Tropical Storm Bertha Model Runs

[storms in NC]

I am hoping it will stay a weak TS and hit NC as a depression or storm because we REALLY need the rain.

I understand that the area is having fires around the state.

Yes, there have been several large fires around the area. One of them had most of the state covered in smoke for about a week before the winds shifted and blew the smoke back out to sea. The grass in this area sounds like potato chips when you walk on it, and there are many trees losing their leaves already. It truly is getting bad, already worse than last year. I am really hoping for a weak TS to come and give us some much needed rain.

I know the old saying watch what you wish for. I am very very sorry I really have to do this but I wish and Pray for rain. and I hope that Bertha Comes back to see us once again. We really could use the rain. But with all this high's sitting on top of us most of the time I don't see her comeing our way. What a shame.
Everyone is loseing their crops corn etc.. Not looking good here in the south

Oh and Hello Every one I am back once again
Deb

[Recurve]

Welcome back Deb. Hopefully a wave of strong troughs will bring you rain and protect Florida from canes.
The models were suggesting a strong trough will affect Bertha but I haven't kept up with the latest runs. I hope you get rain either way.
Just shows, life can't all be highs.

[Aric Dunn]

here is the loop including the 21z nhc track

[cycloneye]

A little more west shows this 18z run but mantains the turn more NW to north.Stalls some,but resumes the northward track.

18z GFS Loop

[cycloneye]

18z GFDL:

WHXX04 KWBC 032332
CHGQLM
ATTENTION...NATIONAL HURRICANE CENTER

NCEP COUPLED GFDL HURRICANE MODEL FORECAST MADE FOR

TROPICAL STORM BERTHA 02L

INITIAL TIME 18Z JUL 3

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 13.3 25.1 285./ 9.9
6 13.8 26.5 289./14.4
12 13.9 28.0 274./14.3
18 14.3 29.4 288./14.7
24 15.3 31.0 301./18.6
30 15.9 33.2 286./21.9
36 16.1 35.2 275./19.1
42 16.3 37.2 276./18.9
48 16.5 39.1 276./19.0
54 16.9 40.9 280./17.4
60 17.4 42.8 285./18.7
66 18.1 44.9 290./21.1
72 18.8 46.6 292./18.2
78 19.5 48.0 298./14.6
84 20.4 49.3 304./15.2
90 21.3 50.3 311./12.9
96 22.0 51.2 308./11.1
102 22.8 51.7 326./ 8.7
108 23.8 52.4 328./11.6
114 24.8 52.9 332./11.3
120 25.6 53.6 322./10.1
126 26.4 53.9 339./ 8.0

[KWT]

Still racing it W/WNW after 30hrs isn't it, foward speed progged to reach 20kts, I'd be surprised if it gets that fast to be honest, 15kts maybe.

Also turn to the NW still occurs at the end of the run.

[Ivanhater]

[cycloneye]

Now lets see if GFDL mantains what it had at the 12z run,and that was a 85kt hurricane.

[Eyewall]

I've seen a few posts saying that a NW and N turn that the GFS shows will be imposible.
I'd like to respectfully disagree. Heres my reasoning:

At 54hrs there is a sfc low causing a break in the high, even a weak tropical storm would react to this IMO:


At 90hrs yes, the high is much stronger and the storm stalls:


But at 144hrs the bermuda high is much weaker and a trough is along the east coast, bye bye Bertha:


Disclaimer: this is not endorsed by storm2k and is solely the opinion of the poster

[gatorcane]

Eyewall yes you could be right but two issues:

1) The GFS Western Atlantic trough/ridge prediction is 144+ hours out. Accuracy beyond 144 hours is especially inaccurate.
2) If Bertha's vertical structure remains below the mid-levels (in other words does not deepen into a hurricane) it is likely to
just head WNW for quite sometime albeit as a weak system or wave.

[storms in NC]

The way the weather pattern has been I think most will go out to sea this early till we see a change. But if it is any thing like it has been for the few years the pattern don't change much. It would have to be a home grown storm to hit any where in the states. Now the Islands might have to keep a eye out more so then the US. This is just my two cents.

[Gustywind]

The way the weather pattern has been I think most will go out to sea this early till we see a change. But if it is any thing like it has been for the few years the pattern don't change much. It would have to be a home grown storm to hit any where in the states. Now the Islands might have to keep a eye out more so then the US. This is just my two cents.

Yeah interresting point of view, this is my gut feeling too, hope Bertha will move away of us, but as usual we keep watching it in case of , Cycloneye knew that too...Herbert Box

[cycloneye]

18z HWRF shows a moderate tropical storm moving WNW tracking thru 20n-50w.

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

[cycloneye]

Up to 40 kts.


