2021 EPAC Season

[cycloneye]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 PM PDT Thu May 27 2021

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

1. A broad area of low pressure located about one thousand miles south
of the southern tip of the Baja California peninsula is producing
some disorganized showers and thunderstorms. Environmental
conditions appear only marginally conducive for development of this
system as it moves westward or west-northwestward at about 10 mph
during the next several days.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...20 percent.

2. Another area of low pressure is expected to form several hundred
miles south of the coast of southeastern Mexico during the next few
days. Some gradual development of this system is possible as it
moves generally westward at 5 to 10 mph.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...30 percent.

Forecaster Reinhart/Beven

[JW-_-]

TC Genesis Summary Model consensus output initialized 2021052800

[Kingarabian]

06z GFS thinks its mid season:

[Kingarabian]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 PM PDT Thu May 27 2021

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

1. Shower activity associated with a broad area of low pressure
located about 900 miles south of the southern tip of the Baja
California peninsula has become a little more concentrated since
yesterday. Some additional slow development could occur during
the next few days as the system moves westward or west-northwestward
at about 10 mph.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...low...30 percent.

2. Another area of low pressure is expected to form several hundred
miles south of the coast of southeastern Mexico during the next few
days. Some gradual development of this system is possible as it
moves generally westward at 5 to 10 mph.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...30 percent.

Forecaster Beven

[cycloneye]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 AM PDT Fri May 28 2021

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

Shower activity has changed little in organization during the past
several hours in association with a broad area of low pressure
located about 950 miles south-southwest of the southern tip of the
Baja California peninsula. Some slow development of this system is
possible during the next few days while it moves westward
or west-northwestward at about 10 mph.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...low...30 percent.

A trough of low pressure is producing a large area of disorganized
showers and thunderstorms several hundred miles south of Acapulco,
Mexico. Some gradual development of this system is possible
during the next several days while it moves slowly westward or
west-northwestward.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...30 percent.

$$
Forecaster Cangialosi

[cycloneye]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 AM PDT Fri May 28 2021

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

Shower activity is limited in association with a broad area of low
pressure located about 1000 miles south-southwest of the southern
tip of the Baja California peninsula. This system is moving
west-northwestward at about 10 mph and some slow development is
possible during the next few days before it moves into a drier and
more stable airmass early next week.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...low...30 percent.

A trough of low pressure is producing a large area of disorganized
showers and thunderstorms several hundred miles south of Acapulco,
Mexico. Gradual development of this system is possible during the
next several days while it moves slowly west-northwestward to the
south of Mexico.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...medium...40 percent.

$$
Forecaster Cangialosi

[Yellow Evan]

12z GFS still showing 2 storms, with the 10/40 eventually recurving although weakening prior to landfall.

[Yellow Evan]

Last 2 ECMWF runs never show anything more than a low with either system.

[Kingarabian]

Latest model runs other than the GFS barely develop the 2-3 AOI's in the EPAC, but they don't drop the systems entirely. They just keep them weak. So the NHC odds are pretty good IMO.

Deep level shear is favorable:


The two NHC circled areas are moving into areas with decreasing mid level shear although its a very tight area:

[JW-_-]

Probs have been very consistent with Tropical Depression.

[Kingarabian]

00z GFS and CMC favoring the 2nd system much more now.

[JW-_-]

Just hoping we see at-lest one get to first base a (td). Then make it to a named ts for the basin.

[Kingarabian]

00z Euro keeps the first system weak but again develops the 2nd system:

[JW-_-]

It does see an increase in latent heat flux. So yeah keeps following here until all the seeds are gone.

[cycloneye]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 AM PDT Sat May 29 2021

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

A small cluster of showers and thunderstorms located about 1000
miles south-southwest of the southern tip of the Baja California
peninsula is associated with a weak area of low pressure. This
system is moving westward at 5 to 10 mph, and some slow development
remains possible over the next few days before it moves into a drier
and more stable airmass by early next week.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...low...30 percent.

A broad area of low pressure located several hundred miles south of
Acapulco, Mexico, is producing disorganized shower and thunderstorm
activity. Environmental conditions are expected to be conducive for
gradual development of this system during the next several days, and
a tropical depression could form by the middle of next week while
the system moves westward to west-northwestward at about 10 mph.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...medium...50 percent.

$$
Forecaster Berg

[cycloneye]

For the 20/50 one.

A. TROPICAL DISTURBANCE

B. 29/1130Z

C. 8.8N

D. 100.2W

E. THREE/GOES-W

F. T1.0/1.0

G. IR/EIR/SWIR

H. REMARKS...>2/10 FOR A DT=1.0. MET AND PT AGREE. FT IS BASED ON DT.

I. ADDL POSITIONS

NIL


...LEE

[Yellow Evan]

[cycloneye]

Code red.

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 AM PDT Sat May 29 2021

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

Shower activity associated with a weak area of low pressure located
about 1000 miles south-southwest of the southern tip of the Baja
California peninsula remains disorganized. This system is expected
to move generally westward at 5 to 10 mph into a drier and more
stable airmass during the next few days, and its chance of
development appears to be decreasing.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...20 percent.

A broad area of low pressure located several hundred miles south of
Acapulco, Mexico, continues to produce disorganized shower and
thunderstorm activity. However, environmental conditions are
expected to be conducive for development of this system during the
next several days, and a tropical depression is likely to form by
the middle of next week while the system moves westward to
west-northwestward at about 10 mph.
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 5 days...high...70 percent.

$$
Forecaster Berg

[cycloneye]

Invest 91E is up

[DorkyMcDorkface]

Hmmmm....(this is the 10/10, not 91E)