A Look at Summer 2009 and the Tropics
It is time to look forward to vacations, picnics, bar-b-ques, swimming and lemonade as we head into the summer months of June, July and August. But what does Mother Nature have in store for us this year? Will it be sweltering, typical or unusually chilly? We will attempt to answer those questions for you in this year’s 2009 Summer Outlook. In addition, we will take a look into the tropics and provide you with a outlook on the tropical weather season.
First, lets start by reviewing the basic information gathered and utilized to help create this year’s summer outlook. As is the case with every long range outlook, there are many variables that are brought together like pieces of a puzzle to help create a picture. Unfortunately, if just one variable changes significantly the whole seasonal outlook can be put into jeopardy. A few of these variables include Pacific equatorial water temperatures, north Pacific water temperatures, north Atlantic water temperatures and pressure trends and recent rainfall trends over the past several weeks and months.
One of the major factors in a long range seasonal outlook is El Nino vs. El Nina. A look at water temperatures in the tropical region of the Pacific ocean reveals that neutral conditions are forecast to transition to a moderate El Nino. Five consecutive months of gradual warming of the waters in this region is anticipated to continue through the summer and by August it is likely that we will be averaging about 1 degree above normal across the interested area marking a moderate El Nino. El Nino impacts during the summer across the TN Valley include: drier than normal, bit cooler than normal and usually provides a less conducive environment for hurricanes and tropical storms to develop.
Reviewing previous monthly data across the tropical Pacific, the north Atlantic water temperature and pressure trends and previous monthly temperature and precipitation trends across the TN Valley has helped in providing reference years to look back at as possible solutions to the upcoming 2009 summer and tropical season. The years referenced were 2006, 2001, 1976, 1974, 1968 and 1965. Using these years, the current recent weather trends and forecast data the following summer and tropical outlook as been comprised.
June 2009
June will finally allow the TN Valley to dry out after the 3rd wettest May on record, while being a bit cooler than normal. A few days of severe weather are also possible, but mainly anticipating a few strong storms with gusty winds and some hail to briefly become severe.
July 2009
July is traditionally the hottest month during the entire year for the TN Valley, and I believe this year will not be any different. However, I do believe this July will be cooler than normal with no days making it to the century mark. Rainfall will be near average and a few days of severe weather is possible similar to that in June.
August 2009
August will provide the last chance for seeing above normal heat across the TN Valley for this summer, but again like June, and July it appears that even though a few days may be quite warm overall; the month will average on the cooler side of normal. It will also mark a continuation of a drying out across the Valley after the wet Spring we had.
A Look at the Tropics
June 1st officially started the 2009 Hurricane Season even though the tropics had already tried to provide the season’s first tropical system, twice. Before providing you the official Storm Force 31 tropical outlook I thought it would be good to provide some comparison outlooks from a couple other major sources.
The National Hurricane Center’s (NHC) outlook for the season calls for a near normal Atlantic hurricane season. But what does that mean and what are their specifics? On average, the tropical season in the Atlantic includes 10 named storms with 6 becoming hurricanes and of those 3 becoming “Major” hurricanes. Their outlook calls for a 70% chance of 9 to 14 named storms with 4 to 7 of them becoming hurricanes and of those 3 reaching “Major” status, category 3, 4 or 5. The NHC’s hurricane outlook doesn’t provide specifics on potential landfall.
Another popular source for hurricane outlooks is the one provided by Colorado State University professor, Dr. William Gray. His 2009 outlook also calls for an average Atlantic hurricane season. The outlook forecasts 12 named storms with 6 being hurricanes and 2 of those reaching “Major” hurricane status. It also forecasts normal chances for U.S. Landfall of a “Major” hurricane, 54%.
Now, the official Storm Force 31 tropical outlook. Like the NHC and Dr. Gray, the Storm Force 31 outlook also forecasts a near normal tropical season. We predict 9 named storms with one storm becoming a “Major” hurricane. We are also forecasting 4 named storms making a U.S. Landfall with the highest probability being along the Eastern Gulf of Mexico coast in Florida northward up the Atlantic Coast from Eastern FL to the DELMARVA.
And A Look Back at Spring 2009
Taking a look back at Spring 2009 we can say it was definitely wet. Both April and May had above normal rainfall with May 2009 becoming the 3rd wettest May ever. So how did the Storm Force 31 Spring 2009 Outlook measure up? Here is a table that shows you the forecast and what actually happened. You decide how we did and let us know what our grade was.
April 2009
Forecast: (Actual)
Temperature: Slightly Above Normal (0.2 Degrees Above Normal)
80 Degree Days: 10 (8)
Precipitation: Near Normal (1.26″ Above Normal)
Severe Days: 4 (6)
May 2009
Forecast: (Actual)
Temperature: Slightly Above Normal (1.1 Degrees Above Normal)
90 Degree Days: 3 (1)
Precipitation: Near Normal (4.96″ Above Normal)
Severe Days: 5 (8)
Dale Bader / Meteorologist, Storm Force 31
