Thursday, August 23, 2012

8/23 - 5pm - Tropics, Drought, Storms... Anything Else?

Computer model forecast tracks for Isaac
The big shakeup in the world of weather right now is the presence of Tropical Storm Isaac south of Puerto Rico. Much uncertainty still exists with where the storm will go but certainty of it making some sort of US landfall is growing. Current forecast data from multiple computer models has this storm going anywhere from the eastern Florida Peninsula to the Central Gulf over the coming days. The trend has been for these forecast tracks to shift westward over the past couple days and that means that those with interests along the Gulf Coast need to watch this storm extremely carefully. The fact that this storm may miss most of Hispanola and it's rough terrain means that we could have a stronger storm than previously expected by the time it reaches the Gulf. Once we get some better data tonight from a NOAA Gulfstream IV aircraft that is being dispatched to take measurements of the storm the model data and forecasts should improve a bit.

The 5pm EDT National Hurricane Center update on Isaac has again taken a more westerly track than before thanks to the latest model data. Their forecast has Isaac remaining a tropical storm until it clears the north side of Cuba on Monday and becomes a hurricane. This all depends on where the storm tracks because the less of Cuba and Hispanola it goes over, the more time over warm water it will have. Should the storm remain weak like it is now for a longer period, a more westerly track can be expected.

How 'bout the drought? Not much has changed from last week's drought monitor product for West Tennessee and North Mississippi. Much of West Tennessee is still suffering from a severe to exceptional drought, especially in areas near the Mississippi River and Kentucky border. The area of exceptional drought, the highest level possible, has contracted a bit since last week. Areas south of Benton County and east of Bolivar aren't faring as badly as the rest of West Tennessee, but it's worth noting that rain may be hard to come by over the next week. The worst of North Mississippi's drought is still confined to areas near Tunica and areas south of West Point don't have drought conditions at this time.

Speaking of rain, we're looking at just a small chance for some isolated showers and storms on Saturday afternoon in North Mississippi as an upper-level system moves toward us from the west. This will increase our moisture and instability a touch since winds will be turning more southerly at the surface. West Tennessee will be too far north for this storm chance unfortunately. Small storm chances will be in the forecast again as we head into the early part of the workweek, but uncertainly skyrockets after that because our weather will depend on where Isaac, by then likely a hurricane, will go. A more westerly landfall along the Gulf Coast would mean quite a bit of rain for the region while a more easterly landfall in Florida wouldn't affect us too much. This again is something we'll need to watch.

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