Active 2009 hurricane season predicted by Colorado State scientists
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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Updated: 5 min 33 sec ago
Light Snow
36 °F
Light Snow
Windchill: 30 °F
Humidity: 93%
Dew Point: 34 °F
Wind: 7 mph from the WSW
Pressure: 29.70 in (Falling)
Visibility: 9.0 miles
UV: 0 out of 16
Clouds:
Few 700 ft
Mostly Cloudy 2500 ft
Overcast 3900 ft
(Above Ground Level)
Elevation: 151 ft
Visibility 1/2 mile.....lol.
I've got to go to the grocery store momentarily. Gonna be difficult with that. lol
Incredible...it's moving in on New Orleans....
conchy: Good morning.
Wowsa..Link
Anyway, I'm off for now all. I've been up all night waiting on this snow, and now that I've seen my first significant snowstorm, I'm going to bed.
Statement as of 7:16 AM CST on December 11, 2008
... Winter Weather Advisory remains in effect until noon CST
today...
A Winter Weather Advisory remains in effect until noon CST today.
A cold and potent storm system will cause a cold rain to mix with
sleet this morning... then mix with and changeover to snow during
this morning rush hour... generally between 6 and 10 am.
Temperatures are expected to remain just above freezing with the
ground remaining relatively warm... however occasional heavy
bursts of snow may cause one to two inches of accumulation in
grassy areas with some icing and slushy conditions possible on
elevated bridges and overpasses. The snow is expected to change
back to a mix of light rain and light sleet by none... then end as
all light rain during the early afternoon hours as temperatures
warm back to the lower to middle 40s.
A Winter Weather Advisory means that periods of snow and sleet
will cause travel difficulties. Be prepared for slippery roads
and limited visibilities... and use caution while driving...
particularly on elevated bridges and overpasses.
Well said Shep, and good morning!.. I was going to say money. I was part of a citizens group working with FPL to choose a new transmission line path through Stuart. They said they were all for buried utilities, but could not cover the cost, and that there were indeed issues with burying tranmission lines.
Updated: 11 min 56 sec ago
Light Snow
37 °F
Light Snow Rain Ice Pellets Mist
Windchill: 28 °F
Humidity: 87%
Dew Point: 34 °F
Wind: 18 mph from the West
Pressure: 29.83 in (Rising)
Visibility: 1.0 miles
UV: 0 out of 16
Clouds:
Few 700 ft
Mostly Cloudy 1300 ft
Overcast 2200 ft
(Above Ground Level)
Elevation: 3 ft
Big Stuff falling UPTOWN!!!!
All very true Shep...I've also been told by FPL reps that buried utilities are still prone to problems from flooding that would especially be an issue in coastal areas due to salt-water intrusion from storm surge. Besides the expense issue I was told that aireal is more subject to storm damage, but easy to locate and fix problems...underground - less subject to damage, but when there is a problem...dificult to locate and repair.
Today
Snow...sleet...isolated thundersnow in the morning...then snow in the afternoon. Snow accumulations of 2 to 5 inches. Cloudy. Highs in the upper 30s. Northwest winds 10 to 15 mph with higher gusts. The chance of precipitation near 100 percent.
http://www.dotd.louisiana.gov/press/traffic_cameras/cameras_no.asp?camera=Cam5
Good explanation about the high voltage lines. Speaking of power, it has been flickering a bit here in the last hour, too.
Winter Storm Warning
URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE NEW ORLEANS LA
809 AM CST THU DEC 11 2008
...A WINTRY MIX OF PRECIPITATION IS EXPECTED THIS MORNING...
.A STRONG AND COLD UPPER LEVEL STORM SYSTEM COMBINED WITH LOW
PRESSURE OVER THE FLORIDA PANHANDLE WILL CAUSE RAIN TO MIX WITH
SLEET AND SNOW THIS MORNING ACROSS EAST CENTRAL LOUISIANA...
SOUTHEAST LOUISIANA AND EXTREME SOUTHWEST MISSISSIPPI AND COASTAL
MISSISSIPPI. THE WINTRY MIX HAS CHANGED OVER TO MOSTLY SNOW...
DURING OF THE MORNING RUSH HOUR ACROSS BATON ROUGE...THE NORTH
SHORE OF LAKE PONTCHARTRAIN...AND BEGINNING TO CHANGE OVER ON THE
SOUTH SHORE. AND THIS SNOW IS EXPECTED TO CONTINUE TO SPREAD EAST
THIS MORNING. THE GROUND IS EXPECTED TO REMAIN WARM WITH
TEMPERATURES ABOVE FREEZING...HOWEVER TWO TO FOUR INCHES OF SNOW
ACCUMULATION WILL BE POSSIBLE ON GRASSY AREAS...AND ELEVATED ROAD
SURFACES LIKE BRIDGES AND OVERPASSES. SNOW ACCUMULATION OF TWO
INCHES ON HIGHWAYS AND ROADWAYS. MANY ACCIDENTS WERE STATE POLICE
THIS MORNING IN THE BATON ROUGE AND THIS THREAT WILL SPREAD EAST.
