EPAC: OLAF - Post-Tropical

[WeatherGuesser]

12z ECMWF seems to have backed off somewhat. This better not be another Nora.

I still don't understand why people get so hung up on models. Sit back. Relax. Let Mother Nature do her thing. Don't try to figure her out.

[Yellow Evan]

12z ECMWF seems to have backed off somewhat. This better not be another Nora.

I still don't understand why people get so hung up on models. Sit back. Relax. Let Mother Nature do her thing. Don't try to figure her out.

Without trying to understand mother nature, how are we going to?

[cycloneye]

TROPICAL DEPRESSION NINETEEN-E DISCUSSION NUMBER 4
NWS NATIONAL HURRICANE CENTER MIAMI FL EP192015
200 PM PDT THU OCT 15 2015

Visible satellite images suggest that the depression is not very
well organized. The circulation is still somewhat elongated, and
the low-level center is located near the eastern edge of a cluster
of deep convection. The convection itself also appears to have
lost some organization since earlier today. The maximum winds
remain 30 kt based on Dvorak CI numbers of 2.0 from TAFB and SAB.
Even though environmental conditions appear conducive for
strengthening, the depression is not in any hurry to intensify.
The hurricane intensity models and the global models all insist
that the depression will strengthen soon. However, the one
prominent difference in this afternoon's model suite is that the
ECMWF model does not deepen the cyclone for another 48 hours or
so. Since most of the guidance intensifies the system through 5
days, the NHC intensity forecast remains consistent with the
previous forecasts, making the cyclone a hurricane in about 2-3
days. This is also consistent with the latest intensity consensus.
However, given the latest ECMWF run and the current structure of the
depression, it's possible that intensification could be delayed.

The initial motion is 265/11 kt. A mid-level ridge is steering the
depression westward, and this motion is likely to continue for at
least another 48 hours. After that time, the ridge is forecast to
weaken and give way to a broad trough west of the Baja California
peninsula. This should allow the cyclone to turn west-northwestward
and then northwestward by day 5. Although the track models
generally agree on this scenario, the system's weaker representation
in the ECMWF during the first few days causes it to continue
westward beyond 48 hours and make a more gradual turn compared to
the other models. This now places the ECMWF closer to the UKMET
model, which was the only outlier on the previous forecast cycle.
Based on the new guidance, the NHC track forecast has been shifted
westward and is a little bit slower than the previous forecast,
especially at days 4 and 5.

FORECAST POSITIONS AND MAX WINDS

INIT 15/2100Z 10.1N 120.9W 30 KT 35 MPH
12H 16/0600Z 9.9N 122.8W 35 KT 40 MPH
24H 16/1800Z 9.9N 125.1W 45 KT 50 MPH
36H 17/0600Z 9.8N 127.0W 55 KT 65 MPH
48H 17/1800Z 9.9N 128.6W 65 KT 75 MPH
72H 18/1800Z 10.7N 131.3W 80 KT 90 MPH
96H 19/1800Z 12.5N 134.0W 85 KT 100 MPH
120H 20/1800Z 15.0N 137.0W 90 KT 105 MPH

$$
Forecaster Berg

[Kingarabian]

I'm going to be shocked if the Navgem and CMC turn out to be right.

[Kingarabian]

1.5/1.5 from SAB. This phantom mid level shear seems to be at work again.

We could still some decent ACE numbers as the Euro, Navy, and CMC show it strengthening later.

[cycloneye]

TROPICAL DEPRESSION NINETEEN-E DISCUSSION NUMBER 5
NWS NATIONAL HURRICANE CENTER MIAMI FL EP192015
800 PM PDT THU OCT 15 2015

The cloud pattern of the depression has appeared ragged in satellite
images most of the day, and the latest Dvorak CI-numbers from TAFB
and SAB have decreased to 1.5/25 kt. The associated deep convection
does not have much curvature and it is largely confined to areas to
the north and west of the estimated center. Based on the degraded
appearance, the initial wind speed is lowered slightly to 25 kt.

