EPAC Tropical Action 2011

[wxmx]

What is cause and what is effect? Is more African waves becoming ATL TCs a significant factor, or just the fact that what is significant for high EPAC numbers also surpresses NATL numbers and vice versa.

Semi-related question, just found Origins and Mechanisms of Eastern Pacific Tropical Cyclogenesis: A Case Study on Google, what is the breakdown for TCs as far as originating from failed African waves from the Atlantic, the monsoon trough, and interactions between them.

There are other factors than the universe of TWs available. The ENSO have an inverse effect on both basins. In the Atlantic is mostly the upper atmosphere which is affected, on the EPac is both, the atmosphere and the SSTAs. Last season, for example, had a very persistent anticyclonic flow over the GOM/Caribbean/MX, which translated to furious easterly shear for anything that tried to develop close the the MX coast, which is one of the primary cyclogenesis areas of the EPac basin.

[aslkahuna]

Who didn't? The irony is that if we had late forecasts issued for the past season, say in late June, they would have even blew harder, very probably. Who would have said that after a record active June we would have a record inactive JASO. I got the progression of the season good (active to inactive), but I thought it was going to be more gradual.

Also too, October was totally dead in EPAC for the first time since 1995.

Steve

[wxmx]

Early start for the EPac? Looks like the MJO wants to bring the EPac and NAtl to life early in the season. Cyclogenesis is not that deep in fantasyland, but trip to Puerto Escondido/Acapulco is.

}

[Srain]

Early start for the EPac? Looks like the MJO wants to bring the EPac and NAtl to life early in the season. Cyclogenesis is not that deep in fantasyland, but trip to Puerto Escondido/Acapulco is.

}

And ends up in the BoC. Imagine that.

[k***]

25 days early wouldn't be too bad. I'm dying for something....anything...to form.

[Supercane]

25 days early wouldn't be too bad. I'm dying for something....anything...to form.

There is no record of an EPAC tropical storm forming before May 14, so development in April would actually be highly anomalous. Of course, the GFS pulled a similar stunt around this time last year as well, so I'm not holding my breath.

[HurricaneJosh]

25 days early wouldn't be too bad. I'm dying for something....anything...to form.

I can tell. You've been more mischievous than usual as of late.

[k***]

There is no record of an EPAC tropical storm forming before May 14, so development in April would actually be highly anomalous. Of course, the GFS pulled a similar stunt around this time last year as well, so I'm not holding my breath.

Now that you mention it, I have heard that before. It's kind of crazy that the earliest storm on record is one day before the official start of the season.

[k***]

I can tell. You've been more mischievous than usual as of late.

disagree...i'm hardly around these days (compared to normal)

[Supercane]

Now that you mention it, I have heard that before. It's kind of crazy that the earliest storm on record is one day before the official start of the season.

Yeah, the EPAC rarely strays outside its official boundaries. To add, the only recorded December EPAC storm was Hurricane Winnie in 1983.

This is probably because the only sources for development in the basin are the seasonally constrained ITCZ and tropical waves -- I can't recall any extratropical to (sub)tropical transitions in the EPAC, which is the origin of most offseason Atlantic storms.

[HurricaneJosh]

disagree...i'm hardly around these days (compared to normal)

Fewer posts, but a higher percentage of trollytroll posts.

[wxmx]

We, tropical dudes, are in an eternal loop. Same players, similar dates, same posts by the same people... even the Scott post shows almost what he was hotlinking at the time. Surreal

http://www.easternuswx.com/bb/index.php?/topic/229473-e-pacific-tropical-action-2010/page__view__findpost__p__4841967

[am19psu]

We, tropical dudes, are in an eternal loop. Same players, similar dates, same posts by the same people... even the Scott post shows almost what he was hotlinking at the time. Surreal

http://www.easternuswx.com/bb/index.php?/topic/229473-e-pacific-tropical-action-2010/page__view__findpost__p__4841967

Jesus. That's uncanny.

[HurricaneJosh]

Tradition ain't nothin' to be ashamed of.

[aslkahuna]

Tradition ain't nothin' to be ashamed of.

