Hawaii braces for Felicia; 99L near the Cape Verdes Islands may develop

By: Dr. Jeff Masters , 3:55 PM GMT on August 10, 2009

Share this Blog
4
+

A strong tropical wave (99L) is just south of the Cape Verdes Islands, 800 miles off the coast of Africa. This morning's QuikSCAT pass showed a nearly closed surface circulation, stretched out along one axis. The satellite saw winds of up to 45 mph in a band of heavy thunderstorms well south of the Cape Verdes Islands. The islands have seen winds of only 10 - 15 mph and some occasional rain showers thus far from the disturbance. Heavy thunderstorm activity associated with 99L died down this morning, but appears to be making a comeback late this morning. Wind shear is moderate, about 10 knots, and sea surface temperatures are moderately warm, about 27 - 28°C. There is a large area of dry air to 99L's north that is interfering with the storm's organization, though.


Figure 1. Current satellite image of disturbance 99L.

Wind shear is expected to be moderate, 5 - 15 knots, through Wednesday. SSTs will remain relatively constant at 27°C, but the dry, stable air of the Saharan AIr Layer (SAL) to 99L's north will be problem for it. NHC has given 99L a moderate (30 - 50% chance) of developing into a tropical depression by Wednesday morning, which is a reasonable forecast. Most of the models show some weak development, but none of them predict 99L will become a hurricane. It is too early to say if 99L will recurve north of the Lesser Antilles Islands or not, since it will be at least 5 days before the storm makes it that far. It is unusual, though, for storms forming this far north to make it all the way across the Atlantic to hit the Lesser Antilles Islands.

The GFS and ECMWF models are predicting the possible development of a new tropical wave coming off the coast of Africa late this week.

Felicia continues to weaken, but is a flash flooding threat to Hawaii
Tropical Storm Felicia has weakened steadily over the past 24 hours, thanks to cool sea surface temperatures and increasing shear. Recent satellite loops show that strong upper-level winds from the west have pushed the storm's heavy thunderstorm activity to the northeast side of the center, exposing the surface center as a swirl of low clouds. Felicia's relatively meager heavy thunderstorm activity is steadily moving away from the center of the storm.


Figure 2. History of hurricane activity over Hawaii since 1950. Hawaii islands have been hit by only 9 tropical cyclones of tropical depression or greater strength, with 4 others passing withing 75 miles of an island. Image credit: NOAA Coastal Services Center.

Sea surface temperatures (SSTs) under Felicia are 25°C, well below the 26°C threshold typically needed to sustain a hurricane. SSTs will slowly increase to 26°C by Tuesday. Wind shear has increased to a high 30 knots, and is expected to increase further to 40 knots by Tuesday. The high shear combined with the cool SSTs should continue to weaken Felicia today. I give a 30% chance that the shear will completely rip away Felicia's heavy thunderstorm activity by the time the storm reaches Hawaii, leaving only a swirl of low-level clouds that will not cause significant flooding problems. The wind speed probabilities forecast shows about a 25% chance Felicia will still be a weak tropical storm at 3 am Hawaiian time Tuesday morning, and a 15% chance the storm will have dissipated. If Felicia does hold together that long, it would be only the tenth tropical cyclone of tropical depression or higher strength to affect the islands since 1950 (Figure 2). Large swells from Felicia are already affecting the Big Island, and a high surf warning has been posted for east-facing shores of the Big Island and other Hawaiian islands. Felicia or its remnants may bring heavy rain, flash flooding, and mud slides to the islands beginning this afternoon, and a Flash Flood Watch has been posted for most of the islands.

Links to follow:
Long range radar from the Big Island
Wundermap for Hawaii

I'll have an update Tuesday morning.

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: 2839 - 2789

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 | 66Blog Index

Quoting HadesGodWyvern:
yes ship based TC Guidance intensities


The 12Z run should give a better idea, since it will use the official NHC track. Currently it uses BAMM which recurves rather quickly. However the NHC may show a similar track, have to wait and see.
Member Since: Posts: Comments:
2838. HadesGodWyvern (Mod)
yes ship based TC Guidance intensities
Member Since: Posts: Comments:
Quoting HadesGodWyvern:
heh the NHC TC Guidance hardly has a tropical storm in 02ATL future

Current: 25 knots (Low Pressure Area)
12 HRS: 30 knots (Tropical Depression)
24 HRS: 30 knots (Tropical Depression)
48 HRS: 35 knots (Tropical Storm)
72 HRS: 40 knots (Tropical Storm)


Is that based on SHIPS?
Member Since: Posts: Comments:
Good Morning!

