Early 2011 Atlantic Hurricane Season Forecasts

By: Dr. Jeff Masters , 6:22 AM GMT on April 07, 2011

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Hi everybody, this is Dr. Rob Carver filling in for Dr. Masters. 

A continuation of the pattern of much above-average Atlantic hurricane activity we've seen since 1995 is on tap for 2011, according to the latest seasonal forecast issued April 6 by Dr. Phil Klotzbach and Dr. Bill Gray of Colorado State University (CSU). They are calling for 16 named storms, 9 hurricanes, and 5 intense hurricanes. An average season has 10 named storms, 6 hurricanes, and 2 intense hurricanes. The new forecast is nearly identical to their forecast made in December, which called for 17 named storms, 9 hurricanes, and 5 intense hurricanes. Only six seasons since 1851 have had as many as 17 named storms; 19 seasons have had 9 or more hurricanes. The 2011 forecast calls for a much above-average chance of a major hurricane hitting the U.S., both along the East Coast (48% chance, 31% chance is average) and the Gulf Coast (47% chance, 30% chance is average). The Caribbean is forecast to have a 61% chance of seeing at least one major hurricane (42% is average.) Five years with similar pre-season November atmospheric and oceanic conditions were selected as "analogue" years that the 2011 hurricane season may resemble: 2008, 1999, 1996, 1955, and 2006.  The first four years listed all had neutral to La Niña SST's during hurricane season, while 2006 had El Niño SST's.  The average activity for these years was 12.6 named storms, 7.8 hurricanes, and 4.8 major hurricanes.

This year, the forecasters have introduced a new statistical model for their  April forecasts.  There are four components in this model:

1. Average sea-level pressure in March around the Azores in the subtropical Atlantic.

2. The average of January through March sea-surface temperatures (SST's) in the tropical Atlantic off the coast of Africa.

3. Average sea-level pressure in February and March for the southern tropical Pacific ocean west of South America.

4. Forecasts of September's SST in the tropical Pacific using a dynamical model from the European Centre for Medium-Range Weather Forecasts (ECMWF) 

The first two components are loosely linked together.  Statistical studies have shown that a weaker subtropical high near the Azores, combined with warmer SST's off the coast of Africa in March are associated with weak winds near the surface and aloft from August to October.  This decrease in wind speeds reduces wind shear which can disrupt forming storms.  These March conditions also are associated with warmer SST's in August to October, which is also favorable for more tropical storms.   For this forecast, the first component is strongly favorable for increased hurricane activity, while the second component is weakly negative.

The last two components represent the changes in sea-surface temperature and sea-level pressure that are the El Niño-Southern Oscillation (ENSO).  Briefly speaking,  El Niño conditions (warm sea-surface temperatures) are not favorable for Atlantic hurricanes.  For more info on ENSO and hurricanes, Jeff has this article.

Using the ECMWF model as guidance (see Figure 1), the CSU group believes that SST's in the tropical Pacific will be neutral (less than 0.5°C from normal).  This would have a small negative effect on hurricane activity.  However, the tropical Pacific sea-level pressure shows that the atmosphere looks like a La Niña event is still going on.  This is strongly favorable for Atlantic hurricane activity in the CSU group's model.

Figure 1. Forecasts of El Niño conditions by 20 computer models, made in March 2011. The ECMWF forecast used by the CSU group is represented by the dark orange square.  The forecasts for August-September-October (ASO) show that 5 models predict El Niño conditions, 7 predict neutral conditions, and 5 predict a weak to moderate La Niña. El Niño conditions are defined as occurring when sea surface temperatures in the Equatorial Pacific off the coast of South America ( the "Niño 3.4 region) rise to 0.5°C above average (top red line). La Niña conditions occur when SSTs in this region fall to 0.5°C below average. Image credit: Columbia University.

