donsutherland1

Cut Bank fell to 1° yesterday.

Today saw more historic heat across parts of the South. For the first time on record, Birmingham's annual maximum temperature was recorded in October. Tuscaloosa's 101° figure tied the high temperature of 9/13 for the year's hottest reading. Select records (and the list is not all-inclusive): Athens, GA: 98°(tied October record) Atlanta: 96° (new October record) Baltimore: 98° (new October record) ***59th 90° day ties record set in 2010*** Birmingham, AL: 103° (new October record) ***first annual high temperature in October; records go back to 1895; previous latest such temperature 9/9 in 1925*** Charlotte: 99° (new October record) Huntsville, AL: 100° (new October record) Lexington, KY: 96° Louisville: 96° Macon, GA: 98° Mobile, AL: 96° Montgomery, AL: 99° Nashville: 99° (new October record) Norfolk: 97° (new October record) Pensacola: 93° Raleigh: 96° Richmond: 98° Sterling, VA: 96° (new October record) Tuscaloosa, AL: 101°(new October record) ***tied the 9/13/2019 reading for the hottest this year; first October entry in the record book; records go back to 1948*** Washington, DC: 98° (new October record) Distribution of Birmingham's Highest Annual Temperature by Month (1895-2019) May: 3 (2.1%) June: 28 (19.3%) July: 53 (36.6%) August: 43 (29.7%) September: 17 (11.7%) October: 1 (0.7%) Note: The numbers add up to more than the 125-year record, because some years saw the highest annual temperature occur in more than one month.

Much of the region experienced its hottest October day on record. Records included: Allentown: 93° (new October record) Athens, GA: 98°(tied October record) Atlanta: 96° (new October record) Baltimore: 98° (new October record) ***59th 90° day ties record set in 2010*** Birmingham, AL: 103° (new October record) ***first annual high temperature in October; records go back to 1895*** Bridgeport: 87° Charlotte: 99° (new October record) Harrisburg: 93° Huntsville, AL: 100° (new October record) Islip: 89° (new October record) Lexington, KY: 96° Louisville: 96° Macon, GA: 98° Mobile, AL: 96° Montgomery, AL: 99° Nashville: 99° (new October record) New York City-Central Park: 93° New York City-JFK: 95° (new October record) New York City-LGA: 95° (new October record) Newark: 96° (new October record) Norfolk: 97° (new October record) Pensacola: 93° Philadelphia: 95° Poughkeepsie: 88° Raleigh: 96° Richmond: 98° Sterling, VA: 96° (new October record) Tuscaloosa, AL: 101°(new October record) Washington, DC: 98° (new October record) White Plains, NY: 90° (new October record) Wilmington, DE: 98° (new October record) Much cooler air is now pushing into the region. Tomorrow will likely see temperatures struggling to reach 60°. Overall, a 7-10 day period with readings generally near or below normal lies ahead. The ENSO Region 1+2 anomaly was -0.5°C and the Region 3.4 anomaly was +0.5°C for the week centered around September 25. 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 -0.07°C. The recent strong cooling in Region 1+2 indicates that the prospects for a neutral-cool ENSO during the winter have continued to increase. Since 1991 when weekly ENSO region data was available, five years have seen September record 2 or more weeks with -1.0°C or cooler weekly anomalies in Region 1+2: 1996, 1999, 2007, 2010, and 2017. 4/5 (80%) of those cases went on to feature warm December-February temperature anomalies in the Middle Atlantic and southern New England regions. Those cases include La Niña winters. However, the larger pool of neutral-cool ENSO winters, many of which predate the weekly ENSO regional data, have often featured frequent Atlantic blocking. For now, there is a mixed winter signal. The SOI was -11.93 today. Today, the preliminary Arctic Oscillation (AO) figure was -0.443. 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 through November in New York City was 58.9° (59.6° adjusted). All cases featured a warmer than normal fall. The potential for autumn 2019 to rank among the 30 warmest cases on record has increased in recent weeks. For New York City, that would translate into a September-November mean temperature of at least 58.8°. Events during September, including the SOI's falling to -35.30 on September 19, the MJO's being in Phase 1 at an amplitude of 2.000 or above during the September 20-30 period for more than two days, the historic late September snowfall in Great Falls, MT, and the possible ongoing evolution toward a generally positive AO regime, favor a warmer than normal October based on past outcomes. On October 1, the MJO was in Phase 1 at an amplitude of 1.766 (RMM). The September 30-adjusted amplitude was 1.909. Based on sensitivity analysis applied to the latest guidance, the implied probability of New York City having a warmer than normal October is approximately 58%.

