EPAC Tropical Action 2012

[U_Thant]

Q. Did you hear the one about Josh laughing this morning after he saw the eastward trend in the ECM?

A. Yeah, he went BAAAAAJAJAJAJAJAJAJA.

*rimshot*

I'll be here all week folks.

[HurricaneJosh]

Q. Did you hear the one about Josh laughing this morning after he saw the eastward trend in the ECM?

A. Yeah, he went BAAAAAJAJAJAJAJAJAJA.

*rimshot*

I'll be here all week folks.

[GaWx]

Climatology for weak, warm, west-based ENSO events show a significant reduction in the amount of landfalling Mexican cyclones in late September and October...and as the atmosphere will likely only become more like that of El Niño by mid-October (see my post in the Atlantic thread)...I think everyone can safely stick a fork in the EPAC, which--with a few exceptions like Kenna 2002, Marty 2003, Norbert 2008, and Jova 2011--has generally been extremely crappy over the past decade, both in terms of intensity and, even more noticeably, in terms of overall activity relative to those of those of the 1970s and 1990s. Global TC activity has been particularly low since 2005...but I cannot really discuss why because it would lead into a discussion about climate change.

I think you're off on your El Nino climo. To the contrary, El Nino (Sep.'s and Oct.'s, combined,) has been the most active of the three ENSO phases since 1949 in terms of major hits on the W. coast of Mexico. Out of the 9

major Sep./Oct. hits, five (56%) were during El Nino! Three were during La Nina and one was during neutral. Considering that each accounts for about 1/3 of the seasons, I'd say that El Nino has more than

held its own. Even more impressive, 3 of the 4 cat. 4+ hits were during El Nino! The other was during neutral. So, there have been three cat. 4+ hits during El Nino and NONE during La Nina since 1949. Also, the only season with two major Oct. W. Mexican coast hits was El Nino (a weak one fwiw)!

Based on the stat that 4 of the 8 Oct. major W. Mexican hits were during the 19 El Nino seasons since 1949, I'm giving it a respectable one in four to one in five chance of occurring in Oct. of 2012. Had we been in either neutral negative or La Nina, I would have gone with something no higher than about one in eight.

[Ground Scouring]

Larry,

You may have misunderstood me. I meant that, because the current Niño is developing no earlier than mid-October--and since the Niña-like atmosphere is not likely to change significantly before then--the chance of a major EPAC landfall is lower this year than in other, more typical Niño seasons. Also, the fact that this Niño will be weak at most and slow to develop tends to reduce the prospects of a major landfall due to 1) late development, as most majors occur before in the first half of October (Mexico 1959 and Kenna 2002 being noteworthy late-comers); and 2) the fact that the majority of the October strikes occurred when the Niño was either moderate or strong OR had a stronger atmospheric signal. (This is what I really meant to Josh as well.)

[HurricaneJosh]

Larry,

You may have misunderstood me. I meant that, because the current Niño is developing no earlier than mid-October--and since the Niña-like atmosphere is not likely to change significantly before then--the chance of a major EPAC landfall is lower this year than in other, more typical Niño seasons. Also, the fact that this Niño will be weak at most and slow to develop tends to reduce the prospects of a major landfall due to 1) late development, as most majors occur before in the first half of October (Mexico 1959 and Kenna 2002 being noteworthy late-comers); and 2) the fact that the majority of the October strikes occurred when the Niño was either moderate or strong OR had a stronger atmospheric signal. (This is what I really meant to Josh as well.)

But again, 8 of the 10 major strikes in this basin occurred in October, so in any year, I'm going to bet on October over other months.

[GaWx]

Larry,

You may have misunderstood me. I meant that, because the current Niño is developing no earlier than mid-October--and since the Niña-like atmosphere is not likely to change significantly before then--the chance of a major EPAC landfall is lower this year than in other, more typical Niño seasons. Also, the fact that this Niño will be weak at most and slow to develop tends to reduce the prospects of a major landfall due to 1) late development, as most majors occur before in the first half of October (Mexico 1959 and Kenna 2002 being noteworthy late-comers); and 2) the fact that the majority of the October strikes occurred when the Niño was either moderate or strong OR had a stronger atmospheric signal. (This is what I really meant to Josh as well.)

