2017 WPAC Season

[1900hurricane]

You can now add Invest 90W to that image (between Noru and 10W/upgraded 98W). It's all kinda nuts honestly.

[dexterlabio]

Quite a role reversal in the latest GFS and Euro forecasts for the MJO. While both models suggest the active signal staying around Phase 5-6 over the next several days, GFS is showing the MJO signal really picking up. The Euro, on the other hand, is pretty much having the signal just outside the MJO "circle of death." Not sure how much this will affect the tropics for the next 1 or 2 weeks, but I think this will explain why the GFS right now is the most zealous one in developing (or overdeveloping) current and potential storms in the Western Pacific, most especially Noru.

[1900hurricane]

Heh.

[mrbagyo]

Heh.

I would say 99w has the biggest potential among them all.

Btw, the hot cauldron west of Marianas still remains largely untapped.

[1900hurricane]

I'd tend to agree, although I'm still not sure what to make of Noru yet. While there are a ton of systems out there, 99W is arguably the only typical WPac system strangely enough.

[euro6208]

The models sensing more development after all the mess that is currently out there with all of them at or above 20N.

[1900hurricane]

The monsoon low level jet makes it all the way to 50*N by tau 240 on the 12Z ECMWF. That's just ridiculous.

[euro6208]

Really impressive visible shot from NWS Guam.

[doomhaMwx]

We now have TS Roke... Already the 5th named storm to develop in the WPac this July, and the 7th so far this year

[mrbagyo]

Just like that, 2017 has already caught up with JMA's average number of named TC to date.

Average No. of TC to date (JMA) : 7.1
2017 : 7

We still have TD 08W and invest 99W...

[euro6208]

976
FXPQ60 PGUM 220919
AFDPQ

Area Forecast Discussion
National Weather Service Tiyan GU
600 PM ChST Sat Jul 22 2017

.Marianas Synopsis...
Radar and satellite show isolated showers and thunderstorms across
the Marianas, with the greatest concentration near Tinian and Saipan
and south of Guam. High cirrus clouds are streaming northward across
the region from deep convection south of Guam between 9N and 12N.
Trade winds have become gentle, and seas at the buoys are generally
between 3 and 4 ft.

&&

.Discussion...
The forecast is basically the same as previous, except have brought
in mostly cloudy skies and isolated thunderstorms this evening.
Models show trade winds collapsing over the next day or two as a
monsoon trough developing out west and northwest of the Marianas
turns our winds to southeast Sunday, south on Monday, and finally
to southwest by Thursday. While that often means showery weather
for the Marianas, in this case the trough will be setting up far
enough to the northwest to bring the dry ridge south of the trough
into the region. Thus, after mostly cloudy with isolated showers
and thunderstorms the next couple of days, drier conditions with
partly cloudy skies and isolated showers should set in by Tuesday
and persist through next weekend.

&&

.Marine...
Seas should remain generally at 3-5 ft the next week or so. But the
shift from a trade-wind regime to a monsoonal regime will cause the
east swell to slowly decrease later in the week while a minor
southwest swell comes in the last half of this week.

&&

.Eastern Micronesia...
Trade-wind convergence produced an area of scattered showers and
isolated thunderstorms over the eastern half of Micronesia. This
afternoon, satellite imagery showed scattered showers and isolated
thunderstorms over Pohnpei and Kosrae. Expect the scattered showers
and isolated thunderstorms to persist at Kosrae tonight. As the
area moves west, scattered showers and isolated thunderstorms will
develop over Pohnpei tonight and continue through Sunday. Another
area of trade-wind convergence will bring scattered showers and
isolated thunderstorms to Majuro Sunday night, and to Kosrae Monday
through Tuesday.

The showers and thunderstorms that pushed across Chuuk this morning
have dissipated, and weak high pressure will build over the area
through Sunday. Trade-wind convergence will produce areas of
scattered showers and isolated thunderstorms just south of Chuuk
through much of the coming week. The bulk of the showers will
remain south of Chuuk but will be close enough to produce isolated
showers and thunderstorms Sunday night through Thursday.

&&

.GUM WATCHES/WARNINGS/ADVISORIES...
GU...None.
Marianas Waters...None.

&&

$$

Middlebrooke/Ziobro

[doomhaMwx]

Tropical Depression 08W and Tropical Storm Roke
Approaching Southern China
NASA MODIS Imagery
07-22-2017 05:55 UTC

[euro6208]

The rest of the month should be fairly active.




Really strong Kelvin Wave and an MJO moving through likely helping to ramp up the increase in activity.

[1900hurricane]

The Himawari-8 outage to most of my normal sites is starting to get on my nerves.

[euro6208]

EURO develops 2 more high latitude systems right behind Noru.

GFS has multiple systems. Can't even count.

[doomhaMwx]

The NW Pacific basin, Monday morning...
Two Invest areas -- 90W and 99W
Two Tropical Storms -- Sonca and Kulap
One Typhoon -- Noru

COMS VIS Imagery
07-23-2017 11:00pm UTC

[mrbagyo]

how's our ACE now?

[1900hurricane]

how's our ACE now?

A little better, but still pretty sucky through the end of July 23rd (just crossed 10 units). We'll see where we stand after this current batch of storms subside, but there is a lot of ground to make up.

[dexterlabio]

GFS and Euro MJO forecasts place the active phase in Phase 5-6 within the next 7 days, but it looks like it will be staying around this spot for quite some time. The GFS is the most aggressive one further increasing the MJO amplitude. I wonder how this will affect the tropical activity in the Western Pacific.

[Kingarabian]

GFS and Euro MJO forecasts place the active phase in Phase 5-6 within the next 7 days, but it looks like it will be staying around this spot for quite some time. The GFS is the most aggressive one further increasing the MJO amplitude. I wonder how this will affect the tropical activity in the Western Pacific.

GFS has been fifty fifty with the MJO as late.