ATL Tropical Depression GUSTAV - Model Runs

[cycloneye]

06z GFDL does not make it a hurricane in this run.

http://moe.met.fsu.edu/cgi-bin/gfdltc2. ... =Animation

06z HWRF crashes into Hispanola.

http://moe.met.fsu.edu/cgi-bin/hwrftc2. ... =Animation

[USTropics]

Near the end of the HWRF run you can see a decent tropical system to the north. Looks to be the same tropical wave about to emerge off of Africa that the GFS has forming. Alas, that's for another thread but thought it should be noted.

[Normandy]

http://cimss.ssec.wisc.edu/tropic/real- ... 8dlm1.html

The globals are completely crazy to even think about having this system threaten PR or the DR at this point, especially given its lattitude. I would say this is more of a threat to Jamaica then either of those two. Its already almost due south of PR and its screaming WNW.

[Portastorm]

I'm with you Normandy. It's very hard to believe the system would gain that much latitude that quickly. However, that being said, I did read a post from a pro met on another board who said that a piece of the trough off the East Coast may "pinch off" and move south, thus eliciting a greater poleward movement of 94L.

Given that 94L is still disorganized, safest to go with the lower level flow (i.e. easterlies). Can't see this system doing anything but moving west or west-northwest for a few more days.

[cycloneye]

WHXX01 KWBC 241250
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1250 UTC SUN AUG 24 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) 20080824 1200 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
080824 1200 080825 0000 080825 1200 080826 0000

LAT LON LAT LON LAT LON LAT LON
BAMS 12.1N 64.6W 12.8N 67.0W 13.9N 69.5W 15.0N 71.3W
BAMD 12.1N 64.6W 13.1N 67.3W 14.2N 69.8W 15.0N 72.0W
BAMM 12.1N 64.6W 13.1N 67.2W 14.2N 69.7W 15.1N 71.9W
LBAR 12.1N 64.6W 13.2N 67.2W 14.4N 70.0W 15.8N 72.4W
SHIP 25KTS 30KTS 38KTS 45KTS
DSHP 25KTS 30KTS 38KTS 45KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
080826 1200 080827 1200 080828 1200 080829 1200

LAT LON LAT LON LAT LON LAT LON
BAMS 15.7N 72.8W 17.0N 75.6W 17.1N 78.1W 16.9N 81.3W
BAMD 15.4N 74.3W 15.8N 78.9W 15.6N 83.3W 15.2N 87.6W
BAMM 15.8N 73.9W 16.2N 77.5W 16.0N 81.4W 15.5N 85.6W
LBAR 17.0N 74.5W 18.4N 77.7W 18.4N 80.9W 17.6N 83.9W
SHIP 53KTS 66KTS 77KTS 86KTS
DSHP 53KTS 66KTS 77KTS 55KTS

...INITIAL CONDITIONS...
LATCUR = 12.1N LONCUR = 64.6W DIRCUR = 285DEG SPDCUR = 12KT
LATM12 = 11.1N LONM12 = 62.4W DIRM12 = 285DEG SPDM12 = 12KT
LATM24 = 10.9N LONM24 = 59.6W
WNDCUR = 25KT RMAXWD = 90NM WNDM12 = 25KT
CENPRS = 1008MB OUTPRS = 1010MB OUTRAD = 150NM SDEPTH = M
RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM

$$

[Derek Ortt]

the globals make perfect sense going with the turn to the NW

There is a MASSIVE weakness in the subtropical high. Don't use the shallow steering. There is deep convection associated with the broad low. This is likely to follow a deeper layer steering flow

[gatorcane]

Derek I agree with the NW turn that should happen soon ---

but looks like if this thing makes it past the big islands it could bend back west or west northwest. Does ridging build back in in the long-run? For example NOGAPS bends it back into the SE Bahamas heading W or WNW.

[cycloneye]

According to the latest 12:00 UTC SHIP forecast,shear will be mainly light.

Code: Select all

             *   ATLANTIC SHIPS INTENSITY FORECAST       *
                    *        GOES/OHC INPUT INCLUDED            *
                    *      INVEST  AL942008  08/24/08  12 UTC   *

TIME (HR)          0     6    12    18    24    36    48    60    72    84    96   108   120
V (KT) NO LAND    25    28    30    34    38    45    53    60    66    71    77    83    86
V (KT) LAND       25    28    30    34    38    45    53    60    66    71    77    83    55
V (KT) LGE mod    25    26    27    28    30    35    42    50    57    66    76    85    59

