donsutherland1

From the NHC's 11:00 AST discussion: The risk of other direct impacts associated with Florence along the U.S. East Coast next week has increased. However, there is still very large uncertainty in model forecasts of Florence's track beyond day 5, making it too soon to determine the exact location, magnitude, and timing of these impacts. Interests near and along the U.S. East Coast should monitor the progress of Florence through the weekend and ensure they have their hurricane plans in place.

Such a track is well within the realm of possibility. The threat to the East Coast has increased in recent days. By early next week, the details will start to come into focus.

Through September 6, New York City (Central Park) has had a mean monthly temperature of 80.2°. Only 1898 (84.2°), 1953 (83.1°), 1973 (82.6°), and 1961 (82.3°) had a warmer start to the month. Further, since 1869, only 7 prior years saw September 1-6 have a mean temperature of 80.0° or above. In 4/7 (57%) of those prior cases, September wound up having a mean temperature of 70.0° or above. The average figure for those cases was 70.5° and the median figure was 70.3°. If 2018 has a mean September temperature of 70.0° or above, the record streak of consecutive years with such September warmth would be extended to 4. The evolving climate has increased the probability of such warmth in September. Since 1869, there have been 34 cases during which September had a mean temperature of 70.0° or above. 19 (56%) of those cases occurred 1950 and afterward; 12 (35%) of those cases occurred 1980 and afterward. The return time of such September warmth has been decreasing: Historic (1869-2017): 4.4 years Prior to 1950: 5.4 years 1950-2017: 3.6 years 1980-2017: 3.2 years 1990-2017: 3.1 years 2000-2017: 2.3 years 2010-2017: 1.6 years Overall, the September mean temperature has also been increasing: Historic (1869-2017): 67.9° 1961-1990: 68.1° 1971-2000: 68.1° 1981-2010: 68.4° 1988-2017 (latest 30-year period): 68.9° 2000-2017: 69.5° 2010-2017: 70.5° Warmest 30-Year Period on record: 1988-2017: 68.9° Warmest 10-Year Period on record: 2008-2017: 69.9° Based on sensitivity analysis, sing a combination of the actual temperatures through 9/6, the MEX MOS for the next 10 days, and the EPS for the 5 days, and then seasonal readings for the remainder of the month, there is an implied 57% (+/- 5%) probability that September 2018 will have a mean temperature of 70.0° or above. That is almost an identical probability to the historic figure for cases where 9/1-6 had a mean temperature of 80.0° or above. Finally, there is an implied one-in-three chance that September 2018 could go on to have a mean temperature that tops the 74.5° record that was set in 2015.

2015-16 had the strongest El Niño on record. 2016-17 was a la niña winter. Also, on a separate note, the 6z GFS seems to have come more in line with the EPS (northern cluster of solutions) in taking Florence up the Chesapeake Bay. The ECMWF was in the southern cluster.

Providence has had 21 90° days (same as 1941 and 1980). Only 1983 (30), 1944 (29), and 2002 (26) had more. Providence has also seen the average number of such days per year increase. 1951-80: 7.9; 1989-2018: 11.2; 2010-18: 13.1; Historic 1905-2018 Period: 9.6 The evolving El Niño probably makes 2002 a better match than 1983 (1982-83 had a much stronger and basinwide El Niño event).

Some of the hits on the 18z GEFS included: NC, the NC-VA border, central-southern NJ, and eastern Long Island.

Today was Boston’s 23rd day on which the temperature reached 90° or higher. Only 6 years have had more such days: 1983: 30 1955: 28 1991 and 2002: 27 1988 and 2010: 25 The return time for years with 20 or more such days has been falling. Historic (1872-2018): 9.2 years Prior to 1950: 19.8 years 1950-2018: 5.8 years 1980-2018: 3.9 years 2010-2018: 3.0 years The average number of 90° days per year has also been increasing. Historic (1872-2018): 11.7 per year 1921-50: 11.9 per year 1951-80: 12.6 per year 1989-2018: 13.7 per year 2010-2018: 16.2 In addition, 3 of Boston’s 10 days with minimum temperatures of 80° or above have occurred in the 2010-2018 period. The August 29, 2018 minimum temperature of 81° was, by far, Boston’s latest such minimum temperature on record. The previous latest 80° minimum temperature was set on August 2, 1975.

