Friday, June 25, 2010

First 2010 Atlantic Basin Tropical Depression Forms
Possible Threat to Gulf of Mexico

The tropical wave which has been moving westward across the Caribbean has been declared a tropical depression by the National Hurricane Center as of 6 pm EDT. If it develops further, it will become Tropical Storm Alex. This could happen as early as tonight or Saturday.

The forecast track brings the storm across the Yucatan Peninsula and then into the southern Gulf of Mexico by late this weekend. Based on the expected track, there is at least a 5% chance of tropical storm force winds nearly anywhere in the western half of the Gulf in the next 5 days.

Summary information at 6 pm:
LOCATION...16.5N 83.5W

Image (click to enlarge): Probability of tropical storm winds for the 5 days beginning 2 pm EDT, June 25, 2010, from National Hurricane Center

Earlier this afternoon, CNBC reviewed the possible impacts of a tropical storm on the BP oil gusher cleanup and oil markets. "The timing couldn't be worse."

Thursday, June 24, 2010

Triple-Digit Heat Smashes Washington DC, Mid Atlantic Temperature Records

See here for more Washington DC weather records.

See here for June 27 update.

June 24 Update: Here are the preliminary temperature record counts for the entire U.S. on June 24:
Warmest max temperature 36
Coldest min temperature 1
1 AM Update: It's not official, but the new record high minimum temperature of 78° appears to have held.

Evening Update: More record reports from major reporting locations (previous records in parentheses):
Richmond            102 (100, 1948)
Wallops Island VA 99 (92, 2002/1997)
New Bern NC 97 (96, 1960)
Atlantic City 99 (96, 1966)
Georgetown DE 97 (96, 1988)
Note that the Atlantic City record was broken by 3° in an observation history which extends back to 1874.

It's still 90° in Washington at 7 pm.

Late PM Update: The preliminary highs reported by the National Weather Service:
Washington National 100 @ 2:32 PM
Washington Dulles 97 @ 1:48 PM
Baltimore BWI 100 @ 1:54 PM
All of them are new records by 2° each. The previous Baltimore record had occurred 3 times in the past: 1966, 1908, 1894.

The Washington morning low of 78°, if it holds through midnight (1 am EDT), would also be a new record high minimum, beating the old record of 77° which has stood since 1874. Given the lack of rainfall so far, that seems like a distinct possibility. The 1874 record is the oldest of only 3 remaining 19th century daily high minimum records for June. A daily high minimum record (76°) has already been set this month on the 21st.

Here are some other high temperature records reported by the National Weather Service so far today (previous records in parentheses):
Raleigh            99 (tie, 1996)
Elizabeth City NC 99 (97, 1981)
Wilmington NC 98 (97, 1950)
Islip NY 93 (91, 2003)
Kennedy Airport NY 97 (95, 1966)
LaGuardia Airpt NY 95 (93, 2003)
PM Update: 3 pm temperatures:
Washington National  98
Washington Dulles 95
Baltimore BWI 100
Original post:
The official Washington DC temperature of 99° at 2 pm today has already broken the heat record for June 24 set in 1894 as readings continue to climb. That record was one of only 3 remaining June high temperature records from the 19th century, including the all-time June daily high of 102° on June 9, 1874. (By contrast, 5 daily low temperature records remain from the 19th century. Only one June daily low temperature record has been set since 1979, and that was 18 years ago, on June 22, 1992.)

Other temperatures around the region include:
Baltimore (BWI)   100 (old record 98, 1966)
Richmond 101 (old record 100, 1948)
Petersburg VA 100
Williamsburg VA 102
Patuxent River MD 100
Fredericksburg VA 99
Frederick MD 99
Leesburg VA 99
Ocean City MD 98

Wednesday, June 23, 2010

Washington Approaches Ties Exceeds All-Time June Temperature Record

June 25 Update: Yesterday's record high of 100° and record high minimum of 78° bring the month-to-date average up to 79.9°, 6.1° above average and half a degree above the old June record.

June 23 Evening Update: Today's preliminary high temperature was 97°, giving a departure from average of +10°.

June 23 Late PM Update: The 5 pm temperature of 96° has pushed the daily average to at least 85° and the month-to-date to 79.5°, assuming the morning low holds through midnight. This exceeds by 0.1° the average for the record hottest June in 1994. It also exceeds the average July temperature of 79.2°. (Chart updated with current data.)

