The August 9, 2001 Lake Breeze
Severe Weather Event Across New
York and Western New England
Thomas A. Wasula
NOAA/NWS WFO at Albany
Motivation
 CSTAR II Project
– Northeast Warm Season Severe Weather
– Identify the role terrain features and land/water
boundaries (i.e. Great Lakes, Long Island Sound,
Chesapeake Bay, etc.) have on convective
development and evolution
– Several case studies will analyzed and a climatology
will attempt to be developed
– Mesoscale datasets (observational and model)
Contributors to CSTAR II Project
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Thomas Niziol, (MIC) WFO at Buffalo
Bob LaPlante, (SOO) WFO at Cleveland
Steven Zubrick, (SOO) WFO at Sterling
Dr. Lance Bosart, University at Albany
Dr. Daniel Keyer, University at Albany
Warren Snyder, (SOO) WFO at Albany
Data
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Surface and Upper Air Data (SPC)
Soundings from SPC archive
40-km RUC, 80 km ETA grids
Satellite imagery
Radar data (High resolution KENX
Archive Level IV)
Background
August 9, 2001 Event
 A hot and very humid air mass was in place over
NY and New England
 Surface temps ranging from 32˚C to 37˚C
(Syracuse high temp of 100˚F <ASOS>)
 Surface dewpoints 20-25˚C coupled with large
values of surface based CAPE (exceeding 2000
J/kg)
 Numerous reports of straight line wind damage (60
to 80 mph) in the Mohawk Valley and hail to the
size of hen eggs (2 inches or 5.1 cm)
Severe Weather Reports
Storm Reports across Northeast
NY-VT-NH-ME
• 21 Wind Reports
• 2 Hail Reports
9 AUG 2001/1200 UTC 500 hPa Raob Heights, Temps and Isotachs
www.spc.noaa.gov
9 AUG 2001/1200 UTC 850 hPa Raob Heights,
Temps, Dewpoints and Isotachs
www.spc.noaa.gov
9 AUG 2001/1200 UTC 250 hPa Raob Heights, Temps and Isotachs
www.spc.noaa.gov
9 AUG 2001/1200 UTC ALB Sounding
www.spc.noaa.gov
9 AUG 2001/1200 UTC BUF Sounding
www.spc.noaa.gov
10 AUG 2001/0000 UTC BUF Sounding
www.spc.noaa.gov
10 AUG 2001/0000 UTC ALB Sounding
www.spc.noaa.gov
Lake Ontario SST’s
http://marine.rutgers.edu/mrs/sat_data/
SPC1300 UTC and 1630 UTC DAY 1
ETA: 9 August 2001/1200 UTC Initial Analysis
MSLP (hPa) Solid lines and 1000500 (hPa) thickness dashed
500 hPa Heights (dam) solid lines
and Absolute Vorticity (10x-5s-1)
shaded
ETA: 9 August 2001/1200 UTC Initial Analysis
250 hPa Heights (dam) Solid lines
and Isotachs (m s-1) shaded
850 hPa Heights (dam) solid lines,
and Theta-e (K) dashed and
shaded (every 5K)
ETA: 9 AUG 2001/1200 UTC Initial Analysis
500 hPa Vorticity Advection (x10-10
s-1) shaded and Heights (dam)
solid lines
250 hPa Heights (dam) solid lines
and Isotachs (m s-1) shaded
ETA: 9 August 2001/1200 UTC
6-hr and 12-hr Forecasts for
1800 UTC and 0000 UTC
ETA: 9 August 2001/1200 UTC 6-hour Forecast for 18 UTC
MSLP (hPa) Solid lines and 1000500 (hPa) thickness dashed
500 hPa Heights (dam) solid lines
and Absolute Vorticity (10x-5s-1)
shaded
ETA: 9 August 2001/1200 UTC 6-hour Forecast for 18 UTC
250 hPa Heights (dam) Solid lines
and Isotachs (m s-1) shaded
850 hPa Heights (dam) solid lines,
and Theta-e (K) dashed and
shaded (every 5K)
ETA: 9 AUG 2001/1200 UTC 6- hr forecast for 1800 UTC
700 hPa Heights (m) solid lines and
omega (microbars/second); Warm
colors indicate ascent and cool
colors descent
850 hPa Winds (kts), 850500 hPa lapse rates (°C) and
theta-e (K) shaded
ETA: 9 August 2001/1200 UTC 12-hour Forecast for 00 UTC
MSLP (hPa) Solid lines and 1000500 (hPa) thickness dashed
500 hPa Heights (dam) solid lines
and Absolute Vorticity (10x-5s-1)
shaded
