donsutherland1

September concluded with a monthly mean temperature of 69.6°, which was 0.4° above normal. In large part due to the impact former super typhoon Merbok had on altering the jet stream, cool air has covered the northeastern U.S. to close September. Much or all of the first week of October will see generally cooler than normal readings. Rain will arrive tonight. From New York City and its nearby suburbs southward, a general 0.50"-1.50" rainfall with locally higher amounts is likely tomorrow through Sunday. Conditions in ENSO Region 1+2 could have implications for October's temperature anomalies. Since 1950, 15/21 (71%) of cases with an ENSO Region 1+2 anomaly of -0.75°C or below were warmer than normal in the Middle Atlantic region, including Philadelphia and New York City. 48% were 1° or more above average in New York City and 62% were 1° or more above average in Philadelphia. Just 14% were 1° or more below normal in New York City while 24% were 1° or more below normal in Philadelphia. One-third of cases in both cities saw a monthly mean temperature of 60° or above. Such ENSO conditions also favored warmth in the Central and Northern Plains, along with dry conditions in the Plains States. The ENSO Region 1+2 anomaly was -1.0°C and the Region 3.4 anomaly was -0.9°C for the week centered around September 21. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.73°C and the ENSO Region 3.4 anomaly has averaged -0.95°C. La Niña conditions will likely persist through the fall. The SOI was +11.11 today. The preliminary Arctic Oscillation (AO) was +0.451 today. On September 28 the MJO was in Phase 4 at an amplitude of 0.365 (RMM). The September 27-adjusted amplitude was 0.460 (RMM).

DCA _ NYC _ BOS __ ORD _ ATL _ IAH ___ DEN _ PHX _ SEA 0.3 0.4 0.3 1.2 0.2 0.0 1.6 2.2 3.0

This is a great site: https://xmacis.rcc-acis.org

The week will likely end with unseasonably cool temperatures. At least some showers are likely this weekend. Parts of the region, especially central New Jersey southward could see some steadier and perhaps heavier rain. Conditions in ENSO Region 1+2 could have implications for October's temperature anomalies. Since 1950, 15/21 (71%) of cases with an ENSO Region 1+2 anomaly of -0.75°C or below were warmer than normal in the Middle Atlantic region, including Philadelphia and New York City. 48% were 1° or more above average in New York City and 62% were 1° or more above average in Philadelphia. Just 14% were 1° or more below normal in New York City while 24% were 1° or more below normal in Philadelphia. One-third of cases in both cities saw a monthly mean temperature of 60° or above. Such ENSO conditions also favored warmth in the Central and Northern Plains, along with dry conditions in the Plains States. Over the past two days, Orlando has seen a two-day record rainfall of 13.05". As a result, September 2022 is Orlando's wettest month on record with total rainfall of 22.36". Ian will make landfall in South Carolina tomorrow. The ENSO Region 1+2 anomaly was -1.0°C and the Region 3.4 anomaly was -0.9°C for the week centered around September 21. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.73°C and the ENSO Region 3.4 anomaly has averaged -0.95°C. La Niña conditions will likely persist through the fall. The SOI was +16.46 today. The preliminary Arctic Oscillation (AO) was -0.402 today. On September 27 the MJO was in Phase 4 at an amplitude of 0.459 (RMM). The September 26-adjusted amplitude was 0.455 (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 September (1991-2020 normal). September will likely finish with a mean temperature near 69.6° (0.4° above normal).

