94L a threat to the Lesser Antilles; Gordon a hurricane; Helene hits Mexico

By: Dr. Jeff Masters , 3:24 PM GMT on August 18, 2012

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A large tropical wave that emerged from the coast of Africa Thursday night (Invest 94L) is located a few hundred miles southwest of the Cape Verde Islands off the coast of Africa, and is headed west at 15 - 20 mph. This storm is a threat to develop into a tropical storm that will affect the Lesser Antilles Islands as early as Wednesday. The storm is under moderate wind shear of 10 - 20 knots, and is over waters of 27.5°C. A large area of dry air lies just to the north of 94L, as seen on the latest Saharan Air Layer (SAL) analysis. This morning's 8:15 am EDT ASCAT pass caught the east side of 94L, and showed a partial surface circulation. Satellite images show just a modest amount of heavy thunderstorm activity, and I expect the earliest that 94L could develop into a tropical depression would be Sunday.


Figure 1. Morning satellite image of Invest 94L.

Forecast for 94L
The latest 8 am EDT run of the SHIPS model predicts that wind shear will be low, 5 - 10 knots, and ocean temperatures will gradually warm from 27.5°C to 28.5°C over the next four days, as 94L tracks westwards towards the Lesser Antilles. As is typical with storms making the crossing from Africa to the Antilles, dry air to the north will likely interfere with development. However, with shear expected to be low, dry air may be less of an issue for 94L than it was for Ernesto or TD 7. The storm should maintain a nearly due west track through Monday night, to a point near 50°W, about 700 miles east of the Lesser Antilles. At that point, a trough of low pressure passing to the north of 94L may be able to pull the storm more to the northwest, as suggested by the latest 06Z (2 am EDT) run of the NOGAPS model, and by three members of the GFS model ensemble forecast (Figure 2.) However, the models have been trending more towards a solution where this trough is not strong enough to influence 94L's path. This scenario will be more likely if 94L takes its time to develop, since a weaker storm will be smaller and shallower, and less likely to respond to the trough passing to the north. Our two best performing models, the GFS and ECMFW, both take 94L through the Lesser Antilles. The ECMWF, which predicts that 94L will stay weak and not develop, is faster, bringing the storm through the Lesser Antilles on Wednesday. The GFS model is slower, bringing 94L to the Lesser Antilles on Thursday as a hurricane. The models have shown poor run-to-run consistency in both the timing and the track of 94L, so it is difficult to assess which land areas might be most at risk, and when. A database of historical probabilities of storms in the same location as 94L maintained by Dr. Bob Hart of Florida State University reveals that historically, 45% of storms in this location have eventually hit land, with Canada (13% chance) and North Carolina (15% chance) the most likely targets. In their 8 am EDT Tropical Weather Outlook, NHC gave 94L a 40% chance of developing into a tropical depression by Monday morning.


Figure 2. The 00Z (8 pm EDT) run of the GFS model from August 17, 2012, was done 20 different times at low resolution using slightly different initial conditions to generate an ensemble of forecasts (pink lines.) The high-resolution operational GFS forecast is shown in white.

Gordon becomes a hurricane
Hurricane warnings are flying for the central and eastern Azores Islands as Hurricane Gordon heads eastwards at 18 mph. Gordon became the third hurricane of the 2012 Atlantic hurricane season at 5 am Saturday morning, and is sporting an impressive-looking eye on visible satellite loops. Gordon should be able to maintain hurricane status until Sunday, when wind shear will rise steeply to 30 - 40 knots, and ocean temperatures will drop to 25°C. The combined effects of high wind shear, dry air, and cooler waters will likely act to weaken Gordon to a strong tropical storm by the time it arrives in the Azores Islands Sunday night, but the storm will be strong enough to bring damaging winds and heavy rain to the Azores Islands. Gordon is not a threat to any other land areas, and the extratropical remnants of Gordon will not bring any strong winds or significant rain to Europe. The last time the Azores were affected by a tropical storm was in 2009, when Tropical Storm Grace brought 65 mph winds on October 4. No significant damage was reported. Ironically, the last hurricane to affect the Azores was the 2006 version of Hurricane Gordon, which caused minor damage in the Azores, consisting of mostly fallen trees and power outages. However, after Gordon became an extratropical low, four injuries due to falling debris from high wind were reported in Spain, and Gordon brought high winds and rain that affected practice rounds at the Ryder Cup golf tournament in Ireland. About 126,000 homes were without power after the storm in Northern Ireland and one injury was reported.


Figure 3. Morning satellite image of Hurricane Gordon.

