charlottefl
Weather Hobbyist
Reged: Mon
Posts: 94
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As long as you are in that cone, there is a posibility that you are going to be hit. Even with the great advances that they have made though in forecasting it is too hard to tell 3 or 4 days out the exact landfall location let alone 12 hours out. The best thing to do is prepare and keep up with the updates. If you have any doubts , it might be a good time for a weekend trip out of town. Best of luck to everyone in the path.
Hurricane '04 (Port Charlotte)
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nl
Storm Tracker
Reged: Tue
Posts: 207
Loc: nsb,fl
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does anyone have live traffic links for galveston area with live cams and info about the car rate like we do in fl? 
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Nutmeg
Registered User
Reged: Thu
Posts: 4
Loc: New England
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Good coverage of the evacuation situation and other news in Galveston...KHOU TV...there must be cams on this site, too.
http://www.khou.com/news/local/
edited table breaking link...~danielw
Edited by danielw (Tue Sep 20 2005 07:40 PM)
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Random Chaos
Weather Analyst
Reged: Sat
Posts: 1024
Loc: Maryland
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We are down to 969mb. Eye is clearly visible on IR. She's still growing.
604
URNT12 KNHC 202249
VORTEX DATA MESSAGE
A. 20/22:24:20Z
B. 23 deg 56 min N
082 deg 21 min W
C. 700 mb 2847 m
D. NA kt
E. NA deg nm
F. 232 deg 075 kt
G. 138 deg 024 nm
H. 969 mb
I. 9 C/ 3049 m
J. 15 C/ 3040 m
K. 12 C/ NA
L. OPEN E
M. C31
N. 12345/ 7
O. 0.02 / 1 nm
P. AF302 1218A OB 15
MAX FL WIND 89 KT NW QUAD 20:00:50 Z
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KATFIVE
Weather Watcher
Reged: Sun
Posts: 25
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You guys know much and I would like some clarification as to the info in the recons. What ratio do you use to extrapolate surface winds from flight level winds? And what about all this talk about the temperature differential between the inner and outer wall? Is there some rough rule of thumb to figure out intensity from this differential. Finally what is the significance of the 700mb height? I appreciate your illumination for the hurricane beginner.
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MissBecky
Weather Guru
Reged: Thu
Posts: 112
Loc: Ft. Myers, FL
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Try these.
http://www.galveston.com/webcams/
http://www.khou.com/news/webcams/
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ShanaTX
Storm Tracker
Reged: Mon
Posts: 226
Loc: Texas
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Local TV mets here are starting to compare to Carla 1961 ... the Cat 4 storm that covered the *entire* Texas coast in hurricane force winds and remained a hurricane until it was up here near Austin. And they're pointing out that the takes it right over Austin :rolling eyes: I think they're getting a little hyped... but just looking at the size of ... I guess it is possible ...
They're talking about hurricane kits and loss of electricity.
Considering that Austin is where thousands of evacuees are heading to (ALL the hotels in Austin and Round Rock are booked, and the Red Cross says there is room for 45000 evacuees in local schools....) I'm hoping it's not going to be more than TS strength here.
Question ... Has anyone seen a projected size estimate (not strength) for ? Is she supposed to be a very large storm sizewise?
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Clark
Meteorologist
Reged: Wed
Posts: 1710
Loc:
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Extrapolation of surface winds from flight-level data depends based upon any given storm -- no two storms are alike -- as well as the level at which the winds were reported. Inside of the eyewall, the reduction factor from 700mb is generally 0.91. With , it seems to be a bit closer to 1.0 right now given the available data.
The temperature differential between the eye and eyewall is a measure of the efficiency of the storm and its intensity. Simply put, the subsidence within the eye can be used as a proxy for relative storm efficiency and intensity. Subsidence generally leads to heating; thus, you see temperatures in the eye warmer than those outside of it. The greater the differential, the greater the subsidence and the greater the intensity of the storm. It should be noted that the subsidence in the eye is a necessary response to the strong rising motion in the eyewall and away from the center in the convective moat & feeder bands.
The 700mb height can be used as a measure of the storm's intensity at the surface and in the lower levels. Generally, 700mb heights average around or just above 3000m. Lower heights generally lead to lower pressure and thus a more intense storm; with , we haven't seen 700mb heights being all too low quite yet -- most recent of 2847m is fairly low, but nothing like the 2200-2400m seen with . It's not hard and fast, however, and will vary from storm to storm.