How accurate are the April forecasts? While the formulas used by CSU do well in making hindcasts--correctly modeling the behavior of past hurricane seasons--their April hurricane season forecasts have had no skill in predicting the future. This year's April forecast is using a new system and has not yet produced a verified forecast.  The scheme used in the past three years successfully predicted active hurricane seasons for 2008 and 2010, but failed to properly predict the relatively quiet 2009 hurricane season. A different formula was used prior to 2008, and the April forecasts using that formula showed no skill over a simple forecast using climatology. CSU maintains an Excel spreadsheet of their forecast errors ( expressed as a mathematical correlation coefficient, where positive means a skilled forecast, and negative means they did worse than climatology) for their their April forecasts. For now, these April forecasts should simply be viewed as an interesting research effort that has the potential to make skillful forecasts. The next CSU forecast, due by June 1, is the one worth paying attention to. Their early June forecasts have shown considerable skill over the years.


Figure 2.
Accuracy of long-range forecasts of Atlantic hurricane season activity performed by Phil Klotzbach and Bill Gray of Colorado State University (colored squares) and Tropical Storm Risk, Inc. (colored lines). The CSU team's April forecast skill is not plotted, but is less than zero. 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.

2011 Atlantic hurricane season forecast from Tropical Storm Risk, Inc.

The  British  private  forecasting  firm  Tropical Storm Risk, Inc.  (TSR),   issued  their  2011  Atlantic hurricane season forecast on April 5. They are also calling for  a  very  active  year: 14. 2 named storms, 7.5 hurricanes, and 3.6 intense hurricanes. We would round that to 14 named storms, 8 hurricanes, and 4 intense hurricanes.   This  compares to their forecast issued in December of 15.6 named storms, 8.4 hurricanes,   and intense hurricanes. TSR predicts a 55%  chance  of  an  above-average  hurricane season, 28% chance of a near-normal season, and only a 17%  chance  of  a  below normal season. TSR bases their April forecast on predictions  that  sea  surface temperatures this fall in the tropical  Atlantic  will  be  above  about  0.08°C above average, and trade  wind  speeds  will  be  about 0.2  m/s  slower  than average.  The decrease in the trade wind speeds is favorable for enhanced hurricane activity, while the forecast SST's are expected to be neutral for hurricane activity.

TSR puts their skill level right next to the forecast numbers: 13% skill above chance at forecasting the number of named storms, 11% skill for hurricanes, and 10% skill for intense hurricanes. That's not much skill, and really, we have to wait until the June 1 forecasts by CSU, NOAA, and TSR to get a forecast with reasonable skill.

Rob's critiques of the April forecasts
I have to note that Jeff and I wrote this article together.  He wrote the general framework before the forecasts were issued, while I wrote the details based on the actual forecasts.  So the preceding text is a joint production.  However, I have a few observations to make that are my responsibility alone.

First, I am disappointed that the CSU group has changed forecast models only after three seasonal forecasts.  This makes it very difficult to assess the skill of the current forecast using past performance.  This is very important for forecast users, and they do it everyday.  For example, I tend to discount a forecast of rain if it comes from a source that over-forecasts rain (The boy who cried wolf problem).

In the documentation that came with the April forecast, the CSU group argue that the hindcasts show the new forecast model has skill.  However, I think hindcasts are a poor substitute for real forecasts in understanding the skill of a statistical forecast model, like that of the CSU's group.  As Jeff noted, the previous forecast model did well with the hindcasts and yet had mixed results with the actual forecasts.  This does not give me confidence that the new forecast model will be superior to the previous model.

From a philosophical viewpoint, I am inherently cautious about statistical forecast models like the one used by the CSU group.  Essentially, they look at what happened in the past and use that to predict the future.  However, for making forecasts, we assume that the relationships in space and time between the predictors (such as the average March sea-level pressure around the Azores) and the predictands (Atlantic hurricane activity) does not change as we move forward in time.  In a world with climate change, that's a tricky assumption to make.

In any event, it is customary in the meteorological community to continue running older forecast guidance models after the introduction of newer models.  This allows forecasters and forecast users to leverage their knowledge of the forecast skill of the older model and gain insight into the forecast skill of the new model.  The CSU group really should have included the forecast from the previous statistical forecast system in this forecast.     

I am uneasy with some of the methodology choices made in implementing the forecast model.  Data for the first three predictors was obtained from the Climate Forecast System Reanalysis (CFSR), NOAA's newest and most advanced reanalysis product.  However, CFSR data for 2010 and 2011 has not been released yet, so the CSU group used NCEP/NCAR Reanalysis (NNR), NOAA's first-generation reanalysis, to fill in the gaps.  Due to differences in design, resolution, etc., CFSR and NNR can have different depictions of the state of the atmosphere.  So using NNR's March 2011 average SLP instead of CFSR's could alter the forecast in unexpected ways.  It would be interesting to see how CFSR's 2010-2011 data changes the results. 

