More pre-season predictions of a very active Atlantic hurricane season
Hello again, it's Jeff Masters back again after a week away. Well, the past week was a wicked hot time to be in New England, where I was vacationing, and I certainly didn't expect to see 98° temperatures in Maine like I experienced! Fortunately, it's not hard to find cold water to plunge into in New England. Thankfully, the tropics were relatively quiet during my week away, and remain so today. There are no threat areas in the Atlantic to discuss at present, and none of the reliable computer models is forecasting tropical cyclone development over the next seven days. The NOGAPS model does show a strong tropical disturbance developing near the waters offshore of Nicaragua and Honduras this weekend, though. With not much to discuss in the present-day tropics, let's take a look at more pre-season predictions of the coming Atlantic hurricane season.
2010 Atlantic hurricane season forecast from Penn State
Dr. Michael Mann and graduate student Michael Kozar of Penn State University (PSU) issued their 2010 Atlantic hurricane season forecast on May 28. Their forecast utilizes a statistical model to predict storm counts, based on historical activity. Their model is predicting 19 to 28 named storms in the Atlantic, with a best estimate of 23 storms. The forecast assumes that record warm SSTs will continue in the Atlantic Main Development Region for hurricanes. Dr. Mann has issued two previous forecasts, in 2007 and 2009. The 2007 forecast was perfect--15 storms were predicted, and 15 storms occurred. The 2009 forecast called for 11.5 named storms, and 9 occurred (the 2009 forecast also contained the caveat that if a strong El Niño event occurred, only 9.5 named storms were expected; a strong El Niño did indeed occur.) So, the 2009 forecast also did well.
2010 Atlantic hurricane season forecast from the UK GloSea model
A major new player in the seasonal Atlantic hurricane season forecast game is here--the UK Met Office, which issued its first Atlantic hurricane season forecast in 2007. The UK Met Office is the United Kingdom's version of our National Weather Service. Their 2010 Atlantic hurricane season forecast calls for 20 named storms, with a 70% chance the number will range between 13 and 27. They predict an ACE index of 204, which is about double the average ACE index.
I have high hopes for the UK Met Office forecast, since it is based on a promising new method--running a dynamical computer model of the global atmosphere-ocean system. The CSU forecast from Phil Klotzbach is based on statistical patterns of hurricane activity observed from past years. These statistical techniques do not work very well when the atmosphere behaves in ways it has not behaved in the past. The UK Met Office forecast avoids this problem by using a global computer forecast model--the GloSea model (short for GLObal SEAsonal model). GloSea is based on the HadGEM3 model--one of the leading climate models used to formulate the influential UN Intergovernmental Panel on Climate Change (IPCC) report. GloSea subdivides the atmosphere into a 3-dimensional grid 0.86° in longitude, 0.56° in latitude (about 62 km), and up to 85 levels in the vertical. This atmospheric model is coupled to an ocean model of even higher resolution. The initial state of the atmosphere and ocean as of June 1, 2010 were fed into the model, and the mathematical equations governing the motions of the atmosphere and ocean were solved at each grid point every few minutes, progressing out in time until the end of November (yes, this takes a colossal amount of computer power!) It's well-known that slight errors in specifying the initial state of the atmosphere can cause large errors in the forecast. This "sensitivity to initial conditions" is taken into account by making many model runs, each with a slight variation in the starting conditions which reflect the uncertainty in the initial state. This generates an "ensemble" of forecasts and the final forecast is created by analyzing all the member forecasts of this ensemble. Forty-two ensemble members were generated for this year's UK Met Office forecast. The researchers counted how many tropical storms formed during the six months the model ran to arrive at their forecast of twenty named storms for the remainder of this hurricane season. Of course, the exact timing and location of these twenty storms are bound to differ from what the model predicts, since one cannot make accurate forecasts of this nature so far in advance.
The grid used by GloSea is fine enough to see hurricanes form, but is too coarse to properly handle important features of these storms. This lack of resolution results in the model not generating the right number of storms. This discrepancy is corrected by looking back at time for the years 1989-2002, and coming up with correction factors (i.e., "fudge" factors) that give a reasonable forecast.
The future of seasonal hurricane forecasts using global dynamical computer models is bright. Their first three forecasts have been good. Last year the Met Office forecast was for 6 named storms and an ACE index of 60. The actual number of storms was 9, and the ACE index was 53. Their 2008 forecast called for 15 named storms, and 15 were observed. Their 2007 forecast called for 10 named storms in July - November, and 13 formed. A group using the European Center for Medium Range Weather Forecasting (ECWMF) model is also experimenting with some promising techniques using that model. Models like the GloSea and ECMWF will only get better as increased computer power and better understanding of the atmosphere are incorporated, necessitating less use of "fudge" factors based on historical hurricane patterns. If human-caused climate change amplifies in coming decades, statistical seasonal hurricane forecasts like the CSU's may be limited in how much they can be improved, since the atmosphere may move into new patterns very unlike what we've seen in the past 100 years. It is my expectation that ten years from now, seasonal hurricane forecasts based on global computer models such as the UK Met Office's GloSea will regularly out-perform the statistical forecasts issued by CSU.
