93L near tropical depression strength

By: Dr. Jeff Masters , 2:31 PM GMT on June 25, 2010

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The first tropical depression of the 2010 Atlantic hurricane season appears imminent in the Western Caribbean, as the areal coverage and intensity of heavy thunderstorm activity associated with the tropical wave (Invest 93L) continue to increase. The storm has developed a surface circulation near 16.5N, 82.5W at 8am EDT, about 100 miles northeast of the Nicaragua/Honduras border. This is far enough from land that development will be slowed only slightly. Satellite loops show a poorly organized system, with only a modest amount of heavy thunderstorm activity near the center. However, the developing storm is affecting the weather across the entire Western Caribbean, and bands of heavy thunderstorms are quickly building over a large region. Pressures at ground stations and buoys all across the Western Caribbean have been falling significantly over the past day (Figure 2.) Water vapor satellite loops show that moist air surrounds 93L, and there is not much dry air to slow down development. There is an upper-level high pressure system a few hundred miles west of 93L, and the clockwise flow air around this high is bringing upper-level winds out of the northwest of about 10 - 15 knots over 93L, contributing to the 10 - 15 knots of wind shear observed in this morning's wind shear analysis from the University of Wisconsin's CIMSS group. Sea Surface Temperatures are very warm, 29 - 30°C. The Madden-Julian oscillation (MJO) currently favors upward motion over the Caribbean, which will act to increase the chances of tropical storm formation this week. The main negative for 93L is a combination of lack of spin and wind shear. Last night's pass of the ASCAT satellite showed a broad, elongated circulation, which will need to tighten up in order for 93L to become a tropical depression. The Hurricane Hunters are scheduled to fly into 93L at 2pm EDT this afternoon to see if a tropical depression has formed.


Figure 1. Morning visible satellite image of the central Caribbean disturbance 93L.


Figure 2. Combined plot of wind speed, wind gusts, and pressure at buoy 42057 in the Western Caribbean. Pressure (green line) has fallen significantly over the past two days, and winds are beginning to increase.

Forecast for 93L
The greatest risk from 93L to the Western Caribbean will be heavy rainfall, and the nation most at risk is Honduras. The counter-clockwise flow of air around 93L will bring bands of rain capable of bringing 4 - 8 inches of rain to northern Honduras over the next two days. Heavy rains of 3 - 6 inches can also be expected in northeast Nicaragua, Cuba, Belize, the Cayman Islands, and Mexico's Yucatan Peninsula. The storm is moving west-northwest at about 10 mph, and this motion is expected to gradually slow over the next five days to about 6 mph. I expect that by tomorrow, 93L should be closer to being directly underneath the upper level high pressure system to its west, which would act to lower wind shear and provide more favorable upper-level outflow. NHC is giving 93L a 70% chance of developing into a tropical depression by Sunday morning, which is a reasonable forecast. The storm will probably be a tropical depression or tropical storm with 40 mph winds when it moves over Mexico's Yucatan Peninsula on Sunday. The storm will probably spend a day or so over the Yucatan, resulting in significant weakening. Once 93L emerges over the Gulf of Mexico, it will take the storm 24+ hours to recover its strength.

A trough of low pressure is expected to swing down over the Eastern U.S. on Monday. If this trough is strong enough and 93L develops significantly, the storm could get pulled northwards and make landfall along the northern Gulf of Mexico coast. This is the solution of the GFDL and HWRF models. If 93L stays weak and/or the trough is not so strong, the storm would get pushed west-northwestwards across Mexico's Bay of Campeche and make landfall along Mexican coast south of Texas, or in Texas. This is the solution of the NOGAPS, ECMWF, and Canadian models. A likely landfall location is difficult to speculate on at this point, and the storm could hit virtually anywhere along the Gulf of Mexico coast given the current uncertainty in its development. The amount of wind shear in the Gulf of Mexico next week is also highly uncertain. There is currently a band of high shear near 30 knots over the Gulf. The GFS model predicts that this band of high shear will lift northwards, keeping low wind shear over the Gulf next week. However, the ECMWF model keeps high shear entrenched over the Gulf of Mexico, which would make it unlikely 93L could intensify into a hurricane. In summary, I give 93L a 60% chance of eventually becoming Tropical Storm Alex, and 10% chance of eventually becoming a hurricane.

