Tropical Storm Erika's future highly uncertain

By: Dr. Jeff Masters , 2:21 PM GMT on September 02, 2009

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The tropical wave we were calling Invest 94 finally decided to stop dawdling and become Tropical Storm Erika yesterday. However, Erika seems intent upon keeping us guessing about its intentions, as the storm's future track and intensity remain highly uncertain. After a modest burst of intensification to a 60 mph tropical storm last night, Erika has become quite disorganized this morning. The Hurricane Hunters found multiple swirling centers inside Erika early this morning, and the main center took a jump to the southwest to relocate itself under a batch of intense thunderstorms. The exact location and path of Erika remain uncertain at this point, and it is possible the storm will have another center relocation later today. Wind shear analyses from the University of Wisconsin diagnose a moderate 10 - 15 knots of shear over Erika, a decrease from yesterday. SSTs are warm, 29°C. Why, then, is Erika so disorganized? The trouble with the various wind shear analyses we use is that they take a crude average of winds over a thick layer to arrive at an average shear, and this large-scale average shear does not capture thin layers of shear that can dramatically affect a tropical cyclone. Upper air data from Guadeloupe and Saint Martin from last night show a complicated shear pattern in Erika's region, with 30 knot winds out of the south to southwest at 200 mb height, nearly calm winds between 300 - 500 mb, and northeasterly winds of 10 - 20 knots from the surface to 500 mb. Some extremely dry air with humidities near 10% was present in a thin layer near 600 mb on the Guadeloupe sounding, so dry air from the Saharan Air Layer is probably being injected by a northeasterly jet of wind into the core of Erika. The shear of 30 knots at the top of the storm is ripping away the heat and moisture Erika's thunderstorms are lifting there, and the result of the shear and dry air is a very disorganized tropical storm.

Erika is embedded in a weak steering current pattern, and the future track of the storm will depend greatly upon how strong the storm gets over the next few days. A stronger Erika will extend higher into the atmosphere and be steered more to the northwest by upper-level winds. A weaker Erika will be steered more by the low-level winds, which will keep the storm on a more westerly track. Given the complicated nature of the wind shear pattern in the region, it is difficult to forecast how strong Erika will get. Virtually anything can happen over the next five days, from dissipation (as forecast by the ECMWF model) to intensification to a Category 3 hurricane (as forecast by the HWRF model). Large-scale wind shear is expected to increase to 20 - 25 knots between 3 - 4 days from now, so Erika will have to deal with an increasing amount of adversity. The storm is a long-term threat to the Bahamas and U.S. East Coast, particularly if the storm stays weak over the next three days. Potential landfall solutions from the models range from Florida on Tuesday (GFS model) to North Carolina on Wednesday (Canadian model).


Figure 1. Morning image of Tropical Storm Erika, showing a false center over Guadaloupe--one of several surface swirls the Hurricane Hunters found in the storm.

Elsewhere in the tropics
The tropical wave off the coast of Africa we were watching on NHC's Tropical Weather Outlook as having a low chance of developing into a tropical depression has been done in by the dry air of the Sahara, and is no longer a threat to develop. A large and well-organized tropical wave will emerge from the coast of Africa on Thursday, and several of the models develop this low into a tropical depression by early next week. The remains of an old cold front off the coast of North Carolina could serve as a breeding ground for some tropical development Friday or Saturday, but anything that forms in this region would get swept quickly northeastward into New England by Sunday without enough time to become a tropical depression.

Hurricane Jimena nears Baja
Hurricane Jimena has steadily weakened over the past day, and is now down to a Category 2 hurricane with 105 mph winds. The storm should continue to steadily weaken over the next 24 hours as the waters under the hurricane cool from 28°C to 27°C. Jimena is battering a relatively unpopulated stretch of coast, and largely spared the tourist mecca on the southern tip of Baja. It now appears unlikely that moisture from Jimena will reach the Southwestern U.S., and the hurricane appears poised to stall out over Baja and die five days from now.


