Rapid Cyclogenesis and Societal Impacts of November Great Lakes Cyclones

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Rapid Cyclogenesis and Societal Impacts of
November Great Lakes Cyclones

• Stacie Bender Nicki Hickmon
• April 23, 2001

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Project Outline

• Application of Theory
• Petterssen-Sutcliffe Cyclone Development
• Effects of Lakes on the Cyclones
• Diabatic Heating Effects
• Effects of Cyclones on the Lakes
• Waves
• Societal Impacts of Great Lakes Cyclones
• Sinking of the Edmund Fitzgerald (November 1975)

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Application of Theory

• Petterssen-Sutcliffe Cyclone Development
• Development measured in terms of local vorticity
  change at sea level
• ?Qo/?t AQ (R/f)?2(g/R) AT S H
• 4 terms contribute to the local vorticity change
• Vorticity Advection (AQ)
• Thickness Advection (AT)
• Adiatbatic Influence (S)
• Diabatic Effects (H)

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P-S VORTICITY ADVECTION

• Development at the surface is a function of
  vorticity advection at the level of nondivergence
  (LND).
• Positive Vorticity Advection at 500 mb above the
  position of the surface low will aid in cyclone
  development.

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P-S 500 mb VORTICITY ADVECTIONEta Analysis for
11/09/98 1200 UTC
L (996 mb)
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P-S VORTICITY ADVECTIONEta Analysis for
11/10/98 1200 UTC
L
(972 mb)
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P-S THICKNESS ADVECTION

• Surface development is also a function of
  thickness advection ahead of the surface system.
• Thickness advection patterns dictate where the
  surface low moves toward and away from.
• Warm thickness advection supports cyclogenesis.
• Surface pressure falls in warm thickness
  advection areas because of
• Hypsometric reasoning
• Enhanced divergence ahead of the upper and mid
  level trough if the curvature is sharp
• Cold thickness advection opposes cyclogenesis.
• Surface pressure rises in cold thickness
  advection areas because of
• Hypsometric reasoning
• Enhanced convergence behind the upper and mid
  level trough if the curvature is sharp
• The surface low propogates towards the falling
  pressures that were created by warm thickness
  advection.

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P-S THICKNESS ADVECTIONEta Analysis for
11/09/98 1200 UTC
L
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P-S Thermal AdvectionEta Analysis for 11/09/98
1200 UTC

• CAA

L
WAA
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P-S THICKNESS ADVECTIONEta Analysis for
11/10/98 1200 UTC
L
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P-S Thickness/Thermal AdvectionEta Analysis for
11/10/98 1200 UTC
WAA
L
CAA
CAA
WAA
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P-S Adiabatic Influences

• Development of surface low is contingent upon
  potential energy being available to the system.
• Cyclones that ingest dry, stable air rarely
  develop.
• This provides a large negative term to the LHS of
  the P-S Development Equation.
• Ingest of dry, stable air prevents cyclogenesis.
• Cyclones that ingest moist, unstable air CAN
  develop, depending on other factors.
• The ingest of moist, unstable air is a NECESSARY,
  but not SUFFICIENT condition for cyclogenesis.
• If moist, unstable air is ingested, the gate is
  opened, and cyclogenesis can proceed.

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PS Adiabatic Influences

• Moist, unstable air crept closer to the center of
  the surface low during the period of 1200 UTC 09
  November 1998 to 1200 UTC 10 November 1998
  (period of rapid development).
• During this time, the central pressure of the
  cyclone went from 996 mb to 972 mb.
• 24 mb drop in 24 hours Bombogenesis.
• Cyclones rarely bomb out over land.
• Many ingredients came together in the right
  place, at the right time.

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P-S Adiabatic InfluencesEta Dewpoint Analysis
for 11/09/98 1200 UTC
8 C Dewpoint ahead of developing cyclone.

• L

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P-S ADIABATIC INFLUENCESEta Dewpoint Analysis
for 11/10/98 1200 UTC
12 C Dewpoint ahead of developing cyclone.

• L

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P-S Diabatic Heating

• Warm surface produces vertical motion and
  cyclonic vorticity
• Warm Moist Surface from Lakes
• Emit radiant energy
• Provide sensible heat
• Provide latent heat

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P-S SUMMARY

• During a 24 hour period (1200 UTC 9-10 November
  1998), the central pressure of the cyclone went
  from 996 mb to 972 mb.
• 24 mb drop in 24 hours Bombogenesis.
• Cyclones rarely bomb out over land.
• Many ingredients came together in the right
  place, at the right time.
• Vorticity Advection patterns
• Thickness Advection patterns
• Moist, unstable air
• Diabatic heating provided by the Great Lakes
• Diabatic heating provided by the Great Lakes
  served to further intensify and deepen the
  cyclone.

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Great Lakes
Superior
Huron
Michigan
Ontario
Saginaw Bay
Erie
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Effects of Great Lakes on Colorado Cyclones

• September - November
• Cyclones Accelerate while crossing the Great
  Lakes Region
• Cyclones Intensify while crossing the Great Lakes
  Region

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Effects of Great Lakes on Colorado Cyclones

• September - November
• Intensify prior to entering and whithin the Great
  Lakes region
• Weaken and decelerate while exiting the region
• Results from Angel Isard 1997 and
  Petterssen, 1957

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Effects of Cyclones on the Lakes

• Making Waves Effect of Wind on Water
• Size of wave depends on
• Wind Speed stronger wind larger waves
• Duration of the Winds Longer Duration larger
  waves
• Fetch Larger stretch of water larger waves

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Effect of Cyclones on Lakes

• Significant Wave Height
• Defined as the average height of the one-third
  highest waves
• Generally what an experienced observer would most
  frequently report
• Wave heights forecasted and recorded are the
  significant wave height.
• SWH is constrained by fetch
• SWH of 26 feet are about as high as waves can
  build on Superior, no matter how strong the wind,
  or how long it blows.
• However..

