Tropical Storm Fay Model Runs

[HURAKAN]

I agree...I can't tell you how many times I've seent the models obliterate or show a major threat to Florida and then it either goes into the Gulf or up to the Caronlinas. We shall see I guess.

I agree but you can also make the case on the opposite.

[caneman]

When the Euro and GFDL speak, I listen.

[hurricanefloyd5]

the models have dose a great job predicing a TC out up to 5-7 days out this year so far!!!!!!!!!

[gatorcane]

GFS is showing even a less amplified trough at day 10....which would suggest a blocking recurve pattern for 92L.

[Derek Ortt]

one problem... the model initial heading is wrong. The center is well to the south near 14N and i moving nearly due west. This one is likely to enter the Carib, not pass north of it

[cycloneye]

Pressure down to 1007 mbs.

WHXX01 KWBC 121309
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1309 UTC TUE AUG 12 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) 20080812 1200 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
080812 1200 080813 0000 080813 1200 080814 0000

LAT LON LAT LON LAT LON LAT LON
BAMS 15.5N 50.8W 17.0N 53.6W 18.7N 56.4W 20.3N 58.6W
BAMD 15.5N 50.8W 17.1N 52.9W 18.7N 54.9W 20.0N 56.6W
BAMM 15.5N 50.8W 16.9N 53.1W 18.5N 55.3W 19.8N 57.2W
LBAR 15.5N 50.8W 17.1N 52.7W 18.5N 54.7W 19.6N 56.8W
SHIP 25KTS 30KTS 36KTS 43KTS
DSHP 25KTS 30KTS 36KTS 43KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
080814 1200 080815 1200 080816 1200 080817 1200

LAT LON LAT LON LAT LON LAT LON
BAMS 21.3N 61.1W 22.5N 66.1W 22.9N 70.7W 23.2N 74.5W
BAMD 20.6N 58.3W 20.5N 61.7W 19.5N 64.8W 18.6N 68.0W
BAMM 20.6N 59.3W 21.4N 63.8W 21.5N 68.2W 22.1N 72.0W
LBAR 20.5N 58.9W 21.5N 63.4W 22.0N 68.2W 22.9N 71.8W
SHIP 50KTS 59KTS 64KTS 68KTS
DSHP 50KTS 59KTS 64KTS 68KTS

...INITIAL CONDITIONS...
LATCUR = 15.5N LONCUR = 50.8W DIRCUR = 305DEG SPDCUR = 12KT
LATM12 = 13.8N LONM12 = 48.5W DIRM12 = 316DEG SPDM12 = 15KT
LATM24 = 11.9N LONM24 = 47.3W
WNDCUR = 25KT RMAXWD = 60NM WNDM12 = 25KT
CENPRS = 1007MB OUTPRS = 1011MB OUTRAD = 180NM SDEPTH = M
RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM

[gatorcane]

one problem... the model initial heading is wrong. The center is well to the south near 14N and i moving nearly due west. This one is likely to enter the Carib, not pass north of it

ah but its a weak "center" and a new one could be under the deeper convection that is shearing off to the NE, that is the problem. If the center develops north of 15N then its not likely it is a Caribbean storm based on 150 years of climatology in this area. GFS 500mb flow shows a small weakness NW of 92L due to the UL trough which could allow a NW movement and then the weakness quickly fills in within 12-24 hours with dominant East to West flow which would bend it back nearly due west.

Members can see the "weakness" and UL trough I mention in this WV image. Note the circular area NNW of 92L (aka the ULL or TUTT) and imagine a trough axis extending SW from that. Wind flow is SW E of the axis and nearly due E W of the axis. Once 92L crosses the axis the UL environment becomes very favorable for development.

[cycloneye]

[cycloneye]

SHIP 12:00 UTC forecast. Shear not a big problem.