It is not clear why the depression has not strengthened today as the
large-scale environmental conditions have been quite conducive for
intensification. The depression is expected to remain in a low wind
shear and high moisture environment and over warm water for at least
the next few days. Therefore, it is assumed that the system will
have the opportunity to gain strength. The GFS, as well as the
GFS-based SHIPS and LGEM guidance, are the most aggressive models
and show the cyclone becoming a hurricane in a couple of days with
continued strengthening thereafter. Conversely, the GFDL and HWRF
models show much less strengthening. Given the poor initial
structure of the cyclone, the official intensity forecast has been
lowered in the short term but remains relatively unchanged from the
previous prediction at the later forecast times.

The depression is moving westward at about 11 kt steered by a
subtropical ridge to its north. A continued westward motion but at
a slower pace is forecast during the next couple of days while the
ridge weakens in place. After that time, a turn to the northwest
is expected as a weakness develops in the ridge east of the
Hawaiian Islands. Although there is considerable spread in the
guidance on when the northwestward turn should occur, the models
agree on the overall theme. The new official track forecast is
essentially an update of the previous one for the first couple of
days, but then is shifted westward to come into better agreement
with the latest model consensus aids.

FORECAST POSITIONS AND MAX WINDS

INIT 16/0300Z 10.2N 122.1W 25 KT 30 MPH
12H 16/1200Z 10.1N 124.0W 30 KT 35 MPH
24H 17/0000Z 10.0N 126.2W 35 KT 40 MPH
36H 17/1200Z 9.9N 128.0W 45 KT 50 MPH
48H 18/0000Z 10.2N 129.6W 55 KT 65 MPH
72H 19/0000Z 11.1N 132.3W 75 KT 85 MPH
96H 20/0000Z 12.7N 135.1W 85 KT 100 MPH
120H 21/0000Z 15.1N 137.8W 85 KT 100 MPH

$$
Forecaster Cangialosi

[Yellow Evan]

Despite the system's recent struggles, wind shear appears to be backing away at the mid-levels and the GFS shows an extremely favorable upper-level pattern for the next 5 days. ECMWF is less bullish, but still shows good outflow aloft. If these setups verify, this will still likely become a Category 3 or 4 hurricane.

[Kingarabian]

Convection looks flat to the N of the system. Maybe northerly shear affecting it.

[Kingarabian]

Decent banding. I would upgrade.

[WeatherGuesser]

Personally, I hope this is another Bust just to deal with the model huggers.

[Yellow Evan]

Convection looks flat to the N of the system. Maybe northerly shear affecting it.

That would mean southerly shear.

I think increased outflow caused the depression to produce more convection, causing it to become elongated and it's re-consolidating right now.

[Yellow Evan]

000
WTPZ44 KNHC 160835
TCDEP4

TROPICAL DEPRESSION NINETEEN-E DISCUSSION NUMBER 6
NWS NATIONAL HURRICANE CENTER MIAMI FL EP192015
200 AM PDT FRI OCT 16 2015

The cloud pattern remains poorly organized and consists of a small
area of deep convection with little or no banding features.
Microwave data suggest that the low-level center is still on the
eastern edge of the convective region. Given that the Dvorak
CI-numbers have not changed significantly, the initial intensity is
kept at 25 kt.

It is surprising that the depression has not responded to the
quite favorable environment of low shear and warm waters yet. In
fact, most the guidance indicated that the depression should have
been already a strong tropical storm or even a hurricane. Since
the opportunity for strengthening is still there, the NHC forecast
insists on intensification and calls for the depression to become a
hurricane in about 3 days.

The depression is trapped south of strong subtropical ridge moving
toward the west at 12 kt. Global models indicate that the ridge will
gradually move eastward. This steering pattern should allow the
cyclone to turn more to the west-northwest in about 3 days, and
eventually to move northward by the end of the forecast period. The
NHC forecast is basically on top of the multi-model consensus and
the GFS/ECMWF solutions. The spread in the guidance has decreased a
little bit, and in general, most of the models now turn the cyclone
northward around 140 W. This increases slightly the confidence in
the long range track forecast.


