Here’s what Dean looked like at midnight EDT:

Just making a brief pit stop at the hotel after my awesome Shuttle/ISS sighting (photos later), and wanted to post this satellite image of Hurricane Dean, now officially a Category Five:

Say a prayer for everyone in that monster’s path tonight. Yeah, it could have been worse, but it’s going to be very bad where it does hit.

Dr. Jeff Masters has more. I’m off to 2nd Avenue.

A special 8:35 pm Eastern update from the NHC:

DATA FROM THE AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT CURRENTLY
INVESTIGATING HURRICANE DEAN INDICATE THAT MAXIMUM SUSTAINED WINDS
HAVE INCREASED TO 160 MPH…MAKING DEAN A POTENTIALLY CATASTROPHIC
CATEGORY FIVE HURRICANE ON THE SAFFIR-SIMPSON HURRICANE SCALE.

At least we can stop saying that Dean is expected to reach Category 5 in the next 24 hours …

As of 8:00 PM, Dean’s maximum sustained winds are now at 155 mph, according to the National Hurricane Center. That puts him 1 mph short of Category 5. Minimum central pressure is 915 mb.

I know I said I’d be blogging Dean’s approach to the Yucatan tonight, but then it occurred to me: I have a free night in Nashville, courtesy of the great state of Tennessee. Is sitting in my room, watching The Weather Channel and surfing the Internet, really the best way to spend my time? I think not. I’m a weather nerd, but I’m not that much of a weather nerd. :) I’m in Nashville; I ought to go out and do something… Nashville-ish. So I’m going to head over to the Parthenon and try to get a photo of the Shuttle and ISS flying over it. Then I think I’ll sample a bit of Nashville’s legendary nightlife. Don’t worry, Becky: I won’t stay out too late, or drink too much. :) I have a seminar to attend in the morning, after all. But I could deal with a little bit of honky-tonk tonight!

Anyway, further updates on Dean will most likely be via cell phone, or by guestbloggers, at least till I get back to the hotel.

As I looked for some different views on Hurricane Dean, I saw Eric Berger’s post asking “Has Hurricane Dean been overhyped?” I think it is a very interesting question because I started to wonder that myself from all the news stories I have seen… One of the stories I saw made the comment about “Dean heading straight for Cancun!” Really? To me the forecast track looks considerably to the south of both Cancun and Cozumel. Also Eric, highlights in his post this concern from Texas Lt. Gov David Dewhurst because two models still bring Dean into the state. He points out that these two models, the CLP5 and the LBAR, do not have the track record and in fact the CLP5 is not really a model.

In my opinion, as I see all the stories, reports, watch cable news where CNN has the edge of the screen showing the recent NHC report on Dean and the satellite image there. The promos on FOX News on how they are “Your Official source on Hurricane Dean.” So I asked myself, What would the coverage be like if Dean was actually going to HIT the United States. If this is the standard set for all Hurricanes the rest of the season, it will definitely be interesting.

I also have to ask, does Dean want to be a Category 5? I mean how many days are we going to report, “Dean is forecasted to become a category 5 in the next 24 to 36 hours.” Like I mentioned on my Weather Blog, I understand why we all forecast Dean to reach Category 5 strength, all the conditions are favorable for category 5 strength. It just doesn’t seem like Dean wants to take advantage of it. I am still going to agree with the current forecast, I just won’t be surprised if it stays a category 4.

Over at Dr. Jeff Master’s blog, it looks like he too is watching the potential proto-Felix.

An area of disturbed weather associated with a tropical wave a few hundred miles northeast of the Lesser Antilles Islands, “Invest 92L”, has changed little in organization today. Wind shear is about 5-10 knots in this region, and an upper-level anticyclone has formed over 92L. This is a very favorable environment for intensification, should 92L start to get organized. The disturbance has the potential to develop into a tropical depression by Wednesday. It is moving west to west-northwest at 15-20 mph, and will be near the central Bahamas by Wednesday, and the east coast of Florida by Friday. It does not appear that any troughs strong enough to recurve 92L will swing by until Saturday at the earliest.

