ATL: TROPICAL STORM BILL (03L)

[shah8]

what is a blocking pattern, what does it do in the atmosphere and to people on the ground?

[deltadog03]

http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_108l.gif

[CronkPSU]

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/images/gfs_ten_108l.gif

watch out Long Island and New England!!!

[Derek Ortt]

GFS obliterates Newfoundland

[btangy]

what is a blocking pattern, what does it do in the atmosphere and to people on the ground?

A blocking pattern forms when you have a ridge which slides to the N of a trough (known as a rex block) or two troughs at the legs of a high latitude ridge (known as an omega block... because it looks a lot like the capital greek letter omega in the 500mb height field). In both cases, the simple explanation is it's like a pileup on a freeway and causes the entire weather pattern to be very stagnant. Blocks typically form in the spring and fall. You've probably experienced one where the weather stays rotten or really nice for a week or even longer (versus the usual pattern of having storms come through every few days). Well, at least in New England, that will happen.

Blocking will prevent the trough from moving quickly toward the east coast sending Bill swiftly out to sea. The models have been trending towards a more blocked pattern (though not quite fully there yet), but like rush hour traffic building, it's slowing things down. If it verifies, this will allow Bill to come closer to Cape Cod, Maine, and Nova Scotia. The trend has continued in both the 00Z NAM and GFS, though it's much more pronounced in the NAM.

[floridasun78]

what part of wed will we see nw track?

[deltadog03]

YEs it does Derek....GFS is DEF. further West this run.

[neospaceblue]

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 7.2.3
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 19 AUG 2009 Time : 034500 UTC
Lat : 17:25:58 N Lon : 53:41:42 W


CI# /Pressure/ Vmax
7.0 / 923.1mb/140.0kt


Final T# Adj T# Raw T#
(3hr avg)
6.9 7.0 7.0

Latitude bias adjustment to MSLP : +2.1mb

Estimated radius of max. wind based on IR : 29 km

Center Temp : +11.6C Cloud Region Temp : -72.9C

Scene Type : EYE

Positioning Method : RING/SPIRAL COMBINATION

Ocean Basin : ATLANTIC
Dvorak CI > MSLP Conversion Used : ATLANTIC

Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : ON
Rapid Dissipation Flag : OFF

I wonder how strong Bill is going to be at 5 AM.

[hurricanetrack]

Wow. This is getting quite a bit more interesting. I guess odds continue to favor this missing the U.S. but geez, it gets closer with each run it seems. Almost to 70 west at 35 north yes? I am obviously looking at this very closely as IF IF IF we are going to head out and intercept Bill, that decision will have to be made as early as tomorrow evening. Another 2 degrees of longitude and things could get quite ugly for New England. What will be interesting to see is how the angle changes with time- if at all. It can come north along 72-73 west but fade east just enough to miss still. But then, Nova Scotia and points east are under fire!

[MWatkins]

FWIW the 0Z NOGAPS is way too close to the east coast of the US at t+120. That track would create some serious coastal flooding issues and have to prompt some hurricane warnings for places not familiar with such things...

https://www.fnmoc.navy.mil/wxmap_cgi/cg ... 0m&tau=120

MW

[brunota2003]

Looks like it shows at least 25 or 30 knots sustained inland.

[btangy]

00Z CMC is now showing a cut off with the trough. It lifts the northern portion of the trough away and has the center of the southern cut off over Lake Ontario. With regards to Bill, very slightly to the left and faster than the 12Z run, though it's hard to tell exactly.

Scraping Cape Cod and seacoast of Maine at 108 hrs:

http://www.weatheroffice.gc.ca/data/mod ... 12_108.jpg

Landfall between Maine/Canada border and Halifax slightly before 120hrs:

http://www.weatheroffice.gc.ca/data/mod ... 12_120.jpg

It also has a tremendous amount of rain to the left of the track because of interaction of Bill's flow with a stalled front. That could pose some serious flooding well away from the storm center.

[MWatkins]

0Z GFDL...