Record highs around NYC included: Bridgeport: 87° Islip: 89° (new October record) New York City-Central Park: 93° New York City-JFK: 95° (new October record) New York City-LGA: 95° (new October record) Newark: 96° (new October record) White Plains: 90° (new October record)

JFK had a 4 pm temperature of 94°.

Yes. This is an extremely impressive outbreak of heat.

In parts of the South, monthly record high temperatures were shattered. Monthly records included: Birmingham: 99° (previous October record: 94°, 10/1/1919, 10/5/1927, and 10/6/1954) Chattanooga, TN: 97° (previous October record: 94°, 10/5/1954) Huntsville, AL: 99° (previous October record: 96°, 10/8/1911) Lexington, KY: 97° (previous October record: 93°, 10/6/1941) Louisville: 96° (previous October record: 93°, 10/7-8/2007) Mobile: 97° (previous October record:95°, 10/2/1904) Montgomery, AL: 101° (previous October record: 100°, 10/6/1954) Nashville: 98° (previous October record: 95°, 10/1/1953, 10/5/1954, and 10/8/2007) Pensacola: 96° (previous October record: 95°, 10/8/1884 and 10/5/1951)

Today was a day of records in many parts of the United States. In the wake of a historic late September snowstorm, record low temperatures were recorded in parts of Montana. Records included: Cut Bank: 1°(old record: 14°, 1950) Great Falls: 9° (old record: 22°, 1959) In parts of the East, monthly record high temperatures were shattered. Monthly records included: Akron: 91° (previous October record: 89°, 10/1/1927 and 10/5/1922) Birmingham: 99° (previous October record: 94°, 10/1/1919, 10/5/1927, and 10/6/1954) Cleveland: 93° (previous October record: 90°, 10/6/1946) Huntsville, AL: 99° (previous October record: 96°, 10/8/1911) Lexington, KY: 97° (previous October record: 93°, 10/6/1941) Louisville: 96° (previous October record: 93°, 10/7-8/2007) Nashville: 98° (previous October record: 95°, 10/1/1953, 10/5/1954, and 10/8/2007) Pensacola: 96° (previous October record: 95°, 10/8/1884 and 10/5/1951) Some of this warmth will push into the Mid-Atlantic region tomorrow. Temperatures will likely reach the middle and upper 80s into parts of southern New England. Locations, including Washington, Baltimore, Philadelphia, Newark, and possibly even New York City could reach 90°. The last October 90° or above temperature for select locations occurred on the following dates: Baltimore: October 15, 2015, 90° New York City-Central Park: October 6, 1941, 90° New York City-JFK Airport: October 8, 2007, 90° New York City-LaGuardia Airport: October 6, 1946, 90° Newark: October 6, 1959: 91° Philadelphia: October 7, 1941: 93° Washington, DC: October 4, 2018, 90° Afterward, a period of cooler than normal readings will move into the region during the latter part of the first week of October. This pattern could last 7-10 days, though not every day will be cooler than normal. 　 The ENSO Region 1+2 anomaly was -0.5°C and the Region 3.4 anomaly was +0.5°C for the week centered around September 25. 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 -0.07°C. The recent strong cooling in Region 1+2 indicates that the prospects for a neutral-cool ENSO during the winter have continued to increase. Since 1991 when weekly ENSO region data was available, five years have seen September record 2 or more weeks with -1.0°C or cooler weekly anomalies in Region 1+2: 1996, 1999, 2007, 2010, and 2017. 4/5 (80%) of those cases went on to feature warm December-February temperature anomalies in the Middle Atlantic and southern New England regions. Those cases include La Niña winters. However, the larger pool of neutral-cool ENSO winters, many of which predate the weekly ENSO regional data, have often featured frequent Atlantic blocking. For now, there is a mixed winter signal. The SOI was +2.32 today. Today, the preliminary Arctic Oscillation (AO) figure was not available. 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 through November in New York City was 58.9° (59.6° adjusted). All cases featured a warmer than normal fall. The potential for autumn 2019 to rank among the 30 warmest cases on record has increased in recent weeks. For New York City, that would translate into a September-November mean temperature of at least 58.8°. Events during September, including the SOI's falling to -35.30 on September 19, the MJO's being in Phase 1 at an amplitude of 2.000 or above during the September 20-30 period for more than two days, the historic late September snowfall in Great Falls, MT, and the possible ongoing evolution toward a generally positive AO regime, favor a warmer than normal October based on past outcomes. On September 30, the MJO was in Phase 1 at an amplitude of 1.909 (RMM). The September 29-adjusted amplitude was 2.041. Based on sensitivity analysis applied to the latest guidance, the implied probability of New York City having a warmer than normal October is approximately 60%.

