Potentially dangerous 92L steadily developing; Igor nears hurricane strength
A tropical disturbance (92L) over the Eastern Caribbean, a few hundred miles south of Puerto Rico, is steadily organizing and appears likely to develop into a tropical depression by tonight or Sunday morning. Satellite loops show an impressive and expanding region of heavy thunderstorms, with good spiral banding and respectable upper-level outflow on all sides. Long range radar out of Puerto Rico shows that heavy rains are now affecting that island, but there is no rotation to the radar echoes evident. However, the rain bands are becoming more intense and more organized. San Juan, Puerto Rico reported a heavy rain squall at 8:44 am this morning, and radar estimates suggest two inches of rain fell in this squall just southeast of San Juan. Wind shear over 92L is low, 5 - 10 knots. The waters beneath are at near-record warmth, 30°C, and these warm waters extend to great depth. Water vapor satellite loops show a large area of dry air lies to the north and west of 92L, and this dry air could interfere with development at times over the next few days.
Figure 1. Morning satellite image of 92L.
Track forecast for 92L
The disturbance is moving west-northwest at 11 mph, and steering currents favor a continuation of this motion for the next three days. Model support for development is scattered. The GFS and NOGAPS models do not develop 92L. The GFDL and ECMWF models predict development, with a track taking 92L into Mexico's Yucatan Peninsula on Wednesday. The HWRF model has a more northwesterly track, taking 92L over the Dominican Republic, Haiti, and Cuba, but this model has been trending too far north in its tracks. I expect 92L will follow a path south of the islands, bringing it near or just south of Jamaica on Monday, then into the Yucatan Peninsula on Wednesday. On this track, the southern Dominican Republic can expect heavy rains of 3 - 6 inches tonight through Monday morning; southern Haiti can expect similar rains Sunday through Monday, and Jamaica and the Cayman Islands can expect heavier rains of 4 - 8 inches Monday and Tuesday. Eastern Cuba will probably escape 92L's heaviest rains in this scenario (Figure 2.)
Intensity forecast for 92L
I can't find any reason to doubt this will be a tropical storm by Sunday or Monday, and potentially a Category 1 or 2 hurricane by Wednesday, if 92L avoids passage over Hispaniola and Cuba. The SHIPS model predicts wind shear will remain low, 5 - 10 knots, through the period, and makes 92L a Category 1 hurricane by Monday night. Water temperatures are certainly warm enough to support development. The main detriment to intensification is likely to be dry air, and 92L could wrap in some of the dry air to its northwest at times, slowing down development. The first Air Force Hurricane Hunter mission into 92L is scheduled for Sunday afternoon, but there will be a research mission by the National Center for Atmospheric Research G-V jet today that will give us valuable information on 92L's large scale environment and potential for development.
Figure 2. Forecast rain amounts from 92L from the 2am EDT Saturday run of the GFDL model. This model predicts most of 92L's heaviest rains will miss Haiti, but will affect Jamaica, the Cayman Islands, and the Yucatan Peninsula. Image credit: Morris Bender, NOAA/GFDL.
Igor
Tropical Storm Igor is very close to hurricane strength, and appears destined to become a large and powerful major hurricane over the Central Atlantic in the days to come. Wind shear is moderate, 15 - 20 knots, waters are warm, 28°C, and Igor has moistened its environment enough to keep the dry air of the Saharan Air Layer (SAL) at bay. Igor will track west under the influence of a strong ridge of high pressure for the next three days, then turn more to the west-northwest in response to the steering influence of a broad trough of low pressure moving across the Western Atlantic on Tuesday and Wednesday. This should allow Igor to pass several hundred miles to the northeast of the Lesser Antilles. In the longer range, Igor may be a threat to Bermuda, and has a slight chance of making landfall on the U.S. East Coast or Canada. Climatology shows that about 10% of all tropical cyclones that have existed at Igor's current position have gone on to hit the U.S. East Coast; these odds are about 10% for Bermuda and 5% for Canada. The forecast steering pattern for the coming two weeks from the GFS model shows a continuation of the pattern we've seen all hurricane season, with regular strong troughs of low pressure moving off the U.S. East Coast. This pattern favors Igor eventually recurving out to sea without affecting any land areas. The odds of Igor hitting land in the U.S. or Canada are probably close to their climatological 10% and 5% probabilities, respectively.
