Wednesday, September 8, 2010

Endless Summer IV: DC's 62nd Day of 90°+ Temperatures

8 PM Update: And 96° it is, at 3:46 PM EDT. Temperatures were 90° or above for 8 consecutive hours beginning at noon. The low of 74° is no slouch either, just 2° below the record highest minimum for the date, if it holds through midnight. That certainly looks feasible, although temperatures will be dropping quickly. Overall, at this rate, the day is adding 12° of surplus over the long term average.

5 PM Update: The temperature was 95° for 3 consecutive hours; that's probably good enough for a high of 96°.

2 PM Update: Preliminary high: 95°. (WaPo's non-carbonated edition forecast: "Upper 80s to near 90". Yeah, that's pretty near. NOT.)

Original post:
That crashing noise around noon today in the Washington metro area was the sound of temperature forecasts busting as the mercury once again reached 90°. It rose 3 more degrees in the following hour to 93°. This is now the 62nd day of 90°+ temperatures in 2010. Although that is still 5 days ahead of the torrid pace toward 67 days in the record-setting year of 1980, temperatures will drop to more seasonable levels for at least the rest of the week, and 2010 may, for the first time all year, drop behind the record pace.

Images (click to enlarge): Washington/Baltimore regional temperatures shortly after 1 pm EDT, Sept. 8, 2010, from Intellicast; Cumulative annual number of days 90° or higher in Washington, CapitalClimate chart from National Weather Service data

Tuesday, September 7, 2010

Endless Summer III: 'Nother Ninety Notched
61st Day of 90°+ Temperatures

5:30 PM Update: The preliminary high/low temperatures for Sept. 7 are 94/69. If the low holds through midnight, the first week of September will average nearly 6° above the long-term mean.

Original post:
At 3 pm today, the temperature at Washington National jumped 4° in an hour, reaching 93°. Following a record hot spring and summer, this is the 61st day of 90°+ temperatures at Washington in 2010. The record for one year is 67 in 1980. The total didn't reach 61 in 1980 until 5 days later, however.

Temperatures at other major regional reporting locations were also 90° or above; 91° at Washington Dulles and 90° at Baltimore/BWI.

Monday, September 6, 2010

Record Hot Spring-Summer in Northeast, Mid Atlantic

Images (click to enlarge): U.S. Northeast and Mid Atlantic temperature departures from average for spring (March-May) and summer 2010 (June-August) from NOAA Applied Climate Information System (ACIS)

Not only have a number of summer temperature records been set this year, but a majority of major climate reporting stations in the Northeast and Mid Atlantic (26 locations) have set or tied records for the hottest spring-summer (March-August). Here is the NOAA summary of 2010 temperatures vs. the previous records:
                                2010    Previous
Average Year Average Difference
Atlantic City NJ 66.8 1991 64.5 2.3
Washington/Dulles VA 68.2 1991 66.4 1.8
New York/JFK NY 66.3 1991 64.6 1.7
Newark NJ 68.1 1993 66.5 1.6
Worcester MA 60.7 1949 59.2 1.5
Providence RI 63.9 1945 62.5 1.4
New York/LaGuardia NY 68.3 1991 66.9 1.4
Hartford/Bradley CT 64.0 1991 62.8 1.2
Washington National DC 70.9 1991 69.7 1.2
Caribou ME 54.7 1979 53.5 1.2
Central Park NY 67.5 1991 66.3 1.2
Philadelphia PA 68.9 1991 67.7 1.2
Islip NY 64.2 1991 63.1 1.1
Bridgeport CT 64.3 1991 63.2 1.1
Wilmington DE 67.2 1973 66.2 1.0
Boston MA 63.4 1991 62.4 1.0
Binghamton NY 59.7 1991 58.8 0.9
Baltimore/BWI MD 68.4 1921 67.6 0.8
Concord NH 59.5 1921 58.7 0.8
Burlington VT 59.4 1894 58.6 0.8
Middletown/Harrisburg PA 66.5 1991 65.9 0.6
Williamsport PA 64.4 1921 64.0 0.4
Portland ME 58.8 1878 58.4 0.4
Allentown PA 64.1 1991 63.7 0.4
Syracuse NY 61.1 1921 60.9 0.2
Scranton PA 62.4 1921 62.4 0.0
Five more stations had their second hottest spring-summer:
                               2010     Previous
Average Year Average Difference
Albany NY 61.6 1921 61.8 (0.2)
Elkins WV 61.5 1921 61.7 (0.2)
Beckley WV 62.9 1991 63.2 (0.3)
Buffalo NY 60.3 1991 60.7 (0.4)
Rochester NY 60.7 1921 61.6 (0.9)
Two other stations (Charleston WV and Erie PA) had their 3rd hottest spring-summer, Pittsburgh PA had its 6th hottest, and Huntington WV had its 7th hottest.

Sunday, September 5, 2010

Summer of Simmer Summary: More Heat Records Broken

As previously reported, it was the hottest summer on record by a wide margin in Washington. Record-breaking heat also extended from the Mid Atlantic area into the Southeast. Here are some other summer 2010 heat records (more records to be added as available):

Central Park NY: Hottest summer, average 77.8° vs. 77.3° in 1966. [Records began 1869]

Baltimore MD: Hottest summer, average 79.3° vs. 79.1° in 1943.

Roanoke VA: Hottest summer, average 78.2° vs. 77.4° in 1987.

Danville VA: Hottest summer, average 80.0° vs. 78.7° in 1952.

Blacksburg VA: Hottest summer, average 72.9° vs. 72.3° in 1987.

Bluefield WV: Hottest summer, average 74.5° vs. 74.2° in 2007.

Raleigh NC: Hottest summer, average 81.7° vs. 79.8° in 2007. Most June-August 90°+ days, 67 vs. 58 in 2007 and 1992.

Greensboro NC: Hottest summer, average 80.1° vs. 78.5° in 2007 and 1993. Most June-August 90°+ days, 52 vs. 50 in 1993.

Asheville NC: Hottest summer, average 75.4° vs. 75.1° in 1952.

Charlotte NC: Second hottest summer, average 81.1° vs. 81.5° in 1993.

Greenville-Spartanburg SC: Hottest summer, average 81.0° vs. 80.2° in 1952.

Savannah GA: Second longest string of 90°+ temperatures, 40 ending Aug. 14, vs. 44 ending Aug. 8, 1993.

Chattanooga TN: Second hottest summer, average 84.0° vs. 85.7° in 2007.

Image (click to enlarge): U.S. surface temperature departure from average (°C), June 1 to August 31, 2010, from NOAA/ESRL Physical Sciences Division, Boulder Colorado

Seasonal Outlook

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Latest 3-month temperature outlook from Climate Prediction Center/NWS/NOAA.