WHXX01 KWBC 040049
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0049 UTC FRI JUL 4 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) 20080704 0000 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
080704 0000 080704 1200 080705 0000 080705 1200

LAT LON LAT LON LAT LON LAT LON
BAMS 13.3N 26.3W 14.6N 29.6W 15.8N 32.9W 17.0N 36.5W
BAMD 13.3N 26.3W 14.5N 28.8W 15.9N 31.6W 17.4N 34.7W
BAMM 13.3N 26.3W 14.8N 29.1W 16.5N 32.2W 18.0N 35.8W
LBAR 13.3N 26.3W 14.0N 28.9W 15.3N 32.0W 16.7N 35.4W
SHIP 40KTS 47KTS 54KTS 61KTS
DSHP 40KTS 47KTS 54KTS 61KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
080706 0000 080707 0000 080708 0000 080709 0000

LAT LON LAT LON LAT LON LAT LON
BAMS 18.0N 40.2W 20.0N 47.8W 21.0N 53.5W 21.5N 56.0W
BAMD 18.7N 37.9W 21.6N 44.0W 24.9N 47.4W 28.1N 47.5W
BAMM 19.1N 39.7W 21.0N 47.3W 22.6N 51.8W 24.1N 53.5W
LBAR 18.2N 38.7W 21.8N 44.4W 22.1N 51.0W 24.7N 52.7W
SHIP 64KTS 73KTS 75KTS 67KTS
DSHP 64KTS 73KTS 75KTS 67KTS

...INITIAL CONDITIONS...
LATCUR = 13.3N LONCUR = 26.3W DIRCUR = 275DEG SPDCUR = 11KT
LATM12 = 13.1N LONM12 = 24.0W DIRM12 = 283DEG SPDM12 = 11KT
LATM24 = 12.3N LONM24 = 21.8W
WNDCUR = 40KT RMAXWD = 30NM WNDM12 = 35KT
CENPRS = 1006MB OUTPRS = 1012MB OUTRAD = 170NM SDEPTH = M
RD34NE = 30NM RD34SE = 30NM RD34SW = 0NM RD34NW = 30NM

$$
NNNN

[Ivanhater]

Steady trend westward throughout the day..let's see what happens in tonights run...

[cycloneye]

00.00 UTC Ships forecast.30kt shear at 120 hours.

Code: Select all

                  *   ATLANTIC SHIPS INTENSITY FORECAST       *
                    *        GOES/OHC INPUT INCLUDED            *
                    *      BERTHA  AL022008  07/04/08  00 UTC   *

TIME (HR)          0     6    12    18    24    36    48    60    72    84    96   108   120
V (KT) NO LAND    40    43    47    50    54    61    64    69    73    76    75    72    67
V (KT) LAND       40    43    47    50    54    61    64    69    73    76    75    72    67
V (KT) LGE mod    40    42    45    47    50    55    60    66    71    73    74    72    68

SHEAR (KTS)        5     6     7     6     9     1     7     7     8    15    15    23    30
SHEAR DIR        274   259   217   178   216   189   133   221   221   273   228   237   224
SST (C)         25.6  25.7  25.6  25.2  24.9  25.1  25.4  25.8  26.1  26.7  27.1  27.1  27.1
POT. INT. (KT)   111   113   112   109   107   109   111   114   116   122   126   126   126
ADJ. POT. INT.   108   111   110   108   105   106   108   111   111   114   116   114   112
200 MB T (C)   -53.9 -54.3 -54.0 -53.4 -53.9 -54.4 -53.7 -54.1 -53.8 -54.1 -53.6 -53.8 -53.8
TH_E DEV (C)       4     5     4     5     4     5     5     6     7     7     8     8     9
700-500 MB RH     78    75    73    72    71    58    55    56    53    49    51    51    47
GFS VTEX (KT)     16    17    18    18    20    19    17    17    17    20    20    20    20
850 MB ENV VOR    75    73    76    89   108   119   111    96    73    53    26    23     1
200 MB DIV        63    62    20    46    76    32    32    25    71    45    33    30    -2
LAND (KM)        963  1111  1262  1435  1610  1986  1915  1769  1697  1697  1643  1548  1520
LAT (DEG N)     13.3  13.7  14.0  14.5  15.0  16.0  16.8  17.8  18.9  20.2  21.8  23.6  25.4
LONG(DEG W)     26.3  27.8  29.2  30.9  32.5  36.0  39.5  42.9  46.0  48.5  50.4  51.9  53.1
STM SPEED (KT)    13    15    16    17    17    17    17    17    15    12    12    11    11
HEAT CONTENT       0     0     0     0     0     0     0     0     2    11    14    14    12

