Monday, June 12, 2017

Convoluted Weather Pattern...

While I was working, one of the biggest things to bug me was not being able to clearly define why our weather was doing what it was doing.   Most of the time it was easy…cold front triggering showers, sea breeze front triggering showers, daytime heating triggering showers, upper level low triggering showers yada, yada, yada.   However, it was days like today that baffled me.  For instance, yesterday’s weak upper low near Lake Charles is even less defines as a broad upper low that has drifted just to the SE of the mouth of the river.  More baffling is some kind of “shear zone” that is clearly seen on the water vapor loop stretching from east Texas southward down into the Bay of Campeche.  West of that line it’s dry while to its east are numerous showers and T-Storms.  It appears to be almost stationary meaning we will likely see another day of “above normal” rain coverage on Tuesday.  Surface pressures are not falling and seas are not increasing so I guess the ill-defined broad upper low is the culprit for all of our showers today.    The Atlantic Ridge extends westward from Bermuda giving us a deep SE flow of moisture at lower levels.  With Dew points into the mid to upper 70s, any showers that develop are highly efficient in producing tropical downpours.  Models are indicating a drying trend should develop by Wednesday lasting into the weekend.   That doesn’t mean no rain, rather far fewer daily storms.

 

Speaking of the models…they are still hinting at some kind of tropical system developing early next week over the Yucatan & southern Gulf.  With the MJO going into the favorable (rising air) mode, it would not surprise me to see something forming for us to track.   Early signs favor southern Texas/Mexican coasts for the main impacts, but it’s way too early to get concerned since nothing is there yet.   David showed a moisture product (precipitable water) that brought what he called a “Tropical Wave” into the southern Gulf.   That’s all it might be.  We get on average 70-100 tropical waves moving across the Atlantic/Caribbean/Gulf each hurricane season.   Typically only 5-10% of them develop into storms.   Stay tuned!

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