Hurricane season begins today; normal June activity expected

By: Dr. Jeff Masters , 1:38 PM GMT on June 01, 2009

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Hurricane season is upon us, and it's time to take a look at the prevailing conditions and 2-week forecast for tropical cyclone activity in the Atlantic. June is typically the quietest month of the Atlantic hurricane season. On average, we see only one named storm every two years in June. Only one major hurricane has made landfall in June--Category 4 Hurricane Audrey of 1957, which struck the Texas/Louisiana border area on June 27 of that year, killing 550. The highest number of named storms for the month is three, which occurred in 1936 and 1968. In the fourteen years since the current active hurricane period began in 1995, there have been eleven June named storms (if we include last year's Tropical Storm Arthur, which really formed on May 31). Five tropical storms have formed in the first half of June in that 14-year period, giving a historical 36% chance of a first-half-of-June named storm.


Figure 1. Tracks of all June tropical storms and hurricanes, 1851 - 2007.

Sea Surface Temperatures
Sea Surface Temperatures (SSTs) are close to average over the tropical Atlantic between Africa and Central America this year (Figure 2). These temperatures are some of the coolest we've seen since 1995, when the current active hurricane period began. This year's cool SSTs should prevent a repeat of the unforgettable Hurricane Season of 2005, which had the highest SSTs on record in the tropical Atlantic. Note also that SSTs along the Equatorial Pacific off the coast of South America are quite a bit above average, signaling the possible start of an El Niño episode. As I discussed in Friday's post, odds are increasing for a weak El Niño to form in time for hurricane season, and this should cut down on the number and intensity of Atlantic tropical storms and hurricanes this year. However, if an El Niño is developing, it shouldn't start affecting Atlantic hurricane activity until August.

Typically, June storms only form over the Gulf of Mexico, Western Caribbean, and Gulf Stream waters just offshore Florida, where water temperatures are warmest. SSTs are 26 - 28°C in these regions, which is about 0.5°C above average for this time of year. June storms typically form when a cold front moves off the U.S. coast and stalls out, with the old frontal boundary serving as a focal point for development of a tropical disturbance. African tropical waves, which serve as the instigators of about 85% of all major hurricanes, are usually too far south in June to trigger tropical storm formation. Every so often, a tropical wave coming off the coast of Africa moves far enough north to act as a seed for a June tropical storm. This was the case for Arthur of 2008 (which also had major help from the spinning remnants of the Eastern Pacific's Tropical Storm Alma). Another way to get Atlantic June storms is for a disturbed weather area in the Eastern Pacific Intertropical Convergence Zone (ITCZ) to push north into the Western Caribbean and spawn a storm there. This was the case for Tropical Storm Alberto of 2006 (which may have also had help from an African wave). SSTs are too cold in June to allow storms to develop between the coast of Africa and the Lesser Antilles Islands--there has only been once such development in the historical record--Ana of 1979, which coincidentally will be the name given to this year's first storm.


Figure 2. Sea Surface Temperature (SST) departure from average for June 1, 2009. SSTs were near average over the tropical Atlantic. Note the large region of above average SSTs along the Equatorial Pacific off the coast of South America, signaling the possible start of an El Niño episode. Image credit: NOAA/NESDIS.

Tropical Cyclone Heat Potential
It's not just the SSTs that are important for hurricanes, it's also the total amount of heat in the ocean to a depth of about 150 meters. Hurricanes stir up water from down deep due to their high winds, so a shallow layer of warm water isn't as beneficial to a hurricane as a deep one. The Tropical Cyclone Heat Potential (TCHP, Figure 3) is a measure of this total heat content. A high TCHP over 80 is very beneficial to rapid intensification. As we can see, the heat energy available in the tropical Atlantic has declined considerably since 2005, when the highest SSTs ever measured in the tropical Atlantic occurred. TCHP this year is similar to last year's levels, which were high enough to support five major hurricanes.