2010 Atlantic hurricane season forecast from Florida State University
Last year, another group using dynamical computer forecast models entered the seasonal hurricane prediction fray. A group at Florida State University led by Dr. Tim LaRow introduced a new model called COAPS, which is funded by a 5-year, $6.2 million grant from NOAA. This year, the COAPS model is calling for 17 named storms and 10 hurricanes. Last year's prediction by the COAPS model was for 8 named storms and 4 hurricanes, which was very close to the observed 9 named storms and 3 hurricanes.
Summary of 2010 Atlantic hurricane season forecasts
Here are the number of named storms, hurricanes, and intense hurricanes predicted by the various forecasters:
23 named storms: PSU statistical model
20 named storms: UKMET GloSea dynamical model
18.5 named storms, 11 hurricanes, 5 major hurricanes: NOAA hybrid statistical/dynamical model technique
18 named storms, 10 hurricanes, 5 intense hurricanes: CSU statistical model (Phil Klotzbach/Bill Gray)
17.7 named storms, 9.5 hurricanes, 4.4 intense hurricanes: Tropical Storm Risk (TSR), hybrid statistical/dynamical model technique
17 named storms, 10 hurricanes: FSU dynamical model
10 named storms, 6 hurricanes, 2 intense hurricanes: climatology
Only four hurricane seasons since 1851 have had as many as nineteen named storms, so 5 out of 6 of these pre-season forecasts are calling for a top-five busiest season in history. One thing is for sure, though--this year won't be able to compete with the Hurricane Season of 2005 for early season activity--that year already had five named storm by this point in the season, including two major hurricanes (Dennis and Emily.)
Tropical Storm Conson threatens the Philippines
Weather456 has an interesting post on why the Western Pacific typhoon season has been exceptionally inactive this year. It looks like we'll have out first typhoon of the Western Pacific season later today, since Tropical Storm Conson appears poised to undergo rapid intensification, and should strike the main Philippine island of Luzon as a Category 1 or 2 typhoon.
Next post
I'll have an update Wednesday.
Jeff Masters
Reader Comments
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Precisely!
I went back an looked at some historical season data, and also at cool phase PDO years which also occurred near Solar Minimums in the past, as far back as I could go. Since the PDO last changed phase (from cool to warm) in 1978 or so, most of the applicable storm season records predate the satellite era. What I saw though was, on average, only about 5-6 landfalling storms during these years, with most recuving through the Gulf of Mexico into the southern states, and only a couple threatening the east coast.
From this casual observation I draw two rough conclusions. First, the storms remain weaker, or fail to develop into tropical storms/hurricanes due to climatic and/or solar influences until reaching the seasonably warm waters of the Caribbean or Gulf of Mexico. There were still land-falling major hurricanes so this does not mean they remain weaker once reaching the Gulf. Second, being weaker in the Atlantic and Caribbean, they have a harder time fighting the Bermuda High, or due to climatic influences, the BH sets up farther to the west, closer to the Eastern US seaboard.
I did not, in any year with a cool PDO and Solar Minimum, find any season as active as what this year has been predicted to be. I'm arguing that a combination of developing La Nina, cool Pacific Decadal Oscillation phase, and the Solar Minimum will all combine to prevent the "season o' doom" which was predicted.
Anyone else with thoughts about this. I cross referenced Wikipedia storm season data with Solar Min/Max charts, and finally looked at the roughly 30 year PDO cycle to get in the ballpark. It ain't exactly a scientific method but it's what I had available.
I'd say my "guesstimate" is somewhere less than 12 named storms, total, with 5-8 landfalling as hurricanes. At least three hurricanes making landfall will be major and will strike the US.
LOL
Hard to put the experience into words. I visited a Fragipani at dusk. In the darkness the white flowers glowed while the thick scent enveloped the entire tree. It's one of those moments where you wish life had a pause-button.
What did he/she do? I only started coming on here last year. Seems like the majority on here don't want him/her here....just curious.
I've been wondering the same thing!
Of course, if he starts insulting people then I support the reporting him, but if not, eh... what the heck!
I'm tired of this happening everyday. *sigh*
Also, looks quiet in the Atlantic, I just hope it stays that way for a loooooong time, sorry I know some will loose their sanity, but I'll take quiet conditions any day. =)
I have been here for 3 years, mostly lurking though, and have still not figured that out! lol.
I like the new Avatar btw...
yup
His named storms prediction are pretty low all things considered. His prediction of upwards of 75% of the 12 making landfall are pretty high percentage wise. You would need twice the number of storms to even come close to that percentage, although 5 landfalls could be possible but not with only 12 named storms.
