Invest 98L Looks To Be Named Grace
More than 90,000 fan will pack Tiger Stadium in Baton Rouge today for the second LSU home game. Louisiana, Alabama and Mississippi have had heavy downpours off and on all week. Currently, Birmingham Alabama has flash flood warnings. Watch Birmingham’s forecast to find out about the heavy rains, and Baton Rouge’s forecast to find out about tailgating at Louisiana State Unversity.
Invest 98L looks like it will develop into Tropical Storm Grace this weekend. Click below to read more!
Invest 98L (courtesy NOAA) Click Image to Enlarge
The area of showers and thunderstorms called Invest 98L looked impressive last night on satellite imagery, and right now it’s in an area of warm water and low wind shear. Here’s the thing. Strong upper level troughs have been developing across the United States this year. It’s led to a cool summer across portions of the midsection of the country and the Eastern United States. These same troughs have been steering hurricanes away from the United States this year.
Upper Level Trough (courtesy Unisys Weather)
This is what an upper level trough looks like. I’ve drawn a couple of lines in red to make them stand out. On an upper level weather chart, they look like valleys in a mountain range. I think that’s the way they describe them in weather class. There are ridges (mountains) and troughs (valleys). See how the one trough is located over the Northeastern United States. (Ignore the yellows and reds on the map. ) Well, that’s bringing cooler weather to New York, Philadelphia and all the states north of there. The high temperature in New York today is expected to be 70 degrees. These same troughs steer tropical systems once the get close to the United States. This year, because the troughs are so strong, they’ve been steering these tropical systems away from the United States, and into the middle or even far eastern Atlantic. Usually during the summertime, these troughs are very weak, and if they do form, it creates a weakness in the ridge (or mountain) that’s been protecting us from a tropical system. Basically, hurricanes follow the path of least resistance between these ridges and troughs. See how there’s another trough forming across the Pacific Coast? This one will continue its eastward trek toward the middle of the country, and by next week, if Grace becomes a tropical system, it will steer it away from the US coast. This is what TV Weathercasters are talking about when they say the storm is being steered “toward” you or “away” from you.
Dawn Brown