2017 EPAC Season

[Yellow Evan]

ECMWF at 0z doesn't kill it, but I agree if it's track setup occurs it won't be anything more than a weak TS. While development odds are decreasing, I think if this doesn't happen, it will be changes to the synoptic pattern rather than convective feedback. Also worth noting that ECMWF has underdone the effects of a GOT gap event in the past, *cough* Patricia *cough*.

12z ECMWF rolling through as I type this.

[Yellow Evan]

000
ABPZ20 KNHC 061840
TWOEP

Special Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1140 AM PDT Sat May 6 2017

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

An area of low pressure is expected to form by early next week
over the far eastern Pacific to the south of El Salvador and
Honduras. Environmental conditions are forecast to be favorable for
gradual development, and a tropical depression could form by the
middle of next week while the low moves slowly toward the northwest.
The next Special Tropical Weather Outlook will be issued by 12 PM
PDT Sunday afternoon.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...medium...50 percent.

&&

Forecaster Blake

[Alyono]

EC dropped this entirely

I'm thinking a 30 percent chance of development at most. Not that impressed. Mainly MU developing this, and it tends to develop 10 of the next 2 storms

[Kingarabian]

EC dropped this entirely

I'm thinking a 30 percent chance of development at most. Not that impressed. Mainly MU developing this, and it tends to develop 10 of the next 2 storms

Just like last year. Models show development and then they drop it. And this had EPS and GEFS support the whole way.

[TheStormExpert]

EC dropped this entirely

I'm thinking a 30 percent chance of development at most. Not that impressed. Mainly MU developing this, and it tends to develop 10 of the next 2 storms

If every TC the GFS showed formed we would have our hands quite full year-round!

[weathaguyry]

IF a respectable hurricane were to form out of this (which is much less likely now) Would it possibly cause a considerable amount of upwelling, and cool off the ocean?

[Yellow Evan]

IF a respectable hurricane were to form out of this (which is much less likely now) Would it possibly cause a considerable amount of upwelling, and cool off the ocean?

Depends on track. If this stalls, yes it would cool off the ocean for a few weeks, but would recover quickly.

[Kingarabian]

IF a respectable hurricane were to form out of this (which is much less likely now) Would it possibly cause a considerable amount of upwelling, and cool off the ocean?

What do you mean by ocean? The waters directly under the hurricane or the region in which it is in?
For waters at the surface to cool because of a hurricane it depends on how fast the storm is moving, and how deep warm waters are. If a storm is moving very slowly, you will see a pretty good amount of upwelling within its vicinity. Even if they move at a fast pace, major hurricanes can leave a cold wake in their path. Initially you will see water temps cool, but if there are sufficient warm waters at the depth they'll recover usually in a short period of time. But hurricanes by themselves cannot cause a whole region (Nino regions, etc) to cool considerably and nor are they able to change the status quo of things in regards to water temps. However, it has been documented that typhoons in the WPAC (and only in the WPAC) near the equator can spawn WWB's in which those can help make water temperatures warm.

[Yellow Evan]

EC dropped this entirely

I'm thinking a 30 percent chance of development at most. Not that impressed. Mainly MU developing this, and it tends to develop 10 of the next 2 storms

If every TC the GFS showed formed we would have our hands quite full year-round!

I don't recall too many GFS phantom EPAC storms last year except for one around late May near 120W last year though.

[weathaguyry]

IF a respectable hurricane were to form out of this (which is much less likely now) Would it possibly cause a considerable amount of upwelling, and cool off the ocean?

What do you mean by ocean? The waters directly under the hurricane or the region in which it is in?
For waters at the surface to cool because of a hurricane it depends on how fast the storm is moving, and how deep warm waters are. If a storm is moving very slowly, you will see a pretty good amount of upwelling within its vicinity. Even if they move at a fast pace, major hurricanes can leave a cold wake in their path. Initially you will see water temps cool, but if there are sufficient warm waters at the depth they'll recover usually in a short period of time. But hurricanes by themselves cannot cause a whole region (Nino regions, etc) to cool considerably and nor are they able to change the status quo of things in regards to water temps. However, it has been documented that typhoons in the WPAC (and only in the WPAC) near the equator can spawn WWB's in which those can help make water temperatures warm.

Sorry for not being clear, I was meaning the general area of the hurricane (about 3 degrees Lat. by 3 degrees Long.) of the actual hurricane. Based on the Models, this may stall for a few days, as a strengthening (Cat 2-3? Hurricane). I found this map that suggests that the warm water may be shallow.

[Kingarabian]

IF a respectable hurricane were to form out of this (which is much less likely now) Would it possibly cause a considerable amount of upwelling, and cool off the ocean?

What do you mean by ocean? The waters directly under the hurricane or the region in which it is in?
For waters at the surface to cool because of a hurricane it depends on how fast the storm is moving, and how deep warm waters are. If a storm is moving very slowly, you will see a pretty good amount of upwelling within its vicinity. Even if they move at a fast pace, major hurricanes can leave a cold wake in their path. Initially you will see water temps cool, but if there are sufficient warm waters at the depth they'll recover usually in a short period of time. But hurricanes by themselves cannot cause a whole region (Nino regions, etc) to cool considerably and nor are they able to change the status quo of things in regards to water temps. However, it has been documented that typhoons in the WPAC (and only in the WPAC) near the equator can spawn WWB's in which those can help make water temperatures warm.

Sorry for not being clear, I was meaning the general area of the hurricane (about 3 degrees Lat. by 3 degrees Long.) of the actual hurricane. Based on the Models, this may stall for a few days, as a strengthening (Cat 2-3? Hurricane). I found this map that suggests that the warm water may be shallow.

