EPAC: DOUGLAS - Remnants

[Kingarabian]

00z GFS drops it pretty much.
00z HMON/HWRF weaker but the former continues to make it a hurricane.

00z UKMET/CMC stronger peak.
00z Euro shifts south of Hawaii, but just barely misses the Big Island to the south. Potentially giving Kona and Puna 60kt winds. The Euro and UKMET so far have been the strongest of the bunch in terms of potential Hawaii impacts. Still a loong way out and this will likely change quite a bit.

Actually throw out the 00z GFS. It's initializing it way too weak compared to the rest.

[Kingarabian]

A low pressure system producing an area of thunderstorms more than
800 miles southwest of the southern tip of the Baja California
peninsula continues to show signs of organization. Environmental
conditions are expected to be conducive for development of this
system, and a tropical depression could form during the next couple
of days while it moves west-southwestward and then westward at
about 10 mph.
* Formation chance through 48 hours...medium...50 percent.
* Formation chance through 5 days...high...80 percent.

20/0530 UTC 14.4N 119.1W T1.5/1.5 90E -- East Pacific

[cycloneye]

A low pressure system located about 850 miles southwest of the
southern tip of the Baja California peninsula continues to show
signs of organization, and recent satellite-derived wind data
indicate that the low is producing winds just below tropical storm
force. Environmental conditions are conducive for additional
development, and a tropical depression or tropical storm is likely
to form during the next day or two while the low moves
west-southwestward and then westward at 10 to 15 mph.
* Formation chance through 48 hours...high...70 percent.
* Formation chance through 5 days...high...90 percent.

[Yellow Evan]

20/1130 UTC 13.9N 119.4W T1.5/1.5 90E -- East Pacific

[Yellow Evan]

* GFS version *
* EAST PACIFIC 2020 SHIPS INTENSITY FORECAST *
* IR SAT DATA AVAILABLE, OHC AVAILABLE *
* INVEST EP902020 07/20/20 12 UTC *

TIME (HR) 0 6 12 18 24 36 48 60 72 84 96 108 120 132 144 156 168
V (KT) NO LAND 30 33 36 40 44 51 56 58 61 62 61 62 60 58 56 56 55
V (KT) LAND 30 33 36 40 44 51 56 58 61 62 61 62 60 58 56 56 55
V (KT) LGEM 30 32 35 37 40 46 50 51 50 47 44 41 37 34 31 28 26
Storm Type TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP

SHEAR (KT) 8 9 7 5 4 4 4 3 1 3 5 5 4 8 12 13 17
SHEAR ADJ (KT) -3 -3 -3 -3 -1 0 0 0 2 -2 -1 0 -1 -1 -3 -4 -4
SHEAR DIR 42 44 52 46 6 341 307 246 263 223 253 198 250 236 271 275 287
SST (C) 28.8 28.9 28.8 28.4 28.3 28.2 28.4 28.1 28.2 28.0 26.7 26.5 25.8 25.6 26.0 25.8 26.3
POT. INT. (KT) 152 153 153 149 148 148 150 147 148 146 132 130 123 121 126 124 130
200 MB T (C) -54.0 -54.0 -54.0 -54.0 -54.2 -54.2 -54.3 -54.1 -54.3 -54.3 -54.3 -54.0 -54.2 -54.1 -54.2 -54.3 -54.2
200 MB VXT (C) 0.2 0.2 0.1 0.1 0.0 -0.3 -0.3 -0.4 -0.4 -0.3 -0.1 0.1 0.2 0.1 0.1 0.1 -0.1
TH_E DEV (C) 7 7 7 7 6 6 5 5 5 5 4 4 4 4 5 6 7
700-500 MB RH 68 64 66 67 68 71 74 72 70 65 62 59 56 49 46 44 43
MODEL VTX (KT) 3 4 4 5 6 7 8 8 9 10 10 10 9 8 6 5 2
850 MB ENV VOR 1 9 16 23 29 47 54 43 25 -4 -21 -27 -28 -37 -30 -43 -44
200 MB DIV 67 68 55 42 39 8 9 7 4 6 2 9 -6 -23 -20 -14 -33
700-850 TADV 3 4 3 2 4 2 3 -1 0 2 4 6 4 7 4 6 3
LAND (KM) 1408 1508 1608 1703 1802 2053 2276 2463 2346 2023 1694 1369 1051 715 396 236 488
LAT (DEG N) 13.9 xx.x xx.x xx.x xx.x xx.x xx.x xx.x xx.x xx.x xx.x xx.x xx.x xx.x xx.x xx.x xx.x
LONG(DEG W) 119.4 xxx.x xxx.x xxx.x xxx.x xxx.x xxx.x xxx.x xxx.x xxx.x xxx.x xxx.x xxx.x xxx.x xxx.x xxx.x xxx.x
STM SPEED (KT) 8 9 10 11 12 13 13 14 14 15 15 15 15 16 17 17 18
HEAT CONTENT 27 32 26 16 12 11 12 12 14 14 2 1 0 0 0 0 2

