ATL Tropical Depression GUSTAV - Model Runs

[Scorpion]

Looks troublesome for Jamaica. They've had bad luck with canes these past few years...

Not really, as they really could have been nearly wiped out twice in 5 years but were spared by last minute wobbles.

[artist]

A lot of the models has this reaching hurricane force by the end of thier runs, a few have this close to cat-3 and one has it bordering cat-4 strength from what I've seen...those higher strength runs are certainly possible if it can avoid Hispaniola.

My greatest strength comes from knowing many models had Fay that strong as well!

[cycloneye]

GFDL did a 180 from a cat 3 to nothing in this 18z GFDL run:

124
WHXX04 KWBC 222327
CHGQLM
ATTENTION...NATIONAL HURRICANE CENTER

NCEP COUPLED GFDL HURRICANE MODEL FORECAST MADE FOR

TROPICAL DEPRESSION INVEST 94L

INITIAL TIME 18Z AUG 22

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 10.9 56.0 275./14.9

STORM DISSIPATED AT 0 HRS AT THE ABOVE PSN.

[cycloneye]

Moving more slowly at 9kts.

WHXX01 KWBC 230050
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0050 UTC SAT AUG 23 2008

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 (AL942008) 20080823 0000 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
080823 0000 080823 1200 080824 0000 080824 1200

LAT LON LAT LON LAT LON LAT LON
BAMS 10.9N 54.5W 12.0N 57.3W 13.4N 59.8W 14.9N 62.3W
BAMD 10.9N 54.5W 11.8N 57.3W 12.8N 60.2W 13.8N 62.8W
BAMM 10.9N 54.5W 11.8N 57.5W 13.2N 60.3W 14.4N 62.9W
LBAR 10.9N 54.5W 11.7N 57.1W 12.8N 60.0W 14.0N 62.8W
SHIP 25KTS 28KTS 33KTS 41KTS
DSHP 25KTS 28KTS 33KTS 41KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
080825 0000 080826 0000 080827 0000 080828 0000

LAT LON LAT LON LAT LON LAT LON
BAMS 16.0N 64.4W 18.0N 69.1W 19.4N 73.1W 19.6N 77.4W
BAMD 15.0N 65.3W 17.0N 69.2W 17.6N 72.4W 16.9N 76.4W
BAMM 15.6N 65.4W 17.5N 69.6W 18.6N 73.3W 18.3N 77.3W
LBAR 15.2N 65.5W 17.0N 69.7W 17.5N 73.1W 16.4N 76.0W
SHIP 52KTS 67KTS 75KTS 81KTS
DSHP 52KTS 67KTS 56KTS 53KTS

...INITIAL CONDITIONS...
LATCUR = 10.9N LONCUR = 54.5W DIRCUR = 285DEG SPDCUR = 9KT
LATM12 = 10.4N LONM12 = 52.7W DIRM12 = 260DEG SPDM12 = 11KT
LATM24 = 11.6N LONM24 = 50.0W
WNDCUR = 25KT RMAXWD = 60NM WNDM12 = 30KT
CENPRS = 1008MB OUTPRS = 1010MB OUTRAD = 120NM SDEPTH = M
RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM

[Derek Ortt]

looks like nothing was really inserted into the model as it starts as dissipated

[TreasureIslandFLGal]

This one concerns me. Talk of a major developing and a deep digging trough near the end of the runs makes it sound like an eastern side of the GOM set up if it get in there at all.

Maybe it won't get its act together though and instead stay more westerly, missing the connection altogether next week.

I know, I know...way too early to talk about this at all.

[cycloneye]

It appears almost a free ride from strong shear according to the latest 00:00 UTC SHIP forecast.