Helene makes landfall in Mexico
Tropical Storm Helene made landfall near 10 am EDT as a tropical storm near Tampico, Mexico, with 40 mph winds. Helene's formation on August 17 ties 2012 with 1933 for the 2nd earliest appearance of the Atlantic's eighth tropical storm. Helene's rains should remain south of Texas, but moisture from Helene may feed into a stalled frontal system over the northern Gulf of Mexico and bring heavy rains to the northern Gulf Coast early next week.

I'll have a new post this afternoon, giving a quick global weather summary for July, the 4th hottest July in Earth's history.

Jeff Masters

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Quoting VAbeachhurricanes:


A propane tank will last so much longer than a charcoal grill. Especially if you buy and extra tank.
yeah..i bought the charcoal kind..have bags on hand..love the smell of a steak on charcoal lol
Member Since: August 6, 2011 Posts: 4 Comments: 42264
Quoting LargoFl:
......................GFS at 174 hours..im terrible at math..how many days is that lol
7 days 6 hours.
Member Since: Posts: Comments:
Quoting Levi32:
Good afternoon.

Blog update:

Tropical Tidbit for Saturday, August 18th, with Video
good point. you think irene and earl are analouge storms for this one? GFS every run keeps shifting west. There is no chance of this storm taking a track where it just slams into the coast kinda like a hugo or frances? i noticed you have your cone anywhere from South florida to bermuda. if this gets into the carribean, the odds of it going through the gap decrease?
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94L should be code red and Gordon should be cat 2.
Member Since: July 12, 2008 Posts: 7 Comments: 383
......................GFS at 174 hours..im terrible at math..how many days is that lol
Member Since: August 6, 2011 Posts: 4 Comments: 42264
Quoting LargoFl:
I bought last year what everyone seems to forget..a charcoal grill..if you dont have power for weeks..you will need to cook food after the storm passes..you wont need electricity or gas


A propane tank will last so much longer than a charcoal grill. Especially if you buy an extra tank.
Member Since: Posts: Comments:
Quoting Stormchaser2007:
Up to 50% already.

Not bad.

now its looking a little better
Member Since: August 6, 2011 Posts: 4 Comments: 42264
Quoting BahaHurican:
I bought two essentials last year: a battery-powered camping fan, and a solar-powered lamp. The solar-powered lamp isn't as strong as I'd like, but it works for general lighting purposes. Plus it's rechargable as long as the sun is shining, regardless of whether u have access to gas / oil or batteries.
I bought last year what everyone seems to forget..a charcoal grill..if you dont have power for weeks..you will need to cook food after the storm passes..you wont need electricity or gas
Member Since: August 6, 2011 Posts: 4 Comments: 42264
Up to 50% already.

Not bad.

Member Since: June 9, 2007 Posts: 4 Comments: 15950
Quoting Dakster:


In South Florida we call them landfills.
LOL... tallest point in Broward County... lol
Member Since: October 25, 2005 Posts: 19 Comments: 22735
367. VR46L
error
Member Since: Posts: Comments:
Up to 50%.

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT SAT AUG 18 2012

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

THE NATIONAL HURRICANE CENTER IS ISSUING ADVISORIES ON HURRICANE
GORDON...LOCATED OVER THE NORTHEASTERN ATLANTIC OCEAN ABOUT 660
MILES WEST-SOUTHWEST OF THE AZORES...AND ON TROPICAL DEPRESSION
HELENE...LOCATED INLAND JUST NORTHWEST OF TAMPICO MEXICO.

A TROPICAL WAVE LOCATED ABOUT 300 MILES WEST OF THE CAPE VERDE
ISLANDS CONTINUES TO PRODUCE DISORGANIZED SHOWER AND THUNDERSTORM
ACTIVITY. ENVIRONMENTAL CONDITIONS APPEAR CONDUCIVE FOR GRADUAL
DEVELOPMENT DURING THE NEXT FEW DAYS...AND THIS SYSTEM HAS A MEDIUM
CHANCE...50 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE
NEXT 48 HOURS AS IT MOVES WESTWARD AT ABOUT 20 MPH.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

&&
PUBLIC ADVISORIES ON TROPICAL DEPRESSION HELENE ARE ISSUED UNDER WMO
HEADER WTNT32 KNHC AND UNDER AWIPS HEADER MIATCPAT2.
FORECAST/ADVISORIES ON HELENE ARE ISSUED UNDER WMO HEADER WTNT22
KNHC AND UNDER AWIPS HEADER MIATCMAT2.

