Dr. Jeff Masters' WunderBlog

143 kts is 165 mph!! 165mph is a Category 5 hurricane.

That was flight level, at the surface it would be around 150 mph.

if you compare the projected path of the center of circulation of the ull from the 0z gfs to the actual placement on 6z you will see that the ull has moved more south than the forecast. the gfs predicts that this feature will head rapidly west over the next 48 hours then on into texas. the speed and path of this feature is crucial and by no means totally in the bag.

are the hurricane hunters investigating dean now

Posted By: Bobbyweather at 7:00 AM CDT on August 18, 2007.
143 kts is 165 mph!! 165mph is a Category 5 hurricane.


That's flight-level...I think you deduct 10%....that puts it between 145-150 mph at the surface.

143 kts is 165 mph!! 165mph is a Category 5 hurricane.

Surface winds assume 90% flight winds.



165/90% = 148 so Cat 4 150MPH justified for Surface.

00Z is the 2am. The key is going to be how far north Dean gets passing Jamaica....lastest GFDL is more south.

yes the hurricane hunters are in it now. remember though, dean appears to be undergoing an eye wall replacement cycle

Thank you IKE, corrected in my previous post.
I've already gotten some very nasty WUMails from some people this morning, people are getting very tense and that is understandable. I do not want to add to the confusion.

in the top ten strongest Atlantic storms, the 10th is Janet of 1955, with pressure of 914 mb.

I am starting to feel more and more confident that Dean will not come to the Northern GOM. Think I will check back again tomorrow since the models are in more agreement with one another. Although I know stronger storms can have a tendency to just move around where they want so it is hard not to watch and wait for suprises. Does everyone think LA, MS, AL and FL can relax?

JRRP,

Thank you. I was asking (without response) if I was really seeing what I was seeing.

Good Morning Gang,

On the last 3-4 frames of the IR..It seems to have moved a bit more to the north..My crude measurments are about 5 deg...

Does anyone else note this?

then what's the 145 next to the flight level?

Cenral Atlnatic Wave Update

A tropical wave is along 33W-34W south of 24N moving west near 16 knots. Recent PV analysis and the first visible image of the day shows this wave continues to exhibit inverted V curvature and clear cyclonic rotation in the surrounding mid-low level cloud field across the the Tropical Atlantic north of 15N. However this part of the wave axis is enveloped in very dry African Dust and thus convection remains absent.

Another interesting feature is QuikSCAT continues to show cyclonic curvature in the area of showers to the south of the ITCZ (purple line in the image below). None of these features are showing signs of organziation at the moment and is just something to watch.

by Weather456

Interesting, the 06Z 08/18 GFDL bends a little more north at first, then flattens out and ends up more south.

JRRP...what city are you in? My dad's in La Romana right now making sure our hotels are all locked down tight, and he called to say a band came in that was pretty strong. What about where you are?

143kt is significantly lower than last night's final pass, which measured 154kt.

recon up

11:50:30
15.40N 67.82W
Flight level winds From 137° (SE) at 143 kts (164.4 mph)
924.1 mb
surface wind 121 kts

BiloxiGirl

Does everyone think LA, MS, AL and FL can relax?

Nope... not yet.

Look at PR radar. If I were in Haiti and the DR, I would be worried.

143kt is significantly lower than last night's final pass, which measured 154kt.

They just got up there.

how close is that to the center

ok well the hurricane hunters are just now starting so it will be interesting to see what they find.

Nice turn to the NW

yes and look at the pressure. it is 924mb

JPV - so if all the models are converging much further south, what scenario would ever bring it up to say LA and MS?

920.4mb extrapolated by recon.

the eye is getting freaking tiny....def. see an ewrc coming up shortly...

924.1 mb - Getting stronger

Just the Hurricane is undergoing a EWRC

This thing will be a massive monster after this replacement cycle.

I think the NHC is going to have to shift the short term forecast north with Dean. If you look at the 5am and 8am advisories, you can tell that Dean has jogged north.

5am Link
8am Link

143kt was from the inner eyewall. Outer had definite wind maximum, but not nearly as strong as the inner yet.

Biloxigirl, We can relax when it makes landfall somewhere else....hopefully northern Mexico

Posted By: BiloxiGirl at 7:09 AM CDT on August 18, 2007.
JPV - so if all the models are converging much further south, what scenario would ever bring it up to say LA and MS?


Unless the high doesn't build in and there's very little reason to doubt it won't.

Biloxi, I'm in Florida and I'm so relieved that it's not coming this way. I think it's pretty much a given that we won't meet Dean.

There's something else out there, but I've just decided to ignore it for now.

Posted By: BiloxiGirl

JPV - so if all the models are converging much further south, what scenario would ever bring it up to say LA and MS?

5 day forecasts aren't very reliable.

And hurricanes can be VERY unpredictable.

Not saying that it will make a US landfall, but I think that it's way too early to call it, either way.

FLWeather
IN SANTO DOMINGO

where are you guys getting those measurements

VORTEX DATA MESSAGE AL042007
A. 18/11:51:20Z
B. 15 deg 23 min N
067 deg 52 min W
C. 700 mb 2437 m
D. 121 kt
E. 5 deg 008 nm
F. 137 deg 145 kt
G. 050 deg 008 nm
H. 926 mb
I. 11 C/ 3049 m
J. 23 C/ 3041 m
K. 11 C/ NA
L. CLOSED
M. C12
N. 12345/ 7
O. 0.02 / 2 nm
P. AF304 0604A DEAN OB 03
MAX FL WIND 145 KT NE QUAD 11:48:40 Z
SMALL HAIL INBOUND NE QUAD
RADAR PRESENTATION EXCELLENT

Hail in a hurricane?..??....??

Dean

Storms this big and strong can in a way create their own environment and can go where they want. No they don't blast through a giant high pressure system or anything like that, but they tend to have a few tricks up their sleeves sometimes.

Hail is rare..if at all common when they move ashore...but can be quite common when there over open water

Biloxigirl - If you look at Dr. Master's post you will see that the accuracy of the models drops off rapidly the further out you go in time. To make things worse, the land around the GOM makes a circle which means that even a small jog left or right can change the landfall location by 100 miles. Everyone needs to stay vigilant.

I see that Dean wobbled north and in the last few frames through 09:45Z is moving parallel and just north of the NHC track. I will henceforth remove my name from the list of wobblecasters and do my wobblewatching in private until I see a significant trend.

Hail was reported in a 1995 hurricane...cant remember the name..I think it was the "m" storm

JRRP, how are the people preparing for The Storm? I remember when I was down there for Georges no one did anything, many people didn't even know what was coming.

Never would have guessed hail in a hurricane. Never seen it myself, but I don't go out side during storms.

I think I am looking for an excuse to stop driving myself crazy monitoring this storm. I check on it frequently throughout the day and I think I am trying to talk myself into thinking that I really shouldn't worry about it. But it sounds like maybe we aren't to that point just yet.

Wow, I was away for much of yesterday evening and come back to a massive cat 4! Yikes.

This thing will be a massive monster after this replacement cycle.

What is the replacement cycle? This is a new term for me.

Hail happens, but it's quite rare in tropical systems. I have no idea what it means, though.

I'm very surprised not to see concentric eyewalls in that report.

Odd but I can see it happening. Massive updrafts bring up to the very to where satilights have recorded -66C