Tropical Storm Bertha Model Runs

[z1z2]

through 174 hours the 00z GFS has surprisingly shifted back west to be more inline with the NHC.

[cycloneye]

The 00z GFS is more west and moves slowly WNW after 120 hours.After 174 hours,it goes north close to Bermuda.

http://www.nco.ncep.noaa.gov/pmb/nwprod ... loop.shtml

[NDG]

Oh Boy, 00z GFS fairly much stalls out or mover Bertha very little once she reaches the area between Bermuda and P.R. near the 25th lat and 65th long for at least 2 to 3 days.

[Derek Ortt]

The G-IV flies out of Tampa, not Keesler

I know that the HHers relocate to STX for the long trackers - do the G IVs do something similar, or do they use their speed to strike from Tampa?

The G-IV usually flies from Tampa

[ekal]

A big shift west from the CMC at 00z, with a close pass at the islands.

http://moe.met.fsu.edu/cgi-bin/cmctc2.c ... =Animation

[NDG]

For what is worth the CMC runs have been trending westward on its runs.

[Ed Mahmoud]

Everyone knows the CMC is development happy. Anybody know (I'm sure it has been checked) how CMC does on track guidance for pre-existing TCs?


For exisitng cyclones, which model verifies best the last few seasons?

[Ed Mahmoud]

Canadian still shows a recurve at the end short of land, although too close for comfort in NE Caribbean.

[ROCK]

Everyone knows the CMC is development happy. Anybody know (I'm sure it has been checked) how CMC does on track guidance for pre-existing TCs?


For exisitng cyclones, which model verifies best the last few seasons?

For existing, I tend to go with the EURO for track purposes. Last year with Dean and Felix made me a believer....

[ekal]

00z UKMET continues with its westerly track, although it depicts an open wave once the system reaches the longitude of the Northern Leewards.

http://moe.met.fsu.edu/cgi-bin/ukmtc2.c ... =Animation

[LarryWx]

Everyone knows the CMC is development happy. Anybody know (I'm sure it has been checked) how CMC does on track guidance for pre-existing TCs?


For exisitng cyclones, which model verifies best the last few seasons?

The CMC was horrible relative to other dynamic models per p. 25 of the study found at the following link for 2006 data:

http://www.nhc.noaa.gov/verification/pd ... n_2006.pdf

Average 120 hour errors (nautical miles) for 2006 Atlantic storms (based on 22 cases...pretty good sample size):

ECMWF: 163
GFDL: 234
GFS: 250
NOGAPS: 250
UKMET: 296
CMC: 463

So, the 120 hour CMC error was nearly three times the Euro error!!

Also, the EC@96/120 was better than others@72/96 & CMC@48/72!

[Chacor]

Table/graph of 06z intensity models.

Code: Select all

Model/T    INIT   12    24    36    48    60    72    84    96   108   120
AVNI        45    45    48    55    54    51    47    49    49    46    45
GFDI        45    45    52    52    49    53    53    56    67    81    96
GFNI        45    36    35    36    39    43    52    57    59    69    79
HWFI        45    50    50    54    60    64    72    74    74    72    70
IVCN        45    46    49    53    56    60    64    66    69    74    79
LGEM        45    48    53    60    66    71    73    73    74    76    78
NGPI        45    44    46    49    52    50    47    47    47    49    50
SHIP        45    49    56    64    67    70    70    72    73    75    75


Refer to ftp://ftp.tpc.ncep.noaa.gov/atcf/nhc_techlist.dat for model names.

[SouthFloridawx]

[Steve]

The key to each of those globals seems to be based on their depiction of the strength and size of the next surface high coming down from Canada. - something to watch and see how that airmass evolves and what affect it has (stall, loop, block, catch or deflect) and how the global models saw it. There would be a calendar adjustment for early july but maybe some clues on down the road for later this season too...

Steve

[ronjon]

This mornings model runs shed a little more light on the future track of Bertha but still some uncertainty after 5 days. The GFS, GFDL, ECM, CMC, & NOGAPs all in amazing agreement to bring the storm to about 25N-65W or there abouts in 5 days. They all stall or slow the storm as it recurves northward around the 65W line as the storm appears to get trapped under a rebuilding Atlantic ridge. The key will be how strong the ridge rebuilds, how long, and if there is another trough to weaken it after a couple of days as the GFS and Euro now suggest. Two outliers, the UKMET and NAM, diminish Bertha into an open wave that stays south and heads toward the Bahamas.

[Meso]

For interesting sake here in the long range CMC at 192 hours



Still makes it out to sea

[storms in NC]

I have said all along it would curve's out to sea. Right now it is under the ridge and then around day 4-5 it will start to recurved from a weakness in the ridge on out to sea. But may come close to Bermuda.
I think Monday will tell all if not Tuesday.