Charlotte concluded its fourth warmest September on record with a mean temperature of 78.7°. Only 1921 (79.2°), 1925 (80.5°), and 2018 (78.8°) were warmer. During the September 16-30 period, Charlotte had a mean temperature of 76.8°, which was tied with 1895 and 1921 for the third warmest such period. The record is 77.1°, which was set during September 16-30, 1925 and tied during September 16-30, 2018. During September 2019, Charlotte reached 90° or above on 21 days, which tied the record set in 1925. During the September 16-30 period, there were 9 days with temperatures of 90° or above. That tied the record, which was set in 1895 and tied in 1931 and 2010. Charlotte has experienced a recent increase in the frequency of 90° or warmer days during September in recent years. The last 10 years (2010-19) averaged 8.8 days with high temperatures of 90° or above. That is the highest figure on record. The highest 10-year average prior to 2000 was 8.7 days during the 1925-34 period. The 30-year moving average (1990-2019) is 5.1 days. That is below the record figure of 6.8 days, which was set during the 1925-54 period. During the September 16-30 period, Charlotte has averaged 2.7 90° or warmer days over the latest 10-year period. That is somewhat below the record of 3.0 days, which was set during the 1925-34 period. The 30-year moving average is currently 1.6 days. The existing record is 2.1 days, which was set during the 1925-54 period and tied during the 1926-55 period. Overall, the average September temperature has been increasing. However, the current 10- and 30-year periods have not attained the warmth seen earlier in Charlotte’s climate record for month as a whole. The last 10 years were tied for the warmest 10-year period during September 16-30. September Mean Temperature: 2010-19: 74.3°; Record: 74.8°, 1925-34 1990-2019: 72.7°; Record: 73.5°, 1918-47 September 16-30 Mean Temperature: 2010-19: 72.6° (tied with 1925-34) 1990-2019: 70.5; Record: 71.1°, 1919-48 Record Temperatures for September 2019: Record High Minimum Temperatures: 9/5/ 74° (tied record set in 1880 and tied in 1921 and 1941) 9/13 73° (tied record set in 2018) 9/14 72° (tied record set in 1915 and tied in 1925, 1938, and 2018) Record High Maximum Temperatures: 9/12 98° (old record: 95°, 1925) 9/26 95° (old record: 94°, 1961) 9/27 94° (old record: 93°, 1900) 9/29 96° (old record: 93°, 1941) 9/30 91° (tied record set in 1926) Finally, through October 1, Charlotte has had 82 days on which the temperature reached 90° or higher. Only 1925 (85 days), 1954 (88 days), and 2010 (87 days) had more.

I will get that info. and post it a little later today.

At 1 pm, the temperature was 91° in Cleveland. That set a new October high temperature record. The previous monthly record was 90°, which was set on October 6, 1946.

