New hurricane forecast products with more lead

time for disaster preparation by electric

utilities

Iris Grossmann, PhD.With Phil Klotzbach, Ph.D. (Colorado State) and Mitch

Small, Ph.D. (CMU)Center for Climate and Energy Decision Making

(CEDM)

Image source: Pepco

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Motivation: Tropical cyclones (TC) may become more intense in a warmer world….

2Center for Climate and Energy

Decision Making

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2008 Hurricane season: 7 TC landfalls in US,40 million customers experienced outages

TS Fay

Cat 1 Dolly

Cat 2 Gustav

TS Edouard

Cat 2 Ike

TS Hanna

Cat 1 Kyle

Image source: NOAA/NHC

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Utility preparation prior to expected TC landfall

Assess needs for line & tree crews and equipment Request crews through mutual assistance groups Ready crews; plan transportation, lodging etc Deploy crews Revise...

Problems: 1. Preparation is expensive2. Need to prepare well in advance, e.g., at least 3 days, but

forecasts at that time are not very good.

Center for Climate and Energy Decision Making

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How good are hurricane track forecasts?

Center for Climate and Energy Decision Making

130-255m error

Image source: NOAA/NHC

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Very intense storms may change intensity too quickly for accurate forecasting

Center for Climate and Energy Decision Making

Cat 5Cat 4Cat 3Cat 2Cat 1

Cat 5Cat 4Cat 3Cat 2Cat 1

Hurricane Felix2007

Hurricane Opal1995

Image source: NOAA/NHC

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2-phase approach to TC forecasting & power restoration (project in review with NSF Infrastructure Management & Extreme

Events)

I. New statistical TC forecasting schemeII. Dynamic programming model for power line

restoration planning

Center for Climate and Energy Decision Making

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2-phase approach to TC forecasting & power restoration (project in review with NSF Infrastructure Management & Extreme

Events)

I. New statistical 5-14 day TC forecasting schemei. Assess probability that TC will undergo rapid intensification (RI)

and probability that it will become long-lasting major TCii. Assess likelihood ranges for landfall locations, using historic

tracks in proximity to given TC, analog years, and prevailing tracking patterns during given season

Short-term (conventional) forecast and individual utility planning

New long-range forecast scheme and individual utility planning

Short-term (conventional) forecast and utility consortium planning

New long-range forecast scheme and utility consortium planning

II. Dynamic programming model for restoration planning

i. Successive evaluation of optimal allocation / deploymentii. In each step: should crews stay or move?iii. Compare cost across 4 options below:

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1. Thermal energy from difference between warm ocean and colder atmosphere

2. Unstable atmosphere3. Mid-tropospheric moisture4. Low vertical wind shear5. Vorticity (spin)6. Coriolis force

Forecast scheme makes use of conditions that determine TC formation and intensity

Center for Climate and Energy Decision Making

Image source: Wikipedia

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Early stage storms: “invests”

Center for Climate and Energy Decision Making

Bottom: fully formed hurricane

Image sources: NOAA/NHC, NASA

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Preliminary studies till date (in collaboration with forecaster Phil Klotzbach)

Center for Climate and Energy Decision Making

I. Pilot-study: scheme to evaluate potential for TC formation

II. Assess probability that an invest will spend „long“ time period in major TC stage

III. Assess probability of rapid intensification (RI)IV. Tracking patterns and analog years

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I. Pilot study on TC formation forecasting scheme

Center for Climate and Energy Decision Making

MDR Genesis Parameter (10-20°N, 20-60°W)

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I. Pre-cursor signals for TC formation (from Phil Klotzbach)

9 – 11 Day Lead 6 – 8 Day Lead

3 - 5 Day Lead 0 - 2 Day Lead

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Conditions at time of initial TC formation for soon-to-be major hurricanes vs weaker storms

Center for Climate and Energy Decision Making

• 56% less wind shear than non-developing invests, 44% less than all hurricanes.

• 16.5% more humidity than non-developing invests, 3% more than all hurricanes.

• 1.6K warmer sea surface temperature than for non-developing invests, 0.8K warmer than for all hurricanes.

II. Assess probability that invest will spend “long” time period in major TC status

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Relationship between duration in major TC status and damages

Center for Climate and Energy Decision Making

Hours as major hurricane (mean)

Hours as major hurricane (median)

All major hurricanes 1900-2008

57.7 42.0

Major hurricanes that made landfall

59.6 42

Major hurricanes causing US damages ≥ $1 billion

68.4 48

40% of hurricanes that spend at least 36 hours in major hurricane status cause ≥ $1 billion in (normalized) US damages.

16Center for Climate and Energy

Decision Making

III. Assess probability of rapid intensification by MJO phase during TC formation

RI 25kt RI 30kt RI 35kt RI 40kt +

Phase 1& 2 76% 67% 47% 38%

Phase 6 & 7 33% 22% 22% 6%

The MJO (Madden Julian Oscillation) is a large-scale pattern of variability on the 30-90 day scale.

It is not free-standing but travels eastward as an atmospheric wave.

It progresses through 8 phases.

Probability of RI by MJO phase during which TC formed

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IV. Steering patterns: pattern persistence

1951

2004

Image source: NOAA/NHC

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2010

1954

IV. Steering patterns: pattern persistence (2)

Image source: NOAA/NHC

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Other climate work that I am engaged in

Center for Climate and Energy Decision Making

Decision-analysis of hurricane modification (completed) Assessing and communicating non-stationary hurricane

return periods given multidecadal variability and global warming (project in review at NSF Earth System Models)

Assessment of hurricane risks to off-shore wind turbines (published in PNAS)

Assessment of changes in US Southwest drought risks “Force majeure“ – due to climate change, climate

hazards may no longer be classifiable as act of God Evaluation of solar insolation data for large-scale solar

networks (in review at Renewable & Sustainable Energy Reviews)

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Thank you for your attention

Center for Climate and Energy Decision Making