donsutherland1

Much warmer weather will push into the Middle Atlantic and southern New England areas tomorrow. Overall, readings will then remain above to much above normal afterward for an extended period of time with some short intervals of cooler readings, one of which will likely be Friday and Saturday. The ENSO Region 1+2 anomaly was -0.6°C and the Region 3.4 anomaly was -0.2°C for the week centered around September 4. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.52°C and the ENSO Region 3.4 anomaly has averaged +0.10°C. Neutral-warm ENSO conditions are in place in Region 3.4 with neutral-cool conditions in place in Region 1+2. There remains uncertainty about the ENSO evolution later this fall. The outcome could have significant winter season implications. The CFSv2 has recently shifted toward a warm-neutral/borderline weak El Niño signal for the winter. The SOI was -11.11 today. Today, the preliminary Arctic Oscillation (AO) figure was +0.278. Since 1950, there have been five prior cases when the AO averaged -0.500 or below in both July and August: 1950, 1958, 1960, 1968, and 2015. The average temperature for September was 69.1° (69.8° after adjusting for ongoing warming) and 58.9° (59.6° adjusted) for September through November in New York City. The 1981-2010 baseline normal figures are 68.0° and 57.5° respectively. The majority of cases saw a warmer than normal September and all cases featured a warmer than normal fall. Therefore, a warmer than normal September and fall appear likely. The potential for autumn 2019 to rank among the 30 warmest cases on record remains on the table. The latest EPS weeklies are hinting that an extended period of above to much above normal readings could prevail after mid-September. It remains plausible that September 2019 could have a mean temperature of 70.0° or above in New York City. On September 9, the MJO was in Phase 5 at an amplitude of 1.629 (RMM). The September 8-adjusted amplitude was 1.492. Based on sensitivity analysis applied to the latest guidance, the implied probability of New York City having a warmer than normal September is approximately 68%. 　

No. The underlying data is publicly available. That wasn’t the issue. The data can be found here: http://www.meteo.psu.edu/holocene/public_html/shared/research/MANNETAL98/

As far as I know, the case never got to the merits of the issue.

I have no issue with the chart itself. It was likely accurate at the time it was made. Today, it is obsolete.

Earlier today, Joe Bastardi tweeted a global temperature chart that ends in 1995. It's unclear whether he recognized when the chart ended. The link to @tan123 brings one to a widely-known climate change denier. https://twitter.com/BigJoeBastardi/status/1171386083051016193 The chart is misleading. The world has continued to warm since then. The 2018 global temperature anomaly was 0.40°C (0.72°F) above the 1995 figure (+0.85°C/1.53°F in 2018 vs. +0.45°C/+0.81°F in 1995). Further, to remove the noise of internal variability, the 30-year moving average in 2018 had increased to +0.57°C (+1.03°F) from +0.16°C (+0.29°F) in 1995. The red line on the bottom chart depicts the 1995 global temperature to help illustrate how things have changed since then. All temperature data is from the GISTEMP data set. Finally, the linear trend line shows an annual increase of +0.021°C (+0.038°F) since 1995. The coefficient of determination is 0.75.

Much warmer weather will push into the Middle Atlantic and southern New England areas by mid-week. Overall, readings will then remain above to much above normal afterward for an extended period of time. Earlier today, the temperature reached a near record 99° in Atlanta. That was the hottest September reading there since September 8, 1941 when the temperature also reached 99°. Today was also Atlanta's 72nd day on which the temperature reached 90° or above. That is tied with 1943 for Atlanta's 11th highest annual figure on record. Records go back to 1879. The ENSO Region 1+2 anomaly was -0.6°C and the Region 3.4 anomaly was -0.2°C for the week centered around September 4. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.52°C and the ENSO Region 3.4 anomaly has averaged +0.10°C. Neutral-warm ENSO conditions are in place in Region 3.4 with neutral-cool conditions in place in Region 1+2. There remains uncertainty about the ENSO evolution later this fall. The outcome could have significant winter season implications. The CFSv2 has recently shifted toward a warm-neutral/borderline weak El Niño signal for the winter. The SOI was -21.51 today. Today, the preliminary Arctic Oscillation (AO) figure was +0.174. Since 1950, there have been five prior cases when the AO averaged -0.500 or below in both July and August: 1950, 1958, 1960, 1968, and 2015. The average temperature for September was 69.1° (69.8° after adjusting for ongoing warming) and 58.9° (59.6° adjusted) for September through November in New York City. The 1981-2010 baseline normal figures are 68.0° and 57.5° respectively. The majority of cases saw a warmer than normal September and all cases featured a warmer than normal fall. Therefore, a warmer than normal September and fall appear likely. The potential for autumn 2019 to rank among the 30 warmest cases on record remains on the table. The latest EPS weeklies are hinting that an extended period of above to much above normal readings could prevail after mid-September. It remains plausible that September 2019 could have a mean temperature of 70.0° or above in New York City. On September 8, the MJO was in Phase 5 at an amplitude of 1.495 (RMM). The September 7-adjusted amplitude was 1.101. Based on sensitivity analysis applied to the latest guidance, the implied probability of New York City having a warmer than normal September is approximately 66%.

