Not in the Clear from Dean

While the official forecast from the National Hurricane Center in Miami, Florida calls for Hurricane Dean to move across the Yucatan Peninsula then into either south Texas or north Mexico, the northern Gulf id by no means in the clear yet. There are several reasons:

1. A trough of low pressure over the Bahamas is forecast to move west, causing a slight weakening of the high pressure over the Lower Mississippi Valley. This could cause Dean to move farther north than forecast.
2. The forecast will not be especially confident until Dean enters the Gulf of Mexico. Models and forecasters do not usually get a good handle on a tropical cyclone until it enters the next body of water. In this case, the Gulf of Mexico. In 2005, Hurricane Katrina was originally forecast to make landfall on the Florida Panhandle but instead made landfall near 250 miles west at the Louisiana-Mississippi border.
3. Hurricane forecasts for days 3 - 5 are HISTORICALLY to far to the west. In 2005, Hurricane Rita was originally supposed to make landfall near Port O'Connor, Texas but instead made landfall at the Louisiana-Texas border. In 2006, Tropical Storm Ernesto was originally forecast to make landfall in Mississippi or Alabama but instead made landfall on the southern tip of Florida as it moved north-northeastwards.
4. Tropical cyclone forecasts for days 3 - 5 can have very large errors. According to the National Hurricane Center, the average error for day three forecasts is 205 miles, 290 miles for day four, and 375 miles for day five. For perspective 300 miles is roughly the distance from Baton Rouge, LA to Houston, TX. This means that if for example a hurricane was forecast to landfall near Grand Isle, LA, it could very well end up as far west as Galveston, Texas or as far east as Destin, Florida.

The best advice I can give Gulf Coast residents is to continue monitoring Dean and go over your disaster and evacuation plans.

NOAA Lowers its 2007 Hurricane Forecast

The National Oceanic and Atmospheric Administration (NOAA), has reduced its predictions for the number of hurricanes for this year. The new prediction calls for 15 named storms, 8 hurricanes, and 4 major hurricanes. A major hurricane is one with category three intensity or higher. This forecast is down from the previous forecast with 17 named storms, 10 hurricanes, and 5 major hurricanes. The average numbers between 1950 and 2000 are 10 named storms, 6 hurricanes, and 2 major hurricanes each season.

So far this year we have seen three named storms:

• Subtropical Storm Andrea: a weak subtropical storm that formed on May 9 that meandered off the coast of Florida producing high winds and seas over the Atlantic Ocean between Virginia and Florida.
• Tropical Storm Barry: a moderate tropical storms that formed on June 1 and made landfall near Tampa, Florida as a weakening tropical depression. The remnants of Barry killed one person Pinellas County near Saint Petersburg, Florida.
• Tropical Storm Chantal: a weak tropical storm that formed between Bermuda and Cape Cod, Massachusetts that rapidly became a powerful extratropical cyclone as it moved over the Atlantic Canadian provinces.

Last year we saw 10 named storms, 5 hurricanes, and 2 major hurricanes. The strongest storms were Hurricanes Gordon and Helene which both reached a peak intensity of 120 MPH winds (category three) over the open waters of the Atlantic. The most significant storm to affect the United States was Hurricane Ernesto which made landfall at Plantation Key, Florida with 45 MPH winds. The storm caused minor damage in Florida. The storm made a second landfall at Oak Island, North Carolina as a strong tropical storm with 70 MPH winds. In the mid-Atlantic states, Ernesto caused four deaths and about $500 million in damages.

Remember that an active season is still anticipated and the bulk of activity does not generally get started until mid-August and lasts through late September. Also remember that it only takes one storm to have a bad season. In 1992, there were only 6 named storms and 1 major hurricane. That major hurricane was Category Five Hurricane Andrew which devastated large areas of the Miami Metropolitan Area and remained the most destructive hurricane in history until Hurricane Katrina in 2005 broke its record.

July 2007 Weather Review

Here area the statistics from Jason's Weather Station for the month of July.

• Average Temperature: 81 (-1 from normal)
• Highest Temperature: 97 at 3:20 PM on the 18th (record: 107 on July 13, 1901)
  
• Lowest Temperature: 67 at 5:50 AM on the 24th (record: 57 on July 7, 1924)
  
• Heating Degree Days: 0
• Cooling Degree Days: 479 (90% of average)
  
• Rainfall: 5.64 inches (85% of average)
• Rainiest Day: 1.39 inches on the 20th (record: 5.66 inches on July 29, 1954 during Tropical Storm Barbara)
• Highest Wind Gust: 19 MPH from the south at 5:00 AM on the 15th
• Days where temperature exceeded 90: 21
• Days where rainfall was measured: 16
• Days where rainfall exceeded 0.10 inch: 11
• Days where rainfall exceeded 1.00 inch: 1

The statistics show that Lafayette (where the station is) experienced slightly cooler temperatures and slightly drier conditions than normal. The cooling degree days for July of 2007 was 479 which is only 90% of normal. The rainfall was 5.64 inches which is only 85% of normal. While to most it may seem that July was very wet, this is because 16 days, rainfall was recorded, this is over half of the days in the month of July.

Based on long term climate forecasts, for the month of August, we can expect near normal conditions with slightly cooler and wetter conditions possible across the western third of the state.

During July, we saw one tropical system; Tropical Storm Chantal which formed on July 31 and rapidly became extratropical as it moved northeastwards without affecting land.