Danny still weak

By: Dr. Jeff Masters , 7:32 PM GMT on August 28, 2009

Share this Blog
4
+

Tropical Storm Danny continues to look unhealthy, with an exposed low-level center and the main heavy thunderstorms well to the east. The center is oval instead of circular, which may portend that this center will dissipate and a new center will form under the heaviest thunderstorm activity. Danny has more of the appearance of a subtropical storm than a tropical storm on satellite imagery, and this structure will slow down any potential intensification. The amount of heavy thunderstorm activity has increased in the past few hours, though no thunderstorms have formed near the center. The latest Hurricane Hunter mission found one small spot of 45 mph surface winds between 1 - 3 pm EDT today, so Danny may barely qualify as a tropical storm. Danny's center may have begun moving to the north over the past hour, giving confidence that the storm's strongest winds and rain will stay offshore of North Carolina tonight and Saturday morning.


Figure 1. Afternoon satellite image at 3:03 pm EDT of Danny, showing the exposed swirl of clouds where Danny's center is, well displaced from the heaviest thunderstorm activity to the east. The center is oval-shaped and not circular, the sign of a weak circulation.

The forecast for Danny
With wind shear at 15 knots this afternoon, and forecast to increase to 20 knots tonight and 30 knots Saturday morning, it is unlikely Danny will be able to strengthen to more than a 50 mph tropical storm. Dry air from the upper-level low that has been keeping Danny disorganized continues to be a problem for the storm, as well. Most of the intensity forecast models continue to insist Danny will strengthen, but they have been doing a very poor job forecasting the intensity of Danny. With Danny's heavy thunderstorms all on the east side of the storm, it is unlikely that North Carolina or New England will feel tropical storm force winds from Danny when it scoots past on Saturday. Large swells from Danny creating high surf along the beaches of New England will be the primary hazard from the storm.

Massachusetts hurricane history
Two tropical storms have affected Massachusetts in the past decade, though neither of these storms brought sustained winds of tropical storm force (39 mph) to the state. Tropical Storm Beryl of 2006 just missed Cape Cod as a weak tropical storm with 45 mph winds. Beryl brought wind gusts to tropical storm force to Nantucket Island, and a 1 foot storm surge. Tropical Storm Hermine hit southeast Massachusetts on August 31, 2004, as a minimum-strength tropical storm with 40 mph winds. No land stations in Massachusetts reported tropical storm force winds during Beryl. The last time Massachusetts measured tropical storm force winds was in 1997 during that year's version of Tropical Storm Danny. Chatham recorded sustained winds of 44 mph, and Nantucket had 43 mph winds. The last time Massachusetts had hurricane force winds was in 1991 during Hurricane Bob, which hit Rhode Island as a Category 2 hurricane. Provincetown, Massachusetts measured sustained winds of 98 mph, gusting to 115 mph, and Buzzard's Bay received a 15 foot storm surge.

Invest 94L
The well-organized tropical wave (94L) mid-way between Africa and the Lesser Antilles Islands continues to be a threat to develop into a tropical depression in the next day or two. Water vapor satellite loops show that 94L has moistened the region surrounding it considerably today, and the storm is not ingesting as much dry air as this morning. However, visible satellite loops show only a small amount of heavy thunderstorm activity near the circulation center, which is broad and elongated from east to west. Shear is low, about 10 knots, and is expected to remain low, 5 - 10 knots, over the next five days. The waters are warm enough to support development, 27°C, and are expected to remain in the 27 - 28°C range over the next five days. It appears that 94L needs another 1 - 3 days to develop a well-formed circulation and become a tropical depression, given the favorable environment. NHC is giving 94L a medium (30 - 50% chance) of developing into a tropical depression by Sunday. Most of the models predict 94L will Be affected by two troughs of low pressure over the next week, which will pull the storm far enough north so that it will miss the Lesser Antilles Islands. It is then probable that 94L will be forced to the west again as the high pressure ridge steering the storm builds back in. The possible long-term threat to the U.S. East Coast is impossible to evaluate at this time.