BTW, are u near / from the location in ur handle? That sounds like US NW somewhere...
I don't know what software they use here, but at a forum where I am a mod I use the IP ban fairly frequently. If the code is well-written, you can ban anything from a specific address to an entire block of addresses. Of course, it is not terribly difficult for the determined to spoof an IP address.
you most ues storm2k
47N 91W is somewhere in North-Central Wisconsin...
You must not have seen the ugly side of JFV. He's not a cute innocent kid on here that just happens to be annoying. He's a troll.
Yeah, my handle brings you pretty close to my home coordinates. Unfortunately, tropical trees wouldn't survive very long on the shores of Lake Superior. My experience with Fragipani (and other tropical trees) is centered around two years near 12 degrees S and 27 degrees E. What I would give to be able to experience that landscape again!
No, its not a weather related forum.
oh
Well, we have already seen more activity than this year did! I'm curious though, on how many storms went undetected that year.
Pretty much anything east of about 40 degrees (give or take) would have been missed before satellite. Same is true of minicanes like Marco.
I also don't think the database has any depressions (that didn't subsequently become tropical storms or hurricanes) that far back. Therefore, there may have been more "known" tropical cyclones.
That's a lot closer to where they actually come from... If u can't get back there, u can find frangipani (transported, of course lol) pretty much throughout the Bahamas and Caribbean. I'll bet there are even some in S FL, though I don't recall actually seeing any growing there.
The biggest single breakthrough application for weather forecasting, including the tropics, was the sattelite starting in the 60's....We will never know the true extent of past h-seasons before the modern era unless land fall occured in "recorded" populated areas.
I have 18 on my list...ignore that is (I've given up the whole JVF is back thing)...he comes back in, I detect it's him, I ignore him and I move on
LOL!
you got mail
430 PM CDT TUE JUL 13 2010
.SYNOPSIS...THE NORTHERN PORTION OF A TROPICAL WAVE WILL MOVE
ACROSS THE BAY OF CAMPECHE TONIGHT. WEAK RIDGE FROM S FLORIDA TO
23N93W WILL SHIFT N TO ALONG 28N WED THROUGH THU AND TO JUST N
OF THE GULF FRI AND SAT AS A TROUGH MOVES FROM E TO W ACROSS
GULF THU THROUGH SAT. THE RIDGE WILL BUILD AGAIN FROM E TO W
ACROSS THE GULF WATERS BY SUN.
SYNOPSIS FOR CARIBBEAN SEA AND TROPICAL N ATLC FROM 07N TO 22N
BETWEEN 55W AND 65W
530 PM EDT TUE JUL 13 2010
.SYNOPSIS...A TROPICAL WAVE ALONG 55W WILL MOVE ACROSS THE
REMAINDER OF THE TROPICAL N ATLC THIS EVENING THROUGH THU BEFORE
ENTERING THE EASTERN CARIBBEAN SEA THU EVENING. THE WAVE WILL
THEN MOVING THROUGH THE REMAINDER OF THE EASTERN CARIBBEAN
OVERNIGHT THU INTO FRI...AND SHOULD REACH NEAR 70W BY SAT.
ANOTHER TROPICAL WAVE IS EXPECTED TO APPROACH THE FAR EASTERN
TROPICAL N ATLC WATERS LATE SAT REACHING THE E CARIBBEAN LATE
SUN.
5pm EDT
Joint Typhoon Warning Center Advisory #10
*NEW* Graphics Update
DISCUSSION...
THE AREA OF CLOUDINESS AND MOISTURE ACROSS THE CENTRAL AND
NORTHERN BAHAMAS CONTINUES TO MOVE SLOWLY WESTWARD. THIS IS
CONSISTENT WITH THE LATEST GUIDANCE...INDICATING THAT THE LEADING
EDGE OF THE LOW LEVEL MOISTURE COULD APPROACH THE ATLANTIC COAST OF THE
SOUTH FLORIDA PENINSULA AROUND 12Z WEDNESDAY. THE LATEST GUIDANCE
ALSO INDICATED MORE NUMEROUS SHOWER AND SCATTERED THUNDERSTORM
ACTIVITY BY WEDNESDAY AFTERNOON WHICH SEEMED REASONABLE WITH THE
INCREASE IN MOISTURE ACROSS THE REGION...WITH A GENERAL INCREASE
IN POPS ACROSS THE PENINSULA FOR WEDNESDAY AFTERNOON. BY THURSDAY AND
FRIDAY SOUTHEASTERLY LOW LEVEL FLOW WILL CONTINUE TO BRING
ADDITIONAL MOISTURE ACROSS THE AREA WITH SCATTERED SHOWERS AND A
CHANCE OF THUNDERSTORMS...MAINLY IN THE AFTERNOON.
Viewing: 1951 - 2001
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