SHEAR (KTS)       13     7     5     2     6     6     9     7     7     3     7     3     4
SHEAR DIR         73    85   120    46   358    98    31    94    30   123     2   265   349
SST (C)         28.1  28.2  28.5  28.6  28.5  28.3  28.3  28.4  28.5  28.6  28.7  28.7  29.0
POT. INT. (KT)   139   141   145   147   145   141   141   142   143   145   147   147   152
ADJ. POT. INT.   140   142   147   147   143   137   135   135   137   138   141   142   148
200 MB T (C)   -53.7 -52.7 -53.2 -53.6 -53.9 -53.2 -53.7 -53.3 -53.7 -53.7 -53.9 -53.6 -53.8
TH_E DEV (C)       9    10    10     9     9    11    10    11    11    12    10    12    10
700-500 MB RH     72    72    69    66    69    67    65    61    62    63    62    61    63
GFS VTEX (KT)     10    11     8     8     7     6     4     4     5     6     7     9     9
850 MB ENV VOR    55    52    56    54    51    43    29    23    23    19    16    24    52
200 MB DIV        26    63    61    51    50    34    22     4    -6     8    10   -15    14
LAND (KM)        168   223   246   240   235   282   244   188   169   251   222    56   -37
LAT (DEG N)     12.1  12.6  13.1  13.7  14.2  15.1  15.8  16.2  16.2  16.2  16.0  15.7  15.5
LONG(DEG W)     64.6  65.9  67.2  68.5  69.7  71.9  73.9  75.6  77.5  79.4  81.4  83.4  85.6
STM SPEED (KT)    13    14    14    13    12    11     9     9     9     9    10    10    11
HEAT CONTENT      33    44    41    35    52    72    77    65    71     4     7     4  9999

  FORECAST TRACK FROM BAMM      INITIAL HEADING/SPEED (DEG/KT):285/ 12      CX,CY: -11/  3
  T-12 MAX WIND:  25            PRESSURE OF STEERING LEVEL (MB):  567  (MEAN=625)
  GOES IR BRIGHTNESS TEMP. STD DEV. 100-300 KM RAD:  25.3 (MEAN=20.0)
  % GOES IR PIXELS WITH T < -20 C    50-200 KM RAD:  86.0 (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.   2.   5.  11.  17.  22.  27.  31.  34.  36.
  VERTICAL SHEAR         1.   2.   4.   5.   8.   9.  10.  11.  12.  12.  13.  14.
  PERSISTENCE            0.  -1.  -1.  -1.  -1.  -1.  -1.  -1.  -1.  -1.   0.   0.
  200/250 MB TEMP.       0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   1.   1.
  THETA_E EXCESS         0.   0.   0.   0.   0.  -1.  -1.  -1.  -1.  -1.  -1.  -1.
  700-500 MB RH          0.   0.   0.   0.   0.   0.   0.   0.   0.   0.  -2.  -2.
  GFS VORTEX TENDENCY    0.  -1.  -1.  -2.  -4.  -5.  -6.  -5.  -5.  -4.  -3.  -3.
  850 MB ENV VORTICITY   0.   0.   1.   1.   1.   1.   1.   1.   1.   1.   1.   1.
  200 MB DIVERGENCE      0.   0.   1.   1.   2.   2.   2.   1.   1.   1.   0.   0.
  ZONAL STORM MOTION     0.   0.   1.   1.   1.   2.   2.   2.   3.   3.   4.   4.
  STEERING LEVEL PRES    0.   0.   0.   0.   1.   1.   1.   1.   1.   1.   1.   1.
  DAYS FROM CLIM. PEAK   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   1.
                        ----------------------------------------------------------
  SUB-TOTAL CHANGE       2.   4.   7.  11.  19.  27.  35.  43.  49.  55.  61.  64.

  SATELLITE ADJUSTMENTS ----------------------------------------------------------
  MEAN ADJUSTMENT        0.   0.   0.   0.  -1.  -1.  -1.  -1.  -1.  -1.  -1.  -2.
  GOES IR STD DEV        1.   1.   2.   2.   2.   2.   1.   0.   0.   0.   0.   0.
  GOES IR PIXEL COUNT    0.   0.   1.   1.   1.   0.   0.   0.   0.   0.   0.   0.
  OCEAN HEAT CONTENT     0.   0.   0.   0.   0.   0.  -1.  -1.  -1.  -1.  -1.  -1.
                        ----------------------------------------------------------
  TOTAL ADJUSTMENT       1.   1.   2.   2.   2.   1.   0.  -2.  -3.  -3.  -3.  -3.
                        ----------------------------------------------------------
  TOTAL CHANGE (KT)      3.   5.   9.  13.  20.  28.  35.  41.  46.  52.  58.  61.