FORECAST POSITIONS AND MAX WINDS

INIT 16/0900Z 10.1N 123.5W 25 KT 30 MPH
12H 16/1800Z 10.0N 125.4W 35 KT 40 MPH
24H 17/0600Z 10.0N 127.5W 40 KT 45 MPH
36H 17/1800Z 10.0N 129.0W 45 KT 50 MPH
48H 18/0600Z 10.3N 130.5W 55 KT 65 MPH
72H 19/0600Z 11.5N 133.5W 75 KT 85 MPH
96H 20/0600Z 13.0N 136.5W 85 KT 100 MPH
120H 21/0600Z 15.0N 139.0W 85 KT 100 MPH

$$
Forecaster Avila

[Yellow Evan]

TXPZ29 KNES 161223
TCSENP

A. 19E (NONAME)

B. 16/1200Z

C. 9.5N

D. 124.5W

E. THREE/GOES-W

F. T1.5/2.0/S0.0/24HRS

G. IR/EIR/SWIR

H. REMARKS...DT OF 1.5 BASED ON .3 BANDING. MET IS 1.5 BASED ON NO
CHANGE COMPARED TO 24 HOURS AGO. PT IS 1.5. FT IS BASED ON DT.

I. ADDL POSITIONS

NIL


...LIDDICK

[cycloneye]

TROPICAL DEPRESSION NINETEEN-E DISCUSSION NUMBER 7
NWS NATIONAL HURRICANE CENTER MIAMI FL EP192015
800 AM PDT FRI OCT 16 2015

The depression's cloud pattern consists of a recently formed cluster
of deep convection and fragmented convective banding features around
the outer circulation. An 0910 UTC AMSR-2 overpass suggested that
the center was underneath this newly formed convective burst, which
would place it a little south of previous position estimates and
open the possibility that the center recently reformed. An
expansive upper-level outflow is also noted in association with the
cyclone. Dvorak intensity estimates are unchanged from 6 hours ago,
so the initial intensity estimate remains 25 kt.

It is unclear why the cyclone has not yet responded by intensifying
in a large-scale environment of light shear, a relatively moist
mid-troposphere, and very warm waters. Perhaps the structure of the
circulation has been a limiting factor. Regardless, global models
continue to develop a hurricane in the far western portion of the
eastern Pacific basin within a few days. The statistical and
dynamical intensity guidance is quite similar this cycle, though the
statistical output is slightly lower than before as a result of the
cyclone's not intensifying yet. The official intensity forecast
continues to indicate strengthening at a rate very similar to the
multi-model consensus.

The initial motion estimate is a little faster and just south of due
west or 265/14. The cyclone is forecast to maintain a generally
westward motion underneath a subtropical ridge to the north during
the next few days and decelerate as the tail of a mid- to upper-
level trough extending from the U.S. west coast causes the ridge to
weaken. A further weakening of the ridge after 48 hours should
cause the cyclone to begin to gain more latitude, and an encounter
with a more significant weakness west of 140W should result in an
even more poleward track by 96 hours. The track guidance has
shifted significantly to the left this cycle and is a bit faster,
and the official track forecast follows that trend but is on the
right-side of the guidance envelope.


FORECAST POSITIONS AND MAX WINDS

INIT 16/1500Z 9.7N 125.2W 25 KT 30 MPH
12H 17/0000Z 9.6N 127.0W 30 KT 35 MPH
24H 17/1200Z 9.6N 129.0W 40 KT 45 MPH
36H 18/0000Z 9.6N 130.6W 45 KT 50 MPH
48H 18/1200Z 9.9N 132.0W 55 KT 65 MPH
72H 19/1200Z 10.9N 135.0W 75 KT 85 MPH
96H 20/1200Z 12.8N 137.9W 85 KT 100 MPH
120H 21/1200Z 14.9N 140.5W 85 KT 100 MPH

$$
Forecaster Kimberlain

[WeatherGuesser]

"200 AM PDT FRI OCT 16 2015

It is surprising that the depression has not responded to the
quite favorable environment of low shear and warm waters yet. In
fact, most the guidance indicated that the depression should have
been already a strong tropical storm or even a hurricane. "


"800 AM PDT FRI OCT 16 2015

It is unclear why the cyclone has not yet responded by intensifying
in a large-scale environment of light shear, a relatively moist
mid-troposphere, and very warm waters. Perhaps the structure of the
circulation has been a limiting factor. "




Is it wrong to chuckle at this kind of stuff?

