EPAC: DOUGLAS - Remnants

[CyclonicFury]

Is it just me, or do models have a bias of weakening TCs that approach Hawaii too slowly? It seems like there have been a lot of modeled storms that were expected to hit Hawaii as a bonafide TC that ended up being much weaker than expected.

[Kingarabian]

Is it just me, or do models have a bias of weakening TCs that approach Hawaii too slowly? It seems like there have been a lot of modeled storms that were expected to hit Hawaii as a bonafide TC that ended up being much weaker than expected.

They're usually spot on intensity wise. Sometimes they may show a system being too strong near Hawaii but that's usually pre-genesis or simple model storms. Their issue when it comes to Hawaii are the bogus landfalls. A lot of times they show impact only for it to not occur. But conditions ahead of it are actually pretty good considering the ENSO state and the shear that covers Hawaii -- with 26C waters, decent RH, 5-12kts of shear.

[Kingarabian]

Probably won't be much left when it reaches Hawaii. I highly doubt it will be stronger than Olivia and Darby in terms of wind speeds.

Certainly this is a favored scenario. The only reason why there's some uncertainty is due to the Euro/EPS/HMON/HWRF keeping it intact.

[Yellow Evan]

Probably won't be much left when it reaches Hawaii. I highly doubt it will be stronger than Olivia and Darby in terms of wind speeds.

Probably not but by Hawaii standards an Olivia or Darby is at least something.

[Kingarabian]

I'm thinking an Iselle type impact but not peak. Olivia's track was super weird.

[Kingarabian]

This MW pass shows that this is well ahead of Cristina IMO. This is very likely a hurricane and has been for sometime.
Eyewall is present and looks like it's been in some type of ERC pattern due to dry air.



Center is at 11.8N and 126.5W compared to the NHC fix, and right underneath that big blob of convection.

[cycloneye]

Tropical Storm Douglas Discussion Number 7
NWS National Hurricane Center Miami FL EP082020
500 PM HST Tue Jul 21 2020

This afternoon's satellite presentation reveals a tropical
cyclone that's struggling with the inhibiting factors from
mid-level dry air intrusion. Cloud tops near the center of
circulation have warmed considerably during the past few hours, and
the primary convective band in the east semicircle has become a bit
fragmented. A blend of an earlier SATCON of 52 kt, an ADT objective
estimate of 51 kt and a Dvorak satellite classification of T3.5
from both TAFB and SAB supports holding the initial intensity at 55
kt, although the aforementioned recent changes in the cloud
pattern may consider this as a bit generous.

The better performing HFIP HCCA and IVCN multi-model intensity
guidance still show Douglas shaking off the dry air invasion and
strengthening into a hurricane in 12 hours, and the official
forecast reflects this. The consensus intensity models and the
FV3/GFS SHIPS show the cyclone reaching a peak intensity in around
two days. Afterward, Douglas will be moving over 25-deg-C oceanic
temperatures and into stable air mass. These negative
contributions should, therefore, induce a slow weakening trend
through day 5.

The initial motion is estimated to be westward, or 270/12 kt within
the mid-tropospheric easterly steering flow provided by a
subtropical ridge anchored to the north of Douglas. This ridge is
forecast to gradually build westward in response to a retreating
large cut-off low near the Hawaiian Islands. As a result, Douglas
should progressively turn West-northwestward by late Wednesday.
and this general motion is forecast to continue for the remainder
of the 5-day forecast period. The official NHC forecast is quite
similar to the previous one with only a slight adjustment to the
right beyond 72 hours through 120 hours in order to conform to
the various consensus models.


FORECAST POSITIONS AND MAX WINDS

INIT 22/0300Z 12.1N 126.7W 55 KT 65 MPH
12H 22/1200Z 12.1N 128.5W 70 KT 80 MPH
24H 23/0000Z 12.6N 130.8W 80 KT 90 MPH
36H 23/1200Z 13.6N 133.2W 85 KT 100 MPH
48H 24/0000Z 15.1N 136.0W 90 KT 105 MPH
60H 24/1200Z 16.4N 138.8W 80 KT 90 MPH
72H 25/0000Z 17.5N 141.7W 70 KT 80 MPH
96H 26/0000Z 18.8N 147.3W 60 KT 70 MPH
120H 27/0000Z 19.4N 153.1W 50 KT 60 MPH

$$
Forecaster Roberts

[StruThiO]

lol

[Kingarabian]

2020 is the year of tropical storms with microwave eyes/eyewalls it seems.

[Yellow Evan]

I think I can call that 65 knots.

[Chris90]

I'm definitely ready to pull the trigger and call it a hurricane. Microwave presentation has been steadily improving. Douglas has more fight in him than all the other EPAC cyclones so far this year. I disagree with the NHC's current intensity analysis, but I do like their intensity forecast. I think 85-90kts is a decent expectation for right now. Might fall short, might exceed, but there's enough doubt either way.

