Invest 97-L Located Over The Eastern Atlantic: It appears that Invest 97-L is extremely close to becoming a depression today & in fact, it would not surprise me to see the National Hurricane Center upgrade it to a Tropical Depression at 11 am EDT today.
NOTE – Just as I was finishing writing today’s discussion, I received a message from NHC saying that this system is being upgraded to Tropical Storm Erin at 11 am EDT.
A look at satellite imagery reveals that the shower and thunderstorm activity associated with Invest 97-L is looking pretty healthy & concentrated. Further analysis reveals that Invest 97-L may be producing up to 40 mph maximum winds, based on satellite data. If this is the case, then NHC may end up skipping the depression designation & immediately upgrading it to a tropical storm.
Analysis of the environment around Invest 97-L indicates that this system is being impacted by easterly wind shear & this, combined with cooler ocean water temperatures, should put a limit on how much it strengthens over the next 2 to 3 days or so.
Beyond this, the environmental conditions become much more favorable for strengthening towards the end of this week & because of this, I fully expect this system to be our first hurricane of the season.
Model Guidance: The overall model guidance are in really good agreement with their forecasts of the track of Invest 97-L. They seem to strongly suggest that this system will turn back to the west by Tuesday and head in a westerly direction through Wednesday into Thursday.
From there, guidance is still in very good agreement in showing this system turning a little more to the west-northwest and passing very safely to the north of the Leeward Islands and the Virgin Islands by Saturday.
Looking beyond this, the model guidance seems to suggest that a weakness will develop between a high pressure ridge over the Gulf and another high pressure ridge over Africa. This weakness should help to steer this system, likely Hurricane Erin at that point, to turn much more to the northwest. Usually from here, these storms will continue turning to the north and track out into the open Atlantic & probably threatening Bermuda along the way. More than likely, this will probably actually occur.
That said, there is some uncertainty in the guidance on whether the Gulf high pressure tries to build eastward and bridge the gap with the high pressure ridge over the central and eastern Atlantic. If there is any bridging in that weakness in the high pressure ridge, it could cause this system to try to track closer to the Bahamas, the East Coast of the United States and Atlantic Canada.
Here Are My Thoughts: It looks more likely than not that the environmental conditions around this system will favor strengthening throughout this week. Because of this, it looks likely that this system will be a hurricane by the end of this week.
I also think that it’s pretty likely that Invest 97-L will pass very safely to the north of the Leeward Islands and the Virgin Islands by about Saturday & because of this, I think that there isn’t anything to be concerned about in terms of impacts for the eastern and northeastern Caribbean from this system, except for swells later this week through this weekend.
Looking further down the road, I think we may still be a few more days away from absolutely ruling out a direct impact to the East Coast of the United States or Atlantic Canada. The reason why is because there is uncertainty as to how sharp of a turn to the northwest and north will occur with this system.
Because of this, there are a couple of scenarios that could play out next week with this system:
The first scenario is for the weakness in the western Atlantic to be strong enough to turn this system northward and northeastward sparing the East Coast of the United States and Atlantic Canada from a direct hit. In this scenario, Bermuda could very well be threatened, if not impacted as this system turns to the north and northeast.
The second scenario is for the upper level high pressure ridge to build back in and steer this system towards the East Coast of the United States and Atlantic Canada.
My feeling as of right now is that future Hurricane Erin should ultimately head out into the open Atlantic and not be a threat to the US East Coast. That said, Bermuda and Atlantic Canada definitely needs to keep close tabs on how sharp the north and northeast turn is next week as many guidance members do point to a threat to Bermuda and then to Nova Scotia and Newfoundland.
The Bottom Line Is That the trends for a hit on the East Coast of the United States and the Bahamas are decreasing. That said, I want to give it a couple of more days until I can absolutely assure you that the US East Coast is safe from future Erin.
Model Track Forecast:
Satellite Imagery:
What Else Is Behind Invest 97-L: A look at satellite imagery of what’s behind Invest 97-L/Erin shows that there is another wave right on the coast of western Africa. This wave may have some chance to develop as it heads westward across the Atlantic. It should be noted that only the AI models are showing development of this wave, with other models such as the GFS and European models showing no development at all. I am skeptical of using the AI models as they haven’t done very well this season in their forecasts of development.
For now, it’s a wave to just keep an eye on, but I’m not urgently concerned that it’ll develop anytime soon.
The next tropical weather discussion will be issued on Tuesday.