Tropical Storm Bertha Model Runs

[Frank2]

And I've asked enough of 'em...

LOL

P.S. Anyway, I still think Bertha is now on a new heading - we'll see at 5...

[Ivanhater]

Updated model map...still a split

[vacanechaser]

Apparently Bertha is back to a WNW heading:

http://www.ssd.noaa.gov/goes/flt/t1/loop-vis.html

it seems to be crossing 18N at this time, so, perhaps the turn shown by most models might come sooner than later...

after looking at the satellite image-loop, for some time now, i think what you may be seeing there frank is the upper level, or mid level center... the main low level circulation is still south of that area and moving due west... it may pass just south of the next forecast point if you overlay that on the sat images..


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

[Aric Dunn]

Updated model map...still a split

think the gfs is doing well .. the gfdl ,hwrf are having some problems.. with the strength of the ridge from that 12z run bertha should have a heading almost NW and that is far from it..

although even the gfs has 290 heading right now.. but it turns it back west..
this is a big problem .. if that cant even get the short term correct how can we have any faith in them..

[Ivanhater]

12 z CMC... lol..shift south



P.S.if anybody is watching the mens final live at Wimbledon..very exciting!..Venus and Serena played yesterday and Venus won...

[MiamiensisWx]

Those who were adamantly sticking to an early recurvature are being forced to strongly reconsider their original views at this critical juncture. We are rapidly approaching the stage where it's becoming very tempting to discard the model guidance's solutions shown in the chart (above). Bertha continues to move west; in fact, it is even potentially passing just south of the next TPC forecast position (again). The model "cluster" indicates a current WNW movement and a slightly slower forward speed, when that is clearly not the case.

[Aric Dunn]

The models are going to have to react to the lack of nw motion they are calling for.. maybe by the 00z they will shift west in accordance with the continued westward motion.

[Aric Dunn]

12 z CMC... lol..shift south



P.S.if anybody is watching the mens final live at Wimbledon..very exciting!..Venus and Serena played yesterday and Venus won...

yes that is a quite a shift south and west for the cmc.. interesting..

[KWT]

The high resolution models are probably suffering from the same issues that they suffered with Dean where it constantly tried to take the system northwards but it just wouldn't budge.
GFS and the UKMO in good agreement as for as long as the UKMO has it anyway.

CMC is just downright scary and not too far away from the 12z GFS.

[RL3AO]

UKMET is a little further north and closer to consensus.

[Aric Dunn]

The high resolution models are probably suffering from the same issues that they suffered with Dean where it constantly tried to take the system northwards but it just wouldn't budge.
GFS and the UKMO in good agreement as for as long as the UKMO has it anyway.

CMC is just downright scary and not too far away from the 12z GFS.

agreed this is very similar to last years problem.. the ridge is quite strong at this point and NW turn today is highly unlikely so the gfdl , hwrf and a few others are being disregarded by me at this point till the next run to see if they account for the west motion

[Scorpion]

I think it would help greatly if they sent a NOAA plane into the vicinity and really sample the environment.

[cycloneye]

WHXX01 KWBC 061841
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1841 UTC SUN JUL 6 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

TROPICAL CYCLONE BERTHA (AL022008) 20080706 1800 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
080706 1800 080707 0600 080707 1800 080708 0600

LAT LON LAT LON LAT LON LAT LON
BAMS 17.8N 46.2W 18.7N 50.0W 19.6N 53.3W 19.9N 56.1W
BAMD 17.8N 46.2W 18.9N 49.1W 19.9N 51.2W 20.6N 52.7W
BAMM 17.8N 46.2W 18.8N 49.4W 19.7N 51.9W 20.3N 53.7W
LBAR 17.8N 46.2W 18.6N 49.3W 19.5N 52.4W 20.1N 54.9W
SHIP 45KTS 50KTS 57KTS 61KTS
DSHP 45KTS 50KTS 57KTS 61KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
080708 1800 080709 1800 080710 1800 080711 1800

LAT LON LAT LON LAT LON LAT LON
BAMS 20.7N 58.7W 22.8N 63.2W 25.4N 66.6W 26.7N 67.8W
BAMD 21.4N 54.0W 23.2N 56.3W 25.0N 57.7W 24.6N 58.8W
BAMM 21.1N 55.5W 23.1N 58.6W 25.2N 60.8W 25.7N 62.3W
LBAR 21.2N 57.0W 23.6N 60.9W 26.5N 62.9W 27.0N 63.4W
SHIP 64KTS 63KTS 61KTS 65KTS
DSHP 64KTS 63KTS 61KTS 65KTS

