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: 229 - 179

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

Quoting MiamiHurricanes09:
We would need a very consolidated closed low for a TS. Pressure is that of TS status but winds are only at 35mph.


Well it will be interesting to see how strong the HH find 93L. Based on the available data, it's organization isn't terribly impressive yet. 17:45utc numbers should be higher though.
Member Since: August 2, 2007 Posts: 19 Comments: 19234
Nevermind, I found it.
Member Since: Posts: Comments:
Thats the spirit Pat
Member Since: Posts: Comments:
Quoting Stormchaser2007:
We may get a special advisory if the HH finish up before 5pm.



Very true. They seem to issue those more frequently now.
Member Since: August 2, 2007 Posts: 19 Comments: 19234
Quoting Stormchaser2007:
We may get a special advisory if the HH finish up before 5pm.

It's possible.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
Quoting Jeff9641:
Forget TD we may Alex very soon.
We would need a very consolidated closed low for a TS. Pressure is that of TS status but winds are only at 35mph.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
BBL
I'll come back with popcorn
Member Since: Posts: Comments:
Shear maps.
http://cimss.ssec.wisc.edu/tropic/real-time/atlantic/winds/wg8shr.GIF

Tendency. Watch the area where 94L is in.
http://cimss.ssec.wisc.edu/tropic/real-time/atlantic/winds/wg8sht.GIF
Member Since: Posts: Comments:
Quoting RitaEvac:
Large storm, but not tight and coiled up which is good



In order for the NAM to be right, Jeff Masters would have to be somewhat wrong, as he only gives 94L a 10% chance of even being a hurricane.

***I'm all in with a flush showing. My opponent has two pair with the river coming. He's only got 4 outs, a 10% chance of getting the card that will give him a full house. And the RIVER CARD IS A !!!!!***
Member Since: Posts: Comments:
We may get a special advisory if the HH finish up before 5pm.

Member Since: Posts: Comments:
Seen Hell and High Water and the Saints win a Super Bowl in the Last 5 Years.

Whats a Lil oil gonna do?

pppfttt.
Member Since: Posts: Comments:
Quoting extreme236:


It would be very unlikely to see anything subtropical since the formation of this system is in part due to a tropical wave.
True.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
213. jpsb
Quoting MrsOsa:


Theoretically, yes they will pay. They didn't "buy" your house previously, they paid to fix it. So yes, they will pay to fix it again as long as your premiums were kept current. And then they will decline to renew your policy because you file too many claims.
thanks!
Member Since: Posts: Comments:
Quoting jasoniscoolman09:
I THINK 94L IS NOT GOING OUT TO SEA AT ALL. ITS WILL START TO MOVE BACK TO THE WEST ON SUNDAY AND HIT THE EAST COAST BY NEXT WEEKEND.


Why? BTW, your hand cramping or something?
Member Since: Posts: Comments:
Anyone with some guidance regarding monitoring the HH on Google Earth, please WU Mail me. TIA
Member Since: Posts: Comments:


Member Since: Posts: Comments:
Patrap you ready for oil...

Member Since: Posts: Comments:
Thanks for all your information guys. Being here just north of Grand Isle it is pretty hard not to worry if the storm will come, it's even harder to think that if it goes to our east, we will have more oil than we have now. :(
Member Since: Posts: Comments:
Quoting cg2916:
Miami, how many TCFA points does 93L have?
Believe it or not I got 65 points.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
203. ATL
Quoting wunderkidcayman:
I say 93L/pre-TD 1 will make a more northerly turn than what is forecasted maybe it never directly hit the yucatan and goes in between the yucatan and cuba maybe hitting the most western tip of cuba

Basis for this? All model guidance is pointing to a Yucatan crossing.
Member Since: Posts: Comments:
Quoting unf97:


Good observation. It is approaching the sheer zone and I highly doubt anything will come out of this invest, but, you never know. We have seen surprises occur out there in the past, so it will be montiored, but no major threat at this time.


If 94L survives the shear, which won't be that long of a period for 94L to go through, then the east coast bears watching. I'm keeping a close eye on the Burmuda high, any slight shift to the west could have future bonnie knocking at the carolinas doorstep.
Member Since: Posts: Comments:
I say 93L/pre-TD 1 will make a more northerly turn than what is forecasted maybe it never directly hit the yucatan and goes in between the yucatan and cuba maybe hitting the most western tip of cuba
Member Since: June 13, 2009 Posts: 2 Comments: 12180
Quoting MiamiHurricanes09:
Shear is forecasted to ease to the north of the system. Wouldn't be surprised to see something tropical or subtropical from 94L.


It would be very unlikely to see anything subtropical since the formation of this system is in part due to a tropical wave.
Member Since: August 2, 2007 Posts: 19 Comments: 19234
Large storm, but not tight and coiled up which is good

Member Since: Posts: Comments:
Quoting unf97:


Good observation. It is approaching the sheer zone and I highly doubt anything will come out of this invest, but, you never know. We have seen surprises occur out there in the past, so it will be montiored, but no major threat at this time.


Yes it is a good observation, but the shear is expected to ease up. Probably the reason why were even seeing 94L in the first place.
Member Since: August 2, 2007 Posts: 19 Comments: 19234
Quoting DocBen:
Could that 'extra' blob south of Haiti become 95L?


Great that means we will have 4 areas to watch.
Member Since: Posts: Comments:
Miami, how many TCFA points does 93L have?
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Hi,.Im Tony Hayward talking to you from Sweden where Im relaxing and Skiing with my Family.

We at BP have a Hurricane Response Plan Ready to Implement in case of a Hurricane or Tropical Storm Emergency.

Rest assured,..were going to make this right.

Member Since: Posts: Comments:
12Z NAM would push oil into the Lake. Scary!
Member Since: Posts: Comments:
Quoting sammywammybamy:



You Left out Everything thats in between .. You forgot: the Bahamas, Florida, gerogia, South and North carolina.


Uh, no. I did not leave anything out. Those areas will can never, will never, NEVER NEVER NEVER be affected by 94L. Study the maps. Look at the Bermuda High and factor in the trough coming in.

94L to even head WNW would be a freak.
Member Since: Posts: Comments:
Here comes the trough that HWRF is seein

Link
Member Since: Posts: Comments:
Quoting unf97:


Good observation. It is approaching the sheer zone and I highly doubt anything will come out of this invest, but, you never know. We have seen surprises occur out there in the past, so it will be montiored, but no major threat at this time.
Shear is forecasted to ease to the north of the system. Wouldn't be surprised to see something tropical or subtropical from 94L.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
Quoting cchsweatherman:


Way too soon in my opinion. Don't see the TUTT moving out that quickly.


One of the tropical discussions I read said 94 will push through the TUTT and be in the middle of that area where wind shear is low and then wind shear will increase as it exits out the other side. Not my wording, I didn't think systems could survive inside a TUTT.
Member Since: Posts: Comments:
179. unf97
Quoting weathermanwannabe:
Invest 94, while firing a good amount of convection, is about to run into a wall of 30-50 knots of sheer and right on the boundry and very close to the TUTT......I would not get too excited about this one at the moment.


Good observation. It is approaching the sheer zone and I highly doubt anything will come out of this invest, but, you never know. We have seen surprises occur out there in the past, so it will be montiored, but no major threat at this time.
Member Since: Posts: Comments:

Viewing: 229 - 179

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

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