FORECAST TRACK FROM OFPI INITIAL HEADING/SPEED (DEG/KT):215/ 6 CX,CY: -2/ -4
T-12 MAX WIND: 25 PRESSURE OF STEERING LEVEL (MB): 685 (MEAN=587)
GOES IR BRIGHTNESS TEMP. STD DEV. 50-200 KM RAD: 21.2 (MEAN=14.5)
% GOES IR PIXELS WITH T < -20 C 50-200 KM RAD: 51.0 (MEAN=65.0)
PRELIM RI PROB (DV .GE. 35 KT IN 36 HR): 14.2

INDIVIDUAL CONTRIBUTIONS TO INTENSITY CHANGE
6 12 18 24 36 48 60 72 84 96 108 120 132 144 156 168
------------------------------------------------------------------------------
SAMPLE MEAN CHANGE 0. 0. 1. 1. 1. 2. 1. 1. 0. -0. -1. -2. -3. -4. -4. -5.
SST POTENTIAL 0. 0. 1. 2. 6. 11. 17. 21. 25. 27. 29. 29. 30. 30. 30. 30.
VERTICAL SHEAR MAG 1. 1. 2. 3. 5. 6. 7. 8. 9. 10. 11. 12. 12. 11. 10. 9.
VERTICAL SHEAR ADJ 0. 1. 1. 1. 1. 1. 1. 0. 0. 0. -0. -0. -0. -0. 0. 0.
VERTICAL SHEAR DIR 0. 1. 2. 2. 2. 2. -1. -3. -5. -7. -7. -7. -7. -6. -5. -5.
PERSISTENCE 1. 1. 1. 2. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1.
200/250 MB TEMP. 0. 0. 0. 0. 1. 0. -0. -1. -2. -2. -2. -2. -3. -3. -3. -4.
THETA_E EXCESS 0. 0. 0. 0. 0. -0. -0. -1. -1. -2. -2. -3. -3. -3. -3. -3.
700-500 MB RH 0. 0. 0. 0. 0. 1. 1. 1. 1. 1. 1. 1. 1. 0. 0. 0.
MODEL VTX TENDENCY 0. 1. 1. 2. 3. 4. 6. 8. 8. 9. 9. 6. 4. 3. 1. -1.
850 MB ENV VORTICITY -0. -0. -0. -0. -0. -0. -0. -0. 0. 0. 0. 1. 1. 1. 1. 1.
200 MB DIVERGENCE 0. 0. 0. 0. 0. -0. -1. -1. -2. -2. -2. -2. -2. -1. -1. -0.
850-700 T ADVEC -0. -0. -0. -0. -0. -0. 0. -0. 0. 0. 0. 0. 1. 1. 1. 2.
ZONAL STORM MOTION -0. -0. -0. -1. -1. -1. -2. -2. -1. -1. -1. -1. -1. -1. -1. 0.
STEERING LEVEL PRES 0. 0. 1. 1. 1. 2. 2. 2. 2. 2. 2. 2. 2. 1. 1. 0.
DAYS FROM CLIM. PEAK -0. -0. -0. -0. -0. -0. -0. -0. -1. -1. -1. -1. -1. -1. -2. -2.
GOES PREDICTORS -0. -1. -1. -1. -1. -2. -3. -3. -4. -4. -5. -5. -5. -5. -4. -4.
OCEAN HEAT CONTENT -0. 0. 0. 0. 0. -0. -0. -0. -0. -0. -0. 0. 0. 1. 2. 3.
RI POTENTIAL 0. 0. 0. 1. 1. 0. -0. -0. 0. 0. 1. 1. 1. 1. 1. 1.
------------------------------------------------------------------------------
TOTAL CHANGE 3. 6. 10. 14. 21. 26. 28. 31. 32. 31. 32. 30. 28. 26. 26. 25.

