Tropical Storm Danny likely to be named today

By: Dr. Jeff Masters , 1:25 PM GMT on August 26, 2009

Share this Blog
3
+

First-light satellite images of the tropical wave (92L) a few hundred miles northeast of the Bahama Islands show that the system has developed an organized surface circulation, and 92L will likely be named Tropical Storm Danny later today. This morning's QuikSCAT pass confirms the presence of a surface circulation, and the satellite saw top winds of 50 mph in a cluster of thunderstorms well east of the center. Wind shear has dropped to the moderate range, 10 - 15 knots. The upper-level low 92L is moving underneath has plenty of dry air in it, and the upper low is injecting this dry air into 92L's west side, keeping and heavy thunderstorm activity from developing on that side. The Hurricane Hunters are in 92L, and have found surface winds up to 57 mph so far this morning. NHC continues to give 92L a high (greater than 50% chance) of developing into a tropical depression by Thursday afternoon.


Figure 1. Water vapor satellite image from 8:15 am EDT 8/26/09 showing dry air associated with an upper-level low pressure system to the west of 92L's center of circulation. Image credit: NOAA/SSD.

The forecast for 92L
As 92L continues to plow through the upper low, the low will weaken, and wind shear is expected to decline to the low range, 5 - 10 knots, by tonight. However, the upper-level low will continue to dump dry, cold air into 92L through Thursday afternoon, slowing down development. By Thursday night, when 92L should be several hundred miles off the coast of northern Florida, the upper-level low may be weak enough and far enough away that 92L will find itself in a region with light upper level anticyclonic winds, which would favor more rapid development. Most of the intensity models, including the GFDL, HWRF, and SHIPS model, forecast that 92L will become a hurricane by Friday. However, this favorable environment will not last long, since a strong trough of low pressure will be approaching the U.S. East Coast on Friday. This trough will bring high wind shear of 20 - 30 knots by Friday night. This trough should be strong enough to turn 92L to the north. The models have come into better agreement keeping 92L offshore as it passes North Carolina, though the storm is certainly capable of giving the Outer Banks a direct hit. As 92L passes North Carolina, it should start heading north-northeast, with a second landfall likely Saturday night or Sunday morning somewhere between Massachusetts and Nova Scotia. At that time, 92L is likely to be a strong tropical storm or weak Category 1 hurricane, with winds in the 55 - 80 mph range. It currently appears that 92L will not bring tropical storm-force winds to the Bahamas or to Florida.

Elsewhere in the Atlantic
The models have been inconsistently predicting formation of several tropical waves coming off the coast of Africa over the next week, and I am going to stop mentioning these forecasts until we get two models predicting the same thing, several model runs in a row.

I'll have an update later today.

Jeff Masters

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 417 - 367

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19Blog Index

Quoting justalurker:
there are sure alot of "thinks" and "looks" right now :)


there usually are a lot of 'looks' & 'thinks'
Member Since: Posts: Comments:
Quoting 7544:
this is suppose to turn at 75 west ? thats only 3 more degerees


8
Member Since: Posts: Comments:
I know I am untrained, but I just don't see how this was named yet. The moisture is all on the west side.
Member Since: Posts: Comments:
there are sure alot of "thinks" and "looks" right now :)
Member Since: August 18, 2009 Posts: 0 Comments: 157
The NHC has made great strides in accuracy and forecasting over the last several years. As a matter of fact, look at Hurricane Bill, they were very accurate with the forecast track, although they were continually changing the forecasted intensity. There are over 20 other major hurricane forecasters (per the NHC), that offer their expert opinions/forecasts for all to enjoy! I think the Wunderblogs are an excellent avenue for people to share info on current storms and all confess we are "weather fanatics"!
Member Since: Posts: Comments:

Is that lovely swirl that you can see on the visible the upper level low pulling away? Is the center there or is it down towards the bottom where the convection is? I'm sure Danny's "blobby nature" will improve by this afternoon.