Elsewhere in the tropics
A tropical wave a few hundred miles northeast of the northernmost Lesser Antilles Islands is producing a modest amount of heavy thunderstorm activity. This system was designated Invest 94 by NHC this morning, and is passing beneath a trough of low pressure that is generating 30 - 40 knots of wind shear. However, by Sunday, the storm will be in a region of much lower wind shear, and NHC is giving the storm a 10% chance of developing into a tropical depression by Sunday morning. We do have one model, the GFS, which develops the system early next week. The GFS model takes the storm to the northwest and then north, predicting it will be very close to Bermuda on Tuesday.


Figure 3. Hurricane Celia as a Category 4 storm at 20:55 UTC Thursday, June 24, 2010, as captured by NASA's MODIS instrument.

Impressive Hurricane Celia hits Category 5
The first Category 5 hurricane in the Northern Hemisphere this year is Hurricane Celia in the Eastern Pacific. Celia's 160 mph winds make it tied with Australia's Tropical Cyclone Ului as the strongest tropical cyclone in the world so far in 2010. Celia has likely peaked in intensity, and is not expected to threaten any land areas.

Wind and ocean current forecast for the BP oil disaster
East to southeast winds of 5 - 15 knots will blow in the northern Gulf of Mexico today through Tuesday, according to the latest marine forecast from NOAA. The resulting weak ocean currents should push the oil to the west and northwest onto portions of the Louisiana and Alabama coasts, according to the latest trajectory forecasts from NOAA and the State of Louisiana. I would expect Mississippi to have its most serious threat of oil yet early next week as these winds continue. The longer range outlook is uncertain, and will depend upon what 93L does.

Resources for the BP oil disaster
Map of oil spill location from the NOAA Satellite Services Division
My post, What a hurricane would do the Deepwater Horizon oil spill
My post on the Southwest Florida "Forbidden Zone" where surface oil will rarely go
My post on what oil might do to a hurricane
NOAA's interactive mapping tool to overlay wind and ocean current forecasts, oil locations, etc.
Gulf Oil Blog from the UGA Department of Marine Sciences
Oil Spill Academic Task Force
University of South Florida Ocean Circulation Group oil spill forecasts
ROFFS Deepwater Horizon page
Synthetic Aperture Radar (SAR) imagery from the University of Miami

Jeff Masters

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The center of TD1 seems a bit south of where everyone thought it was.

Member Since: Posts: Comments:
2528. Michfan
Quoting ezcColony:
That storm system is truly remarkable in size for June. Absolutely amazingly BIG!


Its size is going to have a two fold effect on it. One its going to be able to pull moisture in from just about anywhere, but on the flip side its large size is a hindrance to to its intensification at the moment. Its taking much more energy for it to wind up as opposed to what you would see with a tighter small system.
Member Since: Posts: Comments:
Quoting truecajun:
am i banned? my posts won't show up


Lol nope you're good.
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Quoting ShenValleyFlyFish:


Does SSI have to put on a shirt? I lost track.


I can't remember what the bet was now! LOL
Member Since: Posts: Comments:
am i banned? my posts won't show up
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2524. Patrap
I guess BP can turn the Flare off..pack their,,er "stuff" and Bug out.

WUnderful...
Member Since: July 3, 2005 Posts: 415 Comments: 125752
Of course they did the whole breaking news alert and told us to stay tuned to the weather report to see what TD#1 means for our weather. LOL

I can guarantee you about 20 elderly folks just wet their pants with that.
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<
Member Since: August 19, 2006 Posts: 0 Comments: 15671
Quoting CaneWarning:
IKE can't post 0-0-0 now.


Does SSI have to put on a shirt? I lost track.
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2520. gator23
Quoting RecordSeason:
TD1 is conservative, IMO.