CURRENT MAX WIND (KT): 30. LAT, LON: 13.9 119.4

** 2020 E. Pacific RI INDEX EP902020 INVEST 07/20/20 12 UTC **
(SHIPS-RII PREDICTOR TABLE for 30 KT OR MOREMAXIMUM WIND INCREASE IN NEXT 24-h)

Predictor Value RI Predictor Range Scaled Value(0-1) % Contribution
POT = MPI-VMAX (KT) : 121.0 40.5 to 149.3 0.74 7.2
12 HR PERSISTENCE (KT) : 5.0 -22.0 to 44.0 0.41 4.7
850-200 MB SHEAR (KT) : 6.6 19.6 to 1.4 0.72 6.4
D200 (10**7s-1) : 54.2 -33.0 to 160.6 0.45 4.2
MAXIMUM WIND (KT) : 30.0 22.5 to 132.0 0.21 1.5
STD DEV OF IR BR TEMP : 21.2 37.8 to 2.1 0.46 2.7
HEAT CONTENT (KJ/CM2) : 22.6 2.7 to 106.7 0.19 1.0
BL DRY-AIR FLUX (W/M2) : 131.2 800.8 to -82.5 0.76 -5.5
%area of TPW <45 mm upshear : 0.0 56.6 to 0.0 1.00 2.4
2nd PC OF IR BR TEMP : -0.3 2.2 to -1.9 0.61 0.4

SHIPS Prob RI for 20kt/ 12hr RI threshold= 12% is 1.9 times climatological mean ( 6.3%)
SHIPS Prob RI for 25kt/ 24hr RI threshold= 26% is 2.0 times climatological mean (12.6%)
SHIPS Prob RI for 30kt/ 24hr RI threshold= 25% is 2.9 times climatological mean ( 8.6%)
SHIPS Prob RI for 35kt/ 24hr RI threshold= 18% is 2.8 times climatological mean ( 6.2%)
SHIPS Prob RI for 40kt/ 24hr RI threshold= 0% is 0.0 times climatological mean ( 4.2%)
SHIPS Prob RI for 45kt/ 36hr RI threshold= 22% is 3.2 times climatological mean ( 6.7%)
SHIPS Prob RI for 55kt/ 48hr RI threshold= 21% is 3.6 times climatological mean ( 5.9%)
SHIPS Prob RI for 65kt/ 72hr RI threshold= 17% is 3.6 times climatological mean ( 4.7%)

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: 12.0% 25.6% 25.1% 17.6% 0.0% 21.7% 21.1% 16.8%
Logistic: 3.0% 14.4% 13.1% 6.1% 3.8% 16.5% 16.1% 31.7%
Bayesian: 0.5% 11.2% 3.0% 0.5% 0.2% 0.9% 1.2% 0.1%
Consensus: 5.2% 17.1% 13.7% 8.1% 1.3% 13.0% 12.8% 16.2%
DTOPS: 0.0% 5.0% 2.0% 1.0% 0.0% 3.0% 6.0% 14.0%

## ANNULAR HURRICANE INDEX (AHI) EP902020 INVEST 07/20/20 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) ##

[EquusStorm]

Aaaand we have a TD

Tropical Depression Eight-E Discussion Number 1
NWS National Hurricane Center Miami FL EP082020
500 AM HST Mon Jul 20 2020

Satellite imagery and overnight scatterometer data indicate that the
low pressure area to the southeast of Tropical Depression Seven-E
has a well-defined circulation and sufficient organized convection
to be considered a tropical depression. Thus, advisories are being
initiated on Tropical Depression Eight-E. The initial intensity is
30 kt based on the scatterometer data and a subjective Dvorak
intensity estimate from TAFB.

The initial motion is 240/6, with the depression being steered by a
portion of the subtropical ridge building between it and Tropical
Depression Seven-E. This motion should persist with some
increase in forward speed for 24-36 h, followed by a turn toward
the west as the steering flow becomes more easterly. This should
be followed by a turn toward the west-northwest after 60h. The
track guidance is in good agreement on this scenario, and the NHC
forecast is in the middle of the guidance and close to the various
consensus models.

The cyclone is over warm sea surface temperatures and in a light
shear environment, and these conditions should persist for the next
several days. The intensity guidance calls for steady
strengthening through about 72 h, and the NHC forecast follows this
trend near the upper edge of the intensity guidance envelope.
The Rapid Intensification Indices of the SHIPS model suggest about
a 20-25 percent chance of RI during the first 72 h of the
forecast, so it is possible that the cyclone will strengthen more
than currently forecast.


FORECAST POSITIONS AND MAX WINDS

INIT 20/1500Z 13.7N 119.8W 30 KT 35 MPH
12H 21/0000Z 13.1N 121.0W 35 KT 40 MPH
24H 21/1200Z 12.4N 123.1W 40 KT 45 MPH
36H 22/0000Z 11.8N 125.7W 45 KT 50 MPH
48H 22/1200Z 11.7N 128.4W 55 KT 65 MPH
60H 23/0000Z 11.9N 131.1W 65 KT 75 MPH
72H 23/1200Z 12.7N 134.0W 70 KT 80 MPH
96H 24/1200Z 14.5N 139.5W 70 KT 80 MPH
120H 25/1200Z 16.5N 145.5W 60 KT 70 MPH

$$
Forecaster Beven

[ElectricStorm]

Hey we may finally get the first hurricane over here... Then again that's what we thought with Cristina so we never know...

