the tc tornado database at spc background, summary and analyses

The TC Tornado Database at SPC

Background, Summary and AnalysesBackground, Summary and Analyses

WHY COMPILED

• No “standardized” TC tornado database

• NOAA/NWS/SPC is logical source

• Need for consistent data for scientific and risk analysis

• Minimize climatological “shocks” (secular influences)

• Database should be flexible:

UPDATABLE: Add new events each year

AMENDABLE: Change historical records as new information comes in or errors are uncovered

DISCLAIMER: Analytic results may change as added/changed data occur

HOW COMPILED

• SPC “ONETOR” WHOLE-TORNADO DATA

Stitched together NCDC county-segments

1139 events in 1995-2008 (none in 2009, 2010 not in yet), will update yearly

Manually parsed TC tornadoes: analytically, no threshold radii or other inflexible criteria

• HURRDAT for TORNADO TIME

TC position interpolated from 6-hourly lat/lon

TC motion based on vector between last and next 6-hourly best-track positions

TC intensity is last 6-hourly OFCL

HOW COMPILED

• IF NO HURRDAT (POST-CLASSIFICATION)

Rare (<1%) of TC tornadoes

TC remnant position and intensity: Used hourly sfc maps (via SPC archives or Plymouth State)

Must still have closed low

• BASIC ANALYSES PROVIDED in TCTOR

Interpolated TC position/motion

Tornado AZRAN from interpolated center

Tornadoes per TC and per year

SOME ANALYTIC RESULTS

Geography of TCTOR Geography of TCTOR eventsevents

SOME ANALYTIC RESULTS

TCTOR Summary by YearTCTOR Summary by Year

SOME ANALYTIC RESULTS

SOME ANALYTIC RESULTS

Tornadic TC strength and Tornadic TC strength and ranksranks

SOME ANALYTIC RESULTS

AZRAN of TCTOR events from AZRAN of TCTOR events from centercenter

SOME ANALYTIC RESULTS

Motion-relative AZRAN Motion-relative AZRAN of TCTOR events from of TCTOR events from center: center: Northward Northward translation componenttranslation component

Motion-relative AZRAN Motion-relative AZRAN of TCTOR events from of TCTOR events from center: center: Southward Southward translation componenttranslation component

SOME ANALYTIC RESULTS

CartesiaCartesian:ALL n:ALL

CartesiaCartesian:TS n:TS

CartesiaCartesian:Hurricn:Hurricanes anes

CartesiaCartesian:n:<< TD TD

SOME ANALYTIC RESULTS

AZRANs for AZRANs for IVANIVAN

Distribution Distribution by damage by damage ratingrating

Convective modes for tornado cases Convective modes for tornado cases 2003-20082003-2008

Edwards et al. 2010

Assessed case-by-case for 664 GRIDDED and FILTERED tornadoes

238 DISCRETE SUPERCELLS (36%)

232 SUPERCELLS-IN-CLUSTERS (35%)

64 SUPERCELLS-IN-LINES (10%)

53 MARGINAL “PSEUDOCELLS” (8%)

77 NONSUPERCELLS OF ALL MODES (12%)

(These were broken down by mode…small samples)

APPLIED ANALYSES

MODE EXAMPLE: Discrete Supercell MODE EXAMPLE: Discrete Supercell (Ivan-04)(Ivan-04)

Edwards et al. 2010

APPLIED ANALYSES

MODE EXAMPLE: Nonsupercell in Cluster MODE EXAMPLE: Nonsupercell in Cluster (Arlene-05)(Arlene-05)

Edwards et al. 2010

APPLIED ANALYSES

MODE EXAMPLE: MRGL in Line (Gustav-08)MODE EXAMPLE: MRGL in Line (Gustav-08)

Edwards et al. 2010

APPLIED ANALYSES

Edwards et al. 2010

APPLIED ANALYSES

Supercells in Supercells in general, general, discretediscrete ones in particular, ones in particular, represent greatest represent greatest

risk for risk for SIGNIFICANT TC SIGNIFICANT TC

tornadoes.tornadoes.

Edwards et al. 2010

APPLIED ANALYSES

MESOCYCLONE CLASSES by MODEMESOCYCLONE CLASSES by MODE

Edwards et al. 2010

APPLIED ANALYSES

Environments of tornadic TC cells Environments of tornadic TC cells 2003-20082003-2008

Edwards et al. 2010

BASED ON 2003-2008 SPC GRIDDED RUC-“SFCOA” DATASET

NUMEROUS PARAMETERS DERIVED FROM RECONSTITUTED GRIDPOINT SOUNDINGS

TC TORNADO ENVIRONMENTS ANALYZED IN BULK

TC TORNADO ENVIRONMENTS ANALYZED BY CONVECTIVE MODE

TC AND NON-TC TORNADO ENVIRONMENTS COMPARED TO EACH OTHER

MESOCYCLONE STRENGTH FOR SUPERCELLS

APPLIED ANALYSES

ENVIRONMENTAL ANALYSISENVIRONMENTAL ANALYSIS

Edwards et al. 2010

APPLIED ANALYSES

DATABASE ONLINE: www.spc.noaa.gov/www.spc.noaa.gov/

misc / edwards / TCTOR / TCTOR.xls

misc / edwards / TCTOR / readme.txtDOCUMENTATION:

www.spc.noaa.gov/publications

Contact: Roger.Edwards@noaa.gov

SPC CALL FOR INPUT

In differentiating organized southeastern pulse/multicell

severe environments