I know someone that had no power for an extra week after a tree uprooted during gustav. The break in the line was some 1500 feet away from where the uprooted tree pulled on the buried lines.
Not since maybe 1988? I remember sledding on upside down garbage can lids at Highland Road park.
How's the bite down your way? Thinking about taking the kayak down to Hell's Bay after Christmas. Few mosquitos about now.
The benefit would be great for ice-storm prone areas...like last year about this time when almost the entire state of Oklahoma lost power after 2 days of rain at 28F.
Looks like we're in for some dicey weather this afternoon in East Central Florida as well.
Tornado watch and strong band of showers with front headed across the north & central parts of the state.
Updated: 3 min 21 sec ago
Heavy Snow
34 °F
Heavy Snow Fog
Windchill: 25 °F
Humidity: 87%
Dew Point: 30 °F
Wind: 12 mph from the WSW
Pressure: 29.84 in (Rising)
Visibility: 0.1 miles
UV: 0 out of 16
Clouds:
Overcast 400 ft
(Above Ground Level)
Elevation: 3 ft
L O L!
OSCEOLA AND VOLUSIA COUNTIES...INCLUDING THE ADJACENT NEAR SHORE
WATERS OF VOLUSIA COUNTY...
...THUNDERSTORM IMPACT...
AN ORGANIZED SQUALL LINE OVER THE EASTERN GULF OF MEXICO EARLY THIS
MORNING IS FORECAST TO MOVE ONSHORE THE WEST COAST AROUND SUNRISE
AND REACH THE INTERIOR SECTIONS OF EAST CENTRAL FLORIDA MID MORNING.
THIS LINE WILL THEN RACE RAPIDLY EASTWARD INTO THIS AFTERNOON...WITH
MOST OF THE ACTIVITY OFFSHORE THE EAST COAST BY MID TO LATE
AFTERNOON.
VERY STRONG WIND FIELDS ASSOCIATED WITH THE SQUALL LINE WILL BRING
THE THREAT FOR DAMAGING STRAIGHT LINE WINDS. ADDITIONALLY...THE
POTENTIAL ALSO EXISTS FOR A FEW STORMS TO ROTATE WITH ISOLATED
TORNADOES POSSIBLE....ESPECIALLY ACROSS THE NORTHERN SECTIONS THIS
MORNING. TORRENTIAL RAINFALL CAN BE EXPECTED BUT RAINFALL AMOUNTS
SHOULD BE LESS THAN ONE INCH GIVEN THE RAPID STORM MOTION...WHICH
WILL BE TOWARD THE NORTHEAST AROUND 50 MPH.
PERSONS IN EAST CENTRAL FLORIDA ARE URGED TO KEEP INFORMED OF THE
WEATHER TODAY AND BE READY TO TAKE QUICK ACTION AS STORMS APPROACH.
LISTEN FOR LATER STATEMENTS AND POSSIBLE WARNINGS.
Very. And I see it is 32 in Baton Rouge. If it doesn't warm a little, they are going to have bigger problems. These folks mostly do not have any experience driving in it and the many bridges will be just ice with snow on top of melted and then refrozen snow...in an area that has almost no road clearing equipment.
My lovely boss said to just stay home and off the roads. Yay. The subaru could surely handle it, but I have no faith in my fellow drivers.
Link
Still coming down and since then the flakes have gotten heavier. This would be a medium rain if it were rain.
Yes.
Today
Snow...sleet and slight chance of rain in the morning... then snow likely in the afternoon. Snow may be heavy at times in the late morning. Snow accumulations of 3 to 8 inches. Cloudy... brisk. Highs around 40. Northwest winds 15 to 20 mph with gusts to near 30 mph. The chance of precipitation near 100 percent.
just getting into the edge of that soggy business, you will be too pretty soon keeping an eye on that stripe between Ft Meyers and Arcadia...
Wowsa..
About the power line problem: Here in the UK we have also more aerial lines, the big transmission lines as well as the small distribution lines, but in Germany as well as in Finland and the other Scandinavian countries only the transmission lines are above the ground for the aforementioned reason (what thesheperd said)
All distribution lines are buried though. Someone mentioned that in this case every single town would have to have its own power plant but there is another solution: we have a little hut filled with transformers in every town. They take the high voltage from the transmission lines and distribute it in town at lower voltage.
The aerial transmission lines get rarely toppled over since they are built with sturdy four-post masts. The only storm hazard are branches or entire trees falling on the lines. The buried distributor lines are not prone to storms. In case of a power outage it is easy to restore the power because you only have to repair the supplying main line, the network of smaller lines underground is still intact.
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