[img]http://www.aoml.noaa.gov/phod/dataphod1/work/HHP/NEW/athhp.gif[img]

Yeah if this disturbance develops and becomes a strong storm, it'll definitely cause a pretty good amount of up welling if it moves slowly. Which in turn will weaken the storm. We've seen this happen numerous times in the past couple of seasons in the EPAC. Models do a bad job in picking up on up-welling induced weakening.

[Alyono]

What do you mean by ocean? The waters directly under the hurricane or the region in which it is in?
For waters at the surface to cool because of a hurricane it depends on how fast the storm is moving, and how deep warm waters are. If a storm is moving very slowly, you will see a pretty good amount of upwelling within its vicinity. Even if they move at a fast pace, major hurricanes can leave a cold wake in their path. Initially you will see water temps cool, but if there are sufficient warm waters at the depth they'll recover usually in a short period of time. But hurricanes by themselves cannot cause a whole region (Nino regions, etc) to cool considerably and nor are they able to change the status quo of things in regards to water temps. However, it has been documented that typhoons in the WPAC (and only in the WPAC) near the equator can spawn WWB's in which those can help make water temperatures warm.

Sorry for not being clear, I was meaning the general area of the hurricane (about 3 degrees Lat. by 3 degrees Long.) of the actual hurricane. Based on the Models, this may stall for a few days, as a strengthening (Cat 2-3? Hurricane). I found this map that suggests that the warm water may be shallow.

[img]http://www.aoml.noaa.gov/phod/dataphod1/work/HHP/NEW/athhp.gif[img]

Yeah if this disturbance develops and becomes a strong storm, it'll definitely cause a pretty good amount of up welling if it moves slowly. Which in turn will weaken the storm. We've seen this happen numerous times in the past couple of seasons in the EPAC. Models do a bad job in picking up on up-welling induced weakening.

models cannot pick up on upwelling unless they are coupled ocean-atmosphere models. SSTs are fixed in atmospheric models

[Kingarabian]

Sorry for not being clear, I was meaning the general area of the hurricane (about 3 degrees Lat. by 3 degrees Long.) of the actual hurricane. Based on the Models, this may stall for a few days, as a strengthening (Cat 2-3? Hurricane). I found this map that suggests that the warm water may be shallow.

[img]http://www.aoml.noaa.gov/phod/dataphod1/work/HHP/NEW/athhp.gif[img]

Yeah if this disturbance develops and becomes a strong storm, it'll definitely cause a pretty good amount of up welling if it moves slowly. Which in turn will weaken the storm. We've seen this happen numerous times in the past couple of seasons in the EPAC. Models do a bad job in picking up on up-welling induced weakening.

models cannot pick up on upwelling unless they are coupled ocean-atmosphere models. SSTs are fixed in atmospheric models

I know I may be speaking in hindsight, but considering all the advanced algorithms and calculations that global models execute, they can't incorporate a correlation where a TC at major hurricane status moving less than 5 mph will cause the SST's to cool?

[Yellow Evan]

Yeah if this disturbance develops and becomes a strong storm, it'll definitely cause a pretty good amount of up welling if it moves slowly. Which in turn will weaken the storm. We've seen this happen numerous times in the past couple of seasons in the EPAC. Models do a bad job in picking up on up-welling induced weakening.

models cannot pick up on upwelling unless they are coupled ocean-atmosphere models. SSTs are fixed in atmospheric models

I know I may be speaking hindsight, but considering all the advanced algorithms and calculations that global models execute, they can't incorporate a correlation where a TC at major hurricane status moving less than 5 mph will cause the SST's to cool?

IIRC the HWRF and GFDL had this, and explains why they handled Blanca 15 better than the globals.

[Yellow Evan]

18z GFS further west in origin setup (so more like the ECMWF) and has it moving inland near the Mexican border.

[Kingarabian]

models cannot pick up on upwelling unless they are coupled ocean-atmosphere models. SSTs are fixed in atmospheric models

I know I may be speaking hindsight, but considering all the advanced algorithms and calculations that global models execute, they can't incorporate a correlation where a TC at major hurricane status moving less than 5 mph will cause the SST's to cool?

IIRC the HWRF and GFDL had this, and why they handled Blance 15 better than the globals.

Yeah, exactly. What's ironic is that they use a lot from the GFS yet the GFS can't do the same.

[Alyono]

models cannot pick up on upwelling unless they are coupled ocean-atmosphere models. SSTs are fixed in atmospheric models

I know I may be speaking hindsight, but considering all the advanced algorithms and calculations that global models execute, they can't incorporate a correlation where a TC at major hurricane status moving less than 5 mph will cause the SST's to cool?

IIRC the HWRF and GFDL had this, and explains why they handled Blanca 15 better than the globals.

those models are fully coupled models

[dexterlabio]

But the strong MJO signal is still expected to pass in this area, right? The Euro showed a strong cyclone developing in the WPAC 2 weeks ago, it's been showing that for 2 or 3 runs then dropped the scenario entirely. Could this be due to the MJO signal being overestimated?

[Yellow Evan]

But the strong MJO signal is still expected to pass in this area, right? The Euro showed a strong cyclone developing in the WPAC 2 weeks ago, it's been showing that for 2 or 3 runs then dropped the scenario entirely. Could this be due to the MJO signal being overestimated?

In this case, it's at least partially synotpic, but the GFS has a tendency to overdo/move the MJO too fast, and the former also sometimes applies to the ECMWF.

[Kingarabian]

00z Euro brings it back, decent cat.2 on this run.

00z GFS stronger this run.

I'd bump the odds higher at this point. Development in 36 hours.