Wilma steadily intensifying

By: Dr. Jeff Masters , 9:27 PM GMT on October 23, 2005

Wilma has entered a slow intensification phase the past three hours. The pressure has fallen from 963 mb to 959 mb, the eye has shrunk in diameter from 60 nm to 45 nm, and satellite imagery shows cooling cloud tops in the eyewall region--all signs of an ongoing intensification cycle. In response to this intensification cycle, the Hurricane Center has now upped their forecast of the maximum storm surge from 13 feet to 17 feet over southwest Florida. At the current rate of intensification, Wilma could become a Category 3 hurricane with 115 mph winds by midnight.

This intensification phase should slow down or reverse by midnight, since shear is now increasing over the storm. Shear is now about 15 knots, up from 10 knots this morning. The hurricane hunters noted that strong westerly winds aloft have pushed the top of the storm eastward, so that the area of calm in the eye at 10,000 feet is about ten miles east of the surface calm area. This stretching is also beginning to be evident on satellite images, with the shape of the hurricane appearing less circular. Assuming that the shear begins weakening the hurricane at midnight, only six or eight hours remain for the shear to weaken the hurricane before landfall at 6 am or 8 am Monday morning. This may not be enough time to weaken the storm much, so I am still anticipating a 105 mph Category 2 hurricane at landfall. By the time Wilma crosses the Florida Peninsula and arrives at the east coast of Florida, she should have top winds of about 85 mph.

The remainder of my discussion from noon today appears below, unchanged.

Assuming my forecast of a landfall near Marco, Florida as a Category 2 hurricane with 105 mph winds is a good one, we can expect a storm surge of 8 to 14 feet near that city and to the south. The Keys would see storm surge flooding of 5 to 8 feet. Fortunately, the area south of Marco is primarily uninhabited--the Everglades swamp. However, if Wilma comes ashore north of Naples--or further south near the Keys--storm surge flood damage in those areas could easily reach billions of dollars. Storm surge flooding should be only 2 - 4 feet on the east coast of Florida, where wind damage is the primary threat.

Figure 1. Storm surge map for southwest Florida.

Wilma's winds and rain
Wilma will be moving too fast to dump more than 5 - 10 inches of rain. The rain will be concentrated on the north side of the hurricane, since there will be a cold front there that will trigger more condensation. Areas to the north of the eye's passage will see winds a full Category--25 to 30 mph--lower than those on the south. This is because the storm's high rate of forward motion, near 25 - 30 mph, will add to the windspeeds seen on the south side of the Wilma's counterclockwise rotation, and subtract on the north side. Since the storm will be moving so fast, the duration of hurricane force winds will be just a few hours.

After Florida, then what?
After crossing Florida, Wilma should bring 50 - 60 mph winds to the northern Bahama Islands, but not hurricane force winds. Wilma should pass close enough to North Carolina's Outer Banks to bring 40 mph winds there and up to an inch of rain. It now appears that Wilma will bring 40 mph winds and 1 - 3 inches of rain to southeast Massachusetts, along with 20 foot waves. Boston, which has already had its fourth wettest October ever with 7.52 inches of rain, may break its October record. Nova Scotia will probably bear the brunt of Wilma's fury, receiving a direct hit by the center, along with 45 - 55 mph winds and rains of 3 - 5 inches.

Tropical Storm Alpha, the record-breaking 22nd tropical storm of this unbelievable hurricane season, has come ashore over Haiti and the Dominican Republic. Heavy rains of up to 12 inches could cause heavy loss of life in Haiti, where 98% deforestation rates have left the island highly vulnerable to flooding from even ordinary fast-moving tropical storms like Alpha. In the event a major flood disaster does ensue, dictating the retirement of Alpha's name, there are no contingency plans on how to replace Alpha's name on the list. Alpha is moving fast enough that I am hopeful a major flooding disaster will be averted in Haiti, though.

The 10,000 foot high mountains of Hispanolia have seriously disrupted the circulation of Alpha, making it questionable how much will remain of the storm to threaten the Turks and Caicos Islands. In any event, Alpha does not have long to live, as the huge circulation of Hurricane Wilma will overtake it by Tuesday and destroy the storm with high wind shear.

I'll be back with an update in the morning, or later tonight if events warrant.

Jeff Masters

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213. dcw
3:56 AM GMT on October 24, 2005
Cool storm. I'm pulling an all-nighter, this is exciting.
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212. IceSlater
11:55 PM EDT on October 23, 2005
Guys, the radar speed is NOT winds.. it's how fast the cell is moving...

