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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2279. Relix
Fellas, I am sure we have our first TS of the season. Cheers. Now let's watch this guy, it wants to be an evil system =(
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Quoting Levi32:
I have no doubt it's closed now.


20 knot west winds.
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2275. Levi32
This is a tropical depression and possibly a storm.
Member Since: November 24, 2005 Posts: 635 Comments: 26701
Quoting Levi32:
I have no doubt it's closed now.



I think that last 1004.3 could come out as a Vortex message ... its very close.
Member Since: October 1, 2007 Posts: 81 Comments: 26516
41 knot SFMR
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YAY YAY YAY PARTY PARTY PARTY YAY YAY YAY
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Quoting Tazmanian:
new poll


A TD

or B TS


B. TS
Member Since: Posts: Comments:
2269. Patrap

"You're The Storm"

oh it's healing - bang bang bang
i can hear your cannons call
you've been aiming at my land
your hungry hammer is falling

and if you want me I'm your country

I'm an angel bored like hell
and you're a devil meaning well
you steal my lines and you strike me dumb
come raise your flag upon me

and if you want me I'm your country
if you win me I'm forever - oh yeah!

'cause you're the storm that I've been needing
and all this peace has been deceiving
I like the sweet life and the silence
but it's the storm that I believe in

come and conquer and drop your bombs
cross my borders and kill the calm
bear your fangs and burn my wings
I hear bullets singing

and if you want me I'm your country
if you win me I'm forever - oh yeah!

'cause you're the storm that I've been needing
and all this peace has been deceiving
I need some wind to get me sailing
so it's the storm that I believe in

you fill my heart, you keep me breathing
'cause you're the storm that I believe in

and if you want me I'm your country
Member Since: July 3, 2005 Posts: 428 Comments: 129903
Quoting extreme236:
2239.

There we go! That should be enough.
Agreed. Watch out for the renumber.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
2267. Levi32
Quoting HurricaneSwirl:


16 kt west wind? This should be renumbered very soon.


23kt flight-level 41kt SFMR.
Member Since: November 24, 2005 Posts: 635 Comments: 26701
2266. Skyepony (Mod)
Haven't seen a dropsonde with that last fix.
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2265. Drakoen
Finally we have solid some west winds..
Member Since: October 28, 2006 Posts: 57 Comments: 30833
new poll


A TD

or B TS
Member Since: Posts: Comments:
How low do you think pressure will be at 11:00PM and 5:00AM?
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http://www.nhc.noaa.gov/gtwo/gtwo_atl_sub.shtml?area1#contents
NHC gives it a 80% chance of development.
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Nope short of my 18kt w wind requirement no TD till then.
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Quoting Floodman:


They're like...well, you know what they're like...there's some of those here too...

Speaking of opinions, has anyone seen Jedkins today? LOL



rofl....you are really being a funny man today!
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2259. Levi32
I have no doubt it's closed now.

Member Since: November 24, 2005 Posts: 635 Comments: 26701
Good afternoon!

Waiting for 93L's classification reminds me of waiting for Ana's classification last year. Right now, I'm going to make the same call that I did with Ana and say that one of the following will happen:
a) A Special Tropical Weather Outlook will be issued at 6:30 p.m. if it is not classified as a depression.
b) A Special Advisory Pack will be issued at 6:30 p.m. if it is classified as a depression.

We shall see...
Member Since: Posts: Comments:
Quoting Levi32:
Bingo, there's our strong west winds.