Figure 2. Hurricane Jimena on Tuesday, Sep. 1, 2009, as seen by NASA's MODIS instrument. Image credit: NASA Earth Observatory.

Baja's hurricane history
The most powerful hurricane on record to hit the west coast of Baja occurred last year, when Hurricane Norbert made landfall on the central Baja coast with sustained winds of 105 mph (Category 2) . Norbert's central pressure of 956 mb at landfall made it the 3rd strongest hurricane to hit the Pacific coast of Mexico since record keeping began in 1949. Norbert killed eight, knocked out power to 20,000 homes, and damaged or destroyed 40% of the homes on the islands of Margarita and Magdalena. Norbert crossed the Baja Peninsula and made landfall on Mainland Mexico as a Category 1 hurricane with 85 mph winds.

Only two major hurricanes have made landfall on Baja since record keeping began in 1949. Both hurricanes hit the east (Gulf of California) side of Baja. The first was Hurricane Olivia of 1967. Olivia made landfall on October 13, 1967 as a Category 3 hurricane with 125 mph winds. Due to its small size and the unpopulated region of coast it hit, damage was minimal. The second major hurricane was Hurricane Kiko, which made landfall on August 27, 1989, as a Category 3 hurricane with winds of 115 mph (minimal Category 3). Kiko was a small hurricane and hit a relatively unpopulated area, resulting in no loss of life and only scattered reports of damage.


Figure 3. A plot of all the major hurricanes to pass within 200 miles of Mexico's Baja Peninsula since 1949. Image credit: NOAA Coastal Services Center.

California fire webcams
As I discussed in yesterday morning's post, you can use our wundermap for Los Angeles with the fire layer turned on to see where the fire and smoke are located, and track the temperatures and winds during today's air pollution event. We also have two webcams with views of the fire: Altadena and Tujunga.

I'll have an update by 4pm this afternoon, when the data from the next hurricane hunter flight into Erika will be available.

Jeff Masters

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I wonder if a new center could form near the new burst of convection around 17N 59W.... What do you think? ... Vis Loop
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bocawind I am with you until there are no clouds in the sky or the system is north of me I do not stop watching and monitoring them. I have a 15 month old and 2 dogs so I can't make last minute decisions. I have been through Francis, Jeane and Wilma. 3 too many for me :)
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1059. IKE
Looking at a floater on Erika and the coordinates the NHC lists, I see where they say the COC is at...it's the naked swirl heading, what looks like, south of west from that island.
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I'm confused. Sorry if someone else has asked this question...

Why does the NHC have Erika as a TD at 120 hrs but the intensity models all range from 75-90 knots?
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1057. Drakoen
Erika is centered a bit to the north and east of the NHC coordinates
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So again I'll ask about the virus cause I'm not a computer tech - I'm getting the virus message only when I pull up this site or refresh it. Can I or do I need to do anything (note: sarcastic answers will be ignored) :) Thanks
Member Since: September 5, 2007 Posts: 0 Comments: 3488
1055. Seastep
964 IKE -

LOL.

Quote's not working for me for some reason now.
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what is the little green dot near the center of the red blob in the latest funktop loop?
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Quoting BurnedAfterPosting:
recon just found winds of 54mph at the surface


Looks sort of suspect though considering the other readings. Could be a gust or something.
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1052. Relix
Quoting BurnedAfterPosting:
recon just found winds of 54mph at the surface


Where?
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Quoting JupiterFL:


Who's on first?
Exactly
Member Since: August 18, 2008 Posts: 0 Comments: 474
Quoting CybrTeddy:
Vortex Message doesn't support current intensity.

Flight level winds were 23 knots, the SFMR was 40 knots.


The SMFR might be off... In shallow water (i.e. near the islands) the SMFR can show much higher winds speeds than are actually valid thanks the wave action.
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1049. Relix
Quoting Cotillion:
02/1745 UTC 16.0N 62.1W T1.5/2.5 ERIKA -- Atlantic

Really struggling.

