Gulf of Mexico disturbance and the June hurricane outlook

By: Dr. Jeff Masters , 4:52 PM GMT on June 01, 2007

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A large area of disturbed weather continues over the Western Caribbean and Gulf of Mexico in association with a non-tropical area of low pressure. There is no circulation evident on QuikSCAT, satellite loops, or the Tampa Bay radar. Wind shear is about 20-40 knots, which is unfavorable for tropical storm formation. The shear is expected to remain high over the storm for the next few days, and I don't expect it to develop into a tropical depression. However, the storm has a lot of tropical moisture with it, and it should bring rains of 1-3 inches over western Cuba and much of Florida over the next two days, as well as the threat of 50 mph wind gusts and a few weak tornadoes. A Hurricane Hunter aircraft is scheduled to investigate the system at 2pm EDT today.


Figure 1. Total rainfall from the Key West radar.

June outlook
June is typically the quietest month of the Atlantic hurricane season. The basin averages 0.5 named storms 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 12 years since the current active hurricane period began in 1995, there have been nine June named storms. Four tropical storms have formed in the first half of June in that 12-year period, giving a historical 33% chance of a first-half-of-June named storm.


Figure 1. Tracks of all June tropical storms and hurricanes since 1851.

Sea Surface Temperatures
Sea Surface Temperatures (SSTs) are still quite cool in June, which limits the regions where tropical storm formation can occur. Typically, June storms only form over the Gulf of Mexico, Western Caribbean, and Gulf Stream waters just offshore Florida, where water temperatures are warmest (Figure 1). This year (Figure 2), SSTs are below average in the region surrounding Florida, so we should expect any storms that do form to occur in the Western Gulf of Mexico or Western Caribbean. 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. Another possibility is that the disturbed weather area in the Eastern Pacific Intertropical Convergence Zone (ITCZ) will push north into the Western Caribbean and spawn a storm there. This was the case for last year's Tropical Storm Alberto (which may have also had help from an African wave).


Figure 2. Sea Surface Temperature (SST) departure from average for May 31, 2007.

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, there is much less heat energy available this year than in 2005, which recorded the highest SSTs ever measured in the tropical Atlantic. I expect that the TCHP will continue to remain below 2005 levels this year, so we should not see as many intense hurricane as we saw in 2005.


Figure 3. Tropical Cyclone Heat Potential (TCHP) for May 31 2005 (top) and May 31 2007 (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. 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.

Wind shear over the past 11 days (Figure 4) has been very high over North America and the surrounding waters of the Gulf of Mexico and Atlantic. This is very typical for June, when the jet stream is still very active and quite far south. The jet stream will gradually weaken and retreat northwards as summer progresses, bringing lower wind shear and greater chances for tropical storm formation. Right now, the Caribbean is the only region with wind shear low enough to support tropical storm formation. The latest two-week forecast from the GFS model predicts that wind shear will remain high over the Gulf of Mexico for the first half of June, and I don't expect and tropical storms to form in the Gulf the next two weeks. Wind shear over the Caribbean is expected to fluctuate between hostile and favorable levels over the next two weeks, so it is possible we could get a tropical storm forming in the Western Caribbean.


Figure 4. Top: Average wind shear over the past 11 days. Wind shear is the difference in wind between 200 mb (roughly 40,000 foot altitude) and 850 mb (roughly 5,000 foot altitude) in meters per second (multiply by two to get the approximate wind shear in knots). In most circumstances, wind shear above 20 knots (10 m/s, the blue colors in the top image) will act to inhibit tropical storm formation. Wind shear below 12 knots (6 m/s, the orange colors) is very conducive for tropical storm formation.
Bottom: Departure of wind shear from average for the past 11 days in meters per second. Note the higher than average wind shear values over the Gulf of Mexico, a prime breeding ground for June tropical storms.

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 this year's Subtropical Storm Andrea never became a tropical storm.

