Active 2009 hurricane season predicted by Colorado State scientists

By: Dr. Jeff Masters , 4:20 PM GMT on December 10, 2008

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It's going to be a moderately more active than average Atlantic hurricane season in 2009, according to the latest seasonal forecast issued by Dr. Bill Gray and Phil Klotzbach of Colorado State University (CSU) today. The CSU team is calling for 14 named storms, 7 hurricanes, 3 intense hurricanes, and an ACE index 30% above average (Accumulated Cyclone Energy (ACE) is a measure of the total destructive power of a hurricane season, based on the number of days strong winds are observed). An average season has 10 named storms, 6 hurricanes, and 2 intense hurricanes. The CSU forecast calls for a 63% chance of a major hurricane hitting the U.S., which is 11% above average. The odds for a major East Coast hurricane are put at 39% (a 31% chance is average), and odds for the Gulf Coast are put at 38% (30% chance is average). The CSU team's prediction of an above average hurricane season hinges on two main factors:

1) An El Niño event is not expected in 2009. The current pressure pattern in the Northeast Pacific is one frequently associated with the development of a La Niña event. A number of the computer models used to forecast El Niño are now calling for development of a La Niña event in 2009. Lack of an El Niño event in 2009 will lead to average to below average values of wind shear over the Atlantic, enhancing hurricane activity.

2) Sea Surface Temperatures (SSTs) in the North Atlantic have been anomalously warm in October and November. This implies we are still in the active phase of the Atlantic Multidecadal Oscillation (AMO), the active period of hurricane activity that began in 1995.


Figure 1. Accuracy of long-range forecasts of Atlantic hurricane season activity performed by Bill Gray and Phil Klotzbach of Colorado State University (colored squares) and TSR (colored lines). The skill is measured by the Mean Square Skill Score (MSSS), which looks at the error and squares it, then compares the percent improvement the forecast has over a climatological forecast of 10 named storms, 6 hurricanes, and 2 intense hurricanes. TS=Tropical Storms, H=Hurricanes, IH=Intense Hurricanes, ACE=Accumulated Cyclone Energy, NTC=Net Tropical Cyclone Activity. Image credit: TSR.

How good are these December hurricane season forecasts?
Keep in mind that these December forecasts are a research project, and as yet have shown no skill in predicting the activity of upcoming hurricane seasons. They make this clear in the introduction to the December forecast, stating, "our real-time forecasts issued in early December from 1992-2007 did not show skill in real time". The CSU team talks extensively about their "hindcast" skill with these December forecasts, which means they can successfully predict the behavior of past hurricane seasons using their methodology. In their words, "It is only through hindcast skill that one can demonstrate that seasonal forecast skill is possible. This is a valid methodology provided that the atmosphere continues to behave in the future as it has in the past." The problem is that the atmosphere often does not continue to behave in the future as it has in the past, and a technique that is successful in a hindcast will often fail in a forecast. In their 2007 December forecast, they showed that the correlation coefficient (r squared), a standard mathematical measure of skill, was near zero for their real-time December forecasts between 1992-2007. They made a successful December 2007 forecast which was not included in that analysis, and their December skill is probably slightly positive now.

Another way to measure skill is using the Mean Square Skill Score (MSSS), which looks at the forecast error and squares it, then compares the percent improvement the forecast has over a climatological forecast of 10 named storms, 6 hurricanes, and 2 intense hurricanes (Figure 1). The skill of the December forecasts issued by both CSU and Tropical Storm Risk, Inc. (TSR) have averaged near zero since 1992. Not surprisingly, the forecasts get better the closer they get to hurricane season. The TSR forecasts show more skill than the CSU forecasts, but it is unclear how much of this superiority is due to the fact that TSR issues forecasts of fractional storms (for example, TSR may forecast 14.7 named storms, while CSU uses only whole numbers like 14 or 15). TSR does an excellent job communicating their seasonal forecast skill. Each forecast is accompanied by a "Forecast Skill at this Lead" number, and they clearly define this quantity as "Percentage Improvement in Mean Square Error over Running 10-year Prior Climate Norm from Replicated Real Time Forecasts 1987-2006."