In any event, we will have to wait and see what the Atlantic hurricane season of 2011 brings.

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1083. emcf30
Member Since: August 7, 2010 Posts: 0 Comments: 1933
1081. Boca
Putting a number on "named" storms and relating it to history to me is bogus. Like "digital" television the picture becomes more clear with the development of the technology. These guys should eliminate the # of named storms and spend their time learning how to be more accurate with their landfall information. If they want to be in the prediction business and get all the headlines tell me who is going to win the next superbowl. Just sayin...
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Quoting plywoodstatenative:
All I know is that its been bloody hot here in South Florida.


Pretty hot here in Central Florida too! Had a high of 91 here!

I love this though, personally :)
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All I know is that its been bloody hot here in South Florida.
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Quoting caribbeantracker01:



yep seems right

Not drastically different from historical...

June:


July:


August:


September:


October:
Member Since: August 3, 2008 Posts: 16 Comments: 5871
Link

notice the area of disturb weather?? early start for the eastern pacific?
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Quoting caribbeantracker01:



yep seems right



I love those "higher concern areas" by Accuweather. We don't need Accuweather to tell that, we could just check the NOAA tropical cyclone climatology since those are always the biggest concern areas :)
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Link

yes explanation about a couple of things
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yep seems right
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1072. pottery
Skyepony, post 1054.

The last section, to Orca, was very well written. (as you usually do)
Simple, concise, understandable. Especially the point that every molecule is a heat-storing device. For a while...

Good post.
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1070. Gearsts
Quoting Skyepony:


Most likely NAO went Positive..I'd 1/2 expect it to stay higher for a few weeks.

Can you explain to me what the NAO is,and what causes it to go positive or negative?
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1069. Skyepony (Mod)
Quoting Gearsts:
Whats the cause for such a big increase in vertical shear?


Most likely NAO went Positive..I'd 1/2 expect it to stay higher for a few weeks.

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1068. Gearsts
Quoting JRRP:
Whats the cause for such a big increase in vertical shear?
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Wow Skye, there was a strong sandstorm yesterday in northern Germany as well.
Member Since: July 11, 2006 Posts: 14 Comments: 11173
1066. Skyepony (Mod)
Couple of minor nuclear events~ One USA, one India. Snow storm in Russia & this..

Very unusual sandstorm struck Bicske, Fejér County, Hungary on Saturday. A desert like sandstorm several animals drowned, the traffic had to be stopped in the area. The visibility was 2-5 feet in the county. The whole country was a hurricane-like storm winds, which caused significant damage.
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1065. Skyepony (Mod)
Wunder if Jeff is going to miss this severe weather out vacationing.


Lookin at the world..
Las Vegas officials say a lack of rain and little snowpack may lead them to declare a water emergency. The city this week imposed water restrictions that limit residents to one hour of outdoor watering per week. The restrictions could be upgraded to an all-out ban on outdoor watering by next week. State hydrologists tell the Las Vegas Optic the northern New Mexico town is in a particularly bad spot because it gets 90 percent of its water supply from the Gallinas River which is well below normal this year.
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hey emcf...yay, the reinforcements have arrived.
Member Since: July 11, 2006 Posts: 14 Comments: 11173
1063. emcf30
Member Since: August 7, 2010 Posts: 0 Comments: 1933
NATIONAL WEATHER SERVICE MORRISTOWN TN
303 PM EDT SAT APR 9 2011

VAC191-091930-
/O.CON.KMRX.TO.W.0013.000000T0000Z-110409T1930Z/
WASHINGTON VA-
303 PM EDT SAT APR 9 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 330 PM EDT FOR WASHINGTON COUNTY...AT 259 PM EDT... NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO INDICATE A TORNADO. THIS TORNADO WAS LOCATED NEAR GLADE SPRING...OR 6 MILES SOUTH OF SALTVILLE...MOVING EAST AT 40 MPH.