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Thunderbird12
Meteorologist
Reged: Thu
Posts: 644
Loc: Oklahoma
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The adjustment from flight-level to surface winds depends on the level that the plane is flying at. The most typical levels are 700mb, in which case FL winds are multiplied by 0.9 to get surface winds, and 850mb, in which case FL winds are multiplied by 0.8. These estimates may be superseded, though, if there is other data available that gives a better idea of the surface winds.
A well-developed tropical cyclone will have the warmest temps at the center, so a stronger or developing system will have a greater temperature difference between the eyewall and the eye. I am not familiar with any rules of thumb about how the temperature difference corresponds to intensity, but others around here would know more than I do.
As for 700mb height, typically the surface pressure decreases as the 700mb height decreases, and vice versa. 700mb height generally doesn't tell you anything you can't get from the surface pressure, though it is a good idea to compare the change in 700mb height between obs to the change in surface pressure to see if anything funny might have happened with the dropsonde, causing a misleading pressure reading.
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JYarsh
Verified CFHC User
Reged: Wed
Posts: 11
Loc: Virginia Beach, VA
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WOW, the eye has really exposed itself in the last hew frames....
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danielw
Moderator
Reged: Wed
Posts: 3525
Loc: Hattiesburg,MS (31.3N 89.3W)
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While some aren't keen on my rough formula. I simply take the Max Flight Level Wind and change the knots to mph.
Last Vortex has 89kts MFLWind. Roughly 89mph at surface.
Formula for 700mb would be:
89 x 1.15=102.35mph MFLW x 0.91= 93.14mph at surface.
The 89kts to 89mph is the quick formula. And gives a rough estimate of the lower end of the maximum surface winds.
Here's the Official page on Eyewall Wind Profiles.
http://www.nhc.noaa.gov/aboutwindprofile.shtml
http://www.nhc.noaa.gov/aboutwindprofile.shtml#fig1
Edited by danielw (Tue Sep 20 2005 07:54 PM)
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jr928
Weather Guru
Reged: Fri
Posts: 101
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living in MS and having spent the last 3 weeks supplying items to the ravaged southern part of the state, I would hope every news outlet near houston is evacuating everyone within the cone. These days it just doesn't make sense to hang around.
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danielw
Moderator
Reged: Wed
Posts: 3525
Loc: Hattiesburg,MS (31.3N 89.3W)
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BULLETIN
HURRICANE INTERMEDIATE ADVISORY NUMBER 13A
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
8 PM EDT TUE SEP 20 2005
...DATA FROM THE KEY WEST NOAA DOPPLER RADAR AND AN AIR FORCE RESERVE UNIT RECONNAISSANCE AIRCRAFT INDICATE MAXIMUM SUSTAINED WINDS HAVE INCREASED TO NEAR 105 MPH...180 KM/HR...WITH HIGHER GUSTS.
RITA IS A STRONG CATEGORY HURRICANE ON THE SAFFIR-SIMPSON SCALE.
ADDITIONAL STRENGTHENING IS FORECAST DURING THE NEXT 24 HOURS...AND WILL LIKELY BECOME A CATEGORY THREE OR MAJOR HURRICANE ON WEDNESDAY.
HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 45 MILES... 75 KM...FROM THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 140 MILES...220 KM. DURING THE PAST HOUR...A GUST TO 70 MPH WAS REPORTED AT THE KEY WEST INTERNATIONAL AIRPORT...AND A SUSTAINED WIND OF 53 MPH WITH A GUST TO 62 MPH WAS REPORTED AT DRY TORTUGAS.
THE MINIMUM CENTRAL PRESSURE RECENTLY REPORTED BY RECONNAISSANCE AIRCRAFT WAS 969 MB...28.61 INCHES...
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danielw
Moderator
Reged: Wed
Posts: 3525
Loc: Hattiesburg,MS (31.3N 89.3W)
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URNT12 KNHC 210027
VORTEX DATA MESSAGE
A. 21/00:09:50Z
B. 24 deg 00 min N
082 deg 41 min W
C. 700 mb 2818 m
D. NA kt
E. 000 deg 000 nm
F. 294 deg 086 kt
G. 213 deg 014 nm
H. 967 mb
I. 8 C/ 3053 m
J. 15 C/ 3050 m
K. 9 C/ NA
L. CLOSED WALL
M. C32
N. 12345/ 7
O. 0.02 / 1 nm
P. AF302 1218A OB 19
MAX FL WIND 94 KT NW QUAD 22:34:30 Z
note: Recon found Max Flt Lvl Wind of 103kts.
