridge that helped steer it along its inland course will likely result in a rebound of temperatures. The predominantly warmer than normal pattern will continue. No significant cool shots appear likely through at least the first half of August.

Today, temperatures rose into the upper 80s and lower 90s across the region. 90° Days for Select Cities (through August 2): Albany: 13 (2019: 12 days) Allentown: 20 (2019: 24 days) Baltimore: 36 (2019: 59 days) Boston: 8 (2019: 15 days) Burlington: 18 (2019: 8 days) Harrisburg: 26 (2019: 33 days) Islip: 6 (2019: 8 days) New York City-JFK: 10 (2019: 7 days) New York City-LGA: 26 (2019: 26 days) New York City-NYC: 16 (2019: 15 days) Newark: 23 (2019: 28 days) Philadelphia: 28 (2019: 35 days) Washington, DC: 38 (2019: 62 days) New York City-Newark Average: 19 (2019: 19 days) ...Expected: 19 (based on regression equation tied to JFK-LGA-EWR data) Thunderstorms brought excessive rainfall to parts of Pennsylvania today. At Reading, 5.89" rain fell. That smashed the daily record of 2.62", which was set in 1973 and the August daily rainfall mark of 4.52" from August 22, 1888. Parts of that region will be in for additional heavy rainfall from Isaias' passage. Isaias will bring heavy rainfall as it moves northward across the Chesapeake Bay, through New Jersey and into southern New York State en route to northern New England and then Canada Tuesday into Wednesday. A general 2"-4" rainfall is likely along and west of a line extending from Poughkeepsie to Wilmington, DE. There will likely be an area of 3"-6" rainfall with locally higher amounts in a portion of the region including Baltimore, Philadelphia and Washington, DC. Select rainfall estimates based on a weighted multi-model blend include: Allentown: 3"-6" Baltimore: 3"-6" Harrisburg: 2"-4" Islip: 1"-3" New York City: 2”-4” Newark: 2”-4” Philadelphia: 3”-6” Washington, DC: 3”-6” The UKMET remained an outlier with extreme amounts of precipitation in parts of the region and was largely discounted. The 18z GFS diverged from earlier runs with a much drier outcome from Newark and eastward. The current predominantly warmer than normal pattern will likely persist through at least August, paving the way for a solidly warmer than normal summer 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 -0.4°C for the week centered around July 22. 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 -0.18°C. Neutral-cool conditions will likely into the start of autumn. During the autumn, La Niña conditions could develop. The SOI was -4.43. Today, the preliminary Arctic Oscillation (AO) figure was -0.338. On August 1, the MJO was in Phase 3 at an amplitude of 0.938 (RMM). The July 31-adjusted amplitude was 1.055. 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. Finally, on August 1, Arctic sea ice extent was 5.718 million square kilometers (JAXA). That was the lowest figure on record for August 1. The previous record was 5.905 million square kilometers, which was set just last year. Arctic sea ice extent remains well on a trajectory that will take it to a minimum extent below 4.000 million square kilometers for the second consecutive year and third time on record.

Clouds broke for sunshine this afternoon and the temperature soared into the upper 80s. A sea breeze developed late in the afternoon.

Through 10 am, Reading had received 5.89” rain. That broke the daily record of 2.62” from 1973 and the monthly record of 4.52”, which was set on August 22, 1888. It is also Reading’s 4th highest daily rainfall on record. The record is 6.73”, which was set on October 4, 1869.

Morning thoughts... The northern Middle Atlantic region entered August will below to much below normal precipitation. Through August 1, rainfall amounts for select cities were: Allentown: 22.81” (3.41” below normal) Harrisburg: 22.33” (1.52” below normal) New York City: 22.73” (6.23” below normal) Newark: 23.74” (0.98” below normal) Philadelphia: 23.74” (0.91” below normal) Scranton: 19.84” (1.91” below normal) With the exception of New York City’s Central Park, the combination of today’s thunderstorms and Tropical Storm Isaias’ rains will likely erase all of the year-to-date precipitation deficits. Already, in part due to a thunderstorm that brought 0.90” rain in the past hour, nearly half of Allentown’s precipitation deficit as of August 1 has been wiped out. Very heavy rain was currently falling in the vicinity of Easton. The heaviest rains from Isaias will likely impact an area that runs from Washington, DC across eastern Pennsylvania/northwestern New Jersey where 3”-6” rain is likely. East of there, a 2”-4” rainfall is likely. New York City’s Central Park will probably see 1”-3” from Isaias. The 0z UKMET was alone in focusing the heaviest rains from Isaias to the east of that area. Overall, there is good agreement among the guidance as to the general focus of Isaias’ rains. The expansive western Atlantic ridge responsible for Isaias’ track will block most of the cool air from the Plains States from coming eastward. As a result, temperatures will return to mainly above normal levels following Isaias’ departure.

Warmer weather returned today. Temperatures generally topped out in the upper 80s across the region. Following its hottest month on record, LaGuardia Airport topped out at 90° to begin August. Tomorrow, will see a front push northward across the region. Some areas could see strong to possibly severe thunderstorms. Temperatures will again be above normal. Overall, the first week of August will likely be wetter than normal. Rainfall amounts will likely be enhanced as Isaias moves northward across the Chesapeake Bay, out to New Jersey and the northeastward on Tuesday into Wednesday. An area of 3"-6" rainfall with locally higher amounts will exist in a portion of the region. The current predominantly warmer than normal pattern will likely persist through at least August, paving the way for a solidly warmer than normal summer 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 -0.4°C for the week centered around July 22. 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 -0.18°C. Neutral-cool conditions will likely into the start of autumn. During the autumn, La Niña conditions could develop. The SOI was -9.23. Today, the preliminary Arctic Oscillation (AO) figure was -0.645. On July 31, the MJO was in Phase 4 at an amplitude of 1.057 (RMM). The July 30-adjusted amplitude was 1.018. 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.

This afternoon, the clouds broke for sunshine. In response, the temperature rose to 80°. Two photos:

The hot July of 2020 ended on a cool note relative to the heat that the region has been experiencing. New York City finished July with a monthly mean temperature of 80.0°. That was the City's warmest July since 2011 when the temperature averaged 80.2°. There were also 14 days on which the temperature reached 90° or above, which was the most since 2011 when there were also 14. At LaGuardia Airport, July finished with a monthly mean temperature of 82.9°. That surpassed the record of 82.8°from July 2010 that had been that site's hottest month on record. July 2020 also set records for all months with the most 90° or above days (19), 95° or above days (12) and most 80° or above low temperatures (6). Warmer weather will return tomorrow and likely continue through at least the first week of August. The first week of August will likely be wetter than normal across parts of the region. Rainfall amounts could be enhanced as Isaias brings moisture to the region early next week. The current predominantly warmer than normal pattern will likely persist through at least August, paving the way for a solidly warmer than normal summer 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 -0.4°C for the week centered around July 22. 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 -0.18°C. Neutral-cool conditions will likely into the start of autumn. During the autumn, La Niña conditions could develop. The SOI was -16.01. Today, the preliminary Arctic Oscillation (AO) figure was -0.980. On July 30, the MJO was in Phase 3 at an amplitude of 1.017 (RMM). The July 29-adjusted amplitude was 1.101. 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. Based on the latest guidance, including the EPS weekly forecasts and the CFSv2 monthly forecast, August will likely see temperature anomalies of 1°-2° above normal.

The sun is out in southern Westchester County.