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: 1479 - 1429

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

1479. JLPR2
Quoting Baltimorebirds:
Yeah I know.I was talking about this system yesterday.The models do eventually develope this into a tropical storm.


I dont see how it will be able to do that, there's a wall of shear right in front of it
Member Since: Posts: Comments:
HEY GUYS THE HURRICANE HUNTER ARE NOT HEADING NORTH NOW AND THEY HAVE FOUND 35 MPH WIND SOMEONE WITH GOOGLE EARTH LOOKING ON RECON PLEASE POST
Member Since: Posts: Comments:
1477. IKE
Quoting YourCommonSense:


No popcorn?


I got some in the other cabinet....I'll stick a bag in my 15 year-old microwave....get my salt...freshen up my Coke and I'm set!
Member Since: Posts: Comments:
93L GOES overlaid onto SST's with currents

Member Since: Posts: Comments:
Quoting Tropicaddict:


So the HH are done with their trip? We are sure there's not TD?


oh no they will be there for several more hours I think
Member Since: Posts: Comments:
Good afternoon everyone.

Hurricane Celia is such a beautiful storm.
Member Since: Posts: Comments:
Quoting Patrap:


The ATCF Imagery is a good tool to see the model runs


Thanks, I'll check them out. I also use this link. All models in one handy spot. What's your opinion of the hwrf (self serving question, sorry, but I live in Clearwater and that one is the most eastern run yet)

Link
Member Since: Posts: Comments:
1471. IKE
Quoting Hurricanes101:


lol no TD at this time


It looked like a TD...what is it with the Atlantic? I hope it stays a non-TD, but 75% of systems in this basin struggle to get going.
Member Since: Posts: Comments:
Quoting IKE:
So no TD?

I've got a few extra towels if anyone needs one to wipe away the t e a r s......


So the HH are done with their trip? We are sure there's not TD?
Member Since: Posts: Comments:
Quoting Jeff9641:


Yep I've seen this happen so many times with Caribbean storms. Da bomb is about to go. I hope the mets in Tampa aren't still saying 93L will have no impact on them. LOL!


Is that before or after the asteroid hits?
Member Since: Posts: Comments:
1467. Patrap
Quoting Clearwater1:

I think the models you've posted daily have been fairly consistent, with a shift slightly eastward at the end of each one. Excluding the obvious west heading models. Very scary for central coast if they pans out. Stating the obvious I suppose.


The ATCF Imagery is a good tool to see the model runs
Member Since: July 3, 2005 Posts: 421 Comments: 127617
1466. JamesSA
So 30 knots was the highest wind they found, and nothing West? It is looking better visually but it isn't exactly 'Alex the Destroyer' yet.

Good. ..but I'm not taking my eyes off of it for too long.
Member Since: August 17, 2009 Posts: 0 Comments: 579
Quoting IKE:
So no TD?

I've got a few extra towels if anyone needs one to wipe away the t e a r s......
LMAO!
Member Since: September 2, 2009 Posts: 130 Comments: 21091
1464. JDSmith
Or at the very least, this thing will be a TD by a little later tonight.

There were two Pressure readings taken in the same spot within 20 min of each other. Pressure readings were down on the second pass and winds were up.

This thing is strengthening fast.
Member Since: Posts: Comments:
Quoting Hurricanes101:


lol no TD at this time


Just RI, that's all. It's still relatively weak.

RI better stop or RI may become RIP.
Member Since: Posts: Comments:
1462. brla61
Quoting StormW:


Welcome to da blog!


Thanks! I've been lurking since Gustav in 08. That was enough excitement for me. I'm praying La gets spared this year.
Member Since: Posts: Comments:
1461. IKE
Quoting itrackstorms:
Thanks for letting me down 93L



Can somebody pass me the Heinz 57 sauce?


Hang on....let me grab it out of the cabinet....there we go....
Member Since: Posts: Comments:
1460. Levi32
Quoting txag91met:


Low is already almost that far south, if this thing is exposed over the Yucatan, the low-level swirl will just move westward and miss the trough.


It won't become exposed if there is no wind shear. A WNW track into the Bay of Campeche is still on the table....a lot of things are still on the table, but I don't see it going quite that far south. That is just my opinion of course.
Member Since: November 24, 2005 Posts: 635 Comments: 26556
18:53:00Z 17.583N 82.583W 977.4 mb
(~ 28.86 inHg) 260 meters
(~ 853 feet) 1007.0 mb
(~ 29.74 inHg) - From 132° at 29 knots
(From the SE at ~ 33.3 mph) 21.8°C
(~ 71.2°F) 18.0°C
(~ 64.4°F) 30 knots
(~ 34.5 mph) 33 knots
(~ 37.9 mph) 4 mm/hr
(~ 0.16 in/hr) 31.9 knots (~ 36.7 mph)
110.0%
Member Since: September 2, 2009 Posts: 130 Comments: 21091
Quoting IKE:
So no TD?

I've got a few extra towels if anyone needs one to wipe away the t e a r s......


lol no TD at this time
Member Since: Posts: Comments:
Thanks for letting me down 93L



Can somebody pass me the Heinz 57 sauce?
Member Since: Posts: Comments:
1455. Grothar
93L and 94L. 94L is moving more northerly.

Member Since: Posts: Comments:
Quoting charlottefl:
Directly from Dr. M's blog entry today:

"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."


I really hate to point out the obvious... but I have to every year.

Mexico & Belize are country's also. The "landfall" is going to happen there long before anyone else gets hit.
Member Since: October 1, 2007 Posts: 81 Comments: 26511
Quoting Patrap:
Repost #1288

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




I think the models you've posted daily have been fairly consistent, with a shift slightly eastward at the end of each one. Excluding the obvious west heading models. Very scary for central coast if they pans out. Stating the obvious I suppose.
Member Since: Posts: Comments:
1452. IKE
So no TD?