...INITIAL CONDITIONS...
LATCUR = 17.8N LONCUR = 46.2W DIRCUR = 280DEG SPDCUR = 18KT
LATM12 = 17.0N LONM12 = 42.3W DIRM12 = 277DEG SPDM12 = 19KT
LATM24 = 16.6N LONM24 = 38.4W
WNDCUR = 45KT RMAXWD = 30NM WNDM12 = 45KT
CENPRS = 1000MB OUTPRS = 1012MB OUTRAD = 180NM SDEPTH = D
RD34NE = 75NM RD34SE = 30NM RD34SW = 0NM RD34NW = 75NM

[KWT]

Hmmm they start it at 17.8 yet the Dvarok suggests 17.4, thats quite a large difference in terms of intial starting points!

[cycloneye]

The 18:00 UTC SHIP forecast: Shear is not an issue as you can see.

Code: Select all

                 *   ATLANTIC SHIPS INTENSITY FORECAST       *
                    *        GOES/OHC INPUT INCLUDED            *
                    *      BERTHA  AL022008  07/06/08  18 UTC   *

TIME (HR)          0     6    12    18    24    36    48    60    72    84    96   108   120
V (KT) NO LAND    45    47    50    54    57    61    64    63    63    61    61    63    65
V (KT) LAND       45    47    50    54    57    61    64    63    63    61    61    63    65
V (KT) LGE mod    45    46    47    49    51    57    61    64    64    63    63    65    67

SHEAR (KTS)        8    10     9     7     8    14    14    23    15    20    12     4     8
SHEAR DIR        203   204   238   263   261   259   268   264   257   254   309     6    95
SST (C)         26.1  26.4  26.7  27.0  27.3  27.7  27.9  27.9  27.9  28.0  27.9  27.8  27.8
POT. INT. (KT)   117   120   123   126   129   133   136   136   136   137   135   133   132
ADJ. POT. INT.   115   117   118   120   122   125   127   125   123   123   119   115   113
200 MB T (C)   -54.5 -54.3 -54.4 -54.5 -54.1 -54.2 -54.7 -54.9 -55.3 -55.0 -55.2 -55.2 -55.0
TH_E DEV (C)       9     9     9     9    10    10    10    10    10    10    10    11    10
700-500 MB RH     46    48    45    43    45    42    44    45    45    46    45    42    49
GFS VTEX (KT)     11    11    11    11    12    11    12     9     8     7     6     5     6
850 MB ENV VOR    56    56    54    54    48    27    20   -13   -36   -63   -74   -96   -55
200 MB DIV        50    59    52    46    22    13    -6    -4    -5    -2     0   -11   -25
LAND (KM)       1578  1539  1500  1411  1336  1154   932   763   700   722   820   879   922
LAT (DEG N)     17.8  18.2  18.6  19.1  19.5  20.3  21.1  22.1  23.3  24.5  25.8  26.8  27.6
LONG(DEG W)     46.2  47.9  49.6  51.0  52.4  54.9  57.3  59.6  61.6  63.3  64.8  66.1  67.1
STM SPEED (KT)    18    17    15    14    13    12    12    11    11    10     8     7     6
HEAT CONTENT       3     7    16    21    24    35    40    34    28    28    28    20    14