000
URNT15 KNHC 252105
AF302 01AAA INVEST HDOB 39 20100625
205530 1628N 08359W 9782 00238 0051 242 180 323018 018 019 007 00
205600 1626N 08359W 9779 00241 0052 240 180 320017 018 024 008 00
205630 1625N 08359W 9782 00237 0051 245 180 315017 017 015 001 00
205700 1623N 08359W 9780 00240 0051 246 180 309018 018 013 001 00
205730 1621N 08359W 9781 00239 0051 248 180 307017 018 012 001 00
205800 1620N 08359W 9778 00242 0052 250 180 303016 017 007 001 00
205830 1618N 08359W 9781 00240 0053 251 180 300015 016 002 000 03
205900 1617N 08359W 9782 00240 0053 252 180 301016 016 004 000 00
205930 1615N 08359W 9778 00245 0055 241 180 288014 016 017 003 00
210000 1613N 08359W 9786 00235 0055 239 180 279017 020 020 005 00
210030 1612N 08359W 9774 00247 0056 226 180 275023 025 032 003 00
210100 1610N 08400W 9784 00237 0055 224 180 270022 023 036 009 00
210130 1609N 08400W 9777 00245 0057 215 180 272023 023 041 016 00
210200 1607N 08400W 9781 00241 0058 210 180 267022 024 038 015 00
210230 1606N 08400W 9781 00242 0058 220 180 256020 020 028 010 00
210300 1604N 08400W 9785 00239 0058 221 180 257016 019 025 007 00
210330 1603N 08400W 9781 00243 0059 215 180 253012 012 027 007 00
210400 1601N 08400W 9780 00245 0061 203 180 274011 011 036 013 00
210430 1600N 08400W 9779 00247 0061 221 180 290011 012 038 025 03
210500 1558N 08400W 9780 00248 0063 204 180 291017 018 043 022 03
$$
;


There we go
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2254. Drakoen
Finally some solid west winds
Member Since: October 28, 2006 Posts: 57 Comments: 30833
2252. JamesSA
Quoting 10Speed:
So ....

1. Do they take the chance and name 93L even though it might end up not qualifying for a name by the time the night's out?

2. Do they name it simply because of it's proximity to land?

3. Do they refrain from naming it because of the oil promoted media frenzy that's going transpire as soon as they name it?

4. Do they do their job and follow their own rules regarding naming?

I think they will just follow their protocols.
Member Since: August 17, 2009 Posts: 0 Comments: 579
Quoting StormW:


Yeah...I had to turn my speakers off.


lol
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2239.

There we go! That should be enough.
Member Since: August 2, 2007 Posts: 19 Comments: 19234
Quoting 10Speed:
So ....

1. Do they take the chance and name 93L even though it might end up not qualifying for a name by the time the night's out?

2. Do they name it simply because of it's proximity to land?

3. Do they refrain from naming it because of the oil promoted media frenzy that's going transpire as soon as they name it?

4. Do they do their job and follow their own rules regarding naming?


They name it when it meets the criteria for being given a name...it's really that simple
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Quoting Levi32:
Bingo, there's our west winds.


000
URNT15 KNHC 252105
AF302 01AAA INVEST HDOB 39 20100625
205530 1628N 08359W 9782 00238 0051 242 180 323018 018 019 007 00
205600 1626N 08359W 9779 00241 0052 240 180 320017 018 024 008 00
205630 1625N 08359W 9782 00237 0051 245 180 315017 017 015 001 00
205700 1623N 08359W 9780 00240 0051 246 180 309018 018 013 001 00
205730 1621N 08359W 9781 00239 0051 248 180 307017 018 012 001 00
205800 1620N 08359W 9778 00242 0052 250 180 303016 017 007 001 00
205830 1618N 08359W 9781 00240 0053 251 180 300015 016 002 000 03
205900 1617N 08359W 9782 00240 0053 252 180 301016 016 004 000 00
205930 1615N 08359W 9778 00245 0055 241 180 288014 016 017 003 00
210000 1613N 08359W 9786 00235 0055 239 180 279017 020 020 005 00
210030 1612N 08359W 9774 00247 0056 226 180 275023 025 032 003 00
210100 1610N 08400W 9784 00237 0055 224 180 270022 023 036 009 00
210130 1609N 08400W 9777 00245 0057 215 180 272023 023 041 016 00
210200 1607N 08400W 9781 00241 0058 210 180 267022 024 038 015 00
210230 1606N 08400W 9781 00242 0058 220 180 256020 020 028 010 00
210300 1604N 08400W 9785 00239 0058 221 180 257016 019 025 007 00
210330 1603N 08400W 9781 00243 0059 215 180 253012 012 027 007 00
210400 1601N 08400W 9780 00245 0061 203 180 274011 011 036 013 00
210430 1600N 08400W 9779 00247 0061 221 180 290011 012 038 025 03
210500 1558N 08400W 9780 00248 0063 204 180 291017 018 043 022 03
$$
;