Steering currents
The steering current pattern over the past few weeks has been much like 2006, 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 of hurricanes that penetrate north of the Caribbean Sea. Steering current patterns are not predictable more than about two weeks in advance, and there is no telling if we are in for a repeat of the favorable 2006 steering current pattern that recurved every storm out to sea. It is encouraging to note that in 2006 the steering current pattern locked into place in late May and stayed that way for almost the entirety of the hurricane season. I am hopeful that this pattern will occur again this year, but there is no way of telling at this point.

Summary
Recent history suggests a 33% chance of a named storm occurring in the first half of June. Given the current SST pattern and two-week wind shear forecast, the Western Caribbean is the most likely area for a storm to occur. Any storm forming in this region would likely move north or northeastward, impacting Cuba, Florida, and the Bahamas. Due to the high levels of wind shear expected over the next two weeks, I'm forecasting only a 20% chance of a named storm forming during this period.

Radio play
National Public Radio's The Story program will be airing a long interview with me today about my flight into Hurricane Hugo in 1989. The show is carried on NPR stations in MI, WI, IL, IN, IA, MN, NC, NY, VA, and WI, and airs live today at 1pm or 8pm EDT. Check http://thestory.org/Stations for local stations and times. You can also listen live on the Internet at NPR station wunc.org in North Carolina. The host, Dick Gordon, is a very gifted interviewer, and it should be an interesting program.

Last night, I was guest on the Barometer Bob Show. You can listen to a podcast of my 50-minute spiel at http://www.barometerbobshow.com/podcast/.

Jeff Masters

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844. 0741
12:23 AM GMT on June 02, 2007
we have chatroom to talk about barry too Link
843. 0741
12:05 AM GMT on June 02, 2007
show going to start now Link
842. 0741
11:47 PM GMT on June 01, 2007
June 1, 2007 at 8:00PM/ET Hurricane Hollow's Eye On The Storm
Season Opening Broadcast
http://www.wrbn.net/
841. rcw3117
10:55 PM GMT on June 01, 2007
Galveston County Tx folks I have a question.

If the mandatory evac is given do we have to go? I am getting different results to this from you stay you pay a fine, to Texas is a stay if you want State. Which is it?
840. KEEPEROFTHEGATE (Mod)
10:23 PM GMT on June 01, 2007
dirual tonight in a T.S. is always a good bet of good bursts of convection with it in centre of T.S. makes even a better shot at being a brief look at whats yet to come all signs indicate a quick intensication is likely during dirual and if it could wrap maybe we just might have something but i figure only strong T.S. status possible
Member Since: July 15, 2006 Posts: 188 Comments: 58317
839. KEEPEROFTHEGATE (Mod)
10:12 PM GMT on June 01, 2007
to all u newbies always expect the unexpected
Member Since: July 15, 2006 Posts: 188 Comments: 58317
838. weatherbrat
10:04 PM GMT on June 01, 2007
I would have never thought this system would have gotten it's act together to be a TD let alone a TS. It still doesn't look to me like there is enough evidence to support a TS. The wind shear is not favorable and the SST's are low. There doesn't seem to be the convection needed around the vortex.

It seems to me "they" are jumping the gun on this. I still believe it's just going to be a big rain maker, which is exactly what Florida/Georgia needs right now.

This is just my thoughts, please correct me where I'm wrong.
837. Rainwalker
10:01 PM GMT on June 01, 2007
I am new here, but what a start to the season
Member Since: June 1, 2007 Posts: 0 Comments: 55
836. homegirl
9:55 PM GMT on June 01, 2007
Hunters found 67kts inthe west quad!! I'm surprized to see Barry is still strengthening. I know everyone is saying this won't become a hurricane but, didn't they say it wouldn't become a TS??

NOT WISHCASTING, just wondering??

786
URNT12 KNHC 012116
VORTEX DATA MESSAGE
A. 01/21:00:20Z
B. 24 deg 13 min N
085 deg 30 min W
C. NA mb NA m
D. 50 kt
E. 290 deg 016 nm
F. 351 deg 067 kt
G. 256 deg 004 nm
H. EXTRAP 998 mb
I. 21 C/ 274 m
J. 22 C/ 466 m
K. / C/ NA
L. NA
M. NA
N. 1345 / 1
O. 0.02 / 2 nm
P. AF307 01BBA INVEST OB 14
MAX FL WIND 67 KT W QUAD 20:58:50 Z
SLP EXTRAP FROM 1500 FT.