KYC051-121-091915-
/O.CON.KJKL.TO.W.0018.000000T0000Z-110409T1915Z/
CLAY KY-KNOX KY-
300 PM EDT SAT APR 9 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR NORTH CENTRAL KNOX AND SOUTH CENTRAL CLAY COUNTIES UNTIL 315 PM EDT...

AT 259 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS STORM WAS LOCATED NEAR GIBBS...OR 10 MILES NORTH OF BARBOURVILLE...MOVING EAST AT 45 MPH.

LOCATIONS IMPACTED INCLUDE...SPRULE...COTTONGIN...WOOLLUM...HAVEN...F OUNT...CAN NON...JONSEE... GREEN ROAD...GIRDLER AND HINKLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

Member Since: July 11, 2006 Posts: 14 Comments: 11173

Quoting Chicklit:
Wow Ben that's a big increase in SSTs over this time last year.

000


Indeed it is. should get warmer as we begin hitting those mid 90s soon.
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WWUS53 KJKL 091845
SVSJKL

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE JACKSON KY
245 PM EDT SAT APR 9 2011

KYC071-115-153-175-091900-
/O.CON.KJKL.TO.W.0017.000000T0000Z-110409T1900Z/
MORGAN KY-JOHNSON KY-MAGOFFIN KY-FLOYD KY-
245 PM EDT SAT APR 9 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR EXTREME NORTH CENTRAL FLOYD...NORTH CENTRAL MAGOFFIN... JOHNSON AND EAST CENTRAL MORGAN COUNTIES UNTIL 300 PM EDT...

AT 242 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE SQUALL LINE CAPABLE OF PRODUCING DAMAGING STRAIGHT LINE WINDS AND BRIEF RAIN-WRAPPED TORNADOES. THIS DANGEROUS STORM WAS LOCATED NEAR OIL SPRINGS...OR 8 MILES NORTHEAST OF SALYERSVILLE...MOVING EAST AT 50 MPH.
LOCATIONS IMPACTED INCLUDE...PAINTSVILLE...DOBSON...FLATGAP...BARNETT S CREEK...LEANDER...PATRICK...DENVER...WINIFRED...ST AFFORDSVILLE...FITZ...KERZ...BLAIR...COLLISTA...SI P...CHANDLERVILLE...GALEN...EAST POINT... WITTENSVILLE... STAMBAUGH AND HAGERHILL.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 3773 8307 3793 8304 3798 8286 3797 8282
3794 8279 3793 8276 3792 8274 3772 8273
TIME...MOT...LOC 1845Z 268DEG 43KT 3782 8291

Member Since: July 11, 2006 Posts: 14 Comments: 11173
Wow Ben that's a big increase in SSTs over this time last year.

000
NWUS53 KJKL 091850
LSRJKL

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JACKSON KY
250 PM EDT SAT APR 09 2011

..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..

1152 AM TSTM WND DMG BOWEN 37.84N 83.77W
04/09/2011 POWELL KY FIRE DEPT/RESCUE

UNCONFIRMED TORNADO DAMAGE. SEVERAL TREES DOWN AND STRUCTURES DAMAGED. MANY ROADS BLOCKED BY TREES.
Member Since: July 11, 2006 Posts: 14 Comments: 11173
Quoting cat5hurricane:

Sorry :-)


No problemo.
:)

Seems like they're looking for mid-afternoon storm initiation up there tomorrow but not impossible for Chi-land to be under moderate risk before 0600 CST 4/10, when today becomes tomorrow for SPC.
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April 9, 2010


April 9, 2011

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Member Since: July 11, 2006 Posts: 14 Comments: 11173
WesternKentuckyHazardsPageNOAA
Member Since: July 11, 2006 Posts: 14 Comments: 11173
Latest SPC Convective Outlook for today.

Click for probabilities and text.
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Noting you are posting tomorrow's outlooks, not today's. You had me confused there for a minute and I watch this stuff.
:)

Quoting KEEPEROFTHEGATE:


Quoting cat5hurricane:
The Moderate Risk zone has been adjusted ever so slightly to the east to include the city of Chicago and the greater Chicagoland Region.

Still not out of the realm of possibility that this risk still may be upgraded to a "High Risk" either later tonight or tomorrow morning.