It'll be a TS by the time TWC even mentions TD status...

knowing TWC it will be a CAT 5 before they mention TD status
Member Since: Posts: Comments:
Quoting CosmicEvents:
I said 4 days ago that we'd have a TD at 6PM EST on Friday.


Lucky guess.........
Member Since: August 8, 2006 Posts: 0 Comments: 8311
2518. cg2916
Finally, after all the waiting, the season is here!!!
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2517. Levi32
Down to 1004.3mb again and they're still measuring brisk southerly winds which means the central pressure continues to fall with every pass. They are honing in on the center.

000
URNT15 KNHC 252135
AF302 01AAA INVEST HDOB 42 20100625
212530 1600N 08305W 9785 00234 0050 +242 +180 235018 018 007 000 00
212600 1601N 08306W 9778 00239 0049 +244 +180 240016 017 003 001 03
212630 1602N 08307W 9780 00237 0047 +242 +180 238017 017 002 001 03
212700 1603N 08307W 9781 00235 0046 +243 +180 241018 018 000 000 00
212730 1605N 08308W 9781 00235 0046 +241 +180 244017 017 001 000 00
212800 1606N 08309W 9778 00237 0047 +240 +180 239016 017 000 000 03
212830 1607N 08310W 9785 00231 0046 +242 +180 236017 017 000 000 03
212900 1609N 08311W 9778 00237 0046 +239 +180 235018 019 000 000 00
212930 1610N 08312W 9782 00233 0046 +239 +180 234019 020 005 000 00
213000 1611N 08313W 9781 00233 0045 +237 +180 233018 019 007 000 00
213030 1612N 08314W 9782 00231 0045 +236 +180 230019 019 010 000 00
213100 1614N 08315W 9779 00235 0045 +242 +180 227018 018 013 001 00
213130 1615N 08316W 9782 00233 0046 +234 +180 228018 019 020 000 00
213200 1616N 08317W 9781 00233 0045 +238 +180 229021 022 018 000 00
213230 1618N 08318W 9779 00234 0045 +235 +180 228020 021 021 003 00
213300 1619N 08318W 9778 00234 0045 +225 +180 219021 022 024 003 00
213330 1620N 08319W 9783 00229 0046 +213 +180 210021 022 035 004 03
213400 1622N 08320W 9785 00228 0043 +234 +180 210020 021 023 001 00
213430 1623N 08321W 9783 00230 0043 +237 +180 203017 018 015 000 03
213500 1624N 08322W 9778 00233 0043 +237 +180 203016 017 016 000 03
$$
Member Since: November 24, 2005 Posts: 628 Comments: 26465
Hm 01L kinda looks like OIL.
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Quoting IKE:


For a TD that's headed nowhere near Tampa....lol.


Don't forget about the oil it could send that way!
Member Since: June 16, 2010 Posts: 0 Comments: 28
TD1 finally!
Member Since: Posts: Comments:
Quoting JamesSA:
The highest one I saw posted was 41kts.


There was a 43 in there
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2511. hydrus
Quoting ElConando:
So it begins.
For some reason I feel a little older since this whole thing began....:)
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2510. SirCane
Quoting Tazmanian:
sure dos not look like a TD to me


LOL you gotta be kidding me. TD's are not Hurricanes.
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I can finnaly go home now and have that drink (or two).....Now, how big will the circulation be and will it have time to consolidate some before heading onto the Yucatan, or, miss it and get through the Channel if it intensifies over the next 24 hours?......See Yall Later Tonight.
Member Since: August 8, 2006 Posts: 0 Comments: 8311
Quoting StormW:
Never mind...just came back up...anybody else notice, or is it just me...that a lot of these sites are acting wierd?

everythings been on the fritz today. Facebook, Twitter, etc. Not sure if it's World Cup related traffic or not
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I said 4 days ago that we'd have a TD at 6PM EST on Friday.
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Quoting Ameister12:

We got TD 1!


I walk away from the computer for 3 MINUTES and this happens. WOW. Figures!