Additional temperature data from Georgia: September 2019 Mean Temperatures: Athens: 79.3° (6th) Atlanta: 82.4° (2nd) Augusta: 80.2° (5th) Columbus: 83.3° (3rd) Macon: 81.1° (4th) Savannah: 81.3° (5th) September 16-30, 2019 Mean Temperatures: Athens: 77.3° (7th) Atlanta: 80.6° (2nd) Augusta: 78.2° (12th) Columbus: 82.4° (3rd) Macon: 79.9° (4th) Savannah: 79.9° (7th) Start of Records: Athens: 1902 Atlanta: 1879 Augusta: 1874 Columbus: 1902 Macon: 1897 Savannah: 1874

Atlanta concluded its second warmest September on record with a mean temperature of 82.4°. Only September 1925 with a mean temperature of 83.0° was warmer. During the September 16-30 period, Atlanta had a mean temperature of 80.6°. Only 1925 was warmer during the second half of September with a mean temperature of 80.7°. During September 2019, Atlanta reached 90° or above on 23 days, which tied the record set in 1925. During the September 16-30 period, there were 10 days with temperatures of 90° or above, which broke the previous record of 9, which was set in 1921 and tied in 1925 and 1931. Atlanta has been experiencing an increasing frequency of 90° or warmer days during September. The last 10 years (2010-19) averaged 9.3 days with high temperatures of 90° or above. That is the highest figure on record. The pre-2000 record was 8.0 days during the 1936-45 period. The 30-year moving average (1990-2019) is 5.1 days. That is below the record figure of 6.7 days, which was set during the 1925-54 period. During the September 16-30 period, Atlanta has averaged 3.1 90° or warmer days over the latest 10-year period. That is the highest figure on record. The pre-2000 record was 2.6 days, which was set during the 1924-33 period and tied during the 1925-34 period. The 30-year moving average is currently 1.5 days. The existing record is 2.0 days, which was set during the 1920-49 period and tied during the 1921-50 period. Overall, the average September temperature has been increasing. The current 10- and 30-year periods are the warmest on record for both the month as a whole and for the September 16-30 period. September Mean Temperature: 2010-19: 76.5° (warmest 10-year period on record); pre-2000 record: 75.4°, 1925-34 1990-2019: 74.7° (warmest 30-year period on record); pre-2000 record: 74.3°, 1919-48 September 16-30 Mean Temperature: 2010-19: 75.2° (warmest 10-year period on record); pre-2000 record: 73.1°, 1925-34 1990-2019: 72.0° (warmest 30-year period on record); pre-2000 record: 71.8°, 1929-58 and 1930-59 Record Temperatures for September 2019: Record High Minimum Temperatures: 9/24 73° (tied record set in 1931 and tied in 1980) 9/26 73° (old record: 72°, 2018) 9/27 76° (old record: 73°, 1911) *** highest minimum temperature this late in the season*** 9/29 73° (old record: 72°, 1904) 9/30 74° (tied record set in 1904) Record High Maximum Temperatures: 9/10 98° (old record: 97°, 1925) 9/11 96° (tied record set in 2010) 9/12 99° (old record: 94°, 1900) 9/13 98° (old record: 95°, 1991) 9/17 98° (old record: 97°, 1927) 9/25 93° (tied record set in 2010) 9/26 95° (old record: 90°, 1911 and 1986) 9/27 97° (old record: 93°, 1954) ***highest maximum temperature this late in the season*** 9/29 93° (old record: 92°, 1904 and 1941) 9/30 96° (old record: 91°, 1941) ***highest maximum temperature this late in the season*** Finally, through September 30, Atlanta has had 87 days on which the temperature reached 90° or higher. Only 1980 (90 days), 2011 (90 days), and 2016 (88 days) had more.