Nonetheless, a widespread and significant severe weather outbreak is possible in both the slight and moderate regions highlighted.


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1252 PM EDT SAT APR 9 2011

...SEVERE THUNDERSTORM WATCH 112 IN EFFECT UNTIL 7 PM EDT THIS
EVENING...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EASTERN KENTUCKY.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

THERE IS A CHANCE FOR THUNDERSTORMS TODAY AND TONIGHT. SOME STORMS THIS AFTERNOON AND EVENING COULD BECOME SEVERE WITH DAMAGING WINDS AND LARGE HAIL THE PRIMARY THREAT. AN ISOLATED TORNADO IS ALSO POSSIBLE. THE THREAT OF FLASH FLOODING IS ALSO POSSIBLE TODAY WHERE STORMS REPEATEDLY MOVE OVER THE SAME AREA.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

THUNDERSTORMS ARE ALSO POSSIBLE SATURDAY NIGHT AND SUNDAY NIGHT THROUGH MONDAY NIGHT. THERE IS ALSO A SLIGHT CHANCE FOR THUNDERSTORMS THURSDAY AND THURSDAY NIGHT.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND EVENING TO REPORT ANY INSTANCES OF WIND DAMAGE... LARGE HAIL...SIGNIFICANT FLOODING...FUNNEL CLOUDS OR TORNADOES TO THE NATIONAL WEATHER SERVICE.

$$

Member Since: July 11, 2006 Posts: 14 Comments: 11173
Tornado watch has been issued pretty high probs too... I am in that watch
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1049. emcf30
Quoting Tazmanian:
ah nuts no high risk

My bet it will be tommorrow
Member Since: August 7, 2010 Posts: 0 Comments: 1933
1047. emcf30


How would you like to be hit by this. 7" diameter, 13.75" circumference and weighed just under 1lb fell during Nebraska storm in 2003. I believe this is still the record hailstone for the US tho not sure.
Member Since: August 7, 2010 Posts: 0 Comments: 1933
ah nuts no high risk
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1045. Skyepony (Mod)
Quoting Tropicsweatherpr:


That cold pool is very big.




That cool pool is a shallow remnant, with much heat lurking below, a spit on the surface left of it's former huge deep, cool pool.


Aussie~ NOAA who's pretty conservative with the enso forecasts put out the monthly 2 days ago.

Synopsis: A transition to ENSO-neutral conditions is expected by June 2011.

Though I think I as usual was looking much farther beyond the next 2-3 months. Check the T-depth anomaly huge change there the last 30 days.


Orca~ The exact % would be available if we could get a satellite up there to measure how much aerosol emissions are forcing things in the direction of cooler. These things are chemically proven. They've got high, long flight planes that see the effects in small picture in time moments. But the big pic with the exact numbers eludes us as long as our atmosatellites keep landing in the ocean. There are some published estimations (a range of % each contributes) out there if you want to look. There are several factors both human & not that are pushing climate in both directions..Some more straight forward than other. If I remember right~ Black soot from burning coal has a specific (maybe 5ºs) of forcing toward warm. & then there is the details..of the devil like the ocean is taking up a huge amount of that warming. Many people don't get that the forcing from that radiates back to us at some point. To force it with CO2 then call the heat it radiates when it's saturated natural wouldn't be correct to blame wholly on natural processes. To sit & wait to act when we have the math all worked out on the big pic is ridiculous. We've known for decades exactly how much heat certain molecules hold & for how long, thanks to Chemistry. We know we are putting tons up there every second of these molecules & that the permafrost that is helping to melt releases more & of a longer lasting variety.
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Doing home work (public budgeting...sigh), and so must break for weather rather frequently in order to stay awake:

Hazardous Weather Outlook
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
1204 PM CDT SAT APR 9 2011

IAZ004>007-015>017-023>028-033>039-044>048-057>05 9-101715-
EMMET-KOSSUTH-WINNEBAGO-WORTH-PALO ALTO-HANCOCK-CERRO GORDO-POCAHONTAS-HUMBOLDT-WRIGHT-FRANKLIN-BUTLER-B REMER-SAC-CALHOUN-WEBSTER-HAMILTON-HARDIN-GRUNDY-B LACK HAWK-CRAWFORD-CARROLL-GREENE-
BOONE-STORY-AUDUBON-GUTHRIE-DALLAS-
1204 PM CDT SAT APR 9 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