41 kt west wind? This should be renumbered very soon.
Member Since: Posts: Comments:
Quoting Levi32:
Bingo, there's our west winds.


000
URNT15 KNHC 252105
AF302 01AAA INVEST HDOB 39 20100625
205530 1628N 08359W 9782 00238 0051 +242 +180 323018 018 019 007 00
205600 1626N 08359W 9779 00241 0052 +240 +180 320017 018 024 008 00
205630 1625N 08359W 9782 00237 0051 +245 +180 315017 017 015 001 00
205700 1623N 08359W 9780 00240 0051 +246 +180 309018 018 013 001 00
205730 1621N 08359W 9781 00239 0051 +248 +180 307017 018 012 001 00
205800 1620N 08359W 9778 00242 0052 +250 +180 303016 017 007 001 00
205830 1618N 08359W 9781 00240 0053 +251 +180 300015 016 002 000 03
205900 1617N 08359W 9782 00240 0053 +252 +180 301016 016 004 000 00
205930 1615N 08359W 9778 00245 0055 +241 +180 288014 016 017 003 00
210000 1613N 08359W 9786 00235 0055 +239 +180 279017 020 020 005 00
210030 1612N 08359W 9774 00247 0056 +226 +180 275023 025 032 003 00
210100 1610N 08400W 9784 00237 0055 +224 +180 270022 023 036 009 00
210130 1609N 08400W 9777 00245 0057 +215 +180 272023 023 041 016 00
210200 1607N 08400W 9781 00241 0058 +210 +180 267022 024 038 015 00
210230 1606N 08400W 9781 00242 0058 +220 +180 256020 020 028 010 00
210300 1604N 08400W 9785 00239 0058 +221 +180 257016 019 025 007 00
210330 1603N 08400W 9781 00243 0059 +215 +180 253012 012 027 007 00
210400 1601N 08400W 9780 00245 0061 +203 +180 274011 011 036 013 00
210430 1600N 08400W 9779 00247 0061 +221 +180 290011 012 038 025 03
210500 1558N 08400W 9780 00248 0063 +204 +180 291017 018 043 022 03
$$
;


So... does that mean TD?
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Great View of Landfall Link
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2243. KEEPEROFTHEGATE (Mod)
smmcdavid:
i would like to say iam sorry for yesterday
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1004.3 mb

WOW
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2241. Drakoen
Quoting Levi32:
Visible satellite is screaming "TD" at me.


Yea
Member Since: October 28, 2006 Posts: 57 Comments: 30833
Quoting StormW:


Yeah...I had to turn my speakers off.


LOL!

-Snowlover123
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2239. Levi32
Bingo, there's our strong west winds.


