Bonnie Advisories

[kevin]

Don't worry Josephine-o! I am in favor of bold statements, as opposed to statements that say nothing and declare nothing.

[Stormsfury]

Because its such a compact system, there are going to be MAJOR fluctuations in it's intensity.

Bingo ...

The shear over this system isn't necessarily strong, and the environment itself is weakly forced, so dynamical effects aren't going to play a huge role in sustaining convection ... Bonnie has been (up to this point) doing a decent job of that ...

We should see a gradual shift in the upper winds and the mean steering flow, and here within the next day should see the upper level winds shift towards the W and eventually SW ...

Two things to look for ...

Temporary healthy conditions for a short time as the upper level winds shift around allowing for a very small s/w ridge to pass aloft over Bonnie ... second, Bonnie will be passing over a warm eddy in the GOM where SST's are running 29ºC-30ºC, along with SST depths of 26ºC are greater than 100M ...

Don't be surprised to see a back and forth with max sustained winds should we get these occasional bursts of convection ...

SF

[kevin]

Josephine, I think at most tropical storm watches down to Cedar Key. At most Alachua county feels the southern portion of this storm, and that's an exageration since she's so compact.

[Brent]

Tropical Storm Bonnie Advisory Number 11

Statement as of 4:00 PM CDT on August 10, 2004

...Bonnie now moving slowly northward...

watches will likely be required later tonight for portions of the
northeastern Gulf of Mexico coastal areas.

At 4 PM CDT...2100z...the center of Tropical Storm Bonnie was
located near latitude 24.7 north...longitude 90.5 west or about
315 miles south-southwest of the mouth of the Mississippi River.

Bonnie is moving toward the north near 6 mph and this general
motion is forecast to continue tonight...with a gradual turn to
the northeast expected on Wednesday.

Maximum sustained winds are near 50 mph... 85 km/hr...with higher
gusts. While Bonnie has weakened slightly during the past few
hours...conditions appear favorable for some strengthening to occur
during the next 24 hours.

Bonnie remains a very small tropical storm. Tropical storm force
winds extend outward up to 45 miles from the center.

The estimated minimum central pressure is 1004 mb...29.65 inches.

Repeating the 4 PM CDT position...24.7 N... 90.5 W. Movement
toward...north near 6 mph. Maximum sustained
winds... 50 mph. Minimum central pressure...1004 mb.

For storm information specific to your area...please monitor
products issued by your local weather office.

The next advisory will be issued by the National Hurricane Center
at 10 PM CDT.

Forecaster Stewart

[Thunder44]

Pressure on Bonnie went down 1mb

URNT12 KNHC 102026
VORTEX DATA MESSAGE
A. 10/2026Z
B. 24 DEG 35 MIN N
90 DEG 34 MIN W
C. 850 MB 1455 M
D. 25 KT
E. 241 DEG 17 NM
F. 324 DEG 34 KT
G. 246 DEG 014 NM
H. 1003 MB
I. 18 C/ 1543 M
J. 24 C/ 1535 M
K. 17 C/ NA
L. NA
M. NA
N. 1345/8
O. 0.1/2 NM
P. AF977 0502A BONNIE OB 14
MAX FL WIND 43 KT SE QUAD 1842Z.

[Brent]

Tropical Storm Charley Advisory Number 6

Statement as of 5:00 PM AST on August 10, 2004

...Charley continues moving rapidly west-northwestward over the
Caribbean...tropical storm warnings issued...

At 5 PM AST...2100z...the government of Haiti has issued a Tropical
Storm Warning for the entire southwest peninsula of Haiti from the
Dominican Republic border westward including Port-au-Prince.

At 5 PM AST...2100z...the government of Jamaica has issued a
Tropical Storm Warning for Jamaica.

At 5 PM AST...2100z...the government of the Cayman Islands has
issued a tropical storm watch for the Cayman Islands.

At 5 PM AST...2100z...the center of Tropical Storm Charley was
located near latitude 15.2 north... longitude 70.8 west or about
440 miles... 710 km...east-southeast of Kingston Jamaica.

Charley is moving toward the west-northwest near 26 mph
...43 km/hr...and this general motion is expected to continue for
the next 24 hours. On this track the center of the storm will be
nearing Jamaica tomorrow morning.

Maximum sustained winds are near 50 mph... 85 km/hr...with higher
gusts. Some strengthening is forecast during the next 24 hours.

Tropical storm force winds extend outward up to 105 miles
...165 km from the center.

An Air Force reserve unit hurricane hunter plane recently reported a
minimum central pressure of 999 mb...29.50 inches.

Rainfall totals of 2 to 4 inches are likely in association with
Charley.

Repeating the 5 PM AST position...15.2 N... 70.8 W. Movement
toward...west-northwest near 26 mph. Maximum sustained
winds... 50 mph. Minimum central pressure... 999 mb.

For storm information specific to your area...please monitor
products issued by your local weather office.

An intermediate advisory will be issued by the National
Hurricane Center at 8 PM AST followed by the next
complete advisory at 11 PM AST.

[Brent]

New NHC track has it making landfall near Cedar Key, Florida on Saturday, then on the GA/SC border Sunday.

