Daniel Nietfeld – NOAA/NWS/WFO Omaha NE Kansas City IWT Workshop: Using the WAS*IS Approach January 22, 2009.

Impact on policy from three severe weather events in the Omaha area in June, 2008

Daniel Nietfeld – NOAA/NWS/WFO Omaha NE

(and many other issues raised)

Kansas City IWT Workshop: Using the WAS*IS Approach January 22, 2009

Is this something you would want to be warned about? Would you expect the sirens to be blown?

What was that ? Did it seem dangerous, or even life-

threatening? Rear flank downdraft (straight-line

winds) Behind a tornadic supercell (Hallam, NE) What would be the best way to handle

this scenario with a warning, and any associated siren blowing ???

What would be a good polygon solution for this scenario ???

May 22, 2004 Hallam, Nebraska F4

T

June 8 2008: Omaha, Nebraska(mid-morning)

June 8 2008: Omaha, Nebraska

NWS WCM

Home Owner

Saw

2:10 – 2:30 AM June 8 2008

Storm-Relative Velocity

The Omaha Policy on 8 June, 2008

Sound the sirens when the NWS issues a tornado warning

IT HI T WITHOUT ANY WARNING !!!!! (From the NWS, or from a siren

perspective)

June 8 2008: Omaha, Nebraska

NWS WCM

Home Owner

Saw

The Aftermath of 8 June Significant outcry Meeting with the Mayor and Staff Press Conference 3 days of news coverage

Google “Omaha” “Tornadoes” “June 8”

11 June 2008

Xavier

14 Yr Old Boy Scout

Note the scar

11 June 2008

• 4 Killed

• 48 Injured

Had an “outdoor warning device” and NOAA Weather Radio

Boy Scout Policy Changes Must camp with a Severe Wx Trained

adult Severe weather training courses Involving the IWT in groups such as Boy

Scouts Sirens / Outdoor warning devices Storm Shelters

What IF ? Do you want a TOR Inside a SVR ???

June 11, 2008 Tornado Warnings in the Omaha Area

Tornado Warnings off/on 715 pm – 10 pm

Sirens off/on for nearly 3 hours Were polygons too large?

(We were operating without a radar at times)

Should we take these political boundaries into account?

27 June 2008

3-D KOAX Reflectivity at 2159 UTC (courtesy GR Level 2 Analyst)

June 27, 2008

June 27 Severe Thunderstorm Hurricane force winds Lasting for several minutes Damage and debris was widespread NO TORNADOES

(?What is the best product for this scenario?)

Damage Survey

Event ImpactsStorm statistics:•Path length: 90 miles•Path width: 4 to 6 miles•Estimated maximum wind speeds: 110-115 mph (EF2)•One fatality (tree fell on car in Council Bluffs, IA) and several minor injuries•Damage estimate: $53+ million in Douglas County (Omaha)

MOTIVATION! New Policy from Lessons

Learned! … When to activate:  When the National Weather Service initiates a

Tornado Warning for any portion of Douglas County. When a public safety official or trained storm-spotter

states that s/he is in site of a rotating funnel cloud or tornado within Douglas County.

When Douglas County 911 receives credible reports of damage or the eminent threat of hurricane-force sustained winds equal to or greater than 74 mph.

New Policy… During night-time conditions or in the

absence of adequate warning, the on-duty 911 supervisor can direct an activation of the outdoor warning sirens if he/she determines that lives may be saved and injuries averted by alerting the public to the severe weather condition.Getting a bit vague here…

Conclusions Original Policy was product driven and

failed when the science did not permit the proper product to be issued

Revised Policy was more impact driven, and worked when a life-threatening (but non-tornadic) weather event occurred

What other lessons can be learned… (?) Kansas City Metro area ? Lincoln, Nebraska – spotter sighting

only Minimizing False Alarms

Flash flood policies ?

Post-Event Activities June 8

Local Media flurry Live press conference with Mayor and 911

Director June 11

National Media June 27

Local Media Insurance companies, lawyers, roofing

companies, etc.

Discussion Questions Siren Policies

Scout Camp issues Shelters Sirens Should NWS Warnings have GIS data? (camps, etc…)

Polygon methodologies Products that fit the event (wide range of Severe)

Impact on policy from three severe weather events in the Omaha area in June, 2008

Daniel Nietfeld – NOAA/NWS/WFO Omaha NE

(and many other issues raised)

Kansas City IWT Workshop: Using the WAS*IS Approach January 22, 2009