  FORECAST TRACK FROM OFCI      INITIAL HEADING/SPEED (DEG/KT):280/ 18      CX,CY: -17/  3
  T-12 MAX WIND:  45            PRESSURE OF STEERING LEVEL (MB):  683  (MEAN=625)
  GOES IR BRIGHTNESS TEMP. STD DEV. 100-300 KM RAD:  20.5 (MEAN=20.0)
  % GOES IR PIXELS WITH T < -20 C    50-200 KM RAD:  88.0 (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.   1.   1.   2.   3.   5.   8.  10.  11.  11.  11.  11.
  VERTICAL SHEAR         1.   1.   3.   4.   5.   4.   3.   3.   2.   2.   3.   5.
  PERSISTENCE            0.  -1.  -1.  -1.  -1.  -1.  -1.  -1.  -1.  -1.   0.   0.
  200/250 MB TEMP.       0.   0.   0.   1.   1.   2.   2.   3.   3.   4.   5.   6.
  THETA_E EXCESS         0.   0.   0.  -1.  -1.  -1.  -1.  -1.  -2.  -2.  -2.  -2.
  700-500 MB RH          0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.
  GFS VORTEX TENDENCY    0.   0.   0.   0.   0.   0.  -2.  -3.  -5.  -6.  -7.  -6.
  850 MB ENV VORTICITY   0.   0.   1.   1.   1.   1.   1.   0.  -1.  -2.  -3.  -4.
  200 MB DIVERGENCE      0.   1.   1.   1.   1.   1.   0.   0.  -1.  -1.  -2.  -2.
  ZONAL STORM MOTION     0.   0.   1.   1.   3.   3.   4.   5.   5.   6.   7.   8.
  STEERING LEVEL PRES    0.   0.   0.   0.  -1.  -1.  -1.  -2.  -2.  -2.  -2.  -1.
  DAYS FROM CLIM. PEAK   0.   0.   0.  -1.  -1.  -2.  -2.  -2.  -2.  -3.  -3.  -4.
                        ----------------------------------------------------------
  SUB-TOTAL CHANGE       2.   4.   7.  11.  15.  19.  19.  19.  19.  19.  21.  23.

  SATELLITE ADJUSTMENTS ----------------------------------------------------------
  MEAN ADJUSTMENT        0.   0.   0.   0.  -1.  -1.  -1.  -1.  -1.  -1.  -1.  -2.
  GOES IR STD DEV        0.   1.   1.   1.   1.   1.   1.   0.   0.   0.   0.   0.
  GOES IR PIXEL COUNT    0.   0.   1.   1.   1.   0.   0.   0.   0.   0.  -1.   0.
  OCEAN HEAT CONTENT     0.   0.   0.   0.   0.   0.  -1.  -1.  -1.  -1.  -1.  -1.
                        ----------------------------------------------------------
  TOTAL ADJUSTMENT       1.   1.   1.   1.   1.   0.  -1.  -2.  -3.  -3.  -3.  -2.
                        ----------------------------------------------------------
  TOTAL CHANGE (KT)      2.   5.   9.  12.  16.  19.  18.  18.  16.  16.  18.  20.

   ** 2008 ATLANTIC RI INDEX AL022008     BERTHA 07/06/08  18 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) :   8.4 Range: 35.1 to   3.2 Scaled/Wgted Val:  0.8/  1.3
 D200 (10**7s-1)       :  45.8 Range:-20.0 to 149.0 Scaled/Wgted Val:  0.4/  0.6
 POT = MPI-VMAX (KT)   :  73.5 Range: 25.1 to 130.7 Scaled/Wgted Val:  0.5/  0.5
 850-700 MB REL HUM (%):  62.4 Range: 56.0 to  88.0 Scaled/Wgted Val:  0.2/  0.1
 % area w/pixels <-30 C:  81.0 Range: 17.0 to 100.0 Scaled/Wgted Val:  0.8/  0.2
 STD DEV OF IR BR TEMP :  10.1 Range: 35.1 to   3.2 Scaled/Wgted Val:  0.8/  1.0
 Heat content (KJ/cm2) :  14.2 Range:  0.0 to 132.0 Scaled/Wgted Val:  0.1/  0.0
 
 Prob of RI for 25 kt RI threshold=    24% is   2.0 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   2.0 times the sample mean( 4.5%)

   ##         ANNULAR HURRICANE INDEX (AHI) AL022008     BERTHA 07/06/08  18 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

[RL3AO]

Side note: The RI index is slowly rising.

[Duddy]

The models are not doing well. In fact, they are doing horribly. I don't see Bertha curving North anytime before landfall.


I personally expect to see Hurricane Bertha just North of the Bahamas in a couple days.

[Duddy]

Side note: The RI index is slowly rising.

I saw that, looks like another active season soo far.

[Derek Ortt]

most models, except for HWRF have been OUTSTANDING on Bertha

There is no reaosn to totally discount them... unless one does not like what they say

[KWT]

SST's are only going to increase from now on and so as long as the shear doesn't get too high (it does go upto 20kts which would halt development) then we should see steady development of this system, still progging a marginal hurricane.

Derek, they have been ok but they did recurve WAY too soon, the GFDL for example was at 22-23N at 45W at one point.