The June and August forecasts from CSU, TSR, and NOAA show some modest skill, and are valuable tools for insurance companies and emergency planners to help estimate their risks. The key problem with forecasts done in April or earlier is that the El Niño/La Niña atmospheric cycle that can dominate the activity of an Atlantic hurricane season is generally not predictable more than 3-6 months in advance. For example, none of the El Niño forecast models foresaw the September 2006 El Niño event until May of 2006. Until we can forecast the evolution of El Niño more than six months in advance, December forecasts of Atlantic hurricane activity are merely interesting mental exercises that don't deserve the media attention they get. There is hope for the December forecasts, since Klotzbach and Gray (2004) showed that their statistical scheme could make a skillful forecast in December, when applied to 50 years of historical data. However, these "hindcasts" are much easier to make than a real-time forecast. For example, before 1995, it was observed that high rainfall in the Sahel region of Africa was correlated with increased Atlantic hurricane activity. This correlation was used as part of the CSU forecast scheme. However, when the current active hurricane period began in 1995, the correlation stopped working. Drought conditions occurred in the Sahel, but Atlantic hurricane activity showed a major increase. The CSU team was forced to drop African rainfall as a predictor of Atlantic hurricane activity.

References
Klotzbach, P.J., and W.M. Gray, "Updated 6-11 Month Prediction of Atlantic Basin Seasonal Hurricane Activity," Weather and Forecasting 19, Issue 5, October 2004, pp. 917-934.

Jeff Masters

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121. IKE
Terribly windy outside...frontal passage just happened....down to 57 degrees.
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Quoting sullivanweather:


Well, that would be acting in an efficient manner, which, as we all know, this country just prides itself in.


LOL!!!!! if only this country actually walks the walk instead of talk the talk most of the time

maybe things could change for the better.... hopefully.... if our govt makes a smart move and opens up its mind to the possibilities and actually follows through with it.
Member Since: August 14, 2008 Posts: 0 Comments: 658
Quoting Hurricane4Lex:
can anyone explain why noone builds underground powerlines in Hurricane and Winter weather prone areas?????

it would save people alot of trouble like it did for me during 04 in Florida and Ike in texas


Well, that would be acting in an efficient manner, which, as we all know, this country just prides itself in.
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can anyone explain why noone builds underground powerlines in Hurricane and Winter weather prone areas?????

it would save people alot of trouble like it did for me during 04 in Florida and Ike in texas
Member Since: August 14, 2008 Posts: 0 Comments: 658
I'm usually not one to advertise my blog but I feel sometimes, during certain situations, it is necessary.

Severe Nor'easter to pound the Northeast

AN EXTREMELY DANGEROUS, LIFE-THREATENING SITUATION IS DEVELOPING OVER THE INTERIOR OF THE NORTHEAST. RESIDENTS HOULD PREPARE FOR A DEVASTATING ICE STORM THAT WILL BRING DOWN NUMEROUS TREES AND POWER LINES. SOME AREAS COULD BE OUT OF POWER FOR SEVERAL DAYS AS UTILITY CREWS STRUGGLE TO GET A FOOT HOLD ON THE SITUATION. ANYONE IN THE AREAS EXPECTED TO RECEIVE HEAVY ICE ACCUMULATIONS SHOULD TAKE THE NECESSARY STEPS TO ENSURE THEIR SAFETY. TRAVEL IS HIGHLY DISCOURAGED THURSDAY AFTERNON THROUGH FRIDAY MORNING AS IT WILL BE VERY DIFFICULT, IF NOT IMPOSSIBLE. A VERY COLD AIRMASS WILL FOLLOW THE STORM LASTING INTO SATURDAY. TEMPERATURES BOTH FRIDAY AND SATURDAY NIGHTS ARE EXPECTED TO DROP INTO THE TEENS AND SINGLE DIGITS IN THE AFFECTED AREAS WHICH MAY PRESENT LIFE-THREATENING CONDITIONS FOR THOSE WHO RELY ON ELECTRICTY FOR HEATING PURPOSES.

I heed all living in the Northeast to take this winter storm very seriously!
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Bad weather coming to the bay area.
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Quoting AnthonyJKenn:
And to Joanie....depending on which part of SW LA you are in, you might get some wintry fun. Anyone north and west of a Lake Charles to Opelousas to Baton Rouge line is more likely to get some snow later this morning; everywhere else, more like cold rain with possibly a flurry and sleet pellet mixed in.

On the other hand, if it does get a couple of degrees colder than expected later on across the region, then the whole region could get a nice dusting...and we may even see some 1 inch accumulations especially in the northern parishes around Alex and Bunkie and points eastward. Even the coast might get some flurries if that holds up.


Anthony


I am in Calcasieu Parish in DeQuincy...I would like to see snow down here!!!!!
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Quoting NorthxCakalaky:
Winter Storm Warning for parts of Louisiana.(!Up to half a foot!) 3-5inches

Also, to note just looking I glanced there was a EF1 tornado touchdown.

Snow is expected from Texas to Alabama.



