Dr. Jeff Masters' WunderBlog

Dennis moving inland

Posted by: Dr. Jeff Masters, 12:52 AM GMT on July 11, 2005

Posted: 8pm EDT Sunday July 10
==========================

Here's the official word from NHC:

Radar observations indicate that Hurricane Dennis made landfall at 225 PM CDT on Santa Rosa Island between Navarre Beach and Pensacola Beach Florida. Data from the stepped frequency microwave radiometer on board the NOAA hurricane hunter aircraft, as well as flight-level observations from NOAA and Air Force Reserve aircraft indicate that the landfall intensity of Dennis was 115 to 120 mph--a Category 3 on the Saffir-Simpson hurricane scale.

And my comments:
Dennis is still a serious hurricane. A storm surge of 9-10 feet was reported up to 175 miles east of where Dennis made landfall, in the coastal areas just south of Talahassee. Major storm surge flooding is still occurring all along the Florida Panhandle. Water has pushed across Route 98 near Apalachicola and there has been structural damage there similar to what was observed in 1985 with hurricanes Kate and Elena. Saint Marks, Florida--200 miles east of Pensacola--is flooded. Inland flooding worse than Ivan's is occurring throughout Alabama in Florida in areas soaked last week by Tropical Storm Cindy with six inches of rain. Already, Dennis has dumped an addtional 4-8 inches. There have been several reports of tornadoes in both Alabama and Florida, and these tornadoes could very well turn out to be the major killers for this storm. Another area of concern is inland flooding over the Tennessee Valley later in the week--model forecasts show Dennis stalling out over southern Illinois, creating a potential serious flooding event there. Dennis will be a menace for many days to come.

Don't even look out east of the Leeward Islands, where a powerful tropical wave is already spinning and gathering some impressive deep convection around it. And don't look at the calendar, which says July 10, and think about what happens two months from now, on September 10--the peak of hurricane season.

Dr. Jeff Masters

Posted: 3pm EDT Sunday July 10
==========================
Dennis is finally coming ashore, just east of Pensacola, and about 30 miles east of where Ivan struck. The central pressure measured by the hurricane hunters has risen to 943 mb, and the strongest winds measured at 10,000 feet have fallen considerably. Dennis will probably be classified as Category 3 with 125-130 mph winds at landfall.

The eye has maintained its tiny 8 mile diameter, and the most extreme damage will be confined to a smaller area than Ivan. I wouldn't be surprised to see Dennis carve a channel straight through Santa Rosa Island, the barrier island offshore from Pensacola. The worst storm surge damage will occur in the East Bay of Pensacola Bay, where a storm surge of 15 feet could occur. Extreme wind damage will miss Pensacola's downtown, but will severely impact Milton, a town of 7,000 people just east of Pensacola. Whiting Field Naval Air Station, just 15 miles inland, will also suffer heavy damage.

Posted: 11am EDT Sunday July 10
==========================
Dennis finally peaked in intensity. The hurricane hunters found no further drop in pressure, and the winds have eased off a bit to 140 mph. The eye is a very tight 8 miles in diameter, which a hurricane cannot maintain for very long. This eyewall could start to collapse in the next few hours, which would probably reduce the peak winds at landfall down into the Cat 3 range. Add to that the fact that Dennis is now travelling over cooler 29 - 30C water, and I arrive at the conclusion that this storm will hit as a strong Cat 3/weak Cat 4. High tide is around noon today, so Dennis will not be hitting at the worst time possible. It could have been worse--but not much. Mobile looks likely to barely escape (again) having a huge storm surge roll up Mobile Bay, but Pensacola will receive another punishing blow from a major hurricane worse than last year's Ivan.

Posted: 7am EDT Sunday July 10
==========================
Latest hurricane recon showed a pressure drop to 931 mb, 1 mb lower than two hours ago. If Dennis comes ashore with that pressure, it would be the 7th most intense hurricane ever to strike the U.S. An additional pressure fall to 927 mb would rank it number four, behind only Camille, the 1935 Labor Day storm, and Andrew.

Dennis still looks on track for a an exact duplicate landfall where Hurricane Ivan hit along the Florida-Alabama border, just west of Pensacola. The storm surge from Dennis will be one the highest ever for the U.S., up to 15 feet in some locations. The all-time record is Hurricane Camilles's 24.6 feet (image credit: NOAA Photo Library). Expect extensive damage to the weakened dunes and beaches, new cuts opened all the way through barrier islands, and of course near-total destruction of all buildings where the 10-15 foot storm surge values occur. The tourist industry will take a very long time to recover in Pensacola.