Figure 3. Tropical Cyclone Heat Potential (TCHP) for May 31 2005 (top), May 31 of last year (middle) and May 30 2009 (bottom). TCHP is a measure of the total heat energy available in the ocean. Record high values of TCHP were observed in 2005. TCHP this year is much lower, and similar to last year. Image credit: NOAA/AOML.

Wind shear
Wind shear is usually defined as the difference in wind between 200 mb (roughly 40,000 foot altitude) and 850 mb (roughly 5,000 foot altitude). In most circumstances, wind shear above 20 knots will act to inhibit tropical storm formation. Wind shear below 12 knots is very conducive for tropical storm formation. High wind shear acts to tear a storm apart. The jet stream's band of strong high-altitude winds is the main source of wind shear in June over the Atlantic hurricane breeding grounds, since the jet is very active and located quite far south this time of year.

The jet stream over the past few weeks has been locked into a pattern where a southern branch (the subtropical jet stream) brings high wind shear over the Caribbean, and a northern branch (the polar jet stream) brings high wind shear offshore of New England. This leaves a "hole" of low shear between the two branches off the coast of North Carolina, which is where Tropical Depression One formed. The low shear "hole" has dipped down into the northern Gulf of Mexico a few times. Disturbance 90L, which almost developed into a tropical storm before it came ashore in Mississippi/Alabama on May 23, took advantage of one of these low-shear areas.

The jet stream is forecast to maintain this two-branch pattern over the coming ten days. This means that the waters offshore of the Carolinas are the most likely place for a tropical storm to form during this period, though the northern Gulf of Mexico will at times have shear low enough to allow tropical storm formation. The latest 16-day forecast by the GFS model (Figure 4) predicts that the subtropical jet will weaken and retreat northwards by the middle of June, creating low-shear conditions over the Caribbean. This is a typical occurrence for mid-June, and we need to start watching the Western Caribbean for tropical storm formation by the middle of the month.


Figure 4. Wind shear forecast from the 00Z GMT June 1, 2009 run of the GFS model for June 1 (left panel) and June 17 (right panel). Currently, the polar jet stream is bringing high wind shear to the waters offshore New England, and the subtropical jet is bringing high wind shear to the Caribbean. This leaves the waters off the coast of North Carolina under low shear, making this area the most favored region for tropical storm formation over the next 7 - 10 days. By June 17, the subtropical jet is expected to weaken and move northwards, leaving the Caribbean under low shear, and favoring that region for tropical storm formation. Wind speeds are given in m/s; multiply by two to get a rough conversion to knots. Thus, the red regions of low shear range from 0 - 16 knots.

Dry air and African dust
It's too early to concern ourselves with dry air and dust coming off the coast of Africa, since these dust outbreaks don't make it all the way to the June tropical cyclone breeding grounds in the Western Caribbean and the Gulf of Mexico. Developing storms do have to contend with dry air from Canada moving off the U.S. coast; this was a key reason why 2007's Subtropical Storm Andrea never became a tropical storm. Dr. Amato Evan of the University of Wisconsin will issue his dust forecast for the coming hurricane season later this week, and I'll be discussing his forecast in an upcoming post.

Steering currents
The steering current pattern over the past few weeks has been typical for June, with an active jet stream bringing many troughs of low pressure off the East Coast of the U.S. These troughs are frequent enough and strong enough to recurve any tropical storms or hurricanes that might penetrate north of the Caribbean Sea. Steering current patterns are predictable only about 3-5 days in the future, although we can make very general forecasts about the pattern as much as two weeks in advance. At present, it appears that the coming two weeks will maintain the typical June pattern, bringing many troughs of low pressure off the East Coast capable of recurving any June storms that might form. There is no telling what might happen during the peak months of August, September, and October--we might be in for a repeat of the favorable 2006 steering current pattern that recurved every storm out to sea--or the unfavorable 2008 pattern, that steered Ike and Gustav into the Gulf of Mexico.

