CPAC: NORMAN - Post-Tropical

[Brent]

Euro went towards the GFS and goes way north of Hawaii

[Kingarabian]

Big shifts north on this 00z suite. Time frame also pushed back. Nearly 11 days out.

There's also a lot of spread than normal just 72 hours out. Looks like a tricky forecast. GFS keeps the ridge off Baja/WCONUS weak and shows more poleward movement, and also keeps the ridge in the CPAC weak as well. Euro has a stronger Baja/WCONUS ridge but shows a weaker CPAC ridge like it previously had 2 days ago.

Hard to find a good analog for this system. Can't seem to find a storm that formed this far north, and forecast to dip this south. Lester, Julio 2014, Guillermo 2009 didn't have this dip.

[Twisted-core]

Its good to see ec shift in the track, being on this one run so far it's not
a trend. And its a little to early to craft any forecasts. Lets hope it does become
a trend and Norman reaches full maturity and curves safely away.

[cycloneye]

Tropical Storm Norman Discussion Number 4
NWS National Hurricane Center Miami FL EP162018
300 AM MDT Wed Aug 29 2018

Even though there has been a dearth of microwave imagery overnight,
Norman's infrared satellite signature has the look of a cyclone
ready to strengthen significantly over the next couple of days.
Banding continues to increase, with the convective canopy expanding
in nearly all quadrants. Norman's initial intensity is set at 50
kt based on a blend of Dvorak estimates from TAFB and SAB. Ocean
waters of nearly 30 degrees Celsius and low shear for the next
couple of days are offering an ideal environment for Norman to
rapidly intensify. The various Rapid Intensification (RI) indices
continue to show high probabilities, and overall the new intensity
guidance is higher than the previous forecast during the first
36 hours. Based on these numbers, the updated NHC intensity
forecast has been bumped upward, close to the Florida State
Superensemble and intensity consensus aids, but still not nearly as
high as the HWRF or HCCA models. It wouldn't be surprising at all
for the forecast intensities to be increased further in subsequent
advisory packages, and Norman is likely to become a hurricane later
today.

Norman is moving westward, or 275/9 kt, to the south of the
subtropical ridge, which extends westward from northern Mexico.
The ridge is forecast to build westward during the next few days,
causing Norman to continue westward--or even west-southwestward--at
a fairly steady pace for the next 4-5 days. Except for the GFS,
which appears to be a bit of a northern outlier, the remainder of
the track guidance is tightly clustered, at least for the first 3
days. After that time, the overall guidance envelope has shifted
slightly northward, requiring a subtle northward adjustment of the
NHC official forecast by day 5. This new forecast generally lies
closest to the HCCA and Florida State Superensemble aids.

FORECAST POSITIONS AND MAX WINDS

INIT 29/0900Z 17.5N 114.6W 50 KT 60 MPH
12H 29/1800Z 17.8N 115.8W 65 KT 75 MPH
24H 30/0600Z 18.0N 117.3W 85 KT 100 MPH
36H 30/1800Z 18.1N 118.9W 100 KT 115 MPH
48H 31/0600Z 17.8N 120.5W 110 KT 125 MPH
72H 01/0600Z 16.7N 124.1W 110 KT 125 MPH
96H 02/0600Z 16.0N 128.0W 100 KT 115 MPH
120H 03/0600Z 17.0N 132.5W 90 KT 105 MPH

$$
Forecaster Berg

[wx98]

154
WTPZ41 KNHC 291434
TCDEP1

Tropical Storm Norman Discussion Number 5
NWS National Hurricane Center Miami FL EP162018
800 AM PDT Wed Aug 29 2018

The cloud pattern has continued to improved in organization, and
SSMIS data at 1400 UTC indicate that an inner core is beginning to
form. The area of convection is large with a well defined
cyclonically curved band wrapping around the system, while the
upper-level outflow is expanding westward. Based on objective and
subjective T-numbers, the initial intensity has been set at 55 kt.
The environment of low shear and warm waters is ideal for Norman to
intensify, and in fact, the Rapid Intensification (RI) indices are
quite high. On this basis, the NHC forecast calls for Norman to
become a hurricane by tonight and a major hurricane in a day or so.