Code: Select all

ATLANTIC SHIPS INTENSITY FORECAST       *
                    *        GOES/OHC INPUT INCLUDED            *
                    *      INVEST  AL922008  08/12/08  12 UTC   *

TIME (HR)          0     6    12    18    24    36    48    60    72    84    96   108   120
V (KT) NO LAND    25    28    30    33    36    43    50    54    59    61    64    67    68
V (KT) LAND       25    28    30    33    36    43    50    54    59    61    64    67    68
V (KT) LGE mod    25    26    27    28    29    33    39    44    49    53    57    62    67

SHEAR (KTS)        8    14    10     6     4     6    15    11    16    10    13     3     9
SHEAR DIR        178   206   219   246   265   252   289   293   314   322   324   245   284
SST (C)         28.0  28.1  28.2  28.3  28.3  28.4  28.3  28.3  28.5  28.8  29.0  28.9  28.9
POT. INT. (KT)   138   139   141   142   142   143   141   141   144   149   152   150   149
ADJ. POT. INT.   136   136   137   138   136   134   131   130   133   137   140   137   136
200 MB T (C)   -53.5 -53.1 -53.1 -53.4 -53.5 -52.9 -53.2 -53.2 -53.6 -53.4 -53.5 -53.1 -53.6
TH_E DEV (C)      10    11    11    10     9    10    10    11    10    11    10    11    10
700-500 MB RH     58    56    52    55    57    54    53    50    53    55    57    56    56
GFS VTEX (KT)     10    12    10    10    10     9     9     7     8     7     8     7     6
850 MB ENV VOR    48    39    35    30    25     4     7   -11    -7   -16    -9   -16   -25
200 MB DIV        32    36    38    22     0    -4    -4    -4    -7   -26    -7    -4    20
LAND (KM)       1143  1147  1088  1060  1052   908   717   553   395   344   265   219   252
LAT (DEG N)     15.5  16.2  16.9  17.7  18.5  19.8  20.6  21.2  21.4  21.6  21.5  21.7  22.1
LONG(DEG W)     50.8  52.0  53.1  54.2  55.3  57.2  59.3  61.4  63.8  66.0  68.2  70.1  72.0
STM SPEED (KT)    13    13    13    13    12    11    10    10    11    10    10     9     9
HEAT CONTENT      53    58    62    55    49    54    51    47    51    65    68    64    24

  FORECAST TRACK FROM BAMM      INITIAL HEADING/SPEED (DEG/KT):305/ 12      CX,CY:  -9/  7
  T-12 MAX WIND:  25            PRESSURE OF STEERING LEVEL (MB):  541  (MEAN=625)
  GOES IR BRIGHTNESS TEMP. STD DEV. 100-300 KM RAD:  27.0 (MEAN=20.0)
  % GOES IR PIXELS WITH T < -20 C    50-200 KM RAD:  61.0 (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.   1.   2.   5.  10.  16.  21.  26.  29.  32.  34.
  VERTICAL SHEAR         1.   2.   4.   5.   8.   9.   9.   8.   7.   7.   8.   8.
  PERSISTENCE            0.  -1.  -1.  -1.  -1.  -1.  -1.  -1.  -1.  -1.   0.   0.
  200/250 MB TEMP.       0.   0.   0.   0.  -1.  -1.  -1.  -1.  -1.  -1.   0.   0.
  THETA_E EXCESS         0.   0.   0.   0.   0.   0.  -1.  -1.  -1.  -1.  -1.  -1.
  700-500 MB RH          0.   0.   0.   0.   0.   0.   0.   0.   0.   0.  -1.  -1.
  GFS VORTEX TENDENCY    0.   0.   0.   0.  -1.  -1.  -3.  -2.  -3.  -3.  -4.  -4.
  850 MB ENV VORTICITY   0.   0.   0.   0.   0.   0.  -1.  -1.  -1.  -2.  -2.  -3.
  200 MB DIVERGENCE      0.   0.   0.   0.   0.  -1.  -1.  -2.  -2.  -3.  -3.  -3.
  ZONAL STORM MOTION     0.   0.   0.   1.   1.   1.   2.   2.   2.   2.   2.   2.
  STEERING LEVEL PRES    0.   0.   1.   1.   1.   1.   1.   2.   2.   2.   1.   1.
  DAYS FROM CLIM. PEAK   0.   0.   0.   0.   0.  -1.  -1.  -1.  -1.  -1.  -1.  -1.
                        ----------------------------------------------------------
  SUB-TOTAL CHANGE       2.   5.   7.  11.  18.  25.  30.  35.  38.  41.  44.  45.