Summary
Recent history suggests a 36% chance of a named storm occurring in the first half of June. The current conditions in the atmosphere and ocean are near average, so expect about a 1/3 chance of a named storm between now and June 15. The computer models are currently not forecasting development of any tropical storms over the next seven days.

I'll have an update Tuesday afternoon, when I'll discuss the Colorado State University June Atlantic Hurricane season forecast by Dr. Phil Klotzbach and Dr. Bill Gray, which will be issued Tuesday morning.

My next analysis and 2-week outlook for hurricane season is scheduled for June 13.

Jeff Masters

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2 points for RitaEvac for punking the blog!
Member Since: August 3, 2008 Posts: 16 Comments: 5886
Actually should be called Ana, I mean look at the thing
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no comment. ;)
Member Since: August 3, 2008 Posts: 16 Comments: 5886
Quoting RitaEvac:
Flip to FOX, CNN, NBC, CBS, ABC, end up showing BREAKING NEWS....

Subtropical storm Ana has now formed in the NE Atlantic near Portuagal on the first day of 2009 hurricane season.


!!!
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Really I have been witching back and forth on CNN and The Weather Channel and there is no report on it.NHC doesn't tell it either.
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India....theres your problem right there,
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Quoting RitaEvac:
Flip to FOX, CNN, NBC, CBS, ABC, end up showing BREAKING NEWS....

Subtropical storm Ana has now formed in the NE Atlantic near Portuagal on the first day of 2009 hurricane season.


I just went to the NHC and there is no mention of this.
Member Since: April 26, 2009 Posts: 3 Comments: 3667
Well if the "INVEST" does get mentioned by the 8pm tropical weather outlook I think it'll be at a moderate chance of development. The satellite presentation is great, the shear is 30knots which is bearable for a former extra tropical storm, and lastly the winds are becoming stronger and more organized. Its going to be interesting to see if this will be labeled 92L.
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Quoting RitaEvac:
jeffs713 where you work?

Maersk Line in The Woodlands.

All the IT is handled via India, and our corporate office in Denmark.
Member Since: August 3, 2008 Posts: 16 Comments: 5886
Link

POLL: Hurricane season is here, but residents not bustling to stock up on supplies
By LESLIE WILLIAMS (Contact)
Sunday, May 31, 2009

COLLIER COUNTY — More than half of residents in hurricane-prone areas don’t feel vulnerable to storms, nor do they have a plan in place.

Those are the findings of a Mason-Dixon poll commissioned by American Initiatives and announced Thursday at the International Hurricane Research Center at Florida International University in Miami just in time for today’s start of the hurricane season. Sunday, the day before the season commenced, was a quiet one in Collier County, with no runs on emergency supplies like bottled water or batteries in local grocery and hardware stores.

However, the warnings all over television and newspapers this time of year seem to be having an effect in Southwest Florida, said David Collins, an associate at the Home Depot on Davis Boulevard.

“I’ve been here in Naples 10 years,” said Collins. “I’ve noticed that people here tend to wait until the first storm to prepare. But, there’s been more early preparation this year than a couple of years ago.”

A steady flow of battery sales has increased over the last few weeks, Collins said, and sales of permanent and portable generators have picked up recently after a steady trickle all year long.

“We get people (buying generators) all year long because people come and go all of the time,” said Collins.

The retail push to hock hurricane-season essentials was obvious at the Target store at the corner of Pine Ridge and Airport-Pulling roads Sunday, where both batteries and bottled water were on sale in special displays on the end-caps of aisles and in front of cash registers. All 12-packs of one water brand were gone from the shelf, but plenty of gallon-size containers and 15- to 24-packs remained, many on sale through this Saturday.

At Sunshine ACE Hardware in downtown Naples, water and battery-operated lanterns went on prominent display on Thursday.

Assistant Manager Mike Wood said he had helped two people Sunday who were there to buy hurricane supplies, but said he expected the big push to happen before the first storm.