Brendan, hope your seminar is going well

A few minutes after I posted my last update, the recon plane sent a new report indicating flight-level winds of 174 mph. According to the standard 90% formula, that translates to 156 mph winds at the surface — literally the very minimum for Category 5 status. But the NHC has decided to continue classifying Dean as a 150 mph Cat. 4 for now. The discussion explains that they’re having trouble getting all the data from the recon plane, and meanwhile other available data suggests a slightly lower intensity:

COMMUNICATIONS PROBLEMS ARE PREVENTING THE RECEIPT OF MOST DATA FROM THE AIR FORCE RECONNAISSANCE AIRCRAFT THIS AFTERNOON…ALTHOUGH A [3:30 PM EDT] VORTEX FIX WAS RECEIVED. AT THAT TIME THE MINIMUM PRESSURE WAS 918 MB…WITH MAXIMUM FLIGHT-LEVEL WINDS OF 151 KT [174 MPH]. EARLIER IN THE FLIGHT…A PEAK SFMR [SURFACE] WIND OF [141 MPH] WAS OBSERVED. DVORAK CLASSIFICATIONS FROM TAFB AND SAB WERE [146 MPH] KT AT [2:00 PM EDT]. BASED ON THESE DATA…THE INITIAL INTENSITY IS HELD AT [150 MPH].

Okay, back to work! (These 15-minute breaks between seminar lectures are great for hurricane-blogging. :)

The most recent recon plane to investigate Dean found a pressure of 924 mb — down just 2 mb from the wee hours of this morning — and top flight-level winds of 161 mph, down from 167 mph this morning. (Multiply by 0.9 for the approximate top surface winds.) As a result, the NHC kept Dean at 150 mph as of the 2:00 PM advisory. So it appears this storm is in no huge hurry to begin rapidly intensifying, my earlier post notwithstanding.

That said, he’s looking better and better organized on the satellite loop, so I still think it’s only a matter of time before he achieves Cat. 5 status:

The next recon mission is set for 8:00 PM EDT. And my break is almost over. Back to the seminar…

From the NHC’s 11 am discussion,

THE NEXT RECONNAISSANCE FLIGHT WILL BE AT 18Z THIS AFTERNOON. IN THE MEANTIME… RECENT MICROWAVE DATA SHOW A SINGLE EYEWALL THAT HAS BECOME BETTER DEFINED WITH COLDER TOPS IN CONVENTIONAL SATELLITE IMAGERY OVER THE PAST COUPLE OF HOURS. THE ADVISORY INTENSITY WILL BE HELD AT 130 KT…BUT LATEST SATELLITE IMAGES INDICATE THAT DEAN IS APPROACHING CATEGORY FIVE STATUS…AND IT IS EXPECTED REACH THAT THRESHOLD LATER TODAY OVER THE DEEP WARM WATERS OF THE WESTERN CARIBBEAN.

The advisory gives a central pressure of 925 mb, sustained winds at 150 mph. Landfall on the Yucatan is expected very early Tuesday morning, but conditions will be deteriorating today as the storm approaches. Hurricane warnings are in effect in Mexico and Belize from Cancun south to the Belize/Guatamala border, and also on the west coast of the Yucatan from south of Progresso to Ciudad del Carmen.

FYI - I’m heading to Nashville in the morning for a two-day State of Tennessee law-clerk seminar thingy, so blogging will be extremely sporadic tomorrow and Tuesday, I’m afraid. The timing sucks, as tomorrow will probably be one of those exciting days for a weatherblogger, filled with amazing and terrifying images of a rapidly intensifying Category 5 hurricane… but what can ya do? Duty calls. At least I should be able to blog from my hotel room tomorrow night as Dean approaches the Yucatan. And I’ve again asked my hurricane guestbloggers to help fill in when I’m indisposed. (Speaking of which, thanks, Brian, for your help today!)

Anyway, Dean has now officially cleared the western tip of Jamaica. It never actually made landfall; according to the 11:00 PM discussion, the closest approach occurred when the center of the eye “came within about [23 miles] of Portland Point of the south-central coast.” Tomorrow, we’ll start to find out what kind of damage Dean did. Hopefully it wasn’t too severe, though I’m sure it wasn’t a cakewalk on the island, especially the south shore.

The downside of Dean’s eye failing to hit land is that it didn’t weaken over said land. So now the conditions are ripe for some potentially historic intensification tomorrow. That Dean will become a Category 5 hurricane tomorrow is, I think, almost a foregone conclusion, given the favorable atmospheric conditions, the lack of land interaction, and the extremely warm water:

The brown line is Dean’s approximate track so far; the black line is the approximate forecast track.

