ATL: DORIAN - Post-Tropical - Discussion

[Gustywind]

Storm Dorian to Approach Leewards This Weekend
by Alex Sosnowski, Expert Senior Meteorologist
July 25, 2013; 5:11 AM
http://www.accuweather.com/en/weather-n ... e/15685176

A tropical system that moved off the coast of Africa last weekend has become the fourth tropical storm of the 2013 Atlantic season Wednesday.

A slightly north of west path is forecast with Dorian through this weekend into early next week, most likely taking the feature close to or just north of the Lesser Antilles.

Conditions in the Leeward Islands this weekend will depend upon the exact path and strength of the tropical storm. There is a possibility of gusty, drenching squalls developing in the area Sunday into Monday, if the system were to track close by.

According to AccuWeather.com Hurricane Expert Dan Kottlowski, "The vast area of dry air surrounding the system to start the week has diminished and would tend to favor strengthening during the middle of the week."

At 8:00 a.m. EDT, Wednesday, the system may have already been a tropical storm. Enhanced satellite images during the morning hours indicated a concentrated area of thunderstorms with some rotation.

At 10:30 a.m. EDT Wednesday, winds were officially estimated to be sustained at 50 mph near the center and the system was named Dorian.

At 5:00 a.m. EDT Thursday, sustained winds were estimated to be 60 mph.

Official investigation by the National Hurricane Center will continue. Sustained winds must reach 74 mph for the system to be classified as a hurricane.

"Later this week, Dorian will move into a zone of cooler waters, which may cause the system to plateau or even weaken," Kottlowski stated.

The path of Dorian next week will depend on the strength of the tropical system itself and other weather systems surrounding it. Currently, Dorian was moving swiftly along to the west-northwest at around 20 mph.

"It is too early to say with confidence for next week where Dorian will track and what the strength will be," Kottlowski added.

It could be scooped up by the back side of high pressure near Bermuda over the Atlantic Ocean. In this scenario, the feature could then travel along the East Coast of the United States.

Another scenario allows Dorian to miss the "right turn lane" and continue west-northwestward brushing northern shores of Puerto Rico, Hispaniola and Cuba.

[TreasureIslandFLGal]

Of course the timing couldn't be better... my sister and her family finally committed to visiting us from the 3rd thru the 11th. That alone makes me think that this will end up coming our way enough to make it a rain out and us not be able to take the kids to Busch Gardens on the 8th or 9th.

They will probably be scared off now and not want to visit if they see a storm heading towards Florida.

-not that that is a done deal by any means.... but since it is a possibility per models right now, and the newscasters are already saying that it could affect Florida down the road... I'm sure she'll be calling me all worried this weekend.

I like tracking the storms, but I hope this doesn't ruin their trip. I haven't seen "my babies" for over a year.

[Gustywind]

Tropical Storm Dorian in the Eastern Atlantic
Published: Jul 25, 2013, 7:11 AM EDT weather.com

http://www.weather.com/news/weather-hur ... c-20130723

Tropical Storm Dorian strengthened quickly Wednesday, after first designated as "Tropical Depression Four" just before 5 a.m. EDT over the far eastern Atlantic Ocean, southwest of the Cape Verde Islands.

Dorian will continue tracking west-northwest over the next several days on the south side of the Bermuda-Azores high, and will remain over open waters through much of the upcoming weekend.

It may approach the longitude of the Leeward Islands, the Virgin Islands and Puerto Rico, Sunday night into Monday. While it appears more likely Dorian's center will track north of those locations, keep in mind average National Hurricane Center forecast track errors (2010-2012) in the four-to-five day period range from 180-235 statute miles. Some fringe effects are possible in these areas even if the center tracks to the north.

Additionally, there are some potential hostile factors for further strengthening.

First, dry, stable air is both immediately ahead of and blasting behind Dorian, according to an analysis by UW-CIMSS and NOAA/HRD.

Then, west to southwest wind shear, particularly strong over the eastern Caribbean Sea and Lesser Antilles, but also extending to the east, may remain in place to shear Dorian.

Average National Hurricane Center forecast intensity errors (2010-2012) in the four-to-five day range are roughly 15 knots. In this case, this could be the difference between Dorian shearing out to a tropical depression or weak tropical storm, or becoming a hurricane.

Interests in the Leeward Islands, Puerto Rico, the Virgin Islands, Hispanola, the Turks and Caicos and southeast Bahamas should monitor the progress of this system.

It is far too soon to either rule out or speculate about a U.S. threat.

[northjaxpro]

If Dorian makes it to 20N 70 W before beginning to curve, the probability increases signicantly that the SE US coastline will get impacted. As someone stated earlier, a weaker Dorian will stay a bit farther south and west. A stronger Dorian will morelikely stay more north and east.

I think if Dorian is a stronger cyclone, I have a feeling he will begin to feel the effects of the trough which is progged to be from the Great Lakes to the mid Atlantic early next week, and would make the turn aroung 65 -70 degrees Longitude, or just east of the Bahamas. But, will the trough be strong enough to pull Dorian up and away and give everyone along the U.S. East coast a big sigh of relief? Or will the trough lift out and the ridge re-establishes itself firmly making Florida a bullseye? Interesting days ahead. _________________________ The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of this poster. Please refer to the NHC and NWS products.

[jlauderdal]

06z GFS...Landfall SFL
http://www.tropicaltidbits.com/analysis ... opics.html

how many times have we been hit on model runs, wilma 2005 last time we were actually hit and that was from the west of all places..one of these days though.. BAM POW SMACKED...

