It is officially TROPICAL STORM IDA as hurricane hunter aircraft are flying a mission in the low pressure system right now.
Since we now have the actual location of an actual low pressure center for the tropical cyclone to input into the models predictions can begin to move beyond mere speculation on its future, but it is still poorly organized so we have to temper confidence until it gets itself together more.
Let me provide some “inside Baseball” or an “under the hood” look at what meteorologists are looking at, the meteorology behind the forecast concerns:
IDA seems to have everything going for it (at least in observations and modeling projections for the future) to organize quickly and strengthen into a strong if not major hurricane.
WHAT ARE THOSE FAVORABLE FACTORS?:
* MJO in favorable phase 2
* Strong positive mid and upper-level outflow above the system to vent it aloft (upper divergence = low level convergence)
* Lots of tropical moisture WITHOUT nearby dry air or dust
* More than warm enough sea-surface temperatures (~30C) and deep layer of warm water for high-octane fuel based on ocean heat content (OHC) values 100-150+, expected path over highest readings in the whole Gulf/Caribbean basin
* Very warm Gulf Loop Current and deep warm eddy/pool Southeast of Louisiana ahead of forecast path (can sometimes serve as turbo-charger)
* Lack of wind shear, wind shear too low to inhibit development or cause weakening
* No apparent threat of an inland front or mid-level trough coming at the system as it nears land as it is steered around the pin-wheel of the Bermuda high the only trough is in the upper Midwest/Canada
* Sufficient time over open water expected after land interaction with Cuba
So the coupled ocean-atmosphere set-up looks primed for rapid intensification of IDA although it is not guaranteed.
I do not currently have any significant qualms with what the official NHC forecast is showing. HOWEVER, the circulation of the system is still pretty weak so we have a long way to go and future shifts in track and intensity changes would be no surprise. Confidence would be higher IF we had a better well-defined center.
So while a Louisiana coast hit is AT PRESENT the most probable, an East TX or MS/AL coast can’t be ruled out just yet.
Nothing is set in stone with the storm around 3 days away from the U.S. a lot can and probably will change. The NHC has already nudged the track a bit farther East with each update, and storms this season have moved faster than predicted, maybe that happens here and there ends up less time for strengthening?
A. Tropical storms and hurricanes are more than the wind, in fact water is the #1 killer.
B. Significant impacts occur throughout the “cone of uncertainty” and WELL OUTSIDE the cone.
C. These storms are not dots or a single track line on a map, they can be hundreds of miles in diameter (size of multiple states).
D. The media and public focus way too much on what “category” a storm is, what the “max wind is” when in fact the wind category classification ONLY pertains to near the eye or center of the low pressure which is a mere fraction of the total size of the storm, maybe 5-15 miles ultimately affecting far fewer people and much less land than the rest of the storm! So it’s foolish to chase that landfall point, instead focus on the impacts being forecast for various locations on the coast and inland.
I filled up my car with gas today, I was running low anyway and I know the companies use any excuse to jack up prices. Even if the system weakens or swerves disruption is possible even if just from safety precaution shut-downs and evacuations of rigs and refineries.
Any impact on Metro Atlanta weather is many days away and Christina Edwards has your 5-Day forecast covered.
For more follow me on Twitter @MellishMeterWSB
©2021 Cox Media Group