Observed inverted V soundings and downstream severe weather in New York and Pennsylvania
22
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, Pa
description
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, Pa. Outline. Motivation Methodology Climatology of inverted V events Major vs. minor events - PowerPoint PPT Presentation
Transcript of Observed inverted V soundings and downstream severe weather in New York and Pennsylvania
Observed inverted V soundings and downstream severe weather in New York
and PennsylvaniaMike Evans
NOAA/NWS Binghamton, NYBarry Lambert
NOAA/NWS State College, Pa
OutlineMotivationMethodologyClimatology of inverted V eventsMajor vs. minor eventsLow CAPE major vs. High CAPE major eventsConclusion
Motivation – August 17, 2007
August 17, 2007 – upper air
August 17, 2007 - radar
Severe Reports24 wind damage reportsDamage was mostly trees downDamage occurred from the Finger Lakes
through northeast PaNo extra staffing!
August 17, 2007
Albany – 00z, August 18 Buffalo – 00z, August 18
April 8, 2010
April 9, 2010 00z – upper air
April 8, 2010 - radar
April 8, 2010 - Severe reports13 wind damage reportsDamage was mostly trees downDamage in southern New York through
northeast PaNo extra staffing!
April 8, 2010 - sounding
MethodologyExamine events from 2005-2010Major events – 20 or more reports in New
York and PennsylvaniaMinor events – 1 to 4 reports in New York
and PennsylvaniaIdentify events that occurred with inverted V
soundings based on a subjective examination of 12z soundings at PIT and BUF and examination of trajectory forecasts
Methodology / Climatology28 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).
Inverted V criteriaDefine 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.
Major vs. Minor Events9 major events – 424 severe reports - 374 severe wind reports (88 percent)14 minor events – 30 severe reports - 22 severe wind reports (73 percent)
Major vs. Minor Events - charts
Major vs. Minor Events - Charts
Major vs. Minor Events - composites
500 mb heights – major events
500 mb heights – minor events
Surface temperatures – major events
Surface temperatures – minor events
Low CAPE vs. High CAPE major events - charts
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 majors
Summary / ConclusionInverted 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