[cycloneye]

Moving west at 275 degrees.

WHXX01 KWBC 061240
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1240 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 1200 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
080706 1200 080707 0000 080707 1200 080708 0000

LAT LON LAT LON LAT LON LAT LON
BAMS 17.2N 44.2W 18.2N 48.0W 19.1N 51.4W 19.7N 54.2W
BAMD 17.2N 44.2W 18.4N 47.3W 19.6N 49.6W 20.6N 51.1W
BAMM 17.2N 44.2W 18.3N 47.7W 19.3N 50.3W 20.1N 52.1W
LBAR 17.2N 44.2W 18.1N 47.6W 19.1N 50.7W 20.0N 53.4W
SHIP 45KTS 48KTS 54KTS 61KTS
DSHP 45KTS 48KTS 54KTS 61KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
080708 1200 080709 1200 080710 1200 080711 1200

LAT LON LAT LON LAT LON LAT LON
BAMS 20.2N 56.8W 22.0N 61.2W 24.4N 64.3W 26.3N 65.4W
BAMD 21.4N 52.1W 23.5N 54.0W 25.6N 55.1W 26.4N 55.3W
BAMM 20.8N 53.7W 22.7N 56.5W 25.1N 58.6W 26.4N 59.7W
LBAR 20.8N 55.7W 23.4N 59.3W 26.5N 61.5W 27.8N 61.6W
SHIP 62KTS 64KTS 66KTS 70KTS
DSHP 62KTS 64KTS 66KTS 70KTS

...INITIAL CONDITIONS...
LATCUR = 17.2N LONCUR = 44.2W DIRCUR = 275DEG SPDCUR = 18KT
LATM12 = 16.8N LONM12 = 40.3W DIRM12 = 277DEG SPDM12 = 19KT
LATM24 = 16.4N LONM24 = 36.4W
WNDCUR = 45KT RMAXWD = 30NM WNDM12 = 45KT
CENPRS = 1000MB OUTPRS = 1012MB OUTRAD = 180NM SDEPTH = D
RD34NE = 75NM RD34SE = 30NM RD34SW = 0NM RD34NW = 75NM

$$

[cycloneye]

SHIP 12:00 UTC forecast: Shear will not be a major problem according to this 12 UTC forecast.

Code: Select all

              *   ATLANTIC SHIPS INTENSITY FORECAST       *
                    *        GOES/OHC INPUT INCLUDED            *
                    *      BERTHA  AL022008  07/06/08  12 UTC   *

TIME (HR)          0     6    12    18    24    36    48    60    72    84    96   108   120
V (KT) NO LAND    45    46    48    51    54    61    62    65    64    65    66    70    70
V (KT) LAND       45    46    48    51    54    61    62    65    64    65    66    70    70
V (KT) LGE mod    45    46    47    49    51    57    61    65    66    66    67    70    74

SHEAR (KTS)        9     7    10    10     9    13    20    13    21    13    16     3    13
SHEAR DIR        226   219   210   233   243   227   276   239   260   245   274   350    45
SST (C)         26.0  26.1  26.3  26.6  27.0  27.5  27.9  27.9  27.9  28.0  28.0  28.0  27.8
POT. INT. (KT)   117   117   119   122   126   131   136   136   136   136   136   137   135
ADJ. POT. INT.   115   114   116   118   121   124   129   127   125   123   122   123   120
200 MB T (C)   -54.7 -54.5 -54.3 -54.6 -54.8 -54.5 -54.9 -55.0 -55.5 -55.4 -55.6 -55.5 -55.4
TH_E DEV (C)       8     8     9     9    10    10     9    10    10    11    10    11    10
700-500 MB RH     47    46    48    46    43    41    45    47    49    45    44    45    49
GFS VTEX (KT)     12    11    11    12    13    14    13    11    10     8     8     7     7
850 MB ENV VOR    76    57    59    57    54    34    22    12   -24   -40   -64   -72   -42
200 MB DIV        27    42    51    42    40    15    -6   -10     6    -1    -3    -4    -1
LAND (KM)       1632  1566  1519  1493  1394  1252  1022   813   691   651   680   762   871
LAT (DEG N)     17.2  17.6  17.9  18.4  18.8  19.6  20.4  21.5  22.7  23.7  24.5  25.8  27.4
LONG(DEG W)     44.2  46.0  47.7  49.4  51.0  53.7  56.2  58.7  61.0  63.1  64.7  66.5  68.3
STM SPEED (KT)    18    17    17    16    15    13    13    12    12     9     9    11    11
HEAT CONTENT       0     2     6    14    21    31    42    37    29    29    31    27    22