A warm September concluded today. 2019 marked the fifth consecutive year during which September had a mean temperature of 70° or above in New York City. In the New York City area, September has increasingly become an extension of summer. Prior to 2000, a monthly mean temperature of 70° or above was relatively uncommon. Prior to 1950, Central Park saw such warmth about once every 5.4 years. From 1950-1999 (during which New York City has had a mature urban footprint), such warmth was recorded approximately once every 4.5 years. Since 2000, 70° Septembers have occurred about once every 2.0 years. There have been 10 such Septembers during the 2000-2019 period, which is just below the figure of 11 recorded during 1950-1999. Since 2010, New York City has had 7 cases where September had a mean temperature of 70° or above, including the last four years. During the last 30 years, September has had a mean temperature of 69.0 degrees, which is the warmest 30-year period on record for September. During the last 10 years, September has had a mean temperature of 70.5 degrees, which is the warmest 10-year period on record for that month. Records go back to 1869. The 1981-2010 normal temperature for September is 68.0°. A dramatic warmup will tomorrow. The heat will likely peak on October 2 with readings in the middle and upper 80s into southern New England. Locations, including Washington, Baltimore, Philadelphia, Newark, and possibly even New York City could reach 90°. Afterward, a period of cooler than normal readings will move into the region during the latter part of the first week of October. This pattern could last 7-10 days, though not every day will be cooler than normal. Events during September, including the SOI's falling to -35.30 on September 19, the MJO's being in Phase 1 at an amplitude of 2.000 or above during the September 20-30 period for more than two days, the historic late September snowfall in Great Falls, MT, and the possible ongoing evolution toward a generally positive AO regime, favor a warmer than normal October based on past outcomes. However, recent guidance has increased uncertainty regarded to the AO's longer-term evolution. That situation bears watching, but the base case remains a warmer than normal October. The historic September Northern Rockies snowstorm had dumped among the following snowfall amounts: Babb, MT: 52.0"; Browning, MT: 48.0"; Great Falls, MT: 19.3"; and, St. Mary, MT: 45.0". Utqiagvik (formerly Barrow) recorded its warmest September on record with its first 40.0° mean temperature for September. The preliminary monthly average was 40.8°. A 40.8° mean temperature was so warm that it ranked as the 27th warmest August and also the 35th warmest July out of 99 years on record. The previous monthly record of 37.7° has stood since 1998. The ENSO Region 1+2 anomaly was -0.5°C and the Region 3.4 anomaly was +0.5°C for the week centered around September 25. 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 -0.07°C. The recent strong cooling in Region 1+2 indicates that the prospects for a neutral-cool ENSO during the winter have continued to increase. Such a scenario is now more likely than not. Since 1991 when weekly ENSO region data was available, five years have seen September record 2 or more weeks with -1.0°C or cooler weekly anomalies in Region 1+2: 1996, 1999, 2007, 2010, and 2017. 4/5 (80%) of those cases went on to feature warm December-February temperature anomalies in the Middle Atlantic and southern New England regions. Those cases include La Niña winters. However, the larger pool of neutral-cool ENSO winters, many of which predate the weekly ENSO regional data, have often featured frequent Atlantic blocking. For now, there is a mixed winter signal. The SOI was +8.20 today. Today, the preliminary Arctic Oscillation (AO) figure was -0.375. 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. New York City finished September with a mean temperature of 70.4°. 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. Following September's warmth, a warmer than normal October lies ahead. The potential for autumn 2019 to rank among the 30 warmest cases on record has increased in recent weeks. For New York City, that would translate into a September-November mean temperature of at least 58.8°. On September 29, the MJO was in Phase 1 at an amplitude of 2.044 (RMM). The September 28-adjusted amplitude was 2.331. Based on sensitivity analysis applied to the latest guidance, the implied probability of New York City having a warmer than normal October is approximately 60%. That is an exceptionally high probability for such an outcome just before the start of the month.

I posted the following last night: " A historic early-season snowfall brought additional snow to Great Falls today following yesterday's September daily record snowfall of 9.7". So far, Browning, MT had picked up 40" snow."