Morning thoughts… Today will be partly and somewhat cooler. High temperatures will reach the upper 60s and lower 70s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 67° Newark: 69° Philadelphia: 71° The week will end with cool temperatures. Normals: New York City: 30-Year: 71.0°; 15-Year: 72.3° Newark: 30-Year: 72.6°; 15-Year: 74.1° Philadelphia: 30-Year: 73.9°; 15-Year: 75.1°

The week will likely end with unseasonably cool temperatures. At least some showers are likely this weekend. Parts of the region, especially central New Jersey southward could see some steadier and perhaps heavier rain. Conditions in ENSO Region 1+2 could have implications for October's temperature anomalies. Since 1950, 15/21 (71%) of cases with an ENSO Region 1+2 anomaly of -0.75°C or below were warmer than normal in the Middle Atlantic region, including Philadelphia and New York City. 48% were 1° or more above average in New York City and 62% were 1° or more above average in Philadelphia. Just 14% were 1° or more below normal in New York City while 24% were 1° or more below normal in Philadelphia. One-third of cases in both cities saw a monthly mean temperature of 60° or above. Such ENSO conditions also favored warmth in the Central and Northern Plains, along with dry conditions in the Plains States. This afternoon, Hurricane Ian made landfall along Florida's southwest coast with maximum sustained winds of 150 mph. Ian is the 4th hurricane with maximum sustained winds of 150 mph or above to make U.S. landfall during the last 5 years. Michael (2018), Laura (2020), and Ida (2021) are the others. No other five-year period saw so many powerful hurricanes make U.S. landfall. Ian will continue to move across Florida tonight. Heavy rain and high winds will continue to inflict damage. In part due to Merbok's impact on the jet stream, September will likely end with cooler than normal conditions. The cool weather could continue into at least the start of October. In the 6 past cases when the June AO averaged +0.750 or above (1950-2021), 67% of the following August and September cases featured above normal temperatures. The August ECMWF forecast shows a warmer than normal September in the Northeast. This warmth would be consistent with the ongoing warming that has been occurring in September. The ENSO Region 1+2 anomaly was -1.0°C and the Region 3.4 anomaly was -0.9°C for the week centered around September 21. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.73°C and the ENSO Region 3.4 anomaly has averaged -0.95°C. La Niña conditions will likely persist through the fall. The SOI was +25.61 today. The preliminary Arctic Oscillation (AO) was -0.845 today. On September 26 the MJO was in Phase 5 at an amplitude of 0.478 (RMM). The September 25-adjusted amplitude was 0.550 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied 93% probability that New York City will have a warmer than normal September (1991-2020 normal). September will likely finish with a mean temperature near 69.7° (0.5° above normal).

Fort Myers Beach: https://twitter.com/Abbieamerican/status/1575219814922010624?s=20&t=IA_FqLq8-Byq_I-k2s8gJw

Morning thoughts… Today will be partly to mostly sunny and warm. High temperatures will reach the upper 60s and lower 70s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 70° Newark: 72° Philadelphia: 72° The week will end with cool temperatures. Normals: New York City: 30-Year: 71.5°; 15-Year: 72.8° Newark: 30-Year: 73.0°; 15-Year: 74.5° Philadelphia: 30-Year: 74.3°; 15-Year: 75.5° Dangerous and potentially deadly Ian will make Florida landfall tonight.

Cooler air will begin moving into the region tomorrow. The week will likely end with unseasonably cool temperatures. Conditions in ENSO Region 1+2 could have implications for October's temperature anomalies. Since 1950, 15/21 (71%) of cases with an ENSO Region 1+2 anomaly of -0.75°C or below were warmer than normal in the Middle Atlantic region, including Philadelphia and New York City. 48% were 1° or more above average in New York City and 62% were 1° or more above average in Philadelphia. Just 14% were 1° or more below normal in New York City while 24% were 1° or more below normal in Philadelphia. One-third of cases in both cities saw a monthly mean temperature of 60° or above. Such ENSO conditions also favored warmth in the Central and Northern Plains, along with dry conditions in the Plains States. Earlier today, Ian crossed western Cuba with maximum sustained winds of 125 mph. Ian will now move past the Florida Keys and then move toward the Gulf Coast of Florida where it will make landfall. The storm will slow dramatically as it approaches and reaches Florida. As a result, an area of excessive to extreme rainfall is likely. In part due to Merbok's impact on the jet stream, September will likely end with cooler than normal conditions. The cool weather could continue into at least the start of October. In the 6 past cases when the June AO averaged +0.750 or above (1950-2021), 67% of the following August and September cases featured above normal temperatures. The August ECMWF forecast shows a warmer than normal September in the Northeast. This warmth would be consistent with the ongoing warming that has been occurring in September. The ENSO Region 1+2 anomaly was -1.0°C and the Region 3.4 anomaly was -0.9°C for the week centered around September 21. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.73°C and the ENSO Region 3.4 anomaly has averaged -0.95°C. La Niña conditions will likely persist through the fall. The SOI was +35.30 today. That broke the daily record of +30.41 that was set in 1998. The preliminary Arctic Oscillation (AO) was -0.975 today. On September 25 the MJO was in Phase 5 at an amplitude of 0.557 (RMM). The September 24-adjusted amplitude was 0.597 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied 83% probability that New York City will have a warmer than normal September (1991-2020 normal). September will likely finish with a mean temperature near 69.7° (0.5° above normal).