Code: Select all

836
WHXX04 KWBC 190520
CHGQLM
ATTENTION...NATIONAL HURRICANE CENTER

NCEP COUPLED GFDL HURRICANE MODEL FORECAST MADE FOR

HURRICANE BILL      03L

INITIAL TIME   0Z AUG 19

DISCLAIMER ...  THIS INFORMATION IS PROVIDED AS GUIDANCE.  IT
REQUIRES INTERPRETATION BY HURRICANE SPECIALISTS AND SHOULD
NOT BE CONSIDERED AS A FINAL PRODUCT.  PLEASE SEE THE TPC/NHC
OFFICIAL FORECAST.


FORECAST STORM POSITION

HOUR        LATITUDE        LONGITUDE        HEADING/SPEED(KT)

   0            16.9             52.8           295./13.0
   6            17.6             54.2           297./15.2
  12            18.3             55.6           297./14.7
  18            19.2             56.8           305./14.3
  24            20.0             58.1           303./15.0
  30            20.9             59.5           301./16.1
  36            21.8             60.8           305./15.4
  42            22.8             62.2           306./15.8
  48            23.7             63.3           311./13.4
  54            24.7             64.3           313./13.3
  60            26.0             65.2           326./15.1
  66            27.4             66.0           329./15.5
  72            28.9             66.8           332./17.0
  78            30.5             67.7           331./17.8
  84            32.1             68.4           336./17.5
  90            33.8             68.9           343./16.7
  96            35.5             68.8             3./17.9
 102            37.4             68.3            15./18.9
 108            39.4             67.1            32./22.5
 114            41.8             64.9            42./29.0
 120            44.5             61.9            49./34.3
 126            47.3             58.2            53./38.5



[thetruesms]

Man, every time I get yanked away from paying attention to the tropics is when all the interesting stuff happens

[Derek Ortt]

NCEP grib data ftp site went down about 35 minutes ago

[thetruesms]

The 00Z NAM has trended even more amplified with the trough developing in the Midwest and continues showing a split jet with a slight omega block pattern in the S stream. Highly anomalous for this time of year, but we've had some big anomalous troughs already this summer so there is recent precedent. The pattern is significantly more amplified and slower than the 12Z GFS, though the HPC is favoring the GFS longwave pattern in their model diagnostic discussion.

Oh man, that felt good to read I've been spending too much time with electrical engineers

Been trying to plot the model trends over several runs, but am having a hard time making a plot that makes much sense - too much spaghetti. Maybe I'll just make a few on separate figures, rather than trying to show them all at once.

[DreamworksSKG]

Does anyone notice two eyes? on Bill in the latest satellite loop?

what is the cause of this?

The two eyes seem to dance around each other for a bit.

is that the sign of a intense hurricane?

http://cimss.ssec.wisc.edu/tropic/real- ... mjava.html

Merged your topic with main Bill thread=cycloneye

[DreamworksSKG]

I am growing more concerned with each model run of a potential NE hit.--some of the models now have it going into the Cape. - or even a bit west. - others have it in the gulf of Maine which would still give us good wave action, rain and some wind.
The models continue to trend westward. And I still haven't seen a True Northern turn yet on the Satellite. The eyewall seems to be going through regenration as the storm intensifies. with a double eyes for awhile overnight - In the last frame it looks like the storm is moving more west than northwest. - closer toward the NE Islands of the Lesser Antillies.

I am wondering with a Cat 4 hurricane less than 200 miles off the NE coast of the US Virgin Islands and Lesser Antillies, and Puerto Rico shoudln't they at least issue a tropical storm Watch or hurricane watch?

And in a few days if it gets close enough to New England shouldn't they at least issue a Hurricane Watch?

[brunota2003]

That is something wrong with the particular loop that is running...look at this image:

http://www.ssd.noaa.gov/goes/flt/t2/loop-vis.html

No overlaps of images there.

[HurricaneBill]

If Bill makes a destructive hit somewhere, will I be banned?