BEGIN
NHC_ATCF
invest_RENUMBER_al932010_al012010.ren
FSTDA


169N, 829W, 30, 1005
Member Since: Posts: Comments:
2504. Levi32
The center is farther south than we thought it was earlier. If this doesn't gain much latitude before reaching the Yucatan the ECMWF may not be so crazy after all, but I still think it's too far south. A curve of some sort to the north should happen in the gulf, but how much of a curve and where its eventual landfall will be on the west gulf coast remains to be determined.
Member Since: November 24, 2005 Posts: 628 Comments: 26465
Quoting IKE:


For a TD that's headed nowhere near Tampa....lol.


How else can they scare us all to death and drive ratings?
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TD#1 Navy site
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2501. gator23
Quoting CaneWarning:
Wow, the Tampa news station is doing a "Breaking News Alert" for the TD already. LOL

proof nothing exciting happens in Tampa.
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That storm system is truly remarkable in size for June. Absolutely amazingly BIG!
Member Since: June 16, 2010 Posts: 0 Comments: 28
2499. Patrap
Oil-Zilla...!



Member Since: July 3, 2005 Posts: 415 Comments: 125752
TD 1 on FNMOC
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Quoting ShenValleyFlyFish:


I was napping. Anything of note happened in the last couple of hrs. See Levi and Drak have declaired a TD. Now if we can just get the NHC and Orca on board it should be official


Looks like the Navy joined the throng; only a matter of time, though no Vortex Msg has been issued...it's pretty certain based on obs that the circulation is closed
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2496. cg2916
Quoting CaneWarning:
IKE can't post 0-0-0 now.


Actually he can, it's not named yet, though it will be soon. It's now 1-0-0-0.
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What is the Navy website that you guys are looking at??? Thanks
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Quoting IKE:


If it's still just a depression I can....but it will make TS strength before it gets torn up over land.


Oh, it'll be a TS tonight.

You may want to post 0-0-0 while you still can!
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2492. xcool
CaneWarning lol yep
Member Since: September 26, 2009 Posts: 2 Comments: 15603
2491. gator23
Quoting Levi32:
We have TD 1 or TS Alex


invest_RENUMBER_al932010_al012010.ren

WE HAVE CYCLONE GENESIS I REPEAT WE HAVE CYCLONE GENESIS. Happy new hurricane season.

Should Old Hurricanes be forgot,
and never thought upon;
The flames of Love extinguished,
and fully past and gone:
Is thy sweet Heart now grown so cold,
that loving Breast of thine;
That thou canst never once reflect
on Old long syne.
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And they err on the conservative side. Best looking TD I have seen in a long time ;)
Member Since: July 17, 2008 Posts: 0 Comments: 1242
2489. IKE
Quoting CaneWarning:
Wow, the Tampa news station is doing a "Breaking News Alert" for the TD already. LOL


For a TD that's headed nowhere near Tampa....lol.
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yesterday dr. m said that he did NOT think 93L, our now TD1 or TS Alex, would make it hurricane strength. Do you think this is still the case?
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2487. cg2916
L, 01, 2010062518, , BEST, 0, 169N, 829W, 30, 1005, TD,
Member Since: Posts: Comments:
I think the Monterey site is in the process of renumbering since they just pulled all the data off of 93L!
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2484. IKE
Quoting CaneWarning:
IKE can't post 0-0-0 now.


If it's still just a depression I can....but it will make TS strength before it gets torn up over land.
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Wow, the Tampa news station is doing a "Breaking News Alert" for the TD already. LOL
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Quoting nrtiwlnvragn:
06/25/2010 09:25PM 3,473 invest_RENUMBER_al932010_al012010.ren

We got TD 1!
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sure dos not look like a TD to me
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2480. Patrap
18z Early Cycle NHC model tracks
Invest93
Statistical/Simple Models (CLIPER,BAMs,LBAR,other Statistical Models)





Dynamic Models (More sophisticated models)




Early Model Wind Forecasts

Member Since: July 3, 2005 Posts: 415 Comments: 125752
I think the NHC will formulate their best track for the time being and when the 00Z model runs have a good handle on this system it may be revised
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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.