Major Hurricane Irma

[SnoSki14]

46 minutes ago, SN_Lover said:

Not with this look...Still a week+ out. But with this look, a re-curve is highly likely. 

 

That shows building heights north of the storm, definitely not an OTS look if the storm is not far north enough to take advantage of the weakness. 

OTS is the most likely scenario this far out but odds are probably 65-70 vs. the climo 90 percent at this time based on it's present location. 

[NJwx85]

000
WTNT41 KNHC 012050
TCDAT1

Hurricane Irma Discussion Number  10
NWS National Hurricane Center Miami FL       AL112017
500 PM AST Fri Sep 01 2017

Well, that eyewall replacement cycle didn't last long.  Satellite
images indicate that the cycle is now complete, with Irma displaying
a larger warm eye.  The initial wind speed has been set to 105 kt,
in agreement with the CIMSS ADT.  Since the eyewall cycle is
finished, some strengthening is possible, although SSTs are
currently pretty marginal.  Although no increase in winds is shown
in the short term, this could be conservative.  During the next few
days, water temperatures along the track will warm significantly,
but there could be some higher shear, and of course more eyewall
replacements.  The forecast is a compromise between the
statistical/dynamical models, which bring the intensity down then up
again, versus the global models and hurricane models, which show a
rather strong cyclone.

The westward turn of Irma has begun, and the current motion is
275/12.  A building mid-level high should cause the hurricane to
turn west-southwestward tomorrow and continue through early next
week.  Later on, Irma should reach the southern periphery of the
ridge, and begin to move west-northwestward.  The biggest change
since the last forecast is that the GFS and its ensemble has
trended southwestward, toward the unwavering ECMWF model on the
track forecast.  Given the trend in guidance, little change is made
to the official track prediction, although the corrected consensus
models and the HWRF are now southwest of the latest forecast.

KEY MESSAGES:

1. Irma is expected to be a major hurricane when it approaches the
Lesser Antilles early next week, producing rough surf and rip
currents.  Irma could also cause dangerous wind, storm surge, and
rainfall impacts on some islands, although it is too soon to specify
where and when those hazards could occur. Residents in the Lesser
Antilles should monitor the progress of Irma through the weekend and
listen to any advice given by local officials.

2. It is much too early to determine what direct impacts Irma will
have on the continental United States. Regardless, everyone in
hurricane-prone areas should ensure that they have their hurricane
plan in place, as we are now near the peak of the season.


FORECAST POSITIONS AND MAX WINDS

INIT  01/2100Z 18.8N  39.1W  105 KT 120 MPH
 12H  02/0600Z 18.9N  40.9W  105 KT 120 MPH
 24H  02/1800Z 18.5N  43.4W  105 KT 120 MPH
 36H  03/0600Z 17.9N  45.7W  105 KT 120 MPH
 48H  03/1800Z 17.2N  47.9W  105 KT 120 MPH
 72H  04/1800Z 16.4N  52.2W  110 KT 125 MPH
 96H  05/1800Z 17.0N  56.5W  110 KT 125 MPH
120H  06/1800Z 19.0N  61.0W  115 KT 130 MPH

[Hazey]

She's even prettier than yesterday. 

It's remarkable what a full unfettered ERC can do. Just think what a few more can do with a more favourable environment.

[Hoosier]

With all these track comparisons, one that wasn't mentioned was Connie in 1955. Could be reasonable or may not be, which is the point I'm making.  We don't have a good handle on the exact synoptic scale details at this point, so these comparisons to past storms at 10 days out are next to useless.  

[donsutherland1]

For some historical context, since 1851 six tropical cyclones that were either hurricanes or went on to become hurricanes passed within 50 nautical miles of Irma's 5 pm location (18.8°N 39.1°W).

One of those six systems went on to make U.S. landfall. Five did not.

The storm that made landfall was the "Sea Islands" hurricane of 1893. That storm move north-northwestward off the Florida coast and then made landfall in extreme northeastern Georgia before moving across South Carolina as it gradually recurved. That hurricane made landfall as a Category 3 storm (100 kts) and brought Category 3 winds to parts of Georgia and South Carolina and Category 1 winds to North Carolina.

See Hurricane #6: http://weather.unisys.com/hurricane/atlantic/1893/index.php

In the case of this hurricane, ridging was expanding westward to its north, which precluded an earlier turn out to sea. This storm also saw a period of time where it tracked west-southwestward, something that is forecast by some of the guidance for Irma.

It's too soon to be confident in any landfall for Irma. At the same time, it would be premature to rule it out either, even as climatology would favor this outcome.

 

[Joe4alb]

If nothing else at the moment, Irma looks simply amazing. 

[SN_Lover]

Not much change at hour 48 on the GFS. 

