Tropical Storm GABRIELLE (ATL): Global & BAM Models

[LarryWx]

I can now add the 12Z UKMET (74.1 W...thanks Luis) and 12Z Euro (~73 W) to the list of too far west initializations vs. the actual of ~71.5 W. Surprise, surprise, they both hit SC. That tells me that these, too, are very likely moving the storm too far west into the US.

Here is my updated list for the 12Z Wed models:

1) Too far west initializations: ECMWF, UKMET, Canadian, NOGAPS. All of these hit in the interval of ~Savannah to Myrtle Beach.

2) Good initializations: GFS/GFDL. These both miss SC/GA.

The very clear model pattern continues to tell me NC (IF any SE state is directy hit) heavily favored over SC/GA/FL as of now.

[cycloneye]

CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1847 UTC WED SEP 5 2007

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

DISTURBANCE INVEST (AL992007) 20070905 1800 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
070905 1800 070906 0600 070906 1800 070907 0600

LAT LON LAT LON LAT LON LAT LON
BAMS 29.3N 70.5W 29.4N 70.0W 29.6N 70.1W 30.0N 70.9W
BAMD 29.3N 70.5W 30.3N 68.9W 31.4N 68.4W 32.1N 69.0W
BAMM 29.3N 70.5W 29.6N 69.5W 30.0N 69.7W 30.4N 70.7W
LBAR 29.3N 70.5W 29.6N 68.7W 30.2N 67.2W 31.1N 65.2W
SHIP 30KTS 37KTS 46KTS 52KTS
DSHP 30KTS 37KTS 46KTS 52KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
070907 1800 070908 1800 070909 1800 070910 1800

LAT LON LAT LON LAT LON LAT LON
BAMS 31.0N 72.2W 33.9N 74.2W 36.7N 72.8W 37.0N 68.5W
BAMD 33.1N 70.5W 36.2N 73.4W 40.4N 71.5W 42.6N 63.4W
BAMM 31.3N 72.2W 34.2N 74.8W 37.3N 73.5W 37.6N 67.6W
LBAR 31.8N 63.1W 33.4N 58.6W 33.5N 52.2W 34.5N 40.2W
SHIP 61KTS 70KTS 69KTS 62KTS
DSHP 61KTS 70KTS 69KTS 62KTS

...INITIAL CONDITIONS...
LATCUR = 29.3N LONCUR = 70.5W DIRCUR = 90DEG SPDCUR = 9KT
LATM12 = 29.2N LONM12 = 72.5W DIRM12 = 96DEG SPDM12 = 9KT
LATM24 = 29.3N LONM24 = 74.3W
WNDCUR = 30KT RMAXWD = 40NM WNDM12 = 25KT
CENPRS = 1004MB OUTPRS = 1013MB OUTRAD = 200NM SDEPTH = M
RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM

30 kts,1004 mbs.

[ronjon]

Interesting Discussion from HPC on synoptic setup and models.

MODEL DIAGNOSTIC DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER

DEVELOPING CYCLONE OFF THE SOUTHEAST COAST...

THE NAM IS FURTHER TO THE S AND W THAN THE GFS THRU MUCH OF THE
PERIOD AND IS AROUND 25 MB DEEPER AT THE SFC BY THE END OF DAY 2.
THE 00Z ECMWF/12Z CMC/UKMET GLOBAL ARE FASTER THAN THE NAM TO
CARRY THE SYSTEM WWD...BUT THE ECMWF SOLUTION IS DISCOUNTED GIVEN
THAT ITS 12HR FORECAST SHOWED A POSITION WELL WEST OF WHAT WAS
OBSERVED AT 12Z...WHILE THE CMC/UKMET INITIALIZED THE SYSTEM TOO
FAR W AS WELL. GIVEN THE POOR INITIALIZATIONS OF THE MODELS...DO
NOT HAVE A GREAT DEAL OF CONFIDENCE IN ANY PARTICULAR
SOLUTION...