NUMEROUS THUNDERSTORMS ARE EXPECTED TO DEVELOP BY THIS EVENING ACROSS NORTHERN IOWA. A MODERATE RISK OF SEVERE WEATHER EXISTS IN NORTHERN AND CENTRAL IOWA DURING THIS TIME. THE POTENTIAL FOR VERY LARGE HAIL... DAMAGING WINDS AND TORNADOES WILL EXIST FOR THE AREA... ESPECIALLY THIS EVENING.

RIVER FLOOD WARNINGS ARE ALSO IN EFFECT FOR PORTIONS OF THE UPPER
DES MOINES RIVER VALLEY. PLEASE REFER TO THE NATIONAL WEATHER
SERVICE WEBSITE AT WEATHER.GOV/DESMOINES FOR FURTHER DETAILS.


.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

LARGE HAIL...DAMAGING WINDS AND A FEW TORNADOES WILL BE POSSIBLE ON SUNDAY AFTERNOON...ESPECIALLY ALONG AND EAST OF INTERSTATE 35.THERE IS A POTENTIAL FOR HIGH WINDS SUNDAY AFTERNOON FOLLOWING THE PASSAGE OF THE DRY LINE DURING THE MID TO LATE AFTERNOON HOURS. AT THIS TIME...THE POTENTIAL IS CONDITIONAL...BUT IF IT OCCURS WINDS MAY GUST WELL ABOVE 50 MPH FOR A PERIOD OF TIME FROM LATE AFTERNOON THROUGH EARLY EVENING.
STRONG AND GUSTY WINDS ARE LIKELY MONDAY WITH GUSTS IN EXCESS OF 45 MPH.

.SPOTTER INFORMATION STATEMENT...

AN EMERGENCY MANAGERS WEBINAR IS SCHEDULED FOR 230 PM TODAY...TO DISCUSS THE SEVERE WEATHER POTENTIAL FOR THIS EVENING THROUGH SUNDAY.

SPOTTER ACTIVATION IS EXPECTED THIS EVENING AND AGAIN ON SUNDAY AFTERNOON.

$$

Member Since: July 11, 2006 Posts: 14 Comments: 11173
1043. KEEPEROFTHEGATE (Mod)
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1042. JRRP
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1041. KEEPEROFTHEGATE (Mod)
mod risk remains




1233 PM CDT SAT APR 09 2011

VALID 101200Z - 111200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF FAR SOUTHEAST
MINNESOTA...EASTERN IOWA...NORTHERN ILLINOIS AND THE SOUTHERN
TWO-THIRDS OF WISCONSIN...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE UPPER MS VALLEY/UPPER
GREAT LAKES REGION SWWD INTO NERN TX...

...SYNOPSIS...
POWERFUL UPPER TROUGH IS PROGGED TO CONTINUE EWD ACROSS THE CENTRAL
THIRD OF THE CONUS THIS PERIOD...ACCOMPANIED BY A VERY STRONG SWLY
JET ON THE ERN FRINGE.

THIS TROUGH WILL SUPPORT SURFACE LOW DEVELOPMENT ACROSS THE UPPER
MIDWEST...WITH A TRAILING COLD FRONT FORECAST TO SHIFT EWD ACROSS
THE PLAINS. THIS FRONT WILL BE A FOCUS FOR A WIDESPREAD AND
POTENTIALLY SIGNIFICANT SEVERE WEATHER EVENT THIS PERIOD.

...UPPER MIDWEST/UPPER MS VALLEY/WRN UPPER GREAT LAKES REGION...
POTENTIALLY-SIGNIFICANT SEVERE WEATHER EVENT -- INCLUDING THE
POTENTIAL FOR A FEW STRONG TORNADOES -- APPEARS TO BE UNFOLDING FOR
SUNDAY AFTERNOON AND EVENING.