In his blog article, Spencer claims, "(And, no, there is no fingerprint of human-caused warming. All global warming, whether natural or human-caused, looks about the same...)" http://www.drroyspencer.com/2019/09/the-faith-component-of-global-warming-predictions/ His understanding is badly dated. The accumulating evidence strongly suggests otherwise. 1. Atmospheric Carbon Dioxide has been rising steadily. 2. No natural factor to explain this outcome has been identified. It does, however, have a strong correlation with greenhouse gas emissions by humanity (not all of which are being absorbed in sinks). https://www.c2es.org/content/international-emissions/ 3. The 13C/12C ratio in the atmosphere has been decreasing. CO2 emissions from the burning of fossil fuels are of the 12C isotope. That declining ratio offers overwhelming evidence that the origin of the rising atmospheric concentration in CO2 is the burning of fossil fuels. https://cdiac.ess-dive.lbl.gov/trends/co2/iso-sio/iso-sio.html?pagewanted=all 4. The climate models best represent recent warming when rising greenhouse gas forcing is included. There has been a decoupling between global temperature trends and natural forcings. That the evidence demonstrates that the burning of fossil fuels is largely responsible for the rising atmospheric concentration of CO2 provides an unmistakable "fingerprint" of the anthropogenic cause of the ongoing warming).

There are two big issues with the above commentary: 1. A 5%-10% probability of tropical storm-force winds in the far southeast portion of Alabama is far from a "most likely be hit (much) harder than anticipated" scenario. 2. Had the President simply acknowledged that he misspoke (an issue that was corrected by BMX in a timely and sufficiently forceful fashion to regain control over sentiment as the Office was being bombarded by calls from worried Alabama residents) or refrained from commenting on the issue, the matter would never have spiraled to its present state. However, he took a different approach and, IMO, the worst possible one.

If politics can be permitted to supplant science when it comes to weather forecasting, it is or should be an open question whether politics will be permitted to displace unfavorable economic data at some future point in time. This is a bad and damaging precedent, not just for the scientists/meteorologists who have been adversely impacted, but for the U.S. public who relies on them.

Right now, the ensembles are not suggesting the kind of severe AO/NAO block that was in place prior to and up to Sandy's dramatic left-turn. That doesn't mean that a tropical cyclone can't threaten part of the East Coast, only that the probability of a Sandy-type scenario is probably a low one given the present guidance.

The current estimated sea level rise is 3.7 mm per year. The full data can be found at: https://www.aviso.altimetry.fr/en/data/products/ocean-indicators-products/mean-sea-level/products-images.html

