Tropical Storm Bertha Model Runs

[Meso]

Here is the 00z EURO

72 Hours
Already fairly strong

240 Hours
Has a strong storm heading out to sea...Same hour there is another small low just off Africa (remember old GFS runs showed another storm after 92l).But probably nothing

[Extremeweatherguy]

[Extremeweatherguy]

It still looks like this supposed NW turn will have a lot to do with strength of the system. The models that want to develop this system quickly (GFS, EURO...), all want to try and take the storm out to sea, while the models that want to develop this system slowly (UKMET, CMC, NOGAPS...), al tend to take the storm further west. It still looks like it will be a few more days before we really know what will happen.

[KWT]

Yep alot of models are developing this system quickly and then take the system off to the NW fairly quickly as well. We shall see what happens. ECM strengthens the system then starts to weaken again by 144hrs, only to restrengthen again by 240hrs.

GFS looks to be on the northern side of the guidence with UKMO seeming to be on the left hand side.

GFS also makes this into a powerful system, indeed I'd guess that would quite possibily be a hurricane...we shall have to see what happens won't we!

[KWT]

06z now coming out, at 66hrs once again we've got a pretty well develop low pressure:

http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_066l.gif

[cycloneye]

Look where is 92L and turn your attention to the lower right part,all this in 240 hours on the 06z GFS run.

[ronjon]

Where are the GFDL runs for 92L? I haven't seen one posted yet on any of the model sites.

[KWT]

Very interesting run cycloneye, it heads NW then the weakness closes up and allows 92L to head westwards for about 48hrs before the ridge starts to break down totally and the system gets lifted up into the subtropics and towards the northern latitudes.

also yep I'm wondering about the GFDL as well, I can only see Boris and TD4-E being ran at the moment.

does anyone have a link to the SHIPS output by the way?

[cycloneye]

Very interesting run cycloneye, it heads NW then the weakness closes up and allows 92L to head westwards for about 48hrs before the ridge starts to break down totally and the system gets lifted up into the subtropics and towards the northern latitudes.

also yep I'm wondering about the GFDL as well, I can only see Boris and TD4-E being ran at the moment.

does anyone have a link to the SHIPS output by the way?

Here is the 06z SHIP forecast.

Code: Select all

            *   ATLANTIC SHIPS INTENSITY FORECAST       *
                    *     GOES AND/OR OHC INPUT MISSING         *
                    *      INVEST  AL922008  07/02/08  06 UTC   *

TIME (HR)          0     6    12    18    24    36    48    60    72    84    96   108   120
V (KT) NO LAND    25    27    30    35    39    48    59    71    81    85    86    85    83
V (KT) LAND       25    27    30    35    39    48    59    71    81    85    86    85    83
V (KT) LGE mod    25    25    26    28    29    33    38    45    53    60    65    69    69

SHEAR (KTS)       11     6     8     8    10    10     7     9     4     6     7    12    18
SHEAR DIR         95   128   107   120   134   136    98    57   111    45   255   274   248
SST (C)         27.6  27.1  26.7  26.3  26.1  26.3  26.5  26.2  25.4  24.9  25.1  25.5  26.1
POT. INT. (KT)   132   126   122   118   116   117   118   115   110   107   109   111   116
ADJ. POT. INT.   132   124   120   116   114   115   115   111   107   104   105   105   108
200 MB T (C)   -53.9 -53.5 -52.9 -53.5 -53.8 -52.9 -53.5 -52.4 -53.7 -52.5 -53.6 -53.0 -53.0
TH_E DEV (C)       3     3     4     4     4     4     5     5     5     5     5     5     6
700-500 MB RH     85    79    78    76    76    73    71    67    69    66    68    59    54
GFS VTEX (KT)     15    16    16    18    19    19    21    24    25    24    23    24    24
850 MB ENV VOR    79    84    95    97   103   130   158   165   151   129    98    56    27
200 MB DIV        82    94   130    97   112   107   107    95    94    91    48    30    44
LAND (KM)        384   507   631   760   888  1159  1395  1550  1694  1924  2183  2256  2355
LAT (DEG N)     11.7  11.8  11.9  12.0  12.0  11.9  11.7  12.2  13.8  16.4  19.0  21.5  23.8
LONG(DEG W)     20.3  21.5  22.6  23.9  25.2  27.8  30.0  31.6  33.2  35.4  37.8  40.4  42.4
STM SPEED (KT)    12    11    12    13    13    12     9     9    14    17    18    16    14
HEAT CONTENT      10     6     4     2     1     3     4     2     0     0     0     0     2