The heat potential isn’t quite as high as it would be if Dean were trekking a bit further north, but even so, it’s plenty warm enough to support rapid intensification; indeed, it’s significantly warmer than the water (between the two small black vertical lines near the lower right-hand corner of the map above) in which Dean exploded from a low-end Cat. 2 into a high-end Cat. 4 on Friday. And because of his failure to make landfall in Jamaica, Dean starts his trek into these bathtub-like Western Caribbean waters with a top wind speed of 145 mph and a minimum pressure of 925 millibars. So the question, I think, is not whether he’ll strengthen into a Cat. 5; the question is, how low can he go? Pressure-wise, that is. Gilbert, following a similar track 19 years ago, held the Atlantic-basin record (888 mb) until Wilma surpassed it in 2005 with a mark of 882 mb. Can Dean rival these numbers? I’m not predicting it, but I certainly don’t think it’s out of the question. He dropped 46 millibars in 24 hours on Friday, where the heat potential was, on paper, not even quite high enough to support rapid deepening. Another 46-millibar drop tomorrow, in these far more conducive waters, would break Wilma’s record by 3. I’m just sayin’.

Can anything hold Dean back? Maybe another eyewall replacement cycle… but you’d think that wouldn’t happen for a while, now that the lengthy cycle which continued throughout Dean’s approach and passage of Jamaica is finally over. We’ll see.

In any event, the good news is that Dean now appears to be headed for an area of the Yucatan Peninsula that’s much more sparsely populated than the Cancun/Cozumel area. Hopefully the people who do live along the targeted coast are taking the proper precautions and getting themselves out of harm’s way, because regardless of whether Dean approaches any meteorological records, the bottom line is that they are going to be hit very hard.

Anyway, here’s what the 11:00 PM discussion has to say about Dean’s track and intensity:

DEAN IS HEADING TOWARD 280 DEGREES [i.e., just north of due west] AT ABOUT [20 MPH] WITH STEERING PROVIDED BY A STRENGTHENING MID-LEVEL RIDGE OVER THE SOUTHEASTERN UNITED STATES. THE MODELS ALL AGREE THAT THE RIDGE WILL GET EVEN STRONGER AND MOVE A LITTLE WESTWARD WITH DEAN…MEANING THAT DEAN WILL PROBABLY MOVE IN A RATHER STRAIGHT LINE UNTIL FINAL LANDFALL IN MEXICO. OVERALL THE MODELS HAVE AGAIN EDGED A LITTLE SOUTHWARD…AND SO HAS THE OFFICIAL FORECAST. …

ALL OF THE OBJECTIVE GUIDANCE CALLS FOR STRENGTHENING IN THE NORTHWESTERN CARIBBEAN WHERE THE SHEAR WILL REMAIN WEAK AND THE OCEAN HEAT CONTENT VERY HIGH. THE OFFICIAL FORECAST FOLLOWS SUIT AND INDICATES THAT DEAN COULD REACH CATEGORY FIVE STATUS DURING THE NEXT DAY OR SO. THE HURRICANE WILL WEAKEN WHILE OVER YUCATAN IN PROPORTION TO JUST HOW LONG IT SPENDS OVER LAND. THE OPPORTUNITY FOR RESTRENGTHENING OVER THE SOUTHWESTERN GULF LIKEWISE DEPENDS ON THE EXACT TRACK…AND THAT WINDOW HAS BEEN SHORTENING WITH THE SOUTHWARD SHIFTS IN TRACK. ALTHOUGH NOT EXPLICITLY INDICATED IN THE NEW OFFICIAL FORECAST…IT IS STILL POSSIBLE THAT DEAN COULD RESTRENGTHEN AND AGAIN REACH MAJOR HURRICANE STATUS PRIOR TO FINAL LANDFALL ALONG THE COAST OF MAINLAND MEXICO.

P.S. In other tropical news, Brian Neudorff notes a tropical storm over Oklahoma — well, the remnants of Erin, anyway, looking mighty spiral-y! — and a potential proto-Felix.

UPDATE, 2:00 AM: Dean’s pressure went up a millibar, to 926… but its top wind speed is up too, to 150 mph.

UPDATE, 7:13 AM: Another eyewall replacement cycle already?? According to the 5am discussion, “OBSERVATIONS FROM THE LAST AIR FORCE HURRICANE HUNTER MISSION AGAIN INDICATED A CONCENTRIC EYEWALL STRUCTURE.”

Hurricane Dean’s eyewall may have stayed just offshore of the heavily populated areas, but don’t let that fool you: it’s been a very bad day in Jamaica, writes Dr. Jeff Masters:

It could have been much worse, but it is very bad for Jamaica. Hurricane Dean’s northern eyewall is just offshore the southern tip of Jamaica, bringing sustained Category 2 hurricane winds to southern Jamaica. A recent wind analysis prepared by NOAA’s Hurricane Research Division (Figure 1) at 3:30pm EDT today shows winds of Category 1 strength (>65 knots, or 74 mph) already affecting the east end of the island. By extrapolating this wind field over the island to the west-northwest, in anticipation of Dean’s track, it is apparent that perhaps 90% of the island will experience sustained winds of 74 mph or greater. At 4pm EDT, Kingston, on the southern side of the island, recorded sustained winds of 81 mph before the instrument failed. We can expect that the southern 1/3 of the island, including Kingston, will receive sustained winds of Category 2 strength–96 to 114 mph. Category 3 and higher winds will be confined to the southernmost 5% of the island, and it appears that the Category 4 winds will stay offshore. The portion of the island affected by the Category 3 winds is very sparsely populated.