Code: Select all

         *   ATLANTIC SHIPS INTENSITY FORECAST       *
                    *        GOES/OHC INPUT INCLUDED            *
                    *      INVEST  AL942008  08/23/08  00 UTC   *

TIME (HR)          0     6    12    18    24    36    48    60    72    84    96   108   120
V (KT) NO LAND    25    26    28    30    33    41    52    62    67    71    75    78    81
V (KT) LAND       25    26    28    30    33    41    52    62    67    56    56    58    53
V (KT) LGE mod    25    24    24    25    26    29    33    39    46    43    45    51    50

SHEAR (KTS)        3     7    10     9     6     8     4     9     8    14     6    14     4
SHEAR DIR        120    50    35    49    74    31   209   268   251   351   336    14   128
SST (C)         29.0  28.7  28.6  28.6  28.6  28.5  28.7  28.8  28.8  28.9  29.2  29.3  29.2
POT. INT. (KT)   153   149   147   147   147   145   148   149   148   150   154   157   155
ADJ. POT. INT.   156   155   152   152   150   146   146   144   141   141   145   148   147
200 MB T (C)   -53.5 -53.6 -53.6 -53.3 -53.2 -53.7 -53.5 -54.0 -53.3 -53.5 -53.1 -53.4 -53.5
TH_E DEV (C)      10    10     9    10    11     9    11    10    12    11    12    11    12
700-500 MB RH     65    63    64    68    63    67    59    63    60    60    59    62    60
GFS VTEX (KT)      6     7  LOST  LOST  LOST  LOST  LOST  LOST  LOST  LOST  LOST  LOST  LOST
850 MB ENV VOR    52    40    37    45    42    42    30    19     9     0    -1     4    14
200 MB DIV        26    32    17    12    18    36    26     6    -8   -11     1     3     5
LAND (KM)        568   504   397   296   277   411   271   153    95   -23    26    80    -8
LAT (DEG N)     10.9  11.4  11.8  12.5  13.2  14.4  15.6  16.7  17.5  18.2  18.6  18.6  18.3
LONG(DEG W)     54.5  56.0  57.5  58.9  60.3  62.9  65.4  67.7  69.6  71.6  73.3  75.2  77.3
STM SPEED (KT)    12    15    15    15    15    14    13    11    10     9     9     9    10
HEAT CONTENT      66    62    74    81    73    63    78    82    85  9999     2    17    20

  FORECAST TRACK FROM BAMM      INITIAL HEADING/SPEED (DEG/KT):285/  9      CX,CY:  -8/  2
  T-12 MAX WIND:  30            PRESSURE OF STEERING LEVEL (MB):  637  (MEAN=625)
  GOES IR BRIGHTNESS TEMP. STD DEV. 100-300 KM RAD:  15.7 (MEAN=20.0)
  % GOES IR PIXELS WITH T < -20 C    50-200 KM RAD:  57.0 (MEAN=68.6)

                        INDIVIDUAL CONTRIBUTIONS TO INTENSITY CHANGE
                         6   12   18   24   36   48   60   72   84   96  108  120
                        ----------------------------------------------------------
  SAMPLE MEAN CHANGE     1.   2.   3.   4.   6.   8.   9.  10.  11.  12.  12.  13.
  SST POTENTIAL          0.   0.   0.   1.   6.  12.  19.  24.  29.  33.  36.  39.
  VERTICAL SHEAR         1.   2.   4.   5.   7.   9.  11.  12.  10.  11.   9.  10.
  PERSISTENCE           -2.  -3.  -4.  -5.  -6.  -6.  -6.  -5.  -4.  -3.  -1.   0.
  200/250 MB TEMP.       0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   1.
  THETA_E EXCESS         0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.
  700-500 MB RH          0.   0.   0.   0.   0.   0.   0.   0.   0.   0.  -1.  -2.
  GFS VORTEX TENDENCY    0.   0.   0.   0.   0.   0.   0.  -1.  -1.  -1.  -1.  -1.
  850 MB ENV VORTICITY   0.   0.   0.   1.   1.   1.   1.   1.   0.   0.   0.   0.
  200 MB DIVERGENCE      0.   0.   0.   0.   0.   1.   0.   0.  -1.  -1.  -1.  -1.
  ZONAL STORM MOTION     0.   0.   0.   1.   1.   1.   1.   1.   1.   2.   2.   2.
  STEERING LEVEL PRES    0.   0.   0.   0.   0.   0.   0.  -1.  -1.  -1.  -1.  -1.
  DAYS FROM CLIM. PEAK   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.
                        ----------------------------------------------------------
  SUB-TOTAL CHANGE       0.   1.   3.   6.  14.  25.  35.  42.  46.  51.  54.  59.