BUT IN COMPARISON TO THE REMAINING MODELS THE GFS
APPEARS TOO WEAK WITH THE MID LVL RIDGE TO THE N OF THE SYSTEM AND
IS THEREFORE TOO SLOW TO MOVE THE SYSTEM WWD...WHILE ALLOWING THE
SYSTEM TO MOVE TOO FAR TO THE N. A MORE PROGRESSIVE/AMPLIFIED/SLY
SOLUTION THAN THE GFS WOULD BETTER FIT THE MODEL CONSENSUS. NOT
READY TO BUY INTO A SOLUTION AS PROGRESSIVE AS THE ECMWF GIVEN ITS
POOR FORECAST OR THE CMC/UKMET GIVEN THEIR POOR INITIALIZATIONS.

NOT SURE A SYSTEM AS DEEP AS THE NAM IS IN ORDER EITHER GIVEN ITS
TENDENCY TO OVER-AMPLIFY ANY SYSTEM OF A TROPICAL NATURE. THAT
SAID...THE CURRENT HPC/TPC THINKING IS FOR A TRACK FURTHER TO S
AND DEEPER THAN THE GFS...BUT NOT QUITE AS PROGRESSIVE AS THE CMC
GLOBAL/UKMET/00Z ECMWF.

THERE ARE ALSO ISSUES WITH THE STRENGTH/WRN EXTENT
OF THE MID LVL RIDGE OVER THE WRN ATLC AND ERN/SERN CONUS.
TELECONNECTION-FAVORED UPSTREAM CONFIGURATION FAVORS A HEALTHY
SERN RIDGE CLOSER TO WHAT IS DEPICTED IN THE ECMWF/RECENT NCEP
MEANS/06Z-12Z GFS. GUIDANCE CONTINUES TO SHOW THE POTENTIAL FOR
LOW PRESSURE OFF THE SERN COAST TO DEVELOP AND LIFT NWD ALONG THE
EAST COAST. THE 12Z GFS HAS SHIFTED NOTICEABLY WWD TOWARD THE
DOMINANT CLUSTER OF OTHER MODEL GUIDANCE.

[Derek Ortt]

the recon pressure is almost equal the GFDL 6 hour forecast from 12Z

This may not do ANYTHING for another 24 hours, then start to develop fairly quickly

[Brent]

the recon pressure is almost equal the GFDL 6 hour forecast from 12Z

This may not do ANYTHING for another 24 hours, then start to develop fairly quickly

Oh yay... another day of "storm cancel" and "it looks dead" posts. Joy.

[Derek Ortt]

I wish some of the "it's dead" posters would join the hurricane futures market

I'd be more than happy to take their $$

[LarryWx]

Interesting Discussion from HPC on synoptic setup and models.

MODEL DIAGNOSTIC DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER

DEVELOPING CYCLONE OFF THE SOUTHEAST COAST...

THE 00Z ECMWF/12Z CMC/UKMET GLOBAL ARE FASTER THAN THE NAM TO
CARRY THE SYSTEM WWD...BUT THE ECMWF SOLUTION IS DISCOUNTED GIVEN
THAT ITS 12HR FORECAST SHOWED A POSITION WELL WEST OF WHAT WAS
OBSERVED AT 12Z...WHILE THE CMC/UKMET INITIALIZED THE SYSTEM TOO
FAR W AS WELL.

NOT READY TO BUY INTO A SOLUTION AS PROGRESSIVE AS THE ECMWF GIVEN ITS
POOR FORECAST OR THE CMC/UKMET GIVEN THEIR POOR INITIALIZATIONS.

NOT SURE A SYSTEM AS DEEP AS THE NAM IS IN ORDER EITHER GIVEN ITS
TENDENCY TO OVER-AMPLIFY ANY SYSTEM OF A TROPICAL NATURE. THAT
SAID...THE CURRENT HPC/TPC THINKING IS FOR A TRACK FURTHER TO S
AND DEEPER THAN THE GFS...BUT NOT QUITE AS PROGRESSIVE AS THE CMC
GLOBAL/UKMET/00Z ECMWF.

HPC is on the ball as far as I'm concerned!

[Typhoon_Willie]

So would I for that matter! Do to their short sighted ways I would like to get their money as well!

[cpdaman]

we just need to set up pay pal w/ a link to the hurricane future's option's and dervivatives

hmmm.....

larry as you stated and i replied earlier there is the possibility that (num 1) can make even a strong number 2 a moot point.

the biggest threat extends from the carolina's northward (including south carolina) IMO

[Meso]

The 18z NAM

[cycloneye]

84 hours

The 18z GFS run shows a little more right track.Gets close to Cape Hatteras but does not get to land.