Snowflake,

Thanks for the clarification. Nice discussion. I'll counter your two points.

1) Of the eight major Oct. W. Mexico hits, two hit 10/1-10, two hit 10/11-20, and FOUR hit 10/21-31. So, if anything, the heavier weighting is late rather than early in Oct.

2) Based on the fall/winter ONI peak, which is what I use for Nino strength, weak Nino was well represented by 1976 with the two major Oct. hits on the W. coast of Mexico. Also, 2006 was only barely moderate. The five El Nino hits consisted of two weak, two moderate, and only one strong. Finally, the three strongest El Nino seasons, 1972, 1982, and 1997, had no hits. When considering all of this, I don't see the overall evidence supporting stronger El Nino over weaker. I'd say that the overall data suggests that the weak to moderate Nino state per ONI out of all ENSO states is what you'd want if you wanted the best shot at a late season major W. Mexico hit.

[David Reimer]

12Z SHIPS Rapid Intensification Index. Very impressive!

Prob of RI for 25 kt RI threshold= 80% is 6.8 times the sample mean(11.7%)

Prob of RI for 30 kt RI threshold= 75% is 9.5 times the sample mean( 7.9%)

Prob of RI for 35 kt RI threshold= 66% is 12.0 times the sample mean( 5.4%)

Prob of RI for 40 kt RI threshold= 66% is 20.4 times the sample mean( 3.9%)

[GaWx]

12Z SHIPS Rapid Intensification Index. Very impressive!

Prob of RI for 25 kt RI threshold= 80% is 6.8 times the sample mean(11.7%)

Prob of RI for 30 kt RI threshold= 75% is 9.5 times the sample mean( 7.9%)

Prob of RI for 35 kt RI threshold= 66% is 12.0 times the sample mean( 5.4%)

Prob of RI for 40 kt RI threshold= 66% is 20.4 times the sample mean( 3.9%)

I know that in the Atlantic that SHIPS tends to be biased too strong. What about in the EPAC? Do you have a good feel for it?

[GaWx]

2) Based on the fall/winter ONI peak, which is what I use for Nino strength, weak Nino was well represented by 1976 with the two major Oct. hits on Baja. Also, 2006 was only barely moderate. The five El Nino hits consisted of two weak, two moderate, and only one strong. Finally, the three strongest El Nino seasons, 1972, 1982, and 1997, had no hits. When considering all of this, I don't see the overall evidence supporting stronger El Nino over weaker. I'd say that the overall data suggests that the weak to moderate Nino state per ONI out of all ENSO states is what you'd want if you wanted the best shot at a late season major Baja hit.

Further to the strength of El Nino correlated most with a major W. Mexico hit:

Fwiw, I decided to check the monthly SOI indices when the ten majors hit the west coast of Mexico because the SOI is a pretty good representation of what the atmosphere is currently doing ENSOwise:

10/1957: -0.3

10/1959: +4.7

10/1967: -0.3

10/1975: +18.6

10/1976: +3.5 (two hits)

10/1983: +4.7

8/1989: -5.6

10/2002: -7.6

9/2006: -4.6

A typical stronger (say moderate or stronger) El Nino late summer or fall SOI month is in the -10's or