Except in Politics apparently. To expand upon EPAC for a moment, that West Coast trough tends to extend south fairly soon in the Fall setting up unfavorable environments for development. Usually it clears the monsoon out of Arizona in September and sets the stage for recurvature events. EPAC storms were often referred to as "Cordonazo de San Francisco" (the Lash of St. Francis) in Mexico for the simple reason that they always seemed to hit around the feast day of St. Francis which is in October. Most remnant hits in AZ have occurred in September and October though Lester hit us in late August in 1992. By November, we start to get upper troughs diving south off the CA coast and closing off off the SoCA or Baja Coasts with the trough digging well down into the lower latitudes. This usually triggers what I call a Banana Express or moisture plume event (or atmospheric river) into the SW which can dump a lot of rain. The champion in this regard happened on November 11 1994 when a ULL closed off off the Baja spur triggering a moisture plume from the equator into AZ. Three to eight inches of rain fell in 24 hours in Cochise County and the wind fields aloft were so strong that TS force winds occurred. But there was no TS or even remnant involved. The last storm to landfall in 1994 was H. Rosa which was picked up by a trough over AZ and sent into TX as a TD with the remnants spreading very heavy rains into the Plains.

Steve

[Supercane]

We, tropical dudes, are in an eternal loop. Same players, similar dates, same posts by the same people... even the Scott post shows almost what he was hotlinking at the time. Surreal

http://www.easternus...ost__p__4841967

Wow nice.

[Srain]

Except in Politics apparently. To expand upon EPAC for a moment, that West Coast trough tends to extend south fairly soon in the Fall setting up unfavorable environments for development. Usually it clears the monsoon out of Arizona in September and sets the stage for recurvature events. EPAC storms were often referred to as "Cordonazo de San Francisco" (the Lash of St. Francis) in Mexico for the simple reason that they always seemed to hit around the feast day of St. Francis which is in October. Most remnant hits in AZ have occurred in September and October though Lester hit us in late August in 1992. By November, we start to get upper troughs diving south off the CA coast and closing off off the SoCA or Baja Coasts with the trough digging well down into the lower latitudes. This usually triggers what I call a Banana Express or moisture plume event (or atmospheric river) into the SW which can dump a lot of rain. The champion in this regard happened on November 11 1994 when a ULL closed off off the Baja spur triggering a moisture plume from the equator into AZ. Three to eight inches of rain fell in 24 hours in Cochise County and the wind fields aloft were so strong that TS force winds occurred. But there was no TS or even remnant involved. The last storm to landfall in 1994 was H. Rosa which was picked up by a trough over AZ and sent into TX as a TD with the remnants spreading very heavy rains into the Plains.

Steve

Don't let PR keep you a stranger. I can do without fire on the water like we had with Rosa...

http://www.fws.gov/southwest/es/contaminants/NRDAR/SiteInformation/Texas/SanJac.pdf

[Ed Lizard]

A week away from a 1000 mb TD in the East Pac. Looks like I can trace the GFS feature back.

[Srain]

From the morning EPAC TWD:

AT THE SURFACE...A 1010 MB AREA OF LOW PRES IS EMBEDDED WITHIN

THE ITCZ NEAR 05N91W. THE CLOUD FIELD SHOWS SOME CYCLONIC

TURNING AND EARLIER ASCAT PASSES INDICATED A BROAD CYCLONIC

CIRCULATION. CONVECTION ASSOCIATED WITH THIS LOW IS AS DESCRIBED

IN THE ITCZ SECTION ABOVE. COMPUTER MODELS SHOW THIS SYSTEM

PERSISTING OVER THIS REGION WHILE NOT MOVING MUCH DURING THE

NEXT SEVERAL DAYS. A WEAKER 1011 MB AREA OF LOW PRES IS NEAR

04N117W WITH CONVECTION AS DESCRIBED IN THE ITCZ SECTION ABOVE.

A TROUGH IS JUST N OF THIS LOW EXTENDING FROM 12N118W TO

07N115W. SCATTERED MODERATE CONVECTION WAS WITHIN 90 NM OF THE

TROUGH.

Edit to add:

Morning visible loops as well as mimic suggest a nice rotation becoming established.

[HurricaneJosh]

Except in Politics apparently. To expand upon EPAC for a moment, that West Coast trough tends to extend south fairly soon in the Fall setting up unfavorable environments for development. Usually it clears the monsoon out of Arizona in September and sets the stage for recurvature events. EPAC storms were often referred to as "Cordonazo de San Francisco" (the Lash of St. Francis) in Mexico for the simple reason that they always seemed to hit around the feast day of St. Francis which is in October. Most remnant hits in AZ have occurred in September and October though Lester hit us in late August in 1992. By November, we start to get upper troughs diving south off the CA coast and closing off off the SoCA or Baja Coasts with the trough digging well down into the lower latitudes. This usually triggers what I call a Banana Express or moisture plume event (or atmospheric river) into the SW which can dump a lot of rain. The champion in this regard happened on November 11 1994 when a ULL closed off off the Baja spur triggering a moisture plume from the equator into AZ. Three to eight inches of rain fell in 24 hours in Cochise County and the wind fields aloft were so strong that TS force winds occurred. But there was no TS or even remnant involved. The last storm to landfall in 1994 was H. Rosa which was picked up by a trough over AZ and sent into TX as a TD with the remnants spreading very heavy rains into the Plains.

