ATL: Ex-DANIELLE - Models

[CalmBeforeStorm]

http://www.nhc.noaa.gov/verification/verify6.shtml

http://www.nhc.noaa.gov/verification/verify5.shtml

Please keep in mind that the average NHC error at 120 hours is 250-300 miles over the last 5 years and the average model error at 48 hours last year was about 100 miles. That's not to say that these early forecasts have not established a mean for which errors will occurs off of and that the errors might occur to the left or the right of the current forecasts. Just the same, imagine Danielle in a position 300 miles to the south of it's forecast 5 day position and tell me if you think it would then be a certain recurve.
We must just wait because technology is simply not good enough to produce accurate forecasts in the long term yet.

[CalmBeforeStorm]

The logic still hasn't changed though, a massive high is still going to move off of the east coast. The reason why models curve it east is because they turn it too far north to feel the building ridge and head back west. I wouldn't be surprised to see more shifting tonight and tomorrow.

That massive high is even a longer range forecast then the recurve in response to the trough and is even more dubious of a prediction.

[KWT]

Yeah thats true Rock though I think if you look at the current presentation, you'd certainly have to think its going to strengthen faster then just moderate strengthening!

Still thats why you can't ever rule out things like that for sure!

I just think it makes logical sense that a stronger system will curve up and latch onto the troughing, whilst if its weaker then it may well not make it.

One thing I will say, I doubt the models have done shifting, I personally think they will go back west again at least somewhat...

[ronjon]

Starting to see some real separation between the HWRF and GFDL at 5 days - a full 3 deg longitude with GFDL at 28N-55W and HWRF at 28N-58W. I noticed that the HWRF builds slightly stronger ridging to its north and the GFDL leaves a weakness along the east coast from the mid-atlantic low. Probably not surprising that the GFDL is that far east since its run off the GFS. Awaiting the 00Z Globals to see if anymore light is shed on the upper air pattern.

[gatorcane]

Yeah thats true Rock though I think if you look at the current presentation, you'd certainly have to think its going to strengthen faster then just moderate strengthening!

Still thats why you can't ever rule out things like that for sure!

I just think it makes logical sense that a stronger system will curve up and latch onto the troughing, whilst if its weaker then it may well not make it.

One thing I will say, I doubt the models have done shifting, I personally think they will go back west again at least somewhat...

Yes but are you sure the models are handling the dry air proprerly? Would not be surprised if we only see modest strengthening especially as it gets closer to the ull off to the nw

[CalmBeforeStorm]

One thing I will say, I doubt the models have done shifting, I personally think they will go back west again at least somewhat...

That's the truest statement you've made. It's a almost a certainty they will shift. The only absolute is that there are no absolutes.

[KWT]

Starting to see some real separation between the HWRF and GFDL at 5 days - a full 3 deg longitude with GFDL at 28N-55W and HWRF at 28N-58W. I noticed that the HWRF builds slightly stronger ridging to its north and the GFDL leaves a weakness along the east coast from the mid-atlantic low. Probably not surprising that the GFDL is that far east since its run off the GFS. Awaiting the 00Z Globals to see if anymore light is shed on the upper air pattern.

I think also the fact that the GFDL is a good 15-20kts stronger then the HWRF in the first part of the run probably helps the system to gain more latitude earlier on and thus feel the upper trough sooner.

No doubts though the HWRF is actually a fairly large change in terms of what it progs, whilst synoptically its not too different, the fact that the system stays on a NW track rather then bends back WNW/W is pretty important.

00z will be interesting for sure!!!

[supercane]

SFWMD graphic updated, but can't find text:

[gatorcane]

Looking at the latest models above I still feel pretty good about things especially here in southern Florida. I doubt we will have to deal with Danielle here. Thank you conus trough

[KWT]

Every single model now suggests a recurve...not a single ensemble member suggests a US threat either from the GFS and the ECM ensemble is now in better agreement further east.

To be honest not much of an arguement for a threat now, though as said before things can and quite probably will change, and for Bermuda that could make a real difference down the road.

[bob rulz]

I think if this were to threaten the U.S. it would be most likely to be a New England threat. It's still far too early to know for sure what will happen - I don't take much stock in models that far out unless they're remarkably consistent for a long period of time.

[gatorcane]

Every single model now suggests a recurve...not a single ensemble member suggests a US threat either from the GFS and the ECM ensemble is now in better agreement further east.

To be honest not much of an arguement for a threat now, though as said before things can and quite probably will change, and for Bermuda that could make a real difference down the road.

Agreed kwt very low chance of a us threat here especially the se us. All models deflect it away.

Models may shift some but you very likely won't see them all shift to Florida I am pretty confident about that. Not a Frances this time around too much troughiness

[CrazyC83]

If anywhere is threatened, it would most likely be Bermuda and Atlantic Canada.