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Effect of Cyclones on Lakes

• While the significant wave height is generally
  what is observed and recorded, it is very
  important to note that the rare peak waves can be
  as much as twice the significant wave height.
• This would create 50 foot waves on Lake Superior.

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Effects of Cyclone on Great Lake Region

• Lakes Michigan
• 15 20 ft waves
• Lake Superior
• 20 ft waves
• Wider lake forms larger waves

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Effects of Cyclone on Great Lake Region

• SW 69mph wind gusts pushed water from west Lake
  Erie toward New York and Ontario
• Lake Erie - 4ft below normal

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Effects of Cyclone on Great Lake Region

• Seiche - an oscillation of the surface of a
  landlocked body of water (as a lake) that varies
  in period from a few minutes to several hours

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Effects of Cyclone on Great Lake Region

• Saginaw Bay
• Winds pushed 5 feet of water from Saginaw Bay
  into Lake Huron
• Stranded duck hunters walked 3 miles to original
  shoreline

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Effect of Cyclones on Lakes

• Waves in Lake Superior in November 1998 and 1975?
• 1998
• Rock of Ages Lighthouse and other observation
  points reported long periods of gale force winds
  of 34-47 knots, with gusts over 50 knots.
• Likely produced significant wave heights of 20 to
  25 feet

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Effect of Cyclones on Lakes

• 1975
• Sustained east winds of 34-48 knots were
  forecasted for the night of the Fitzgerald
  sinking
• Fitzgerald reported NE 52 knot winds at 100 am
• Soon after, the NWS upgraded the gale warning to
  a storm warning, forecasting NE winds of 48-63
  knots and waves of 8-15 feet.
• At 700 am, the Fitzgerald reported NE winds at
  35 knots and 10 foot waves (intensifying low
  pressure center was over Marquette, MI at this
  time).

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Effects of Cyclones on Lakes

• Waves would eventually play the ultimate role in
  the sinking of the SS Edmund Fitzgerald.

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SS Edmund Fitzgerald

• Specs
• Length 729 feet
• Width 79 feet
• Height 39 feet
• Weight 13,632 tons
• Load Weight 26,116 tons of taconite (iron)

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SS Edmund Fitzgerald

• The Fitzgerald left Superior, WI on November 9,
  1975 while the weather was calm.
• As weather forecasts of northeasterly winds came
  in, the captains of the Fitzgerald and SS Arthur
  M. Anderson decided to change their course.
• A northward course near the Canadian shore would
  protect the ships from waves generated by a large
  fetch.

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SS Edmund Fitzgerald
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SS Edmund Fitzgerald

• However, on the afternoon of the 10th, the winds
  shifted to northwesterly.
• The ships were no longer protected by land.
• Steady winds at 43 knots and waves of 12-16 feet
  were reported by the Anderson.
• Fitzgerald reported damage and a list.

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Effect of Cyclones on Lakes
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Effect of Cyclones on Lakes
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SS Edmund Fitzgerald
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Theories for Fitzgerald Sinking

• Capsizing by large waves
• 10 to 12 feet of water on its deck.
• Continuous flooding via leaking hatches
• Fitzgerald ran into a wave, cargo and water
  rushed forward, driving the ship into the lake.
• Waves picked up the ship by the ends and the ship
  broke in half.

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November 9-10, 1975

• Sank in Lake Superior due to flooding
• Significant wave heights were up to 25 feet

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Sinking of the Edmund Fitzgerald
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Advances Due to Casualty

• A direct result of the sinking of the Edmund
  Fitzgerald was the installation of buoys on the
  Great Lakes.
• In part, the loss of life in the region, 1868 and
  1869, Congress formed a National Weather Service

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Data Available in the Great Lakes Region1975
vs. 1998

• Advances in
• Numerical Weather Prediction
• Observational Data Set
• 1975 no buoys on the Great Lakes
• 1998 3 buoys and 4 automated weather stations on
  Lake Superior (more data points on other Lakes as
  well)
• Remote Sensing
• Radar
• Satellite

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Data Available in the Great Lakes Region1975
vs. 1998

• Advances in Communication between ships and ships
  and shore
• 1975 VHF radio or MF radio telephone
• Any marine warning, statement or forecasts were
  given by the Coast Guard on VHF radio
• Today
• VHF Radio
• FAXback service
• Digital Marine Weather Dissemination System
• NOAA Weather Radio
• Dial-A-Buoy
• Websites and Internet

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References

• Angel, James R., Scott A. Isard. An
  Observational Study of the Influence of the Great
  Lakes on the Speed and Intensity of Passing
  Cyclones. Monthly Weather Review. 125
  2228-2237
• Fortner, Rosanne W., Daniel W. Jax. The Great
  Lakes Triangle. Ohio State University Research
  Foundation, 1985.
• Freighter Images http//www.crh.noaa.gov/mqt/fit
  zgerald
• National Transportation Safety Board Marine
  Accident Report SS Edmund Fitzgerald Sinking in
  Lake Superior. Report Number NTSB-MAR-78-3
• Petterssen, Sverre. Weather Analysis and
  Forecasting, Volume 1, Second Edition. McGraw
  Hil, 1956.
• Sinking of the Edmund Fitzgerald
  http//cimss.ssec.wisc.edu/wxwise/fitz.html
• Storm Warning Advancements in Marine
  Communications and Forecasting (MQT NWS)
  http//www.crh.noaa.gov/mqt/fitzgerald/index.htm
• U.S. Army Corps of Engineers Satellite Image
  http//www.greatlakes.net/gis/maps