EPAC Tropical Action 2012

[wxmx]

I see Jorge lurking. Jorge, would you please weigh in?

You don't want me to weigh in, I'm sure.

[GaWx]

GFS runs:

Thu 12Z: southern Sinaloa 11/2

Thu 18Z: southern Sinaloa 10/29

Fri 0Z: southern Baja Sur 10/31 moving ENE

Fri 6Z: southern Baja Sur 10/29 moving NNE

Fri 12Z: southern Baja Sur 10/29 moving NNE

Fri 18Z: southern Sinaloa 10/30 moving NE

Sat 0Z: Jalisco 10/31 moving NE

Sat 6Z: northern Sinaloa 10/31 moving NE but unraveling

It does seem that the GFS is honing in on the end of Oct. as opposed to the start of Nov. Of course, the Euro has nothing.

[Ground Scouring]

Operational Euro still not showing a darn thing (as of the 00Z run). The EPAC's as clean as a whistle through Day 10. It's kind of weird that the GFS has been so consistently showing a really well-developed system whereas the Euro isn't even showing a pressure blip. It's another one of these cases where we'll just need to wait and see which model comes through with the goods.

GFS has been far better at nailing developing systems this year...and given teleconnections in the pattern, there is a very good chance that the GFS is on to something. Based upon the pattern, I expect one more major landfall in Mexico before the year is out. The statistics provided by Larry (GaWx) offer further solid support for this. Also, the upcoming pattern with a ridge over the Plains and a West-Coast trough strongly favors the climatological Sinaloa threat...in the same time frame in which the GFS develops its major East-Pacific cyclone.

(Of course, if my ideas re: the Caribbean system pan out, Josh, you may have a tough time choosing between the two. See my musings in the Atlantic thread re: a King 1950-like track for 99L.)

[GaWx]

GFS runs:

Thu 12Z: southern Sinaloa 11/2

Thu 18Z: southern Sinaloa 10/29

Fri 0Z: southern Baja Sur 10/31 moving ENE

Fri 6Z: southern Baja Sur 10/29 moving NNE

Fri 12Z: southern Baja Sur 10/29 moving NNE

Fri 18Z: southern Sinaloa 10/30 moving NE

Sat 0Z: Jalisco 10/31 moving NE

Sat 6Z: northern Sinaloa 10/31 moving NE but unraveling

Sat 12Z: southern Sinaloa 10/30 moving NE

It does seem that the GFS is honing in on the end of Oct. as opposed to the start of Nov. Of course, the Euro has nothing.

Sat 12Z GFS at 240 hrs.: southern Sinaloa 10/30 moving NE

[HurricaneJosh]

GFS has been far better at nailing developing systems this year...and given teleconnections in the pattern, there is a very good chance that the GFS is on to something. Based upon the pattern, I expect one more major landfall in Mexico before the year is out. The statistics provided by Larry (GaWx) offer further solid support for this. Also, the upcoming pattern with a ridge over the Plains and a West-Coast trough strongly favors the climatological Sinaloa threat...in the same time frame in which the GFS develops its major East-Pacific cyclone.

(Of course, if my ideas re: the Caribbean system pan out, Josh, you may have a tough time choosing between the two. See my musings in the Atlantic thread re: a King 1950-like track for 99L.)

Wow-- you sure are bullish Re: both threats. I hope you're right...

And just so you have it fore reference, here's my little table of all major landfalls on this side since 1949. As you can see, 8 of 10 happened in October, with a couple of the most severe ones-- including the great Cat 5 of 1959 and Kenna 2002-- occurring quite late in the month:

1957 No. 10 (22 Oct) - Sinaloa - Cat 4 (120 kt)

1959 Great Mexico Hurricane (27 Oct) - Jalisco - Cat 5 (140 kt)

1967 Olivia (14 Oct) - Baja California Sur - Cat 3 (110 kt)

1975 Olivia (25 Oct) - Sinaloa - Cat 3 (100 kt)

1976 Liza (01 Oct) - Sinaloa - Cat 3 (~100 kt)

1976 Madeline (08 Oct) - Guerrero - Cat 4 (125 kt)

1983 Tico (19 Oct) - Sinaloa - Cat 3 (110 kt)

1989 Kiko (27 Aug) - Baja California Sur - Cat 3 (960 mb/100 kt)

2002 Kenna (25 Oct) - Nayarit - Cat 4 (950 mb/120 kt)

2006 Lane (16 Sep) - Sinaloa - Cat 3 (954 mb/110 kt)

P.S. If ya count Jova 2011, which I'm not convinced wasn't a major, then you have 9 of 11 major landfalls in Oct.