About 11 minutes after this Vortex was transmitted.~danielw
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Psyber
Storm Tracker
Reged: Fri
Posts: 231
Loc: Ontario, Canada
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Hate to say that I told you so but I told you so...it slowed down. Lets just hope it doesn't slow anymore or every single model is going to explode. 
967...and dropping. ouch.
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Random Chaos
Weather Analyst
Reged: Sat
Posts: 1024
Loc: Maryland
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That's a drop of 27mbs in 24 hours, or an average of a mb an hour. If it sustains this rate, we could see 940mbs this time tomorrow...
We've got a monster forming.
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Psyber
Storm Tracker
Reged: Fri
Posts: 231
Loc: Ontario, Canada
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Closed eyewall, fairly stable eye...and it's a looong way out across fairly warm water before it hits land. I would completely agree with you.
--------------------
The safest way to deal with a potential Hurricane hitting you...is to leave and just not be there at all.
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SirCane
Storm Tracker
Reged: Tue
Posts: 249
Loc: Pensacola, FL
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Is it possible that could make a NW turn sooner than predicted?
--------------------
Direct Hits:
Hurricane Erin (1995) 100 mph
Hurricane Opal (1995) 115 mph
Hurricane Ivan (2004) 130 mph
Hurricane Dennis (2005) 120 mph
http://www.hardcoreweather.com
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danielw
Moderator
Reged: Wed
Posts: 3525
Loc: Hattiesburg,MS (31.3N 89.3W)
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Interesting as it may be. I haven't seen any indication of an Eyewall Replacement Cycle-(ERC)...yet!
I would think that after 18 hours of dropping pressure she should start an .
However her Eye is reported at "C32". 32 nautical mile Eye. A bit large to start an , but I don't know of any parameters for .
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HanKFranK
User
Reged: Mon
Posts: 1841
Loc: Graniteville, SC
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startin' with . pressure has been falling about 1-1.5mb hr all day. that's steady intensification... nothing outlandish. at 967mb the storm is nearing the traditional cat 3 threshold. track is over post-katrina waters.. at the speed it's moving the thinned warm layer will probably be enough to support a cat 4. it'll probably be there around tomorrow night, then go through eyewall cycles as it moves into the western gulf. the western gulf isn't stirred up, so friday the storm should be moving over deep mid 80s waters. the storm should be oscillating between and.. say, hugo levels of intensity as it will probably be sucking down a little subsidence here and there and be revving up and down. it could hit anywhere in this range, really no way to tell what stage it will be in. lot of the models are showing a harder turn near the coast on saturday... weakening the ridge even further than before... so my gentle curvature/earlier landfall idea may be toast. still not going to go later than saturday morning, going to keep it near sargent, tx. the official is further down the coast near palacios, but that's probably just due to the /ukmet that keep sending it into south tx. the rest of the consensus keeps painting the area from matagorda bay up to high island, and i'm staying put in the middle. worst case scenario is that it hits brazoria county directly and the inner core/right quad moves over the greater houston area... that's in the window, but most of the guidance is hanging west of there. that's still quite a lick, though. worth noting that the inland flood threat to western la, east tx, arkansas is increasing as a lot of guidance is either taking the storm sharply eastward or slowing it down in this region... should train a good deal of persistent rainfall over the region.
rest of basin: philippe can't get west thanks to that trough weakness/strong upper low in the central atlantic.. keeping the storm weaker and even further east than earlier predicted. 97L has fed into the eastern side and lost definition. some of the energy is getting pivoted around and up under that upper low... should keep an unsettled area associated with it that migrates toward the bahamas and perhaps tries to flare over the weekend as high pressure builds over the eastern u.s./western atlantic. it'll be in a shear zone and will take time to evolve, if anything. persistent storm signature showing up near the eastern caribbean near the end of the month as part of the same pattern-pulse that joe b spotted. is showing a couple of wannabe features in the east atlantic as well, but it's getting kinda late in the season for those to do much.
HF 0056z21september
Edited by HanKFranK (Tue Sep 20 2005 08:58 PM)
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