97L growing more organized, will bring heavy rain to the Lesser Antilles
The tropical wave near 12N 52W, about 600 miles east of the Lesser Antilles Islands (97 L), has grown more organized this morning as it tracks west at about 20 mph. This wave is surrounded by an area of very dry air from the Sahara Desert, but 97L has been able to steadily moisten a large region of the atmosphere over the past day, insulating itself from the dry air. This moistening process has been aided by sea surface temperatures (SSTs) that have steadily increased from 26.5°C to 27.5°C, plus the presence of only 10 knots of wind shear. The system now has a small area of intense thunderstorms near its center, with some rotation of the cloud pattern evident at mid-levels of the atmosphere. An upper-level outflow channel has opened to the north, and there is evidence that surface spiral bands are beginning to form. This morning's QuikSCAT pass missed 97L, so we don't know what is happening at the surface.
Wind shear is a modest 10 knots over the disturbance, and is forecast to remain in the moderate 10 - 15 knot range through Monday morning. This should allow further development to occur today, and 97L could be approaching tropical depression strength on Monday as it moves through the central Lesser Antilles Islands. Monday night, shear is expected to rise to 20 - 30 knots, thanks to the presence of a trough of low pressure at upper levels of the atmosphere over the eastern Caribbean. Since 97L is a relatively small system, it is very vulnerable to wind shear. This shear may be able to drive some of the dry air west of 97L deep into its interior, significantly disrupting the disturbance. Shear will remain high along 97L's path through Thursday, when the storm should be in the western Caribbean near Cuba. If there is anything left of 97L by then, some development is possible. The National Hurricane Center gave 97L a low (less than 30% chance) of developing into a tropical depression in the next 48 hours in their 8am Tropical Weather Outlook. However, I'd say the odds are now in the medium range (30 - 50%).
None of the computer models are forecasting tropical storm development over the next seven days.
Figure 1. Current satellite image of African wave 97L.
I'll have an update Monday morning. As 97L approaches the islands, you may want to follow local observations there using our wundermap for 97L.
Jeff Masters
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Substantial thunderstorm activity will increase tonight, and this might help form a central dense overcast (CDO), which would support the formation of a sufficiently closed LLC. Nevertheless, wind shear should not adequately slacken in time for significant coalescence, because mean shear should approximately be 20kts, which is mostly unfavorable, but not so unfavorable to induce a Robespierre effect. Once it passes through the Lesser Antilles, then it will have to be watch for development, as the TUTT rapidly lifts and replaced with the STR, producing ventilation for tropical cyclogenesis.
due to the impending shear, still a good choice to keep it at yellow
In the month long animations I've made in the past, you can see this happening over and over again. The head gets ripped off, but the wave persists and continues its movement...and then BAM! There ya go...cyclonic activity.
Hmmm ... no longer tonight but in 24 to 48hrs time. Why the sudden change of thinking.
Hmmm StormW I see you are avoiding the above post... as i wasn't around when that happen, wait, i probably dont wanna know lol.
Might have to do with the latest GFS shear model showing shear more favorable than it did in previous runs
HWRF showed 94L becoming a CAT3 hitting FL, so I don't know what makes it so special now lol
Hes a liar and a troll. You really should ignore him.
Seems rather reasonable. Only time will tell.
JSC ch.
UPPER-LEVEL WINDS ARE EXPECTED TO
BECOME LESS FAVORABLE FOR THE DEVELOPMENT OF THIS SYSTEM OVER THE
NEXT 24 TO 48 HOURS.
previously it was:
UPPER-LEVEL WINDS ARE EXPECTED TO
BECOME LESS FAVORABLE FOR THE DEVELOPMENT OF THIS SYSTEM LATER TONIGHT.
Would one of you experts be so kind as to give me a quick update on the near term tropical weather outlook? And remember: please keep it no more complex than about a third grade level...
Water vapor imagery shows 97L is nearing the periphery of the open upper level ridge that has been protecting it. An anticyclone cannot protect a system from an advancing upper level trough.
Its called weather for a reason
with scattered Heat..
dat bout it press
Ok, I gotta hear more about this one...
Going to watch the ESPY's :)
Not tonight...just monitoring. I generally as a rule don't post on the weekends, especially Sunday, unless we have something going on or an immediate threat to the Islands or CONUS.
my bad...will sure remember....
No wonder we (the ones who are in learning mode) can't keep up and get confused. They seem to be confused too lol.
I suffered from the "Peppermint Schnapps effect" once.
Was a lotta spin to it too.
ill bet if they said 24-48 hours previously when it looked good, they would have upped it to code orange.
they are much more inconsistent, dependent among other sources, and conservative this year than any other it seems.
Viewer Discretion is advised.... You are about to witness the goring illustration of a beheaded tropical cyclone.
Image credits to Cyberteddy
In other words SPLAT!! lol
Quoting Weather456:
lol I can't remember the blog being this funny, and the NHC being this inconsistent.97L is one for the books. Every time the GFS changes we get a change in the TWO:
UPPER-LEVEL WINDS ARE EXPECTED TO
BECOME LESS FAVORABLE FOR THE DEVELOPMENT OF THIS SYSTEM OVER THE
NEXT 24 TO 48 HOURS.
previously it was:
UPPER-LEVEL WINDS ARE EXPECTED TO
BECOME LESS FAVORABLE FOR THE DEVELOPMENT OF THIS SYSTEM LATER TONIGHT.
ill bet if they said 24-48 hours previously when it looked good, they would have upped it to code orange.
they are much more inconsistent, dependent among other sources, and conservative this year than any other it seems.
probably because the Gov't has taken over how and when to respond to storms now, hell why not they are taken over everything else...so if it's like the tele-promptors that keep malfunctioning or when Bieden pops off about something he shouldn't have said...we might never know if or when they will decide to inform us...lol..
just a ponder...
Most of us just say "shear" and leave out references to tyrants of the French Revolution.
No one really knows when one of these "critters" may surprise you!
I wont call 97L dead untill it is gone. I watch closely!
Some of you here offer very good info that helps people learn. Thanks!
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