GFS runs:

Thu 12Z: southern Sinaloa 11/2

Thu 18Z: southern Sinaloa 10/29

Fri 0Z: southern Baja Sur 10/31 moving ENE

Fri 6Z: southern Baja Sur 10/29 moving NNE

Fri 12Z: southern Baja Sur 10/29 moving NNE

Fri 18Z: southern Sinaloa 10/30 moving NE

Sat 0Z: Jalisco 10/31 moving NE

Sat 6Z: northern Sinaloa 10/31 moving NE but unraveling

Sat 12Z: southern Sinaloa 10/30 moving NE

It does seem that the GFS is honing in on the end of Oct. as opposed to the start of Nov. Of course, the Euro has nothing.

Sat 12Z GFS at 240 hrs.: southern Sinaloa 10/30 moving NE

Thanks, Larry! I love these little "score tables" your make.

The 12Z Euro is showing a little something near the Gulf of Tehuantepec around Day 8-10-- not much, but more than what it was showing before.

[Ground Scouring]

Wow-- you sure are bullish Re: both threats. I hope you're right...

And just so you have it fore reference, here's my little table of all major landfalls on this side since 1949. As you can see, 8 of 10 happened in October, with a couple of the most severe ones-- including the great Cat 5 of 1959 and Kenna 2002-- occurring quite late in the month:

1957 No. 10 (22 Oct) - Sinaloa - Cat 4 (120 kt)

1959 Great Mexico Hurricane (27 Oct) - Jalisco - Cat 5 (140 kt)

1967 Olivia (14 Oct) - Baja California Sur - Cat 3 (110 kt)

1975 Olivia (25 Oct) - Sinaloa - Cat 3 (100 kt)

1976 Liza (01 Oct) - Sinaloa - Cat 3 (~100 kt)

1976 Madeline (08 Oct) - Guerrero - Cat 4 (125 kt)

1983 Tico (19 Oct) - Sinaloa - Cat 3 (110 kt)

1989 Kiko (27 Aug) - Baja California Sur - Cat 3 (960 mb/100 kt)

2002 Kenna (25 Oct) - Nayarit - Cat 4 (950 mb/120 kt)

2006 Lane (16 Sep) - Sinaloa - Cat 3 (954 mb/110 kt)

P.S. If ya count Jova 2011, which I'm not convinced wasn't a major, then you have 9 of 11 major landfalls in Oct.

There is also a report in the 1975 Monthly Weather Review summary (p. 487) that Olivia 1975 produced winds, presumably measured, of 120 kt as it made landfall near Mazatlán, Sinaloa. These winds may have been sustained but were not verified, so the best track lists a peak and landfall intensity of 100 kt, based upon what are admittedly paltry reconnaissance data. Based upon the description, the aircraft does not appear to have even entered the eye due to turbulent conditions, so no central-pressure value is noted. However, the top-left satellite image from 2215Z/24 October, when the hurricane was officially ~95 kt in the best track, seems to indicate a much more intense system due to the relatively average eye diameter, which appears to be under 25 n mi, and the intense CDO with a very imposing outflow pattern. Also, the hurricane summary notes that some small villages nearer the eye than Mazatlán sustained a very significant hit. As no reanalysis has been done yet, I suspect Olivia was a Cat-4 (120 kt+) on 24 October and at landfall on 25 October.

[HurricaneJosh]

There is also a report in the 1975 Monthly Weather Review summary (p. 479) that Olivia 1975 produced winds, presumably measured, of 120 kt as it made landfall near Mazatlán, Sinaloa. These winds may have been sustained but were not verified, so the best track lists a peak and landfall intensity of 100 kt, based upon what are admittedly paltry reconnaissance data. Based upon the description, the aircraft does not appear to have even entered the eye due to turbulent conditions, so no central-pressure value is noted. However, the top-left satellite image from 2215Z/24 October, when the hurricane was officially ~95 kt in the best track, seems to indicate a much more intense system due to the relatively average eye diameter, which appears to be under 25 n mi, and the intense CDO with a very imposing outflow pattern. Also, the hurricane summary notes that some small villages nearer the eye than Mazatlán sustained a very significant hit. As no reanalysis has been done yet, I suspect Olivia was a Cat-4 (120 kt+) on 24 October and at landfall on 25 October.