-20's. Even some weak El Nino late summer/fall months are in the -10's. Notice that the lowest SOI here was only down at -7.6. Even the one strong El Nino season hit (10/1957) was during a month with an SOI that was barely negative (-0.3). The most favored range seems to be ~+5 to -8...i.e., fairly neutral SOIwise. Looking at just El Nino hits, the SOI's were as follows: -0.3, +3.5, +3.5, -7.6, and -4.6...i.e., all fairly neutral. Sep. 2012 MTD is at ~+2.7. Aug. 2012 was at -6.2 and July 2012 was at +0.1. The outlook for the next ten days based on the Euro model is for no big extremes for the most part. So, Sep. as a whole looks to finish at ~+1 to +4 while Oct. starts faily close to 0 overall...say -5 to +5. As long as we can keep the weak El Nino going ONIwise (which I fully expect) despite the recent/current Nino 3.4 cooling and not have a very negative SOI getting established by mid- Oct., I'd say that the current combo of ONI SST's and SOI's is nearly ideal for this season having about as good a shot at a major W. Mexico hit as any season per ENSO climo. I still have the chance at well under 50% as I'm going about 1 in 4 to 1 in 5 right now. However, going 1 in 4 is about as high as I'd go for any season (without an actual major storm already threatening the W. coast of Mexico) being that the longterm odds are only about 1 in 6.

[HurricaneJosh]

Just to clarify... The "Baja" is that long, skinny Peninsula below California-- not the entire W coast of MX-- and there are only two known instances of a major hitting the Baja Peninsula: Olivia 1967 and Kiko 1989.

The Baja Peninsula is kind of like NC-- it gets a lot of action because it sticks out, but because it's further N, it's almost always Cat 1s and 2s-- not the really heavy, red-meat cyclones.

[HurricaneJosh]

However, going 1 in 4 is about as high as I'd go for any season (without an actual major storm already threatening Baja) being that the longterm odds are only about 1 in 6.

Assuming you mean "W coast of MX", this makes sense to me. On any given year, the chance of a major landfall isn't that high, but El Nino is going to help a little.

[GaWx]

Just to clarify... The "Baja" is that long, skinny Peninsula below California-- not the entire W coast of MX-- and there are only two known instances of a major hitting that Peninsula (Olivia 1967 and Kiko 1989).

Josh,

Ooopps. My bad! Thanks for posting this. Yes, I know where Baja is located. However, for some reason, I was thinking your list of ten was for just the major Baja hits. Oy. Regardless, this doesn't change anything as far as my feeling that we're in about as good a shape as we could be in climowise for the best shot at a major W. coast of Mexican hit between now and ~10/31. I need to go back and change "Baja" to "W. coast of Mexico".

Edit: changes made. All references to "Baja" have been changed to "W. coast of Mexico".

[HurricaneJosh]

Josh,

Ooopps. My bad! Thanks for posting this. Yes, I know where Baja is located. However, for some reason, I was thinking your list of ten was for just the major Baja hits. Oy. Regardless, this doesn't change anything as far as my feeling that we're in about as good a shape as we could be in for the best shot at a major W. coast of Mexican hit between now and ~10/31. I need to go back and change "Baja" to "W. coast of Mexico".

No biggie-- I knew what you meant.

As you can see, the W coast of MX just doesn't get hit by majors that often. Anyhoo, thanks for these interesting climo-- it's slightly encouraging.

[Ed Lizard]

Miriam is now a hurricane.

NHC forecast is this close to becoming a major before becoming terminally ill.

[HurricaneJosh]

The 00Z Euro actually recurves Miriam into the Baja-- rather than stalling itout offshore-- but the run really weakens the cyclone en route, so that it comes ashore as crap.

[HurricaneJosh]

The 2 am PDT advisory is out. Miriam has continued to rapidly strengthen-- now up to 90 kt and expected to become a major later today. This aside, the forecas continues to trend right and stronger, so that what we previously expected to be a fish is now looking like a possible TS impact for the Baja Peninusla. I'm gonna continue to watch this.

[Ed Lizard]

105 knots with a hawt vis presentation.

( i-Cyclone terminology).

Not giving up in the extended range on mid level moisture over my neighborhood.

[HurricaneJosh]

It is hawt.