Post-tropical Dorian is now moving toward the Newfoundland coastline and will be heading out into the north Atlantic. In the Middle Atlantic and southern New England regions, pleasant readings will prevail over the next few days. However, by mid-week, an extended period of warmth will develop, as heat that has been covering the southeast expands northward. In the South, a number of new record high temperatures were tied or set. Its some of that air mass that will eventually expand northward. Records included: New Orleans: 99° (old record: 96°, 1980); Pensacola: 97° (tied record set in 1980); Tallahassee: 98° (tied record set in 1917 and tied in 1925 and 1990); and, Vero Beach, FL: 94° (old record: 93°, 1949, 1977, and 1978). Records were also shattered in parts of Alaska. Records included: Deadhorse: 66° (old record: 63°, 2010); Gulkana: 70° (old record: 69°, 1979); and, Hoonah: 75° (old record: 70°, 2010). The temperature at Hoonah set a new September record, surpassing by one-degree the record that was set on September 1, 2019. In addition, through 4 pm AKD, Utqiagvik (Barrow) had a daily low temperature of 47°. If that figure stands, it would be the highest September minimum temperature on record for that location. The ENSO Region 1+2 anomaly was -0.4°C and the Region 3.4 anomaly was -0.2°C for the week centered around August 28. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.45°C and the ENSO Region 3.4 anomaly has averaged +0.20°C. Neutral-warm ENSO conditions are in place in Region 3.4 with neutral-cool conditions in place in Region 1+2. There remains uncertainty about the ENSO evolution later this fall. The outcome could have significant winter season implications. The CFSv2 has recently shifted toward a warm-neutral/borderline weak El Niño signal for the winter. The SOI was -20.92 today. Today, the preliminary Arctic Oscillation (AO) figure was +0.230. Since 1950, there have been five prior cases when the AO averaged -0.500 or below in both July and August: 1950, 1958, 1960, 1968, and 2015. The average temperature for September was 69.1° (69.8° after adjusting for ongoing warming) and 58.9° (59.6° adjusted) for September through November in New York City. The 1981-2010 baseline normal figures are 68.0° and 57.5° respectively. The majority of cases saw a warmer than normal September and all cases featured a warmer than normal fall. Therefore, a warmer than normal September and fall appear likely. The potential for autumn 2019 to rank among the 30 warmest cases on record remains on the table. The latest EPS weeklies are hinting that an extended period of above to much above normal readings could prevail after mid-September. It remains plausible that September 2019 could have a mean temperature of 70.0° or above in New York City. On September 7, the MJO was in Phase 5 at an amplitude of 1.101 (RMM). The September 6-adjusted amplitude was 1.165. Based on sensitivity analysis applied to the latest guidance, the implied probability of New York City having a warmer than normal September is approximately 63%.

The public information statement concerning Dorian's winds is not official data. Those data and other data will be subject to quality control before any data is finalized. Such quality-controlled figures will be part of the National Hurricane Center's report on Dorian. Because of the unofficial nature of the data, public information statements often carry the following disclaimer or others like it, "The following are unofficial observations taken during the past 24 hours for the storm that has been affecting our region..."

Post-tropical hurricane Dorian continues to pull further away from the region. At 6:15 pm AST, Dorian made landfall near Sambro Creek, Nova Scotia with maximum sustained winds of 100 mph. Tonight and tomorrow, Dorian will likely make landfall at Prince Edward Island and then Newfoundland before heading out into the north Atlantic. In part due to Dorian's vigorous circulation, parts of the region experienced their coolest readings of the season so far earlier today. In New York City, the temperature fell to 56° this morning. That was the lowest temperature since June 13 when the mercury bottomed out at 55°. At Philadelphia, the temperature reached 58°, its coolest figure since June 15 when the minimum temperature was 53°. This early preview of autumn will give way to an extended period of warmth beginning during the middle of next week, as heat that has been building in the southeast expands northward. In the South, a number of new record high temperatures were tied or set. Its some of that air mass that will eventually expand northward. Records included: Charleston, SC: 95° (tied record set in 1941 and tied in 1947); Miami: 94° (tied record set in 2017); New Orleans: 99° (old record: 94°, 1951, 1963, and 1980); Pensacola: 96° (old record: 95°, 1980 and 1990); and Tallahassee: 99° (old record: 98°, 1941 and tied in 1990). In addition, today could be Utqiagvik's (formerly Barrow) 50th day of the year with a low temperature of 40° or above. The old record was 32 days, which was established in 1998. The ENSO Region 1+2 anomaly was -0.4°C and the Region 3.4 anomaly was -0.2°C for the week centered around August 28. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.45°C and the ENSO Region 3.4 anomaly has averaged +0.20°C. Neutral-warm ENSO conditions are in place in Region 3.4 with neutral-cool conditions in place in Region 1+2. There remains uncertainty about the ENSO evolution later this fall. The outcome could have significant winter season implications. The CFSv2 has recently shifted toward a warm-neutral/borderline weak El Niño signal for the winter. The SOI was -15.27 today. Today, the preliminary Arctic Oscillation (AO) figure was +0.225. Since 1950, there have been five prior cases when the AO averaged -0.500 or below in both July and August: 1950, 1958, 1960, 1968, and 2015. The average temperature for September was 69.1° (69.8° after adjusting for ongoing warming) and 58.9° (59.6° adjusted) for September through November in New York City. The 1981-2010 baseline normal figures are 68.0° and 57.5° respectively. The majority of cases saw a warmer than normal September and all cases featured a warmer than normal fall. Therefore, a warmer than normal September and fall appear likely, though the persistence of Dorian's impact on the larger circulation has reduced the probability of a warmer than normal September. Nevertheless, a warm monthly anomaly remains the base case. The potential for autumn 2019 to rank among the 30 warmest cases on record remains on the table. The latest EPS weeklies are hinting that an extended period of above to much above normal readings could prevail after mid-September. On September 6, the MJO was in Phase 5 at an amplitude of 1.154 (RMM). The September 5-adjusted amplitude was 1.228. Based on sensitivity analysis applied to the latest guidance, the implied probability of New York City having a warmer than normal September is approximately 58%.

