Masters student in tropical meteorology at FSU. Raised in Alaskan blizzards, but drawn toward tropical cyclones by their superior PGF.
By: Levi32 , 4:13 PM GMT on June 25, 2009
Tropical Tidbit from 12:00pm EDT Thursday, June 25, 2009:
Turn up the volume, and click HD if quality is too low:
There are a couple areas we need to keep an eye on. First I'll address the situation closest to home. The trough-split I've been talking and warning about is underway over the eastern Gulf of Mexico, and as the piece splits off it will drift SW into the Bay of Campeche over the next 3 days. The old frontal trough still draped across the eastern GOM, southern Florida, and the Bahamas hasn't spawned any organized areas of low pressure, but there is an area of low-level vorticity just SW of Tampa that you can see spinning on satellite imagery. I failed to mention this in the video, but as I said there is nothing really organized and most of the energy is going to start focusing to the south which I will talk about in a moment. Regardless of how it looks right now, surface troughs in the Gulf of Mexico ALWAYS mean trouble, especially with trough-splits, and no matter what we must watch them. The old frontal trough boundary will slowly dissipate over the next few days as the cut-off upper feature backs to the SW.
Now as the upper feature gets into the Bay of Campeche it will start interacting with a new system. There is a mid-to-low-level circulation near the border of Costa Rica and Nicaragua that I have been watching since yesterday. This circulation is going to be moving slowly NW towards the northern coast of Honduras during the next 2 days, then in the vicinity of the Yucatan, and eventually in about 4 days will get drawn up into the Bay of Campeche and southern Gulf of Mexico by the trough-split feature which will be backing SW out of the GOM into Mexico. During this time a tropical wave currently along 77W entering the western Caribbean will be combining with the mid-level circulation, and as this happens the GFS forms a surface low north of Honduras in 48 hours. Due to all the land in the way this is likely not a threat to significantly develop in the Caribbean, but I would watch this very closely as it gets into the Gulf of Mexico because when that trough-split pulls out it's going to get stuck there for several days under weak upper-level winds. If it sits long enough another tropical wave currently approaching the Antilles Islands may pile its energy into the mix as well. I will be watching this area closely for mischief over the next week.
Notice the pattern we have going here. Remember how in early June I talked about this period from the 20th through the 30th where moisture and heat would advect northward from the east Pacific into the western Caribbean and southern Gulf of Mexico. We had that disturbance in the Bay of Campeche a couple days ago. It came north over Mexico from the east Pacific. This disturbance I mentioned in the previous paragraph is also coming north out of the east Pacific where it was last night. Even if nothing develops it's not like there's nothing going on here. You can see the pattern that has developed with the MJO pulse and the big ridge over the southern US. The mean trough off the east coast as I also mentioned in early June is in a pattern prime for trough-splits into the Gulf of Mexico and NW Caribbean, which are one of the main causes of early-season tropical development. It is interesting to see how this is all coming together.
The 2nd area we need to watch is the big wave coming off west Africa. In my last blog I outlined all the pros and cons, and they still stand today. I know there's a lot of threatening-looking convection with this system but don't be surprised if it all falls apart when it moves over water tonight and tomorrow. I'd like to see this over water for 24 hours before I make a judgement on whether it may develop as the GFS has been insisting on. Don't discount it though, we do need to watch this one as it is the strongest wave to come off Africa yet this season.
We shall see what happens!
Caribbean Visible Satellite: (click image for loop)
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