Agreed, snowflake. When I was doing my research to create this list, I noticed the discrepancy between the MWR account (120 kt) and the final best-track fix before landfall (100 kt). The tiebreaker was the publication, Tropical Cyclones of the Eastern North Pacific Basin, 1949-2006, which indicates Olivia 1975 was a Cat-3 landfall-- so I went with 100 kt.

As you've pointed out, though, the EPAC data have not been reanalyzed, and I can certainly see this one being upgraded-- in which case, we'd have yet another example of a very severe landfall very late in the month.

[HurricaneJosh]

Cool pic of Olivia making landfall a little SE of Mazatlan just before 06Z 25 Oct 1975. Note the pinhole eye that's clearly visible on the coast-- lending some weight to the higher intensity estimate (Cat 4):

[GaWx]

GFS runs:

Thu 12Z: southern Sinaloa 11/2
Thu 18Z: southern Sinaloa 10/29
Fri 0Z: southern Baja Sur 10/31 moving ENE
Fri 6Z: southern Baja Sur 10/29 moving NNE
Fri 12Z: southern Baja Sur 10/29 moving NNE
Fri 18Z: southern Sinaloa 10/30 moving NE
Sat 0Z: Jalisco 10/31 moving NE
Sat 6Z: northern Sinaloa 10/31 moving NE but unraveling
Sat 12Z: southern Sinaloa 10/30 moving NE
Sat 18Z: southern Sinaloa or northern Nayarit 10/29 moving NE or ENE
Sun 0Z: northern Michoacan 10/29 moving ENE


Also, I've found per Wiki three sig. hurricanes (any of which could have been a major at landfall) during the 1800's hitting between 10/27 and 11/1 on the MX coast anywhere from Mazatian to Manzanillo:

Nov. 1, 1839: Mazatlan, Sinaloa
Nov. 1, 1840: San Blas, Nayarit
Oct. 27, 1881: Manzanillo, Colima; 950 mb/110 knots..so this was a major; Per Wiki, "This hurricane totally destroyed the city."

[HurricaneJosh]

Thanks, Larry! Cool to see this consistency from the GFS. I'm just waiting for the Euro to break in the direction of the GFS. It's frustrating that, as of 00Z, it's still showing essentially nothing. Grrr.

P.S. Cool info Re: those earlier cyclones-- I didn't know about them. (I'm actually surprised there are such specific data Re: the 1881 storm.)

[HurricaneJosh]

I'm trying to figure out if this is showing the cyclone rapidly filling as it approaches the coast, or simply unraveling after it makes landfall:

[phil882]

I'm trying to figure out if this is showing the cyclone rapidly filling as it approaches the coast, or simply unraveling after it makes landfall:

The model truncates after 192 hours, so the resolution creates the illusion the storm is much weaker than it actually is. Looking at the shear maps, it does look like the potential disturbance might be getting sheared at the 180 hour period, but again this is way far out to really have any sort of confidence in the deterministic solution.

[HurricaneJosh]

The model truncates after 192 hours, so the resolution creates the illusion the storm is much weaker than it actually is. Looking at the shear maps, it does look like the potential disturbance might be getting sheared at the 180 hour period, but again this is way far out to really have any sort of confidence in the deterministic solution.

Ah, duh. I didn't realize the resolution changes after 192 hr. OK, cool.

Do you think we might have an interesting situation developing? And what do you make of the big divergence between the GFS and the Euro on this? (The GFS has been consistently showing this feature for a few days now, whereas the Euro shows zilch.)

[Ground Scouring]

I think I will find this thread over more appealing over the next few days--simply because the Northeast weenies listen to model runs more than sanity or climatology.

FL & EPAC > NE

[HurricaneJosh]

I think I will find this thread over more appealing over the next few days--simply because the Northeast weenies listen to model runs more than sanity or climatology.

FL & EPAC > NE

Thoughts Re: this system that the GFS keeps showing?

[Ground Scouring]

Thoughts Re: this system that the GFS keeps showing?

