2020 EPAC Season

[Yellow Evan]

 https://twitter.com/webberweather/status/1261965392165158912

[Kingarabian]

PC: Ben Noll

Looking at NCAR reanalysis, even during cool Neutral or La Nina years, this setup more often than not, has been favorable for TC development in the EPAC.

[Yellow Evan]

https://i.imgur.com/RK7jzA2.jpg
PC: Ben Noll

Looking at NCAR reanalysis, even during cool Neutral or La Nina years, this setup more often than not, has been favorable for TC development in the EPAC.

Yea it’s a setup that’s ripe for above average activity from 100W-120W which can lead to mildly prolific seasons or parts of a season, depending how long such pattern lasts. And it wouldn’t shock me if the season exceeds expectations because of this.

[Yellow Evan]

 https://twitter.com/tropicaltracker/status/1262146156827742211

[cycloneye]

All the signals point for something to form soon.

 https://twitter.com/webberweather/status/1262359461290745857

[aspen]

All the signals point for something to form soon.

https://twitter.com/webberweather/status/1262359461290745857

SSTs are pretty toasty down where the enhanced precipitation is forecast, so perhaps we could see an early season major hurricane in the EPac. Also, wouldn’t this setup potentially support development in the western Atlantic as well?

[Yellow Evan]

 https://twitter.com/webberweather/status/1262360635435778050

[cycloneye]

Does anyone has the NOAA forecast for EPAC? I can't find it.

[hurricanes1234]

I found it on Wikipedia.

It says NOAA predicts 11-18 named storms, 5-10 hurricanes and 1-5 major hurricanes.

They said activity may be normal or below-normal because of cooler waters in the EPAC and the possibility of ENSO-neutral or La Niña.

https://en.m.wikipedia.org/wiki/2020_Pacific_hurricane_season

[TheStormExpert]

I found it on Wikipedia.

It says NOAA predicts 11-18 named storms, 5-10 hurricanes and 1-5 major hurricanes.

They said activity may be normal or below-normal because of cooler waters in the EPAC and the possibility of ENSO-neutral or La Niña.

https://en.m.wikipedia.org/wiki/2020_Pacific_hurricane_season

That's a wide-range!

It could go anywhere from a season like 2003 or 2010 which were well below-normal for East Pacific standards to a season above average. Talk about little confidence.

[Yellow Evan]

I found it on Wikipedia.

It says NOAA predicts 11-18 named storms, 5-10 hurricanes and 1-5 major hurricanes.

They said activity may be normal or below-normal because of cooler waters in the EPAC and the possibility of ENSO-neutral or La Niña.

https://en.m.wikipedia.org/wiki/2020_Pacific_hurricane_season

That's a wide-range!

It could go anywhere from a season like 2003 or 2010 which were well below-normal for East Pacific standards to a season above average. Talk about little confidence.

IIRC the CPC range is a standard deviation from their expected number and doesn't vary from year to year.

[Yellow Evan]

Outlook itself: https://www.cpc.ncep.noaa.gov/products/ ... icane.html

Most interesting bit is it seems to imply the active era in this basin ended.

The predicted SST anomaly patterns indicate near-average SSTs across the eastern Pacific hurricane region, and above-average SSTs across the Atlantic MDR. These conditions project onto the negative phase of the Pacific Decadal Oscillation (PDO) and also onto the warm phase of the Atlantic Multi-Decadal Oscillation (AMO). Historically, this combination of climate patterns tends to be associated with low-activity eras, and with near- or below-normal eastern Pacific hurricane seasons. However, a main source of uncertainty for the 2020 outlook is whether the negative PDO pattern will persist through the hurricane season.

In addition to year-to-year fluctuations, eastern Pacific hurricane activity exhibits strong variability on decadal and multi-decadal time scales. Periods of increased activity (such as 1982-94 and 2014-19) are called high-activity eras, and periods of decreased activity (such as 1971-1981 and 1995-2013) are called low-activity eras. The differences in seasonal activity between these two eras are considerable.

[CyclonicFury]

The PDO/PMM doesn't look nearly as negative as a couple months ago. I'm expecting a season more like 2017/2019 than something like 2007/2010. I'm thinking somewhere around 15-7-3 for this basin.

[hurricanes1234]

Outlook itself: https://www.cpc.ncep.noaa.gov/products/ ... icane.html

Most interesting bit is it seems to imply the active era in this basin ended.

The predicted SST anomaly patterns indicate near-average SSTs across the eastern Pacific hurricane region, and above-average SSTs across the Atlantic MDR. These conditions project onto the negative phase of the Pacific Decadal Oscillation (PDO) and also onto the warm phase of the Atlantic Multi-Decadal Oscillation (AMO). Historically, this combination of climate patterns tends to be associated with low-activity eras, and with near- or below-normal eastern Pacific hurricane seasons. However, a main source of uncertainty for the 2020 outlook is whether the negative PDO pattern will persist through the hurricane season.

In addition to year-to-year fluctuations, eastern Pacific hurricane activity exhibits strong variability on decadal and multi-decadal time scales. Periods of increased activity (such as 1982-94 and 2014-19) are called high-activity eras, and periods of decreased activity (such as 1971-1981 and 1995-2013) are called low-activity eras. The differences in seasonal activity between these two eras are considerable.

Excellent outlook highlighting all the parameters and reasonings behind the forecasts, as well as extremely useful information about the influence of decadal and multi-decadal features on seasonal activity.

[StruThiO]

Confidence is not high that the negative PDO pattern will persist through the hurricane season. One reason is that SST forecasts made several months ahead tend to have limited skill. Another reason is that the current negative PDO signal partly reflects the synoptic-scale wind and pressure patterns associated with a highly-amplified High pressure system over the middle latitudes of the North Pacific. Therefore, the current conditions are not necessarily a longer-term transition to the negative PDO. These observations lead to larger uncertainty about the nature of the background climate signal upon which the ENSO signal will overlay during the peak months of the 2020 eastern Pacific hurricane season.

[cycloneye]

12z GFS leans to the East Pacific side with the CAG.

[aspen]

12z GFS leans to the East Pacific side with the CAG.

https://i.imgur.com/PuRmGQ1.jpg

It also forms a second system a little off to the west, and then tries to form a third in the Caribbean. The GFS loves this CAG.

[cycloneye]

Looks like things will start to evolve in this basin fairly soon according to the models.

12z GFS begins development as early as next Wednesday.

[cycloneye]

Looks like things will start to evolve in this basin fairly soon according to the models.

12z GFS begins development as early as next Wednesday.

https://i.imgur.com/TpCjsmq.gif

NHC is not in a hurry.

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 AM PDT Sat May 23 2020

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

Tropical cyclone formation is not expected during the next 5 days.

$$
Forecaster Zelinsky

[DorkyMcDorkface]

000
ABPZ20 KNHC 242310
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 PM PDT Sun May 24 2020

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

A broad area of low pressure is expected to form later this week a
few hundred miles south of the coasts of southern Mexico, Guatemala,
and El Salvador. Conditions appear favorable for some development
of this system while it moves little or drifts northward through
the end of the week.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...20 percent.

$$
Forecaster Berg