Member Since: August 1, 2006 Posts: 45 Comments: 7425
835. StormJunkie
9:46 PM GMT on June 01, 2007
...
Member Since: August 17, 2005 Posts: 26 Comments: 16970
834. KEEPEROFTHEGATE (Mod)
9:43 PM GMT on June 01, 2007
it just goes to show we really know nothing and if ur wondering she ll track along the back of fla across the delta on wards into ga end up at the eastern great lakes nice way to start the season and theres alot more to come stay tunedwe got 5 months till end of hurricane season
Member Since: July 15, 2006 Posts: 188 Comments: 58317
833. fldoughboy
9:40 PM GMT on June 01, 2007
By this time tomorrow Barry will make landfall around Cedar Key, then eyes on Barbara I am guessing.
832. hurricane91
9:39 PM GMT on June 01, 2007
anyway for bonita beach area landfall?
830. kmanislander
9:34 PM GMT on June 01, 2007
Posted By: NorthxCakalaky at 9:32 PM GMT on June 01, 2007.

Im new on here, can everyone see my typing?


Yes we can. Interesting name
Member Since: August 19, 2006 Posts: 0 Comments: 15960
829. NorthxCakalaky
9:32 PM GMT on June 01, 2007
Im new on here, can everyone see my typing?
828. strangesights
9:31 PM GMT on June 01, 2007
Adios for today ... have fun and be prepared.
827. kmanislander
9:30 PM GMT on June 01, 2007
Posted By: MichaelSTL at 9:27 PM GMT on June 01, 2007.

A large area of disturbed weather continues over the Western Caribbean and Gulf of Mexico in association with a non-tropical area of low pressure. There is no circulation evident on QuikSCAT, satellite loops, or the Tampa Bay radar. Wind shear is about 20-40 knots, which is unfavorable for tropical storm formation. The shear is expected to remain high over the storm for the next few days, and I don't expect it to develop into a tropical depression.

He needs to update that...

Michael, this one fooled so many, including myself !
Never thought I would see a TS going this far North. Even the pros thought weak system over central or S Fla as a rain maker.

If everyone that got this wrong went looking for crow that bird would be on the endangered list LOL
Member Since: August 19, 2006 Posts: 0 Comments: 15960
826. anvilhead2
9:30 PM GMT on June 01, 2007
Srry welshcayman, it updated in the tropical page but when i reposted it it didnt waqnt to have the new image, now it did
Member Since: January 22, 2007 Posts: 14 Comments: 277
821. HurricaneRoman
9:26 PM GMT on June 01, 2007
what direction does it look Barry is follwing... i definitley think Barry will be on the extreme right side of the track ..putting it over tampa
Member Since: February 25, 2006 Posts: 2 Comments: 959
820. seminolesfan
9:26 PM GMT on June 01, 2007
Sorry Guys... I'm really not trying to feed the beast.
Member Since: June 14, 2006 Posts: 0 Comments: 2108
819. welshcayman
9:26 PM GMT on June 01, 2007
anvilhead,

why are you posting the same image over and ever again bud?
818. 1900hurricane
9:26 PM GMT on June 01, 2007
New Blog!
Member Since: August 2, 2006 Posts: 47 Comments: 11883
817. NorthxCakalaky
9:26 PM GMT on June 01, 2007
Can someone give a link of the model forcasts of Barry?
816. StoryOfTheCane
9:26 PM GMT on June 01, 2007
ive never seen a TS look like this
815. 1900hurricane
9:25 PM GMT on June 01, 2007
Small thunderstorm firing up in the center of the vortex now!
Member Since: August 2, 2006 Posts: 47 Comments: 11883
814. StoryOfTheCane
9:25 PM GMT on June 01, 2007
what the dickens? I leave for a couple hours and magically theres TS, im dumbfounded
813. seminolesfan
9:24 PM GMT on June 01, 2007
And here's 990-999 mB
Member Since: June 14, 2006 Posts: 0 Comments: 2108
812. anvilhead2
9:24 PM GMT on June 01, 2007
cxfdds
Member Since: January 22, 2007 Posts: 14 Comments: 277
811. StormJunkie
9:24 PM GMT on June 01, 2007
Only if it can develop a anticyclone BT. Wait and see I guess, but it can't get too strong. The SSTs should not support it.
Member Since: August 17, 2005 Posts: 26 Comments: 16970
810. groundman
9:23 PM GMT on June 01, 2007
Patrap are you in Biloxi?? Did I talk to you last year??
808. Bamatracker
9:21 PM GMT on June 01, 2007
wind shear is high over it...im not sure it will intensify much more. But the great thing is the rain for florida!
Member Since: May 17, 2006 Posts: 6 Comments: 1367
807. StormJunkie
9:21 PM GMT on June 01, 2007
SH looks around sees no SH