Knew I should of fooled with the storm shutters...That usually stops this stuff from happening.

Thanks folks for staying up late. Always checking what you have to report.

I guess TD 2 is now here.

South Florida Water Management District Model Images


Member Since: Posts: Comments:
2835. HadesGodWyvern (Mod)
heh the NHC TC Guidance hardly has a tropical storm in 02ATL future

Current: 25 knots (Low Pressure Area)
12 HRS: 30 knots (Tropical Depression)
24 HRS: 30 knots (Tropical Depression)
48 HRS: 35 knots (Tropical Storm)
72 HRS: 40 knots (Tropical Storm)
Member Since: Posts: Comments:
2834. IKE
Good morning to all.

Yeah, the ECMWF is the best model I've seen in the Atlantic in 2009.
Member Since: Posts: Comments:
Quoting IKE:
ECMWF is really on board with the system behind TD2.


Godd morning to you, Ike

I usually stay out of the fray on the main blog as it just gets ridiculous! Beenreading along and noted that you have been bullish on the ECMWF this year. I agree with you and think that we will have to be vigilant concerning this next system.

It seems, at least according to the models, that TD2 is just plowing out the SAL for the next one, just have to wait and see.
Member Since: Posts: Comments:
2832. HadesGodWyvern (Mod)
Claudette, yup the next storm name is Maka
Member Since: Posts: Comments:
Morning HadesGodWyvern,

What is the next name for TD 01C?

Maka?
Member Since: Posts: Comments:
2830. Brallan
We got TD2 :D
Member Since: Posts: Comments:
2829. HadesGodWyvern (Mod)
Japan Meteorological Agency

Tropical Disturbance Summary (0600z 11AUG)
=========================================

At 15:00 PM JST, Tropical Depression, Former Morakot (998 hPa) located at 33.0N 121.0E has 10 minute sustained winds of 25 knots with gusts of 40 knots. The depression is reported as moving northeast of 10 knots
Member Since: Posts: Comments:


TD2
Member Since: Posts: Comments:
2827. HadesGodWyvern (Mod)
Central Pacific Hurricane Center
Tropical Cyclone Advisory #31
TROPICAL CYCLONE FELICIA (EP082009)
9:00 AM UTC August 11 2009
====================================

At 6:00 AM UTC, Tropical Storm Felicia (1007 hPa) located at 20.9N 153.0W or 140 NM east-northeast of of Hilo, Hawaii has sustained winds of 35 knots with gusts of 45 knots. The cyclone is reported as moving west at 9 knots.

Gale-force Winds
===============
120 NM from the center

Tropical Cyclone Watches
=======================
A Tropical Storm Watch remains in effect for Oahu and all of Maui county, which includes the islands of Maui, Kahoolawe, Lanai, and Molokai

Forecast and Intensity
======================
12 HRS: 21.0N 154.5W - 30 knots (Tropical Depression)
24 HRS: 21.1N 156.4W - 30 knots (Tropical Depression)
48 HRS: 21.5N 160.2W - 25 knots (Low Pressure Area)
Member Since: Posts: Comments:
Advisories for 8am then, I'd guess as 5am has just passed. Unless they feel like putting out one before.
Member Since: Posts: Comments:
2825. HadesGodWyvern (Mod)
National Hurricane Center
Tropical Cyclone Advisory #7
TROPICAL DEPRESSION EP092009
9:00 AM UTC August 11 2009
====================================

At 6:00 AM UTC, Tropical Depression Nine-E (1006 hPa) located at 15.1N 126.4W or 1050 NM west-southwest of the southern tip of Baja California Peninsula has sustained winds of 30 knots with gusts of 40 knots. The depression is reported as moving west at 10 knots.

Forecast and Intensity
======================
24 HRS: 15.1N 129.8W - 35 knots (Tropical Storm)
Member Since: Posts: Comments:
2824. HadesGodWyvern (Mod)
Central Pacific Hurricane Center
Tropical Cyclone Advisory #2
TROPICAL DEPRESSION CP012009
9:00 AM UTC August 11 2009
====================================

At 6:00 AM UTC, Tropical Depression One-C (1009 hPa) located at 13.8N 171.2W or 200 NM south-southwest of of Johnston Island has sustained winds of 30 knots with gusts of 40 knots. The depression is reported as moving west-northwest at 10 knots.