Posted: 11pm EDT Saturday July 9
================================
Dennis has slowed down its rapid intensification, and is probably near its lowest pressure. The last recco flight found only a 1 mb drop in 1.5 hours, compared to 5 mb over the previous 2.7 hours and 11 mb in the 1.5 hours before that. Dennis is still traversing a warm pool of 32C waters, so may continue to drop in central pressure until about 3am, when it passes into cooler 30C waters. The winds will continue to increase to Category 4 strength until perhaps 6am, peaking out at 145 mph or so. From 3am until landfall, Dennis will be traversing 28 - 30C waters, which are about what it was seeing earlier today near Cuba. At this time, a slow weakening trend may result as it undergoes an eyewall replacement cycle.

If you're thinking of evacuating now, it may be too late. It's better to be riding out the storm at home than caught in a traffic jam on the expressways.

Posted: 9pm EDT Saturday July 9
===============================
Dennis continues its impressive intensification; the pressure dropped 16 mb in 3 hours, which matches the rapid deepening seen in Hurricane Charley last year shortly before it made landfall. Dennis's intensification is probably in part due to the fact it is traversing a narrow pool of 32C (90F) water. The eye has shrunk another 2 miles in diameter to 10 miles, and likely will shrink a little more then break apart like it did before hitting Cuba. I expect Dennis's winds will continue to increase to about 145 - 150 mph to bring it in equilibrium with its new pressure.

Dennis continues to break the rules for what is usual for a hurricane. In my previous blog entry, I wrote that it is very unusual for a major hurricane to regain its former intensity after a long crossing over land. However, Dennis is poised to do just that.

Aircraft recon just measured a central pressure of 947 mb at 5:15pm, an 11 mb drop in 90 minutes--a rarely observed rate of intensification. The eyewall shrank from 15 miles in diameter to 12 miles, and the satellite presentation confirms that the storm is undergoing explosive deepening. Dennis will surely be a strong Category 4 storm in about 6 hours, when the winds have time to catch up to the pressure falls, and Category 5 is not out of the question. Satellite imagery shows an outer wind maximum is probably forming, meaning Dennis will enter another eyewall replacement cycle tonight after this phase of explosive deepening is over.

The current track of the storm is more WNW than NW, and is likely a temporary wobble similar to two others this storm has already done. I expect Dennis will shortly resume its previous northwest track. The most recent wobble occurred as the storm was doing its previous rapid intensification cycle just before it hit Cuba. The current wobble is enough to probably spare Panama City the worst of the hurricane, but increases the danger to Mobile. A direct hit by Dennis just west of Mobile could easily challenge Hurricane Andrew as the most expensive hurricane in history. Dennis's storm surge of 15-20 feet would push into Mobile Bay and cause tens of billions in destruction. Even if Dennis hits further east near Pensacola, as I still expect, the damage will surpass Ivan's $13 billion and Charley's $14 billion to make Dennis the second costliest hurricane on record.

If you want to watch live windows media player feeds, check out:

CBS WFOR MIAMI FL.:
http://dayport.wm.llnwd.net/dayport_0025_live

CBSNEWS.COM FEED 1
mms://eyenet.wm.llnwd.net/eyenet_livenews1 (Showing the same as above)

CBS WKRG MOBILE AL:
mms://wmbcast.mgeneral.speedera.net/wmbcast.mgeneral/wmbcast_mgeneral_jul072005_1144_93320

CBS WIAT PANAMA CITY:
mms://wmbcast.mgeneral.speedera.net/wmbcast.mgeneral/wmbcast_mgeneral_jul072005_1144_93323

http://www.weatherserver.net/livevideo.htm will show all 3 feeds will at once. Thanks to Jason@Weatherserver.net, who posted this info on the WX-TALK@LISTSERV.UIUC.EDU email list.

Entry from 10am EDT
====================
Cuba did the U.S. an enormous favor by absorbing Dennis' worst punch. It's pretty rare for a major hurricane to regain its former intensity after a long land crossing, and Dennis has only until Sunday evening to regroup. While I do believe Dennis will reintensify to a Category 3 hurricane-- which will be plenty bad for the storm-weary residents of the Florida Panhandle, Alabama, and Mississippi--a return to the Cat 4 monster that ravaged Cuba is pretty unlikely. A search back into the hurricane archives for similar storms reveals the case of Hurricane Georges, a strong 1998 Category 3 hurricane that smashed the Dominican Republic. After traveling down the length of Cuba, Georges popped off Cuba as a Category 1 hurricane about the same place Dennis did. Gerorges gradually intensified to a borderline Category 2/3 hurricane with a 12-foot storm surge and 110 mph winds before it hit Mississippi, and did about $5 billion in damage to the U.S. mainland. I'm betting Dennis will have a very similar impact.