The best estimate of the initial motion is toward the
west-northwest or 285 degrees at 9 kt. The hurricane is ready to
start moving more westward or even on a west-southwestward track as
the nose of the ridge to the north begins to expand westward and
amplify. Most of the models captured the building of the ridge, and
unanimously forecast the cyclone to move west-southwestward for the
next 2 to 4 days. The confidence is the forecast during the first 3
to 4 days is high since track models are really clustered. The new
NHC forecast is not too different from the previous one, and it lies
between the corrected consensus HCCA and the multimodel aids.


FORECAST POSITIONS AND MAX WINDS

INIT 29/1500Z 17.8N 115.7W 55 KT 65 MPH
12H 30/0000Z 17.9N 116.6W 65 KT 75 MPH
24H 30/1200Z 18.1N 118.2W 90 KT 105 MPH
36H 31/0000Z 17.9N 119.8W 105 KT 120 MPH
48H 31/1200Z 17.5N 121.4W 110 KT 125 MPH
72H 01/1200Z 16.2N 124.8W 110 KT 125 MPH
96H 02/1200Z 16.0N 129.0W 100 KT 115 MPH
120H 03/1200Z 17.5N 134.0W 90 KT 105 MPH

$$
Forecaster Avila

[Kingarabian]

[Yellow Evan]

29/1800 UTC 17.5N 115.4W T4.0/4.0 NORMAN -- East Pacific

[Kingarabian]

12z Euro has Norman similar to Miriam, recurving well east of Hawaii.

[Yellow Evan]

* EAST PACIFIC 2018 SHIPS INTENSITY FORECAST *
* IR SAT DATA AVAILABLE, OHC AVAILABLE *
* NORMAN EP162018 08/29/18 18 UTC *

TIME (HR) 0 6 12 18 24 36 48 60 72 84 96 108 120
V (KT) NO LAND 65 72 77 82 87 90 91 87 83 84 80 75 68
V (KT) LAND 65 72 77 82 87 90 91 87 83 84 80 75 68
V (KT) LGEM 65 72 78 83 86 89 90 89 88 86 82 76 70
Storm Type TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP

SHEAR (KT) 9 8 9 11 13 13 14 21 19 18 12 12 13
SHEAR ADJ (KT) -4 -2 -3 -2 -2 -3 0 0 4 0 5 8 7
SHEAR DIR 66 105 99 75 67 72 45 65 57 79 103 104 121
SST (C) 29.6 29.5 29.4 29.3 29.1 28.8 28.6 28.5 28.3 28.0 27.9 27.5 27.4
POT. INT. (KT) 160 159 158 157 155 152 150 149 147 145 144 140 139
200 MB T (C) -52.9 -52.1 -52.4 -52.9 -52.6 -52.5 -51.9 -51.8 -51.8 -51.8 -52.0 -51.7 -52.1
200 MB VXT (C) 0.0 0.0 0.1 0.4 0.5 0.8 0.9 1.1 1.1 0.7 0.6 0.8 0.7
TH_E DEV (C) 6 6 6 6 5 5 5 6 6 6 6 6 6
700-500 MB RH 68 68 65 67 66 62 63 61 63 60 61 58 56
MODEL VTX (KT) 20 21 22 23 24 24 26 26 27 30 30 29 27
850 MB ENV VOR 21 23 23 33 43 50 66 81 88 97 92 104 112
200 MB DIV 71 81 58 34 36 3 32 20 20 12 -9 -12 2
700-850 TADV -6 -5 -3 0 -1 0 0 -1 0 -6 -4 -5 -5
LAND (KM) 837 887 925 974 1027 1167 1329 1510 1709 1878 2020 2170 2083
LAT (DEG N) 17.6 17.8 17.9 17.9 17.9 17.6 17.1 16.5 15.8 15.7 16.2 17.0 17.8
LONG(DEG W) 115.7 116.5 117.3 118.1 118.9 120.5 122.1 123.8 125.6 127.7 130.1 132.6 135.1
STM SPEED (KT) 7 8 8 8 8 8 9 9 10 11 12 13 13
HEAT CONTENT 13 12 12 13 14 26 13 14 23 20 14 5 7

FORECAST TRACK FROM OFCI INITIAL HEADING/SPEED (DEG/KT):275/ 7 CX,CY: -6/ 1
T-12 MAX WIND: 50 PRESSURE OF STEERING LEVEL (MB): 527 (MEAN=584)
GOES IR BRIGHTNESS TEMP. STD DEV. 50-200 KM RAD: 7.4 (MEAN=14.5)
% GOES IR PIXELS WITH T < -20 C 50-200 KM RAD: 100.0 (MEAN=65.0)
PRELIM RI PROB (DV .GE. 55 KT IN 48 HR): 19.8