[Yellow Evan]

"200 AM PDT FRI OCT 16 2015

It is surprising that the depression has not responded to the
quite favorable environment of low shear and warm waters yet. In
fact, most the guidance indicated that the depression should have
been already a strong tropical storm or even a hurricane. "


"800 AM PDT FRI OCT 16 2015

It is unclear why the cyclone has not yet responded by intensifying
in a large-scale environment of light shear, a relatively moist
mid-troposphere, and very warm waters. Perhaps the structure of the
circulation has been a limiting factor. "




Is it wrong to chuckle at this kind of stuff?

Not really, but you have to give models credit when they are due as well.

[Yellow Evan]

Code: Select all

                    * EAST PACIFIC SHIPS INTENSITY FORECAST          *
                    * IR SAT DATA AVAILABLE,       OHC AVAILABLE     *
                    *  NINETEEN    EP192015  10/16/15  18 UTC        *

TIME (HR)          0     6    12    18    24    36    48    60    72    84    96   108   120
V (KT) NO LAND    30    34    39    43    48    58    69    81    84    87    90    93    91
V (KT) LAND       30    34    39    43    48    58    69    81    84    87    90    93    91
V (KT) LGE mod    30    33    37    42    47    58    70    81    90   100   107   109   107
Storm Type      TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP

SHEAR (KT)         3     3     6     8     9    12    13     6     7     3     5     5     5
SHEAR ADJ (KT)     0     0     2     3     2    -1     0     2    -3    -3    -4    -2    -2
SHEAR DIR         54    20     2   340   321   322   335   349   342   330   210   229   205
SST (C)         29.3  29.4  29.6  29.8  29.9  30.0  30.0  29.8  29.6  29.4  29.2  29.2  29.0
POT. INT. (KT)   159   159   161   163   163   164   164   162   160   159   156   156   153
200 MB T (C)   -52.0 -51.7 -52.0 -52.1 -52.0 -51.9 -52.2 -51.9 -52.0 -52.1 -52.2 -52.2 -51.9
TH_E DEV (C)       9     8     8     8     8     8     8     8     7     7     7     7     6
700-500 MB RH     64    66    67    69    69    73    72    74    75    70    65    61    58
MODEL VTX (KT)    13    13    13    14    15    18    21    25    26    29    31    35    35
850 MB ENV VOR     7    11    15    19    23    20    16    31    46    43    49    71    82
200 MB DIV        53    66    85    67    62    65   115   136   144    88    87   117   119
700-850 TADV      -3    -3    -5    -3    -2    -2    -6    -8    -5     1     8    11     7
LAND (KM)       2201  2278  2357  2425  2495  2598  2613  2441  2264  2068  1880  1698  1566
LAT (DEG N)      9.6   9.6   9.6   9.6   9.6   9.7  10.1  10.6  11.2  12.2  13.5  14.5  15.3
LONG(DEG W)    125.6 126.7 127.8 128.7 129.6 131.0 132.5 134.0 135.5 137.0 138.3 139.7 140.7
STM SPEED (KT)    12    11    10     9     8     7     8     8     8     9     8     7     6
HEAT CONTENT      35    34    26    24    24    24    21    23    27    17    22    32    30

