ATL: SANDY - Models

[CrazyC83]

http://moe.met.fsu.edu/cyclonephase/gfs ... dswath.png

Even if the sustained winds aren't that high away from the coast, that is only a few hundred feet above the surface. Areas that see downsloping and funnelling could easily see extreme gusts.

And I am in the northernmost area of green - so that is winds over 65 kt (appears to be 70 kt per soundings) at 925mb, less than 1,000 feet above the surface.

[HurrMark]

[img ]http://moe.met.fsu.edu/cyclonephase/gfs/fcst/archive/12102606/6.windswath.png[/img ]

Even if the sustained winds aren't that high away from the coast, that is only a few hundred feet above the surface. Areas that see downsloping and funnelling could easily see extreme gusts.

And I am in the northernmost area of green - so that is winds over 65 kt (appears to be 70 kt per soundings) at 925mb, less than 1,000 feet above the surface.

Hmmm...according to this, Boston, coastal Maine and the Cape would have the worst winds. That's why New England should not be complacent even if this "hits" the mid-Atlantic.

[CrazyC83]

[img ]http://moe.met.fsu.edu/cyclonephase/gfs/fcst/archive/12102606/6.windswath.png[/img ]

Even if the sustained winds aren't that high away from the coast, that is only a few hundred feet above the surface. Areas that see downsloping and funnelling could easily see extreme gusts.

And I am in the northernmost area of green - so that is winds over 65 kt (appears to be 70 kt per soundings) at 925mb, less than 1,000 feet above the surface.

Hmmm...according to this, Boston, coastal Maine and the Cape would have the worst winds. That's why New England should not be complacent even if this "hits" the mid-Atlantic.

Exactly, likewise a New England hit would be huge all the way to Virginia.

[CrazyC83]

Here is the re-uploaded GFS wind map. This is at 925mb so not far above the surface.

[GCANE]

Interesting SREF run

500mb continues to dig well into Maryland with a heck-of-a tilt to the SE.

http://www.spc.noaa.gov/exper/sref/index.php

Once surface low goes on-shore, another redevelops behind it.

http://www.spc.noaa.gov/exper/sref/cmm_ ... L_MEAN_SD_

[Hybridstorm_November2001]

Here is the re-uploaded GFS wind map. This is at 925mb so not far above the surface.

Are those winds sustained, or gusts?

[CrazyC83]

Here is the re-uploaded GFS wind map. This is at 925mb so not far above the surface.

Are those winds sustained, or gusts?

Sustained at the 925mb level.

[clifman]

The 18Z GFDL has Sandy hooking around Cape Hatteras, and North Carolina then going over the DelMarVA peninsula inland... at 929mb.

http://raleighwx.americanwx.com/models/ ... lLoop.html

The regional models are probably not very reliable in this situation.

For us newbies, can you explain why regional models are likely not reliable here? Thanks!

[CrazyC83]

The 18Z GFDL has Sandy hooking around Cape Hatteras, and North Carolina then going over the DelMarVA peninsula inland... at 929mb.

http://raleighwx.americanwx.com/models/ ... lLoop.html

The regional models are probably not very reliable in this situation.

For us newbies, can you explain why regional models are likely not reliable here? Thanks!

They don't handle extratropical transition very well. They are most reliable in the deep tropics.

[GCANE]

Interesting SREF run

500mb continues to dig well into Maryland with a heck-of-a tilt to the SE.

http://www.spc.noaa.gov/exper/sref/index.php

Once surface low goes on-shore, another redevelops behind it.

http://www.spc.noaa.gov/exper/sref/cmm_ ... L_MEAN_SD_

SREF also showing the development of a strong and large "warm anomaly" at 500mb as Sandy approaches the coast.

http://www.spc.noaa.gov/exper/sref/sref ... _MEAN_SD__

All the way down to 850mb

http://www.spc.noaa.gov/exper/sref/sref ... _MEAN_SD__

[Hybridstorm_November2001]

Here is the re-uploaded GFS wind map. This is at 925mb so not far above the surface.

Are those winds sustained, or gusts?

Sustained at the 925mb level.

Thanks, so not that far above the 1000 mb (or surface level) frightening. I wonder how much mixing down there might be? I guess that is the million or rather billion dollar question, huh.

[CrazyC83]

Thanks, so not that far above the 1000 mb (or surface level) frightening. I wonder how much mixing down there might be? I guess that is the million or rather billion dollar question, huh.

Even with a Mid-Atlantic landfall, the Cape Cod and Islands region could see the highest sustained winds. Far eastern Long Island is another area that could see such.

[sicktght311]

Just put this graphic together quickly of the 12z GFS run. Wow....wow....that right wide arc, and then that hard left hook and loop. Devastating
http://imageshack.us/photo/my-images/233/gfs12z.jpg

[GCANE]

Just put this graphic together quickly of the 12z GFS run. Wow....wow....that right wide arc, and then that hard left hook and loop. Devastating
http://imageshack.us/photo/my-images/233/gfs12z.jpg

Unlike yesterday, it is not swinging out as much east of the Gulf Stream.

http://rammb.cira.colostate.edu/product ... 260600.GIF

[GCANE]

06Z GFS is showing transition back to a symmetric warm core at some point.

http://moe.met.fsu.edu/cyclonephase/gfs ... phase1.png

Waiting to see what the 12Z run shows.

[tolakram]

12Z GFS saved images. Now showing Long Island hit

[CrazyC83]

So a see-saw again. Still no closer to the answer. A bit too far north IMO, but not that it matters really.

[tolakram]

Met Question.

Can Virtual Temp or the Theta-E plots be used to predict warm or cold core?

Prior to northwest turn:


Temps fall off rapidly as it gets close to shore.


Theta-E

[HurrMark]

Looks a Ct. hit to me after probably going over eastern LI...but all in all, not much of a change from 00Z. I know it hasn't been historically as consistent as the Euro since this storm formed... but GFS has been quite consistent the last 24-36 hours.

[CrazyC83]

Question on wind to surface in gusts?

If the winds aloft (18Z Tuesday forecast) are 95 kt at 850mb and 80 kt at 925mb, what would that translate into at the surface? I live in an area prone to valley funnelling from the east, which would be the wind direction.

My estimate is sustained 35-50 mph with gusts 65-80 mph.