I'm in New York City this weekend for my cousin's wedding, so will not be blogging again until Monday morning. In my absence, wundergound's severe storms expert, Dr. Rob Carver, will be posting in my blog Saturday and Sunday.

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: 62 - 12

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22Blog Index

Blog Update
Reflector site for those at work, includes Dr. Masters & Weather456, daily update.


AOI

AOI

AOI

AOI
Member Since: Posts: Comments:
61. JLPR
Quoting TropicTraveler:

For a good laugh, Look up what "El Pendejo" means in a spanish dictionary.


yep and after seeing what it meant he shouldn't use it anymore on here
thats kinda like a bad word =P
Member Since: September 4, 2007 Posts: 36 Comments: 5223
60. bwat
Little help please, I usually have an app in Google Earth to to get HH data, but for some reason Google earth keeps crashing my comp. Can anyone please post a link to a site where I can find up to date HH info?
Member Since: Posts: Comments:
Quoting Dakster:


The Hurricane Gods and "Doomcasters, WestCasters, etc.." call it "El Pendejo".

For a good laugh, Look up what "El Pendejo" means in a spanish dictionary.
Member Since: Posts: Comments:
Quoting cyclonekid:
ALL possible models i could get.




Those models are saying it will go NNW as of NOW. We'll see. Personally, I think it'll keep going west. Guess that makes me a 'westcaster'.
Member Since: Posts: Comments:
What do you think about invest 94 in the east Pacific now off SW Mexico ? Initial computer models show it might be a threat to Baja or Northwest Mexico. One model shows it going right up the Sea of Cortez. Too early to tell?
Member Since: Posts: Comments:
Kman, If the first trough misses 94L, when is the second trough due to go by?
Member Since: Posts: Comments:
Dry air is moving away from 94L
Member Since: Posts: Comments:
Quoting NEwxguy:


Just the other day a neighbor had said,New Yorkers didn't have any sense of humor,see you proved him wrong.Great sense of humor!


The Yanks will probably get rained out tonight too! :)
Member Since: Posts: Comments:
Quoting KarenRei:


We like to call that, "El Nino" ;)


The Hurricane Gods and "Doomcasters, WestCasters, etc.." call it "El Pendejo".
Member Since: Posts: Comments:
Looks like Danny is jogging North.

Very, very interesting Patrap!!!!
Member Since: Posts: Comments:
I really believe that we will have TD 13E in the pacific at 5pm. with 94E having winds of 35mph, it should be a TD ... there again i could be wrong :D
Member Since: Posts: Comments:
Nice little synopsis on 94L's westerly track, KMan. Thank you.
Member Since: Posts: Comments:
Quoting kmanislander:
Appreciate the update.

I had just posted the following when the new blog came up so will repost now rather than retype.

560. kmanislander 2:38 PM EST on August 28, 2009
Good afternoon all

I have not been on much lately but have started to pay close attention to 94L.

There are several important factors at work in respect of this feature but they are not all conducive to rapid development. On the plus side you have warm water, an anticyclone overhead and little in the way of shear ahead. On the negative side you have the fast forward speed of 23 mph, dry air close by and the inhibition caused by being tied into the ITCZ.

The net effect of all this IMO is that 94L will not likely become a TD before reacing 50W assuming it does develop. If that happens, the trough that is supposed to lift it out will probably pass it by.

There is, IMO , a greater than 50% chance of 94L entering the Caribbean, probably around 16 or 17N depending on when it develops as a cyclone and how quickly the intensity ramps up. The low center is already closing in on 40W very quickly and the models have already abandoned the abrupt right turn to the N.

I am expecting each successive model run to trend further and further W over the next 24 hours so we will see how all of this plays out.



That is a good analysis from you Kman.I am watching closely from Puerto Rico.
Member Since: Posts: Comments:
Japan needs to watch this system. It looks nice for a minimal TS.

Member Since: Posts: Comments:
Quoting NewYork4Life:


Hopefully the Red Sox can avoid a loss by being rained out this weekend!