DCA _ NYC _ BOS __ ORD _ ATL _ IAH ___ DEN _ PHX _ SEA 2.4 2.2 1.4 0.5 3.0 1.3 0.4 0.7 -1.0

At least some research shows that at least parts of the Arctic today are the warmest in at least the last 44,000 years. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2013GL057188

Following a brief push of cooler air for tomorrow, there is potential for much above normal warmth to start October. The heat will likely peak on October 2 with readings in the middle and upper 80s into southern New England. Locations, including Washington, Baltimore, Philadelphia, Newark, and possibly even New York City could reach 90°. The PNA is forecast to plunge over the next two days. Typically, a strongly negative PNA (-1.50 or below) during the October 1-3 period has translated into readings averaging 2°-4° above normal in the Middle Atlantic and southern New England regions. The warmth has been even more pronounced when the strongly negative PNA has coincided with a negative SOI. Afterward, a period of cooler than normal readings will move into the region during the latter part of the first week of October. This pattern could last 7-10 days. A historic early-season snowfall brought additional snow to Great Falls today following yesterday's September daily record snowfall of 9.7". So far, Browning, MT had picked up 40" snow. 4" or more snowfalls during the September 20-30 period in Great Falls have been followed by warmer than normal Octobers in the Middle Atlantic region in 5 of 7 (71%) cases. The last three (1941, 1954, and 1984) saw a mean temperature above 60.0° in New York City. The late September pattern provides perhaps another indication that a warmer than normal October lies ahead. Events during September, including the SOI's falling to -35.30 on September 19, the MJO's being in Phase 1 at an amplitude of 2.000 or above during the September 20-30 period for more than two days, and the possible ongoing evolution toward a generally positive AO regime, favor a warmer than normal October based on past outcomes. However, recent guidance has increased uncertainty regarded to the AO's longer-term evolution. That situation bears watching, but the base case remains a warmer than normal October. Courtesy of low sea ice, there is a near 100% implied probability that Utqiagvik (formerly Barrow) will record its warmest September on record. It is very likely that Utqiagvik will register its first 40.0° mean temperature for September with an average temperature near 40.7°. A 40.7° mean temperature would we so warm that it would rank as the 27th warmest August and also the 37th warmest July out of 99 years on record. The existing monthly record of 37.7° has stood since 1998. The ENSO Region 1+2 anomaly was -1.3°C and the Region 3.4 anomaly was -0.2°C for the week centered around September 18. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.77°C and the ENSO Region 3.4 anomaly has averaged -0.16°C. The recent strong cooling in Region 1+2 indicates that the prospects for a neutral-cool ENSO during the winter have continued to increase. Such a scenario is now more likely than not. Since 1991 when weekly ENSO region data was available, five years have seen September record 2 or more weeks with -1.0°C or cooler weekly anomalies in Region 1+2: 1996, 1999, 2007, 2010, and 2017. 4/5 (80%) of those cases went on to feature warm December-February temperature anomalies in the Middle Atlantic and southern New England regions. Those cases include La Niña winters. However, the larger pool of neutral-cool ENSO winters, many of which predate the weekly ENSO regional data, have often featured frequent Atlantic blocking. For now, there is a mixed winter signal. The SOI was +0.95 today. Today, the preliminary Arctic Oscillation (AO) figure was -0.521. 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. A warmer than normal September is now all but certain. A warmer than normal fall remains likely. The potential for autumn 2019 to rank among the 30 warmest cases on record has increased in recent weeks. For New York City, that would translate into a September-November mean temperature of at least 58.8°. On September 28, the MJO was in Phase 1 at an amplitude of 2.275 (RMM). The September 27-adjusted amplitude was 2.473. Based on sensitivity analysis applied to the latest guidance, the implied probability of New York City having a warmer than normal September is near 100% and the probability of a monthly mean temperature of 70.0° or above is 82%. Should September 2019 have a mean temperature of 70.0° or above, 2019 would be the 5th consecutive year with such September warmth. Prior to the current stretch, the record was 2 consecutive years (1930 and 1931; 1970 and 1971; 1979 and 1980; and, 2010 and 2011).