http://www.goes.noaa.gov/HURRLOOPS/huvsloop.html
Member Since: September 4, 2005 Posts: 0 Comments: 149
408. 7544
Quoting eddye:
it looks like dannycould head to south east fl and the bahamas


the naked swirl might make it there the rest idk
Member Since: Posts: Comments:
406. eddye
it looks like dannycould head to south east fl and the bahamas
Member Since: Posts: Comments:
I'm more of a lurker than anything in here. I'm in Vancouver , Canada with very little/no effect from these storms. Though I do have some interests in Hawaii and I am watching those storms closely. I am trying to learn. Obviously there are many books I can read. I find TampaSpin's and StormW's site very informative. But of all the graphs and maps posted which ones do you find the most helpful to figuring out if a storm will develop and then the steering path it may take when it develops. And with so many models are there some that you find are more accurate in their tracks than others?
Member Since: August 23, 2009 Posts: 0 Comments: 16
Here in VA Beach watching intently. Our last TS Isabelle caused a lot of damage around here. Danny seems to be close to the same though Isabelle was a stronger storm initially. We can't evacuate from here as the traffic patterns make almost impossible with less than a 3 day warning. Checking out the generator now.
Member Since: Posts: Comments:
I think danny (the nekkid swirl) will be dancing with the chippendale's on south beach at this rate....
Member Since: Posts: Comments:
Quoting stormsurge39:
Could somebody please tell me what that blow up is in the NE GOM?

I think it is the tail end of the front. I saw it yesterday on satellite, but couldn't ask about it in the blog. Pat?
Member Since: Posts: Comments:
401. 7544
this is suppose to turn at 75 west ? thats only 3 more degerees
Member Since: Posts: Comments:
Hey All-

What's going in the GOM???? New wave off Africa looks impressive!!!!
Member Since: Posts: Comments:
Thanks WXLogic, The reason i asked is, because Tampa spin on Monday showed a NAM model develpoing a system within 48 to 60 hours from then.
Member Since: Posts: Comments:
Quoting IKE:


I agree.

90L that hit the Florida panhandle and SW Alabama back the first of the season looks better than Danny...right now.


too bad looks dont matter
Member Since: Posts: Comments:


storms trying to build around to the north of the COC.
Member Since: Posts: Comments:
395. IKE
Quoting btwntx08:

that possible invest looks better than danny


I agree.

90L that hit the Florida panhandle and SW Alabama back the first of the season looks better than Danny...right now.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
The Africa Wave Train...

Member Since: August 14, 2008 Posts: 0 Comments: 137
That was a little surprise, especially forecasting Cat 1. We knew it had the winds so I guess when ready for numbering go directly TS.
Member Since: Posts: Comments:


LLC looks like just north of due west to me.
Member Since: Posts: Comments:
"Whew" hope this forecast is the real deal.

TROPICAL STORM DANNY FORMS

WEDNESDAY 11:15am - ED PIOTROWSKI - 15weather@wpde.com
INTENSITY
Visible satellite images this morning show the tropical system north of Hispaniola appears to have a clearly defined circulation. Hurricane Hunters have determined we indeed have a tropical storm. The one entity that seems to be hampering development is an upper level low pressure system that's sitting right on top of it. Upper level lows are loaded with cold air and that is never a good thing for a tropical system whose very survival relies on warm, moist air. Until that upper low weakens late Wednesday or Thursday, any development will be slow to occur. When the upper low gets out of the way, light wind shear and sufficiently warm waters could allow this system to develop more quickly. In fact, some of the intensity forecast models suggest "Danny" could become a hurricane. At this time there are no watches or warnings for the South Carolina coast.

TRACK
Whether the storm develops or not, it is becoming very clear that another strong trough of low pressure moving in at the end of the week will ultimately turn the system north then northeast before it ever reaches the South Carolina coast. Now that the forecast models have latched on to a more clearly defined center, they are in very good agreement on keeping this system east of Cape Hatteras. Even the ECMWF, the most accurate model last year and so far this year, takes it over the Outer Banks.

SOUTH CAROLINA IMPACTS
Outside of increasing swells and a higher rip current risk Friday and Saturday, there will be NO impacts here. We'll have a better chance of showers and storms Friday and Saturday, but that's because of the cold front moving in, not a tropical system. If you have plans to come to the beach this weekend, don't cancel. Based on everything I've seen, I wouldn't!
Member Since: Posts: Comments:
Quoting stormsurge39:
Could somebody please tell me what that blow up is in the NE GOM?