INDIVIDUAL CONTRIBUTIONS TO INTENSITY CHANGE
6 12 18 24 36 48 60 72 84 96 108 120
----------------------------------------------------------
SAMPLE MEAN CHANGE 0. 0. 1. 1. 1. 1. 1. 0. -1. -1. -2. -3.
SST POTENTIAL 1. 2. 3. 4. 5. 5. 4. 3. 3. 2. 1. 0.
VERTICAL SHEAR MAG 0. 0. 0. 0. -1. -1. -2. -4. -4. -4. -4. -4.
VERTICAL SHEAR ADJ 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.
VERTICAL SHEAR DIR 0. 0. 1. 1. 2. 3. 4. 5. 6. 6. 6. 5.
PERSISTENCE 4. 5. 6. 6. 5. 3. 2. 1. 1. 1. 0. 0.
200/250 MB TEMP. 0. 0. 0. 0. -1. -1. 0. 0. 1. 1. 1. 1.
THETA_E EXCESS 0. 0. 0. 0. 0. -1. -1. -1. -1. -1. -1. -1.
700-500 MB RH 0. 0. 0. 0. 0. 0. 0. 1. 0. 0. 0. 0.
MODEL VTX TENDENCY 0. 1. 2. 4. 4. 6. 7. 9. 14. 14. 12. 9.
850 MB ENV VORTICITY 0. 0. 0. 0. 0. 0. -1. -1. -1. -2. -2. -3.
200 MB DIVERGENCE 0. 0. 1. 1. 0. 0. 0. 0. -1. -1. -2. -2.
850-700 T ADVEC 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. -1.
ZONAL STORM MOTION 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.
STEERING LEVEL PRES 0. 0. 0. 0. 0. 0. 0. -1. -1. -1. -1. -1.
DAYS FROM CLIM. PEAK 0. 0. 0. 0. 0. 0. 1. 1. 2. 2. 2. 2.
GOES PREDICTORS 1. 2. 3. 3. 4. 4. 3. 3. 2. 2. 2. 2.
OCEAN HEAT CONTENT 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.
RI POTENTIAL 0. 1. 2. 3. 5. 7. 5. 2. 0. -1. -2. -3.
----------------------------------------------------------
TOTAL CHANGE 7. 12. 17. 22. 25. 26. 22. 18. 19. 15. 10. 3.

CURRENT MAX WIND (KT): 65. LAT, LON: 17.6 115.7

** 2018 E. Pacific RI INDEX EP162018 NORMAN 08/29/18 18 UTC **
(SHIPS-RII PREDICTOR TABLE for 30 KT OR MORE MAXIMUM WIND INCREASE IN NEXT 24-h)

Predictor Value RI Predictor Range Scaled Value(0-1) % Contribution
POT = MPI-VMAX (KT) : 92.7 40.5 to 149.3 0.48 5.7
12 HR PERSISTENCE (KT) : 15.0 -22.0 to 44.0 0.56 7.9
850-200 MB SHEAR (KT) : 10.0 19.6 to 1.4 0.53 5.9
HEAT CONTENT (KJ/CM2) : 12.8 1.8 to 106.7 0.10 0.9
D200 (10**7s-1) : 56.0 -33.0 to 156.2 0.47 4.7
STD DEV OF IR BR TEMP : 7.4 37.8 to 2.1 0.85 6.9
MAXIMUM WIND (KT) : 65.0 22.5 to 132.0 0.89 7.1
BL DRY-AIR FLUX (W/M2) : 303.0 721.6 to -82.5 0.52 -3.6
%area of TPW <45 mm upshear : 0.0 62.3 to 0.0 1.00 0.9
2nd PC OF IR BR TEMP : -0.2 2.2 to -1.9 0.59 0.7