[snowmanwx]

Some observations from Miriam (times are UTC, wind speeds [vels and velr] in km/hr [1 km/hr = 0.54 knot], precipitation [prec] in mm):

Estación: I. CLARION, COL

Operada por: SEMAR

Longitud: 114°44'03" Latitud: 18°20'18" Altitud:

[/font]
[font=courier new,courier,monospace]DD/MM/AAAA HH:MM    DIRS    DIRR	  VELS	  VELR	 TEMP     HR		PB    PREC RAD-SOL
24/09/2012 16:30       3	 358	 47.70	 68.70	 27.3     89	1004.3	 0.0
24/09/2012 17:00	 258	  20	 47.50	 68.50	 27.4     89	1003.9	 0.0
24/09/2012 17:30	 274      11	 46.10	 68.50	 27.3     90	1003.7	 0.0
24/09/2012 18:00	 305       2	 47.50	 75.40	 27.3	 90	1002.9	 0.0
24/09/2012 18:30	 358       7	 50.20	 81.40	 27.2	 90	1002.2	 0.0
24/09/2012 19:00	 278       3	 56.20	 87.70	 26.1	 92	1001.8	 0.8
24/09/2012 19:30	 309	   4	 62.50	108.70	 26.0	 93	1000.6	 0.3
24/09/2012 20:00		       0          	 88.30	 26.1	 93	1000.0	 0.0
24/09/2012 20:30			 345         	  85.40	 26.0	 91	 999.2	 0.8
24/09/2012 21:00	 27      358     54.60	 97.70	 26.1	 91	 998.7	 0.0
24/09/2012 21:30	 0        15     60.30	 87.80	 26.2	 88	 997.6	 0.0
24/09/2012 22:00	 359       3     64.00	 91.40	 25.7	 92	 997.0	 1.0
24/09/2012 22:30		       9               75.30	 25.3	 92	 996.5	 1.0
24/09/2012 23:00	 343	 344	 64.50	 93.30	 25.3	 93	 995.7	 1.0
24/09/2012 23:30	 350	 352	 65.50	 98.00	 25.6	 90	 995.1	 1.0
25/09/2012 00:00	 320	 349	 73.30	107.30	 25.1	 92	 994.2	 1.8
25/09/2012 00:30	 320	 334	 77.50	107.40	 24.8	 95	 993.4	 2.3
25/09/2012 01:00	 344	 352	 78.30	111.20	 25.2	 95	 992.7	 1.0
25/09/2012 01:30	 345	 334	 86.40	124.60	 24.9	 98	 991.8	 2.8
25/09/2012 02:00	 334	 358	 74.30	106.70	 24.9	 99	 991.6	 2.3
25/09/2012 02:30	 339	 342	 87.40	123.10	 25.2	 97	 990.3	 0.3
25/09/2012 03:00			 337			  119.00	 25.1	 96	 989.1	 4.3
25/09/2012 03:30	 348	 336	 90.90	148.40	 25.0    100	 987.9	 1.0
25/09/2012 04:00	 346	 356	 97.60	143.10	 25.0    100	 987.3	 2.0
25/09/2012 04:30	   1	 358	108.60	166.50	 24.9    100	 984.8	 2.8
25/09/2012 05:00				              154.20	 25.0    100	 984.2	 0.8
25/09/2012 05:30	           8 	         164.40	 24.9	 98	 983.2	 1.3
25/09/2012 06:00	 346	 348	106.50	143.30	 24.7	 99	 981.9	 2.0
25/09/2012 06:30	 320	 347	102.40	146.20	 24.6	 99	 981.2	 2.3
25/09/2012 07:00	 342	 348	102.00	133.50	 24.5    100	 980.3	 2.0
25/09/2012 07:30	 347	 351	 89.00	126.10	 24.5    100	 978.9	 0.5
25/09/2012 08:00	 343	 333	 75.30	107.90	 24.6	 99	 976.8	 0.0
25/09/2012 08:30	 309	 303	 39.00	 59.80	 24.8	 98	 977.7	 0.0
25/09/2012 09:00	 313	 312	 41.90	 63.10	 24.6	 98	 976.2	 0.0
25/09/2012 09:30	 314	 323	 53.70	 92.00	 24.6	 97	 975.2	 0.0
25/09/2012 10:00	 322	 323	 61.30	 88.70	 25.0	 96	 973.7	 0.0
25/09/2012 10:30	 289	 290	 46.40	 65.10	 24.8	 97	 976.5	 0.0
25/09/2012 11:00	 276	 300	 40.30	 68.70	 24.4	 97	 976.3	 0.0
25/09/2012 11:30	 277	 269	 51.60	 91.80	 24.4	 97	 977.0	 0.0
25/09/2012 12:00	 261	 253	 74.30	100.10	 24.3	 97	 976.2	 0.5
25/09/2012 12:30	 265	 258	 71.50	 96.70	 24.2	 98	 976.8	 1.3
25/09/2012 13:00	 270	 265	 80.60	115.10	 24.2	 97	 976.5	 0.3
25/09/2012 13:30	 266	 256	 75.60	 96.10	 24.1	 98	 976.7	 0.3
25/09/2012 14:00	 268	 257	 81.80	120.00	 24.1	 98	 977.5	 0.0
25/09/2012 14:30	 267	 264	 93.70	126.30	 24.1	 99	 979.2	 0.3
25/09/2012 15:00	 261	 266	 87.20	118.30	 24.2	 99	 980.1	 0.8
25/09/2012 15:30	 260	 271	 89.20	126.80	 24.4	 97	 981.6	 1.0[/font]
[font=courier new,courier,monospace]

