August 25, 2008

I have been asked by several people lately what we can expect for autumn of 2008.

First, a brief history lesson: The fall of 2007 was very dry and quite warm. The flooding rains of summer abruptly transitioned into a four-month drought from August to November. It was awful!

One of the driving forces for this was a fairly strong La Nina. This pattern tends to shift the jet stream further east leaving the southern Plains with a dry northwesterly flow beneath an upper ridge: not a favorable set-up for rain in these parts.

The La Nina has fizzled in the past few months, leaving us in a “neutral” situation. This means that neither a La Nina nor an El Nino is currently in progress.  The statistics since 1980 reveal dry autumns during several neutral years, such as in 2005, 2003, 1990 and 1989, while there are also a number of instances with very heavy rain events during neutral years. Examples in the months October or November include 1996 (over 13” of rain in November), and 1984 (over 10” of rain in October).

Thus, the odds are that we’ll have a fairly average fall precipitation season, but this may be punctuated by one or more heavy rain events if things trend wetter.  September and October are usually rainy months here, with October the 2^nd wettest (on average) of the year and September the 4^th wettest (the last half of September gets most of the rain for the month).

The Climate Prediction Center has also issued a fall forecast. We both agree on the rainfall, they go on to suggest we can expect above normal temperatures as well.  I am led to believe that this is also too close to call.

So, my autumn 2008 forecast for Texoma is for near normal rainfall and temperatures.

I will post an updated fall outlook towards the end of September.

As always, time will tell!

Take Care,

Steve LaNore

Chief Meteorologist

 KXII-TV