[bluewave]

I believe Irma will be the first major hurricane of the satellite era to lose more than 2 degrees of latitude in a WSW dip in that part of the Atlantic.

12H  02/0600Z 18.9N  40.9W  105 KT 120 MPH
 24H  02/1800Z 18.5N  43.4W  105 KT 120 MPH
 36H  03/0600Z 17.9N  45.7W  105 KT 120 MPH
 48H  03/1800Z 17.2N  47.9W  105 KT 120 MPH
 72H  04/1800Z 16.4N  52.2W  110 KT 125 MPH

[SN_Lover]

Harvey NE of the 12z run at 108. things are looking slightly better on CONUS though....

[Eduardo]

2 minutes ago, bluewave said:

I believe Irma will be the first major hurricane of the satellite era to lose more than 2 degrees of latitude in a WSW dip in that part of the Atlantic.

12H  02/0600Z 18.9N  40.9W  105 KT 120 MPH
 24H  02/1800Z 18.5N  43.4W  105 KT 120 MPH
 36H  03/0600Z 17.9N  45.7W  105 KT 120 MPH
 48H  03/1800Z 17.2N  47.9W  105 KT 120 MPH
 72H  04/1800Z 16.4N  52.2W  110 KT 125 MPH

That's a remarkable stat, Chris.  I usually let the climo be my guide when it comes to tracking these things, but in Irma's case, my confidence is reduced.  Odds usually disfavor a US LF (and still do at this point here IMO), but that said, the probability here seems higher than usual for a storm at her strength and location.

[Random Chaos]

18z GFS @ hr114 looks remarkably close tomtoday's 6z GFS, even down to the ridge and trough development.

[SN_Lover]

Trough needs to go more negative or it's a fish. 

[nycsnow]

11 minutes ago, SN_Lover said:

Trough needs to go more negative or it's a fish. 

Or phase 

[SN_Lover]

1 minute ago, nycsnow said:

Or phase 

that's what a negative trough causes. looks like LF on the 18z imminent.  

[Ralph Wiggum]

Run to run changes are absurd, as expected at this range.

Wow!



Sent from my LG-V410 using Tapatalk

[nycsnow]

1 minute ago, SN_Lover said:

that's what a negative trough causes. looks like LF on the 18z imminent.  

No I know, i meant those are our only 2 options lol, looking like it'll phase??

[Hoosier]

The differences with the handling of that trough between the 12z and 18z runs is laughable, though not unexpected at this range.

[SN_Lover]

1 minute ago, nycsnow said:

No I know, i meant those are our only 2 options lol, looking like it'll phase??

Think so. This trough is throwing the models for a loop. 

[Random Chaos]

Just now, Hoosier said:

The differences with the handling of that trough between the 12z and 18z runs is laughable, though not unexpected at this range.

Why we need some good pacific recon flights

[hawkeye_wx]

 

1 minute ago, Hoosier said:

The differences with the handling of that trough between the 12z and 18z runs is laughable, though not unexpected at this range.

The models have no clue what that trough is going to look like.

[BTRWx]

21 minutes ago, SN_Lover said:

Trough needs to go more negative or it's a fish. 

That's pretty unlikely this time of year too.

[LandofLincoln]

This run is a bit deceiving. The path is not that much different, but pretty much everything at the upper level is.

[nycsnow]

Mind you per gfs it's raining a lot in the mid Atlantic northeast as Irma approaches 

[SN_Lover]

LOL HYPE HYPE HYPE

Hurricane Irma Could Slam Into United States As Category Five Storm

http://www.iflscience.com/environment/hurricane-irma-slam-united-states-category-five-storm/

[SN_Lover]

Whoever made the sandy comment before jinxed this run. 

[nycsnow]

Oh my gfs is gonna destroy NYC nj etc (just one run obv)

[Tatamy]

This is a doomsday run for the NYC metro area... LOL

[Hoosier]

This is the NYC weenie run.  #resistthehype

[wxmx]

36 minutes ago, bluewave said:

I believe Irma will be the first major hurricane of the satellite era to lose more than 2 degrees of latitude in a WSW dip in that part of the Atlantic.

12H  02/0600Z 18.9N  40.9W  105 KT 120 MPH
 24H  02/1800Z 18.5N  43.4W  105 KT 120 MPH
 36H  03/0600Z 17.9N  45.7W  105 KT 120 MPH
 48H  03/1800Z 17.2N  47.9W  105 KT 120 MPH
 72H  04/1800Z 16.4N  52.2W  110 KT 125 MPH

Well, taking into account there has only been 5 recorded cases of majors east of 40W since 1851...not really a big pool to take samples from.

[TriPol]

Just now, Tatamy said:

This is a doomsday run for the NYC metro area... LOL

Serious or joke?