ATL: IRMA - Post-Tropical - Discussion

[AxaltaRacing24]

Starting to get a bit worried in Jupiter. Just hope that we avoid the eyewall.

[PandaCitrus]

Hurricane Andrew wrote:
Is it a bit north of the track, or just wobbly?


I just noticed that too. Also looks to be moving pretty fast. Appears to go n of forecast point at a quicker rate. Wonder if that will have a bearing on the storm down stream?

The northern track would probably take out all the into Cuba model scenarios. Those seem to be the models that were the most west and threatened the gulf coast of Florida. That gives the storm more chances to continue remaining Cat 5 or making a play at the record books and getting stronger.

I'm curious about the effect little changes in speed and movement effect the models.

If Irma is going faster than forecast and more north, what does that do?

[ozonepete]

Anyone have the latest Dvorak T number? (and the best link so I can grab it myself going forward?

This is my favorite from CIMSS at the University of Wisconsin. Just click on the red letters ADT just under the global map and then select your cyclone, i.e. Irma and you'll get all the info you need.

http://tropic.ssec.wisc.edu/

[jlauderdal]

Starting to get a bit worried in Jupiter. Just hope that we avoid the eyewall.

Get prepared, you will worry less

[jlauderdal]

Anyone have the latest Dvorak T number? (and the best link so I can grab it myself going forward?

This is my favorite from CIMSS at the University of Wisconsin. Just click on the red letters ADT just under the global map and then select your cyclone, i.e. Irma and you'll get all the info you need.

http://tropic.ssec.wisc.edu/

Those barbers do a fine job with sat images

[decgirl66]

Titusville here (North Brevard County)
Have heard some people say effects here will be similar to what Matthew brought last year. Any thoughts from the more knowledgeable weather peeps? Or is it still to far out to answer that?

There is a distinct possibility that could be the case. Keep watching, especially the NHC, and check in here when you can.

Funny you should say that! I have been glued to this board for 2 1/2 days now!

[wjs3]

Anyone have the latest Dvorak T number? (and the best link so I can grab it myself going forward?

This is my favorite from CIMSS at the University of Wisconsin. Just click on the red letters ADT just under the global map and then select your cyclone, i.e. Irma and you'll get all the info you need.

http://tropic.ssec.wisc.edu/

Ozonepete, I'm logging in just because you're here. Fun times!

[HarryPotter]

Anyone have the latest Dvorak T number? (and the best link so I can grab it myself going forward?

This is my favorite from CIMSS at the University of Wisconsin. Just click on the red letters ADT just under the global map and then select your cyclone, i.e. Irma and you'll get all the info you need.

http://tropic.ssec.wisc.edu/

Thank you!

[Evil Jeremy]

New advisory forecast points:

3 days: Maybe 80 miles west of Andros Island
4 days: Fort Pierce, barely inland
5 days: Savannah, Georgia

[Scorpion]

It honestly doesn't seem possible to me that this area can possibly get much heavier damage than Frances and Wilma. We always seem to have a major hurricane buffer. I am definitely staying and fascinated about the thought of a Cat 4 going over me, but doubtful it will really happen.

[Spacecoast]

Forecasterjack said to ask him if we had any questions about Weather.us (Great site by the way!)...
I do, but would also appreciate anyone's knowledgable reply:

1.The wind speed parameter when displaying either US, or Euro models. Is this displaying wind speed at ground level(or close to ground level)?
2.Does the parameter "Gusts,3hr (mph)" translate to a gust of wind lasting for 3hrS?
3.How does the parameter "Wind - Mean spead" compare to NHC's 1 minute Average wind speed?
4.Also there seems to be a great difference between how the US and Eur wind speed when comparing the difference between Mean Speed and Gusts particular geographic area as the eye crosses...
5.The US (GFS) model seems to have very little difference on the east side of the wall between mean speed and gusts( toggling between the two parameters).....
The Euro displays much higher gust speed on the east wall as it rides the coast, but much lower mean speed.The mean speed seems to decline very rapidly just a few mile from the coastline.
Is this due to the HD resolution on the Euro vs SD GFS?
6. Which model, and parameter would be recommended for accuracy in determining the average & gust speed at ground level, comparable to NHC 1 minute average?
7. Also, what is the Wind Power - speed 330 ft only avail on Euro? not familiar with term Wind Power vs Wind speed.

Thanks in advance.

[tolakram]

ZCZC MIATCDAT1 ALL
TTAA00 KNHC DDHHMM

Hurricane Irma Discussion Number 32
NWS National Hurricane Center Miami FL AL112017
1100 PM AST Wed Sep 06 2017

Earlier radar observations from the San Juan WSR-88D showed a
concentric eyewall, and observations from an Air Force Hurricane
Hunter aircraft showed a secondary wind maximum over the northwest
quadrant. These phenomena may be associated with some weakening,
but since the central pressure hasn't risen much the intensity is
held at 160 kt at this time. Moreover, the concentric eyewall has
become less apparent in recent radar imagery. Considerable
lightning activity has been noted in the eyewall of Irma, which
research has shown to sometimes be a harbinger of weakening.
Notwithstanding, low vertical wind shear and warm waters along the
forecast track of Irma should allow it to remain a very powerful
hurricane during the next several days. The official intensity
forecast is similar to the previous one except at day 5 when
stronger shear should cause more weakening. This forecast is
generally above the intensity model consensus.

