Weather

"Talking the Tropics With Mike": Strong wave headed for the Caribbean - Sept. 26th

Sept. 26, 2016 — Strong tropical wave -- 97L -- moves into the Central Atlantic.....

You will hear & see lots of "hubbub" regarding the wave (97L) approaching the Caribbean about the middle of this week.... stay HERE for the "real deal" - just the facts. :) ... models have been, are & will bounce around a lot.  Seems likely that we'll have a system into the Eastern Caribbean by late in the week where what could be "Matthew" will then slow down & reach a crossroads -- to continue west, turn more northwest.... OR take a sharp turn to the north.  The far southern latitude could even bring into play the landmass of S. America which may complicate the intensity forecast even more than usual.

WE'RE JUST A FEW WEEKS PAST THE PEAK MONTH OF THE HURRICANE SEASON...  You should always be prepared & aware.  First Alert Hurricane Center ** here **.  Reminder that flood insurance policies take 30 days to take effect..... & will not be written when/if a named storm is nearby.

The last advisory from the NHC on "Lisa" was issued Sat... the last advisory on "Karl" was issued Sunday.

The band of clouds stretching from Southern Canada to Texas on the satellite imagery below is being driven by a cold front & strong upper level trough of low pressure (see 2nd image below).  This upper trough will settle over the Eastern U.S. by the weekend & could be reinforced by a 2nd upper level trough early next week.  This upper level pattern may be the key for the tropical disturbance that will soon be over the Carribean.

Upper level forecast for late Fri.:

A strong wave -- 97L -- that moved off Africa late last week is at a more southern latitude than past waves & has high potential to develop..... & eventually become "Matthew".  Most of the long range global forecast models latch onto this wave taking the wave quickly into the Caribbean by the middle to end of this week.  Definitely a wave to watch but, of course, still very early in the system's evolution.  Despite the current fast movement, the wave will slow considerably by late week at which point we see some kind of turn more northward.  The key to this wave's track in the long run will likely be a strong mid-latitude trough of low pressure that is forecast to develop over the Lower 48 of the U.S.  This feature may very well draw northward whatever is in the Caribbean.  But if the upper trough is not deep enough (far enough south), the Caribbean tropical disturbance could be missed initially which would mean movement farther to the west.  Caribbean tropical cyclones do have a tendency to thrive in late Sept. - Oct. which adds even more confidence to the forecast of a possible hurricane over the Caribbean in the coming days.

Zoomed in image of 97-L:

Forecast models have certainly trended east recently (after the turn more north) but model flip-flops will remain possible......

Image below courtesy CIMSS & shows the oceanic heat content.  Yellow & orange indicates higher heat content which give tropical cyclones added "energy".....

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Water vapor imagery below shows plenty of moisture pooling over the SW Atlantic/Caribbean & Gulf of Mexico....

The wind shear (red lines represent strongest shear) analysis shows a good deal of shear stretching from the Gulf of Mexico through much of the Caribbean but is gradually shifting a little more west & south.....

A weak upper level low is located west & east of Jacksonville with some convection but no surface development (low pressure) is indicated.  Gulf of Mexico:

East Atlantic where tropical waves continue to march westward.  We're nearing what is typically the end of the "Cape Verde season":

Lots of warm water to help "feed" tropical cyclones.  Water temps. of 28 degrees Celsius equates to 82 degrees Fahrenheit.  Tropical cyclones generally need at least 80 degree water to thrive.

Sea surface temps. vs. average:

In the W. Pacific.... yet another significant typhoon is forming -- "Megi".  The storm is forecast to move over typhoon-wary Taiwan by Tue.

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