Read the FAQ on the Radar:
Speed (knots) - Speed of the storm movement in knots.
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211. weatherwonderer
3:50 AM GMT on October 24, 2005
It looks like the E side is warming. Maybe it has seen its strongest point. This NOT a prediction just an observation.
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210. weatherwonderer
3:38 AM GMT on October 24, 2005
If you look at the IR loop you can see convection in the N part of the eye. This is either an attempt to close the eye off to as smaller eye or the eye is begining to degrade and the covection is filling in. Hard to tell atm. Would be interesting to see what the latest recon shows.
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209. weatherwonderer
3:33 AM GMT on October 24, 2005
I have been watching it. I have a hypothesis that it may be response to the approaching jet stream from the N. The eye may be trying to re-form to the south of the main eye.
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208. keeywester
3:33 AM GMT on October 24, 2005
the radar echo makes it look like an eye within the eye
207. keeywester
3:28 AM GMT on October 24, 2005
anyone see that weird vortex in the south portion of the eye in the KW radar? What's that all about?
206. FloridaBeachBum
3:28 AM GMT on October 24, 2005
nope .. tried to use an iframe and use my server to shrink the image down .. oh well
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205. FloridaBeachBum
3:26 AM GMT on October 24, 2005
lets see if this will work .. Key West Radar .. updated every 3 minutes....

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204. h0db
3:22 AM GMT on October 24, 2005
NHC made Wilma officially a CAT 3 Major Hurricane in their 23:00 EDT advisory.

WTNT34 KNHC 240241
11 PM EDT SUN OCT 23 2005


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203. stevego
3:21 AM GMT on October 24, 2005
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202. weatherwonderer
3:13 AM GMT on October 24, 2005
I'm watching the Ir and the radar and am trying to determine whether the eye is trying to close in or is degrading. It has made several attemps at getting smaller in the last couple of hours. It is defficult to tell if it is trying increase or decrease in intensity.
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201. dcw
3:07 AM GMT on October 24, 2005
We could embed that radar, but it'd make scrolling...how ya'll feel?
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200. FloridaBeachBum
3:03 AM GMT on October 24, 2005
here is a link to the Key West radar ... it is ana animated gif so let it load ... also the page will reload every 3 minutes
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199. ChrisPC24
2:59 AM GMT on October 24, 2005
People need to remember this is the storm that dropped 87 mb in 12 hours, and reached a record 882mb! It won't do that again, but it can intensify very fast, and it has.
198. nightbloomingjasmine
2:58 AM GMT on October 24, 2005
Yea I see it coming
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197. keeywester
2:57 AM GMT on October 24, 2005
Naples get ready.....what we are feeling now is not too far away from you
196. nightbloomingjasmine
2:51 AM GMT on October 24, 2005
globalize, I'm in Naples
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195. keeywester
2:53 AM GMT on October 24, 2005
From my vantage point, about 1/2 of Key West appears to be without power.
194. dcw
2:51 AM GMT on October 24, 2005
Wow, is anyone watching TWC? They just showed footage of this massive waterspout off Key West.
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193. dcw
2:44 AM GMT on October 24, 2005
The Base Radial Velocity from the Key West Radar. Hit the advanced radar options, then Base Radial Velocity .50.

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192. keeywester
2:42 AM GMT on October 24, 2005
Hello from the north side of Key West.....It's really cranking outside right now.....unbelievable winds in the last few minutes
191. Jeremey
10:42 PM EDT on October 23, 2005
NBC 2 in Ft. Myers has it as a 115mph Cat 3.
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190. dcw
2:44 AM GMT on October 24, 2005
...Wilma strengthens into a major category 3 hurricane...
...Tropical storm-force winds lashing the lower Florida Keys
and western Cuba...

a Hurricane Warning remains in effect for all of the Florida
Keys... including the Dry Tortugas and Florida Bay...along the
Florida West Coast from Longboat Key southward... and along the
Florida East Coast from Titusville southward... including Lake

At 11 PM EDT...0300z... the Tropical Storm Warning along the Florida
East Coast has been extended northward to St. Augustine. A Tropical
Storm Warning is now in effect along the Florida West Coast north
of Longboat Key to Steinhatchee river...and along the Florida East
Coast north of Titusville to St. Augustine.

A tropical storm watch is now in effect along the northeast coast of
Florida from north of St. Augustine to Fernandina Beach.

A Hurricane Warning remains in effect for the Cuban provinces of
Ciudad de la Habana...la Habana...and Pinar del Rio. A Tropical
Storm Warning is in effect for the Isle of Youth. A Hurricane
Watch remains in effect for the province of Matanzas. These warnings
and watches will likely be discontinued Monday morning.

A Hurricane Warning remains in effect for the northwestern
Bahamas...including the Abacos...Andros Island...Berry Islands...
Bimini...Eleuthera...Grand Bahama Island...and New Providence.

For storm information specific to your area...including possible
inland watches and warnings...please monitor products issued
by your local weather office.