Morning thoughts… Today will be partly to mostly sunny and warm. High temperatures will reach the lower and middle 70s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 73° Newark: 75° Philadelphia: 75° It will turn cooler tomorrow. The week will end with cool temperatures. Normals: New York City: 30-Year: 71.9°; 15-Year: 73.1° Newark: 30-Year: 73.4°; 15-Year: 74.9° Philadelphia: 30-Year: 74.7°; 15-Year: 75.9°

Cooler air will begin moving into the region tomorrow. The week will likely end with unseasonably cool temperatures. Conditions in ENSO Region 1+2 could have implications for October's temperature anomalies. Since 1950, 15/21 (71%) of cases with an ENSO Region 1+2 anomaly of -0.75°C or below were warmer than normal in the Middle Atlantic region, including Philadelphia and New York City. 48% were 1° or more above average in New York City and 62% were 1° or more above average in Philadelphia. Just 14% were 1° or more below normal in New York City while 24% were 1° or more below normal in Philadelphia. One-third of cases in both cities saw a monthly mean temperature of 60° or above. Such ENSO conditions also favored warmth in the Central and Northern Plains, along with dry conditions in the Plains States. Early tomorrow, Cuba will see Ian cross the western end of its island as a major hurricane. Afterward, parts of the Florida Keys and then the Gulf Coast of Florida could face a hurricane threat. Tampa will need to watch the storm carefully. In part due to Merbok's impact on the jet stream, September will likely end with cooler than normal conditions. The cool weather could continue into at least the start of October. In the 6 past cases when the June AO averaged +0.750 or above (1950-2021), 67% of the following August and September cases featured above normal temperatures. The August ECMWF forecast shows a warmer than normal September in the Northeast. This warmth would be consistent with the ongoing warming that has been occurring in September. The ENSO Region 1+2 anomaly was -1.0°C and the Region 3.4 anomaly was -0.9°C for the week centered around September 21. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.73°C and the ENSO Region 3.4 anomaly has averaged -0.95°C. La Niña conditions will likely persist through the fall. The SOI was +32.21 today. That broke the old record of +30.04 from 1998. The preliminary Arctic Oscillation (AO) was -0.686 today. On September 24 the MJO was in Phase 4 at an amplitude of 0.600 (RMM). The September 23-adjusted amplitude was 0.485 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied 78% probability that New York City will have a warmer than normal September (1991-2020 normal). September will likely finish with a mean temperature near 69.7° (0.5° above normal).