Actually, the Winter Storm Warnings that I see posted on the WU page are for central Mississippi, NOT Louisiana. Most areas of Louisiana is under a Winter Weather Advisory for possible snow/sleet mix and a low threat of accumulation, but nothing like what is forecasted for the Jackson area.


Anthony
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And to Joanie....depending on which part of SW LA you are in, you might get some wintry fun. Anyone north and west of a Lake Charles to Opelousas to Baton Rouge line is more likely to get some snow later this morning; everywhere else, more like cold rain with possibly a flurry and sleet pellet mixed in.

On the other hand, if it does get a couple of degrees colder than expected later on across the region, then the whole region could get a nice dusting...and we may even see some 1 inch accumulations especially in the northern parishes around Alex and Bunkie and points eastward. Even the coast might get some flurries if that holds up.


Anthony
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Three to five inches?!?! Where are you getting that info from??

I live in South Central Louisiana, and all the info I see as of right now list no more than at best one-half an inch of snow, if that. If it even reaches the ground.

Right now, we are getting just a cold rainy drizzle...but I'm figuring that later tonight into sunrise we may get some frozen stuff..if we're lucky. Most times, it all misses us to the north...but we might get lucky.


Anthony
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Quoting NorthxCakalaky:
Winter Storm Warning for parts of Louisiana.(!Up to half a foot!) 3-5inches

Also, to note just looking I glanced there was a EF1 tornado touchdown.

Snow is expected from Texas to Alabama.



Where in Louisiana?? And when was the EF tornado touchdown???
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Winter Storm Warning for parts of Louisiana.(!Up to half a foot!) 3-5inches

Also, to note just looking I glanced there was a EF1 tornado touchdown.

Snow is expected from Texas to Alabama.

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LOL the kiddies in baytown are getting little "snow days" (they start later than usual (9:00am CT))

PS not gonna give an answer to how I made a snowman till I see a person guess at least

I wanna get your Post season minds working (I didn't get as much as the businesses near Broadway and TX 288)

as to why I din't get much considering the businesses are near me maybe having a lake near me as well has something to do with it?
Member Since: August 14, 2008 Posts: 0 Comments: 658
HI EVERYONE!!!

Snow in Houston eh? Wow then we might get snow here in SW LA! I am in Calcasieu Parish. I wonder if its gonna accumalate here?? Anyone know any info about that as of now?? (10:22pm Central time) THANKS! :)

Joanie
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Or what do you look for in terms of determining if high winds will be mixed to the surface or if any convection develops?
Member Since: October 21, 2008 Posts: 243 Comments: 3564
Drak, what is your thoughts on any high wind situation for SE MA?
Member Since: October 21, 2008 Posts: 243 Comments: 3564
I will Drak :)

in fact I made a snow man u guys wanna know how? I tell yall later in 10-20mins till then guess :)

I got a photo to prove it too :)


PS so if we have a hurricane there will be snow? LOL funny how that works fell bad for those who have blue on the roof

also my area is NW Pearland/Brazoria (south of Houston/Harris and east of Sugar land/Fortbend
Member Since: August 14, 2008 Posts: 0 Comments: 658
Thanks Drak...and we really did enjoy it. It's really the best kind of snow because there is just enough to enjoy and it goes away before it causes much trouble.

This is only the 2nd time I've seen snow fall. The first was Christmas Eve 2004.
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Quoting all4hurricanes:
2009
Ana, Bill, Claudette, Danny, Erika, Fred, Grace, Henri, Ida, Joaquin, Kate, Larry, Mindy, Nicholas, Odette, Peter, Rose, Sam, Teresa, Victor, and Wanda. To Early?


a bit :)
im just gettin' ready for winter
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... Snow falling across southeast Texas... .

A cold upper level low pressure system moving across Texas has
produced an area of light snow. Light snow fell early this morning
over parts of Washington... Burleson and Brazos counties. Light
snow redeveloped this afternoon as the upper low moved closer to
the Houston area. Although snowfall reports are incomplete... here
are a few unofficial totals through 830 PM from across southeast
texas:

College Station - 1 inch
Brenham - 1 inch
Bedias - 0.5 inch
Houston (se) - 0.2 inch
NWS office - 0.2 inch


When did it snow last??? snow flurries fell across the extreme
northern parts of the region on March 7th 2008 but the last
measurable snow occurred on April 7th 2007 north of a Caldwell to
Livingston line. One to two inches of snow fell on that Saturday.

The last measurable snow to fall in the Houston area fell on
Christmas eve in 2004. Snow amounts were a trace at
Intercontinental Airport... but southern suburbs like Pearland...
Webster and Clear Lake received 2 to 3 inches of snow. Further
south a band of heavy snow affected Wharton... Fort Bend and
Brazoria counties.