It takes at least 12-24 hours for a hurricane to re-establish its inner core eyewall structure after a major disruption like Dennis suffered, which doesn't give it much time before landfall. I give Dennis a 10% chance of hitting as a Category 4, 50% as a Category 3, 30% as a Category 2, and 10% as a Category 1 or weaker. As for landfall location, the computer models are now in pretty unanimous agreement about a Mobile/Pensacola landfall, now that the distraction of dealing with the Cuba interaction is over. When the models all come together like this, it's usually a pretty sure bet that landfall will be within 50 miles of the target.

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51. Astrophysics 12:06 PM GMT on July 10, 2005
Does anyone have the 8 am advisory or is there no advisory at this time? I think the winds are probably now at 155 mph. Member Since: June 10, 2005 Posts: 0 Comments: 45

52. mobilehurricane 12:08 PM GMT on July 10, 2005
no update yet--but a sharp turn to the north is definite now

53. wxgssr 12:44 PM GMT on July 10, 2005
Last few framee indicate moving back to the NW. Still on track for West Mobile bay to P'Cola...

54. oriondarkwood 1:37 PM GMT on July 10, 2005
This is a post I wrote a couple of days ago: ________________________________ Date: 1:57 PM GMT on July 06, 2005 By: oriondarkwood Here is my non-expert opinion one where I think Dennis is going and what will it hit as. I believe Dennis will hit the Flordia panhandle 50 miles east of Gulf Shores, Alabama (Ivan hit this location last year). It will hit as a weak Cat 4 storm _____________________________________ Current Dennis is at 145MPH making it a medium Cat 4 storm and if it hits around Mobile, AL that is 46 miles west of Gulf Shores. Again scary I made this prediction 4 days ago. Member Since: July 5, 2004 Posts: 51 Comments: 41

55. taco2me61 1:49 PM GMT on July 10, 2005
well this thing is scary we still don't know which way it is going, although it is moving North right now but is this a jog then more west or is this the last path it will take. I'm not sure... With 931mb this is BAD for anybody in the path of Dennis where ever it goes... Please be safe and pay close attention to this Very Strong Storm... Member Since: July 7, 2005 Posts: 6 Comments: 2763

56. oriondarkwood 2:05 PM GMT on July 10, 2005
taco2me61, I know, I don't mean to belittle the power of this storm nor not understand the impact its going to have on a region that is still recovering from Ivan. But just a FYI I am not anywhere near this. I live in upstate NY but I grew up in NC so I have seen the power of these storms up close. Member Since: July 5, 2004 Posts: 51 Comments: 41

57. Astrophysics 2:06 PM GMT on July 10, 2005
Pressure just dropped another mb to 930 mb. I think it is a catagory 5 hurricane but the weather people are just afraid or in denial about it being that strong. Member Since: June 10, 2005 Posts: 0 Comments: 45

58. Hawkeyewx 2:13 PM GMT on July 10, 2005
To be a cat 5 the pressure needs to be about 920 mb or lower. Member Since: July 5, 2005 Posts: 2 Comments: 1922

59. HurricaneSurvivor 2:17 PM GMT on July 10, 2005
The surge is already up in Pensacola about 2 feet. Looks bad here, I'm scared... Member Since: July 10, 2005 Posts: 0 Comments: 16

60. paulfrmpasschristian 2:30 PM GMT on July 10, 2005
Our local weather guy out of New Orleans who has a great record says he doesn't believe the track; that it will hook a little West at the last minute and will hit Navarre. Just his opinion. That would be great for you Mobilers and even help Pens .

61. paulfrmpasschristian 2:32 PM GMT on July 10, 2005
How close are you to the water Survivor?

62. Hawkeyewx 2:33 PM GMT on July 10, 2005
where is Navarre? I can't find it on the map Member Since: July 5, 2005 Posts: 2 Comments: 1922

63. paulfrmpasschristian 2:35 PM GMT on July 10, 2005
Its just East of Pen, on the water

64. Hawkeyewx 2:36 PM GMT on July 10, 2005
Ok, I found it, just east of Pensacola Bay. Member Since: July 5, 2005 Posts: 2 Comments: 1922

65. rhythmarmy 2:36 PM GMT on July 10, 2005
Well anyone else get the impression that its going to be a Ft Walton Beach area hit in regards to the most intense upper east quad? I woke up hoping for a moore westerly jog since 3 am but no joy on that. Geeze I hope my Dad came down from AL and got my Mom out of Niceville. Sister is staying... Im worried...

66. Hawkeyewx 2:46 PM GMT on July 10, 2005
There has been a definite nw movement in the last couple hours. That continued movement would spare Fort Walton Beach the worst. Member Since: July 5, 2005 Posts: 2 Comments: 1922

67. paulfrmpasschristian 2:49 PM GMT on July 10, 2005
Panama city picking up the eye on this radar

68. TampaSteve 2:54 PM GMT on July 10, 2005
Cat 4...140 MPH...looking at 15+ ft storm surge over the already carved-up dunes in P'cola...looks like Dennis is gonna finish the job Ivan started...I feel for you guys up there in the Panhandle...good luck...stay safe...

