93L near tropical depression strength

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

Share this Blog
8
+

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

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 3479 - 3429

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 | 71 | 72 | 73 | 74 | 75Blog Index

I see we have TD 1.
Member Since: Posts: Comments:
Tornado forming live on ChaserTv.com right now. Stormchaser Steve Miller live in Nebraska
Member Since: Posts: Comments:
How come there were guys claiming record sst next to Louisiana, Alabama and MS coasts and the heat content doesn't supports it? Can somebody explain it? Thanks!
Member Since: Posts: Comments:
3475. uplater
Quoting weatherwart:


So, the red and yellow are the cold tops, the areas surrounding the center of circulation? Is that right?



As you can see from the vid that Patrap posted: the towers need not occur around the COC, but it is often a good indicator of where it might be. The colors represent gradients. Red is -70c, and yellow is -80c. Any Greyishness in that yellow is -90c, and that is some seriously heavy mojo for a TD.

Here is another color gradient than the one I posted before from GOES sat. in this the redder the colder.



Member Since: Posts: Comments:
Quoting IKE:


Moved .1N and .7W.

84.4W is about 240-250 miles from landfall.


RIP TD #1 LOL
Member Since: April 26, 2009 Posts: 3 Comments: 3667
extreme236, can you give me the link for the TAFB numbers?
Member Since: September 2, 2009 Posts: 130 Comments: 21032
Quoting IKE:


Moved .1N and .7W.

84.4W is about 240-250 miles from landfall.
Currently moving at 10 mph, so it should be there in 24 to 30 hours.
Member Since: September 2, 2009 Posts: 130 Comments: 21032
3470. IKE
Quoting extreme236:
SAB rose as high as the limits would allow for this cycle:

25/2345 UTC 16.7N 84.4W T2.0/2.0 01L -- Atlantic


Moved .1N and .7W.

84.4W is about 240-250 miles from landfall.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting Tazmanian:
TD 1 is heading for LA

I'm saving this and cooking a crow..ok down here our pest bird is a thrushy..what your address in case I have to send it??
Member Since: Posts: Comments:
The one problem with going over the Yucatan is the fact that it is relatively flat terrain. Kinda similar to Florida but wider. Remember how long Wilma's circulation stayed completely over the NE Yucatan peninsula and maintained major hurricane status? I think this storm may have to rely on upper level winds to really do it in.
Member Since: Posts: Comments:
Quoting Tazmanian:
OMG I SEE A EYE



It's the reflection on the screen. Didn't your mother tell you "don't sit so close you'll wreck your vision.
Member Since: Posts: Comments:
Quoting USSINS:


The system is maturing, very vertically stacked with good lower level convergence (inflow of moist air) in the base of the chimney and a stable flue for the air to vent from the chimney (upper level divergence) out into the top of the storm where the moist air will flow outwards and down - repeating the process, growing ususally as long as there is warm fuel below to help create the moisture lift and inflow, and as long as there is no heavy upper level shear to knock the top off the chimney. The high tops are indicative of an storm becoming even more well-organized and strenthening.


Yes, thank you. I think I understand the concept after watching the video and reading your helpful explanation. The hot tower is much like a big fuel chimney, correct?
Member Since: Posts: Comments:
Quoting extreme236:
SAB rose as high as the limits would allow for this cycle:

25/2345 UTC 16.7N 84.4W T2.0/2.0 01L -- Atlantic
WOW! Didn't expect SAB to raise it a full T-number. Let's see what TAFB brings us, probably 2.5.
Member Since: September 2, 2009 Posts: 130 Comments: 21032
Track wise this could pull a Hurricane Opal, which would seem to follow the GFDL. To early to tell though
Member Since: Posts: Comments:
SAB rose as high as the limits would allow for this cycle:

25/2345 UTC 16.7N 84.4W T2.0/2.0 01L -- Atlantic
Member Since: August 2, 2007 Posts: 19 Comments: 19234
Quoting hurrkat05:
korithe man i dont think so you know when alex goes over the yucatan which he will it will be influenced greatly by the terrain and will tear up the circulation..you tell me how alex misses the yucatan and ill say game on..