For what it's Worth... the last land falling hurricane on Galveston
Island before Hurricane Ike was Hurricane Jerry in 1989. There
was 1.7 inches of snow on December 22 1989. Hurricane Alicia made
landfall in 1983 and there were several days with snow flurries in
December of 1983. Just a coincidence... maybe... then again who knows?

Enjoy the snow tonight because it will melt quickly on Thursday
morning as temperatures warm into the lower 50s. Long range
forecasts do not support additional snow for the next seven to ten days.

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Crazy huh? It's still snowing in Clear Lake too.
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still snowing in Baytown Tx, must be 2 inches+
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Hey I have seen it snow 3 times in Houston in 1 year in 1973.
1989 2"
2004 1" 12" south of town
1982 1"
1979 1"
1963 2.5"
1895 20"
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Houston is officially in the twilight zone! It was 78 degrees yesterday and tonight I was driving in snow. It just boggles the mind! There is snow on the remnants of my hurricane Ike damage...couldn't have seen that coming! :-)
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Jim cantore said they have had 1/2inch so far in southeastern Houston(and an inch east of there), and it is now snowing in Galveston. Wow I'm really starting to feel left out here in Orlando with this system!
Member Since: July 13, 2007 Posts: 0 Comments: 950
How much snow has fallen in TX? Also surface low is over the North Central Gulf of Mexico.
Member Since: October 21, 2008 Posts: 243 Comments: 3564
Neighbors now building a snowman here in Baytown Tx and my wife says I need to go see it now!
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Wind evolution with this storm will be quite intersting as well as actual track compared to the models. We can see the upper level low over the Gulf Coast states.
Member Since: October 21, 2008 Posts: 243 Comments: 3564
OK bed time Good night all
Member Since: March 29, 2008 Posts: 0 Comments: 2338
Quoting TampaSpin:
I really appreaciated everyones support during these horrible days. Thank you all very much. I just updated my blog.....

TampaSpins Weather Blog Link
Welcome back TS!
Member Since: June 11, 2008 Posts: 24 Comments: 5910
Keep in mind that these December forecasts are a research project, and as yet have shown no skill in predicting the activity of upcoming hurricane seasons.


Right!
Thank you Dr. Masters!

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Quoting BtnTx:
I think it is non-info for someone to post on this blog their current interesting weather conditions without including their location. Not everyone who reads this blog has the time to read it 24/7 and create a database that tracks all bloggers location. I now step down from my soap box and go out to take more Baytown Tx snow pics.

I live in Fairfax, in northern VA I try to mention at least my general area when I talk about the weather here. But its not like any interesting weather ever happens here
Member Since: March 29, 2008 Posts: 0 Comments: 2338
also holy cow my windshield!

time for more pix :)
Member Since: August 14, 2008 Posts: 0 Comments: 658
Quoting BtnTx:
I think it is non-info for someone to post on this blog their current interesting weather conditions without including their location. Not everyone who reads this blog has the time to read it 24/7 and create a database that tracks all bloggers location. I now step down from my soap box and go out to take more Baytown Tx snow pics.


Im in NW pearland/brazoria (S of Houston)

PS first part may be tru but second part ummmm well check these persons by the name of Orcasystems and Zoomiami
Member Since: August 14, 2008 Posts: 0 Comments: 658
Fiji Meteorological Services (north of 25S, 160E-140W)
Wellington Meteorological Services NZ (south of 25S)

Tropical Disturbance Summary
============================
At 6 AM FST, Tropical Disturbance 03F (1001 hPa) located at 8.0S 162.0E. Position POOR based on Multispectral Infrared/Visible imagery and surface analysis. Sea surface temperatures is around 30-32C.

Tropical Disturbance Three lies to the west of an upper level anticyclone and in a moderately sheared environment. There is no definite low level circulation center and convection is confined to the north of the disturbance. Global models show no deepening of the system.