“Usually when you see the biggest spike is when a storm’s coming,” he said, “when we’re in that ‘cone of probability.’”

But Wood speculated that many people have leftover supplies from last year, which spawned only one tropical storm that swept over the area and caused only minor flooding with a few exceptions.

“I still have a boatload of batteries and stuff,” he said.

The advisory released with the Mason-Dixon poll, though, says seaside residents have gotten too cavalier in their attitudes toward the hurricane threat after the last two quiet seasons.

“Nearly two years after Hurricane Katrina shocked and horrified the nation, far too many residents are still unprepared for storms,” said Bill Proenza, director of the National Hurricane Center, in a prepared release. “Last year’s below normal hurricane season may have resulted in coastal residents being lulled into a false sense of complacency.”

Gov. Charlie Crist has hit the airwaves over the last week to urge Floridians to get prepared, reminding residents that “a storm doesn’t have to be a hurricane to be destructive.”

Old Naples resident Nancy Sanders said living through Hurricane Wilma in 2005 was enough to convince her of the importance of being prepared — she said she heeded warnings and left Naples for that storm. She said she is ready for the start of this year’s season, with plenty of essentials left over from last year, like water, flashlights and battery-operated candles.

“I don’t do major hurricane preparation,” she said. “I’m a single woman. I don’t stock the cupboards, but if one’s coming, you’ll see me at Wynn’s (Market).”

Most important to her is to have a plan, she said, particularly for where she will go and how she will gather together important documents that need to come with her.

That is a major component of the preparedness push Crist and other emergency officials stress each year.

And with a few quiet seasons behind them, said Collins, residents have every reason to be on guard. Over the long-term, Florida averages a hit by one major storm every three years.

“The law of averages is going to strike,” said Collins.

- - -

Visit www.FloridaDisaster.org for help with making plans, tips, checklists for disaster supplies and pet disaster plans.

To read results of the study, go to www.hurricanesafety.org/newpoll
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Quoting jeffs713:


No worries, and my apologies for being a bit strident. It just gets irritating because my company is still stuck in the browser stone age. (they just upgraded all the computers from IE 5)


I understand where your coming from. I wouldnt be able to run half the things I run if I was using IE6. Thats gotta really be irritating...
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lol we have an invest in the cold NE Atlantic...
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jeffs713 where you work?
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Quoting WPBHurricane05:
Hurricane Freddy made landfall in South Florida today as a category 4 storm. Link



Then we have Hurricane Suiter taking the track of the 1926 Miami hurricane.
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Another view

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Hurricane Freddy made landfall in South Florida today as a category 4 storm. Link

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Hello.

Tropical or Extra-Tropical Storm on Azores islands? This tropical system has symmetric warm-core and cyclonic rotation...

http://www.ssd.noaa.gov/goes/flt/t1/loop-avn.html

http://weather.msfc.nasa.gov/cgi-bin/post-goes


Thank you and Greetings from spain.
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Quoting Stormchaser2007:


I do not use the hight and width box. I just let Firefox take care of them. Sorry about that. Ill resize them from now on.


No worries, and my apologies for being a bit strident. It just gets irritating because my company is still stuck in the browser stone age. (they just upgraded all the computers from IE 5)
Member Since: August 3, 2008 Posts: 16 Comments: 5886
I can't believe that on the first day of the hurricane season we might have a STD or TD! We might even have Ana in the next few days! Pre-92L looks really good.
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I can't change IE6, though. My IT department threw a conniption fit when I installed Firefox. And they won't install IE7 on the computers, either.
Member Since: August 3, 2008 Posts: 16 Comments: 5886
171. beell
TD1 Archive
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Quoting jeffs713:
Stormchaser2007... PLEASE add the "width" field to your huuuuge images. I use IE6 here at work, and it really makes the blog hard to read when it is 2-3 screens wide.

