14 June 2021

Watching two features of interest, one with U.S. impacts

Monday morning's enhanced infrared satellite image with the two features of interest marked with Xs. The orange blobs define the region in which NHC suspects each of them could form within the next five days (both have a 50% probability).

It is only June 14, but there's a small chance of reaching the second and third tropical cyclones of the Atlantic hurricane season already.  The first feature of interest is a very slowly-evolving broad area of circulation in the Bay of Campeche (southern Gulf of Mexico) which has been festering and organizing for over a week already.  Tagged as "Invest 92L"*, it is going to ooze northward toward Texas and Louisiana over the next 5-6 days.

[* Invest is a term given to an area of interest, such systems get recycled numbers from 90-99 throughout the season, and L refers to the atLantic.  So, 92 is the third such invest of the season, and there will be several other 92Ls in the coming months.  They only receive a unique number once they have undergone genesis and reached tropical depression status.]

Even if it never becomes a tropical cyclone, it will still bring very heavy rain to the storm-weary and saturated northern Gulf coast on Friday-Sunday.  If it does develop, then add some wind to that rain -- but water is the big story.

Rainfall outlook over the next seven days.

As is typically the case with these large and diffuse systems, its future is especially uncertain.  Models have a difficult time pin-pointing when it will consolidate (if ever), and that timing affects the track, which affects the intensity. The map below shows tracks from the European model's ensemble out to Saturday evening.  Other models show similar messiness. Don't worry about an exact track anyway, the rain will cover a big area, as the map above suggests.

While 92L may still take a few days to get organized, Invest 93L is very close to being a tropical cyclone.  It is a low pressure system embedded in the tail end of a long cold front and is centered just east of North Carolina.  It is moving away from the coast and will just bring some chances of stormy weather to the Outer Banks today.  It has just a short window to do anything though; as it zips off to the northeast it will quickly encounter cold ocean temperatures by mid-week.

3.5-hour radar loop of 93L just east of the Outer Banks.

Should they both end up getting named, the system by North Carolina would be first (possibly today??), and the next two names on this year's list are Bill and Claudette.

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