The “new info” was probably the GFS. No other model was running at that time. It’s too soon to reach firm conclusions, but Florence should be watched. A threat still exists. The EPS shows it.

JFK was 89 and NYC was 93. It’s been drier up in New England and I am sure that contributed.

Record High Temperatures for 9/6 (through 5:00 PM) Albany: 91° (tied record set in 1983) Boston: 97° (old record: 94°, 1983) Bridgeport: 92° (tied record set in 1983) Concord: 92° (old record: 91°, 1998) Hartford: 96° (tied record set in 1983) Georgetown: 93° (tied record set in 2014) Manchester: 93° (old record: 92°, 1971) New Haven: 91° (old record: 87°, 2014) New York City-LGA: 96° (old record: 94°, 1983) Newark: 98° (tied record set in 1983) Portland: 92° (old record: 88°, 1880, 1884, and 1983) Providence: 95° (tied record set in 1983) Teterboro: 95° (tied record set in 2014) Trenton: 95° (tied record set in 1910) Westhampton: 85° (tied record set in 2015) The following locations have had high temperatures of 95° or above: Boston: 97° Hartford: 96° New York City-LGA: 96° Newark: 98° Providence: 95° Teterboro: 95° Trenton: 95°

Record High Temperatures for 9/6 (through 4:00 PM) Albany: 91° (tied record set in 1983) Boston: 97° (old record: 94°, 1983) Bridgeport: 92° (tied record set in 1983) Concord: 92° (old record: 91°, 1998) Georgetown: 93° (tied record set in 2014) Manchester: 93° (old record: 92°, 1971) New Haven: 91° (old record: 87°, 2014) New York City-LGA: 96° (old record: 94°, 1983) Newark: 98° (tied record set in 1983) Portland: 92° (old record: 88°, 1880, 1884, and 1983) Teterboro: 95° (tied record set in 2014) Trenton: 95° (tied record set in 1910) Westhampton: 85° (tied record set in 2015) The following locations have had high temperatures of 95° or above: Boston: 97° Hartford: 95° New York City-LGA: 96° Newark: 98° Teterboro: 95° Trenton: 95°

Record High Temperatures for 9/6 (through 3:00 PM) Albany: 91° (tied record set in 1983) Boston: 96° (old record: 94°, 1983) Bridgeport: 92° (tied record set in 1983) Concord: 92° (old record: 91°, 1998) Georgetown: 93° (tied record set in 2014) Manchester: 93° (old record: 92°, 1971) New Haven: 91° (old record: 87°, 2014) New York City-LGA: 96° (old record: 94°, 1983) Newark: 97° (tied record set in 1983) Portland: 92° (old record: 88°, 1880, 1884, and 1983) Teterboro: 95° (tied record set in 2014) Westhampton: 85° (tied record set in 2015) The following locations have had high temperatures of 95° or above: Boston: 96° Hartford: 95° New York City-LGA: 96° Newark: 97° Teterboro: 95°

Record High Temperatures for 9/6 (through 2:00 PM) Albany: 91° (tied record set in 1983) Boston: 95° (old record: 94°, 1983) Concord: 92° (old record: 91°, 1998) New Haven: 89° (old record: 87°, 2014) New York City-LGA: 96° (old record: 94°, 1983) Portland: 92° (old record: 88°, 1880, 1884, and 1983) Westhampton: 85° (tied record set in 2015) The following locations have had high temperatures of 95° or above: Boston: 95° Hartford: 95° New York City-LGA: 96° Newark: 96°

The 9/3/2018 minimum temperature of 76° at New Haven set a new September record. The previous warmest minimum temperature on record in New Haven was 75°, which was set in 1977 and tied in 2014 and 2015. So far, today's minimum temperature there is 77°, however possible thunderstorms could result in a lower figure by day's end.