Yucatan is flat.
Member Since: Posts: Comments:
Quoting JamesSA:
It has to be a little scary doing recon flights into a storm at night.
Not when dealing with a relatively weak system like 01L, but when they send you to do those missions with strong hurricanes, then those are scary.
Member Since: September 2, 2009 Posts: 130 Comments: 21032
Even though 01L appears to be missing the greatest heat content, there is still some fairly juiced waters that must be crossed...


Member Since: Posts: Comments:
Quoting CaicosRetiredSailor:
Something about this url is disturbing...


http://www.nrlmry.navy.mil/tcdat/tc10/ATL/01L.ONE/


Like I say you can't beat Patrap to anything. He pointed out the 01L thing immediately after it was declaired.
Member Since: Posts: Comments:
so is it pretty much the opinion here that this will not affect the panhandle at all?
Member Since: Posts: Comments:
Quoting MrstormX:
What do you guys think 11:00, TS Alex?
Let's see what the satellite estimates bring us before making that conclusion. But honestly TS Alex is almost certain, maybe not by 11 PM but soon.
Member Since: September 2, 2009 Posts: 130 Comments: 21032
3452. JamesSA
Quoting MiamiHurricanes09:
The next reconnaissance aircraft will be departing at 2:00 UTC (or 10 PM EDT).
It has to be a little scary doing recon flights into a storm at night.
Member Since: Posts: Comments:
Quoting uplater:


The name is sorta Paradoxical. The Clouds reach so high up into the atmo, the air is very thin, and it gets super cold. They are really cold tops. in this case around -90c ( -130F ).



So, the red and yellow are the cold tops, the areas surrounding the center of circulation? Is that right?
Member Since: Posts: Comments:
Quoting hurrkat05:
well im not from texas but thats the best scenario a weak tropical storm hitting the middle or upper texas coast will not have any affect on oil here in la miss or alabama...alex once he hits the yucatan will be lucky if he does get out over the boc and develop into a weak tropical storm..i think he will stay a tropical depression the yucatan will do a number on alex..i would say people on the middle texas coast prepare for some much needed rain and some 40mph winds..no big deal..im so glad the trough won't be affecting alex that lets the northern gom off the hook..thank god for the yucatan pen..it saved us from a possible potent hurricane..
Well with all due respect, If this storm hits the Texas coast it will bring Oil not only to LA but MS, AL and FL will get the Oilly Mess.... Because of the counter clock wise movement the waves from the east side of the storm move north. So all the oil just to the south of FL,AL and MS will move north....

Taco :o(
Member Since: Posts: Comments:
3448. Michfan
Quoting centex:
This is not a SEP/OCT storm which will bend NE.


Thats what im trying to show so we can stop with the inevitable comparisons down the road.
Member Since: Posts: Comments:
What do you guys think 11:00, TS Alex?
Member Since: Posts: Comments:
3445. centex
This is not a SEP/OCT storm which will bend NE.
Member Since: Posts: Comments:
The next reconnaissance aircraft will be departing at 2:00 UTC (or 10 PM EDT).
Member Since: September 2, 2009 Posts: 130 Comments: 21032
Quoting drg0dOwnCountry:

01L One reads almost OIL One . addiction to oil is very very bad.


So is crack but I don't see either being abused less anytime soon.
Member Since: Posts: Comments:
3442. KEEPEROFTHEGATE (Mod)
Quoting MrstormX:


Thats bold of you lol, although Ican't rule it out with SSTs like this in the gulf.


it will be before the gulf
dmax tonight will be when it happens
to take us into the am
Member Since: Posts: Comments:
I know this is a little off the topic... but severe thunderstorms are occurring over Minnesota ATTM... Stormchaser Marcus Hicks is live feed from there on a tornadic supercell west of Mankato, MN. Go to chasertv.com
Member Since: Posts: Comments:
3372 weatherwart "Would one of you kind people please explain the meaning of a 'hot tower'?"