Interestingly enough, 1941 (historic October heat in NYC) and 1954 (record high temperatures on October 12-13 NYC) showed up in the list of late September daily snowfall records. That provides possible insight into at least the near-term pattern and adds confidence to the idea of the very temperatures likely to start the month.

NASA Goddard Space Flight Center video on this year's Arctic sea ice extent minimum:

Consistent with what might expect based on that paper, Lorenzo became a Category 5 hurricane tonight at 45W longitude. The NHC's update statement is below: 000 WTNT63 KNHC 290207 TCUAT3 Hurricane Lorenzo Tropical Cyclone Update NWS National Hurricane Center Miami FL AL132019 1010 PM AST Sat Sep 28 2019 ...LORENZO STRENGTHENS INTO A CATEGORY 5 HURRICANE... Recent satellite data indicate that Lorenzo has continued to rapidly strengthen to an extremely dangerous category 5 hurricane with maximum sustained winds near 160 mph (260 km/h). This increase in intensity will be reflected in the forecast issued at 11 pm AST (0300 UTC). SUMMARY OF 1010 PM AST...0210 UTC...INFORMATION ---------------------------------------------- LOCATION...24.1N 45.0W ABOUT 1410 MI...2270 KM SW OF THE AZORES MAXIMUM SUSTAINED WINDS...160 MPH...260 KM/H PRESENT MOVEMENT...N OR 360 DEGREES AT 10 MPH...17 KM/H MINIMUM CENTRAL PRESSURE...925 MB...27.31 INCHES $$ Forecaster Brown/Latto

Utqiagvik (formerly Barrow) remains solidly on course to experience its first September on record with a mean temperature of 40.0° or above. At present, a figure of 40.5° +/- 0.1° appears likely. Based on sensitivity analysis, there is an implied 97% probability of a 40.0° or above mean temperature. The current record is 37.7°, which was set in 1998. Overall, summer 2019 featured historic warmth in Alaska. Anchorage had its first 90° day. The meteorological summer mean temperature of 62.8° exceeded the mean figure for the hottest month on record prior to 2019 by 0.1°. In an opinion piece published in The New York Times three scientists, Vera Trainer, Rick Thoman, and Gay Sheffield, wrote about the impact climate change is having on Alaska and its environs. In part, they explained: Nome lies south of the Arctic Circle, on the edge of the Seward Peninsula along the northern Bering Sea. The peninsula is the closest point of the North American mainland to Russia. Months of darkness and daylight alternate there. And the effects of the warming climate are front and center. In June, people there told us, they watched a herd of musk ox retreat to small patches of snow that lingered in the hills as they panted through a three-day heat wave of temperatures at and above 80 degrees Fahrenheit. The normal daily maximum in June is 54.9 degrees. More ominous, the ocean is now free of ice most of the year; not that long ago, ice covered the sea near Nome generally from early November to late May. The ice is crucial to the sea life that is central to the people who live there... Over past centuries, the temperature gradient at the edge of the sea ice near Nome was a signal to marine animals that food was plentiful. Melting ice provides nutrients that fuel plankton blooms when sunlight is sufficient for photosynthesis. This ice melt during warmer, sunny days provides a banquet of plankton for small fish, shellfish and baleen whales. Those whales and other marine creatures typically followed the retreating ice, feasting as they hugged the Alaska coastline. Now whales often show up emaciated because the timing and extent of the ice melt has changed. The system is out of sync. The ice melt happens too early in the season, when shorter days and lack of sunlight are insufficient to nourish the algae blooms. What’s also troubling is the recent discovery of enormous cyst beds, the seedlike dormant resting stages of ocean algae, in ocean sediments in the Chukchi Sea, north of the Bering Strait. Unlike the nourishing blooms that bring life to the waters of Nome, these cysts can hatch into toxic algal blooms when the ocean warms. The toxins produced by these algae were recently detected at low levels in over a dozen species of marine mammals throughout Alaska, many of which are consumed by Native Alaskans. These algal toxins were also identified in dead sea birds — murres, fulmars and storm petrels — found during an unusual die-off in Alaska beginning in 2015. https://www.nytimes.com/2019/09/25/opinion/climate-change-ocean-Arctic.html