At 11 PM EDT...0300z...data from an Air Force Reserve hurricane
hunter aircraft... NOAA Doppler radars... and satellite images
indicate the center of the large eye of major Hurricane Wilma was
located near latitude 24.4 north... longitude 83.7 west or about
120 miles... 195 km... west of Key West Florida and about 170
miles... 275 km...southwest of Naples Florida.

Wilma is moving toward the northeast near 18 mph...30 km/hr. A
continued northeastward motion... with a gradual increase in forward
speed... is expected tonight and Monday. On this track...the center
of Wilma is forecast to make landfall along the southwestern coast
of the Florida Peninsula early Monday morning. However... Wilma is
a large hurricane and tropical storm force winds will reach the
Florida Peninsula well before the eye makes landfall. The eastern
portion of the eyewall... accompanied by the strongest winds...
will reach the southwestern coast of Florida about 2 hours before
the center of the large eye makes landfall.

Maximum sustained winds are near 115 mph...185 km/hr...with higher
gusts. Wilma is a category three hurricane on the Saffir-Simpson
scale. Little change in strength is expected until landfall occurs
...And Wilma will likely make landfall as a category 3 hurricane.
Some slow weakening is forecast as Wilma crosses the southern
Florida Peninsula... but the hurricane is forecast to still be a
significant category two hurricane by the time the center reaches
the Florida East Coast early Monday afternoon.

Hurricane force winds extend outward up to 85 miles...140 km...
from the center...and tropical storm force winds extend outward up
to 230 miles...370 km. Sustained tropical storm-force winds are
occurring over the Yucatan Channel... western Cuba... and the lower
and middle Florida Keys. These winds should reach the southwestern
Florida coast by midnight... with hurricane-force winds reaching
the Lower Keys and southwestern Florida coast before sunrise.

The minimum central pressure recently reported by an Air Force
Reserve unit hurricane hunter aircraft was 958 mb...28.29 inches.

Storm surge flooding of 9 to 17 ft above normal tide levels is
possible along the southwest Florida coast near and to the
south of where the center of Wilma makes landfall. Storm surge
flooding of 5 to 8 ft above normal is possible in the Florida Keys
and Florida Bay... as well as in Lake Okeechobee. Storm surge
flooding of 2 to 4 feet is possible along the extreme southeastern
coast of Florida.

Wilma may produce additional rainfall accumulations of 5 to 10
inches through Monday across portions of western Cuba. Rainfall
across southern Florida and portions of central Florida...
including the Florida Keys... through Monday afternoon is expected
to be 4 to 8 inches... with isolated maximum amounts of 12 inches
possible. Rainfall totals of 2 to 4 inches will be possible over
portions of the northwest Bahamas.

Large swells generated by Wilma will continue to affect portions of
the northeastern Gulf Coast from the Florida Keys northward tonight
and early Monday.

The tornado threat across the central and southern Florida Peninsula
... And the Florida Keys... has increased significantly. Scattered
tornadoes will be possible in these areas tonight through Monday

Repeating the 11 PM EDT position...24.4 N... 83.7 W. Movement
toward...northeast near 18 mph. Maximum sustained
winds...115 mph. Minimum central pressure... 958 mb.

Intermediate advisories will be issued by the National
Hurricane Center at 1 am EDT and 3 am EDT followed
by the next complete advisory at 5 am EDT.

Forecaster Stewart

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189. theway
2:43 AM GMT on October 24, 2005
Where are you getting those numbers from?
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188. dcw
2:39 AM GMT on October 24, 2005
That 181 wasn't a gust! Unless gusts occur at 5k and 15k feet simultaneously? And hold for 5 minutes? Still showing 180+ at 5k and a crazy 200+KTS at 15000! Can a storm of this size even DO that?
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187. CrazyC83
2:34 AM GMT on October 24, 2005
Looking at that recording, I think they'll set it at 125 mph.
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186. dcw
2:32 AM GMT on October 24, 2005
By the way, look at Base Radial Velocity for winds, the tracks are how fast individual cells are moving.
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185. theway
2:29 AM GMT on October 24, 2005
URNT12 KNHC 240135
A. 24/01:12:40Z
B. 24 deg 15 min N
084 deg 08 min W
C. 700 mb 2732 m
D. NA kt
E. NA deg nm
F. 142 deg 114 kt
G. 039 deg 027 nm
H. 958 mb
I. 8 C/ 3053 m
J. 14 C/ 3047 m
K. 14 C/ NA
M. CO45-60
N. 12345/ 7
O. 0.02 / 3 nm
P. AF305 2424A WILMA OB 13
MAX FL WIND 114 KT NE QUAD 01:04:30 Z
MAX FL TEMP 16 C, 225 / 24NM
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184. dcw
2:28 AM GMT on October 24, 2005