Jamaica will suffer billions in damage from Dean. The high winds and rains of up to 20 inches will no doubt claim lives, although probably not as many as the 45 who died during Hurricane Gilbert of 1988. Gilbert cut straight across Jamaica as a Category 3 hurricane with 125-130 mph winds. Kingston measured sustained winds of 116 mph during Gilbert; I expect the top winds in Dean will be 10 mph slower than that.

UPDATE: Welcome, again, InstaPundit readers! Click here to read all my Dean-related posts.

…or has Hurricane Dean taken a perceptible wobble toward the northwest (as opposed to west or WNW) — that is to say, a wobble toward Jamaica — in the last two or three satellite frames? I know we’re not supposed to read too much into “wobbles,” but yikes, I do hope it starts wobbling back the other way…

UPDATE: Well, okay, not quite northwest. Somewhere between NW and WNW. It’s not as bad as it looked from eyeballing it. Here’s an illustration the eye’s movement on the last three satellite frames:

More importantly, as you can see, the center of the eye has now passed the longitude of Kingston (population 660,000). Barring a sudden and exceedingly unlikely NNW or due north wobble, the eyewall(s) will not hit Kingston. Phew. And notwithstanding the above graphic, the eye may stay offshore entirely, since it may well “wobble” back west again. The southern tip of the island will certainly get hit by at least the outer eyewall, though.

As of the 5pm advisory, Dean is "scraping" the south coast of Jamaica. The eye is 50 miles south of Kingston, moving west. No change in strength. … We, meanwhile, are at Babies R Us. And Becky is uber cute. :)

At 2pm, NHC says Dean is still at 145 mph; pressure is back up to 930 mb. The eye is 80 mi. southeast of Kingston, Jamaica, moving WNW.

(This is another double post between my weather blog WX-Man.com and Brendan’s)

Dr. Jeff Masters showed this Microwave satellite image of Hurricane Dean from around 7 AM EDT, or as Dr. Masters described it as “Think of this as a weather radar in space.” Like in the enhanced infrared satellite that has been shown here the red areas indicate the thunderstorm convection in the spiral bands and the eyewall. He then points out the the “incomplete double ring of echoes around the dark blue eye. Dean has two eyewalls, concentric around each other.”

This is very interesting to me and I will be the first to admit when I learn something new. I am a meteorologist, but I will be the first to admit that my weakest area in meteorology is Tropical Weather. He has a great discussion on what this “Double Eye” means for Jamaica and the Cayman Islands:

Jamaica is already receiving high winds and heavy rain from an outer spiral band. How bad will it get? The big question is if the eyewall will move over the island. Unfortunately for Jamaica, Dean has two eyewalls, forming concentric rings (Figure 1). The inner eyewall is 15 miles in diameter, and the outer eyewall is 37 miles in diameter. Winds of Category 3 and 4 strength are blowing in both eyewalls, as seen in the latest data from the SFMR surface winds taken by the Hurricane Hunters. So, Dean’s center has to pass more than 25 miles south of Jamaica for the island to be spared the worst of the hurricane. The nation’s capital, Kingston, lies on the southern portion of the island, and will be the hardest-hit major city. The tourist city of Montego Bay is on the northern part of Jamaica, and will fare much better.

The same story holds true for the Cayman Islands. Grand Cayman, the southernmost of the islands, it at greatest risk. If Dean passes more than 30 miles south of the island, they will miss seeing the outer eyewall of Dean and will fare relatively well. It’s going to be a close call, but it appears that both Jamaica and the Cayman will miss seeing the eyewall of Dean.

At the end of this post he gives his thoughts on Dean’s hits on the Yucatan near Cozumel and then south of the Texas/Mexico boarder and how this could be similar to Hurricane Emily.

Also this morning Eric Berger (SciGuy) isn’t ready to clear Texas from being threatened by Dean, but seems to agree a lot with Dr. Jeff Masters:

I’m also not ready to clear Texas yet as possibly being threatened by Dean, although all of the models, at a minimum, now bring the storm in for a final landfall nearly 200 miles south of the border. The models also are beginning to predict some weakening for this final landfall as Dean spends more time over the Yucatan.