$$
FORECASTER BERG
Member Since: July 6, 2010 Posts: 113 Comments: 32855
I bought two essentials last year: a battery-powered camping fan, and a solar-powered lamp. The solar-powered lamp isn't as strong as I'd like, but it works for general lighting purposes. Plus it's rechargable as long as the sun is shining, regardless of whether u have access to gas / oil or batteries.
Member Since: October 25, 2005 Posts: 19 Comments: 22735
dont know if i caught the right pic..but the Nam has something Off the gulfcoast on tuesday.............
Member Since: August 6, 2011 Posts: 4 Comments: 42264
Quoting 954FtLCane:


Morning/afternoon Gro!!
94 still trending west, like you said. You think the trends will continue into the Gulf with the next few runs?


No, not at this time. I have connections at the NHC. I have a friend whose cousin has a fried. Now he doesn't work there, but his friend does.

I am still waiting to see how strong that trough is coming down over the US this week. Depending on how strong 94L and where it is, will be tricky. I am still leaning towards a WNW to NW jog as I wrote a couple of days ago. The models do have me a little concerned this time. I usually nail these things on day one. :)
Member Since: July 17, 2009 Posts: 71 Comments: 27210
Quoting weathermanwannabe:
Dr. Neil Frank (one of the best) always stated that he did not start to pay close attention (US wise) until a storm reached the Antilles; that was close enough in time to get a better handle on the trof and ridging pattens 2-3 days out. Also, the models were not as sophisticated then as they are now. My point is, disregard the current long-term models showing a potential US impact; we will not have any real idea until the is storm is at the Antilles and the models recalculate all of the variables at that time.

No need to worry(if you are in the US) at this juncture.

yes I have and I know you all have seen these models flip all over the place with invest in the past and this invest has been no different. The point that I am making here is that I tend to notice that these models really start to get more of a handle and agreeing with each other when they are tracking a strong Tropical Storm or Hurricane and do very bad when tracking Invests.
Member Since: Posts: Comments:
Quoting weathermanwannabe:


True. We saw the same thing recently with Ernesto when some of the earlier models took it into the Gulf then things changed as usual. Kind of hard for me to fathom folks posting tracks already from past storms suggesting that this will do the same..........Every storm is different.

On the supplies front, most folks should have the basics covered already and wait until 3 days out to wrap up the list including gas, plywood, if the 3 day track is headed your way. On my "final" list is the deviled ham spread.............Love that stuff and reminds of when I was a kid......... :)

I'm taking the posting of past tracks on this one as forecast of the the models' suggested tracks for the next 24 hrs... or the previous 24, depending on whether the GFS already used it... lol

But this does remind me to check w/ my dad about one of the plywood shutters that for some reason wasn't working. As u may be aware, plywood can cost more closer to the storm's arrival, if for no other reason than the cheaper lighter weight plywood sells out first.

Devilled ham??? uh... not so much... lol
Member Since: October 25, 2005 Posts: 19 Comments: 22735
Quoting Dakster:


Happy Birthday.

Those preparations sounds like for something other than a hurricane though...


:):))
Member Since: October 24, 2005 Posts: 0 Comments: 24906
Hurricane prep for the Gulf coast...great site here with some good tips...................Link
Member Since: August 6, 2011 Posts: 4 Comments: 42264
Quoting xtremeweathertracker:


You know i just realized the GFS, CMC, FIM, NAM, and HWRF all redevelop Helene and bring her north! Quite the consensus i would say!

You've gotta be kidding me...
Member Since: July 11, 2006 Posts: 14 Comments: 11424
I fail to see how this isn't at least 90 mph.

Member Since: July 6, 2010 Posts: 113 Comments: 32855
Quoting aquak9:
Keep Gro StAug VaBeach Dak emcf and scoos

YEEEEE -AAAHHHHHHH!!!

ya'll behave

later puppy
Member Since: July 15, 2006 Posts: 178 Comments: 56141
Ok, that's cells B2 and J9, which are a bit rotating together apparently.

B2 is rated to have half inch hail and 57dbz and only 25vil, but it's definitely rotating in some fashion, because I'm only 0.3 miles south of it and saw it with my own eyes...
Member Since: January 25, 2012 Posts: 33 Comments: 1520
Good afternoon.

Blog update:

Tropical Tidbit for Saturday, August 18th, with Video
Member Since: Posts: Comments:
Quoting pottery:

Fat Chance !
From the looks of the models, and the possibility of a very large storm, I will be busy here Preparing.