(to add the width field to images, after the image link, but before closing the brackets, add
width="600"
or something like that)


I do not use the hight and width box. I just let Firefox take care of them. Sorry about that. Ill resize them from now on.
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Quoting Squid28:
Okay this is a weather related subject, just not specific to forecasting. Thanks to Ike, I once again find myself in the market for window coverings for my homes windows. Since Florida has been much more of a "test zone" over the last couple of years I am hoping someone on the blog might have some experience with any of the new window protection systems.

After my near death experience last year (almost fell off a ladder on the second floor)
My critera is pretty simple, light weight, easy to install, and effective. I have looked at the polycarbonate clear panels (screw mount, no hook and loop fastener), another system that looks like tennis court wind screen and finally a coated fabric that mounts in a similar fashion (all are Miami/Dade county approved). Does anyone have any real world observations of these systems in use? I am interested in hearing good or bad comments, before I go and invest a small fortune in one of these systems. I would really like to know how they actually performed in a storm.

Roll down shutters and permanent shutters are not an option due to house design and cost constraints, besides I have picked up more than one of those systems out of my yard before.


All of the rated materials will work just fine if installed as prescribed in the NOA's. I use a combination of GE XL-10 clear panels, and .63g or.50g aluminum. All installed with the appropriate fasteners and mounting hardware in accordance to the NOA. They are all Miami Dade certified. If you get an inspection through the county and or city and pass, you can get significant discounts on your insurance for having a hardened house. Ensure you understand that all openings will need the appropriate protection, including garage doors and entry doors and skylights if you wish to qualify. I did not go with any other style coverings for the amounts of fasteners and ease of install was prohibitive. With the use of H hats above windows, you only have to actually fasten the bottoms, hence quick installation times. Good luck. Ed
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Quoting jeffs713:
Stormchaser2007... PLEASE add the "width" field to your huuuuge images. I use IE6 here at work, and it really makes the blog hard to read when it is 2-3 screens wide.

(to add the width field to images, after the image link, but before closing the brackets, add
width="600"
or something like that)


It's a problem with IE6 then, because the blogs have code built in to limit image width to the blog width, they were added I think 2 years ago.
Member Since: Posts: Comments:
Stormchaser2007... PLEASE add the "width" field to your huuuuge images. I use IE6 here at work, and it really makes the blog hard to read when it is 2-3 screens wide.

(to add the width field to images, after the image link, but before closing the brackets, add
width="600"
or something like that)
Member Since: August 3, 2008 Posts: 16 Comments: 5886
Missing French plane ran into thunderstorms.
Excerpt from article on Yahoo.com

"...The plane indicated it was still flying normally more than three hours later as it left Brazil radar contact, beyond the Fernando de Noronha archipelago, at 10:48 local time (0148 GMT, 9:48 p.m. EDT). It was flying at 35,000 feet (10,670 meters) and traveling at 522 mph (840 kph).

About a half-hour later, the plane "crossed through a thunderous zone with strong turbulence." It sent an automatic message fourteen minutes later at 0214 GMT (10:14 p.m. EDT Sunday) reporting electrical failure and a loss of cabin pressure.

Air France told Brazilian authorities the last information they heard was that automated message, reporting a technical problem before the plane reached a monitoring station near the Cape Verde islands. Brazilian, African, Spanish and French air traffic controllers tried in vain to establish contact with the plane, the company said.

Brazilian Air Force spokesman Col. Jorge Amaral said seven aircraft had been deployed to search the area far off the northeastern Brazilian coast. Brazil's Navy sent three ships.

"We want to try to reach the last point where the aircraft made contact, which is about 745 miles (1,200 kilometers) northeast of Natal," Amaral told Globo TV.

Meteorologists said tropical storms are much more violent than thunderstorms in the United States and elsewhere.