  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.   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.   1.   1.   1.   1.   0.   0.  -1.  -2.  -2.  -2.  -2.
                        ----------------------------------------------------------
  TOTAL CHANGE (KT)      3.   5.   8.  11.  18.  25.  29.  34.  36.  39.  42.  43.

   ** 2008 ATLANTIC RI INDEX AL922008     INVEST 08/12/08  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) :   8.5 Range: 35.1 to   3.2 Scaled/Wgted Val:  0.8/  1.3
 D200 (10**7s-1)       :  25.6 Range:-20.0 to 149.0 Scaled/Wgted Val:  0.3/  0.4
 POT = MPI-VMAX (KT)   : 111.3 Range: 25.1 to 130.7 Scaled/Wgted Val:  0.8/  0.9
 850-700 MB REL HUM (%):  67.4 Range: 56.0 to  88.0 Scaled/Wgted Val:  0.4/  0.1
 % area w/pixels <-30 C:  53.0 Range: 17.0 to 100.0 Scaled/Wgted Val:  0.4/  0.1
 STD DEV OF IR BR TEMP :  19.3 Range: 35.1 to   3.2 Scaled/Wgted Val:  0.5/  0.6
 Heat content (KJ/cm2) :  55.4 Range:  0.0 to 132.0 Scaled/Wgted Val:  0.4/  0.0
 
 Prob of RI for 25 kt RI threshold=    23% is   1.8 times the sample mean(12.3%)
 Prob of RI for 30 kt RI threshold=    14% is   1.8 times the sample mean( 7.8%)
 Prob of RI for 35 kt RI threshold=     8% is   1.8 times the sample mean( 4.5%)

   ##         ANNULAR HURRICANE INDEX (AHI) AL922008     INVEST 08/12/08  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

[Ed Mahmoud]

Looking at PPV AccuWx graphics of 6Z GFDL, looks like 92L is going to just miss its connection to recurve. Hours 114 through 126 show weak steering, but it looks like the trough lifts out and the ridge builds back in, so if there really is a Cat 2 hurricane in the Bahamas, it will be moving slowly, but heading West.


No idea whether that is correct, of course.

[ronjon]

If it were only that easy to predict then we wouldn't need the NHC.
This won't even make it into the GOM in my opinion if it were to develop.

Stormcenter, try backing up your statement with some analysis and logic. This is a forum for opinions but it ususally helps to back them up with some scientific reasoning. I make my case based on the models - if they change, I'll certainly go along. It is 7 days out so things will change. But, the overall pattern argues for a west or W-NW movement not recurvature at this time.

[gatorcane]

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

I have a high degree of confidence 92L will develop looking at the models and synoptic setup. Now for all of you Florida watchers, the next 24-48 hours is key to where could end up going. As the models suggest, it should move generally WNW to NW then a bend to the west will happen. The bend to the west will make all of the difference as to where it ends up and how much lattitude it gains is going to be key.

Still very early as to where it goes and how strong it gets so the above thinking has a high degree of uncertainty.

[AtlanticWind]

one problem... the model initial heading is wrong. The center is well to the south near 14N and i moving nearly due west. This one is likely to enter the Carib, not pass north of it

ah but its a weak "center" and a new one could be under the deeper convection that is shearing off to the NE, that is the problem. If the center develops north of 15N then its not likely it is a Caribbean storm based on 150 years of climatology in this area. GFS 500mb flow shows a small weakness NW of 92L due to the UL trough which could allow a NW movement and then the weakness quickly fills in within 12-24 hours with dominant East to West flow which would bend it back nearly due west.

Members can see the "weakness" and UL trough I mention in this WV image. Note the circular area NNW of 92L (aka the ULL or TUTT) and imagine a trough axis extending SW from that. Wind flow is SW E of the axis and nearly due E W of the axis. Once 92L crosses the axis the UL environment becomes very favorable for development.

All Indications are that the center is above 15 north and moving Wnw as far as I see.

[Stormcenter]

the models have dose a great job predicing a TC out up to 5-7 days out this year so far!!!!!!!!!

It all depends on what your definition of "a great job" is?