Potential for Tropical Disturbance THREE to develop into a tropical cyclone within the next 24 hours is LOW.
Member Since: May 24, 2006 Posts: 48 Comments: 43702
I think it is non-info for someone to post on this blog their current interesting weather conditions without including their location. Not everyone who reads this blog has the time to read it 24/7 and create a database that tracks all bloggers location. I now step down from my soap box and go out to take more Baytown Tx snow pics.
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2009
Ana, Bill, Claudette, Danny, Erika, Fred, Grace, Henri, Ida, Joaquin, Kate, Larry, Mindy, Nicholas, Odette, Peter, Rose, Sam, Teresa, Victor, and Wanda. To Early?
Member Since: March 29, 2008 Posts: 0 Comments: 2338
now we have ice pellets

PS RE 81 and 82:

LOL topsi turvi
Member Since: August 14, 2008 Posts: 0 Comments: 658
Quoting HurrikanEB:
Does some one whish to tell me why I, here in New york, am getting .3 inches of ice while Mississippi is getting 3 inches of snow.
(i know the reason, just wanted to point it out)

There be many a thing wrong in this world ;-)

The world inverted while we weren't looking
snow in Texas and rain in VA with 60 temp
I think mother natures on drugs for the moment.
I think she got addicted when it was 67 degrees in January earlier this year lol
Member Since: March 29, 2008 Posts: 0 Comments: 2338
Does some one whish to tell me why I, here in New york, am getting .3 inches of ice while Mississippi is getting 3 inches of snow.
(i know the reason, just wanted to point it out)

There be many a thing wrong in this world ;-)
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Thank for the video futuremet it was good
Member Since: March 29, 2008 Posts: 0 Comments: 2338
Now it is snowing in Baytown Tx. It really won't affect us much beyond the fact that the dog does not want to go out!
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Rare sleet in Baytown,TX for at least an hour now.
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Quoting all4hurricanes:
70 are you expecting a wet winter
lol
and TD27 is looking better


It looks like a line now...??
Member Since: October 15, 2008 Posts: 11 Comments: 2305
LATEST VIDEO FROM FUTUREMET PRODUCTIONS

Enjoy =D

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Snow surprises Houston-area residents
Copyright 2008 Houston Chronicle

Residents in the greater Houston area are reporting snowfall this afternoon.

As afternoon temperatures north of Houston hovered just above freezing on Wednesday afternoon snow fell across parts of the area.

According to the National Weather Service, areas such as Tomball and College Station all received snow flurries on Wednesday afternoon. Some areas, such as the Hwy 290 and Hwy 249 corridors, received moderately heavy snow at times.

The ground remains relatively warm so accumulation isn't expected in most areas, except in fields, yards and on the tops of cars.

Forecasters said snow is possible this evening northwest of a line from Freeport to Pasadena to Liberty, likely ending after about 9 p.m.

Although temperatures for much of the area may fall below freezing tonight, the precipitation should end, with the sun returning tomorrow to bring daytime highs into the mid- to upper-50s.

PS RE 72:

yes due to the maps that iv'e seen we may have a warm up on the way and then this warm up will go east but before it does it should be cold there in VA just have to give it a day

over in san antonio texas the day b4 we broke a high record of 85 F and now its cold there ( it was snowing there in the morning)
Member Since: August 14, 2008 Posts: 0 Comments: 658
SE Weather Forecast

The developing sub-synoptic scale cyclone has been fully established along the baroclinic zone near the Florida panhandle. This system is strengthening rapidly due to two vigorous anticyclones along its east and west, and instability caused by the strong temperature gradient. According to the CIMSS data, both lower level convergence and upper level divergence are abundant within the cold front. This low will cause welcoming rains here....my crops needs that. According to the local TV forecasts, high temperatures are expected to reach the upper-60s here in the treasure Coast. Albeit high temperatures are quite low, the overall low temperature is expected to be a fresh 51 degrees. This is because the system associated with the front is quite close to us, and clouds may still be present in the sky, thus, less thermal energy escapes (mini-greenhouse lol). In addition, the cyclone associated with the cool front is moving remarkably fast. Subsequent to the arrival of the front, an anticyclone is expected to set over florida within 24 hours, warming the air adiabatically. Beyond that, we have comfortable days ahead.

FutureMet
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70 are you expecting a wet winter
lol
and TD27 is looking better
Member Since: March 29, 2008 Posts: 0 Comments: 2338
Statement as of 6:14 PM CST on December 10, 2008


... Winter Weather Advisory in effect until midnight CST tonight...

The National Weather Service in Houston/Galveston has issued a
Winter Weather Advisory for periods of light snow and icy
roadways. The Winter Weather Advisory is in effect until midnight
CST tonight.

Surface temperatures have dropped to freezing across the area.
Light snow melting on contact with the ground has begun to freeze
on bridges and overpasses. Light accumulation of ice will occur
on elevated roadway surface such as bridges and overpasses. The
snow is expected to end between midnight and 3 am CST.

Roads... bridges... and overpasses in the warning area are slick
and hazardous. Accumulation of ice on roadways... bridges and
overpasses will make travel treacherous.




finally I knew they should have done this
Member Since: August 14, 2008 Posts: 0 Comments: 658

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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.