Final T# Adj T# Raw T#
(3hr avg)
2.7 2.5 2.2


As weak as it was when it was an invest. Wow =P
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recon just found winds of 54mph at the surface
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Norman Anitvirus.
Member Since: June 30, 2008 Posts: 0 Comments: 15
Quoting TreasureCoastFl:

isn't that what he said.. the center is east of the airport?


Who's on first?
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02/1745 UTC 16.0N 62.1W T1.5/2.5 ERIKA -- Atlantic

Really struggling.

Final T# Adj T# Raw T#
(3hr avg)
2.7 2.5 2.2
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Quoting SQUAWK:


We had McAfee on the corp machines here and it was awful. Support was even worse.

McAfee = McCrappy. Its almost as much of bloatware as Norton, but it is just as ineffective. But as flood mentioned, if you are on a corporate network, your choices are limited, and you are best off following common sense.
Member Since: August 3, 2008 Posts: 16 Comments: 5890
Quoting Weather456:


no...not for weak systems...it was the same case for Danny.


So does that mean there is still a likelyhood of further development?
1042. Relix
Those winds over the center are quite pathetic. Erika will probably struggle until she's over the caribbean, and even then that will be hard. She could barely survive, it depends on where she hits.
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My greatest fear is that this thing will survive all adversity, than pop up over the bath waters between Cuba and the Bahamas, charge up to cat 4, slam my house in Boca Raton (south Palm Beach co.) than ride up the coast...

I have already tasted Frances and Wilma's eyewalls, and that was enough for me! (With Wilma, I was in the closet with a mattress over my head)

I don't count any of these systems out until they are well north of me...
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Quoting keys33070:



Is that normal?


no...not for weak systems...it was the same case for Danny.
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1039. Patrap
.." Im so Confused..?"

Sigh
Member Since: July 3, 2005 Posts: 426 Comments: 129089
Quoting Weather456:


yea the strongest winds seem well away from the center.



Is that normal?
Vortex Message doesn't support current intensity.

Flight level winds were 23 knots, the SFMR was 40 knots.
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Quoting BurnedAfterPosting:


oh wait nevermind, you said at the center

the highest surface winds so far is 40mph


yea the strongest winds seem well away from the center.
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1035. IKE
Quoting chevycanes:
Ike said the center of Erika is east of the airport yet the airport has a SE wind. if Erika had a defined circulation that airport should have a west wind.


You're right about that. I hadn't thought about that.
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Quoting BurnedAfterPosting:


It says 40mph winds, that is still a TS


A TS by 1 mph AND with a tilted circulation having the flight level center S of the surface low by 12 miles.
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Quoting Weather456:


how can something located at 61.5W be located east of something located at 61.1W. The airport is on Guadeloupe which is west of Erika's center.

isn't that what he said.. the center is east of the airport?
Member Since: August 18, 2008 Posts: 0 Comments: 474
Quoting Weather456:
Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 2nd day of the month at 18:13Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 309)
Storm Number & Year: 06L in 2009
Storm Name: Erika (flight in the North Atlantic basin)
Mission Number: 3
Observation Number: 03
A. Time of Center Fix: 2nd day of the month at 17:49:10Z
B. Center Fix Coordinates: 16°38'N 60°50'W (16.6333N 60.8333W)
B. Center Fix Location: 74 miles (118 km) to the NE (53°) from Basse Terre, Guadeloupe (FRA).
C. Minimum Height at Standard Level: 742m (2,434ft) at 925mb
D. Estimated (by SFMR or visually) Maximum Surface Wind: 35kts (~ 40.3mph)
E. Location of the Estimated Maximum Surface Wind: 93 nautical miles (107 statute miles) to the NW (314°) of center fix
F. Maximum Flight Level Wind Inbound: From 67° at 28kts (From the ENE at ~ 32.2mph)
G. Location of Maximum Flight Level Wind Inbound: 63 nautical miles (72 statute miles) to the NW (314°) of center fix
H. Minimum Sea Level Pressure: 1007mb (29.74 inHg) - Extrapolated
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 23°C (73°F) at a pressure alt. of 458m (1,503ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 23°C (73°F) at a pressure alt. of 458m (1,503ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 19°C (66°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Not Available
M. Eye Shape: Not Available
N. Fix Determined By: Penetration, Wind and Pressure
N. Fix Level: 925mb (If this vortex is from mid 1990's or earlier 925mb might be incorrect. See note.)
O. Navigation Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 5 nautical miles
Remarks Section:
Maximum Flight Level Wind: 28kts (~ 32.2mph) in the northwest quadrant at 17:27:40Z
Sea Level Pressure Extrapolation From: 925mb
Displacement of Sfc. Center From Flt. Lvl. Center: Surface center is 10 nautical miles (12 statute miles) to the N (360°) from the flight level center


