Tropical Update: Bill is Born Advisories for Ana

Satellite imagery indicates that the Tropical Depression formerly known as Three has become better organized and is now Tropical Storm Bill with maximum winds of 40 mph. Bill is in the deep tropics, further south than Ana, and is well within the easterly trade winds. It's moving steadily a little south of due west around 16 mph, and a gradual turn to the west-northwest is expected. Bill has a large circulation and has favorable conditions for development, including light wind shear and warm water temperatures. It is expected to become a hurricane within 4 days.

Meanwhile, little sister Ana still has maximum winds of 40 mph as it continues moving westward at 17 mph. The Netherlands Antilles government has issued a tropical storm watch for St. Maarten, Saba, and St. Eustatius.

Images (click to enlarge): Tropical Storms Bill and Ana forecast tracks from National Hurricane Center

Tropical Season Heats Up: Ana Arrives Brother Bill Behind?

After being given up for dead, the remnants of Tropical Depression 2 organized enough this morning to become Tropical Storm Ana, the first of the 2009 Atlantic season. Meanwhile, a larger tropical wave to the southeast of Ana has become Tropical Depression 3; it is likely to develop into Tropical Storm Bill in the next day or so.

At 11 am AST/EDT, Ana's maximum winds were 40 mph, and some slow strengthening is predicted. Movement is toward the west at 16 mph, with a gradual turn to the west-northwest expected. This track could bring the storm near the Leeward Islands by Monday. Ana is a small storm, and it is moving through a hostile environment of westerly wind shear and dry air, but the forecast track takes it over increasingly warm water. Most of the intensity models indicate that it could develop into a hurricane. Given the conflicting influences, however, the intensity forecast is more uncertain than usual; the official forecast keeps it lower than the models, at tropical storm strength.

Tropical Depression 3 formed late this morning in the eastern Atlantic. Maximum winds are 35 mph and movement is westward at 17 mph from a position about 740 miles west-southwest of the Cape Verde Islands. The intensity forecast calls for the depression to become a tropical storm in the next 12 hours and a hurricane within 3 to 4 days. All of the intensity models are predicting hurricane strength, with one of them forecasting a major hurricane. If it develops as expected, the storm will be named Bill.

Images (click to enlarge): Tropical Storm Ana and Tropical Depression 3 forecast tracks from National Hurricane Center

NOAA Reports 5th Warmest July on Record Globally Ocean Temperature Warmest on Record

NOAA's National Climatic Data Center (NCDC) late Thursday released its preliminary analysis of July 2009 global temperatures. It found that the global average land and ocean surface temperature was the 5th warmest on record, 0.57°C (1.03°F) above the 20th century average of 15.8°C (60.4°F). The ocean surface temperature broke the 1998 record to become the warmest for the month of July at 0.59°C (1.06°F) above the 20th century average of 16.4°C (61.5°F). The departure from the long-term average was equal to June's record amount. Other highlights from the NCDC report:

• July 2009 was the 33rd consecutive July with an average global land and ocean surface temperature above the 20th century average. The last July with global temperatures below the 20th century average occurred in 1976.
  
• The global land surface temperature for July 2009 was 0.51°C (0.92°F) above the 20th century average of 14.3°C (57.8°F), and tied with 2003 as the ninth-warmest July on record.
  
• For the year to date, the global combined land and ocean surface temperature of 14.3°C (57.9°F) tied with 2004 for the sixth-warmest January-through-July period on record.

Tropical Depression 2 Fades Away Prospects for Next System Look Stronger

August 15 Update: TD 2 has revived and become Tropical Storm Ana.

Original post:
Unlike the little engine that could, Tropical Depression 2 was the heat engine that couldn't. The system, small in size to begin with, struggled against increasingly dry surrounding air and unfavorable wind shear until it faded away to a remnant low pressure area with maximum winds of 30 mph this afternoon. The last official advisory was issued by the National Hurricane Center at 5 pm today.

The next system, a tropical wave about 250 miles south of the Cape Verde Islands, is becoming better organized, and it's being given a high chance (greater than 50%) of becoming a tropical cyclone in the next couple of days.

Image (click to enlarge): Atlantic tropical cyclone activity map from National Hurricane Center

Texas Heat Records Continue Falling

For previous record temperature posts, see:
Record Heat
Record Cold

The persistent heat of Summer 2009 continues to break records in Texas, especially in the southern part of the state. For Corpus Christi and Victoria, the National Weather Service reports:

MUCH ABOVE NORMAL TEMPERATURES HAVE CONTINUED ACROSS SOUTH TEXAS   
FOR THE MONTH OF AUGUST AFTER RECORD HEAT WAS OBSERVED FOR THE   
MONTHS OF JUNE AND JULY. THE CURRENT HEAT WAVE IS BYPASSING RECORDS   
FOR THE SUMMER PERIOD SET IN 1953 AND 1998 FOR BOTH CORPUS CHRISTI  
AND VICTORIA.   
  
RECORDS ARE ALSO BEING SET FOR LONGEVITY FOR ABOVE NORMAL MAXIMUM   
TEMPERATURES. CORPUS CHRISTI HAS SEEN HIGH TEMPERATURES ABOVE 95  
DEGREES FOR 36 STRAIGHT DAYS AND COUNTING AS OF AUGUST 12TH. THIS  
BREAKS THE MARK OF 26 DAYS SET IN SEPTEMBER OF 2005. FOR THE   
VICTORIA AREA...THE STREAK OF 36 DAYS ABOVE 96 DEGREES SURPASSES  
HEAT WAVES THAT OCCURRED IN THE EARLY 1900S (1911, 1912, 1917).      
IF IT WERE NOT FOR ONE MINOR COOL DOWN ON JULY 7TH...THE STREAKS   
FOR BOTH CORPUS CHRISTI AND VICTORIA WOULD BE ABOVE 50 DAYS.  
  