90 hours

[cycloneye]

I forgot to post the initial position.The 18z run of GFS initial position is very good,as it is located very close to where the actual low is.

6 hours

[miamicanes177]

Code: Select all

623
WHXX04 KWBC 052324
CHGQLM
ATTENTION...NATIONAL HURRICANE CENTER

NCEP COUPLED GFDL HURRICANE MODEL FORECAST MADE FOR

TROPICAL DEPRESSION INVEST    99L

INITIAL TIME  18Z SEP  5

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            29.2             70.5            90./ 8.9
   6            29.4             69.6            81./ 8.2
  12            29.6             68.7            73./ 7.7
  18            29.9             68.5            40./ 4.0
  24            30.0             68.5           336./  .9
  30            29.9             69.3           261./ 6.7
  36            29.8             70.3           264./ 8.8
  42            29.8             71.3           269./ 9.3
  48            29.9             72.5           277./10.0
  54            30.3             73.6           290./10.0
  60            30.6             74.6           283./ 9.5
  66            31.1             75.4           304./ 8.5
  72            31.5             76.2           296./ 7.5
  78            32.1             76.4           337./ 7.0
  84            32.8             76.9           322./ 7.8
  90            33.3             76.8            17./ 5.7
  96            34.1             76.3            33./ 8.6
 102            34.8             75.7            42./ 8.8
 108            35.5             74.8            50./10.4
 114            36.1             73.8            61./ 9.1
 120            36.6             72.7            65./10.5
 126            36.9             71.5            75./ 9.9


[cycloneye]

18z GFDL initial plot is more to the east than in the 12z run.Clips Cape Hatteras and then after going over outerbanks it goes out to sea.

[vacanechaser]

84 hours

The 18z GFS run shows a little more right track.Gets close to Cape Hatteras but does not get to land.

90 hours

maybe so, however, the gfs has had a problem in the past and even recently with not showing the ridge strong enough... has always had that problem and from the recent events with dea and felix, in the early runs it wanted to do the same, weaker ridge..


Jesse V. Bass III
http://www.vastormphoto.com
Hurricane Intercept Research Team

[MCorder]

Ok, the 12Z GFDL (along with a few others) from yesterday had it going up the east coast over the Hampton Roads area (VA Beach), the 18Z kicks it off Hatters, with the warm current.
Today the same pattern occurred at the same times. Is this normal with tropical system modeling or just something I happened to notice? Maybe I've just been to far north for too long...

Todays 12Z:
http://moe.met.fsu.edu/cgi-bin/gfdltc2. ... =Animation
Yesterdays 12Z:
http://moe.met.fsu.edu/cgi-bin/gfdltc2. ... =Animation
Todays 18Z:
http://moe.met.fsu.edu/cgi-bin/gfdltc2. ... =Animation
Yesterdays 18Z:
http://moe.met.fsu.edu/cgi-bin/gfdltc2. ... =Animation


Thanks
MCorder
Kodiak Alaska

[Stephanie]

It's interesting that you would point those out.

This is from the "All About Models" in our Reference forum;

2. Be Suspicious of Big Changes in the 6Z or 18Z Guidance Remember that the global models almost never get new data for the 6Z and 18Z runs, which means these models are rerun using 12 hour old data. This is also why we almost never see huge changes to the 11AM and 11PM EDT forecast tracks from the NHC if the models start to shift…they almost always wait until new data gets in at the 0Z and 12Z runs. Don’t get too excited about a shift until it’s confirmed by the full runs of the models.

Now, with that in mind, it seems to me that the model has been consistant over the past few days bringing the storm more to the west with newer data, as compared to the 18Z runs.

Hmmm...

[brunota2003]

Ahhh...Who is putting up the 00Z GFS? If its started yet...

[GeneratorPower]

Cycloneye will do it. That's how he keeps his post counts up.

What are you up to now, Luis? 45,000?

[brunota2003]

Cycloneye will do it. That's how he keeps his post counts up.

What are you up to now, Luis? 45,000?

48,291 and counting...