Morning thoughts… Today will be partly to mostly sunny and warm. Some scattered showers are possible. High temperatures will reach the lower and middle 70s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 74° Newark: 76° Philadelphia: 77° Tomorrow will be slightly cooler. The week will end with cool temperatures. Normals: New York City: 30-Year: 72.3°; 15-Year: 73.5° Newark: 30-Year: 73.8°; 15-Year: 75.2° Philadelphia: 30-Year: 75.1°; 15-Year: 76.3°

After a few additional showers or thundershowers tonight, tomorrow will be another warm day with temperatures rising to near or somewhat above normal levels. Afterward, cooler air will be bleeding into the region. The week could end with unseasonably cool temperatures. Developments in ENSO Region 1+2 could have implications for October's temperature anomalies. A decline in the anomaly to -1.0°C or below would likely mean a warmer than normal outcome. Since 1950, 11/13 (85%) of cases where the ENSO Region 1+2 anomaly was -1.0°C or below were warmer than normal in the northern Mid-Atlantic region. In New York City, the mean monthly temperature for those cases was 59.3° (the current normal is 57.9°). Of the two cooler cases, 1967 was slightly below normal while 1988 was much cooler than normal. Later this week, Cuba will face a potential major hurricane threat and the Gulf Coast of Florida could face a hurricane threat. In part due to Merbok's impact on the jet stream, September will likely end with cooler than normal conditions. The cool weather could continue into the start of October. In the 6 past cases when the June AO averaged +0.750 or above (1950-2021), 67% of the following August and September cases featured above normal temperatures. The August ECMWF forecast shows a warmer than normal September in the Northeast. This warmth would be consistent with the ongoing warming that has been occurring in September. The ENSO Region 1+2 anomaly was -0.9°C and the Region 3.4 anomaly was -1.0°C for the week centered around September 6. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.62°C and the ENSO Region 3.4 anomaly has averaged -1.00°C. La Niña conditions will likely persist through the fall. The SOI was +24.07 today. The preliminary Arctic Oscillation (AO) was -0.108 today. On September 23 the MJO was in Phase 5 at an amplitude of 0.478 (RMM). The September 22-adjusted amplitude was 0.500 (RMM). 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 September (1991-2020 normal). September will likely finish with a mean temperature near 69.7° (0.5° above normal).

Morning thoughts… Today will be mostly cloudy and warmer. A strong or perhaps severe thunderstorm is possible, especially during the afternoon or evening hours. High temperatures will reach the lower and middle 70s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 73° Newark: 76° Philadelphia: 78° The mild weather will continue tomorrow. Normals: New York City: 30-Year: 72.7°; 15-Year: 73.9° Newark: 30-Year: 74.3°; 15-Year: 75.6° Philadelphia: 30-Year: 75.5°; 15-Year: 76.6°

The surf was lower than had been forecast at Robert Moses, too. The waves had been forecast to be around 10’ but were generally 4’-5’.

This morning, New York City saw the temperature dip into the 40s in September for the first time since September 22, 2020 when the thermometer registered 48°. Early this morning, Hurricane Fiona made landfall in Nova Scotia as a Category 1 hurricane. The storm set a Canadian national low pressure record with a reading of 931.6 mb (27.51") on Hart Island. Next week, Cuba and Florida could face a potential major hurricane threat. Tomorrow and Monday will see readings return to near to somewhat above normal levels. In part due to Merbok's impact on the jet stream, September will likely end with cooler than normal conditions. The cool weather could continue into the start of October. In the 6 past cases when the June AO averaged +0.750 or above (1950-2021), 67% of the following August and September cases featured above normal temperatures. The August ECMWF forecast shows a warmer than normal September in the Northeast. This warmth would be consistent with the ongoing warming that has been occurring in September. The ENSO Region 1+2 anomaly was -0.9°C and the Region 3.4 anomaly was -1.0°C for the week centered around September 6. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.62°C and the ENSO Region 3.4 anomaly has averaged -1.00°C. La Niña conditions will likely persist through the fall. The SOI was +17.06 today. The preliminary Arctic Oscillation (AO) was -0.217 today. On September 22 the MJO was in Phase 3 at an amplitude of 0.482 (RMM). The September 21-adjusted amplitude was 0.478 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied 75% probability that New York City will have a warmer than normal September (1991-2020 normal). September will likely finish with a mean temperature near 69.9° (0.7° above normal).

Some scenes from Robert Moses State Park this morning with waves rolling in from Hurricane Fiona, which made landfall in Nova Scotia very early this morning.