Just the other day a neighbor had said,New Yorkers didn't have any sense of humor,see you proved him wrong.Great sense of humor!
Member Since: Posts: Comments:
Well, HH just found it to have a warm core, making it a tropical system, no matter how ugly it looks.
Member Since: Posts: Comments:
ALL possible models i could get.

Member Since: Posts: Comments:
Quoting largeeyes:
Do extra-tropical storms have warm cores?


No; they're cold-cored.
Member Since: September 7, 2007 Posts: 1 Comments: 940
Now we know Danny or 94L will do something interesting because you're gonna be gone Dr. Masters ;) haha
Member Since: Posts: Comments:
What are the dates that the first and second troughs are suppossed to go by 94L? Thanks
Member Since: Posts: Comments:
Quoting stormsurge39:
Kman, why do you believe 94L will miss the first trough? Thanks


1. Very weak therefore will follow the low level Easterly flow for the time being.

2. Fast forward speed will make it difficult to develop a closed low which in turn will prolong the move further W in the low level flow.

3. Dry surrounding air will require the system to create its own favourable environment which will take time. That means staying weak longer = further W.

4. The stronger a system is the more it feels the pull of a trough to the N. The opposite is also true. Weaker systems are not as attracted to a trough.

5. Still low in terms of latitude.

6. Still very disorganized.
Member Since: Posts: Comments:
nchurricane - Did they reopen the water after that helicopter dropped its tank in the water yesterday?
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Enjoy, Dr. M. 94L expected to become Erika

We may have two TD's in East. Pac. at 5pm. Jimena and Kevin are the next names on the list.
Member Since: Posts: Comments:
Quoting NEwxguy:
Thank you Dr. Masters,enjoy the wedding,hope everyone brings their umbrellas.Very wet Saturday for the northeast


Hopefully the Red Sox can avoid a loss by being rained out this weekend!
Member Since: Posts: Comments:


12z Latest GFS Ensemble Member Tracks
Danny
GFS Ensemble Members

Member Since: Posts: Comments:
Good afternoon...
Member Since: Posts: Comments:
well i just got back from the beach (Topsail Isalnd N.C.) and the waves are 8+ with sustained winds of 15mph and gusts to 30+
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Kman, why do you believe 94L will miss the first trough? Thanks
Member Since: Posts: Comments:
Quoting hurricanehanna:
well, he says nothing about the GOM or Carribean for 94L - so maybe the East Coast needs to get their binoculars ready and start watching...


Its still quite a ways away and if he said its impossible to predict impacts for the U.S. East Coast then it certainly is impossible to predict impacts on the Gulf Coast because the GOM is even farther away from the system then the East Coast
Member Since: Posts: Comments:
Do extra-tropical storms have warm cores?
Member Since: Posts: Comments:
Quoting IKE:


Other than Bill, everything else has had a hard time fighting the elements


We like to call that, "El Nino" ;)
Member Since: September 7, 2007 Posts: 1 Comments: 940
26. JLPR
Also 94L has very good convergence and divergence
so we should see some convection tonight
Member Since: September 4, 2007 Posts: 36 Comments: 5223




Most of the models predict 94L will Be affected by two troughs of low pressure over the next week, which will pull the storm far enough north so that it will miss the Lesser Antilles Islands. It is then probable that 94L will be forced to the west again as the high pressure ridge steering the storm builds back in. The possible long-term threat to the U.S. East Coast is impossible to evaluate at this time.
Member Since: Posts: Comments:
.SYNOPSIS...
TROPICAL STORM DANNY NORTHEAST OF THE BAHAMAS TODAY WILL TRACK
NORTHWEST TOWARD THE UNITED STATES SOUTHEAST COAST THROUGH
LATE TODAY...TURN NORTHEAST OFF CAPE HATTERAS TONIGHT...THEN MOVE
WELL NORTH OF THE AREA ON SATURDAY. A COLD FRONT WILL APPROACH THE
REGION FROM THE NORTHWEST LATE IN THE WEEKEND AND MOVE SLOWLY
THROUGH THE AREA EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1045 AM FRIDAY...NO CHANGE TO PREVIOUS FCST. STARTING TO SEE
SCT BANDS OF SHRA APPROACHING COAST IN EASTERLY FLOW BETWEEN TS
DANNY TO S AND HIGH PRES TO N. THIS ACTIVITY EXPECTED TO INCREASE
THIS AFTN AND LIKELY POPS ALONG COAST LOOK GOOD. CHC POPS INLAND FOR
DIURNAL SEA BREEZE/SOUND BREEZE ACTIVITY. TEMPS OK.
Member Since: Posts: Comments:
Here's what MET Henry Margusity blogged this morning, interesting...