So far I've got---

Item 1-- lay in lots of non-perishables. 6 bottles should do it.
Item 2-- secure everything on 22nd Aug. i.e., nail bed to floor, tie wife to bed.

Cant think of anything else right now.
the 23rd is my Birthday, you know........

heheheheh


Happy Birthday.

Those preparations sounds like for something other than a hurricane though...
Member Since: March 10, 2006 Posts: 0 Comments: 10797
POSS T.C.F.A.
XXL/INV/94/XX
MARK
13.83N/30.31W
Member Since: July 15, 2006 Posts: 178 Comments: 56141
351. Stormchaser2007
5:32 PM GMT on August 18, 2012
Member Since: June 9, 2007 Posts: 4 Comments: 15950
350. weatherh98
5:31 PM GMT on August 18, 2012
Quoting 954FtLCane:


Morning/afternoon Gro!!
94 still trending west, like you said. You think the trends will continue into the Gulf with the next few runs?


oh god please no
Member Since: June 17, 2011 Posts: 11 Comments: 6539
349. BahaHurican
5:31 PM GMT on August 18, 2012
Quoting aquak9:
yo keep
we have no hills in Fla
deforested or otherwise
So why'd they name the place ZephyrHills, then???

Hey, Aquak...
Member Since: October 25, 2005 Posts: 19 Comments: 22735
348. Grothar
5:31 PM GMT on August 18, 2012
Quoting Chicklit:


Will be interesting to see what if any interaction occurs between ex-Helene and the front dropping into the GOM.
LinkLSU WV Loop GOM


It is expected to be a very deep trough, too. I don't know why more models have not picked up on Helene.
Member Since: July 17, 2009 Posts: 71 Comments: 27210
346. opal92nwf
5:31 PM GMT on August 18, 2012
Member Since: May 12, 2012 Posts: 14 Comments: 2890
345. hydrus
5:30 PM GMT on August 18, 2012
Quoting BahaHurican:
My bigger concern with the last 4 runs is the persistence of that high... suggesting locations north of the Antilles are less likely to "get off easy" with a storm that enters the CAR...
If that storm enters the Caribbean, there will be problems...Big ones..And I am not even considering what may be down the road..Two consecutive strikes is not unheard of.
Member Since: September 27, 2007 Posts: 1 Comments: 22687
344. xtremeweathertracker
5:30 PM GMT on August 18, 2012
Quoting Chicklit:


Will be interesting to see what if any interaction occurs between ex-Helene and the front dropping into the GOM.


You know i just realized the GFS, CMC, FIM, NAM, and HWRF all redevelop Helene and bring her north! Quite the consensus i would say!
Member Since: May 31, 2011 Posts: 57 Comments: 572
343. pottery
5:30 PM GMT on August 18, 2012
Quoting VAbeachhurricanes:


And lots of rum, when pottery sends you it.

Fat Chance !
From the looks of the models, and the possibility of a very large storm, I will be busy here Preparing.

So far I've got---

Item 1-- lay in lots of non-perishables. 6 bottles should do it.
Item 2-- secure everything on 22nd Aug. i.e., nail bed to floor, tie wife to bed.

Cant think of anything else right now.
the 23rd is my Birthday, you know........

heheheheh
Member Since: October 24, 2005 Posts: 0 Comments: 24906
342. BahaHurican
5:29 PM GMT on August 18, 2012
Quoting LargoFl:
and it offers NO protection at all
So all that work for nothing...

Member Since: October 25, 2005 Posts: 19 Comments: 22735
341. bajanmet
5:29 PM GMT on August 18, 2012
What category 94l will be on the approaching the Antilles? I know it is still days away but I will still like to know.Reading some of these comments on 94l potential wind speed, it,s a bit scary. Some say it will recurve but when it comes to weather I just don't know.Ernesto was to pass to our south,it pass to the north.
Member Since: August 8, 2012 Posts: 0 Comments: 8
340. severstorm
5:28 PM GMT on August 18, 2012
Quoting aquak9:
yo keep
we have no hills in Fla
deforested or otherwise
Nope your wrong we have plenty of hills in FL. ANT HILLS lol.
Member Since: November 25, 2007 Posts: 0 Comments: 990
339. 954FtLCane
5:28 PM GMT on August 18, 2012
Quoting Grothar:



12.3N 27.7W moving due west


Morning/afternoon Gro!!
94 still trending west, like you said. You think the trends will continue into the Gulf with the next few runs?
Member Since: September 30, 2008 Posts: 0 Comments: 108
338. weatherh98
5:28 PM GMT on August 18, 2012
Quoting Grothar:


I know, I did a number of blogs on it last night on the late shift. I think you may have been on.
\

must read them
Member Since: June 17, 2011 Posts: 11 Comments: 6539
337. LargoFl
5:28 PM GMT on August 18, 2012
you know its kinda funny, yet so dangerous with a hurricane coming in on you..and..you live in an apartment building..you cant do what we homeowners can do..you cant plywood the windows etc..most you can do is buy the batteries and food stuffs etc..kinda scary..me..i'd be on the highway headed out of its path..cant imagine being in an apt, no lights,widows blown out..just sitting there, everything in the street destroyed..maybe for weeks..geez..and this is millions of people huh
Member Since: August 6, 2011 Posts: 4 Comments: 42264
336. Chicklit
5:28 PM GMT on August 18, 2012


Will be interesting to see what if any interaction occurs between ex-Helene and the front dropping into the GOM.
Quoting Grothar:


...

Looks like they want something in the Gulf at the same time 94L is nearing the Islands

LinkLSU WV Loop GOM

Kinda looks like it's bubbling, doesn't it?
Member Since: July 11, 2006 Posts: 14 Comments: 11424
335. opal92nwf
5:27 PM GMT on August 18, 2012
Quoting hydrus:
Hurricane Donna approaching the Florida KeysThis is a radar image of Hurricane Donna over Florida Keys.

I've always thought that top picture looks so menacing and monstrous.
Member Since: May 12, 2012 Posts: 14 Comments: 2890
334. weatherh98
5:26 PM GMT on August 18, 2012
Quoting Grothar:


Wheat crackers are for the cheeses. LOL How you doing aqua?

Looks like they want something in the Gulf at the same time 94L is nearing the Islands




.....

recurve
Member Since: June 17, 2011 Posts: 11 Comments: 6539
333. tropicfreak
5:26 PM GMT on August 18, 2012
This is in Sao Miguel Island in the Azores, looking SW I believe towards Gordon.

Member Since: September 2, 2006 Posts: 110 Comments: 6878
332. hydrus
5:25 PM GMT on August 18, 2012
Quoting Grothar:


Wheat crackers are for the cheeses. LOL How you doing aqua?

Looks like they want something in the Gulf at the same time 94L is nearing the Islands

Stop saying cheese. There is no cheese..Hurricanes are not made of cheese..There were walks and pine cones, but not for lampshades...
Member Since: September 27, 2007 Posts: 1 Comments: 22687
331. Grothar
5:25 PM GMT on August 18, 2012
Quoting Hurricanes101:
anyone have the 8am coordinates and numbers on 94L

atcf site is very hard for me to access on the computer, been using my phone, but I am out of data until tomorrow morning so I cant go look lol

Thank you in advance



12.3N 27.7W moving due west
Member Since: July 17, 2009 Posts: 71 Comments: 27210
330. BahaHurican
5:25 PM GMT on August 18, 2012
Quoting weathermanwannabe:
Dr. Neil Frank (one of the best) always stated that he did not start to pay close attention (US wise) until a storm reached the Antilles; that was close enough in time to get a better handle on the trof and ridging pattens 2-3 days out. Also, the models were not as sophisticated then as they are now. My point is, disregard the current long-term models showing a potential US impact; we will not have any real idea until the is storm is at the Antilles and the models recalculate all of the variables at that time.

No need to worry(if you are in the US) at this juncture.
My bigger concern with the last 4 runs is the persistence of that high... suggesting locations north of the Antilles are less likely to "get off easy" with a storm that enters the CAR...
Member Since: October 25, 2005 Posts: 19 Comments: 22735
329. RTSplayer
5:24 PM GMT on August 18, 2012
There is some sort of vortex or funnel cloud forming over highway 22 near livingston and tangipahoa border, i saw it with my own eyes.

The cells are merging in this area...

It did not appear to be on the ground, but the wind was blowing the clouds from both directions into the same spot, and it looked like a low funnel.
Member Since: January 25, 2012 Posts: 33 Comments: 1520
328. aislinnpaps
5:24 PM GMT on August 18, 2012
My daughter-in-law has now lived long enough in Louisiana. She came over and said her dogs were out playing because it was so cool outside. It's 89 degrees with a heat index of 94. There is a 23 mph breeze. *G*
Member Since: August 22, 2009 Posts: 0 Comments: 3167
327. scooster67
5:24 PM GMT on August 18, 2012
Quoting emcf30:
East Coast DOOM Run

GFS 12Z



Sup E..........LOL at MC at the end. :)
Member Since: September 26, 2010 Posts: 0 Comments: 638

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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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