  SATELLITE ADJUSTMENTS ----------------------------------------------------------
  MEAN ADJUSTMENT        0.   0.   0.   0.  -1.  -1.  -1.  -1.  -1.  -1.  -1.  -2.
  GOES IR STD DEV        1.   2.   3.   3.   3.   2.   2.   0.  -1.  -1.  -1.  -1.
  GOES IR PIXEL COUNT    0.   0.   0.  -1.  -1.   0.   0.   0.   1.   1.   1.   0.
  OCEAN HEAT CONTENT     0.   0.   0.   0.   0.   0.   0.   1.   1.   0.  -1.  -1.
                        ----------------------------------------------------------
  TOTAL ADJUSTMENT       1.   1.   2.   2.   2.   1.   1.   1.   0.  -1.  -2.  -3.
                        ----------------------------------------------------------
  TOTAL CHANGE (KT)      1.   3.   5.   8.  16.  27.  37.  42.  46.  50.  53.  56.

   ** 2008 ATLANTIC RI INDEX AL942008     INVEST 08/23/08  00 UTC **
           ( 25 KT OR MORE MAX WIND INCREASE IN NEXT 24 HR)
 
 12 HR PERSISTENCE (KT):  -5.0 Range:-45.0 to  30.0 Scaled/Wgted Val:  0.5/  1.0
 850-200 MB SHEAR (KT) :   7.1 Range: 35.1 to   3.2 Scaled/Wgted Val:  0.9/  1.4
 D200 (10**7s-1)       :  21.0 Range:-20.0 to 149.0 Scaled/Wgted Val:  0.2/  0.4
 POT = MPI-VMAX (KT)   : 128.1 Range: 25.1 to 130.7 Scaled/Wgted Val:  1.0/  1.1
 850-700 MB REL HUM (%):  74.6 Range: 56.0 to  88.0 Scaled/Wgted Val:  0.6/  0.2
 % area w/pixels <-30 C:  43.0 Range: 17.0 to 100.0 Scaled/Wgted Val:  0.3/  0.1
 STD DEV OF IR BR TEMP :  12.1 Range: 35.1 to   3.2 Scaled/Wgted Val:  0.7/  0.9
 Heat content (KJ/cm2) :  71.2 Range:  0.0 to 132.0 Scaled/Wgted Val:  0.5/  0.0
 
 Prob of RI for 25 kt RI threshold=    36% is   2.9 times the sample mean(12.3%)
 Prob of RI for 30 kt RI threshold=    18% is   2.3 times the sample mean( 7.8%)
 Prob of RI for 35 kt RI threshold=     9% is   2.1 times the sample mean( 4.5%)

   ##         ANNULAR HURRICANE INDEX (AHI) AL942008     INVEST 08/23/08  00 UTC         ##
   ## STORM NOT ANNULAR, SCREENING STEP FAILED, NPASS=4 NFAIL=3                          ##
   ## AHI=  0   (AHI OF 100 IS BEST FIT TO ANN. STRUC., 1 IS MARGINAL, 0 IS NOT ANNULAR) ##
   ##     ANNULAR INDEX RAN NORMALLY

[ROCK]

0z GFS should give us some clues tonight......


on a side note: Ed nice to see you posting about this system. I am sure this will never make it into the GOM nor will Texas be effected whatsoever.....

[RL3AO]

Impressive RI probs.

[Blown Away]

http://www.ecmwf.int/products/forecasts/d/charts/medium/deterministic/msl_uv850_z500!Wind%20850%20and%20mslp!240!North%20America!pop!od!oper!public_plots!2008082212!!/

The Euro looks like a Hurricane David track, but much weaker.

[Wthrman13]

looks like nothing was really inserted into the model as it starts as dissipated

Yeah, I noticed that, the initial vortex is way too weak. I never really liked the way that the GFDL is initialized anyway. It's essentially a bogus vortex inserted to match the NHC's thinking of its current intensity. I know they have to do it that way due to lack of data on that scale, and in my own research I often have to start my thunderstorm simulations with fake thermal bubbles, but it just goes to show how sensitive the subsequent forecast of the storm in the GFDL (and HWRF) are to this initial vortex.