Steve

Well, what a treat to see you stopping by!

Re: the bold part-- yep, that is my favorite part of the EPAC season. The vast majority of the intense (100-kt+) cyclone landfalls on this side happen in October.

P.S. That's a cool bit of history-- the thing about "Cordonazo de San Francisco".

[HurricaneJosh]

Omg, it's my first post of the year Re: an actual disturbance in our hemisphere. Woo hoo!

There's definitely a cyclonic turning to it-- but it looks a bit flimsy and, man, that is waaaaay deep down there. It's funny-- after looking at Aussie cyclones for five months, the stuff over on our side now looks weird to me-- like it's not turning the right way.

[Ed Lizard]

If the drought keeps going, an October EastPac hurricane may be our best friend here in Texas.

I'd like to spend more time in the Central US 3+ (Alaska, too) time zone forum, but only so much one can say about Sunny, warm and dry with a dry Pacific frontal passage every 5 days.

Anyhoo, our local forum professional met has done fairly well with the TPW animations in predicting which waves are likely to develop...

[HurricaneJosh]

To add a little to the topic of intense October landfalls...

As I've mentioned previously, October is the month for major-hurricane landfalls on Mexico's Pacific coast. As Steve alluded to (above), it's later in the season that the troughs start digging deeper and recurving cyclones back toward the mainland-- rather than letting them fish out.

Mexico's Pacific coast has had 10 Cat-3+ landfalls since 1949. Of those, 8-- yes 8!!-- happened in October.

Following are all Cat-3+ landfalls on Mexico's Pacific coast since 1949-- showing year, name, date, state, and intensity. Note that only Kiko 1989 and Lane 2006 were not in October:

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)

In terms of intensity... The Great Mexico Hurricane of 1959 is considered to be the strongest landfall in this region and the only Cat 5 on MX's Pacific coast. I'd like to see some contemporary reanalysis on this one-- to verify that it would still be estimated as a Cat 5 by modern standards. I'm frankly skeptical. Madeline 1976-- a devastating event-- is considered No. 2. Kenna 2002-- the inner core of which narrowly missed Puerto Vallarta-- is considered No. 3.

In terms of regions... Note that Sinaloa is kind of like MX's Florida: half the majors landfalled in that state.

Note: This post contains material from Eastern's EPAC thread last year. Yes, I recycled it.

[Ivanhater]

A PERSISTENT AREA OF DEEP CONVECTION IS ASSOCIATED WITH A WEAK

LOW PRES NEAR 04N91W. VIS SATELLITE IMAGERY SHOWS FAIR AMOUNT OF

LOW LEVEL CONVERGENCE INTO THE LOW AND EVIDENCE OF SOME CYCLONIC

TURNING IN THE ANIMATED IMAGERY. INTRUSION OF DRY MID-LEVEL AIR

FROM THE NORTH OVERNIGHT HAS HELPED SUPPRESS MUCH OF THE STRONG

CONVECTION FROM EARLIER THIS MORNING...BUT THE FACT THAT TSTMS

REMAIN PERSISTENT NEAR THE LOW IN SPITE OF SEVERAL INHIBITING

FACTORS INDICATES THIS OFF-SEASON AREA OF LOW PRESSURE MAY BEAR

WATCHING OVER THE NEXT COUPLE OF DAYS. GFS AND ECMWF MODELS KEEP

THE CIRCULATION VIABLE FOR SEVERAL DAYS ALTHOUGH ONLY AT 15-20 KT

BUT THIS IS THE FIRST SIGN OF LIFE FOR THE TROPICAL E PACIFIC SO

FAR IN 2011. EXPECT THE LOW TO DRIFT WNW THE NEXT 5-7 DAYS WITH

LITTLE CHANGE IN INTENSITY THROUGH THE WEEKEND.

http://www.nhc.noaa.gov/text/refresh/MI ... 0945.shtml

[HurricaneJosh]

Interesting.

[Ed Lizard]

Darn.

[HurricaneJosh]

Less than a month to go.

[k***]

in honor of us being less than a month away from the season, i present my EPAC haiku:

oh the fish parade

josh waits until october

stratocumulus.

[HurricaneJosh]

in honor of us being less than a month away from the season, i present my EPAC haiku:

oh the fish parade

josh waits until october

stratocumulus.

[Scorpion]

Who cares.. hopefully the EPAC is terrible again this year