[Ed Lizard]

Miriam ate the salmon mousse.

[Srain]

[HurricaneJosh]

Another fish in the making-- or, if it does come ashore, it'll be far N and weak. I'm cool with that. I don't want to chase a Norman-- it's just not a cool name.

[aslkahuna]

As an aside, the fishy Miriam of 1988 came to the EPAC courtesy of ATL hurricane Joan the remnants of which made the crossing through Guatemala and redeveloped.

Steve

[NYCSuburbs]

I don't remember the last time I saw an East Pacific tropical cyclone form this far northeast... storms have formed not far to the south of the Gulf of California in recent years but not almost within the gulf.

[wxmx]

I don't remember the last time I saw an East Pacific tropical cyclone form this far northeast... storms have formed not far to the south of the Gulf of California in recent years but not almost within the gulf.

Yep, you're right..cyclogenesis north of 22.5N is rare...and unheard of east of 135W ... closest to where Norman popped up is Kiko '89

[HurricaneJosh]

I'm glad the name Norman was wasted-- not into it, didn't want to chase it.

[PSUBlizzicane2007]

I'm glad the name Norman was wasted-- not into it, didn't want to chase it.

Oh you know how much you love landfalling 35 KT tropical storms.

[HurricaneJosh]

Oh you know how much you love landfalling 35 KT tropical storms.

Secret passions.

[aslkahuna]

BTW Josh, you're right-Norman storms in the past have pretty much been wimpy storms in EPAC. Some names have it some don't- Ivan was BIG in WPAC in 1997 and was retired after his first time out in the ATL, Katrina was significant in 1967 in EPAC and we all know what happened in her first ATL appearance. Rita and Wilma were big WPAC names and made the hit parade in the ATL. Irma is another big WPAC name due to show in the ATL.

Steve

[Ground Scouring]

BTW Josh, you're right-Norman storms in the past have pretty much been wimpy storms in EPAC. Some names have it some don't- Ivan was BIG in WPAC in 1997 and was retired after his first time out in the ATL, Katrina was significant in 1967 in EPAC and we all know what happened in her first ATL appearance. Rita and Wilma were big WPAC names and made the hit parade in the ATL. Irma is another big WPAC name due to show in the ATL.

Steve

Actually, I believe Ivan 1980 was a near-major hurricane in the Atlantic--and was very similar in formation and location to Michael this year--and so was Ivan 1998, though both were fishy tropical cyclones. Katrina also made her debut in 1981 in the Atlantic basin and struck Cuba as a minimal hurricane, though she did not make another appearance until 2005.