000
URNT15 KNHC 252105
AF302 01AAA INVEST HDOB 39 20100625
205530 1628N 08359W 9782 00238 0051 242 180 323018 018 019 007 00
205600 1626N 08359W 9779 00241 0052 240 180 320017 018 024 008 00
205630 1625N 08359W 9782 00237 0051 245 180 315017 017 015 001 00
205700 1623N 08359W 9780 00240 0051 246 180 309018 018 013 001 00
205730 1621N 08359W 9781 00239 0051 248 180 307017 018 012 001 00
205800 1620N 08359W 9778 00242 0052 250 180 303016 017 007 001 00
205830 1618N 08359W 9781 00240 0053 251 180 300015 016 002 000 03
205900 1617N 08359W 9782 00240 0053 252 180 301016 016 004 000 00
205930 1615N 08359W 9778 00245 0055 241 180 288014 016 017 003 00
210000 1613N 08359W 9786 00235 0055 239 180 279017 020 020 005 00
210030 1612N 08359W 9774 00247 0056 226 180 275023 025 032 003 00
210100 1610N 08400W 9784 00237 0055 224 180 270022 023 036 009 00
210130 1609N 08400W 9777 00245 0057 215 180 272023 023 041 016 00
210200 1607N 08400W 9781 00241 0058 210 180 267022 024 038 015 00
210230 1606N 08400W 9781 00242 0058 220 180 256020 020 028 010 00
210300 1604N 08400W 9785 00239 0058 221 180 257016 019 025 007 00
210330 1603N 08400W 9781 00243 0059 215 180 253012 012 027 007 00
210400 1601N 08400W 9780 00245 0061 203 180 274011 011 036 013 00
210430 1600N 08400W 9779 00247 0061 221 180 290011 012 038 025 03
210500 1558N 08400W 9780 00248 0063 204 180 291017 018 043 022 03
$$
;
Member Since: November 24, 2005 Posts: 635 Comments: 26701
Quoting StormW:


Yeah...I had to turn my speakers off.


LOL!!!!!!!!!!
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Quoting HurricaneKatrina:
Quite impressive. Looks like the models are right about the size. Hopefully its not the first ever oilcane.


It's huge! It dwarfs Cat. 3 Darby in size, that's for sure!

-Snowlover123
Member Since: Posts: Comments:
Good afternoon all... What did I miss today? It looks like a TD or TS to me. I haven't seen the images all day, but am struck by how organized this system has gotten!

BTW... The answer to that Quiz would be D (TD or TS at 8pm). If not that, then a near 100% chance of tropical development over the next 48 hours. If they close this thing off, then they will issue a special advisory at 8pm or sooner, with watches and warnings posted.
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Quoting smmcdavid:


Aha! I knew it... opinions ARE everywhere. :0


They're like...well, you know what they're like...there's some of those here too...

Speaking of opinions, has anyone seen Jedkins today? LOL
Member Since: Posts: Comments:
Gonna head home and take a break (drink), but the big question in my mind right now looking at the big picture, is, how "big" will this thing be....It's a very huge area of apparent circulation and agree with some of the comments that it will take a long time (if it is so inclined) for this thing to close off....That might explain some of the problems in terms of declaring a TD, at this relatively early juncture, in spite of how good it looks on the loops..............BBL later tonight to see how He looks.
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Quoting Snowlover123:


That is definitely TD strength. Millibars, that is.

-Snowlover123


1004 isn't definitely any strength, because it's all relative. 1004 mb is a hurricane if the pressures surrounding it are 1050. Certainly not saying that's the case, but..
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Quoting extreme236:
I'm not convinced on a TD until I see a vortex message.


Same.
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Quoting Orcasystems:
Time: 20:44:30Z
Coordinates: 16.5333N 83.4333W
Acft. Static Air Press: 977.4 mb (~ 28.86 inHg)
Acft. Geopotential Hgt: 237 meters (~ 778 feet)
Extrap. Sfc. Press: 1004.3 mb (~ 29.66 inHg)
D-value: -
Flt. Lvl. Wind (30s): From 289° at 4 knots (From the WNW at ~ 4.6 mph)
Air Temp: 24.3°C (~ 75.7°F)
Dew Pt: 18.0°C (~ 64.4°F)
Peak (10s) Flt. Lvl. Wind: 5 knots (~ 5.8 mph)
SFMR Peak (10s) Sfc. Wind: 7 knots (~ 8.0 mph)
SFMR Rain Rate: 0 mm/hr (~ 0 in/hr)
(*) Denotes suspect data


This one could get a Vortex Message, the wind directions are there
Member Since: October 1, 2007 Posts: 81 Comments: 26516

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