AS THE LARGE UPPER TROUGH APPROACHES...AIRMASS WILL CONTINUE
MOISTENING/DESTABILIZING WITH TIME. THE BOUNDARY LAYER WILL LIKELY
REMAIN CAPPED THROUGH MID AFTERNOON...BUT FORCING ALONG THE
ADVANCING COLD FRONT -- AND INVOF THE SURFACE LOW/WRM FRONT ACROSS
SERN MN/ERN IA/SRN WI -- SHOULD ALLOW STORMS TO INITIATE BY 20-22Z.
STRONG LOW-LEVEL FLOW BENEATH 80-PLUS KT MID-LEVEL SWLYS WILL
PROVIDE SHEAR VERY SUPPORTIVE OF SUPERCELLS -- AND THUS STORMS WILL
RAPIDLY BECOME SEVERE AS THEY INCREASE AND SPREAD QUICKLY EWD ACROSS
THE UPPER MS VALLEY AREA...FUELED BY MODERATE INSTABILITY. GREATEST
TORNADO THREAT WILL LIKELY EXIST ACROSS ERN IA AND INTO SRN WI/NRN
IL...NEAR THE SURFACE LOW AND WARM FRONT WHERE LOW-LEVEL SHEAR WILL
BE MAXIMIZED. VERY LARGE HAIL AND DAMAGING WINDS ARE ALSO EXPECTED
-- WITH THE DAMAGING WIND THREAT EXPECTED TO INCREASE WITH TIME AS
STORMS LIKELY BECOME MORE LINEARLY ORGANIZED WITH TIME.

MORE ISOLATED STORMS WILL LIKELY DEVELOP SWD ALONG THE FRONT FROM MO
INTO NERN TX. WHILE TORNADO THREAT WILL NOT BE AS GREAT...LARGE
HAIL AND DAMAGING WINDS WILL BE POSSIBLE.

STORMS WILL SHIFT EWD OVERNIGHT -- BUT SHOULD WEAKEN WITH TIME WITH
THE LOSS OF HEATING. SEVERE POTENTIAL IS MOST LIKELY TO LINGER
ACROSS THE UPPER GREAT LAKES/UPPER MIDWEST...WHERE STRONGEST FORCING
-- AND THUS GREATEST CAPE/SHEAR COMBINATION -- IS FORECAST.

...LOWER GREAT LAKES REGION...
WHILE WEAKER INSTABILITY IS EXPECTED ACROSS WRN NY/WRN
PA...AFTERNOON CONVECTION CRESTING THE UPPER RIDGE AND CROSSING SRN
ONTARIO MAY CROSS THE LAKES AND BRING A LIMITED THREAT FOR DAMAGING
WINDS AND MARGINAL HAIL TO THIS REGION. ANY THREAT SHOULD DIMINISH
DURING THE EVENING WITH THE ONSET OF DIURNAL COOLING.
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1040. emcf30
Friday 4/8/11
For several days, we%u2019ve been talking about a weekend storm system that has every indication of becoming a classic example of an early spring tornado outbreak.
The storm system we%u2019ve been talking about enters the weather picture Saturday Afternoon. You can see a large slight risk area now posted. A warm front is expected to swing through the state of Iowa as the surface low pressure system remains just to the west. This will be the focus of severe weather during the late afternoon, evening and overnight hours across the state. All modes of severe weather will be possible.

day2probotlk_0600_anyAs you can see the greatest risk area lies in portions of western and northern Iowa. Besides the possibility of a few tornadoes, the primary threat on Saturday appears to be very large hail, especially in southwest portions of Iowa. These thunderstorms may continue across parts of the state well into the night and into Sunday morning.

This is where the forecast becomes especially troublesome, as a near-perfect set up takes place right on top of Iowa. There are two distinct features that could produce a serious and widespread damaging event across the state.

As we start the day on Sunday, the warm front should be north of Iowa, leading to very warm and humid conditions across the state, especially for this time of year. A dry line is expected to develop ahead of the cold front as the surface low begins tracking through the Upper Midwest. This is where it is expected widespread and rapid development of thunderstorms that could take just a matter of minutes to explode into supercells.