"Tropical thunderstorms ... can tower up to 50,000 feet (15,240 meters). At the altitude it was flying, it's possible that the Air France plane flew directly into the most charged part of the storm — the top," Henry Margusity, senior meteorologist for AccuWeather.com, said in a statement.
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Met Office synoptic charts seems to indicate our 'Invest' isn't going to be moving much.. a little north but still sort of in-line with Portugal.
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I can see my house from there!
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Quoting Squid28:
Okay this is a weather related subject, just not specific to forecasting. Thanks to Ike, I once again find myself in the market for window coverings for my homes windows. Since Florida has been much more of a "test zone" over the last couple of years I am hoping someone on the blog might have some experience with any of the new window protection systems.

After my near death experience last year (almost fell off a ladder on the second floor)
My critera is pretty simple, light weight, easy to install, and effective. I have looked at the polycarbonate clear panels (screw mount, no hook and loop fastener), another system that looks like tennis court wind screen and finally a coated fabric that mounts in a similar fashion. Does anyone have any real world observations of these systems in use? I am interested in hearing good or bad comments, before I go and invest a small fortune in one of these systems. I would really like to know how they actually performed in a storm.

Roll down shutters and permanent shutters are not an option due to house design and cost constraints, besides I have picked up more than one of those systems out of my yard before.


I live in Tampa and use the fabric system that you are talking about. It's lightweight and easy to install. I luckily have not had to test it yet, but I have heard they hold up just as well, if not better, than other window coverings such as plywood and metal shutters. Also, I had a friend who used them during Wilma and he had no damage at all.
Member Since: April 26, 2009 Posts: 3 Comments: 3667
Quoting beell:
Whatever happened to ole TD1?


Ended up somewhere near Greenland I suppose.
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Vince:



"Invest"

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Quoting Stormchaser2007:


Yeah it does. Im actually very surprised by this system. It looks very good and has a warm surface feature with an eye at the mid-upper levels and a displaced eye at the surface.


It looks seperated from the front, it even has an Eyewall with it. Very wierd.
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157. beell
Whatever happened to ole TD1?
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Quoting CybrTeddy:


Looks like Vince lol.


Yeah it does. Im actually very surprised by this system. It looks very good and has a warm surface feature with an eye at the mid-upper levels and a displaced eye at the surface.
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Quoting Levi32:
Yeah this is definitely a sub-tropical storm with warm-core characteristics in the lower atmosphere. It deserves to be named.

Visible Loop

Its very close, IMO. The only thing that may hold it back is a lack of verified 39+ mph winds. All quikscat shows is some borderline winds in the 30kt range. Everything higher is rain-contaminated. Also... the ULCC looks to be a bit further to the east than the LLCC.
Member Since: August 3, 2008 Posts: 16 Comments: 5886
I had a feeling this would be a crazy season- Link
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Quoting Stormchaser2007:
An INVEST has been tagged on the SSD site. Interesting.

Oh and it has an eye.



Looks like Vince lol.
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850mb vorticity is impressive:

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Quoting WPBHurricane05:
Accuweather now forecasting weather for pirates- Link


I thought it was a joke at first LOL.
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Haha. Picture this headline.

Hurricane Ana forms over the northeast Atlantic on the first day of hurricane season.
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It'll be interesting to see if the NHC recognizes the "Invest" at the 8pm TWO.
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Quoting WPBHurricane05:
Accuweather now forecasting weather for pirates- Link


BAHAHA!
I saw that and I couldn't believe my eyes...
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Quoting Vortex95:
when the NWS declares a Severe Thunderstorm watch. AccuWeather declares a disaster area.

Exactly. There is a difference between criticizing because of vagueness, and criticizing ability. What accuweather did is criticizing NWS's ability. Accuweather has a serious chip on their shoulder, always trying to "prove" the NWS wrong.
Member Since: August 3, 2008 Posts: 16 Comments: 5886
Yeah this is definitely a sub-tropical storm with warm-core characteristics in the lower atmosphere. It deserves to be named.

Visible Loop
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Accuweather now forecasting weather for pirates- Link
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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