   ** 2008 ATLANTIC RI INDEX AL942008     INVEST 08/24/08  12 UTC **
           ( 25 KT OR MORE MAX WIND INCREASE IN NEXT 24 HR)
 
 12 HR PERSISTENCE (KT):   0.0 Range:-45.0 to  30.0 Scaled/Wgted Val:  0.6/  1.1
 850-200 MB SHEAR (KT) :   6.6 Range: 35.1 to   3.2 Scaled/Wgted Val:  0.9/  1.4
 D200 (10**7s-1)       :  50.2 Range:-20.0 to 149.0 Scaled/Wgted Val:  0.4/  0.6
 POT = MPI-VMAX (KT)   : 118.9 Range: 25.1 to 130.7 Scaled/Wgted Val:  0.9/  1.0
 850-700 MB REL HUM (%):  74.0 Range: 56.0 to  88.0 Scaled/Wgted Val:  0.6/  0.2
 % area w/pixels <-30 C:  80.0 Range: 17.0 to 100.0 Scaled/Wgted Val:  0.8/  0.2
 STD DEV OF IR BR TEMP :  11.5 Range: 35.1 to   3.2 Scaled/Wgted Val:  0.7/  1.0
 Heat content (KJ/cm2) :  41.0 Range:  0.0 to 132.0 Scaled/Wgted Val:  0.3/  0.0
 
 Prob of RI for 25 kt RI threshold=    46% is   3.7 times the sample mean(12.3%)
 Prob of RI for 30 kt RI threshold=    29% is   3.8 times the sample mean( 7.8%)
 Prob of RI for 35 kt RI threshold=    22% is   4.9 times the sample mean( 4.5%)

   ##         ANNULAR HURRICANE INDEX (AHI) AL942008     INVEST 08/24/08  12 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 

[Portastorm]

the globals make perfect sense going with the turn to the NW

There is a MASSIVE weakness in the subtropical high. Don't use the shallow steering. There is deep convection associated with the broad low. This is likely to follow a deeper layer steering flow

Thanks for clarifying, Derek. After looking at the steering flow maps more closely (and at different levels), you are absolutely right. I will defer to your judgment any day on these things!

[deltadog03]

Look at the %prob. for RI...Pretty high for all 3 of them!!

[Ed Mahmoud]

Looks a lot better now than 12 hours ago. Interesting that Euro matches Bastardi's idea of a SE US coast threat.


I'm hoping JB will have posted by the time I get back from church.

[Emmett_Brown]

Here is the 48 hr GFS 500 mb (Derek, I am assuming that this is the steering level we should use). Shows weak high surpressed south, but still seems to have enough strength to steer a system between WNW and NW imo. Perhaps a track toward E Cuba?

[USTropics]

Jeff Masters was on WWL this morning and said he is concerned about 94L. He's thinking western Bahamas right now, but is not confident on that prediction. He also said he expects at least 2 tropical storms to be named in the next 2 weeks.

http://www.mediafire.com/?sharekey=620e8ecf54b757d0d2db6fb9a8902bda

[Emmett_Brown]

Looks a lot better now than 12 hours ago. Interesting that Euro matches Bastardi's idea of a SE US coast threat.


I'm hoping JB will have posted by the time I get back from church.

Anybody have a good link for the Euro? Cant find it in my bookmarks for some reason...

[USTropics]

Looks a lot better now than 12 hours ago. Interesting that Euro matches Bastardi's idea of a SE US coast threat.


I'm hoping JB will have posted by the time I get back from church.

Anybody have a good link for the Euro? Cant find it in my bookmarks for some reason...

http://www.ecmwf.int/products/forecasts ... 8082400!!/

[cheezyWXguy]

the globals make perfect sense going with the turn to the NW

There is a MASSIVE weakness in the subtropical high. Don't use the shallow steering. There is deep convection associated with the broad low. This is likely to follow a deeper layer steering flow

Yeah I agree with the NW turn...but not yet. All models headed for Hispaniola initialized with a motion too far north. This thing is probably headed 280 or 285 right now, not 295 or 300. Therefore, I think the target shifts from DR/Haiti, to Jamaica and western Cuba.

[jlauderdal]

Jeff Masters was on WWL this morning and said he is concerned about 94L. He's thinking western Bahamas right now, but is not confident on that prediction. He also said he expects at least 2 tropical storms to be named in the next 2 weeks.

http://www.mediafire.com/?sharekey=620e8ecf54b757d0d2db6fb9a8902bda

thats just great, fortunately this far out most tracks arent nailed, good luck texas or NC

[deltadog03]

the globals make perfect sense going with the turn to the NW

There is a MASSIVE weakness in the subtropical high. Don't use the shallow steering. There is deep convection associated with the broad low. This is likely to follow a deeper layer steering flow

Yeah I agree with the NW turn...but not yet. All models headed for Hispaniola initialized with a motion too far north. This thing is probably headed 280 or 285 right now, not 295 or 300. Therefore, I think the target shifts from DR/Haiti, to Jamaica and western Cuba.

Agreed!

[cpdaman]

derek do you actually think conditions will be favorable in the central northern caribean

i mean there is some heavy shear from the north around that ULL that doesn't appear to be in a hurry to move, isn't this shear a bit of a wild card, or am i wrong.

[Derek Ortt]

derek do you actually think conditions will be favorable in the central northern caribean

i mean there is some heavy shear from the north around that ULL that doesn't appear to be in a hurry to move, isn't this shear a bit of a wild card, or am i wrong.

I dont see favorable conditions

if this develops, it could easily go the way of HWRF... a short lived sheared TS