Danny remains a disorganized mess this morning. The low-level center has become detached from the main area of thunderstorms, which is always a sign of non-development. What is gong to happen no is the upper-level low over Alabama will pick up Danny over New England. We should see an intensification of Danny near New England, but it will be argued whether Danny is a tropical system or an extra-tropical storm. If this or if that, it just does not matter, because the result will be the same. Wind and heavy rains will hit New England to Atlantic Canada with coastal Maine and Nova Scotia taking the brunt of the storm. Winds may gust 40-60 mph at the peak of the storm. Rainfall of 2-5 inches is possible, especially in eastern New England.
Member Since: Posts: Comments:
22. IKE
Quoting CaneWarning:
I have found this season to be rather boring.


Other than Bill, everything else has had a hard time fighting the elements, which is great news.

Looks like 94L is having some issues this afternoon.
Member Since: June 9, 2005 Posts: 23 Comments: 37860
21. JLPR
The models keep changing from north to west
and form west to north with 94L

...so confusing =S
Member Since: September 4, 2007 Posts: 36 Comments: 5223
Thank you Dr. Masters,enjoy the wedding,hope everyone brings their umbrellas.Very wet Saturday for the northeast
Member Since: Posts: Comments:
well, he says nothing about the GOM or Carribean for 94L - so maybe the East Coast needs to get their binoculars ready and start watching...
Member Since: Posts: Comments:
nice update Kman.
Member Since: Posts: Comments:
What are the chances at this point that 94L becomes a hurricane at some point in its life cycle?, because i've noticed that SHIPS has lowered its intensity predictions, and have also heard from other sources that shear in the mid-Atlantic is brutal, and could retard development
Member Since: Posts: Comments:
Member Since: Posts: Comments:
...in New York for the weekend.

I can think of some "Danny" scenario's which would make Jeff's cousin wonder...
Member Since: Posts: Comments:
Appreciate the update.

I had just posted the following when the new blog came up so will repost now rather than retype.

560. kmanislander 2:38 PM EST on August 28, 2009
Good afternoon all

I have not been on much lately but have started to pay close attention to 94L.

There are several important factors at work in respect of this feature but they are not all conducive to rapid development. On the plus side you have warm water, an anticyclone overhead and little in the way of shear ahead. On the negative side you have the fast forward speed of 23 mph, dry air close by and the inhibition caused by being tied into the ITCZ.

The net effect of all this IMO is that 94L will not likely become a TD before reacing 50W assuming it does develop. If that happens, the trough that is supposed to lift it out will probably pass it by.

There is, IMO , a greater than 50% chance of 94L entering the Caribbean, probably around 16 or 17N depending on when it develops as a cyclone and how quickly the intensity ramps up. The low center is already closing in on 40W very quickly and the models have already abandoned the abrupt right turn to the N.

I am expecting each successive model run to trend further and further W over the next 24 hours so we will see how all of this plays out.

Member Since: Posts: Comments:
Dr.Masters hope you have good weather this weekend in NY For the wedding. Dr.Carver look forward to your late night updates.
Member Since: Posts: Comments:
Quoting CaneWarning:
I have found this season to be rather boring.


How sad for you...
Member Since: Posts: Comments:

Viewing: 62 - 12

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22Blog 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.