  FORECAST TRACK FROM OFCI      INITIAL HEADING/SPEED (DEG/KT):275/ 18      CX,CY: -17/  2
  T-12 MAX WIND:  45            PRESSURE OF STEERING LEVEL (MB):  651  (MEAN=625)
  GOES IR BRIGHTNESS TEMP. STD DEV. 100-300 KM RAD:  23.6 (MEAN=20.0)
  % GOES IR PIXELS WITH T < -20 C    50-200 KM RAD:  51.0 (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.   9.  11.  12.  12.  12.
  VERTICAL SHEAR         1.   1.   2.   3.   4.   4.   4.   2.   2.   2.   4.   4.
  PERSISTENCE            0.  -1.  -1.  -1.  -1.  -1.  -1.  -1.  -1.  -1.   0.   0.
  200/250 MB TEMP.       0.   0.   1.   1.   1.   2.   3.   3.   4.   5.   6.   7.
  THETA_E EXCESS         0.   0.   0.  -1.  -1.  -1.  -1.  -2.  -2.  -2.  -2.  -3.
  700-500 MB RH          0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.
  GFS VORTEX TENDENCY    0.   0.   0.   0.   1.  -1.  -2.  -3.  -5.  -5.  -6.  -6.
  850 MB ENV VORTICITY   0.   1.   1.   1.   1.   1.   1.   1.   0.  -1.  -2.  -3.
  200 MB DIVERGENCE      0.   0.   1.   1.   1.   0.   0.  -1.  -1.  -1.  -1.  -2.
  ZONAL STORM MOTION     0.   0.   1.   1.   3.   3.   4.   5.   5.   6.   8.   8.
  STEERING LEVEL PRES    0.   0.   0.   0.   0.  -1.  -1.  -1.  -1.  -1.  -1.  -1.
  DAYS FROM CLIM. PEAK   0.   0.   0.  -1.  -1.  -2.  -2.  -2.  -2.  -3.  -3.  -4.
                        ----------------------------------------------------------
  SUB-TOTAL CHANGE       2.   4.   7.  10.  17.  18.  21.  21.  22.  23.  26.  27.

  SATELLITE ADJUSTMENTS ----------------------------------------------------------
  MEAN ADJUSTMENT        0.   0.   0.   0.  -1.  -1.  -1.  -1.  -1.  -1.  -1.  -2.
  GOES IR STD DEV        0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.
  GOES IR PIXEL COUNT    0.   0.  -1.  -1.  -1.  -1.   0.   0.   1.   1.   1.   0.
  OCEAN HEAT CONTENT     0.   0.   0.   0.   0.   0.  -1.  -1.  -1.  -1.  -1.  -1.
                        ----------------------------------------------------------
  TOTAL ADJUSTMENT       0.   0.  -1.  -1.  -1.  -1.  -1.  -1.  -1.  -1.  -1.  -2.
                        ----------------------------------------------------------
  TOTAL CHANGE (KT)      1.   3.   6.   9.  16.  17.  20.  20.  20.  21.  25.  25.

   ** 2008 ATLANTIC RI INDEX AL022008     BERTHA 07/06/08  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) :   9.1 Range: 35.1 to   3.2 Scaled/Wgted Val:  0.8/  1.3
 D200 (10**7s-1)       :  40.4 Range:-20.0 to 149.0 Scaled/Wgted Val:  0.4/  0.5
 POT = MPI-VMAX (KT)   :  71.9 Range: 25.1 to 130.7 Scaled/Wgted Val:  0.4/  0.5
 850-700 MB REL HUM (%):  63.6 Range: 56.0 to  88.0 Scaled/Wgted Val:  0.2/  0.1
 % area w/pixels <-30 C:  41.0 Range: 17.0 to 100.0 Scaled/Wgted Val:  0.3/  0.1
 STD DEV OF IR BR TEMP :  19.2 Range: 35.1 to   3.2 Scaled/Wgted Val:  0.5/  0.7
 Heat content (KJ/cm2) :   8.6 Range:  0.0 to 132.0 Scaled/Wgted Val:  0.1/  0.0
 
 Prob of RI for 25 kt RI threshold=    19% is   1.6 times the sample mean(12.3%)
 Prob of RI for 30 kt RI threshold=    13% is   1.7 times the sample mean( 7.8%)
 Prob of RI for 35 kt RI threshold=     7% is   1.6 times the sample mean( 4.5%)

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

[KWT]

Looking at the modelsm looks like its going to take the best route it can at that far west because its too far away from Bermuda to be a threat whilst its also looking more and more possible it will be to the east of the US when it finally lifts out.

Anyway SHIPS still going for hurricane and whilst shear does increase to 20kts its not totally destructive compared to the 35kts that was progged before.