  FORECAST TRACK FROM OFCI      INITIAL HEADING/SPEED (DEG/KT):265/ 13      CX,CY: -12/  0
  T-12 MAX WIND:  25            PRESSURE OF STEERING LEVEL (MB):  541  (MEAN=581)
  GOES IR BRIGHTNESS TEMP. STD DEV.  50-200 KM RAD:  10.4 (MEAN=14.5)
  % GOES IR PIXELS WITH T < -20 C    50-200 KM RAD:  92.0 (MEAN=65.0)

                        INDIVIDUAL CONTRIBUTIONS TO INTENSITY CHANGE
                         6   12   18   24   36   48   60   72   84   96  108  120
                        ----------------------------------------------------------
  SAMPLE MEAN CHANGE     0.   0.   0.   1.   1.   1.   0.   0.  -1.  -1.  -2.  -2.
  SST POTENTIAL          0.   0.   1.   3.   8.  15.  22.  28.  31.  33.  35.  37.
  VERTICAL SHEAR MAG     1.   2.   3.   4.   5.   5.   6.   7.   9.  10.  10.  11.
  VERTICAL SHEAR ADJ     0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   1.   1.
  VERTICAL SHEAR DIR     1.   1.   1.   1.   0.   0.  -1.  -1.  -1.  -3.  -5.  -6.
  PERSISTENCE            1.   1.   2.   2.   2.   2.   2.   1.   1.   1.   1.   0.
  200/250 MB TEMP.       0.  -1.  -2.  -2.  -5.  -7.  -9. -11. -12. -13. -13. -13.
  THETA_E EXCESS         0.   0.   0.   0.   0.   0.  -1.  -1.  -1.  -2.  -2.  -3.
  700-500 MB RH          0.   0.   0.   1.   1.   2.   3.   3.   4.   4.   4.   4.
  MODEL VTX TENDENCY     0.   0.   1.   3.   7.  12.  18.  19.  23.  27.  32.  31.
  850 MB ENV VORTICITY   0.   0.   0.   0.   0.   0.   0.   0.   0.   1.   1.   2.
  200 MB DIVERGENCE      0.   1.   1.   1.   2.   2.   2.   2.   1.   0.  -2.  -4.
  850-700 T ADVEC        0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.
  ZONAL STORM MOTION     0.   1.   1.   2.   2.   3.   4.   4.   3.   3.   3.   3.
  STEERING LEVEL PRES    0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.
  DAYS FROM CLIM. PEAK   0.   0.   0.   0.   0.   0.   0.  -1.  -1.  -1.  -1.  -1.
  GOES PREDICTORS        2.   3.   4.   4.   5.   4.   4.   3.   2.   1.   0.   0.
  OCEAN HEAT CONTENT     0.   0.   1.   1.   1.   1.   1.   1.   1.   1.   1.   1.
                        ----------------------------------------------------------
  TOTAL CHANGE           4.   9.  13.  18.  28.  39.  51.  54.  57.  60.  63.  61.

   ** 2013 E. Pacific RI INDEX EP192015 NINETEEN   10/16/15  18 UTC **
           ( 30 KT OR MORE MAX WIND INCREASE IN NEXT 24 HR)
 
 12 HR PERSISTENCE (KT):   5.0 Range:-22.0 to  38.5 Scaled/Wgted Val:  0.4/  1.0
 850-200 MB SHEAR (KT) :   5.8 Range: 18.7 to   1.4 Scaled/Wgted Val:  0.7/  1.1
 POT = MPI-VMAX (KT)   : 130.9 Range: 40.3 to 141.7 Scaled/Wgted Val:  0.9/  1.0
 STD DEV OF IR BR TEMP :  10.4 Range: 38.9 to   2.4 Scaled/Wgted Val:  0.8/  0.8
 Heat content (KJ/cm2) :  28.6 Range:  3.6 to  75.9 Scaled/Wgted Val:  0.3/  0.3
 D200 (10**7s-1)       :  66.6 Range:-11.0 to 135.3 Scaled/Wgted Val:  0.5/  0.4
 % area w/pixels <-30 C:  86.0 Range: 41.4 to 100.0 Scaled/Wgted Val:  0.8/  0.4
 850-700 MB REL HUM (%):  74.8 Range: 57.6 to  96.8 Scaled/Wgted Val:  0.4/ -0.1
 