Also, the increasing threat to Hawaii with model trends is interesting in a year like this. Talk about 2020 just continuing to do its own thing. I hope this falls apart before the islands, Hawaii can't handle the same kind of threats other areas can. The best storm of the season so far and it can't just be a guaranteed fish.

[Yellow Evan]

22/0530 UTC 12.1N 127.3W T3.5/3.5 DOUGLAS -- East Pacific

[Yellow Evan]

Why is SAB using an embedded center pattern?

TXPZ25 KNES 220605
TCSENP

A. 08E (DOUGLAS)

B. 22/0530Z

C. 12.1N

D. 127.3W

E. THREE/GOES-W

F. T3.5/3.5

G. IR/EIR/SWIR

H. REMARKS...>0.5 DEGREE EMBEDDED INTO MG FOR A
DT=4.0. MET=3.5. PT=3.5. FT IS BASED ON MET SINCE CLOUD FEATURES ARE
NOT CLEAR-CUT.

I. ADDL POSITIONS

NIL


...LEE

[Kingarabian]

It's looking pretty good now. Outflow is expanding to the north and south. Convection is blooming in all quadrants.

[Kingarabian]

Tropical Storm Douglas Discussion Number 8
NWS National Hurricane Center Miami FL EP082020
1100 PM HST Tue Jul 21 2020

The overall appearance of Douglas has changed little over the past
several hours. Satellite images show a continuation of dry air
trying to be worked out of the eastern portion of the cyclone's
circulation. The latest satellite intensity estimates from TAFB and
SAB indicate that the initial advisory intensity remains 55 kt.

The majority of intensity guidance continues to suggest that Douglas
will soon overcome the dry air that has been holding the cyclone
back from strengthening. And, the system is forecast to remain in a
favorable environment for intensification for the next day or so.
Beyond 36 h, the combination of cooler SSTs and dry air should
cause Douglas to slowly weaken. The latest NHC forecast is a blend
of the corrected consensus HCCA and the ICON and IVCN consensus
aids. Based on this forecast, Douglas should become a hurricane
sometime on Wednesday.

Douglas is moving westward at around 13 kt. The ridge to the north
of the cyclone is forecast to become oriented east-to-west while
building westward over the next day or so. This should induce a
gradual turn to the west-northwest along with a slight increase in
forward speed. This general west-northwest motion is then forecast
to continue through the remainder of the 5-day period. The model
guidance has trended a bit faster throughout the forecast period,
and the official forecast now lies in between the clustered
consensus aids and the previous official forecast.


FORECAST POSITIONS AND MAX WINDS

INIT 22/0900Z 11.9N 128.0W 55 KT 65 MPH
12H 22/1800Z 12.0N 129.9W 65 KT 75 MPH
24H 23/0600Z 12.9N 132.4W 80 KT 90 MPH
36H 23/1800Z 14.1N 135.1W 90 KT 105 MPH
48H 24/0600Z 15.5N 137.9W 85 KT 100 MPH
60H 24/1800Z 16.7N 140.9W 80 KT 90 MPH
72H 25/0600Z 17.8N 143.9W 70 KT 80 MPH
96H 26/0600Z 19.1N 149.7W 60 KT 70 MPH
120H 27/0600Z 19.8N 155.3W 50 KT 60 MPH

$$
Forecaster Latto

[Kingarabian]

First ADT Raw above 4.0:

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 9.0
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 22 JUL 2020 Time : 092032 UTC
Lat : 11:53:57 N Lon : 128:04:13 W


CI# /Pressure/ Vmax
3.3 / 997.8mb/ 51.0kt


Final T# Adj T# Raw T#
3.3 3.4 4.1

Center Temp : -63.4C Cloud Region Temp : -66.3C

Scene Type : UNIFORM CDO CLOUD REGION

[GCANE]

Glad to hear Hawaii is out of the woods concerning any Tsunami threat from the Aleutians quake.

[Kingarabian]

Glad to hear Hawaii is out of the woods concerning any Tsunami threat from the Aleutians quake.

Yeah. When I saw it on Twitter I was like WTF. Also glad none of the western CONUS states were impacted.

[NXStumpy_Robothing]

Current image of Douglas (10:10 UTC).

Douglas looks absolutely mean this morning. Might be beginning a phase of intensification - a lot of the dry air appears to have been filtered out over the past several hours.

[Kingarabian]

Current image of Douglas (10:10 UTC).
[url]https://i.imgur.com/8p6Lov4.png[url]
Douglas looks absolutely mean this morning. Might be beginning a phase of intensification - a lot of the dry air appears to have been filtered out over the past several hours.

Nice looking "moderate TS" ain't it. In the past few hours, dry air entrainment attempts have been quickly stopped.