EPAC: JULIO - Remnants

[cycloneye]

Remnants of Nana.

90E INVEST 200904 1200 14.3N 94.7W EPAC 25 1007

[EquusStorm]

This is 60/60 now and rapidly regenerating, I guess everyone's focuses on the Atlantic lol

Sure wish the LLC had survived

[ClarCari]

From the Nana Thread:

Wonder if Nana might hold on long enough to cross over to the EPac intact - that would be very 2020 indeed.

And in very 2020 fashion for the EPAC, it will fizzle the moment it touches that water

IF this ends up developing I’ll eat my words after all,....but it still looks like it’s got only a small window, so we’ll seeeee

[cycloneye]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 PM PDT Fri Sep 4 2020

For the eastern North Pacific...east of 140 degrees west longitude:

1. A well-defined low pressure system is located about 100 miles south
of the the southern coast of Mexico. The associated shower and
thunderstorm activity remains displaced well to the west of the
low. Although upper-level winds are forecast to inhibit further
development during the next couple of days, only a small
increase in thunderstorm activity near the surface center of
circulation could result in the formation of a tropical
depression. This system is expected to move generally
west-northwestward, near or along the southern coast of Mexico
during the next few days. Regardless of development, this system
could produce locally heavy rainfall along portions of the coast of
southwestern Mexico. Please consult products from your local
office.
* Formation chance through 48 hours...medium...60 percent.
* Formation chance through 5 days...medium...60 percent.

Forecaster Roberts

[EquusStorm]

Was organizing fast but kind of stalled in further doing so; certainly not guaranteed. It's an absolute dead zone out there on that side; if this doesn't develop who knows when we'll see something else out here.

[Darvince]

Well, it certainly has very strong convection out in front right now.

[Hypercane_Kyle]

Tropical Storm Nana -- er, Julio, has formed.

[SconnieCane]

Well I'll be. They were pretty adamant that conditions would not be favorable for Pacific regeneration of ex-Nana.

[ClarCari]

LMAO When the Atlantic has to donate some of it’s own to the starving EPAC

[Yellow Evan]

Why do all ex-ATL storms that re-develop in this basin look alike? (Rhetorical question but it's something I've noticed).

[Yellow Evan]

05/1730 UTC 16.1N 101.9W T1.0/1.0 90E -- East Pacific

[cycloneye]

Tropical Storm Julio Discussion Number 1
NWS National Hurricane Center Miami FL EP152020
400 PM CDT Sat Sep 05 2020

The mid-level remnants of Atlantic Hurricane Nana have moved
westward and west-northwestward off the southwestern coast of Mexico
while producing intermittent convection during the last few days. A
well-defined low formed about a day ago and ASCAT data indicates
that it has been producing tropical-storm-force winds for the past
12 h or so. During the past few hours there has also been an
increase in deep convection near the center of the low, and the most
recent Dvorak classification from TAFB was T-2.5, indicating that
the system is sufficiently well-organized to be considered a
tropical cyclone. Since the low-level center of Nana dissipated
inland over Central Atlantic, the new tropical storm is named Julio,
the tenth of the northern East Pacific season. The TAFB Dvorak
classification and 15Z ASCAT data are the basis for the 35 kt
initial intensity. Since the ASCAT explicitly showed 35 kt winds and
that instrument typically under-samples the maximum winds, it is
possible this intensity is a little conservative.

Most of the dynamical models do not acknowledge the existence of
tiny Julio in their initial conditions. Only the ECMWF and its
ensemble show a small well-defined low and it therefore is the
primary basis for the NHC track forecast. In general, Julio should
continue west-northwestward at a slower forward speed for the next
couple of days, steered by a mid-level ridge to the northeast. Julio
is forecast to become a shallow remnant low in a few days and should
slow down to a crawl before it dissipates early next week. Since the
forecast is based largely on one modeling system rather than the
typical NHC consensus approach, confidence in the track forecast is
fairly low.

The tropical storm will be affected by strong easterly wind shear
for the next day or two and little or no further strengthening is
likely during that time. Although the shear could decrease by early
next week, Julio will reach a drier and more stable environment in a
couple of days. It is therefore forecast to become a remnant low
within 60 h and dissipate shortly thereafter. The NHC forecast is
based on a blend of the ECMWF and the statistical DSHP and LGEM
models since the HWRF and the GFS-dependent HMON models do not
appear to have a good handle on the initial state of the system.


FORECAST POSITIONS AND MAX WINDS

INIT 05/2100Z 16.1N 102.7W 35 KT 40 MPH
12H 06/0600Z 16.9N 105.0W 40 KT 45 MPH
24H 06/1800Z 18.0N 107.5W 40 KT 45 MPH
36H 07/0600Z 19.0N 109.4W 35 KT 40 MPH
48H 07/1800Z 19.9N 110.6W 30 KT 35 MPH
60H 08/0600Z 20.5N 111.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 08/1800Z...DISSIPATED

$$
Forecaster Zelinsky

[Kingarabian]

LMAO When the Atlantic has to donate some of it’s own to the starving EPAC

The EPAC gets quite a bit of its TC origins from the Atlantic and Africa. Before, the narrative used to be that the EPAC provided favorable conditions for tropical waves that could not develop in the Atlantic due to poor conditions on that side.

[cycloneye]

Tropical Storm Julio Discussion Number 2
NWS National Hurricane Center Miami FL EP152020
1000 PM CDT Sat Sep 05 2020

Satellite imagery, including recently received microwave
overpasses, shows that Julio has changed little in organization
during the past several hours, with the small low-level circulation
center is located near the eastern edge of the small area of
central convection. The initial intensity remains 35 kt based on
continuity and a satellite intensity estimated from TAFB.

The initial motion is west-northwestward or 295/15 kt. The latest
global models runs continue to have trouble resolving Julio, but
overall the cyclone is embedded in an east-southeasterly flow on
the southwest side of a mid-level ridge. A general west-
northwestward motion should continue with a decrease in forward
speed until the system dissipates. The new forecast track again
leans more toward the ECMWF model, which does the best job of
resolving Julio.

The tropical storm will be affected by moderate to strong easterly
wind shear for the next day or two, and only sight strengthening is
likely during that time. While the shear is forecast to diminish
after 24-36 h, the cyclone will encounter a drier and more stable
air mass at that time, which should lead to the dissipation of the
small system. The new intensity forecast is unchanged from the
previous forecast, and it lies below the intensity consensus.


FORECAST POSITIONS AND MAX WINDS

INIT 06/0300Z 16.6N 104.2W 35 KT 40 MPH
12H 06/1200Z 17.5N 106.4W 40 KT 45 MPH
24H 07/0000Z 18.5N 108.7W 40 KT 45 MPH
36H 07/1200Z 19.4N 110.1W 35 KT 40 MPH
48H 08/0000Z 20.3N 110.8W 30 KT 35 MPH
60H 08/1200Z 21.1N 111.2W 20 KT 25 MPH...POST-TROP/REMNT LOW
72H 09/0000Z...DISSIPATED

$$
Forecaster Beven

[wxman57]

I've been trying to find Julio on satellite since yesterday. Supposedly, it's at the red crosshairs at 09z, NHC's position.

[drezee]

I've been trying to find Julio on satellite since yesterday. Supposedly, it's at the red crosshairs at 09z, NHC's position.

http://wxman57.com/images/Julio.JPG

I agree. Shortwave IR shows nothing

https://www.tropicaltidbits.com/sat/sat ... t=vis-swir

How do you upgrade a trough of low pressure to 45mph?

[wxman57]

Crosshairs mark the center at 09Z, four hours ago. Lat/Lon lines are 1 deg apart. Small area of squalls to the WNW is 140 nm from the crosshairs. If that's Julio, it's moving at 35 kts. Seriously, I cannot find any evidence of a TS in this satellite image.

[wxman57]

Looks like the NHC's 09Z position was off by about 2 deg longitude.

[cycloneye]

Tropical Storm Julio Discussion Number 5
NWS National Hurricane Center Miami FL EP152020
300 PM MDT Sun Sep 06 2020

Julio remains a compact tropical storm that is producing a small
area of deep convection near and to the west of the center. A
recent ASCAT-A overpass showed maximum winds around 30 kt, which was
lower than in previous passes. Based on that data and the latest
Dvorak classifications, the initial intensity is lowered to 35 kt.
The ASCAT data also suggest that the circulation of Julio is not as
well defined on the south side as it was earlier.

As mentioned in the previous discussion, Julio's future is
somewhat unclear. The ECMWF and UKMET models show Julio becoming
absorbed by a larger low just to its southwest in a couple of days.
Conversely, the GFS, HWRF, and HMON models show Julio being the
dominant feature, with the latter two aids even showing
strengthening. Since confidence is low on which scenario will play
out, it seems best to hold continuity for now, which ends up leaning
closer to the ECMWF/UKMET solutions. The NHC intensity forecast is
a little lower than the previous one given the lower initial
intensity.

The tropical storm is moving west-northwestward at about 17 kt.
Julio should continue to move westward to west-northwestward at a
fairly quick pace for another 12-24 hours. However, after that time,
a notable slow down should occur as the ridge over the eastern
Pacific breaks down and leaves the cyclone in weak steering
currents. The new NHC track forecast is adjusted to the south of
the previous one to come into better agreement with the latest
models.

FORECAST POSITIONS AND MAX WINDS

INIT 06/2100Z 19.3N 110.0W 35 KT 40 MPH
12H 07/0600Z 19.6N 112.3W 40 KT 45 MPH
24H 07/1800Z 19.7N 114.2W 40 KT 45 MPH
36H 08/0600Z 19.6N 115.4W 40 KT 45 MPH
48H 08/1800Z 19.4N 116.1W 35 KT 40 MPH
60H 09/0600Z 19.2N 116.7W 35 KT 40 MPH...POST-TROPICAL
72H 09/1800Z...DISSIPATED

$$
Forecaster Cangialosi

[cycloneye]

Tropical Depression Julio Discussion Number 6
NWS National Hurricane Center Miami FL EP152020
900 PM MDT Sun Sep 06 2020

Julio is losing organization. A small area of deep convection
remains near the assumed center, which is best identified by SSMIS
microwave data a few hours ago. However, Socorro Island, located
about 30 miles south of the center, never showed any westerly winds.
While it is possible the system has already opened up into a
trough, advisories are being continued on the assumption that the
island missed the small system's circulation. The initial wind
speed is set to 30 kt due to the decay in overall satellite
presentation.

The depression is moving westward at a slower speed than before,
roughly 11 kt. This motion is expected tomorrow at a slower
speed as a ridge breaks down to the north of the cyclone.
Afterwards, since the tropical cyclone is so small, a larger
surface low to the southwest of the system seems likely to weaken
Julio and then absorb the tropical cyclone in a couple of days.
Thus the track forecast is adjusted south of the previous one, and
the new intensity forecast is reduced as well. A plausible
alternative scenario is that overnight scatterometer data will show
that the system has already degenerated into a surface trough.


FORECAST POSITIONS AND MAX WINDS

INIT 07/0300Z 19.4N 111.3W 30 KT 35 MPH
12H 07/1200Z 19.5N 113.2W 30 KT 35 MPH
24H 08/0000Z 19.5N 114.7W 30 KT 35 MPH
36H 08/1200Z 19.3N 115.5W 25 KT 30 MPH
48H 09/0000Z...DISSIPATED

$$
Forecaster Blake