69. Astrophysics 3:13 PM GMT on July 10, 2005
Does anyone see the next low pressure out in the atlantic that might develop. Link Member Since: June 10, 2005 Posts: 0 Comments: 45

70. HurricaneSurvivor 3:40 PM GMT on July 10, 2005
Hawkeye, I'm just slighly East of Pensacola on the water... here is my house picture taken from by the garage just days ago... http://www.gulfcoastmuscle.org/bishir/picsandvids/insurvidIVAN/DSC01100.JPG Notice the new windows stickers still and the yard being worked on. I was 95% finished with my house and now it will be flooded and probably blown down this time. Water is about 60 feet from my front door and the house is 10.4 feet above water. I moved here thinking water would never rise that high in the bays. Little did I know storm surge is WORST in the bays. I didn't get the house finished in time to sell before this storm. :( Member Since: July 10, 2005 Posts: 0 Comments: 16

71. paulfrmpasschristian 3:43 PM GMT on July 10, 2005
survivor, my parents have a condo at the Eden on perdido. They just opened that place up for rentals about 6 weeks ago from Ivan

72. paulfrmpasschristian 3:45 PM GMT on July 10, 2005
Where are you staying now

73. rhythmarmy 4:00 PM GMT on July 10, 2005
Hawkeye. Thanks!! Funny enough that is my Dads nickname! and yep I just got back in after an hour or so and it looks like they'll be somewhat more safe.

74. oriondarkwood 9:20 PM GMT on July 10, 2005
Well it hit, in the 50 miles range east like I predicted but only as a strong cat 3. So no record cat 4 strike for Dennis but still alot of damage and possible deaths for a region still reeling from Ivan Member Since: July 5, 2004 Posts: 51 Comments: 41

75. Raine54 12:57 AM GMT on July 11, 2005
Posting from Niceville... power just got restored..I can't believe the relatively little damage apparent.. mostly just small limbs and a few shingles here and there from my limited observations.. hope no lives were lost, haven't heard word from the Navarre area yet

76. IRememberIvan 1:10 AM GMT on July 11, 2005
http://www.ssd.noaa.gov/PS/TROP/DATA/RT/EATL/IR4/20.jpg ...and here we go again.

77. SWFL 1:11 AM GMT on July 11, 2005
Weather wise this is going to be one LONG summer(hurricane season). I can't believe there is another "area of concern" in the Atlantic again.I had thoughts this weekend of another Charlie that Dennis would be making a hard right turn into the south FL area. I pray all is okay up in the panhandle and no lives were lost. Property can be replaced as many of you well know. Member Since: July 8, 2005 Posts: 0 Comments: 14

78. LongStemRose 1:43 AM GMT on July 11, 2005
Anyone hear from HurricaneSurvivor? Hope he's OK. Any word on P'cola NAS? My son is supposed to report there for flight school in a couple of months. Trust all who have been on this blog have come thru safe. It's going to be a long season.

79. CoalCracker 2:41 AM GMT on July 11, 2005
"For Emily, Whenever I May Find Her." Please not Florida AGAIN.

80. IRememberIvan 2:47 AM GMT on July 11, 2005
In 5 days, the GFDL puts Emily NW of Puerto Rico as a Cat 4, moving WNW toward SE FLA. Emily's gonna pull an Andrew.

81. windchaser 2:55 AM GMT on July 11, 2005
Dr. Jeff --- I sure enjoyed the Blogs about Dennis. Great information.

82. HurricaneKing 3:04 AM GMT on July 11, 2005
Here comes Td5. Member Since: July 6, 2005 Posts: 71 Comments: 2430

83. creekchub00 3:05 AM GMT on July 11, 2005
I think the wave behind TD has potential to develop also. The GFS picks it up and starts a substantial move to the North with it before it reaches the Carribean. The GFS really didn't even locate TD5 very well. Tomorrow we should get to see some better models.

84. creekchub00 3:26 AM GMT on July 11, 2005
I just posted my first entry for T.D. #5 http://www.thecaptainsdeck.net/hurricanes/modules.php?op=modload&name=News&file=article&sid=17&mode=thread&order=0&thold=0 Come register and post comments, looking for people to help me predict these and write articles as well. email thecapt@thecaptainsdeck.net if you are interested in helping.

85. HurricaneSurvivor 3:47 AM GMT on July 14, 2005
I made it! The power was just restored and overall the storm was not as strong as expected and the storm surge was closer to 5 feet in my area comparted with Ivan's 13. I made my own blog about it. THanks for being concerned.. The eye passed over the house and it was a very cool! Member Since: July 10, 2005 Posts: 0 Comments: 16

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