Extreme heat continued in parts of Colorado today. Pueblo reached 102°, which tied that city's September record, which was set on September 2, 2019. Today was also Pueblo's 3rd 100° day this month. Prior to 2019, Pueblo had only 5 100° or above readings in September. Records go back to 1888. Denver also had a high temperature of 98°, which was just above the daily record of 97° from 1899 and 2013. On September 2, Denver had its first-ever 100° reading in September. Denver has now had 3 high temperatures of 98° or above this month. Prior to 2019, the monthly record had been 97°. Records go back to 1872. A cold front is now moving through the state. Temperatures should be lower tomorrow.

Hurricane Dorian is bringing heavy rain and high winds as it moves ashore in eastern North Carolina. Through 8:30 pm, North Myrtle Beach, NC had picked up 9.98" rain. That is the second highest daily precipitation amount on record for the Myrtle Beach area. Dorian is now starting to accelerate to the northeast. Dorian will likely pass far enough to the east tomorrow into Saturday to avoid having a significant impact on the greater New York City region, though it will very likely lead to rough surf and strong rip currents. Parts of Long Island and eastern New England could still receive some periods of rain or heavier showers and gusty winds associated with Dorian. The storm will likely eventually make landfall in Nova Scotia and then in Newfoundland before racing out into the far northern Atlantic. In the wake of Dorian, the weekend will feature a preview of autumn. Afterward, a return to normal and then above normal temperatures could be slow. Even as Dorian will help usher in a cool air mass in the Northeast, parts of Florida saw near record to record heat following Dorian's offshore passage. High temperatures included: Apalachicola: 97° (tied September record); Pensacola: 99° (highest September temperature since September 25, 1925 when the temperature reached 100°); and, Tallahassee: 99° (highest September temperature since September 19, 2005 when the temperature also hit 100°). The ENSO Region 1+2 anomaly was -0.4°C and the Region 3.4 anomaly was -0.2°C for the week centered around August 28. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.45°C and the ENSO Region 3.4 anomaly has averaged +0.20°C. Neutral-warm ENSO conditions are in place in Region 3.4 with neutral-cool conditions in place in Region 1+2. There remains uncertainty about the ENSO evolution later this fall. The CFSv2 has recently shifted toward a warm-neutral/borderline weak El Niño signal for the winter. The SOI was -12.54 today. Today, the preliminary Arctic Oscillation (AO) figure was +0.832. Since 1950, there have been five prior cases when the AO averaged -0.500 or below in both July and August: 1950, 1958, 1960, 1968, and 2015. The average temperature for September was 69.1° (69.8° after adjusting for ongoing warming) and 58.9° (59.6° adjusted) for September through November in New York City. The 1981-2010 baseline normal figures are 68.0° and 57.5° respectively. The majority of cases saw a warmer than normal September and all cases featured a warmer than normal fall. Therefore, a warmer than normal September and fall appear likely, though the persistence of Dorian's impact on the larger circulation has reduced the probability of a warmer than normal September, though a warm monthly anomaly remains the base case. The potential for autumn 2019 to rank among the 30 warmest cases on record is on the table. On September 4, the MJO was in Phase 5 at an amplitude of 1.151 (RMM). The September 3-adjusted amplitude was 1.079. Based on sensitivity analysis applied to the latest guidance, the implied probability of New York City having a warmer than normal September is near 50%.