I've got a few extra towels if anyone needs one to wipe away the t e a r s......
Member Since: Posts: Comments:
1451. jpsb
Beer time, see yall later.
Member Since: Posts: Comments:
recon found 37mph winds at 17.5 82.5
Member Since: Posts: Comments:
1449. JDSmith
Time: 18:54:30Z
Coordinates: 17.6167N 82.5167W
Acft. Static Air Press: 977.3 mb (~ 28.86 inHg)
Acft. Geopotential Hgt: 262 meters (~ 860 feet)
Extrap. Sfc. Press: 1006.9 mb (~ 29.73 inHg)
D-value: -
Flt. Lvl. Wind (30s): From 143° at 30 knots (From the SE at ~ 34.5 mph)
Air Temp: 23.5°C (~ 74.3°F)
Dew Pt: 18.0°C (~ 64.4°F)
Peak (10s) Flt. Lvl. Wind: 32 knots (~ 36.8 mph)
SFMR Peak (10s) Sfc. Wind: 19 knots (~ 21.8 mph)
SFMR Rain Rate: 0 mm/hr (~ 0 in/hr)
(*) Denotes suspect data

Looks like a TD to me.
Member Since: Posts: Comments:
You gulf coasters out there that want to see 93L become another Dolly better get on your knees right now and pray God that system stays weak for just 48 more hours.
Member Since: Posts: Comments:
Heading back to work. Catch you all later.
Member Since: Posts: Comments:
Quoting Jeff9641:


Tampa mets might want to rephrasize their forecast later today and not say Tampa is in the clear.


I'll see what they say later tonight.
Member Since: Posts: Comments:
Quoting Levi32:


The steering currents are very unlikely to remain westerly enough to force this nearly due west for the next 4 days into the very southern Bay of Campeche. A longwave trough passing by over the northern US will weaken the ridge enough to open up more southeasterly steering currents which will cause 93L to gain at least some latitude. A track into Mexico still can't be ruled out, but that far south on the 12z ECMWF? No way.


Low is already almost that far south, if this thing is exposed over the Yucatan, the low-level swirl will just move westward and miss the trough.
Member Since: Posts: Comments:
1443. Grothar
While the center may be moving more west, the system wants to move a little more North. Some models have been shifting to the East on each run.
Member Since: Posts: Comments:
1442. Drakoen
Quoting kmanislander:
The passes by the HH just go to show that many times when ASCAT appears to show a closed low it really isn't at all. There is no substitute for obs on location. That is why I always tend to lean against calling a closed low unless the sat. pass is crystal clear.


True
Member Since: October 28, 2006 Posts: 57 Comments: 29917
1441. JLPR2
Quoting btwntx08:

yea we know 94L lol we are focusing on the hurricane hunters in 93L


yeah I noticed LOL!
Well I guess someone had to mention 94L XD
Now, back to 93L
Member Since: Posts: Comments:
1439. IKE
Quoting TampaWeatherBuff:


If I had a dime for every time I heard this in the last three days, I'd be able to quit my day job.


Or...it will be a depression by....

Or...they may just skip TD and go right to TS!
Member Since: Posts: Comments:
Quoting bappit:


Moving more west than north right now I think.


If there is a westerly component to its slow track, then its proximity to land is hampering and weakening the system.
Member Since: Posts: Comments:
Quoting JLPR2:
So everyone knows we have 94L too right?

I just dont see it mentioned in the last pages :P


I sent 94L a nice "Wish You Were Here" note. I think people resent her apparent decision to go in the other direction.
Member Since: Posts: Comments:
1436. Patrap
93L has some big hips and its still consolidating that Cyclonic flow into a tighter CoC ...

The Surface winds are going take a lil while to feel her sway.

Esp that West inflow route.

So its a tozzup as to Calling the TD.

But 93L has a lotta potential to becoming a interest well heeded with the GOM tracks and the Oil spill.
Member Since: July 3, 2005 Posts: 421 Comments: 127617
1435. Levi32
Quoting txag91met:
Why? Explain your reasoning?


The steering currents are very unlikely to remain westerly enough to force this nearly due west for the next 4 days into the very southern Bay of Campeche. A longwave trough passing by over the northern US will weaken the ridge enough to open up more southeasterly steering currents which will cause 93L to gain at least some latitude. A track into Mexico still can't be ruled out, but that far south on the 12z ECMWF? No way.
Member Since: November 24, 2005 Posts: 635 Comments: 26556
Quoting JLPR2:
So everyone knows we have 94L too right?
I just dont see it mentioned in the last pages :P


We know, but it's not had us all watching with frustration for the past week, is only rated 20% for development as opposed to 80%, and given it's location, would seem to have fishspinner written all over it if it did develop so isn't such a concern to most...
Member Since: Posts: Comments:
1433. Grothar
Member Since: Posts: Comments:
anyone have a link for the gfdl run? I'm tired of waiting to see the results.
Member Since: Posts: Comments:
1430. myway
Quoting stormpetrol:
THe NHC is putting all interest in NW Caribbean on alert, I would bet a nickel against a bucket of cow manure that this will be classified before the day is through! This is a true tropical cyclone in the making, could turn out to be significant one too in my opinion.


Getting close enough to landmass to possibly warrant watches @ the 48hour out mark?
Member Since: Posts: Comments:
Directly from Dr. M's blog entry today:

"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."
Member Since: Posts: Comments:

Viewing: 1479 - 1429

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.

Local Weather

Partly Cloudy
60 °F
Partly Cloudy