NWS Alaska Region: Challenges in an Era of Changing Climate

PRIDE Alaska Coastal Wind/Wave Climatology Workshop

August 2-4, 2005

James Partain, ChiefEnvironmental & Scientific Services Division

NOAA NWS Alaska Region

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NOAA NWS Alaska Region - Overview

• 3 full-service Weather Forecast Offices

• 12 limited-service Weather Service Offices

• River Forecast Center• Tsunami Warning Center• 2 Aviation weather centers

NOAA NWS Alaska Region - Facilities

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Climate Impacts on Service Programs in NWS Alaska Region

• Aviation – more frequent icing, IMC conditions; aviators in bush still operating on old assumptions

• Public - more frequent “high amplitude” weather episodes (e.g. mid-winter thaws, coastal storms, windstorms, heavy precip)

• Marine – more frequent high-impact events, esp. in areas of sea-ice retreat

• Wildfire - more variable regime-dependent fuel-moisture conditions

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Climate Impacts on Service Programs in NWS Alaska Region (cont)

• Hydrology – greater variability in river volume & depth and related flooding and erosion; ice-dammed glacier lake releases

• Volcanic Ash – resuspension of relic ash from Katmai complex in Sept. 2003 led to redefinition of volcanic ashfall “event”

• Tsunami – sea-level rise may have eventual impacts

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Example: Bering Sea Storm of Oct, 2004

• Greatest short-term weather impacts of climate change are for coastal storms and attendant erosion– Later freeze-up, less extent and thinner sea-

ice, combined with loss of coastal permafrost, is a recipe for erosion from normal Fall storms

– Impacts magnified by greater wave size due to increased open-water fetch

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The Bering Sea Storm – Oct 18-20, 2004• Most important contributions from NWS are

Accuracy and Lead Time• The “bomb” of October 18-20, 2004,

illustrates the potential of our contributions– An ex-tropical cyclone rapidly deepened over a

period of several days to 940mb (hurricane intensity)

– Such storms normally handled very poorly by the models, even in the short-term

– In this case, atmospheric model had large-scale details, including amplification and track, predicted at 5-days lead time

– More importantly, run-to-run consistency was key to forecaster confidence in forecast/warning issuances.

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The Bering Sea Storm – Oct 18-20, 2004• Lead-time from WFO Fairbanks with first

service products was 3 days• Emergency managers were in continuous

contact with NWS offices Fairbanks, Nome and Kotzebue before, during and after the event

• NWS storm surge guidance also quite accurate and useful both to NWS staff and EMs

• Evacuations took place and physical mitigations were put in place for structure protection…no loss of life or significant injuries resulted.

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The Bering Sea Storm – Oct 18-20, 2004• Still…much erosion and property damage

occurred – $30M damage in Nome alone– 50+ feet of shoreline lost in Shishmaref…they

will not survive another such storm

• This storm showed:– The value of accurate, consistent objective

guidance in improving forecaster confidence in a developing storm

– The value of lead time– The value of NWS information to emergency

planners for disaster mitigation.

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Nome, AK – during the storm

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Nome, AK – Front Street

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A residence in Shishmaref – after the storm

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The Shishmaref school after the storm

A residence in Shishmaref – after the storm

The Shishmaref school after the storm