Hurricane Dorian is currently bringing rain to portions of the Georgia, South Carolina, and North Carolina. As Dorian moves northeastward across easternmost North Carolina, it will likely bring heavy rain and damaging winds to parts of Georgia, South Carolina, North Carolina and Virginia tonight and tomorrow. Afterward, Dorian will likely pass far enough to the east to avoid having a significant impact on the greater New York City region, though it will very likely lead to rough surf and strong rip currents. Parts of Long Island and eastern New England could still receive some periods of rain or heavier showers and gusty winds associated with Dorian. The storm will likely eventually make landfall in Newfoundland. On account of Dorian's strong circulation, an unseasonably cool air mass could push into the region for the latter part of this week. Beyond that, the timing for a return to normal and then above normal temperatures could be slow. Ahead of a frontal passage, temperatures rose into the 80s and 90s in the Middle Atlantic and southern New England areas. High temperatures included: Baltimore: 96° (tied record set in 1937); Harrisburg: 89°; New York City: 87°; Newark: 90°; Philadelphia: 92°; and, Washington, DC: 96° (old record: 95°, 1985, 2008, and 2018). The ENSO Region 1+2 anomaly was -0.4°C and the Region 3.4 anomaly was -0.2°C for the week centered around August 28. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.45°C and the ENSO Region 3.4 anomaly has averaged +0.20°C. Neutral-warm ENSO conditions are in place in Region 3.4 with neutral-cool conditions in place in Region 1+2. There remains uncertainty about the ENSO evolution later this fall. The CFSv2 has recently shifted toward a warm-neutral/borderline weak El Niño signal for the winter. The SOI was -14.79 today. Today, the preliminary Arctic Oscillation (AO) figure was +0.901. Since 1950, there have been five prior cases when the AO averaged -0.500 or below in both July and August: 1950, 1958, 1960, 1968, and 2015. The average temperature for September was 69.1° (69.8° after adjusting for ongoing warming) and 58.9° (59.6° adjusted) for September through November in New York City. The 1981-2010 baseline normal figures are 68.0° and 57.5° respectively. The majority of cases saw a warmer than normal September and all cases featured a warmer than normal fall. Therefore, a warmer than normal September and fall appear likely, though the persistence of Dorian's impact on the larger circulation has reduced the probability of a warmer than normal September, though a warm monthly anomaly remains the base case. The potential for autumn 2019 to rank among the 30 warmest cases on record is on the table. On September 3, the MJO was in Phase 4 at an amplitude of 1.069 (RMM). The September 2-adjusted amplitude was 1.030. The MJO has now been in Phase 4 for 9 consecutive days. The last time the MJO was in Phase 4 for at least 9 consecutive days was August 20-29, 2018 when the MJO was in Phase 4 for 10 consecutive days. Based on sensitivity analysis applied to the latest guidance, the implied probability of New York City having a warmer than normal September is 51%. 　

Utqiagvik (formerly Barrow) has seen a dramatic increase in the number of days each year where the temperature stays above freezing. Much of the increase has come recently, as summer Arctic sea ice has declined markedly from prior levels. The change in the 30-year moving averages (to remove the noise of interannual variability) for the number of such days provides further illustration of the dramatic warming that is underway in the Arctic region. For the 1961-90 base period, the 30-year moving average was 43.9 days. For the latest 30-year period (1989-2018), the moving average has increased to 63.4 days. That's a nearly 20-day increase over a remarkably short period of time. Through September 3, Utqiagvik has had 76 days with temperatures above freezing. The last time Utqiagvik had fewer than 50 days above freezing was 2003. In 2007, the minimum Arctic sea ice extent fell below 5 million square kilometers for the first time (JAXA data set). Since then, only 2009 has had a minimum extent of 5 million square kilometers (5.054 million square kilometers). As of September 3, Arctic sea ice extent was 4.175 million square kilometers. During the "low ice" era that commenced in 2007, Utquiavik has averaged 76.8 days per year (2007-18) with above freezing temperatures. Through September 3, Utqiagvik had a record 70 consecutive days where the temperature has stayed above freezing. The old record was 68 consecutive days from July 1-September 6, 2009. Prior to 2009, there were no cases with 60 or more consecutive days above freezing.

I included a chart for AO-/EPO- summers (averages are based on all days that met both criteria). That historically warm pattern has also grown warmer.