Record High Temperatures for 9/6 (through 1:00 PM) New Haven: 87° (tied record set in 2014) Portland: 91° (old record: 88°, 1880, 1884, and 1983) **1 pm: 73° TSRA+** Westhampton: 85° (tied record set in 2015)

No. Today is the 9th day. The record is 16, which was set in 1955.

I agree. Also, LGA’s 80 degree minimum temperature on 9/4 was the latest on record.

Record High Temperatures for 9/6 (through 12:00 PM) Portland: 91° (old record: 88°, 1880, 1884, and 1983) Westhampton: 85° (tied record set in 2015)

Record High Minimum Temperatures for 9/6 (Preliminary) Atlantic City: 78° (old record: 74°, 1953, 1985, and 1999) Bridgeport: 78° (old record: 75°, 1985) Harrisburg: 75° (old record: 74°, 1898 and 1985) Hartford: 73° (old record: 72°, 1983) Islip: 76° (old record: 75°, 1985) New Haven: 77° (old record: 72°, 1953 and 1985) New York City-LGA: 79° (tied record set in 1985) New York City-NYC: 78° (tied record set in 1985) Newark: 77° (tied record set in 1985) Philadelphia: 78° (old record: 76°, 1898) Poughkeepsie: 71° (tied record set in 1985) Sterling: 72° (tied record set in 1996) Washington, DC: 78° (old record: 77°, 1983) Westhampton: 75° (old record: 72°, 1953 and 1999)

Record High Temperatures for 9/5 (through 5:00 PM): Albany: 92° (old record: 91°, 1973) Binghamton: 87° (tied record set in 1983) Burlington: 93° (old record: 90°, 1973) Concord: 91° (tied record set in 1953 and tied in 1961) Erie: 93° (old record: 92°, 1881) Georgetown: 93° (tied record set in 1961) Harrisburg: 94° (old record: 93°, 1954) Philadelphia: 95° (old record: 92°, 1961, 1973 and 1985) Scranton: 91° (old record: 90°, 1983) Trenton: 93° (tied record set in 1910) Wilmington, DE: 93° (tied record set in 1961 and tied in 1983)

Record High Temperatures for 9/5 (through 3:00 PM): Albany: 91° (tied record set in 1973) Burlington: 92° (old record: 90°, 1973) Erie: 92° (tied record set in 1881) Georgetown: 93° (tied record set in 1961) Harrisburg: 93° (tied record set in 1954) Philadelphia: 95° (old record: 92°, 1961, 1973 and 1985) Scranton: 90° (tied record set in 1983)

The UKMET is a southern outlier right now, but the pattern continues to strongly argue for East Coast interests to watch Florence. The 0z EPS vividly illustrated the risk.

Record High Temperatures for 9/5 (through 2:00 PM): Burlington: 90° (tied record set in 1973) Erie: 92° (tied record set in 1881) Georgetown: 93° (tied record set in 1961) Harrisburg: 93° (tied record set in 1954) Philadelphia: 94° (old record: 92°, 1961, 1973 and 1985) Scranton: 90° (tied record set in 1983)

Record High Temperatures for 9/5 (through 1:00 PM): Erie: 92° (tied record set in 1881) Philadelphia: 92° (tied record set in 1961 and tied in 1973 and 1985) Additional locations with temperatures of 92°: Baltimore and Rochester. Also, LGA has reached 90°.

Select Record-High Minimum Temperatures for 9/5 (preliminary): Atlantic City: 74° (tied record set in 1953) Harrisburg: 74° (old record: 73°, 1961, 1985,and 1999) New York City-LGA: 79° (tied record set in 1985) New York City-NYC: 77° (tied record set in 1898 and tied in 1907 and 1985) Newark: 78° (tied record set in 1961) Teterboro: 76° (old record: 72°, 1999) Washington, DC: 78° (tied record set in 2012) Yesterday was LGA’s 84th minimum temperature of 80° or above on record. 45 (54%) have occurred in the period beginning in 2000, including 24 (29%) during the period beginning in 2010. Under LGA’s historic climatology, such readings occurred 1.1 times per year, on average. Since 2000, they have occurred an average of 2.4 days per year and since 2010, they have occurred an average of 2.7 times per year.