SHIPS Prob RI for 20kt/ 12hr RI threshold= 33% is 5.3 times climatological mean ( 6.1%)
SHIPS Prob RI for 25kt/ 24hr RI threshold= 47% is 3.8 times climatological mean (12.5%)
SHIPS Prob RI for 30kt/ 24hr RI threshold= 37% is 4.4 times climatological mean ( 8.4%)
SHIPS Prob RI for 35kt/ 24hr RI threshold= 31% is 5.2 times climatological mean ( 6.0%)
SHIPS Prob RI for 40kt/ 24hr RI threshold= 18% is 4.6 times climatological mean ( 4.0%)
SHIPS Prob RI for 45kt/ 36hr RI threshold= 22% is 3.3 times climatological mean ( 6.5%)
SHIPS Prob RI for 55kt/ 48hr RI threshold= 18% is 3.1 times climatological mean ( 5.9%)
SHIPS Prob RI for 65kt/ 72hr RI threshold= 0% is 0.0 times climatological mean ( 4.8%)

Matrix of RI probabilities
------------------------------------------------------------------------------
RI (kt / h) | 20/12 | 25/24 | 30/24 | 35/24 | 40/24 | 45/36 | 55/48 |65/72
------------------------------------------------------------------------------
SHIPS-RII: 32.6% 47.1% 37.2% 31.2% 18.4% 21.8% 18.3% 0.0%
Logistic: 37.6% 41.8% 32.2% 26.1% 26.5% 19.1% 9.4% 1.0%
Bayesian: 10.0% 12.0% 3.7% 2.3% 1.7% 1.0% 0.1% 0.0%
Consensus: 26.8% 33.6% 24.4% 19.9% 15.5% 13.9% 9.3% 0.3%
DTOPS: 87.0% 93.0% 85.0% 67.0% 67.0% 80.0% 32.0% 4.0%

## ANNULAR HURRICANE INDEX (AHI) EP162018 NORMAN 08/29/18 18 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) ##

CONTRIBUTIONS TO ANNULAR INDEX

[Kingarabian]

Whatever happened to SHIPS? All of a sudden it's become one of the more conservative intensity models.

[mrbagyo]

Hurricane Norman

16E NORMAN 180829 1800 17.6N 115.7W EPAC 65 987

[Kingarabian]

12z EPS 10 days out, can't write off a threat yet.

[cycloneye]

Hurricane Norman Discussion Number 6
NWS National Hurricane Center Miami FL EP162018
200 PM PDT Wed Aug 29 2018

Norman's cloud pattern has continued to organize with numerous
convective bands and excellent upper-level outflow. More
importantly, satellite images show an eye feature which has been
depicted intermittently. Dvorak numbers from TAFB and SAB have
reached T4.0, and on this basis, Norman is being upgraded to
hurricane status in this advisory. The environment of low shear and
warm ocean continues to be ideal for intensification, and guidance
continues to be pretty aggressive in bringing the winds up fast.
The NHC forecast indicates rapid intensification, and predicts
Norman to become a major hurricane in about 24 hours.

Norman appears to be moving toward the west or 270 degrees at 8 kt.
The high pressure ridge which is controlling the motion of the
hurricane is expanding westward, and the flow pattern around the
ridge should steer Norman on a west or even west-southwest track
for the next 3 to 4 days. Track guidance continues to be in
remarkably good agreement, and models are tightly clustered at
least for the next 3 to 4 days. The NHC forecast is very similar to
the previous one, and continue to lie very close to the corrected
consensus HCCA and the multi-model aids. The confidence in the track
forecast is quite high at this time.


FORECAST POSITIONS AND MAX WINDS

INIT 29/2100Z 17.6N 116.1W 65 KT 75 MPH
12H 30/0600Z 17.8N 117.3W 80 KT 90 MPH
24H 30/1800Z 17.9N 118.8W 100 KT 115 MPH
36H 31/0600Z 17.5N 120.5W 110 KT 125 MPH
48H 31/1800Z 17.0N 122.0W 115 KT 130 MPH
72H 01/1800Z 16.0N 125.5W 110 KT 125 MPH
96H 02/1800Z 16.0N 130.0W 100 KT 115 MPH
120H 03/1800Z 17.5N 135.0W 90 KT 105 MPH

$$
Forecaster Avila

[cycloneye]

30/0000 UTC 17.8N 116.1W T4.5/4.5 NORMAN -- East Pacific

[cycloneye]

[cycloneye]

Hurricane Norman Discussion Number 7
NWS National Hurricane Center Miami FL EP162018
800 PM PDT Wed Aug 29 2018

Norman is steadily strengthening. Recent microwave images indicate
that the hurricane now has a well-defined inner core with a banded
eye feature evident in that data. The eye is not yet apparent in
geostationary images, but the convective pattern is improving in
organization and the cloud tops continue to become colder. A blend
of the satellite intensity estimates at 0000 UTC supported an
initial intensity of 70 kt, and since the system continues to
become better organized, the initial wind speed for this advisory is
increased to 75 kt. Now that Norman has an inner core, rapid
intensification is expected during the next 24 hours or so while the
hurricane remains in near ideal environmental conditions. The SHIPS
rapid intensification indices are very high, and the NHC intensity
forecast remains near the upper end of the model guidance in the
short term. Beyond a couple of days, an increase in shear
and slightly cooler waters should promote a gradual weakening trend.

