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: 589 - 539

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 BurnedAfterPosting:


that is from last night


No, it is not, read the time on the image.
Member Since: Posts: Comments:
how can i write a letter to admin?
Member Since: Posts: Comments:
Quoting louisianaboy444:
The AOL near the islands has alot of what it needs its about taking advantage of its environment


there is a web browser by the islands? LOL

I think you meant AOI, just messin with ya tho lol
Doesn't look like KOTG either
Member Since: Posts: Comments:
Any foul Language,whether implied or italicized will be given a Permanent Ban
Member Since: Posts: Comments:
Quoting WeatherStudent:


?

or shall i say JVF/ I been lingering/lurking around 7 yrs good grief, learn a thing or 2, watch and wait is the cue.
Member Since: Posts: Comments:
Quoting alaina1085:
Hurricanehanna

Was it you that posted earlier about the 70% chance of a hit from Louisiana to Alabama from some study? I cant remember what all you said because the new blog came up.


Nope - not me. And I hope it's wrong!
Member Since: Posts: Comments:
Quoting KEEPEROFTTHEGATE:


I AGREE ITS PATHETIC WE NEED TO DEVELOP A SERIOUS GAMEPLAN TO HALT THE IMPOSTOR BEFORE HE STEALS MULTIPLE IDENTITIES LIKE LAST YEAR. HE EVEN STOLE MINE TWICE.

Keeper of the gate has only one T you are the imposter too! KEEPEROFTTHEGATE
Member Since: Posts: Comments:
The AOL near the islands has alot of what it needs its about taking advantage of its environment
Member Since: Posts: Comments:
TROPICAL WAVE IS ALONG 58W S OF 18N MOVING W 10-15 KT. WAVE IS
LOCATED ALONG A MOISTURE MAXIMUM AS OBSERVED ON THE TOTAL
PRECIPITABLE WATER IMAGERY. A LOW LEVEL CYCLONIC CIRCULATION IN
THE LOW CLOUDS IS ALSO ALONG THE WAVE AXIS NEAR 13N.
SCATTERED
MODERATE TO ISOLATED STRONG CONVECTION IS OVER THE WINDWARD
ISLANDS FROM 12N-15N BETWEEN 57W-62W.

Member Since: October 28, 2006 Posts: 57 Comments: 29909
Quoting KYhomeboy:
Kman...you called it on the Barbados system!


Let's see how it fares for the next 12 hours. If the rate of development contiunes uninterrupted this will go to orange by midnight IMO
Member Since: Posts: Comments:
572. Skyepony (Mod)
That's up 2 mb since the last plane was out there.


Product: Air Force Vortex Message (URPN12 KNHC)
Transmitted: 10th day of the month at 17:48Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 309)
Storm Number & Year: 08E in 2009
Storm Name: Felicia (originating in the Northeast Pacific basin)
Mission Number: 8
Observation Number: 04
A. Time of Center Fix: 10th day of the month at 17:20:30Z
B. Center Fix Coordinates: 20°55'N 150°32'W (20.9167N 150.5333W) (View map)
B. Center Fix Location: 307 miles (494 km) to the ENE (74°) from Hilo, on the island of Hawaii, HI, USA.
C. Minimum Height at Standard Level: 1,479m (4,852ft) at 850mb
D. Estimated (by SFMR or visually) Maximum Surface Wind: 23kts (~ 26.5mph)
E. Location of the Estimated Maximum Surface Wind: 42 nautical miles (48 statute miles) to the SSW (206°) of center fix
F. Maximum Flight Level Wind Inbound: From 324° at 23kts (From the NW at ~ 26.5mph)
G. Location of Maximum Flight Level Wind Inbound: 67 nautical miles (77 statute miles) to the SW (214°) of center fix
H. Minimum Sea Level Pressure: 1007mb (29.74 inHg)
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 17°C (63°F) at a pressure alt. of 1,677m (5,502ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 19°C (66°F) at a pressure alt. of 1,676m (5,499ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 15°C (59°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, Pressure and Temperature
N. Fix Level: 850mb
O. Navigation Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 1.5 nautical miles
Remarks Section - Remarks That Were Decoded...
Maximum Flight Level Wind: 23kts (~ 26.5mph) in the southwest quadrant at 16:59:30Z
Maximum Flight Level Wind Outbound: 45kts (~ 51.8mph) in the northeast quadrant at 17:43:30Z
Remarks Section - Additional Remarks...
FLT LVL CTR ORIENTED N-S. SFC NOT VISIBLE DUE TO UNDERCAST
Member Since: Posts: Comments:
Quoting alaina1085:


Hes slightly obsessed...LOL.

