Nebraska's 2019 Flood Season ES OURCES

Nebraska’s 2019 Flood Season

        MA RT HA S HU L SK I, N E BR ASK A STATE CL I M ATOLOGIST
    A S S OCIATE P ROF ESSOR, S CHOOL OF N AT U RA L R ES OU RCES
                                                                    @mshulski3

The Nebraska State Climate Office                                        nsco.unl.edu

 MISSION
 Deliver science-based weather and climate information for
 decision-making.

 OBJECTIVES
   • Provide high quality and timely climate services.
   • Engage stakeholders to understand needs.
   • Operate a statewide weather network.

                      N E B R A S K A S TAT E C L I M AT E O F F I C E

Stakeholder base                                                 nsco.unl.edu

              N E B R A S K A S TAT E C L I M AT E O F F I C E

Weather monitoring                                               mesonet.unl.edu

              N E B R A S K A S TAT E C L I M AT E O F F I C E

Nebraska’s climate – historical trend

Nebraska’s climate – historical trend
• Future projections

Nebraska’s climate – future projections

• Wetter during winter and spring.
• More heavy rain events.
• Increased variability.

Setting the stage for March floods
• Antecedent conditions were critical.
• Overall cold and wet fall and winter.

Setting the stage for March floods
• Soils at or near saturation and frozen.
• Rivers and streams frozen.
• Several inches of water in the snowpack.

Along comes a late winter storm
                            March 13, 2019

• Mid-latitude cyclone
  rapidly intensified.

• Consistently in model
  runs ~10 days in        968 mb
  advance.

                                             https://earthobservatory.nasa.gov

Along comes a late winter storm
                            Watches, Warnings, Advisories Map from NOAA

• Mid-latitude cyclone
  rapidly intensified.

• Sustained high winds.

• Blizzard in the west,
  heavy rain in the east.

                              https://blogs.mprnews.org/updraft/2019/03/massive-storm-drives-multiple-warnings/

Extent of flooding
• Ice jams, snowmelt, heavy rain are
  contributors.

• Above flood stage for weeks.

• Record flooding at many
  locations.

• Damages estimated > $2B in     Posted on Twitter by Omaha/Valley National
  Nebraska.                      Weather Service

Impacts are wide-ranging
• State of Emergency declaration.

• Failure of Spencer Dam due
  to ice damage.

Impacts are wide-ranging
• 4 deaths; cattle losses; towns
  temporarily cut off; damage to
  homes, businesses, roads
  and fields; loss of
  stored grain; water quality
  concerns

Impacts are wide-ranging
• 4 deaths; cattle losses; towns
  temporarily cut off; damage to
  homes, businesses, roads
  and fields; loss of
  stored grain; water quality
  concerns

• Full impact yet to be realized.

Impacts are wide-ranging
• Offutt Air Force Base outside of Omaha, NE along the Missouri River.

Lead times
• Elevated flood risk category established late winter.

                                           • March 7th spring flood
                                             outlook from
                                             NWS Omaha/Valley
                                             media call.

Lead times

Warnings
• NWS updates going out regularly 3 days prior to event.

Outreach during the event
• Regular comprehensive
  briefings from the
  Omaha/Valley NWS
  office.

March 13th briefing
Outreach during the event

Outreach – pre-event

• Our office regularly contributes to the
  following outlets; flood potential
  discussed for the 2 weeks leading up to
  the event.
   • Cropwatch.unl.edu
   • KRVN radio, regional coverage
   • Market Journal television program

Outreach – post-event   flood.unl.edu

Outreach – post-event

Reduction of impacts?
• Broad-scale event that identified weaknesses
   o Gaps in preparedness and emergency operating plans
   o Communication of severity and taking action on the warnings
        Nebraska Emergency Management, FEMA stakeholder meeting (Apr 24)

Reduction of impacts?
• Snow control
  Culverts blocked with snow and crop debris  clearing out in
  advance of event?
• Ice control
  Open up river channels at problem areas and choke points?