It used to be common. Not any more. This morrning’s low, so far, has been 49.

Morning thoughts… This morning, the temperature fell into the 40s in New York City for the first such September reading since September 22, 2020. Today will be mostly sunny and milder. High temperatures will reach the upper 60s and lower 70s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 70° Newark: 72° Philadelphia: 73° Tomorrow will be warmer. Normals: New York City: 30-Year: 73.1°; 15-Year: 74.3° Newark: 30-Year: 74.7°; 15-Year: 76.0° Philadelphia: 30-Year: 75.9°; 15-Year: 77.0°

I believe Environment Canada issued those warnings. https://www.canada.ca/en/environment-climate-change/services/hurricane-forecasts-facts.html

There’s a real chance. I suspect that Fiona’s expanding circulation will help drive cool air into the region. 40s in September have become infrequent. Since 2000, only 2006, 2009, 2013, and 2020 have seen the temperature dip below 50.

In many parts of the region, today was the coolest day since late Spring. In New York City's Central Park, the mercury topped out at 63°. The last time the high temperature was at least as cool was May 8th when the temperature reached 58°. Newark's high temperature of 64° was the lowest since May 8th when the high was just 62°. Select low temperatures from this morning included: Boston: 50° (coolest since May 26: 50°) New York City: 51° (coolest since May 10: 51°) Newark: 50° (coolest since May 10: 50°) Philadelphia: 56° (coolest since May 26: 54°) After another very cool start, tomorrow will be somewhat warmer with readings reaching the upper 60s and lower 70s. Sunday and Monday will see readings return to near to somewhat above normal levels. In part due to Merbok's impact on the jet stream, September will likely end with cooler than normal conditions. The cool weather could continue into the start of October. In southern Florida, near record and record heat prevailed. Miami reached 95°, which broke the daily mark of 94° from 1943. Today's 95° temperature was the second latest on record. It was also the second such temperature in September, which tied the monthly record set in 1989 and tied in 2019 and 2021. Florida faces a hurricane risk next week. Hurricane Fiona will make landfall in Atlantic Canada tomorrow. With a contribution from the ongoing marine heatwave, Fiona will likely do so as a category 2 hurricane. Canada's lowest barometric pressure on record could be challenged. The powerful storm could also sweep a surge of warm air northward along Greenland's west coast sending temperatures in some areas up to near 50°. In the 6 past cases when the June AO averaged +0.750 or above (1950-2021), 67% of the following August and September cases featured above normal temperatures. The August ECMWF forecast shows a warmer than normal September in the Northeast. This warmth would be consistent with the ongoing warming that has been occurring in September. The ENSO Region 1+2 anomaly was -0.9°C and the Region 3.4 anomaly was -1.0°C for the week centered around September 6. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.62°C and the ENSO Region 3.4 anomaly has averaged -1.00°C. La Niña conditions will likely persist through the fall. The SOI was +14.80 today. The preliminary Arctic Oscillation (AO) was +0.341 today. On September 21 the MJO was in Phase 3 at an amplitude of 0.476 (RMM). The September 20-adjusted amplitude was 0.336 (RMM). 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 September (1991-2020 normal). September will likely finish with a mean temperature near 69.9° (0.7° above normal).

Almost certainly, the ongoing marine heatwave has put a category 3 scenario on the table for Nova Scotia. Without it, one would see a weaker but still potent storm.

Morning thoughts… Today sunny but unseasonably cool. High temperatures will reach the middle 60s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 64° Newark: 66° Philadelphia: 67° Tomorrow will be another cool day. Normals: New York City: 30-Year: 73.5°; 15-Year: 74.7° Newark: 30-Year: 75.1°; 15-Year: 76.3° Philadelphia: 30-Year: 76.3°; 15-Year: 77.4°

Through September 22, Galveston has 100 days on which the low temperature was 80°F or above. That is well above the old mark of 91 days, which was set in 2011. Very few locations in the mainland U.S. have ever seen 100 or more such days.