The record warm June temperatures extend at least as far south as Richmond, where the monthly average to date of 80° exceeds the record of 79.2° in 1943.

June 23 PM Update: With a 1 pm temperature reaching 94° following a morning low of 74°, the daily average so far today of 84° pushes the June mean to at least 79.4°, tying the June record in 1994.

This is now the 5th consecutive 90°+ day and the 12th so far this month.

Original post:
Washington's high temperature of 96° on Tuesday was well short of the record for June 22 of 101° in 1988, but the day's average of 85° was 9° above the normal for the date. This raised the monthly average so far by 0.3° to 79.3°, just 0.1° below the all-time June record set in 1994 and 0.5° above the second-warmest June in 1943. The long-term average temperature for June is 74.5°.

There have now been 11 days in June with high temperatures of 90° or above, including the last 4 consecutive days. Since the average number for the entire month of June is 7.4, this is a little more than double the normal ratio of 90°+ days.

Tuesday, June 22, 2010

Dozens Dead, Hundreds Missing in Brazil Floods

June 22 Update: The New Zealand Met Service blog reports phenomenal rains in the early part of June (tip of the wind vane to Hot Topic).

Original post:
The Northern Hemisphere is not unique in experiencing recent heavy flooding. Dozens are known dead, hundreds are missing, and perhaps as many as 100,000 are homeless following several days of torrential rainfall, as much as 14", in northeastern Brazil. Flooding is reported to have destroyed entire villages in the states of Alagoas and Pernambuco.
Video from Associated Press:

First Hurricane of 2010 Reaches Category 2 Strength
Tropical Wave Has 50% Potential For Development

June 22 Update: The Caribbean tropical wave has not become better organized today, so the chances of development in the next 48 hours have been reduced to 20%. However, environmental conditions are likely to become more favorable for slow development as it continues to move westward.

Original post:
Celia, which became the first hurricane of the 2010 Eastern Pacific season early Sunday afternoon, has reached Category 2 strength as of 8 pm EDT today. The storm is centered a little over 500 miles south of Manzanillo, Mexico. It is moving west at about 8 mph. Although a more northerly track is expected later in the week, Celia is likely to remain well offshore.

Meanwhile, in the Atlantic Basin, a strong tropical wave in the central Caribbean is now given a 50% chance of developing into a depression in the next 48 hours. If a storm does develop, it has the potential of eventually moving northward into the Gulf of Mexico.

Image (click to enlarge): Atlantic Tropical Weather Outlook as of 8:15 pm EDT, June 21, from National Hurricane Center

Monday, June 21, 2010

Global Temperature Trifecta: Warmest May, Warmest Spring/Fall, Warmest Year-to-Date
Record Low N. Hemisphere Snow Cover

NOAA's National Climatic Data Center (NCDC) has announced that global average temperatures were the warmest on record for:
  • Month of May 2010 (0.69°C/1.24°F above the 20th century average of 14.8°C/58.6°F)
  • Meteorological Spring (Northern Hemisphere)/Autumn (Southern Hemisphere) (0.73°C/1.31°F above the 20th century average)
  • 2010 Year-to-Date (0.68°C/1.22°F warmer than the 20th century average)
Global temperature records extend back 130 years to 1880.

For the month of May, most of the world's land areas were warmer than average, especially eastern North America, eastern Brazil, Scandinavia, eastern Europe, equatorial and southern Africa, eastern Russia, and southern Asia. Temperatures in eastern North America, for example, were 2°C (3.6°F) to 4°C (7.2°F) above normal. On the other hand, temperatures were below average in western North America, northern Argentina, western Europe, and interior Asia.

Ocean temperatures for May were also considerably above average by 0.55°C (0.99°F). This was the second warmest May for sea surface temperatures behind 1998. These warm averages occurred despite the cooling of equatorial Pacific temperatures, signaling the end of El Niño conditions.

In the Northern Hemisphere, rapid spring melting resulted in the lowest snow cover extent since satellite observations began in 1967. Average snow cover for the month was 4.3 million square kilometers (1.7 million square miles) below the long-term average.

Images (click to enlarge): Global temperature departures from average for May 2010, March-May 2010, and January-May 2010; historical Northern Hemisphere May snow cover departures from average, all from NCDC

Seasonal Outlook

Latest seasonal forecast: Click here.

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