Irma continues on a west-northwestward heading at around 14 kt. A
ridge of high pressure over the western Atlantic should maintain
this course for the next 48 to 72 hours. Later in the forecast
period a shortwave trough moving into the southeastern United
States is likely to turn the hurricane northwestward to
north-northwestward. There has been a slight eastward shift in
some of the track guidance models, but since the models could shift
back to the west it is prudent to make little change to the
official forecast at this time. In any event, users are reminded
not to focus on the exact track since the average NHC track
errors at days 4 and 5 are about 175 and 225 miles, respectively.

KEY MESSAGES:

1. Irma is a potentially catastrophic category 5 hurricane and will
bring life-threatening wind, storm surge, and rainfall hazards to
Puerto Rico tonight, the northern coast of Hispaniola Thursday, and
the Turks and Caicos and southeastern and central Bahamas Thursday
and Friday.

2. Hurricane watches are in effect for the northwestern Bahamas and
much of Cuba. Irma is likely to bring dangerous wind, storm surge,
and rainfall to portions of these areas on Friday and Saturday.

3. The threat of direct hurricane impacts in Florida over the
weekend and early next week has increased. Hurricane watches will
likely be issued for portions of the Florida Keys and the Florida
peninsula on Thursday.


FORECAST POSITIONS AND MAX WINDS

INIT 07/0300Z 19.4N 66.8W 160 KT 185 MPH
12H 07/1200Z 20.3N 68.8W 155 KT 180 MPH
24H 08/0000Z 21.3N 71.7W 150 KT 175 MPH
36H 08/1200Z 22.1N 74.1W 145 KT 165 MPH
48H 09/0000Z 22.7N 76.3W 140 KT 160 MPH
72H 10/0000Z 24.0N 79.3W 135 KT 155 MPH
96H 11/0000Z 27.4N 80.3W 120 KT 140 MPH
120H 12/0000Z 32.0N 81.0W 95 KT 110 MPH

$$
Forecaster Pasch

NNNN

[CrazyC83]

000
URNT15 KNHC 070253
AF309 1511A IRMA HDOB 32 20170907
024400 2003N 06731W 6974 03087 9979 +101 +059 049067 069 049 005 00
024430 2002N 06730W 6970 03093 9996 +085 +063 052069 070 049 007 00
024500 2001N 06729W 6964 03090 0006 +071 +068 051067 071 048 011 03
024530 2000N 06728W 6971 03081 9997 +075 +074 063072 073 049 010 03
024600 1959N 06727W 6965 03081 9981 +083 +080 060072 073 049 006 00
024630 1957N 06725W 6974 03067 9965 +091 +076 064074 075 050 007 00
024700 1956N 06724W 6963 03071 9970 +079 +078 060074 077 049 010 03
024730 1955N 06723W 6970 03058 9961 +083 +083 061078 080 050 010 00
024800 1954N 06722W 6966 03056 9948 +086 +086 056077 080 056 014 03
024830 1953N 06721W 6961 03053 9944 +086 +086 044080 083 052 019 00
024900 1952N 06720W 6986 03018 9935 +088 +088 051078 083 059 016 03
024930 1951N 06718W 6947 03051 9926 +088 +088 044086 091 059 016 03
025000 1950N 06717W 6994 02996 9925 +089 +088 050085 090 057 025 03
025030 1949N 06716W 6947 03030 9902 +087 +087 051095 099 068 016 03
025100 1948N 06715W 6941 03037 9909 +076 //// 053094 095 063 006 01
025130 1946N 06714W 6962 02990 9884 +079 +074 053097 099 066 005 00
025200 1945N 06713W 6969 02980 9882 +074 +071 051101 101 067 010 00
025230 1944N 06712W 6968 02968 9858 +081 +072 050103 105 070 008 00
025300 1943N 06710W 6973 02949 9857 +070 +070 047108 110 074 022 03
025330 1942N 06709W 6972 02930 9843 +067 +065 043116 118 074 029 03
$$
;

[PandaCitrus]

It honestly doesn't seem possible to me that this area can possibly get much heavier damage than Frances and Wilma. We always seem to have a major hurricane buffer. I am definitely staying and fascinated about the thought of a Cat 4 going over me, but doubtful it will really happen.

Hopefully, you are in a newer home up to code. I wouldn't want to stay in a 70's or 80's era home in Cat 4 conditions unless it was retrofired for wind mitigation

[Hurricane Andrew]

NHC says shear for D5...I thought this was going to be shear-free.

[La Sirena]

New advisory forecast points:

3 days: Maybe 80 miles west of Andros Island
4 days: Fort Pierce, barely inland
5 days: Savannah, Georgia

I always find the Savannah tag weird....that storm has to get through Tybee, Wilmington, and Whitemarsh to get to Savannah.

[Bamagirl2408]

Evacuators- Talladega Superspeedway campground is offering free camping for anyone evacuating (if you need to go that far) tent and RV camping. Seen on Facebook

[tolakram]

3 day cone on South Florida now.

[1900hurricane]

Anyone have the latest Dvorak T number? (and the best link so I can grab it myself going forward?

Looks like a DT of 6.5 for a warm medium grey eye embedded in a black CDO and a white surrounding shade. White fails width requirements, reducing it from the 7.0 it was at earlier.

[tolakram]

 https://twitter.com/RyanMaue/status/905625399048196101



Ryan Maue ✔ @RyanMaue
Looking back at notable Category 5 hurricanes & how they compare with Hurricane #Irma at their peak:
Hugo (1989)
10:54 PM - Sep 6, 2017