[Stormcenter]

one problem... the model initial heading is wrong. The center is well to the south near 14N and i moving nearly due west. This one is likely to enter the Carib, not pass north of it

ah but its a weak "center" and a new one could be under the deeper convection that is shearing off to the NE, that is the problem. If the center develops north of 15N then its not likely it is a Caribbean storm based on 150 years of climatology in this area. GFS 500mb flow shows a small weakness NW of 92L due to the UL trough which could allow a NW movement and then the weakness quickly fills in within 12-24 hours with dominant East to West flow which would bend it back nearly due west.

Members can see the "weakness" and UL trough I mention in this WV image. Note the circular area NNW of 92L (aka the ULL or TUTT) and imagine a trough axis extending SW from that. Wind flow is SW E of the axis and nearly due E W of the axis. Once 92L crosses the axis the UL environment becomes very favorable for development.

All Indications are that the center is above 15 north and moving Wnw as far as I see.

That is what it "looks" like to me but I'm no expert.

[ronjon]

HPC this morning:

PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
918 AM EDT TUE AUG 12 2008

VALID 12Z SAT AUG 16 2008 - 12Z TUE AUG 19 2008

PRELIMINARY UPDATE...

WITH THE ADVENT OF THE FULL 00Z NUMERICAL MODEL SUITE...UPDATED TO A BLEND OF THE 00Z ECMWF AND 00Z EUROPEAN CENTRE ENSEMBLE MEAN FOR THE PRELIMINARY FRONTS AND PRESSURES FOR DAYS 3 THROUGH 7. THE 00Z GFS...AND TO A LESSER EXTENT THE 06Z RUN...TUCK THE UPPER LOW FARTHER WEST OVER THE PLAINS THAN THE GEFS MEAN...ECMWF...AND EC MEAN DURING THE SECOND HALF OF THE PERIOD. SPAGHETTI PLOT SHOWS
NO SIGNIFICANT CLUSTERING AROUND THE 00Z DETERMINISTIC GFS...SO DID NOT GIVE IT ANY WEIGHT IN THE FORECAST.

EXTRAPOLATED YESTERDAYS TPC COORDINATED TRACK OF THE POSSIBLE TROPICAL SYSTEM INTO THE EASTERN GULF OF MEXICO FOR DAY 7. WILL TAKE ANOTHER LOOK AT IT DURING TODAYS CONFERENCE CALL.

[gatorcane]

NWS Miami has not mentioned 92L yet in the AFD but I am expecting a blurb on it sometime today or tomorrow if trends continue

[N2Storms]

[quote="caneman"]When the Euro and GFDL speak, I listen.[/quote]


From the Tallahassee NWS AFD


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000
FXUS62 KTAE 120806
AFDTAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
406 AM EDT TUE AUG 12 2008

.ALSO THE 00Z EURO IS MORE BULLISH ON
TRACKING A POSSIBLE TROPICAL SYSTEM ACROSS CUBA MONDAY AND INTO
THE SOUTHEAST GULF TUESDAY. WITH THE AXIS OF THE SHARP UPPER
TROUGH TO OUR WEST...THIS WILL HAVE TO WATCHED CLOSELY.

&&

[Blown Away]

NWS Miami has not mentioned 92L yet in the AFD but I am expecting a blurb on it sometime today or tomorrow if trends continue

NATIONAL WEATHER SERVICE MELBOURNE FL
304 AM EDT TUE AUG 12 2008

.DISCUSSION...

THU-SAT...RAIN CHANCES REMAIN ABOVE CLIMO AS RIDGE AXIS REMAINS TOTHE SOUTH AND HIGH PWS COMBINED WITH MOSTLY WESTERLY SURFACE WINDS.

SUN-MON...BY SUNDAY A MORE EASTERLY FLOW SETS UP AND A SERIES OF WEAK EASTERLY WAVES PUSH THROUGH THE AREA SUNDAY AND MONDAY.

[MWatkins]

one problem... the model initial heading is wrong. The center is well to the south near 14N and i moving nearly due west. This one is likely to enter the Carib, not pass north of it

Are you basing that center fix purely on the QScat pass from 9Z? If so, looked like a sw to ne elongated wave axis that stretches from 14 to 15.2 or so. Thunderstorm activity has consolidated near the NE edge of that axis since then...which is probably why the init position is up near 15.5. Still might be moving into the Caribbean, but the center is not down near 14 IMHO.

MW