The system is actually no longer a fantasy...there is a broad area of cyclonic low-level turning in existence near 13.5°N 96.5°W. There is actually a fair amount of instability in the region, even greater than in the Caribbean, thanks to a recent westerly wind burst decreasing OLR (outgoing long-wave radiation) anomalies and thereby helping surface flux. Already satellite imagery shows a nice cirrus fan emanating on the west side of the low-pressure center, and the MJO phase should support a strong anticyclone over the area for another four days. The region in which it is forming is the same region in which two of the major MX October landfalls--the Great Mexican hurricane of 1959 and Madeline 1976--developed, according to records within 150 n mi of the said coordinates. The digging trough over the Great Lakes should limit W movement and impart a WNW component within a few days, keeping the system well within the zone favored for major landfalls--i.e., within 250 n mi of the Mexican coastline. Upper-level conditions appear much better than what many of the earlier systems faced, thanks to stronger mid-level ridging to the northwest over the next several days. The NHC has placed a lemon of 20% over the area and mentions gradual development over the next few days:

TROPICAL WEATHER OUTLOOK

NWS NATIONAL HURRICANE CENTER MIAMI FL

500 PM PDT SUN OCT 21 2012

FOR THE EASTERN NORTH PACIFIC...EAST OF 140 DEGREES WEST LONGITUDE..

1. SHOWERS AND THUNDERSTORMS CONTINUE IN ASSOCIATION WITH AN ELONGATED

LOW PRESSURE SYSTEM LOCATED ABOUT 425 MILES SOUTH-SOUTHEAST OF

ACAPULCO MEXICO. SOME GRADUAL DEVELOPMENT OF THIS LARGE

DISTURBANCE IS POSSIBLE OVER THE NEXT FEW DAYS AS IT MOVES SLOWLY

WESTWARD. THIS SYSTEM HAS A LOW CHANCE...20 PERCENT...OF BECOMING

A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE

NEXT 48 HOURS.

$$

FORECASTER STEWART

NNNN

Based upon the much more favorable upper-air set-up and greater instability, with the added plus of climatology, I am 95% confident that this system will reach at least 90 kt during some portion of its life...with a >60% chance of becoming a major and a 50% chance of making landfall as one over or south of the latitude of Jalisco. Strong model consistency (over a period of 5+ days) in this region under this type of environment has sometimes proved to be an indicator of a significant cyclogenesis in October--I believe the formation of Kenna 2002 and several late majors like Rick 2009 were forecast well in advance by some global models which were showing a major hurricane 5+ days out.

[HurricaneJosh]

Cool. Thanks, snowflake.

Excitin' that we now have a Lemon. Can't wait until it's an invest and we get some tracks.

[Ground Scouring]

It certainly looks far more organized, and the environment far more favorable, than have 85% of the crap we have seen in the Atlantic since 2009.

[HurricaneJosh]

It certainly looks far more organized, and the environment far more favorable, than have 85% of the crap we have seen in the Atlantic since 2009.

Totally. The EPAC has actually had a good season-- a lot of quality storms-- although most of them were very early.

[GaWx]

Here is the GFS update going through the 18Z GFS of today (14+ straight modeled strikes on MX):

Thu 12Z: southern Sinaloa 11/2

Thu 18Z: southern Sinaloa 10/29

Fri 0Z: southern Baja Sur 10/31 moving ENE

Fri 6Z: southern Baja Sur 10/29 moving NNE

Fri 12Z: southern Baja Sur 10/29 moving NNE

Fri 18Z: southern Sinaloa 10/30 moving NE

Sat 0Z: Jalisco 10/31 moving NE

Sat 6Z: northern Sinaloa 10/31 moving NE but unraveling

Sat 12Z: southern Sinaloa 10/30 moving NE

Sat 18Z: southern Sinaloa or northern Nayarit 10/29 moving NE or ENE

Sun 0Z: northern Michoacan 10/29 unraveling?

Sun 6Z: Jalisco 10/31 unraveling?

Sun 12Z: Jalisco 10/31 unraveling?

Sun 18Z: Colima 10/31 unraveling?

It seems that this modeled storm was holding together through landfall much better when it was headed to Sinaloa. The last four runs suggest it may be starting to unravel just prior to landfall. Josh had mentioned this possibility earlier with regard to the 0Z Sun GFS. The shift southward coincided with the closer track of Invest 99L to the U.S. Might there be some kind of loose connection? I suppose so since 99L has been forecasted to be quite a sig. and large storm.

