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Geostationary Lightning Mapper (GLM)

•Near uniform spatial resolution of approximately 10 km.

•Coverage up to 52 deg latitude.

•70-90% flash detection day and night over the Americas and adjacent ocean regions.

• < 20 sec product latency

•Provides additional information about TC intensity changes and of severe weather events.

LIS/OTD Combined Lightning 1997-2005

GLM detects total strikes: in cloud, cloud to cloud, and cloud to ground

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2011 NHC Proving Ground Products

Rapid Intensification Index (RII) Mark DeMaria / John Knaff

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Lightning-Based Tropical Cyclone Rapid Intensification Index (RII)

• Ground-based lightning data used as a proxy for GOES-R GLM

• NHC real-time rapid intensification index (RII)– Input from GFS model, GOES imagery, oceanic heat

content analyses, Reynolds SST, persistence– Discriminant analysis provides probability of max wind

increase of at least 30 kt in 24 hr• Experimental version adds lightning density input– 6 hr storm-relative composites– 2005-2010 developmental sample from WWLLN – Real time in 2011 from WWLLN feed at CIRA

• Last year Vaisala used in real time, which introduced additional source of error

– Text product distributed from CIRA– Analogous to text product for operational RII

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6 hour WWLLN Lightning Strikes -- Hurricane Omar 16 Oct 2008

RII predictors include inner core (0-100 km) and rainband (200-300 km) lightning strike density

Sample Text Output from 2010 product

Lightning-Based RapidIntensification Forecast Algorithm

Hurricane Alex 30 June 2010 00 UTC

Will be available at: ftp://rammftp.cira.colostate.edu/demaria/NHCPG 5

Summary of 2011 RII Changes

• WWLLN used in real time, consistent with developmental sample

• Output will also include rapid weakening probability – Max wind decrease of 20 kt or more in 24 hr– Valid for storms over water