Wiki and YouTube's Nasa video
Member Since: Posts: Comments:
Quoting TropicalNonsense:



sunny and warm. ZERO influence from this system.
I never said it was going to happen, but you can't rule out a possibility.
Member Since: September 2, 2009 Posts: 130 Comments: 21032
well it took too 93L too get the 1st TD

round 1

90L bust

91L bust

92L bust

93L be comes TD 1

94L ????
Member Since: Posts: Comments:
3437. Michfan
http://cimss.ssec.wisc.edu/tropic/archive/2005/storms/wilma/wilma.html

For those wondering about the comparisons with this and Wilma. Wilma formed a bit farther north than TD1 and was picked up a lot stronger longwave trough than what is forecasted for TD1. She as also a bit more well developed at this stage too.



Don't go reading into it too much. Different time of year in regards to climatology in comparison to what were seeing now.
Member Since: Posts: Comments:
3436. HadesGodWyvern (Mod)
[UTC/Zulu - 4 = EST] for the recon flights information.
Member Since: Posts: Comments:
Quoting hurrkat05:
well im not from texas but thats the best scenario a weak tropical storm hitting the middle or upper texas coast will not have any affect on oil here in la miss or alabama...alex once he hits the yucatan will be lucky if he does get out over the boc and develop into a weak tropical storm..i think he will stay a tropical depression the yucatan will do a number on alex..i would say people on the middle texas coast prepare for some much needed rain and some 40mph winds..no big deal..im so glad the trough won't be affecting alex that lets the northern gom off the hook..thank god for the yucatan pen..it saved us from a possible potent hurricane..


This is premature.
Member Since: Posts: Comments:
Something about this url is disturbing...


http://www.nrlmry.navy.mil/tcdat/tc10/ATL/01L.ONE/

edit: I see 3429. drg0dOwnCountry noted the same.
Member Since: Posts: Comments:
I suspect that a season like 2005 has just started, not trying to sound like an alarmist but TD-1 is the key unlocking the Atlantic. 94L looks promising as well.
Member Since: Posts: Comments:
Quoting MiamiHurricanes09:
Considering you live in Tampa by your handle, I suggest that you contact the local weather service for much more accurate information. But I can tell you that if TD #1 does strengthen and moves a little more towards the panhandle it isn't out of the question that you could get some feeder bands and heavy rain from it.



sunny and warm. ZERO influence from this system.
Member Since: Posts: Comments:
Quoting TropicalNonsense:
I THOUGHT THIS DESERVED A RE-POST BEFORE I CHECK OUT.

FOOD FOR THOUGHT.... 18z 6-25-2010

I will be back on the blog later to talk about this, later on tonight and to check back in.

You guys take it easy and have a good one :)

The Blog is close to a Record Amount of posts pace wise so POST HARD TONIGHT!


What is the record then?
Member Since: Posts: Comments:
3430. USSINS
Quoting weatherwart:
Good evening. Would one of you kind people please explain the meaning of a "hot tower?"

Thanks!


The system is maturing, very vertically stacked with good lower level convergence (inflow of moist air) in the base of the chimney and a stable flue for the air to vent from the chimney (upper level divergence) out into the top of the storm where the moist air will flow outwards and down - repeating the process, growing ususally as long as there is warm fuel below to help create the moisture lift and inflow, and as long as there is no heavy upper level shear to knock the top off the chimney. The high tops are indicative of a storm becoming even more well-organized and strengthening.
Member Since: Posts: Comments:
Quoting Grothar:

01L One reads almost OIL One . addiction to oil is very very bad.
Member Since: Posts: Comments:

Viewing: 3479 - 3429

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 | 71 | 72 | 73 | 74 | 75Blog Index

Top of Page

About JeffMasters

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.