[HurricaneJosh]

Here is the GFS update going through the 18Z GFS of today (14+ straight modeled strikes on MX):

Thu 12Z: southern Sinaloa 11/2

Thu 18Z: southern Sinaloa 10/29

Fri 0Z: southern Baja Sur 10/31 moving ENE

Fri 6Z: southern Baja Sur 10/29 moving NNE

Fri 12Z: southern Baja Sur 10/29 moving NNE

Fri 18Z: southern Sinaloa 10/30 moving NE

Sat 0Z: Jalisco 10/31 moving NE

Sat 6Z: northern Sinaloa 10/31 moving NE but unraveling

Sat 12Z: southern Sinaloa 10/30 moving NE

Sat 18Z: southern Sinaloa or northern Nayarit 10/29 moving NE or ENE

Sun 0Z: northern Michoacan 10/29 unraveling?

Sun 6Z: Jalisco 10/31 unraveling?

Sun 12Z: Jalisco 10/31 unraveling?

Sun 18Z: Colima 10/31 unraveling?

It seems that this modeled storm was holding together through landfall much better when it was headed to Sinaloa. The last four runs suggest it may be starting to unravel just prior to landfall. Josh had mentioned this possibility earlier with regard to the 0Z Sun GFS. The shift southward coincided with the closer track of Invest 99L to the U.S. Might there be some kind of loose connection? I suppose so since 99L has been forecasted to be quite a sig. and large storm.

Hmmm. Is it unraveling, or is it just the lower-resolution model output at that time range?

Climatologically, it makes more sense for the Sinaloa cyclone to get sheared, since it's further N. Cyclones further S-- in Colima, etc.-- should be safer from all that.

[am19psu]

Hmmm. Is it unraveling, or is it just the lower-resolution model output at that time range?

Climatologically, it makes more sense for the Sinaloa cyclone to get sheared, since it's further N. Cyclones further S-- in Colima, etc.-- should be safer from all that.

It's getting sheared to hell as it approaches the Riviera

[HurricaneJosh]

It's getting sheared to hell as it approaches the Riviera

[Ground Scouring]

This is one of the few times I have seen a reliable global model (the GFS and its ensemble mean) insistently--for seven+ days--developing a significant TC in just a few days from a lemon that the NHC puts at just 10% during the same time frame. How anomalous is that?

Add the very negative NHC wording “development, if any...is expected to be slow to occur,” and the situation looks even more curious.

[HurricaneJosh]

This is one of the few times I have seen a reliable global model (the GFS and its ensemble mean) insistently--for seven+ days--developing a significant TC in just a few days from a lemon that the NHC puts at just 10% during the same time frame. How anomalous is that?

Yeah. It looks like the GFS is backing off a little from the interesting solution, though, doesn't it?

[Ground Scouring]

Yeah. It looks like the GFS is backing off a little from the interesting solution, though, doesn't it?

You are right...since no other reliable model suite has really latched on to the scenario vis-à-vis the GFS suite, and since the shortwave trough over the CONUS looks to be more amplified (leaving less of a weakness in its wake and keeping the EPAC lemon farther south), I think the threat of a significant MX landfall has decreased substantially, though a tropical storm at peak strength seems likely within about three days. However, due to the later development over cooler waters, I think a hurricane is no longer very probable, unfortunately, so unless a secondary TC develops in its wake, the EPAC looks done...as I do not see anything else developing before 31 October or later.

This set-up is really lamentable, now that Sandy looks to be what I secretly feared...another new-normal Atlantic TC.

[somethingfunny]

Dammit, Rosa.

[Ed Lizard]

Dammit, Rosa.

I remember the mid level remants of 1994's Hurricane Rosa. TS Rosa looks far less interesting.

Although, it has some impressively cold cloud tops associated with the amorphous blob.

[Ground Scouring]

An interesting factoid is that both the Atlantic (19 TCs) and the EPAC (17 TCs) have been nearly equally active and that the 2012 EPAC season is one of only seven since 1965--1965, 1969, 1975, 1977, 1979, 1980, and 1996--to have never seen a TC form W of 135°W (excluding the unnamed 1975 hurricane, which developed from an extratropical low in the Central North Pacific). 2012 in the EPAC also appears to be, since 1970, one of only four warm ENSO years, out of 13 such years, to have featured less than two Category-4+ hurricanes in the EPAC. (I am assuming here that we will see a weak Niño this year.)

[HurricaneJosh]

Game over.

Very disappointed with the EPAC in October. I was so hopeful, especially given the El Nino. But it was slim pickin's-- after a curiously awesome early season and a curiously dead mid-season.

Blah.