Transcript Warm Season Thunderstorm Patterns Over the New Jersey

Warm Season Thunderstorm Patterns
Over the New Jersey Area
Al Cope
Paul Croft
National Weather Service
Mount Holly, NJ
Kean University
Union, NJ
Purpose/Intent

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Determine Convective Initiation
Identify Patterns & Coverage
Movement, Intensity, Duration
Thunderstorm Characteristics:
 Spatial – Linear, Isolated, Clustered, Scattered, Widespread &
where will they occur?

Temporal – When will they occur? Continuous in time? How
long will they last?
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Severity – Pulse, Squall, Organized & type of severe weather or
hazard (i.e. tornado, high wind, large hail, heavy rain, lightning)
Topography and Land Use
Surface Characteristics
Topography
Elevation
KMPO
KNYCKLGA
KEWR
KABE
KJFK
KTTN
Surface Character
Elevation (m)
KPHL
Value
-85 - 0
KILG
0 - 52
52 - 99
99 - 145
KACY
145 - 192
192 - 245
0
12.5 25
50
75
´
100
Kilometers
245 - 304
304 - 364
364 - 423
423 - 488
488 - 561
561 - 728
0 10 20
40
60
0 10 20
km
80 40
Null
Open Water
Residential
Commercial
Industrial
Utilities
Barren
Deciduous
Evergreen
Mix Forest
Cropland
Horticulture
Streams, Rivers
Kilometers
60Bays,
80 Estuaries
Data Collection – 2006 & 2007
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Summer data collection at Kean U. and NWS Mount Holly, NJ (Kean students and
student volunteers at NWS PHI)
Daily data collection and archive of radar every three hours (more when warranted)
– mapping of cells/features as well as time and motion
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Maps: Upper Air, Surface Analyses
Numeric Values: Skew-T, Satellite-derived, others
Other Features: Sea breeze, mountain-valley circulations, physiographic features
WRF Modeling (http://hurri.kean.edu/~nwpmodel) – in-house mesoscale model (see
expected evolution from dynamic model perspective)
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“Event” activity initiates after 12 UTC
“Contaminate” activity is ongoing and/or moving into region before 15 UTC
“Non-Event” is null case, no activity observed between 12 and 00 UTC
Methods & Products

Initiate Analysis for determination of spatial and temporal distributional
characteristics and behaviors of convective initiates and the subsequent and
total activity across the study area

Statistical Analysis for determination of convective features and to assess
relationship to synoptic weather patterns, mesoscale circulations, and
physiographic features
Base State Flow at 500mb
Event/Contaminated N NE
June
0,0 0,0
July
0,0 0,0
August
0,0 0,0
Total
E
0,0
0,0
0,0
SE
0,0
0,0
0,0
Frequency Distribution
June
July
Event
4
7
Contaminated
4
3
Total
8
10
S
0,1
0,0
0,0
0,1
SW
4,1
1,1
0,0
5,2
W
0,1
6,2
2,2
8,5
NW
0,1
0,0
0,0
0,1
2006
August Total
2
13
2
9
4
22
Base State Flow at 500mb
Event/Contaminated
N NE
June
2,0 0,0
July
0,0 0,0
August
0,0 0,0
Total
2,0 0,0
E
0,0
0,0
0,0
0,0
Frequency Distribution
June
July
Event
9
10
Contaminated
4
5
Total
13
15
SE
0,0
0,0
0,0
0,0
S
0,1
0,0
0,0
0,1
SW W
1,1 4,1
7,4 2,0
1,0 6,3
9,5 12,4
2007
August Total
7
26
4
13
11
39
NW
0,0
0,1
0,1
0,2
EVENTS - 500 mb West Flow
EVENTS - 500 mb SW Flow
Contaminates – 500mb W & SW Flow
West Flow at 500 mb
Southwest Flow at 500 mb
Initial Results…
Convective Events
Convective Contaminates
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Contaminates do not preclude
further activity with only one
exception
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Contaminates more ‘focused’ cell
areas with W-500mb flow

S/SW flow contaminates mostly
found in southern NJ & coastal
regions
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Seasonal progression appears to
reduce the “source region” of
initiation in NE PA and NW NJ
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Total activity highly variable
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Initiates (W) similar location of
origin to contaminates but they
mostly developed outside NJ;
most total activity isolated
clusters or cells & less “focused”
in comparison to contaminates
June progressing to August
shows just over half initiates have
origin in southern half of study
region versus very little in those
locations during the early summer
Initiates (SW) were found across
study region and were not
constrained to southern NJ (as
were the contaminates)
Activity highly variable, but
limited, in time-placementcoverage versus contaminates
that tended to cluster
Initiates for Events
•Most initiates in NE-PA/NW-NJ
•Trend toward S-NJ later in Summer
Role of Topography?
Sea-breeze Influences
•Favored in July and August
•500mb flow from W and SW
•Often weak/short-lived (not always)
•Generally occurred well inland
Continuing Work…
Collect and analyze data from previous years
Look at severity, lightning, flooding, etc. based on
different regimes
Investigate role of sea breeze, topography, other
meso-scale factors…relate to large-scale
Verify NWS grid/tabular forecasts vs. observed Tstorm activity (Pop, QPF, Weather, Sky…)
Develop conceptual models and and forecast
guidelines for initial activity and evolution
Fin…Ende…Finis…The End
Acknowledgements
Kean Department of Geology & Meteorology
Faculty & Staff, Students and Majors, Alumni
NWS Mount Holly Staff and Student Volunteers
Kean University Meteorology Program
Office of Research & Sponsored Programs
Center for Professional Development
This report was prepared by Kean University and the National Weather Service under a sub-award with
the University Corporation for Atmospheric Research (UCAR) under Cooperative Agreement with the
National Oceanic and Atmospheric Administration (NOAA), U.S. Department of Commerce (DOC).