[KWT]

Agreed kwt very low chance of a us threat here especially the se us. All models deflect it away.

Models may shift some but you very likely won't see them all shift to Florida I am pretty confident about that. Not a Frances this time around too much troughiness

Its not so much even the fact that they deflect it away thats noteable, its just how far east of the states it occurs, I mean most models are still between 55-60W and it'd have to go way westwards of all the models to become a threat...

Now Bermuda is a different story totally, thats well within the margin for model error still IMO...

[Vortex]

agreed, I think the recurve is nearly a given now..

[rockyman]

Just a little history...Here was the 120 hour forecast for Frances from Advisory Number 2 (when it was near the position and strength of Danielle):
120HR VT 30/0600Z 22.0N 54.0W 70 KT

In actuality, Frances did not reach 22.0N until 71W
INITIAL 01/2100Z 22.0N 71.0W 120 KT

That's an error of 17 degrees longitude.

If Danielle had the same error, it would cross 22N at around 70N (near the Turks & Caicos).

[ROCK]

The NAM which is useless in the tropics shows the progression of the trof as it lifts out at 84 and a nice 1024 high into the central US expanding eastward.....FWIW...

[jimvb]

Did you notice? The 2010 Aug 22 18Z run shows Danielle curving out to sea well east of Bermuda. But it also shows a hurricane suddenly blossoming in the GOM about Sept 6, striking Florida in a rare place - Cedar Key, crossing over to the Atlantic coast as a major hurricane going up the Georgia and South Carolina coasts and the Outer Banks. The question is whether this upstart model storm will make it to the 00Z run tonight.

[cycloneye]

00z Tropical Models

They came out late. SHIP has a hurricane in 36 hours.

Code: Select all

WHXX01 KWBC 230122
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0122 UTC MON AUG 23 2010
 
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 DANIELLE (AL062010) 20100823 0000 UTC
 
        ...00 HRS...   ...12 HRS...   ...24 HRS. ..   ...36 HRS...
        100823  0000   100823  1200   100824  0000   100824  1200
 
         LAT    LON     LAT    LON     LAT    LON     LAT    LON
BAMS    14.0N  35.3W   15.1N  37.0W   16.5N  39.6W   18.3N  42.9W
BAMD    14.0N  35.3W   15.0N  37.4W   16.2N  39.8W   17.7N  42.2W
BAMM    14.0N  35.3W   15.1N  37.3W   16.4N  39.9W   18.0N  42.9W
LBAR    14.0N  35.3W   15.0N  37.5W   16.3N  40.5W   17.5N  43.5W
SHIP        40KTS          48KTS          57KTS          65KTS
DSHP        40KTS          48KTS          57KTS          65KTS
 
        ...48 HRS...   ...72 HRS...   ...96 HRS. ..   ..120 HRS...
        100825  0000   100826  0000   100827  0000   100828  0000
 
         LAT    LON     LAT    LON     LAT    LON     LAT    LON
BAMS    20.1N  46.2W   22.6N  52.3W   23.8N  53.4W   28.1N  52.0W
BAMD    19.5N  44.6W   23.9N  49.2W   28.0N  51.8W   31.2N  53.8W
BAMM    19.7N  45.9W   22.9N  51.0W   25.3N  52.6W   29.0N  52.4W
LBAR    19.0N  46.7W   22.6N  51.8W   27.4N  53.5W   31.4N  53.3W
SHIP        72KTS          82KTS          86KTS          84KTS
DSHP        72KTS          82KTS          86KTS          84KTS
 
         ...INITIAL CONDITIONS...
LATCUR =  14.0N LONCUR =  35.3W DIRCUR = 315DEG SPDCUR =  11KT
LATM12 =  12.2N LONM12 =  33.9W DIRM12 = 314DEG SPDM12 =  11KT
LATM24 =  11.2N LONM24 =  32.3W
WNDCUR =   40KT RMAXWD =   45NM WNDM12 =   30KT
CENPRS = 1003MB OUTPRS = 1012MB OUTRAD =  220NM SDEPTH =   S
RD34NE =   30NM RD34SE =   30NM RD34SW =   45NM RD34NW =  45NM


[gatorcane]

Just a little history...Here was the 120 hour forecast for Frances from Advisory Number 2 (when it was near the position and strength of Danielle):
120HR VT 30/0600Z 22.0N 54.0W 70 KT

In actuality, Frances did not reach 22.0N until 71W
INITIAL 01/2100Z 22.0N 71.0W 120 KT

That's an error of 17 degrees longitude.

If Danielle had the same error, it would cross 22N at around 70N (near the Turks & Caicos).

Right but by this time we had a couple of models bending her to the left towards the Bahamas and Florida. This time around all are taking her on a recurve path. This won't be a Frances situation.