2021 WPAC Season

[Hayabusa]

SSTs that were upwelled by Surigae are now back to "normal"

[Kingarabian]

There is very good potential over the next 4 weeks for TC development over the WPAC. Especially by mid June, there will be a very good chance for a string of decent systems in the WPAC.

[euro6208]

Lowest pressure run so far from GFS. 930mb, barely misses Luzon, and slams it to Taiwan.

[euro6208]

.Western Micronesia for Palau and Yap...
Two broad surface troughs can be seen this morning, one is west of
Koror near 130E and another one west of Chuuk near 147E. An upper-
level trough reaches northeastward from a low northwest of Yap at
14N136E, passing near Saipan to another low southwest of Minami Tori
Shima at 22N153E. These features are anticipated to prolong
diffluent flow across far western Micronesia thru midweek next week.

Drier trades between the two surface troughs should usher in quieter
weather for Koror thru early this evening, and sustain it near Yap
today. Starting late this evening, showers and thunderstorms will
return as the second trough arrives. Uncertainty exists for next
week but the pattern will probably remain wet. Model guidance is
developing a near-equatorial trough across far western Micronesia
toward midweek next week. With a moderately strong MJO cycle
anticipated to arrive next week, broad circulations could form along
the near-equatorial trough. Therefore, significant rainfall and gusty
winds are possible next week.

[euro6208]

00z GFS deepens *Choi-wan* even more. 923 mb and landfalls over Luzon a bit weaker at 933 mb.

[euro6208]

GFS smelling Koguma mid to long range.

[Hayabusa]

Development is already within 7 days (or 5 days based on latest GFS) but then again I need more consistent runs or until the ECMWF caves, this could turn out like 96W (03W) again but we have MJO support this time.

[mrbagyo]

GFS has its phantom storm within the 200hr range yet EC and other guidance model are still showing nada.

[mrbagyo]

super long range but looks like GFS is showing another significant WWB towards the end of May.

[euro6208]

Here we go. 06z GFS has the TC developing in just 90 hours. Bottoms at 927 mb with a possible strike on Catanduanes.

[euro6208]

EURO has a disturbance in the SCS at the end of the run similar to GFS's timeframe of when it takes Choi-Wan into the SCS.

[euro6208]

NWS sides with the EURO on this one.

The short term forecast remains steady, with showers across the
region through the weekend. The long term forecast still has a lot
of unanswered questions. The GFS remains the most aggressive with
heavy showers through the week. The GFS also spins up a circulation
around Tuesday that it then quickly develops. The ECMWF and NAVGEM
also expect showers and thunderstorms, but unlike the GFS are much
less aggressive with the weather next week. Instead the ECMWF shows
a more realistic situation; with a near equatorial trough producing
convection for most of next week.

The most difficult part of the forecast cycle is that the GFS
solution, while unlikely, still needs to be watched. A moderate to
strong MJO event next week will increase westerlies near the equator
and strengthen convection in the region. The MJO, along with the
consistency of the GFS, does raise some concerns about possible
tropical development next week. Despite those concerns, conditions
still favor the ECMWF solution with unorganized showers and
thunderstorms for next week. For now the forecast remains rooted in
the ECMWF solution.

[euro6208]

Abundant amount of convection south of Guam to the precursor TC.

Nothing yet from EURO

GFS still very consistent.

[dexterlabio]

Abundant amount of convection south of Guam to the precursor TC.

Nothing yet from EURO

GFS still very consistent.

https://i.imgur.com/SFMX3Co.jpg

I think this stretch of convection is a manifestation of the westerly wind bursts in the region. So maybe, just maybe, the GFS is on to something that a potent system might emerge out of this WWB event.

[euro6208]

Significantly weaker on the 00z GFS run. Land proximity will likely determine how strong it gets. Peaks at 964 mb before a Catanduanes Island and traversing northern Visayas. Still nothing to snooze at.

[euro6208]

Looking ahead, GFS has 2 more significant TC's with the second developing around 300 hours and possibly a large monsoon like system.

[euro6208]

T-minus 72 hours.

[Kingarabian]

Recent 16 day EPS runs are beginning to show signs of TCG in about 10 days. Regardless of what the global models show, they all agree on a legit WWB event over the WPAC starting in 5 days or less. By default that will increase TCG chances across the basin.

[euro6208]

Looking like GFS is a huge bust.

18z came in considerably weaker and a continued decline. Peaks at 993mb with a track that would take it over Manila. Wouldn't be surprising if it never materializes.

EURO.

[euro6208]

Models have come
into better agreement late in the week with a monsoon-like trough
draped west-to-east near Koror Palau. Official forecast the second
half of the week follows a blend of the GFS and ECMWF with moderate
monsoon flow developing south of 5N by this weekend. Showery weather
with occasional thunderstorms is likely around the trough but do not
anticipate hazardous marine conditions or surf at this time. It is
noteworthy to mention that the GFS model spins up a TC well northwest
of Palau late this week. The origin of this phantom TC appears to be
a surface trough south of Chuuk. The GFS seems far too quick to
develop it out of a subtle little trough. It seems very implausible.
Overall consensus points to a better chance of tropical development
within the monsoon trough some time next week.