No kidding Rays huh! This will be great for y'all though. Looks like it is even going to put a good dousing over all of the fire area ☺
Member Since: August 17, 2005 Posts: 26 Comments: 16970
806. rwdobson
9:21 PM GMT on June 01, 2007
I think tomorrow the sun will rise in the west and set in the east. heck, it could happen. my idea is just as valid as anyone else's.
Member Since: June 12, 2002 Posts: 0 Comments: 1592
805. seminolesfan
9:20 PM GMT on June 01, 2007

1000 mB storm steering currents are interesting!



Mabey apoc isn't smoking something funny.LOL
Member Since: June 14, 2006 Posts: 0 Comments: 2108
804. AnnOminous
9:19 PM GMT on June 01, 2007
Oh, look, Barry has been named! o.^
802. Patrap
9:19 PM GMT on June 01, 2007
Best its not Late Aug or Early Sept on this track..Charley showed us that.
Member Since: July 3, 2005 Posts: 433 Comments: 132261
801. strangesights
9:18 PM GMT on June 01, 2007
A lot can happen with weak storms ... especially in terms of direction .. and predicting them is difficult. But past experience would seem to indicate that the water temps won't support a cat 5 at this time in the gulf. If it happens though we will search for an explanation.
800. JupiterFL
9:18 PM GMT on June 01, 2007
Actually Apocalyps2 wisdom is knowing how to spell knowing that your name should have and e in it and know should have a k in it.
Member Since: August 10, 2005 Posts: 0 Comments: 2146
799. HurricaneRoman
9:18 PM GMT on June 01, 2007
hmmm I live in sOuth florida but something is telling me it's going to hit closer toTampa .....
Member Since: February 25, 2006 Posts: 2 Comments: 959
798. Patrap
9:18 PM GMT on June 01, 2007
Its just what Fla needs relief wise.A good soaker..
Member Since: July 3, 2005 Posts: 433 Comments: 132261
797. Raysfan70
9:17 PM GMT on June 01, 2007
SH- Better watch what I wish for this season.
Member Since: July 28, 2005 Posts: 138 Comments: 57354
796. floridafisherman
9:17 PM GMT on June 01, 2007
"Thats a really dumb reason to report somone. Quit being childish about it. You need to get over the fact that other people have different Ideas from you. He's not a troll, he just has an unlikely idea and hes defending it to the best of his abilities, however limited they may seem."

its not about having differnt ideas, hellsniper. its about having differnt ideas BASED ON DATA OR INFORMATION, which apocalyspe has neither. by siding with the troll, you only empower him to troll even more.

there is nothing wrong with different ideas, as long as they are based on reality or facts. there is nothing to support it claim of it moving NW. there is EVERY indictation to support it making landfall in cental florida.
Member Since: August 28, 2005 Posts: 0 Comments: 552
795. Jedkins
9:17 PM GMT on June 01, 2007
this things just getting going, remember its had to undergo changes from a non tropical low to a full tropical cyclone which includes losing fronts, so overnight it should start getting a lot more convection going.
794. Patrap
9:16 PM GMT on June 01, 2007
The GFSx was on this 13 days ago...I post it daily.LOL
Member Since: July 3, 2005 Posts: 433 Comments: 132261

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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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