Mike Evans NOAANWS Binghamton NY Barry Lambert NOAANWS State College Pa Outline Motivation Methodology Climatology of inverted V events Major vs minor events Low CAPE major vs High CAPE major events ID: 407518
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Slide1
Observed inverted V soundings and downstream severe weather in New York and Pennsylvania
Mike Evans
NOAA/NWS Binghamton, NY
Barry Lambert
NOAA/NWS State College, PaSlide2
Outline
Motivation
Methodology
Climatology of inverted V events
Major vs. minor events
Low CAPE major vs. High CAPE major events
ConclusionSlide3
Motivation – August 17, 2007Slide4
August 17, 2007 – upper airSlide5
August 17, 2007 - radarSlide6
Severe Reports
24 wind damage reports
Damage was mostly trees down
Damage occurred from the Finger Lakes through northeast Pa
No extra staffing!Slide7
August 17, 2007
Albany – 00z, August 18
Buffalo – 00z, August 18Slide8
April 8, 2010Slide9
April 9, 2010 00z – upper air Slide10
April 8, 2010 - radarSlide11
April 8, 2010 - Severe reports
13 wind damage reports
Damage was mostly trees down
Damage in southern New York through northeast Pa
No extra staffing! Slide12
April 8, 2010 - soundingSlide13
Methodology
Examine events from 2005-2010
Major events – 20 or more reports in New York and Pennsylvania
Minor events – 1 to 4 reports in New York and Pennsylvania
Identify events that occurred with inverted V soundings based on a subjective examination of 12z soundings at PIT and BUF and examination of trajectory forecastsSlide14
Methodology / Climatology
28 of 79 major events occurred with an upstream inverted V sounding (35 percent).
38 of 140 minor events occurred with an upstream inverted V sounding (27 percent).Slide15
Inverted V criteria
Define a strict criteria for an inverted V sounding:
-
925-800
hPa
lapse rate at least 7.5 C/km
- surface-800
hPa
max
Tdd
greater than 7 C
- 800-500
hPa
min
Tdd
less than 4 C
Result – 9 major events, 14 minor events.
Slide16
Major vs. Minor Events
9 major events – 424 severe reports
- 374 severe wind reports (88 percent)
14 minor events – 30 severe reports
- 22 severe wind reports (73 percent)Slide17
Major vs. Minor Events - chartsSlide18
Major vs. Minor Events - ChartsSlide19
Major vs. Minor Events - composites
500
mb
heights – major events
500
mb
heights – minor events
Surface temperatures – major events
Surface temperatures – minor eventsSlide20
Low CAPE vs. High CAPE major events - chartsSlide21
Low CAPE vs. High CAPE major events - composites
500
mb
heights – low CAPE majors
500
mb
heights – high CAPE majors
Surface temperatures – low CAPE majors
Surface temperatures - high CAPE majorsSlide22
Summary / Conclusion
Inverted V soundings found upstream from approximately 30 percent of major and minor severe weather events
Inverted V events are mostly severe wind producers
Results indicate that sounding and anomaly data can be used to identify major events
Forecasters should take special care to anticipate low CAPE major events