day3otlk_0730 Overall, the atmospheric setup is nearly perfect for a major outbreak. Low level shear, available energy and a whole host of other factors are giving forecasters and storm chasers major cause for concern. As a result,the Storm Prediction Center has already posted a moderate risk for portions of Iowa on Sunday. I would not be surprised to see some areas upgraded to a high risk for severe weather by Sunday. With all modes of severe weather possible, and a good chance of many tornadoes, including some strong twisters that stay on the ground for a long time, it%u2019s safe to say at this point that Sunday has the potential to go down as a historic outbreak of severe weather.
It%u2019s expected the storms could travel at a rate of between 50 and 60mph. This will also greatly enhance the danger of any tornadoes that form because they too will be fast moving and limit the amount of warnings areas at risk might see. A set up like this does not happen very often in Iowa and with it being so early in the severe weather season, many could be complacent about taking the appropriate precautions.

day3prob_0730 These are some of the highest risk probabilities you can see, especially 3 days away from a severe weather event. This is a storm that you will hear a lot about on television as it approaches. We storm chasers love a classic set up that provides us a chance to get up close and personal with a tornado, but this is different. This is the type of setup that could have disastrous consequences for any town, structure or person caught in its path.
Member Since: August 7, 2010 Posts: 0 Comments: 1933
Quoting Neapolitan:

And I've answered you many, many times; perhaps you've missed that. The best science says that the rise in atmospheric CO2 over the past 200 years has been caused entirely by the burning of fossil fuels coupled with deforestation, and--more and more frequently--the feedback mechanisms (permafrost thawing, etc.) initiated by them. So if you really feel that you somehow need a rock-solid number, I'll give you one: how about 100%?

But just out of curiosity, how high would that percentage have to be to motivate you to action?


So your saying its 100% man made... yet the earth has been warmer many times in cycles.

I actually do my part when ever possible.. including 2 hybrid vehicles (yes, even my truck). How about you?

I just don't believe its all man made... we are part of the equation... but I don't believe we are the whole equation.

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We say it every year, but this year feels kinda ominous due to SSTs and how the Nino-to-Neutral is stacking up. Should be interesting.
Member Since: July 11, 2006 Posts: 14 Comments: 11173
Quoting FirstCoastMan:



Are you sure that for this...Oh I see it.Ah ish.If atmospheric conditions are good then.That only means trouble.
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Quoting Orcasystems:


I have asked you multiple times... for a number..any number.. even one per reviewed and verified by one of your esteemed sources... there isn't one?

You cannot keep coming on here and beating yours/ours/theirs head against the wall... when you cannot even prove a percentage?

Give me a proven verified number??

Do we contribute.. yes... are we 100% responsible... 50%... 25%.... tell me.

"most of it" and "all of it". is not a scientific anything.

And I've answered you many, many times; perhaps you've missed that. The best science says that the rise in atmospheric CO2 over the past 200 years has been caused entirely by the burning of fossil fuels coupled with deforestation, and--more and more frequently--the feedback mechanisms (permafrost thawing, etc.) initiated by them. So if you really feel that you somehow need a rock-solid number, I'll give you one: how about 100%?

But just out of curiosity, how high would that percentage have to be to motivate you to action?
Member Since: November 8, 2009 Posts: 4 Comments: 13457
1035. KEEPEROFTHEGATE (Mod)
Quoting Chicklit:
Hi Keeper,
We're 84-point-something now and will be in the 80s all week.


ya you should start to see the first of the sea breeze action this week coming up as well

spring rushes towards summer
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Quoting Neapolitan:

My guess is that global warming arguments will go away at roughly the same time that global warming itself goes away. Until then, well, what is, is.

Australia produces 1.2% of the worlds pollution. As of July 1 2012 we will be taxed $35/tonne of CO2 a household produces. This includes businesses including steel producers like Bluescope Steel formally BHP steel. This will force these manufacturing companies out of Australia to more than likely China. This will cause the employment rate to go from it's current 5.5% to 10-15%. The introduction will also force the price of everything needed to live to go up. This new tax will cost the average household $1580 a year, if including the cost of the tax on everything else..... who knows.... $5000 extra a year.... ???

This all from a report from Prof. Ross Garnaut who is a Distinguished Professor of Economics at the Australian National University and both a Vice-Chancellor's Fellow and Professorial Fellow of Economics at The University of Melbourne. Not a climate scientist. feel free to google his name to find out which company boards he's on. I think his mind isn't on climate but on whats going to be streaming into his bank account, if you get what i mean.
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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.