ATL: BERTHA - Models

[TheStormExpert]

:uarrow: I wonder if such a dramatic right hook is an indication of getting trapped under high pressure and/or loop?

Exactly! First storm that comes to mind is Jeanne(2004).

[NDG]

0z GFS joins the euro of Bertha strengthening north of the Greater Antilles as she recurves out to sea.

[NDG]

0z HWRF is a bit stronger than its last few runs.

[meriland23]

What do you personally think the chances are this hits the US somewhere on the EC...

[somethingfunny]

I can't take any of these intensity models seriously as long as Hispaniola is in the projected path.

I can't really take any of the track models post-Hispaniola too seriously either since a severely disrupted storm would probably just drift westward afterward and have to run a reboot cycle.

[NDG]

06z models

[SeGaBob]

So do any computer models show the no recurve (or at least delayed) scenario anymore?

[tolakram]

So do any computer models show the no recurve (or at least delayed) scenario anymore?

None that I know of.

[gatorcane]

From what I am seeing from the computer models, Bertha is able to round the western periphery of the Bermuda High ridge before that ridge can build westward over the SW Atlantic. Once she gets ejected off to the NE, that ridge does build in though. So because of her fast forward speed, it looks like she is going to find the escape route. If she were a couple of days slower clearing the islands, she probably would get blocked in the Bahamas.

The models are actually in good agreement on a recurve. There are several GFS ensemble members that bring her a bit more west into the Southern Bahamas without a recurve but those are likely keeping her an open wave and seem like outliers right now.

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[SeGaBob]

Thanks gatorcane... I figured it would find an escape route one way or another.

[Airboy]

From what I am seeing from the computer models, Bertha is able to round the western periphery of the Bermuda High ridge before that ridge can build westward over the SW Atlantic. Once she gets ejected off to the NE, that ridge does build in though. So because of her fast forward speed, it looks like she is going to find the escape route. If she were a couple of days slower clearing the islands, she probably would get blocked in the Bahamas.

The models are actually in good agreement on a recurve. There are several GFS ensemble members that bring her a bit more west into the Southern Bahamas without a recurve but those are likely keeping her an open wave and seem like outliers right now.

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

Could a stronger system mean a slower system that would allowed the ridge to build more before Bertha arrives and can move around it and force it moving more west or do the strength and size don't matter to the speed of the system?

[Dean4Storms]

From what I am seeing from the computer models, Bertha is able to round the western periphery of the Bermuda High ridge before that ridge can build westward over the SW Atlantic. Once she gets ejected off to the NE, that ridge does build in though. So because of her fast forward speed, it looks like she is going to find the escape route. If she were a couple of days slower clearing the islands, she probably would get blocked in the Bahamas.

The models are actually in good agreement on a recurve. There are several GFS ensemble members that bring her a bit more west into the Southern Bahamas without a recurve but those are likely keeping her an open wave and seem like outliers right now.

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

Could a stronger system mean a slower system that would allowed the ridge to build more before Bertha arrives and can move around it and force it moving more west or do the strength and size don't matter to the speed of the system?

No, a Stronger system feels the break in the ridge even moreso steered entirely by the mid level flow. A much weaker system could get steered more westerly not influenced as much by the mid levels.

[blp]

I can't take any of these intensity models seriously as long as Hispaniola is in the projected path.

I can't really take any of the track models post-Hispaniola too seriously either since a severely disrupted storm would probably just drift westward afterward and have to run a reboot cycle.

You bring up a great point. Land interaction is the great unknown here. And that NHC track is very very close to Hispaniola.

[cycloneye]

CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS NATIONAL HURRICANE CENTER MIAMI FL
1831 UTC FRI AUG 1 2014

DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.
PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE
AND SUBTROPICAL CYCLONE INFORMATION.

ATLANTIC OBJECTIVE AIDS FOR

TROPICAL CYCLONE BERTHA (AL032014) 20140801 1800 UTC

...00 HRS... ...12 HRS... ...24 HRS... ...36 HRS...
140801 1800 140802 0600 140802 1800 140803 0600

LAT LON LAT LON LAT LON LAT LON
BAMS 14.5N 60.3W 16.0N 63.7W 17.7N 67.2W 19.4N 70.4W
BAMD 14.5N 60.3W 15.8N 62.6W 17.3N 65.0W 19.1N 67.8W
BAMM 14.5N 60.3W 15.7N 63.1W 17.3N 66.0W 19.0N 68.9W
LBAR 14.5N 60.3W 16.1N 63.2W 17.9N 66.3W 19.9N 69.4W
SHIP 45KTS 45KTS 47KTS 48KTS
DSHP 45KTS 45KTS 47KTS 48KTS

...48 HRS... ...72 HRS... ...96 HRS... ..120 HRS...
140803 1800 140804 1800 140805 1800 140806 1800

LAT LON LAT LON LAT LON LAT LON
BAMS 21.1N 73.2W 24.3N 76.7W 27.3N 77.1W 30.1N 75.2W
BAMD 20.9N 70.5W 24.5N 74.4W 28.3N 74.5W 32.6N 68.9W
BAMM 21.0N 71.7W 24.7N 75.1W 28.2N 74.4W 31.3N 69.6W
LBAR 22.3N 71.9W 27.4N 74.0W 32.4N 71.0W 34.9N 63.9W
SHIP 51KTS 62KTS 72KTS 75KTS
DSHP 51KTS 62KTS 72KTS 75KTS

...INITIAL CONDITIONS...
LATCUR = 14.5N LONCUR = 60.3W DIRCUR = 295DEG SPDCUR = 21KT
LATM12 = 12.9N LONM12 = 56.1W DIRM12 = 295DEG SPDM12 = 18KT
LATM24 = 11.5N LONM24 = 53.1W
WNDCUR = 45KT RMAXWD = 30NM WNDM12 = 40KT
CENPRS = 1007MB OUTPRS = 1012MB OUTRAD = 100NM SDEPTH = M
RD34NE = 100NM RD34SE = 40NM RD34SW = 0NM RD34NW = 40NM

[gatorcane]

18Z models - a little less clustered in the Bahamas than the 12Z and a bit of west shift through still well offshore the SE US. Interestingly the CMC, which has had a right-bias this whole week is the left-most model:



12Z models:

[CrazyC83]

How does this setup differ from Irene 2011, which had a similar initial setting? Stronger trough?

[blp]

FWIW the 00z GFS now brings Bertha on a direct hit over the heart of Hispaniola causing a bit of a westward shift and now recurve happens in central Bahamas.

[blp]

Saw this on another board the Nasa model has a possible visit with Florida. I don't know how reliable this is but it is interesting.

[Hurricane Alexis]

Saw this on another board the Nasa model has a possible visit with Florida. I don't know how reliable this is but it is interesting.

Ditto that. Though I've never heard or seen a met cite that model as a source for a forecast.

[gatorcane]

12Z Guidance, the BAMs keep slowly shifting westward. the HWRF is also almost as west as the BAMs: