CPAC: DARBY - Post-Tropical

[TropicalAnalystwx13]

Convection looks to making some sort of return, but now there's a large dry slot evident, albeit outside the inner core for now.

[Alyono]

This is getting VERY far north so far to the east. This would be unprecedented for this to have a significant impact on Hawaii.

Typically, you need systems no farther north than 12N this far east

Could be why EPS shifting north.

Because the GFS and the Euro are showing a dip in latitude similar to Flossing 2007.

I believe Flossie entered the CPAC south of 12N

This will enter close to 19

[Kingarabian]

This is getting VERY far north so far to the east. This would be unprecedented for this to have a significant impact on Hawaii.

Typically, you need systems no farther north than 12N this far east

Could be why EPS shifting north.

Because the GFS and the Euro are showing a dip in latitude similar to Flossing 2007.

I believe Flossie entered the CPAC south of 12N

This will enter close to 19

Sorry I meant as it approached the big Island from east.

[NDG]

Like I have been saying for a while now, the only hurricanes that could threaten Hawaii have been fantasies by both the Euro and GFS which have not come to fruition.

[Kingarabian]

Like I have been saying for a while now, the only hurricanes that could threaten Hawaii have been fantasies by both the Euro and GFS which have not come to fruition.

Well just because landfall does not occur it does not mean there was no threat.

A threat in my book is anything <= 500 miles from land. So the GFS and Euro have not been wrong in that regard.

Because say there's a storm in the gulf. Initially, you're going to be watching that storm regardless of its track because it's a threat.

[cycloneye]

HURRICANE DARBY DISCUSSION NUMBER 14
NWS NATIONAL HURRICANE CENTER MIAMI FL EP052016
800 PM PDT THU JUL 14 2016

Darby has become a little better organized during the past 6 hours
with a ragged 30-nmi-diameter eye having appeared within the central
dense overcast. Upper-level outflow has continued to expand in all
quadrants. The initial intensity has been increased to 80 kt based
on a blend of consensus subjective intensity estimates of T4.5/77 kt
from TAFB and SAB, and UW-CIMSS objective intensity estimates of 83
kt and 85 kt from AMSU and ADT, respectively.

Darby's initial motion estimate is 280/11 kt after smoothing through
some wobbles in the track. Otherwise, there is no significant change
to previous track or philosophy. The latest model guidance remains
in excellent agreement on Darby moving west-northwestward to
westward for the next 48 hours, followed by a turn to a more due
west motion after that as the ridge to the north of the hurricane
builds slightly southward and westward. The new NHC track forecast
is basically just an extension of the previous advisory track, and
remains near the southern edge of the guidance suite, following the
consensus of the GFS and ECMWF models.

Although the vertical wind shear is expected to remain 10 kt or
less throughout the 5-day forecast period, SSTs decreasing below
27C and the large eye of Darby argue against any significant
strengthening during the next day or so. After that, SSTs
decreasing to less than 26C should induce gradual weakening by 36 h
and beyond. However, the aforementioned weak wind shear conditions
should act to prevent a more typical rapid weakening trend from
occurring. This is similar to the slower-than-normal weakening trend
noted with Tropical Storm Celia during the past couple of days while
that cyclone has been moving through a similar environment of low
shear and cool waters near 25C. The official NHC intensity forecast
is above the IVCN intensity consensus model, and closely follows a
blend of the SHIPS and LGEM models.

FORECAST POSITIONS AND MAX WINDS

INIT 15/0300Z 16.0N 119.1W 80 KT 90 MPH
12H 15/1200Z 16.4N 120.7W 85 KT 100 MPH
24H 16/0000Z 16.9N 122.7W 85 KT 100 MPH
36H 16/1200Z 17.4N 124.7W 80 KT 90 MPH
48H 17/0000Z 17.6N 126.5W 75 KT 85 MPH
72H 18/0000Z 18.1N 130.4W 65 KT 75 MPH
96H 19/0000Z 18.3N 135.1W 55 KT 65 MPH
120H 20/0000Z 18.6N 140.0W 50 KT 60 MPH

$$
Forecaster Stewart

[NDG]

Like I have been saying for a while now, the only hurricanes that could threaten Hawaii have been fantasies by both the Euro and GFS which have not come to fruition.

Well just because landfall does not occur it does not mean there was no threat.

A threat in my book is anything <= 500 miles from land. So the GFS and Euro have not been wrong in that regard.

Because say there's a storm in the gulf. Initially, you're going to be watching that storm regardless of its track because it's a threat.

But for a few "pros" to tweet about a model run 8 days from now hitting Hawaii as a hurricane is a bit irresponsible, IMO. Especially when is not the first time models have been too aggressive.

[Kingarabian]

Like I have been saying for a while now, the only hurricanes that could threaten Hawaii have been fantasies by both the Euro and GFS which have not come to fruition.

Well just because landfall does not occur it does not mean there was no threat.

A threat in my book is anything <= 500 miles from land. So the GFS and Euro have not been wrong in that regard.

Because say there's a storm in the gulf. Initially, you're going to be watching that storm regardless of its track because it's a threat.

But for a few "pros" to tweet about a model run 8 days from now hitting Hawaii as a hurricane is a bit irresponsible, IMO. Especially when is not the first time models have been too aggressive.

True. I think some just want the glory of being the first to call it. It's kind of similar to JB saying "East coast may be hit at the end of next month" "Watch out for the GOM in 2 weeks" etc. But I think it's all mostly harmless here on a discussion board.

[Kingarabian]

Dry air entrainment looks like it has decapitated the core:

[stormwise]

Just my thinking, just maybe the Big Island will get a clipper with Darby.


Full cyan ring usually means intensification.

[Kingarabian]

Just my thinking, just maybe the Big Island will get a clipper with Darby.


Full cyan ring usually means intensification.

It's 3:20Z right now. That pass is almost 5 hours old. The pass in my previous post is 2 hours old.

[Alyono]

annular within 24 hours

[1900hurricane]

I don't think it's a coincidence that every time new convection fires, it dies as soon as it rotates into the northern portion of the circulation. That's the part of the circulation that microwave has consistently shown entraining the dry air. It certainly could be worse, and Darby is doing a decent job mixing it out, and it does appear to be decreasing with time, bit it's definitely tampering with the convective profile for now. Without the dry air, we'd likely be dealing with a pretty salty hurricane right now.

[Yellow Evan]

The storm looks quite messy again, and convection is quite shallow on the eastern semicircle. Honestly can't see this doing much as SST's are only declining, although a storm of this intensity and structure isn't atypical for July.

[stormwise]

Just about roughly 16mins ago?, I'm with Alyono sticking to my guns.

[Kingarabian]

00z GFS shifted north. Expect this to trend to continue.

[Kingarabian]

Most I'd do go with is 65kts.


2 hours ago:

[stormwise]

looks a bit stronger to me 75/80 kts big centre those hold intensity can easily be underestimated.

[stormwise]

WTPZ35 KNHC 150838
TCPEP5

BULLETIN
HURRICANE DARBY ADVISORY NUMBER 15
NWS NATIONAL HURRICANE CENTER MIAMI FL EP052016
200 AM PDT FRI JUL 15 2016

...DARBY MOVING WESTWARD ACROSS THE EASTERN PACIFIC...


SUMMARY OF 200 AM PDT...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...16.1N 120.0W
ABOUT 805 MI...1300 KM SW OF THE SOUTHERN TIP OF BAJA CALIFORNIA
MAXIMUM SUSTAINED WINDS...90 MPH...150 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...982 MB...29.00 INCHES


WATCHES AND WARNINGS
--------------------
There are no coastal watches or warnings in effect.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
At 200 AM PDT (0900 UTC), the center of Hurricane Darby was located
near latitude 16.1 North, longitude 120.0 West. Darby is moving
toward the west near 12 mph (19 km/h). A turn toward the
west-northwest is expected later today, and this motion should
continue through Saturday.

Maximum sustained winds are near 90 mph (150 km/h) with higher
gusts. Some strengthening is possible today, with weakening
expected tonight and Saturday.

Hurricane-force winds extend outward up to 30 miles (45 km) from the
center and tropical-storm-force winds extend outward up to 115 miles
(185 km).

The estimated minimum central pressure is 982 mb (29.00 inches).


HAZARDS AFFECTING LAND
----------------------
None.


NEXT ADVISORY
-------------
Next complete advisory at 800 AM PDT.

$$
Forecaster Beven

[cycloneye]

HURRICANE DARBY DISCUSSION NUMBER 15
NWS NATIONAL HURRICANE CENTER MIAMI FL EP052016
200 AM PDT FRI JUL 15 2016

Darby has changed little in organization during the past several
hours, with satellite imagery showing a ragged 25 n mi wide eye
embedded in the central dense overcast. Subjective satellite
intensity estimates are 90 kt from TAFB and 77 kt from SAB, while
various objective estimates from CIMSS are in the 75-80 kt range.
Based on these data, the initial intensity remains at 80 kt.

The initial motion is 280/10. There is no change to the forecast
philosophy from the previous advisory, and there are no important
changes to the forecast track. The model guidance is in excellent
agreement that Darby will move generally west-northwestward for the
next 36-48 hours, followed by a more westward motion after, as the
subtropical ridge to the north of the hurricane builds slightly
southward and westward. The new NHC track remains just a little to
the south of the center of the guidance envelope.

Some strengthening is possible during the next 12 hours while the
center of Darby remains over relatively warm water. After that,
the forecast track takes the cyclone over decreasing sea surface
temperatures through 72-96 hours, possibly as cold as 24C. This
should cause significant weakening despite an otherwise favorable
shear environment. It is possible that Darby could weaken more than
currently forecast, as it appears that the sea surface temperatures
near 130W are colder than those used by the SHIPS model. After 96
hours, the forecast track takes the cyclone over sea surface
temperatures near 26C at the same time that it encounters a drier
air mass. Thus, slow weakening is expected to continue. The new
intensity forecast is slightly weaker than the previous forecast
and is in best agreement with the IVCN intensity consensus.


FORECAST POSITIONS AND MAX WINDS

INIT 15/0900Z 16.1N 120.0W 80 KT 90 MPH
12H 15/1800Z 16.5N 121.5W 85 KT 100 MPH
24H 16/0600Z 17.2N 123.5W 80 KT 90 MPH
36H 16/1800Z 17.6N 125.3W 75 KT 85 MPH
48H 17/0600Z 17.9N 127.0W 70 KT 80 MPH
72H 18/0600Z 18.5N 131.0W 60 KT 70 MPH
96H 19/0600Z 19.0N 135.5W 50 KT 60 MPH
120H 20/0600Z 19.0N 140.5W 45 KT 50 MPH

$$
Forecaster Beven