Forecast and Intensity
======================
12 HRS: 14.2N 172.7W - 35 knots (Tropical Storm)
Member Since: Posts: Comments:
Morning all, Ike,

I was just checking in. Barbados blob, now Caribbean blob not looking too bad this am, is it.

Its 5:30am here. Going to do a few things.

Have a good day.

Cheers.
Member Since: August 13, 2007 Posts: 0 Comments: 488
I can say i was one of the few here to see this :)
Member Since: August 29, 2006 Posts: 22 Comments: 1352
We have TD2!
Member Since: August 29, 2006 Posts: 22 Comments: 1352
And morning to all who are awake at this time.

Usually no-one here around this time (unless there is a storm)... downside to being five hours ahead.
Member Since: Posts: Comments:
Quoting nrtiwlnvragn:
invest_RENUMBER_al992009_al022009.ren

TD02


Yes its renumbered to TD02

Member Since: Posts: Comments:
2818. IKE
ECMWF is really on board with the system behind TD2.
Member Since: Posts: Comments:
Morning all -
I see that the models are still looking at the wave behind 99l in a big way. The ECMWF agrees with the GFS that there will be a BIG storm near the northern leewards around the 21st. Here is the web page, I will not post a link as I know there have been problems with viruses popping up in here....

http://www.ecmwf.int/products/forecasts/d/charts/medium/deterministic/msl_uv850_z500!Wind%20850%20a nd%20mslp!240!North%20America!pop!od!oper!public_plots!2009081100!!/
Member Since: Posts: Comments:
Hah. That's what you call cursing it...

Member Since: Posts: Comments:
Fancy seeing you here this late. O_O

A welcome sight, though. :D

I pull rather frequent all nighters, actually. Benefit of having no more school (until I find a college, that is). :P


Yeah i dont start the fall semester till the 24th so i'm cool we about to get some weather rolling through Monore in an hour or so so i'm up for that also...plus after all this time i want to be here when they classify this thing
Member Since: August 29, 2006 Posts: 22 Comments: 1352
2814. IKE
Quoting Cotillion:
Might go up to red at 8am, and then TD later... maybe looking for more consistency. Guess we'll see, but I don't think there's any rush for them to do it.

As it's moved from the CV islands, it won't find any land for some hundreds of miles.


oops! There it is!
Member Since: Posts: Comments:
invest_RENUMBER_al992009_al022009.ren

TD02
Member Since: Posts: Comments:
Might go up to red at 8am, and then TD later... maybe looking for more consistency. Guess we'll see, but I don't think there's any rush for them to do it.

As it's moved from the CV islands, it won't find any land for some hundreds of miles.
Member Since: Posts: Comments:
Quoting louisianaboy444:
I think the NHC is reasonably waiting to see if convection persists with 99L before designating it a tropical cyclone. I know I would.

Yeah i would have to agree i'm pulling an allnighter anyway...haven't had one in awhile lol


Fancy seeing you here this late. O_O

A welcome sight, though. :D

I pull rather frequent all nighters, actually. Benefit of having no more school (until I find a college, that is). :P
Member Since: Posts: Comments:
I think the NHC is reasonably waiting to see if convection persists with 99L before designating it a tropical cyclone. I know I would.

Yeah i would have to agree i'm pulling an allnighter anyway...haven't had one in awhile lol
Member Since: August 29, 2006 Posts: 22 Comments: 1352
I think the NHC is reasonably waiting to see if convection persists with 99L before designating it a tropical cyclone. I know I would.
Member Since: Posts: Comments:
Just one question,
Whats the name for the TD-1C "MAKA"?
Member Since: Posts: Comments:
Quoting hurricane23:


Yes...i expect TD classification later this morning.



95% next report still an invest.
Member Since: Posts: Comments:
Quoting Drakoen:
11/0545 UTC 14.4N 27.7W T2.0/2.0 99L -- Atlantic

Depression?


Yes...i expect TD classification later this morning.