It's convection being enhanced by the Cut Off low in the C Gulf Coast region. No low pressure associated with it just a cluster of storms.
Member Since: August 14, 2008 Posts: 4 Comments: 4972
Quoting bingcrosby:
Right now I'm leaning towards a CMC/NAM blend. GFS is out to lunch on the 12z run!

Cmc is too strong...it has been unreliable this year.
Member Since: Posts: Comments:
Could somebody please tell me what that blow up is in the NE GOM?
Member Since: Posts: Comments:
Ok. Must pry myself away from here for now. Gotta service call and it's time to make some bread. It's probably just a blown fuse...can you say electrician?
Member Since: October 18, 2005 Posts: 4 Comments: 3052
384. IKE
Possible invest off Africa....

Member Since: June 9, 2005 Posts: 23 Comments: 37858
Right now I'm leaning towards a CMC/NAM blend. GFS is out to lunch on the 12z run!
Member Since: August 14, 2008 Posts: 0 Comments: 137
Member Since: September 14, 2007 Posts: 3 Comments: 3963
Quoting VAbeachhurricanes:




Not looking good for me here on in eastern,nc
Member Since: Posts: Comments:


Member Since: Posts: Comments:
Quoting Prgal:
I dont mean to offend anyone, but why do some people ask questions that have obvious answers? Is it going to hit Florida? Is it going to affect Texas? Its like me asking "Do you think it will affect us in PR?...its close to us". Geez...look at the forcast maps! Ok, back to lurking.


Well said!
Member Since: Posts: Comments:
GFS says that by Friday Danny still won't have a western component....

Member Since: August 14, 2008 Posts: 0 Comments: 137
Quoting hurricanejunky:


Me either...it's annoying to be arbitrarily banned for no reason.

Good to know I wasn't the only one. I asked for a reason why and never got one. I've seen a lot worse happen and no bans...and during storms.
Member Since: Posts: Comments:
Quoting BurnedAfterPosting:


Very well said, thank you for seeing my point


You're welcome. Us pods try to help out the real people from time to time...
Member Since: October 18, 2005 Posts: 4 Comments: 3052
I'm agreeing more with GFS... it seems to represent its current state and future behavior better given shear it will be encountering in 48hrs or so...
Member Since: August 14, 2008 Posts: 4 Comments: 4972
Quoting hurricanejunky:


Me either...it's annoying to be arbitrarily banned for no reason.

i dont what you are talking about..floodman explained to me why i was banned..and it was exactly what i did..back to lurking before i get in trouble..
Member Since: August 18, 2009 Posts: 0 Comments: 157
373. IKE
Quoting 954FtLCane:
all i see is a nekkid swirl at 25/71...


Same here. I looked at the CIMSS shear map and it shows low shear where Danny-boy is at. I do see some convection trying to get wrapped around the outside of the western half of the circulation.

NHC and Dr. Masters think conditions will become more favorable down the road.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting bingcrosby:
Danny looks horrible on the GFS through 48 hours....


link?
Member Since: Posts: Comments:
Quoting NRAamy:
Sooo....give me your thoughts on Danny

Danny needs to lay off the steroids....sorry, you were talking about Danny Boneduci, right?

Um, yea- no. Danny in the Atlantic. hee hee
Member Since: Posts: Comments:
370. 789
well done not much bs
Member Since: Posts: Comments:
Quoting TampaFLUSA:

I was banned and I didn't post any pic, just responded lol...I think justalurker flagged everyone....


Me either...it's annoying to be arbitrarily banned for no reason.
Member Since: Posts: Comments:
Quoting DaytonaBeachWatcher:

Lol the only thing u didnt say that i would expect is "i'm out" see ya soon, jp. lol


It is very very sad that you assume I am someone else and your assumption might get me banned

You can believe what you want though, I really could care less
Member Since: Posts: Comments:
Danny looks horrible on the GFS through 48 hours....
Member Since: August 14, 2008 Posts: 0 Comments: 137

Viewing: 417 - 367

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

Local Weather

Mostly Cloudy
63 °F
Mostly Cloudy