Dorian has moved slowly away from the Bahamas and is now moving northwestward off the Florida Peninsula. Tomorrow, Dorian will gradually accelerate and eventually add an easterly component to its motion. In addition to Florida's east coast, portions of the Georgia's, South Carolina's, North Carolina's, and Virginia's coastlines will likely experience heavy rain and at least some damaging winds. Coastal flooding is very likely. Afterward, Dorian will likely pass far enough to the east to avoid having a significant impact on the greater New York City region, though it will very likely lead to rough surf and strong rip currents. Parts of Long Island and eastern New England could still receive some periods of rain or heavier showers and gusty winds associated with Dorian. The storm will likely eventually make landfall in Newfoundland. Dorian's principal impact might be the amplification of the larger circulation. As a result, an unseasonably cool air mass could push into the region for the latter part of this week. Beyond that, the timing for a return to normal and then above normal temperatures could be slow. Some of the guidance is signaling a rebound to notably warmer conditions after mid-month. The ENSO Region 1+2 anomaly was -0.4°C and the Region 3.4 anomaly was -0.2°C for the week centered around August 28. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.45°C and the ENSO Region 3.4 anomaly has averaged +0.20°C. Neutral-warm ENSO conditions are in place in Region 3.4 with neutral-cool conditions in place in Region 1+2. There remains uncertainty about the ENSO evolution later this fall. The CFSv2 has recently shifted toward a warm-neutral/borderline weak El Niño signal for the winter. The SOI was -16.70 today. Today, the preliminary Arctic Oscillation (AO) figure was +0.835. Since 1950, there have been five prior cases when the AO averaged -0.500 or below in both July and August: 1950, 1958, 1960, 1968, and 2015. The average temperature for September was 69.1° (69.8° after adjusting for ongoing warming) and 58.9° (59.6° adjusted) for September through November in New York City. The 1981-2010 baseline normal figures are 68.0° and 57.5° respectively. The majority of cases saw a warmer than normal September and all cases featured a warmer than normal fall. Therefore, a warmer than normal September and fall appear likely, though the persistence of Dorian's impact on the larger circulation has reduced the probability of a warmer than normal September, though a warm monthly anomaly remains the base case. The potential for autumn 2019 to rank among the 30 warmest cases on record is on the table. On September 2, the MJO was in Phase 4 at an amplitude of 1.031 (RMM). The September 1-adjusted amplitude was 0.879. Based on sensitivity analysis applied to the latest guidance, the implied probability of New York City having a warmer than normal September is 53%.

Let me rephrase things a little. The pattern was not forecast to be especially unfavorable to ice reduction. The forecast showed fluctuations in the NAM, not a persistent anomaly. One would have needed a fairly extraordinary development to lead to an unprecedented early end to melt season. The MAN had been forecast to slide back toward neutral during the first week of September. All other things being equal, that suggested reductions in Arctic sea ice would continue probably for another week and perhaps two.

As you noted correctly, had there been an August minimum, it would have been unprecedented. Since 8/31, Arctic sea ice extent has continued to decline. That a piece of guidance would suggest an unprecedented situation, moreso when the upper air pattern had been forecast to grow more favorable for continued reductions in sea ice, raises some questions about the model itself. I'm not sure what the track record of the model in question is, but this is a high profile miss. Overall, forecasting of sea ice minimums remains a fairly low skill endeavor at present.