I think it's a conspiracy to increase the browsing numbers on this board, now all those GOMER people will start hanging around...

rock will be on full alert if we can get this thing past 80w on a run today...


Sent from my MB886 using Tapatalk 2

[TreasureIslandFLGal]

Regardless of whether Dorian makes it all the way across or not, this does seem a bit early by a couple of weeks to see a system track the whole way across. July doesn't usually see the cape verde systems do that. I wonder if teh ridge is somewhat "set" now in its general positioning, or whether it will ooze further east or west for the real meat of the season. Anything but further east, and the CONUS will be dealing with a rought hurricane season this year.

[TreasureIslandFLGal]

If Dorian makes it to 20N 70 W before beginning to curve, the probability increases signicantly that the SE US coastline will get impacted. As someone stated earlier, a weaker Dorian will stay a bit farther south and west. A stronger Dorian will morelikely stay more north and east.

I think if Dorian is a stronger cyclone, I have a feeling he will begin to feel the effects of the trough which is progged to be from the Great Lakes to the mid Atlantic early next week, and would make the turn aroung 65 -70 degrees Longitude, or just east of the Bahamas. But, will the trough be strong enough to pull Dorian up and away and give everyone along the U.S. East coast a big sigh of relief? Or will the trough lift out and the ridge re-establishes itself firmly making Florida a bullseye? Interesting days ahead.

_________________________

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of this poster. Please refer to the NHC and NWS products.

Agree with your analysis Jax. I'm hoping that the shear and SSTs ahead of Dorian will NOT take their tole on the storm so that it does continue to strengthen and the likelihood of a recurve increases. -or at least a temporary recurve enough to pull Florida out of the crosshairs if it does get pushed back westward again with an increasing ridge.

If the storm does get affected by those impediments though, and stays weaker, then the chances of it continuing on a more westward path (weaker systems steered by lower level flow) towards Florida and/or the GOM increase. This one at this point doesn't look like it would be completely torn apart by going over hispanola either--appears like it would be tracking north of the "hurricane killer" in either case (at this point).

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[blp]

00z Euro is the further west and weakens it considerably in the bahamas.

http://moe.met.fsu.edu/cgi-bin/ecmwf-opertc2.cgi?time=2013072400&field=850mb+Vorticity&hour=Animation

[blp]

Well the FIM likes it. One of the few models to show that intensity in the Bahamas, most models our now weakening in Bahamas. Don't know the reliability on this model.

168hr


234hr

[cycloneye]

SSD Floater finally has changed to the normal updates.

http://www.ssd.noaa.gov/PS/TROP/floater ... oater.html

[KWT]

I think the model consensus at the very least is for Dorian to be a threat to the Bahamas, with perhaps a curve to the north starting to emerge...but its still much too early to say for sure.

[northjaxpro]

FIM showing the curve happening right at the approach of the East Central Florida coast with landfall at around Daytona Beach at 234 hours.

These model runs are certainly interesting to follow that's for sure. But, this is certainly a possibility at this juncture.

[TreasureIslandFLGal]

That model sure puts Jax in the crosshairs....actually....it scrapes the whole east coast of Florida. That would be a very bad scenario were that to pan out!

[cycloneye]

Joe Bastardi ‏@BigJoeBastardi
Unless track shift south, impact to Caribbean islands minimal.. a surfers storm, nothing else. Bahama headache tho

[northjaxpro]

That model sure puts Jax in the crosshairs....actually....it scrapes the whole east coast of Florida. That would be a very bad scenario were that to pan out!

Yeah, that would not be good at all TreasureIslandGirl. You are right, that would put my area right in the crosshairs. It is just one model run, but no doubt that run got my attention. These model runs are going to change so much in these next several days it will make your head spin lol...

[KWT]

AFTER THAT...DORIAN SHOULD
APPROACH A WEAKNESS IN THE RIDGE...WHICH SHOULD LEAD TO A
WEST-NORTHWESTWARD MOTION AT A DECREASED FORWARD SPEED. THE
GUIDANCE ENVELOPE HAS SHIFTED A BIT TO THE NORTH SINCE THE PREVIOUS
ADVISORY. BASED ON THIS...THE NEW FORECAST TRACK WILL BE NUDGED A
LITTLE TO THE NORTH...

How do you spell fish (lol) - it's already at 16N so just a guess based on past storms the chance of a recurve is pretty high - the trough over the south is forecast to remain the next few days so that'll only increase the chance of a recurving system, Bermuda high or no...

Personal Forecast Disclaimer:
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

Its going to be a close call I think, we are near the start of August, had this been later in the season I think you could be more confident, but at this time of year typically those mid Atlantic highs will be close to being their strongest.

Right now too many models are shunting this towards the Bahamas to feel any sort of comfort based on the fact its at 16N. I think it WILL go further north than expected but that is no safety net for Florida or the East Coast at this time of year...as systems have proven before.

[Jimsot]

Joe Bastardi ‏@BigJoeBastardi
Unless track shift south, impact to Caribbean islands minimal.. a surfers storm, nothing else. Bahama headache tho

I think that large area of squally weather to the south that is part of Dorian's circulation will probably bring Anguilla some needed rain and some gusty winds.

[KWT]

Yeah there will be plenty of changes to the models over the next few days as they come to grips with what shear maybe like and the exact timings and strengths of the highs/lows.

There does appear to be a higher shear zone around 60-70W that is being forecasted, but these things are well known to change rather quickly.

[gatorcane]

Latest guidance, more consensus and a northern shift which the NHC does mention in the 5AM EST discussion:

[KWT]

I think as the system gets further north that convective supply may start to cut off and dwindle somewhat, thats certainly what most models are suggesting will happen.