  FORECAST TRACK FROM OFCI      INITIAL HEADING/SPEED (DEG/KT):275/ 11      CX,CY: -10/  1
  T-12 MAX WIND:  35            PRESSURE OF STEERING LEVEL (MB):  563  (MEAN=625)
  GOES IR BRIGHTNESS TEMP. STD DEV. 100-300 KM RAD:  19.8 (MEAN=20.0)
  % GOES IR PIXELS WITH T < -20 C    50-200 KM RAD:  60.0 (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.   0.   0.   2.   4.   6.   8.   9.  10.  11.
  VERTICAL SHEAR         1.   2.   3.   4.   7.   9.  11.  12.  11.  11.   9.   6.
  PERSISTENCE            1.   1.   2.   2.   2.   2.   2.   2.   2.   1.   1.   0.
  200/250 MB TEMP.       0.   0.   0.   0.   1.   1.   1.   1.   1.   2.   2.   2.
  THETA_E EXCESS         0.  -1.  -2.  -2.  -3.  -4.  -6.  -7.  -9. -10. -10. -11.
  700-500 MB RH          0.   0.   0.   0.   0.   0.   0.   0.   0.   0.  -1.  -1.
  GFS VORTEX TENDENCY    0.   0.   0.   2.   1.  -1.   0.   0.   2.   1.   1.   1.
  850 MB ENV VORTICITY   0.   1.   1.   2.   3.   4.   5.   6.   6.   6.   5.   5.
  200 MB DIVERGENCE      0.   0.   1.   1.   2.   2.   3.   4.   4.   4.   4.   4.
  ZONAL STORM MOTION     0.   0.   0.   1.   1.   2.   2.   2.   2.   3.   3.   3.
  STEERING LEVEL PRES    0.   0.   0.   0.   1.   1.   1.   1.   1.   1.   1.   1.
  DAYS FROM CLIM. PEAK   0.   0.   0.  -1.  -1.  -2.  -2.  -2.  -3.  -3.  -3.  -4.
                        ----------------------------------------------------------
  SUB-TOTAL CHANGE       3.   6.  10.  14.  21.  24.  30.  34.  37.  37.  34.  29.

  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.   0.   0.   0.   0.   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.   0.   0.   0.  -1.  -1.  -2.  -2.  -2.  -2.
                        ----------------------------------------------------------
  TOTAL CHANGE (KT)      3.   7.  10.  14.  21.  24.  29.  33.  36.  35.  32.  27.

   ** 2008 ATLANTIC RI INDEX AL022008     BERTHA 07/04/08  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:  0.7/  1.2
 850-200 MB SHEAR (KT) :   6.7 Range: 35.1 to   3.2 Scaled/Wgted Val:  0.9/  1.4
 D200 (10**7s-1)       :  53.4 Range:-20.0 to 149.0 Scaled/Wgted Val:  0.4/  0.6
 POT = MPI-VMAX (KT)   :  68.4 Range: 25.1 to 130.7 Scaled/Wgted Val:  0.4/  0.5
 850-700 MB REL HUM (%):  77.8 Range: 56.0 to  88.0 Scaled/Wgted Val:  0.7/  0.3
 % area w/pixels <-30 C:  48.0 Range: 17.0 to 100.0 Scaled/Wgted Val:  0.4/  0.1
 STD DEV OF IR BR TEMP :  18.1 Range: 35.1 to   3.2 Scaled/Wgted Val:  0.5/  0.7
 Heat content (KJ/cm2) :   0.0 Range:  0.0 to 132.0 Scaled/Wgted Val:  0.0/  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=     3% is   0.3 times the sample mean( 7.8%)
 Prob of RI for 35 kt RI threshold=     1% is   0.3 times the sample mean( 4.5%)

   ##         ANNULAR HURRICANE INDEX (AHI) AL022008     BERTHA 07/04/08  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

[vacanechaser]

here is the loop including the 21z nhc track

nice job there mr. dunn... they have certainly shifted westward and starting to flatten out some... i am starting to have the feeling she is coming across.... dont know if she is gonna make landfall, but certainly looking like a long tracker to start the season.. just like '96's bertha...




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

[brunota2003]

SHIPS starting to back off on the shear some? Interesting, considering she should be entering warmer waters then, too. Trend? We'll have to see.

[cycloneye]

Code: Select all

SST (C)         25.6  25.7  25.6  25.2  24.9  25.1  25.4  25.8  26.1  26.7  27.1  27.1  27.1

SHIP forecast for ssts.

[Extremeweatherguy]

I'm not liking that westward model trend. If it continues, then the SE coast of the U.S., the NE islands, and Bermuda may need to watch Bertha a bit more closely.