Hurricane Dorian will continue to gradually weaken tonight and tomorrow as continues its slow turn to the north. Nevertheless, Dorian will remain a powerful hurricane. Dorian will likely pass just off the Florida Peninsula. As Dorian comes northward and gradually takes a more eastward turn, portions of the Florida, Georgia, and the Carolinas' coastlines will likely experience heavy rain and at least some damaging winds. Coastal flooding is very likely. Afterward, Dorian will likely pass far enough to the east to avoid having a significant impact on the greater New York City region, though it will very likely lead to rough surf and strong rip currents. Parts of Long Island and eastern New England could still receive some periods of rain or heavier showers and gusty winds associated with Dorian. Dorian's principal impact might be the amplification of the larger circulation. As a result, an unseasonably cool air mass could push into the region for the latter part of this week. Beyond that, the timing for a return to normal and then above normal temperatures could be slow. Some of the guidance is signaling a rebound to notably warmer conditions after mid-month. Across the Atlantic Ocean, the most recent round of excessive heat continues to dissipate in Europe. Nevertheless, as the area of warmth headed north and east, a number of records were set. Select records included: Kecskemet, Hungary: 91°, Kirkenes Lufthavn, Norway: 72° (tied September record); Kruunupyy, Finland: 73°; Murmansk, Russia: 75° (new September record); Oulu, Finland: 75°; Pecs, Hungary: 90°; Rovaniemi, Finland: 72°; Szolnok, Hungary: 91°; and, Vadso, Norway: 68°. In the United States, Denver recorded a 100° high temperature, its latest 100° reading on record. The prior latest such temperature occurred on August 16, 2002. Pueblo, CO also saw the temperature set a new September record at 102°. The ENSO Region 1+2 anomaly was -0.4°C and the Region 3.4 anomaly was -0.2°C for the week centered around August 28. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.45°C and the ENSO Region 3.4 anomaly has averaged +0.20°C. Neutral-warm ENSO conditions are in place in Region 3.4 with neutral-cool conditions in place in Region 1+2. There remains uncertainty about the ENSO evolution later this fall. The CFSv2 has recently shifted toward a warm-neutral/borderline weak El Niño signal for the winter. The SOI was -20.86 today. Today, the preliminary Arctic Oscillation (AO) figure was +0.419. Since 1950, there have been five prior cases when the AO averaged -0.500 or below in both July and August: 1950, 1958, 1960, 1968, and 2015. The average temperature for September was 69.1° (69.8° after adjusting for ongoing warming) and 58.9° (59.6° adjusted) for September through November in New York City. The 1981-2010 baseline normal figures are 68.0° and 57.5° respectively. The majority of cases saw a warmer than normal September and all cases featured a warmer than normal fall. Therefore, a warmer than normal September and fall appear likely, though the persistence of Dorian's impact on the larger circulation has reduced the probability of a warmer than normal September, though a warm monthly anomaly remains the base case. The potential for autumn 2019 to rank among the 30 warmest cases on record is on the table. On September 1, the MJO was in Phase 4 at an amplitude of 0.881 (RMM). The August 31-adjusted amplitude was 1.039. Based on sensitivity analysis applied to the latest guidance, the implied probability of New York City having a warmer than normal September is 48%.

Numerous monthly records were set in Colorado and Wyoming today.

With Hurricane Dorian's historic intensification, it is a good time to point to an article in the American Meteorological Society's Journal of Climate from last fall. The article noted that one can expect more intense storms on account of climate change. Abstract: As one of the first global coupled climate models to simulate and predict category 4 and 5 (Saffir–Simpson scale) tropical cyclones (TCs) and their interannual variations, the High-Resolution Forecast-Oriented Low Ocean Resolution (HiFLOR) model at the Geophysical Fluid Dynamics Laboratory (GFDL) represents a novel source of insight on how the entire TC intensification distribution could be transformed because of climate change. In this study, three 70-yr HiFLOR experiments are performed to identify the effects of climate change on TC intensity and intensification. For each of the experiments, sea surface temperature (SST) is nudged to different climatological targets and atmospheric radiative forcing is specified, allowing us to explore the sensitivity of TCs to these conditions. First, a control experiment, which uses prescribed climatological ocean and radiative forcing based on observations during the years 1986–2005, is compared to two observational records and evaluated for its ability to capture the mean TC behavior during these years. The simulated intensification distributions as well as the percentage of TCs that become major hurricanes show similarities with observations. The control experiment is then compared to two twenty-first-century experiments, in which the climatological SSTs from the control experiment are perturbed by multimodel projected SST anomalies and atmospheric radiative forcing from either 2016–35 or 2081–2100 (RCP4.5 scenario). The frequency, intensity, and intensification distribution of TCs all shift to higher values as the twenty-first century progresses. HiFLOR’s unique response to climate change and fidelity in simulating the present climate lays the groundwork for future studies involving models of this type. The article also covers the likely increase in the most extreme tropical cyclones: The increased probability of higher-intensity TCs becomes more tangible when focusing on the number of TCs that exceed 165 kt in each simulation, which is the fastest wind speed ever recorded during a TC landfall (Typhoon Haiyan; Takagi and Esteban 2016). In the 70-yr HiFLOR CTL experiment, nine TCs achieve awind speed of greater than 165 kt. The number of TCs that exceed this threshold grows to 32 for the 2016–35 simulation and 72 for the 2081–2100 simulation. https://journals.ametsoc.org/doi/10.1175/JCLI-D-17-0898.1