July 22, 2011: A day of records

The crest of the extreme heat wave of July 2011 has passed, although temperatures are still going to be dangerously hot in the Mid-Atlantic and Northeast today. New York City (Central Park) will reach 100° again, as well as Philadelphia and possibly Washington Dulles. Heat index values could surpass the 110° mark today, and excessive heat warnings are in effect from New York City to South Carolina, as well as a large portion of the Central United States. Yesterday, the heat index soared past 120° in Wilmington, DE (124), Easton, MD (125), Annapolis, MD (120) and Atlantic City, NJ (122), among others. A more complete list of Friday's heat index extremes can be found here.

Numerous records fell yesterday as far north as Maine. There were plenty of daily records to talk about, but here are some of the noteworthy all-time record high temperatures:

• Newark, NJ: 108° (old record was 105° set in 2001)
• Washington Dulles, DC: 105° (old record was 104° on multiple dates)
• Bridgeport, CT: 103° (ties the old record set in 1957)
• Hartford, CT: 103° (old record was 102° set on multiple dates)
• New Haven, CT: 102° (old record was 101° set in 1926)

Baltimore hit 106°, one degree shy of their all-time high record which was set in 1936. New York City (Central Park) set a daily record of 104°, which was 2 degrees shy of their 106° all-time high record, which was also set in 1936. More on the record-setting year of 1936 in yesterday's blog from Jeff. Two notable all-time record high minimums were also set yesterday: 84° in New York (Central Park) and 86° in Newark, NJ.

Our weather historian, Christopher C. Burt, keeps track of 303 select stations in the U.S. with long standing record histories. So far this summer, seven of these have broken or tied their all-time maximum temperature records. Some of these were long-standing:

• Amarillo, TX 111° (1892)
• Dodge City, KS 110° (1874 tied)
• Newark, NJ 108° (1893)
• D.C. Dulles 105° (1962)
• Tallahassee, Fl 105° (1883)
• Hartford, CT 103° (1885)
• New Haven, CT 102° (1780)

The last summer to have more all-time high records than this year was 2002, which set 9. Christopher C. Burt estimates that yesterday probably rates in the top five hottest days on record for the mid-Atlantic states (Washington D.C. to Boston).

Invest 90L


Satellite imagery of NHC Invest 90L this morning.

Invest 90L is looking ragged on satellite as it makes its way across the Caribbean islands. While this wave looked ripe for eventual development earlier this week, it has really taken a turn for the worse as it moved across the Main Development Region of the North Atlantic. Today, low level circulation is could favorably be described as less than moderate, and almost nonexistent at higher levels. Today, not one of the global models I've looked at (ECMWF, NOGAPS, CMC, UKMET, or GFS) develop 90L, but they are coming into better agreement that the wave's track will be across the Caribbean islands and into the Gulf of Mexico, rather than up the east coast of Florida. This could be one of the reasons the models are not suggesting development—too much land interaction, not enough time over open warm waters. However, its hard to say that this wave will not show some signs of improvement when it reaches the Gulf. Water will be toasty, moisture will be relatively high, and wind shear will remain incredibly low. Today the National Hurricane Center is giving this wave a 20% chance of development over the next 48 hours. My forecast has been the same for the past two days, right around 20% chance of development over the lifetime of the wave.

Thanks to our weather historian Christopher C. Burt for some useful information on heat waves and yesterday's records. I'll have another blog on Monday.

Angela