[Brent]

Tropical Storm Charley Discussion Number 6

Statement as of 5:00 PM EDT on August 10, 2004

There has been a significant shift in our track guidance for Charley
this afternoon. It appears that the dynamical models are showing a
greater influence of the eastern United States trough than in
earlier runs...eroding more of the western periphery of the
subtropical ridge and allowing the tropical cyclone to curve
northward sooner than earlier anticipated. Based on this guidance
change...the official track forecast has been shifted substantially
to the right of the previous ones. This is a little west of the
dynamical model consensus and close to the latest NOGAPS run.
Also...since the forward speed has not slowed thus far...the NHC
forecast is faster than the previous one. Near the end of the
forecast period...if Charley follows the indicated track...the
speed may very well be too slow but there is considerable
uncertainty in just where this system will end up in 3-5 days.
If the guidance for the next package is similar...the official track
may have be shifted a little farther to the east.
On their first penetration into this storm...the hurricane hunters
reported a 999 mb central pressure. The aircraft has not yet
sampled all quadrants of the tropical cyclone...but based on this
pressure reading the winds have been increased a little. The
upper-level outflow looks strong and the shear is expected to
remain weak over the next few days. Therefore conditions appear to
be favorable for intensification. Deep convection is currently
rather weak...but this may very well be a diurnal fluctuation. The
official forecast shows continued strengthening but remains more
conservative than the SHIPS guidance.
Forecaster Pasch

forecast positions and Max winds

initial 10/2100z 15.2n 70.8w 45 kt
12hr VT 11/0600z 16.3n 74.0w 50 kt
24hr VT 11/1800z 17.7n 77.4w 55 kt
36hr VT 12/0600z 19.4n 80.0w 55 kt
48hr VT 12/1800z 21.0n 82.0w 65 kt
72hr VT 13/1800z 25.0n 83.5w 75 kt
96hr VT 14/1800z 29.0n 83.5w 85 kt
120hr VT 15/1800z 33.0n 81.5w 25 kt...inland

[caneman]

still forecast to be a hurricane, watches at 10pm likely

Tropical Storm Bonnie Discussion Number 11

Statement as of 5:00 PM EDT on August 10, 2004

reconnaissance and satellite data indicate Bonnie has maintained a
tight inner-core wind field...despite the recent weakening of the
central convection. Ship h3gq reported 40 kt southwesterly winds
about 40 nmi south of the center at 18z. Based on this report and a
recon reported pressure of 1004 mb...the initial intensity is only
being decreased to 45 kt.

The initial motion estimate is 005/05. The last two recon positions
indicate Bonnie has finally made the long expected turn to the
north through a break in the subtropical ridge. Subsequent
satellite data confirms this motion...and possibly even a slight
east of due north motion. This new motion is already to the right
of the NHC model guidance suite...so the official forecast track is
just an extension and update of the previous forecast track. Bonnie
should begin to accelerate significantly to the northeast in 24-30
hours and make landfall in the central portion of the Florida
Panhandle in about 42 hours.

As mentioned in the previous advisories...Bonnie is expected to
remain a small tropical cyclone throughout the period...which can
result in rapid intensity fluctuations. Bonnie may be going through
one of those temporary fluctuations now. The intensity forecast is
predicated on deep convection returning within the next 6 to 12
hours. Arguments for thunderstorms redeveloping over the center
later tonight or Wednesday is...the recent improvement in the outer
banding features noted in satellite imagery...Bonnie expected to
move into a weak or even no shear environment in 12-24 hours...very
warm sea-surface temperatures...and the usual nocturnal convective
maximum period. However...by 36 hours...southwesterly upper-level
shear is expected to begin increasing...which may cap the intensity
trend prior to landfall. The official intensity forecast is the
same as the previous intensity forecast and is a blend of the SHIPS
and GFDL model intensity forecasts.
Watches for portions of the northeastern Gulf of Mexico coastal
areas may be required later tonight.

Forecaster Stewart

forecast positions and Max winds

initial 10/2100z 24.7n 90.5w 45 kt
12hr VT 11/0600z 25.5n 90.4w 55 kt
24hr VT 11/1800z 26.8n 89.5w 65 kt
36hr VT 12/0600z 28.5n 87.5w 70 kt
48hr VT 12/1800z 31.0n 84.0w 50 kt...inland
72hr VT 13/1800z 37.0n 76.5w 30 kt...extratropical
96hr VT 14/1800z 53.5n 68.5w 30 kt...extratropical
120hr VT 15/1800z...absorbed by frontal system

Anyone pick up on this statement? Sounds like the models could also shift right.

[Rainband]

Joy!

[tallywx]

So this sets up a very interesting scenario. With a Saturday landfall, it could very well be the case that a portion of the N. Florida coastline (say the Big Bend) could still be under a hurricane warning from Bonnie while simultaneously under a hurricane watch from Charley. Has this ever happened before?

[Brent]

Joy!

Help me out... where is Port Richey?

[ColdFront77]

I know, but won't answer.....

[cycloneye]

That is a significant shift of the official track now more to the east that will have big implications for many people.

[Thunder44]

It could come up the east side of Florida and up the east coast.

[Rainband]

Joy!

Help me out... where is Port Richey?

25 miles south of citrus county

[Brent]

Joy!

Help me out... where is Port Richey?

25 miles south of citrus county

YOUR IN THE EASTERN EYEWALL if the track verifies!!!!

[Rainband]

Joy!

Help me out... where is Port Richey?

25 miles south of citrus county

YOUR IN THE EASTERN EYEWALL if the track verifies!!!!

yep

[caneman]

Joy!

Help me out... where is Port Richey?

25 miles south of citrus county

Hey Rainband just south of you on the coast. Watching and wainting. MAy take up Steves advice and load up o some beer. Will definitley need a buzz if this thing decides to break bad on us

[Steve H.]

Don't jump the gun here!!!!!!!!! It's a situation where the runs could vary....like he said... wait until the set of models before reacting. That said, Charlie looks terrible right now, and if he keeps his forward speed, may not have sufficient time to strengthen signifiacntly.