Condensed version

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1030. SQUAWK
Quoting Floodman:


I used it in corporate environments for the better part of 12 years and had no issues; Norton on the other hand...well, let's just ssay you buy a new machine install the prog and lose 25% of your overhead...LOL

It mahy have been the way ot was configured; the "groupware" was a little tricky to config...we use it here (I run IT for my company) and we haven't had a problem inside the firewall...now, when assets go outside and the person wants to be free and easy browsing, then I get problems


Makes sense. We do a lot of heavy graphics and the overhead for McAfee was killing us. Switched to Trend and machines are much faster now and we have had no issues of late.
Member Since: December 9, 2008 Posts: 0 Comments: 2498
Quoting Weather456:
TD winds at the center


oh wait nevermind, you said at the center

the highest surface winds so far is 40mph
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TD winds at the center
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1027. WXHam
I thought that lat/long was for the false center?
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Ike said the center of Erika is east of the airport yet the airport has a SE wind. if Erika had a defined circulation that airport should have a west wind.
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Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 2nd day of the month at 18:13Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 309)
Storm Number & Year: 06L in 2009
Storm Name: Erika (flight in the North Atlantic basin)
Mission Number: 3
Observation Number: 03
A. Time of Center Fix: 2nd day of the month at 17:49:10Z
B. Center Fix Coordinates: 16°38'N 60°50'W (16.6333N 60.8333W)
B. Center Fix Location: 74 miles (118 km) to the NE (53°) from Basse Terre, Guadeloupe (FRA).
C. Minimum Height at Standard Level: 742m (2,434ft) at 925mb
D. Estimated (by SFMR or visually) Maximum Surface Wind: 35kts (~ 40.3mph)
E. Location of the Estimated Maximum Surface Wind: 93 nautical miles (107 statute miles) to the NW (314°) of center fix
F. Maximum Flight Level Wind Inbound: From 67° at 28kts (From the ENE at ~ 32.2mph)
G. Location of Maximum Flight Level Wind Inbound: 63 nautical miles (72 statute miles) to the NW (314°) of center fix
H. Minimum Sea Level Pressure: 1007mb (29.74 inHg) - Extrapolated
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 23°C (73°F) at a pressure alt. of 458m (1,503ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 23°C (73°F) at a pressure alt. of 458m (1,503ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 19°C (66°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Not Available
M. Eye Shape: Not Available
N. Fix Determined By: Penetration, Wind and Pressure
N. Fix Level: 925mb (If this vortex is from mid 1990's or earlier 925mb might be incorrect. See note.)
O. Navigation Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 5 nautical miles
Remarks Section:
Maximum Flight Level Wind: 28kts (~ 32.2mph) in the northwest quadrant at 17:27:40Z
Sea Level Pressure Extrapolation From: 925mb
Displacement of Sfc. Center From Flt. Lvl. Center: Surface center is 10 nautical miles (12 statute miles) to the N (360°) from the flight level center
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Quoting SQUAWK:


We had McAfee on the corp machines here and it was awful. Support was even worse.


i know fully well about that...we still have it here at the office and it sucks !!!
Member Since: August 18, 2009 Posts: 0 Comments: 201
Quoting forestwedder:
Just had the first rubble of thunder here in Dominica. Have been having some light showers coming in from the WSW for the last few hours. Sounds like the heavier stuff is around the corner. Wish the forward speed would pick up. I fear the rain damage in these mountains.