Member Since: Posts: Comments:
Nobody has posted the second TCFA of 99L?
SUBJ/TROPICAL CYCLONE FORMATION ALERT 110600Z AUG 09//
WTNT01 KNGU 110600
REF/A/RMG/NAVLANTMETOCCEN NORFOLK VA/100600Z AUG 09//
AMPN/REF IS TROPICAL CYCLONE FORMATION ALERT (WTNT01 KNGU 110600)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
100 NM EITHER SIDE OF A LINE FROM 14.6N 26.9W TO 14.4N 33.0W
WITHIN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY
ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME.
WINDS IN THE AREA ARE ESTIMATED TO BE 15 TO 20 KNOTS. METSAT IM-
AGERY AT 110600Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 16.4N 26.9W. THE SYSTEM IS MOVING WESTWARD AT 15 KNOTS.
2. REMARKS:
THIS SUPERSEDES REF A.
FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
100 NM ON EITHER SIDE OF A LINE FROM 14.6 N 26.9 W TO 14.4 N 33.0
W WITHIN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTI-
FY ISSUANCE OF A NUMBERED TROPICAL CYCLONE WARNING AT THIS TIME.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED
BY 120600Z.
//

Everyone visit the Weather Chat. I'll be there, Bye!
Member Since: Posts: Comments:
Three?! ok... now the guys at the control pannel are just getting bored...
Member Since: Posts: Comments:
Yes 61w, very hot water, nice vortice, good convergence an divergence. Just some shear in the north. But good conditions to develop.

Member Since: Posts: Comments:
Hmmmm. The 00z Nogaps shoots what looks like 99L through the Yucatan channel on the 18th. Ten on the CMC it showed this low on the 18th. And notice the other 2 out to sea. Could it change? Probably will. :)

img src="cmc" alt="" />
Member Since: Posts: Comments:
Quoting jasoniscoolman10:
do you think this will be a tropical D at 5am i do not think so..


I dont think so.
I more worry about wave at 61W could develop in 24-48hrs.
Member Since: Posts: Comments:
What about 61W?

Member Since: Posts: Comments:
Quoting Drakoen:
11/0545 UTC 14.4N 27.7W T2.0/2.0 99L -- Atlantic

Depression?


Not according to what the models ran on but yea, we pretty much have TD 2. Wonder what the NHC will say at 8 AM.
Member Since: Posts: Comments:
Quoting Drakoen:
11/0545 UTC 14.4N 27.7W T2.0/2.0 99L -- Atlantic

Depression?


Sure looks like it. With those numbers, no way they don't do it at 5AM. We have our depression.
Member Since: Posts: Comments:
Cameron, La

Conditions at CAPL1 as of
(2:06 am CDT)
0706 GMT on 08/11/2009:

Wind Direction (WDIR): SSW ( 210 deg true )
Wind Speed (WSPD): 5.1 kts
Wind Gust (GST): 6.0 kts
Atmospheric Pressure (PRES): 30.07 in
Air Temperature (ATMP): 85.3 °F
Water Temperature (WTMP): 88.7 °F

Sabine Pass, Tx

Air Temperature (ATMP): 82.6 °F
Water Temperature (WTMP): 92.1 °F

Rollover Pass, Tx

Water Temperature (WTMP): 87.1 °

From a few that are still reporting. It's toasty in the NW Gulf. I would hate to see anything get under the right conditions anywhere in the Gulf.
Member Since: Posts: Comments:
Looks that way but since it is not bothering anyone right now they can afford to sit on it and wait 8-12 more hours just to be sure.
Member Since: Posts: Comments:
Quoting jasoniscoolman10:
models are crazy again at 2am..who know where this tropical low is going in the next two days..right now i think it will keep moving west right now.


You said we dont know, 2 days ago all models pull the wave WNW, and only move (2ºN and 7ºW).
My opinion is more west more possible to land in East Coast.
Member Since: Posts: Comments:
2790. Drakoen
11/0545 UTC 14.4N 27.7W T2.0/2.0 99L -- Atlantic

Depression?
Member Since: October 28, 2006 Posts: 57 Comments: 30833
Quoting azimut:
TD at 8am


Just to help you out there.
NHC would release TD status at 5am or 11am
the 8am is for their potential activity.
Member Since: Posts: Comments:

Viewing: 2839 - 2789

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 | 66Blog 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

Light Rain
42 °F
Light Rain Mist

JeffMasters's Recent Photos

Lake Effort Snow Shower Over Windsor, Ontario
Sunset on Dunham Lake
Pictured Rocks Sunset
Sunset on Lake Huron