[aspen]

NHC is going with a peak of 70 kt, so it’ll probably end up at 50-60 kt.

[TheStormExpert]

NHC is going with a peak of 70 kt, so it’ll probably end up at 50-60 kt.

Would be nice if the East Pacific could set at least one record.

[hurricanes1234]

Forecast peak of 70 knots.

Me: ohhh we might get our first EPAC hurricane of the year!
Also me: laughs in 2020

[aspen]

Looks like there’s a pocket of >20 kt shear right in its path, and it’s currently increasing. I’m betting this is going to get torn to shreds before it even has the chance to near hurricane status.

[Yellow Evan]

TXPZ25 KNES 201806
TCSENP

A. 08E (NONAME)

B. 20/1730Z

C. 13.4N

D. 119.8W

E. THREE/GOES-W

F. T2.0/2.0

G. IR/EIR/VIS

H. REMARKS...3/10 WHITE BANDING RESULTED IN A DT OF 2.0. MET AND PT
ARE 2.0. FT IS BASED ON DT.

I. ADDL POSITIONS

NIL


...ZHU

[Kingarabian]

Looks like there’s a pocket of >20 kt shear right in its path, and it’s currently increasing. I’m betting this is going to get torn to shreds before it even has the chance to near hurricane status.

Mid level shear, the shear that really bothers TC systems seems to be non existent though in the next 72 hours.

[Kingarabian]

12z Euro continues to show Hawaii impacts with a 50kt TS hitting Kona/South Big Island. Peaks it @ 978mb in 96 hours.
12z UKMET is the strongest showing it peaking @ 977mb in 96 hours.
12z CMC continues to develop this making it a Cat.1 hurricane but weakens it on approach and attempts to take it on a path that would bring it to the northern coasts of Hawaii.

12z GFS doesn't develop it.

[Kingarabian]

[Kingarabian]

Although it's still early there are indication that a stronger system means more northern motion and a weaker system continues west. Today's ensemble runs are hinting that a stronger system can potentially round the Subtropical Ridge and bring effects north of the islands. While a weaker shallower system will likely duck to the south.

12z EPS:

[Yellow Evan]

Hard to buy a true north of Hawaii track in late July in a year like this.

[cycloneye]

Tropical Depression Eight-E Discussion Number 2
NWS National Hurricane Center Miami FL EP082020
1100 AM HST Mon Jul 20 2020

Satellite imagery indciates that Tropical Depression Eight-E is
getting better organized, with the formation of a small central
dense overcast and banding features outside of the central
convection. Satellite intensity estimates are 35 kt from TAFB and
30 kt from SAB, and recent scatterometer data indciate winds near
30 kt in the northwester quadrant. Based on these data, the
initial intensity remains a possibly conservative 30 kt.

The initial motion is 235/6, with the depression still being
steered by a portion of the subtropical ridge building between it
and Tropical Depression Seven-E. This motion should persist with
some increase in forward speed for 24-36 h, followed by a turn
toward the west as the steering flow becomes more easterly. This
should be followed by a turn toward the west-northwest between
48-60 h. The track guidance remains in good agreement on this
scenario, and the NHC forecast is again in the middle of the
guidance and close to the various consensus models.

The cyclone is over warm sea surface temperatures and in a light
shear environment, and these conditions should persist for the next
several days. The intensity guidance calls for steady
strengthening through about 72 h, and the NHC forecast follows this
trend near the upper edge of the intensity guidance envelope.
The Rapid Intensification Indices of the SHIPS model suggest about
a 20-25 percent chance of RI during the first 72 h of the
forecast, and given the seemingly-favorable environment it would
not be a surprise if the cyclone strengthened more than currently
forecast.


FORECAST POSITIONS AND MAX WINDS

INIT 20/2100Z 13.5N 120.4W 30 KT 35 MPH
12H 21/0600Z 12.8N 121.7W 35 KT 40 MPH
24H 21/1800Z 12.1N 123.9W 40 KT 45 MPH
36H 22/0600Z 11.9N 126.6W 50 KT 60 MPH
48H 22/1800Z 11.9N 129.4W 60 KT 70 MPH
60H 23/0600Z 12.4N 132.1W 70 KT 80 MPH
72H 23/1800Z 13.4N 134.9W 75 KT 85 MPH
96H 24/1800Z 15.0N 140.0W 70 KT 80 MPH
120H 25/1800Z 16.5N 145.5W 60 KT 70 MPH

$$
Forecaster Beven

[Chris90]

Looking at microwave, I think they're underestimating the intensity. The microwave presentation is something recon would find 50-60kts with in the ATL, I think this deserves a name and has for awhile now.

[aspen]

Starting to develop an eyewall, it seems.