[Ed Mahmoud]

0z GFS should give us some clues tonight......


on a side note: Ed nice to see you posting about this system. I am sure this will never make it into the GOM nor will Texas be effected whatsoever.....

The GOM includes Mexico, and Louisiana, Mississippi, Alabama and Florida. An Autumn like weather pattern does not spare the Central and Eastern Gulf from tropical threats. Lili, Isidore, Juan, Wilma, Opal, all seem to come to mind as Autumn GOMEX storms.

I make the simple observation we have had over a week of Westerlies, and multiple cold front passages, and that one hurricane (barely a hurricane) in sixty years has hit Texas in October, and some people get all upset like I'm trying to cancel Christmas, Chanukkah, Kwanzaa and New Years. And Chinese New Years. And the Super Bowl.


Anyhoo, too early to even say if this develops, and, if per chance, evidence suggests to me this could threaten someplace not usually affected by storms in an Autumnal pattern, or the pattern flips back (and I'll admit about half the 12Z GFS ensemble members would not absolutely, positively, guarantee protection for Texas at hour 180) I'll be the first to admit it.


But absolutely gut, totally unofficial speculation, this early out, either is a low runner menacing Central America/Western Caribbean, or if it feels the trough at all, it really feels it, and menaces Lousiana to Florida, probably Florida.

That is speculation, way too early to predict, it may never develop, or it may commit seppeku on the 3 km peaks of Hispaniola. Just a SWAG, not worth the electrons it glows on the monitor with.

[Ed Mahmoud]

BTW, if this doesn't gain latitude soon, it could start suffering land interaction with South America.

[LaBreeze]

Don't forget Rita was in the latter part of September also. We will never forget her.

[Ed Mahmoud]

May not mean much, but new 0Z GFS doesn't even seem to carry much if any of an 850 vorticity maximum with 94L through 3 days...


Edit to add- the NAM, not exactly known as a tropical model, does see a tropical depression moving Northwest to the South of Hispaniola...

[Sanibel]

GFDL doesn't grab it either but CMC does and sends it up above the islands and what looks like the beginning of recurve. Funny because IR close-up is showing what looks to be the beginning of a new center burst.

[ROCK]

0z GFS should give us some clues tonight......


on a side note: Ed nice to see you posting about this system. I am sure this will never make it into the GOM nor will Texas be effected whatsoever.....

The GOM includes Mexico, and Louisiana, Mississippi, Alabama and Florida. An Autumn like weather pattern does not spare the Central and Eastern Gulf from tropical threats. Lili, Isidore, Juan, Wilma, Opal, all seem to come to mind as Autumn GOMEX storms.

I make the simple observation we have had over a week of Westerlies, and multiple cold front passages, and that one hurricane (barely a hurricane) in sixty years has hit Texas in October, and some people get all upset like I'm trying to cancel Christmas, Chanukkah, Kwanzaa and New Years. And Chinese New Years. And the Super Bowl.


Anyhoo, too early to even say if this develops, and, if per chance, evidence suggests to me this could threaten someplace not usually affected by storms in an Autumnal pattern, or the pattern flips back (and I'll admit about half the 12Z GFS ensemble members would not absolutely, positively, guarantee protection for Texas at hour 180) I'll be the first to admit it.


But absolutely gut, totally unofficial speculation, this early out, either is a low runner menacing Central America/Western Caribbean, or if it feels the trough at all, it really feels it, and menaces Lousiana to Florida, probably Florida.

That is speculation, way too early to predict, it may never develop, or it may commit seppeku on the 3 km peaks of Hispaniola. Just a SWAG, not worth the electrons it glows on the monitor with.

Thanks Ed.....

[zaqxsw75050]

May not mean much, but new 0Z GFS doesn't even seem to carry much if any of an 850 vorticity maximum with 94L through 3 days...

GFS has 94L in inland South America in 18 hours...

[ROCK]

not the greatest of runs tonight as the GFS never developes 94L...I did notice at 138H there is a big fat high sitting over the GOM.....just like an Autumn pattern...

http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_138l.gif

[srainhoutx]

not the greatest of runs tonight as the GFS never developes 94L...I did notice at 138H there is a big fat high sitting over the GOM.....just like an Autumn pattern...

http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_138l.gif

Ahhh those 50 degree dew points. One can only dream.