I haven't read any updates lately. How much rain do they expect you guys to get?
Quoting jeffs713:

Avast is free for virus scanning.

Also, if you want something other than Eudora, I suggest Thunderbird.

And finally... Firefox with NoScript will block most of the java ads unless you manually accept it.

yup, I have Firefox and Thunderbid ;)
Member Since: August 18, 2008 Posts: 0 Comments: 474
Quoting SQUAWK:


We had McAfee on the corp machines here and it was awful. Support was even worse.


I used it in corporate environments for the better part of 12 years and had no issues; Norton on the other hand...well, let's just say you buy a new machine install the prog and lose 25% of your overhead...LOL

It may have been the way it was configured; the "groupware" was a little tricky to config...we use it here (I run IT for my company) and we haven't had a problem inside the firewall...now, when assets go outside and the person wants to be free and easy browsing, then I get problems
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Just had the first rubble of thunder here in Dominica. Have been having some light showers coming in from the WSW for the last few hours. Sounds like the heavier stuff is around the corner. Wish the forward speed would pick up. I fear the rain damage in these mountains.
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Quoting IKE:


Here's the coordinates of the airport...Lat/Lon: 16.3%uFFFD N 61.5%uFFFD W

Erika is centered at 16.2N and 61.1W. Center is east of the airport.


how can something located at 61.5W be located east of something located at 61.1W. The airport is on Guadeloupe which is west of Erika's center.
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Quoting keys33070:
I am not on here everyday, but I have seen bloggers on here today being very childish. It is unbelieveable to me that adults are acting worst than my 3 and 4 yr olds. "I'm tellin on you" I'm gonna get you in trouble". Please grow up, and report people who need to be reported. Or better yet if you just can't help yourself don't brag when you do report someone. Or you can report yourself for letting us all know you reported someone ---- because guess what ----ready----
YOU ARE NO LONGER ON TOPIC!!!!

Sorry to anyone who this does not pertain to.


OMG so true and so awesome lol
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Erika looks horrible today. shear and dry air has been doing a number on her. she'll need another blow up of convection over her center soon or there might not be much left once she's in the SE Bahamas.
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If the storm misses florida completely and into the GOM it will be no more than a strong TS or minimal hurricane; however if it track a little more to the north it has enough warm water and ocean distance to become a CAT 2-3
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Quoting keys33070:
I am not on here everyday, but I have seen bloggers on here today being very childish. It is unbelieveable to me that adults are acting worst than my 3 and 4 yr olds. "I'm tellin on you" I'm gonna get you in trouble". Please grow up, and report people who need to be reported. Or better yet if you just can't help yourself don't brag when you do report someone. Or you can report yourself for letting us all know you reported someone ---- because guess what ----ready----
YOU ARE NO LONGER ON TOPIC!!!!

Sorry to anyone who this does not pertain to.


LOL...well said!
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1013. SQUAWK
Quoting Floodman:


All great until you're using a corporate asset, then you;re kinda stuck. For me however, I would change the AVG to McAfee...


We had McAfee on the corp machines here and it was awful. Support was even worse.
Member Since: December 9, 2008 Posts: 0 Comments: 2498
I am not on here everyday, but I have seen bloggers on here today being very childish. It is unbelieveable to me that adults are acting worst than my 3 and 4 yr olds. "I'm tellin on you" I'm gonna get you in trouble". Please grow up, and report people who need to be reported. Or better yet if you just can't help yourself don't brag when you do report someone. Or you can report yourself for letting us all know you reported someone ---- because guess what ----ready----
YOU ARE NO LONGER ON TOPIC!!!!

Sorry to anyone who this does not pertain to.
Quoting WXHam:


Depends on which party you belong to


thats good one
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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.

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