Satellite images suggest that the forward speed of Norman has
slowed to 280/7 kt. All of the models show a mid-level ridge
amplifying to the north of the tropical cyclone during the next few
days, and this should cause the hurricane to move westward or
west-southwestward during that time. Thereafter, a turn back to the
west and then west-northwest with an increase in forward speed is
predicted as Norman moves closer to the western periphery of the
ridge. The model guidance remains in fairly good agreement, and
the NHC track forecast lies near the various consensus aids.

FORECAST POSITIONS AND MAX WINDS

INIT 30/0300Z 17.9N 116.5W 75 KT 85 MPH
12H 30/1200Z 18.0N 117.6W 95 KT 110 MPH
24H 31/0000Z 18.0N 119.2W 105 KT 120 MPH
36H 31/1200Z 17.5N 120.8W 115 KT 130 MPH
48H 01/0000Z 16.8N 122.5W 110 KT 125 MPH
72H 02/0000Z 16.0N 126.3W 105 KT 120 MPH
96H 03/0000Z 16.9N 130.9W 95 KT 110 MPH
120H 04/0000Z 18.5N 136.0W 80 KT 90 MPH

$$
Forecaster Cangialosi

[Twisted-core]

154
WTPZ41 KNHC 291434
TCDEP1

Tropical Storm Norman Discussion Number 5
NWS National Hurricane Center Miami FL EP162018
800 AM PDT Wed Aug 29 2018

The cloud pattern has continued to improved in organization, and
SSMIS data at 1400 UTC indicate that an inner core is beginning to
form. The area of convection is large with a well defined
cyclonically curved band wrapping around the system, while the
upper-level outflow is expanding westward. Based on objective and
subjective T-numbers, the initial intensity has been set at 55 kt.
The environment of low shear and warm waters is ideal for Norman to
intensify, and in fact, the Rapid Intensification (RI) indices are
quite high. On this basis, the NHC forecast calls for Norman to
become a hurricane by tonight and a major hurricane in a day or so.

The best estimate of the initial motion is toward the
west-northwest or 285 degrees at 9 kt. The hurricane is ready to
start moving more westward or even on a west-southwestward track as
the nose of the ridge to the north begins to expand westward and
amplify. Most of the models captured the building of the ridge, and
unanimously forecast the cyclone to move west-southwestward for the
next 2 to 4 days. The confidence is the forecast during the first 3
to 4 days is high since track models are really clustered. The new
NHC forecast is not too different from the previous one, and it lies
between the corrected consensus HCCA and the multimodel aids.


FORECAST POSITIONS AND MAX WINDS

INIT 29/1500Z 17.8N 115.7W 55 KT 65 MPH
12H 30/0000Z 17.9N 116.6W 65 KT 75 MPH
24H 30/1200Z 18.1N 118.2W 90 KT 105 MPH
36H 31/0000Z 17.9N 119.8W 105 KT 120 MPH
48H 31/1200Z 17.5N 121.4W 110 KT 125 MPH
72H 01/1200Z 16.2N 124.8W 110 KT 125 MPH
96H 02/1200Z 16.0N 129.0W 100 KT 115 MPH
120H 03/1200Z 17.5N 134.0W 90 KT 105 MPH

$$
Forecaster Avila

[Yellow Evan]

----- Current Analysis -----
Date : 30 AUG 2018 Time : 053000 UTC
Lat : 17:49:11 N Lon : 116:51:36 W


CI# /Pressure/ Vmax
4.5 / 976.4mb/ 77.0kt


Final T# Adj T# Raw T#
4.5 4.5 6.3

Estimated radius of max. wind based on IR : 6 km

Center Temp : -35.4C Cloud Region Temp : -72.0C

Scene Type : EYE

[cycloneye]

Going thru RI.

EP, 16, 2018083006, , BEST, 0, 178N, 1170W, 95, 968, H

[Yellow Evan]