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183. dcw
2:24 AM GMT on October 24, 2005
Please remember all, the doppler velocities are at an angle. To figure out true elevation of the echoes:

tan (angle)*distance from radar station=elevation

For example, the eyewall is a a 5000ft elevation from the Key West Radar (tan .5 * 124nm = 1.small nm high, 1nm=5280ft/1.15=4xxxft, 1.small * 4xxx ~ 5000). A 5000 foot elevation wind sig should be multiplied by .9 for ground use, so 123kt sig on Key West * .9 * 1.15 (kts to mph) gives 125mph surface.
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182. CrazyC83
2:25 AM GMT on October 24, 2005
Definitely. While I wonder if the 119 and 114 kt recordings are real or a fluke, I'd still put the intensity at least at 120 mph (105 kt) right now (Category 3)...
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181. weatherwonderer
2:19 AM GMT on October 24, 2005
Crazy, I have to agree, these storms in the gulf seem to want go crazy and defie logic. What ever it is...this thing is intensifing right now. The colder tops are building esp on the NW-W side.
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180. CrazyC83
2:17 AM GMT on October 24, 2005
Two cells now of Category 4 intensity
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179. LpAngelRob
9:15 PM CDT on October 23, 2005
Colder cloud tops are indicative of more intense convection taking place in the hurricane, not "it's less like a hurricane." Not sure if that was misinformed or a troll...
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178. CrazyC83
2:17 AM GMT on October 24, 2005
Knowing what happened with Charley, if I lived there, I would have prepared for a Category 4 hurricane...
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177. weatherwonderer
2:13 AM GMT on October 24, 2005
Radar presentation is showing the eye trying to shrink and the IR satellite is doing the same. Don't know how much it will intensify but I hope everyone that decided to stay listened to the NHC, i.e. prepare for a cat. 3 'cane. I wish the best for those that stayed. There is still time for the storm to weaken (as the jet stream sags South, or to intensify, which seems to be the norm this year for the gulf).
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176. globalize
2:12 AM GMT on October 24, 2005
nightblooming...where are you? It appears it won't intensify much more. The last few radar loops show it leveling off in intensity. It's strange that it has strengthened at all, considering the influences which should be weakening it. But who knows?
Member Since: August 30, 2005 Posts: 0 Comments: 1150
175. CrazyC83
2:14 AM GMT on October 24, 2005
That's what I am wondering - I'd say this is a 120 mph storm at least now...I wouldn't be surprised if it is a Category 4 at landfall now...
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174. CrazyC83
2:10 AM GMT on October 24, 2005
New cell approaching the lower Keys - 104 knots (120 mph)
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173. stevego
2:11 AM GMT on October 24, 2005
Hello to all this thing looks like it's intensifying pretty quick, is everyone underestimating this?
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172. CrazyC83
2:07 AM GMT on October 24, 2005
This thing is getting better organized looking at the radar...
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171. scribblin
2:08 AM GMT on October 24, 2005
Night all, for now. Got to get some rest before this thing really gets interesting.
170. globalize
2:05 AM GMT on October 24, 2005
keeywester- hello, and hang on bud. My oldest sis lives in Cudjoe Key (Summerland). She wanted to stay, but she's in Vero for the night. Glad you're riding it out.
Member Since: August 30, 2005 Posts: 0 Comments: 1150
169. CrazyC83
2:05 AM GMT on October 24, 2005
Key West is where you are? Looking at the radar, you have a clearing for the next hour or so, then comes the outer eyewall...
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168. nightbloomingjasmine
1:59 AM GMT on October 24, 2005
OK This thing can't really get any stronger can it???? God I hope not Looks like we'll be in the bathroom with all the animals in the morning.
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167. mybahamas
9:59 PM EDT on October 23, 2005
Allo Jimster .. it arrived to late to put up ... too windy for the 22-foot ladder :(
I have secured two rooms as "safe" in case anything happens, though, with shutters I built when Rita passed through.
I wish the best to all dealing with Rita :)
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166. keeywester
1:57 AM GMT on October 24, 2005
Lots of transformers exploding here across the water at the Navy property....huge green flashes! So far I still have power here....it's really picking up.
165. globalize
1:54 AM GMT on October 24, 2005
windnwaves aka 8888899...no, the colder the cloud tops, the more violent the storm.
Member Since: August 30, 2005 Posts: 0 Comments: 1150
164. MisterJimster
9:48 PM EDT on October 23, 2005
Did you ever get your plywood mybahamas? Hope so and hope you're doing okay.
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163. MisterJimster
9:45 PM EDT on October 23, 2005
What do you mean windnwaves?
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Dr. Masters co-founded wunderground in 1995. He flew with the NOAA Hurricane Hunters from 1986-1990. Co-blogging with him: Bob Henson, @bhensonweather

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