ETA: 9 August 2001/1200 UTC 12-hour Forecast for 0000 UTC
250 hPa Heights (dam) Solid lines
and Isotachs (m s-1) shaded
850 hPa Heights (dam) solid lines,
and Theta-e (K) dashed and
shaded (every 5K)
1500 UTC 9 AUG 2001 Surface Analysis
1745 UTC 9 AUG 2001 Visible Satellite
1800 UTC 9 AUG 2001 Surface Analysis
1845 UTC 9 AUG 2001 Visible Satellite
2215 UTC 9 AUG 2001 Visible Satellite
40 km RUC Analyses
9 AUG 2001/1500-2200 UTC
RUC: 9 August 2001/1500 UTC Analysis
2-meter Temps (˚C) Solid lines
shaded 32˚C and greater and 10
meter winds (knots)
2-meter Dewpoints (˚C) and 10
meter winds (knots)
RUC: 9 August 2001/1600 UTC Analysis
2-meter Temps (˚C) Solid lines
shaded 32˚C (every 2)and greater
and 10 meter winds (knots)
2-meter Dewpoints (˚C) and 10
meter winds (knots)
RUC: 9 August 2001/1700 UTC Analysis
2-meter Temps (˚C) Solid lines
shaded 32˚C (every 2)and greater
and 10 meter winds (knots)
2-meter Dewpoints (˚C) and 10
meter winds (knots)
RUC: 9 August 2001/1800 UTC Analysis
2-meter Temps (˚C) Solid lines
shaded 32˚C (every 2)and greater
and 10 meter winds (knots)
2-meter Dewpoints (˚C) and 10
meter winds (knots)
RUC: 9 August 2001/1800 UTC Analysis
MSLP (hPa) Solid lines and 1000500 hPa thickness (dam)
Pressure tendency (mb/hour)
RUC: 9 August 2001/1900 UTC Analysis
2-meter Temps (˚C) Solid lines
shaded 32˚C (every 2)and greater
and 10 meter winds (knots)
2-meter Dewpoints (˚C) and 10
meter winds (knots)
RUC: 9 August 2001/2000 UTC Analysis
2-meter Temps (˚C) Solid lines
shaded 32˚C (every 2)and greater
and 10 meter winds (knots)
2-meter Dewpoints (˚C) and 10
meter winds (knots)
RUC: 9 August 2001/2100 UTC Analysis
2-meter Temps (˚C) Solid lines
shaded 32˚C (every 2)and greater
and 10 meter winds (knots)
2-meter Dewpoints (˚C) and 10
meter winds (knots)
2100 UTC 9 AUG 2001 Surface Analysis
AUG 9 2001 2100 UTC Surface Analysis with Radar and Satellite
www.unisys.com
RUC: 9 August 2001/2200 UTC Analysis
2-meter Temps (˚C) Solid lines
shaded 32˚C (every 2)and greater
and 10 meter winds (knots)
2-meter Dewpoints (˚C) and 10
meter winds (knots)
0000 UTC 10 AUG 2001 Surface Analysis
KENX Radar Analysis Highlights of the
Severe Weather Event across
New York and Western New England
1958 UTC KENX 0.5° Base Reflectivity
2100 UTC KENX 0.5° Base Reflectivity
2142 UTC KENX VIL Product
2141 UTC KENX Comp Ref X-Section
Herkimer Co.
Storm
2146 UTC KENX 0.5° SRM and
MESO Product
2156 UTC KENX COMP REF
2156 UTC KENX Echo Tops
2156 UTC KENX VIL Product
2156 UTC KENX 0.5° Velocity
2156 UTC KENX Comp Ref X-Section
Herkimer Co.
Storm
2202 UTC KENX VIL Product
VIL=80 kg/m^2
2212 UTC KENX 0.5° SRM and
MESO Product
2258 UTC KENX 0.5° Base REF
2258 UTC KENX 0.5° Velocity
0000 UTC KENX 0.5° Base REF
2354 UTC KENX VWP
0057 UTC KENX 0.5° Base Reflectivity
Preliminary Results
 Lake breeze boundary from Lake Ontario sparked
a cluster of well-organized severe thunderstorms,
some of which were supercellular (marginal shear)
 Boundary interacted with a hot, humid and
unstable air mass and continued over a large area
 850 hPa theta-e values advected into central and
eastern NY in excess of 350K
 Surface based CAPE values well in excess of
2000 J/kg (as high as possibly 5000 J/kg) provided
plenty instability and surface dewpoints in excess
of 21°C an incredible amount of moisture
Future Work
 To further explore mesoscale observational
and model data (10-km ETA and 20-km
RUC)
 Create cross-sections of the evolution and
movement of the lake breeze boundary
 To compare this case with other possible
Lake Ontario and Lake Erie cases