  FORECAST TRACK FROM BAMM      INITIAL HEADING/SPEED (DEG/KT):275/ 12      CX,CY: -11/  1
  T-12 MAX WIND:  25            PRESSURE OF STEERING LEVEL (MB):  509  (MEAN=625)
  GOES IR BRIGHTNESS TEMP. STD DEV. 100-300 KM RAD: -99.0 (MEAN=20.0)
  % GOES IR PIXELS WITH T < -20 C    50-200 KM RAD: -99.0 (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.   3.   7.  12.  16.  19.  21.  23.  24.
  VERTICAL SHEAR         1.   2.   3.   4.   6.   8.   8.  10.  11.  11.  11.  10.
  PERSISTENCE            0.  -1.  -1.  -1.  -1.  -1.  -1.  -1.  -1.  -1.   0.   0.
  200/250 MB TEMP.       0.   0.   0.   0.   0.   0.  -1.  -1.  -1.  -1.   0.   0.
  THETA_E EXCESS        -1.  -1.  -2.  -3.  -3.  -5.  -6.  -8. -11. -13. -14. -15.
  700-500 MB RH          0.   0.   0.   0.   0.   0.   0.   0.   0.  -1.  -2.  -3.
  GFS VORTEX TENDENCY    0.   0.   1.   2.   2.   4.   6.   7.   7.   5.   5.   6.
  850 MB ENV VORTICITY   0.   1.   1.   2.   3.   5.   7.   8.   9.  10.  10.   9.
  200 MB DIVERGENCE      0.   1.   2.   4.   6.   8.  10.  12.  13.  13.  12.  11.
  ZONAL STORM MOTION     0.   0.   1.   1.   1.   2.   2.   3.   3.   3.   4.   4.
  STEERING LEVEL PRES    0.   1.   1.   1.   1.   2.   2.   3.   3.   2.   2.   2.
  DAYS FROM CLIM. PEAK   0.   0.   0.  -1.  -1.  -2.  -2.  -2.  -3.  -3.  -3.  -4.
                        ----------------------------------------------------------
  SUB-TOTAL CHANGE       2.   5.  10.  14.  23.  34.  46.  56.  60.  61.  60.  58.

  SATELLITE ADJUSTMENTS ----------------------------------------------------------
  MEAN ADJUSTMENT        0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.
  GOES IR STD DEV        0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.
  GOES IR PIXEL COUNT    0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.
  OCEAN HEAT CONTENT     0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.
                        ----------------------------------------------------------
  TOTAL ADJUSTMENT       0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.
                        ----------------------------------------------------------
  TOTAL CHANGE (KT)      2.   5.  10.  14.  23.  34.  46.  56.  60.  61.  60.  58.

   ** 2008 ATLANTIC RI INDEX AL922008     INVEST 07/02/08  06 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) :   8.5 Range: 35.1 to   3.2 Scaled/Wgted Val:  0.8/  1.3
 D200 (10**7s-1)       : 103.0 Range:-20.0 to 149.0 Scaled/Wgted Val:  0.7/  1.1
 POT = MPI-VMAX (KT)   :  96.3 Range: 25.1 to 130.7 Scaled/Wgted Val:  0.7/  0.8
 850-700 MB REL HUM (%):  75.6 Range: 56.0 to  88.0 Scaled/Wgted Val:  0.6/  0.3
 % area w/pixels <-30 C:9999.0 Range: 17.0 to 100.0 Scaled/Wgted Val:999.0/999.0
 STD DEV OF IR BR TEMP : 999.9 Range: 35.1 to   3.2 Scaled/Wgted Val:999.0/999.0
 Heat content (KJ/cm2) :   4.6 Range:  0.0 to 132.0 Scaled/Wgted Val:  0.0/  0.0
 
 Prob of RI for 25 kt RI threshold=   999% is 999.0 times the sample mean(12.3%)
 Prob of RI for 30 kt RI threshold=   999% is 999.0 times the sample mean( 7.8%)
 Prob of RI for 35 kt RI threshold=   999

[KWT]

Hmm so SHIPS still forecasting a hurricane then as well, very interesting.

Do you have a link to that table cycloneye?

[cycloneye]

FINNALLY!! GFDL throws its first plots for 92L.