Elsewhere in the tropics
A new tropical wave (Invest 93L) emerged from the coast of Africa yesterday, and is already showing signs of organization. Most of the models predict 93L will develop into a tropical depression 2 - 4 days from now, and NHC is giving 93L a 30% chance of developing by Monday.
Next post
This may be my only post today; I'll have a new post Sunday morning.
Jeff Masters
Reader Comments
Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 — Blog Index
ATL WV Loop
The guy who actually forecasted that "Perfect Storm" out of Boston WS was Dr. Bob Case. He was a forecaster at the NHC back in the 80's. A real nice guy, who also took a liking to a very young Avilla at the time, often commenting "he really knows his stuff. It looks like he was right.
Correct. The US will be hit eventually. I'm no wishcaster, but the chances are quite high that something will eventually find US soil. Hermine already did so.
Thanks for posting that link on lightening and storm intensity corrolation.
Very interesting.
Here's a link for another phenomenom you may like.
It's from Scientific American
Link
Yep, Beell, we're on the same page. The weakness is closing, not as pronounced. And, it only takes eyeballs to see 92L react quickly to the low-level flow, shooting it westwards.
It's alright, Levi, you do really good. But, all of these dynamics can sometimes fool the best of us, least of which is me. Oh, and yes, good luck on your studies - all the best!
Just curious, is English your first/main language or no?
exactly right......Evening/Morning XCOOL!!
Hey Tim! I know that I probably am. I doubt if anyone has ever clicked a + or - for me. lol
18z GFS.
108 knots.
He wasn't Personal attacking you, he was asking a simple yes/no question.
Notice that the vast majority of the observed storms recurved. However, Caroline and Eloise were both majors, and both struck a portion of the Gulf Coast. The latter was the first major hurricane to strike the Florida panhandle in many years at the time.
We are all below average...lol
Your always a trouble maker on here...:)...NEVER are you..How you doing!
Upper clouds are moving faster than the low-level ones, and we have had no idea exactly where the surface center has been all day, so we can't assume it's been moving along with the mid-level center which hasn't been vertically stacked with it. The upper clouds are causing the illusion that the system has sped up significantly, but that likely isn't the case.
~~~~~~~~~~~~~~~~~~~~
I'm out, goodnight all.
congratulations that is phenomenal.
No, he's calling ME a troll. That's the hilarious thing. But, I'm mature enough to handle it without backlash. Now we'll see if he's mature. :)
Your photos are always just gorgeous!
Kori....for the love of pete.....can't we just forget about that particular year??
Uuum, "right to left" or "east to west" is pretty easily seen, Levi. LOL. And, it's moving at a very quick clip! No doubts about it!
Good night.
92L activated during the day, disapeared in the night....
KORI....NOT TROLL!!
"DING!" That's the sound of the shine off my halo! lol
I'm hanging in there bud. I've been hurting bad, so I've just been popping on and off and reading a bit while I can.
How's by you? What's your thoughts on our storms?
LOL
I knew you'd be appalled at that. Sorry bro. ;)
I'm not necessarily insinuating anything for your area specifically. Just trying to alert people that the threat for a US landfall somewhere, isn't over.
This looks really bad! Big change for the NGP Model......geesh!
My nightmares are going to get worse.....KORI..THE MAN TRYING TO BLOW ROOF OFF MY HOUSE.....lol.....
Thats to the point, and very cool!
Probably not much effect on 92L-aside from a a southward diving split over the middle atlantic states in the jet that may reinforce the GOM/Carbbean ridge to the N of 92L.
For Igor, strong westerlies in place for a while-displaced more to the south than we have seen. Erosion of the middle atlantic ridge and a path up and out.
Would be nice if we could drag Bermuda out of the way for a while.
A 1009 mb surface low is in the ern Caribbean centered near 15n66w moving W near 15 kt (better than 17 mph).
Hmmm.
Happy WU-niversary, Beell. (Yer join date?)
Viewing: 1601 - 1651
Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 — Blog Index