 Prob of RI for 25 kt RI threshold=    65% is   5.0 times the sample mean(13.1%)
 Prob of RI for 30 kt RI threshold=    39% is   4.5 times the sample mean( 8.7%)
 Prob of RI for 35 kt RI threshold=    26% is   4.3 times the sample mean( 6.0%)
 Prob of RI for 40 kt RI threshold=    24% is   5.6 times the sample mean( 4.3%)

[Yellow Evan]

----- Current Analysis -----
Date : 16 OCT 2015 Time : 183000 UTC
Lat : 9:35:45 N Lon : 125:41:56 W


CI# /Pressure/ Vmax
3.2 /1003.1mb/ 49.0kt


Final T# Adj T# Raw T#
2.8 2.5 2.4

Center Temp : -45.9C Cloud Region Temp : -49.5C

TXPZ29 KNES 161828
TCSENP

A. 19E (NONAME)

B. 16/1800Z

C. 9.1N

D. 125.6W

E. THREE/GOES-W

F. T2.5/2.5/D1.0/24HRS

G. IR/EIR/VIS

H. REMARKS...DT OF 3.0 BASED ON .6-.7 VISIBLE BANDING. MET IS 2.5 BASED
ON DEVELOPMENT COMPARED TO 24 HOURS AGO. PT IS 2.5. FT IS BASED ON MET.

I. ADDL POSITIONS

NIL


...LIDDICK

[Kingarabian]

Still looks like a depression to me until ASCAT confirms otherwise.

I'm just trying to figure out why it's not a strong TS/hurricane yet.

[cycloneye]

TROPICAL DEPRESSION NINETEEN-E DISCUSSION NUMBER 8
NWS NATIONAL HURRICANE CENTER MIAMI FL EP192015
200 PM PDT FRI OCT 16 2015

The depression's cloud pattern has increased in organization since
yesterday. A small CDO-like feature appears to be forming over the
estimated low-level center. There has also been an increase in
banding features and their associated curvature, especially over the
western half of the circulation. Dvorak intensity estimates have
increased some, and the initial intensity estimate is raised to 30
kt.

Recent fixes suggest that the depression may be slowing down, and
the initial motion estimate could be slightly slower than the
longer-term motion of 265/13. The cyclone is forecast to maintain a
general westward course underneath a mid-level subtropical ridge
during the next 24 to 36 hours but decelerate as the tail of a
mid- to upper- level trough, extending from the U.S. west coast,
causes the ridge to weaken. As the ridge weakens further by 36
hours, the cyclone should begin to gain more latitude. An even
greater in increase in latitude is expected after 96 hours when the
cyclone encounters a more significant weakness west of 140W. The
official track forecast has changed very little compared to the
previous one and is near the multi-model consensus throughout the
forecast period.

With the increased organization of the cyclone's central features,
intensification seems likely in an environment characterized by
very warm SSTs, low shear, and a moist mid-troposphere. In fact,
the SHIPS RI index shows a 65 percent chance of a 25-kt increase in
intensity during the next 24 hours. The official intensity forecast
is raised relative to the previous one, especially during the early
part of the forecast. Given the very conducive large-scale
environment for intensification, it would not be surprising to see
more occur than what is currently forecast.


FORECAST POSITIONS AND MAX WINDS

INIT 16/2100Z 9.5N 126.2W 30 KT 35 MPH
12H 17/0600Z 9.4N 127.7W 40 KT 45 MPH
24H 17/1800Z 9.4N 129.5W 50 KT 60 MPH
36H 18/0600Z 9.5N 131.1W 60 KT 70 MPH
48H 18/1800Z 10.0N 132.6W 70 KT 80 MPH
72H 19/1800Z 11.3N 135.7W 90 KT 105 MPH
96H 20/1800Z 13.4N 138.6W 95 KT 110 MPH
120H 21/1800Z 15.5N 140.6W 90 KT 105 MPH

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Forecaster Kimberlain