Yeah, Stewie is my hero!
Member Since: Posts: Comments:
Quoting boltdwright:
According to QUIKSCAT, there is not yet a closed circulation on the disturbance near 54 west latitude.


that is from last night
Hurricanehanna

Was it you that posted earlier about the 70% chance of a hit from Louisiana to Alabama from some study? I cant remember what all you said because the new blog came up.
Member Since: Posts: Comments:
Quoting gator23:
Tropical Update ont he Weathe Channel "We will monitor this wave" They Suck.
What do you want them to do? Not monitor it?
Member Since: Posts: Comments:
550. GoodOleBudSir 2:05 PM EDT on August 10, 2009
Quoting WeatherStudent:


star what,everyoen agress with me, he's an imposter, grow up. anyways back to teh tropics


WS,
What language is that?


WS you need a drink or some pill.......calm down dude.....LOL.....
Member Since: September 2, 2007 Posts: 178 Comments: 20439
According to QUIKSCAT, there is not yet a closed circulation on the disturbance near 54 west latitude.
Member Since: Posts: Comments:
Quoting Patrap:
As of Now, the rules of the road,Jeff Masters Blog Rules and community Standards are being enforced 100 percent.

Avoid quoting post that are obvious fakes,monomania and other.


Patrap, sorry, I did not know was a fake thought just a joke, once I saw the markers, could'nt stop laughing.
Member Since: Posts: Comments:
the coc/lcc of the barbados low is just on the ne side of the island...winds primarily from the wnw and w...
Member Since: Posts: Comments:
Quoting hurricanehanna:

You must be a Family Guy fan! lol


Hes slightly obsessed...LOL.
Member Since: Posts: Comments:
00z

06z

12z
Member Since: Posts: Comments:
Quoting louisianaboy444:
We will have no idea where anything is going for at least 6 days so to keep us occupied ladies and gentleman Mr. Conway Twitty

Image and video hosting by TinyPic

You must be a Family Guy fan! lol
Member Since: Posts: Comments:
LMAO!
Member Since: Posts: Comments:
Quoting cchsvweatherman:


We can rest comfortably, however, that no one would steal your avatar.


I was about to put you on ignore, and I probably still will, but this is pretty funny...
Member Since: Posts: Comments:
Quoting WeatherStudent:


star what,everyoen agress with me, he's an imposter, grow up. anyways back to teh tropics


WS,
What language is that?
Member Since: Posts: Comments:
still trying to figure out why I had a 48 hour ban...??
Member Since: Posts: Comments:
We will have no idea where anything is going for at least 6 days so to keep us occupied ladies and gentleman Mr. Conway Twitty

Image and video hosting by TinyPic
Member Since: Posts: Comments:
As of Now, the rules of the road,Jeff Masters Blog Rules and community Standards are being enforced 100 percent.

Avoid quoting post that are obvious fakes,monomania and other.
Member Since: Posts: Comments:
Felicia appears nakid and exposed 300 miles East of the Hawaiian island chain. Will she make it into port? We turn now to our ever alert island crew. "Pass da poi, Brudda, da winds she going ta blow and the wave dai going to flow." Thanks for that timely advice. Now back to the crew searching madly for signs of ANA.
Member Since: Posts: Comments:
Quoting NEwxguy:
Well,I for one started making immediate preparations up here for the pending super Nor'easter headed our way,anyway here would be utterly reckless to not heed these warnings after seeing those detailed graphics


Even though I won't be suffering through the Barbados NorEaster, I'll be stockpiling beer pretty heavily for the event.
Member Since: Posts: Comments:
Quoting TexasWynd:
thx ignoring WS till he grows some chest hair
Ignore #9
Quoting cchsvweatherman:


I'm most certainly not a troll, and take offense to such a statement.

We can rest comfortably, however, that no one would steal your avatar.
ignore #10 and reported!
Member Since: Posts: Comments:
Quoting BurnedAfterPosting:


That can't be the REAL cchsweatherman. I noticed the extra "V" in the screen name.
Member Since: Posts: Comments:
I'll alert the medi...er um myself..
Member Since: Posts: Comments:
Member Since: Posts: Comments:
WeatherStudent. my lord; so much to learn.. and aint learning nothing
Member Since: Posts: Comments:
hi guys seem that we have two systems on the two
Member Since: Posts: Comments:

Viewing: 589 - 539

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

Mostly Cloudy
70 °F
Mostly Cloudy