WHXX04 KWBC 021133
CHGQLM
ATTENTION...NATIONAL HURRICANE CENTER

NCEP COUPLED GFDL HURRICANE MODEL FORECAST MADE FOR

TROPICAL DEPRESSION INVEST 92L

INITIAL TIME 6Z JUL 2

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 12.0 19.9 275./12.0
6 11.5 21.3 250./15.5
12 11.3 22.2 257./ 8.5
18 11.2 23.3 264./10.7
24 11.2 24.5 272./12.2
30 11.1 25.6 263./10.6
36 11.3 26.2 290./ 6.1
42 11.7 27.2 291./10.9
48 12.2 28.1 299./10.5
54 12.9 29.4 300./14.2
60 13.6 30.6 299./13.4
66 14.8 31.7 317./15.7
72 16.0 33.2 309./19.0
78 17.2 35.1 302./21.4
84 17.9 37.0 289./19.6
90 18.5 38.6 292./16.8
96 19.3 40.2 298./16.7
102 20.1 41.8 296./17.7
108 20.9 43.4 296./16.7
114 21.6 44.7 299./13.9
120 22.6 45.8 311./13.6
126 23.4 46.4 324./10.0

[Eyewall]

Still not in agreement with all this north west turn junk by the models.

[Derek Ortt]

why is the turn to the NW junk?

[HURAKAN]

Where are the GFDL runs for 92L? I haven't seen one posted yet on any of the model sites.

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

[KWT]

Looks like a fairly decent starting point from the GFDL as well looking at the data we have so thats good to know.

so WNW generally with spells to the NW. Should stay well out to sea if thats the case though I do think the models are being a little too agressive with the right turn, I favor a more WNW track then a slight bend back to the west followed by a stronger NW turn by about 180hrs.

Also shows a weakening occuring as it travels through lower SST's as well very nicely.

[Eyewall]

It is junk because the models are acting like we are in the heart of the hurricane season showing this system growing into a huricane in no time when we all know that it is not possible for early July way out in the Atlantic. Even in 05 we never saw a system become a hurricane that far out in the Atlantic and that was one the the worst seasons on record.

[Category 5]

It is junk because the models are acting like we are in the heart of the hurricane season showing this system growing into a huricane in no time when we all know that is not possible for early July way out in the Atlantic. Even in 05 we never saw a system become a hurricane that far out in the Atlantic and that was one the the worst seasons on record.

Never say that.

[Eyewall]

How about looking at it this way 05 was a season of history of thing we never saw before. So this season might be another season of things we never have seen happen before in the Atlantic.

[cycloneye]

Moving more slowly now at 9kts.

818
WHXX01 KWBC 021225
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1225 UTC WED JUL 2 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 (AL922008) 20080702 1200 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
080702 1200 080703 0000 080703 1200 080704 0000

LAT LON LAT LON LAT LON LAT LON
BAMS 12.0N 20.4W 12.3N 23.2W 12.2N 26.4W 11.6N 29.4W
BAMD 12.0N 20.4W 12.4N 23.1W 12.6N 26.0W 12.7N 28.7W
BAMM 12.0N 20.4W 12.4N 23.1W 12.6N 26.1W 12.5N 29.0W
LBAR 12.0N 20.4W 12.2N 22.8W 12.6N 25.5W 13.1N 28.4W
SHIP 25KTS 31KTS 41KTS 51KTS
DSHP 25KTS 31KTS 41KTS 51KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
080704 1200 080705 1200 080706 1200 080707 1200

LAT LON LAT LON LAT LON LAT LON
BAMS 11.0N 31.7W 13.3N 34.3W 18.7N 39.3W 23.6N 44.7W
BAMD 12.8N 31.2W 14.8N 36.0W 19.0N 41.6W 23.9N 45.1W
BAMM 12.3N 31.4W 14.8N 35.3W 19.6N 40.6W 24.1N 45.2W
LBAR 13.6N 31.5W 15.2N 38.3W 19.1N 43.6W 22.9N 46.9W
SHIP 65KTS 80KTS 87KTS 83KTS
DSHP 65KTS 80KTS 87KTS 83KTS

...INITIAL CONDITIONS...
LATCUR = 12.0N LONCUR = 20.4W DIRCUR = 280DEG SPDCUR = 9KT
LATM12 = 11.7N LONM12 = 18.6W DIRM12 = 280DEG SPDM12 = 9KT
LATM24 = 11.4N LONM24 = 16.5W
WNDCUR = 25KT RMAXWD = 60NM WNDM12 = 25KT
CENPRS = 1009MB OUTPRS = 1012MB OUTRAD = 120NM SDEPTH = M
RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM

[KWT]

Thats very interesting cycloneye given wxman57 has a totally different fix, these systems when they form do bring up a lot of uncertainty.

Still the BAM models prog this system to head NW eventually, though of coursing they will only be using current synoptics and extrap them further out so we don't really know what will occur but they are in fairly decent agreement.

Also SHIPS takes this upto category 2 hurricane. I strongly suspect of course that they are strongly overdoing the strength however.