EXCEPTIONAL DROUGHT CONTINUES FOR SOUTH TEXAS WITH YEARLY RAINFALL   
DEFICITS AT 13.59 INCHES FOR CORPUS CHRISTI...AND 16.72 INCHES AT   
VICTORIA AS OF AUGUST 11TH. THE CURRENT DROUGHT IS ON PAR WITH THE   
DROUGHT THAT OCCURRED IN 1917 ACROSS SOUTH TEXAS.  

CLIMATE RANKINGS THROUGH AUGUST 11TH 2009 FOR THE CORPUS CHRISTI AND   
VICTORIA AREAS.  
  
CORPUS CHRISTI (PERIOD OF RECORD 1887-2009)...  
  
HIGHEST JUNE MONTHLY MEAN OF 'DAILY AVERAGE TEMPERATURE' DEGREES F   
  
RANK    VALUE   ENDING DATE  
  1      85.8    1998, 1953  
  3      85.0    2009  
  
HIGHEST JULY MONTHLY MEAN OF 'DAILY AVERAGE TEMPERATURE' DEGREES F   
  
RANK    VALUE   ENDING DATE  
  1      87.9    2009  
  2      87.1    1953  
  3      86.6    1998  
  
HIGHEST MEAN OF 'DAILY AVERAGE TEMPERATURE' FROM JUNE 1-AUGUST 11  
  
RANK    VALUE   ENDING DATE  
  1      86.7    2009  
  2      86.6    1953  
  3      86.2    1998  
  
YEARLY TOTAL NUMBER OF DAYS WITH MAXIMUM TEMPERATURE ABOVE 95   
DEGREES F  
  
RANK    VALUE   ENDING DATE  
  1      64      2009 (AS OF AUGUST 12)   
  2      62      1953  
  3      56      2005  
  
CONSECUTIVE DAYS  
MAXIMUM TEMPERATURE > 95.0 DEGREES F  
  
RANK    #DAYS   END DATE  
  1      36      8/12/2009 (CURRENT ACTIVE STREAK)   
  2      26      9/01/2005  
  3      25      8/04/1998  
  4      20      7/30/2000  
  5      19      8/22/1997  
  6      18      7/06/2009   
  
LOWEST TOTAL PRECIPITATION INCHES  
SEPTEMBER 1ST - AUGUST 11TH  
PERIOD: 345 DAYS  
YEARS: 1888-2009  
  
RANK    VALUE   ENDING DATE  
  1      5.73    7/30/1917  
  2      8.37    7/30/2009 *  
  3      9.85    7/30/1962  
  
EXTREMES  
LOWEST TOTAL PRECIPITATION INCHES  
YEAR TO DATE TOTAL  
YEARS: 1887-2009  
  
RANK    VALUE   ENDING DATE  
  1      3.13    1917  
  2      3.37    1953  
  3      3.65    2009 *  
  
=====================================================================  
  
VICTORIA (PERIOD OF RECORD 1902-2009)  
  
HIGHEST MONTHLY JULY MEAN OF 'DAILY AVERAGE TEMPERATURE' DEGREES F  
  
RANK    VALUE   ENDING DATE  
  1      88.1    2009  
  2      87.2    1998  
  3      87.0    1969  
  
HIGHEST MEAN OF 'DAILY AVERAGE TEMPERATURE' FROM JUNE 1-AUGUST 11  
  
RANK    VALUE   ENDING DATE  
  1      86.6    2009, 1998  
  3      86.0    1953  
  
CONSECUTIVE DAYS  
MAXIMUM TEMPERATURE > 96.0 DEGREES F  
  
RANK   # DAYS    END DATE  
  1      36      8/12/2009 (CURRENT ACTIVE STREAK)  
  2      33      8/15/1912  
  3      31      9/20/1912  
  4      27      8/28/1917, 8/28/1911  
  
DRIEST JANUARY THROUGH JULY PERIOD  
(PERIOD OF RECORD 1893-2009)  
  
1. 6.84  2009  
2. 7.73  1917  
3. 8.52  1925   

Tropical Depression 2 Forms in Atlantic Potential to Become Ana

The second tropical depression of the season formed in the Atlantic early this morning near the Cape Verde Islands. As of 11 am EDT, maximum winds were near 30 mph with some higher gusts. The depression was moving west at 13 mph, and this track is expected to continue for the next couple of days. Some slow strengthening is predicted, and the depression has the potential to become Tropical Storm Ana. However, sea surface temperatures along the track are only marginally warm, and there is drier air in the middle levels of the atmosphere. On the other hand, vertical wind shear is expected to be light for the next several days, which should encourage strengthening.

Image (click to enlarge): Tropical Depression 2 forecast track from National Hurricane Center

Minimally Record Heat Reaches Mid Atlantic

For previous record temperature posts, see:
Record Heat
Record Cold

After a somewhat cool July, near record heat reached the Mid Atlantic area on August 10. The only record set appears to have been for the relatively shorter observation history at Washington Dulles (since 1963):

A RECORD HIGH TEMPERATURE OF 97 DEGREES WAS SET AT WASHINGTON   
DULLES DC TODAY. THIS BREAKS THE OLD RECORD OF 96 SET IN 2001.  

The all-time August record at Dulles is 104° on the 20th in 1983.