Tomorrow will complete a warmer than normal weekend in the region. Following a brief push of cooler air for Monday, there is potential for much above normal warmth to start October. The heat will likely peak on October 2 with readings in the middle and upper 80s into southern New England. Locations, including Washington, Baltimore, Philadelphia, Newark, and possibly even New York City could reach 90°. The PNA is forecast to plunge in coming days. Typically, a strongly negative PNA (-1.50 or below) during the October 1-3 period has translated into readings averaging 2°-4° above normal in the Middle Atlantic and southern New England regions. The warmth has been even more pronounced when the strongly negative PNA has coincided with a negative SOI. Afterward, a period of cooler than normal readings will move into the region during the latter part of the first week of October. This pattern could last 7-10 days. Events during September, including the SOI's falling to -35.30 on September 19 and the possible ongoing evolution toward a generally positive AO regime, favor a warmer than normal October based on past outcomes. However, recent guidance has increased uncertainty regarded to the AO's longer-term evolution. That situation bears watching, but the base case remains a warmer than normal October. Courtesy of low sea ice, there is a near 100% implied probability that Utqiagvik (formerly Barrow) will record its warmest September on record. It is very likely that Utqiagvik will register its first 40.0° mean temperature for September with an average temperature near 40.5°. A 40.5° mean temperature would rank 28th out of 99 years for the warmest August on record. The existing monthly record of 37.7° has stood since 1998. The ENSO Region 1+2 anomaly was -1.3°C and the Region 3.4 anomaly was -0.2°C for the week centered around September 18. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.77°C and the ENSO Region 3.4 anomaly has averaged -0.16°C. The recent strong cooling in Region 1+2 indicates that the prospects for a neutral-cool ENSO during the winter have continued to increase. Such a scenario is now more likely than not. Since 1991 when weekly ENSO region data was available, five years have seen September record 2 or more weeks with -1.0°C or cooler weekly anomalies in Region 1+2: 1996, 1999, 2007, 2010, and 2017. 4/5 (80%) of those cases went on to feature warm December-February temperature anomalies in the Middle Atlantic and southern New England regions. Those cases include La Niña winters. However, the larger pool of neutral-cool ENSO winters, many of which predate the weekly ENSO regional data, have often featured frequent Atlantic blocking. For now, there is a mixed winter signal. The SOI was -1.66 today. Today, the preliminary Arctic Oscillation (AO) figure was -0.291. 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. A warmer than normal September is now all but certain. A warmer than normal fall remains likely. The potential for autumn 2019 to rank among the 30 warmest cases on record has increased in recent weeks. For New York City, that would translate into a September-November mean temperature of at least 58.8°. On September 27, the MJO was in Phase 1 at an amplitude of 2.483 (RMM). The September 26-adjusted amplitude was 2.727. During the September 20-30 period, 2019 has seen five consecutive days where the MJO was in Phase 1 with an amplitude of 2.000 or above. Only 1977 (6 days) and 1999 (3 days) had three or more such days. The average temperature decline from the September 16-30 average in New York City was 8.8° (1977 had the largest at 9.4°). That would imply an October mean temperature near 60°, which reinforces the other data suggesting a warmer than normal October in the Middle Atlantic region. Based on sensitivity analysis applied to the latest guidance, the implied probability of New York City having a warmer than normal September is near 100% and the probability of a monthly mean temperature of 70.0° or above is 63%. Should September 2019 have a mean temperature of 70.0° or above, 2019 would be the 5th consecutive year with such September warmth. Prior to the current stretch, the record was 2 consecutive years (1930 and 1931; 1970 and 1971; 1979 and 1980; and, 2010 and 2011).

Under bright sunshine and temperatures in the lower 80s, the Monarch migration was well underway. Some photos from the New York Botanical Garden:

At the time Syria's civil war erupted, there had been a severe and ongoing drought. It's plausible that the drought was one variable that contributed to that outcome.