Joint NWS SOO–NASA SPoRT Workshop Huntsville, Alabama July 2006 Convective (and Lightning) Nowcast Products: SATellite Convection AnalySis and Tracking (SATCAST) System John R. Mecikalski 1 (Assistant Professor) Kristopher M. Bedka 2 Todd A. Berendes 1 Simon J. Paech 1 and Laci Gambill 1 1 Atmospheric Science Department University of Alabama in Huntsville 2 Cooperative Institute for Meteorological Satellite Studies University of Wisconsin-Madison Supported by: NASA New Investigator Program (2002) NASA ASAP Initiative The NASA SPoRT Initiative

Joint NWS SOO–NASA SPoRT Workshop Huntsville, Alabama July 2006 Outline Current capability: Overview Convective initiation (CI) Background Error assessments in Daytime CI 0-1 h Nowcasting Confidence analysis Incorporation of MODIS information Discriminant scoring for CI --> QPE Current & new initiatives: 2006 Impacts of microwave data toward 0-2 hour QPE forecasting Nighttime CI forecasting Lightning (event) & Lightning Initiation forecasting CI/LI Climatology as f(location, time of year) GOES-R Risk Reduction (using MSG & MODIS)

Joint NWS SOO–NASA SPoRT Workshop Huntsville, Alabama July 2006 How this began…

Joint NWS SOO–NASA SPoRT Workshop Huntsville, Alabama July 2006 Methods: Convective Nowcasts/Diagnoses How is this done? Determine the necessary data to evaluate convective and lightning initiation from satellite Is satellite data the best?? If so, how can it be used? Why might it be superior to radar? A: Satellites “see” cumulus before they become thunderstorms! A: There are many available methods for diagnosing/monitoring cumulus motion/development in real-time (every 15-min). See the published research on satellite data usage !!! So, once well-read, all the pieces are in place to move the (science) forward in the CI nowcasting arena, with satellite analysis as the centerpiece for 0-1 h CI nowcasting.

Joint NWS SOO–NASA SPoRT Workshop Huntsville, Alabama July 2006 Where are we now … Applying CI algorithm over U.S., Central America & Caribbean Validation & Confidence analysis Satellite CI climatologies/CI Index: 1-6 h Work with new instruments Data assimilation possibilities

Joint NWS SOO–NASA SPoRT Workshop Huntsville, Alabama July 2006 Build relationships between GOES and NWS WSR-88D imagery: - Identified GOES IR T B and multi-spectral technique thresholds and time trends present before convective storms begin to precipitate - Leveraged upon documented satellite studies of convection/cirrus clouds [Ackerman (1996), Schmetz et al. (1997), Roberts and Rutledge (2003)] - After pre-CI signatures are established, test on other independent cases to assess algorithm performance Use McIDAS to acquire data, generally NOT for processing: GOES-12 1 km visible and 4-8 km infrared imagery every 15 minutes UW-CIMSS visible/IR “Mesoscale” Atmospheric Motion Vectors (AMVs) WSR-88D base reflectivity mosaic used for real-time validation NWP model temperature data for AMV assignment to cumulus cloud pixels … based on relationship between NWP temp profile and cumulus 10.7  m T B Other non-McIDAS data: UAH Convective Cloud Mask to identify locations of cumulus clouds Input Datasets for Convective Nowcasts/Diagnoses

Joint NWS SOO–NASA SPoRT Workshop Huntsville, Alabama July 2006 Convective Cloud Mask Foundation of the CI nowcast algorithm: Calculate IR fields only where cumulus are present (10-30% of a domain) Utilizes a multispectral and textural region clustering technique for classifying all scene types (land, water, stratus/fog, cumulus, cirrus) in a GOES image Identifies 5 types of convectively-induced clouds: low cumulus, mid-level cumulus, deep cumulus, thick cirrus ice cloud/cumulonimbus tops, thin cirrus anvil ice cloud

Joint NWS SOO–NASA SPoRT Workshop Huntsville, Alabama July 2006 “Mesoscale” Atmospheric Motion Vector Algorithm “Operational Settings” New Mesoscale AMVs (only 20% shown) We can combine mesoscale AMV’s with sequences of 10.7  m T B imagery to identify growing convective clouds, which represent a hazard to the aviation community 50% shown

Joint NWS SOO–NASA SPoRT Workshop Huntsville, Alabama July 2006 CI Interest FieldCritical Value 10.7 µm T B (1 score)< 0° C 10.7 µm T B Time Trend (2 scores) < -4° C/15 mins ∆T B /30 mins < ∆T B /15 mins Timing of 10.7 µm T B drop below 0° C (1 score)Within prior 30 mins µm difference (1 score)-35° C to -10° C µm difference (1 score)-25° C to -5° C µm Time Trend (1 score)> 3° C/15 mins µm Time Trend (1 score)> 3° C/15 mins CI Interest Fields for CI Nowcasting from Roberts and Rutledge (2003)

Joint NWS SOO–NASA SPoRT Workshop Huntsville, Alabama July UTC 2030 UTC 2100 UTC CI Nowcast Algorithm: 4 May 2003 Satellite-based CI indicators provided min advanced notice of CI in E. and N. Central Kansas. PODs ~45% at 1 km (FARs ~40%) NEW Linear Discriminant Analysis methods provide ~65% POD scores for 1-hour convective initiation. CI Nowcast Pixels These are 1 hour forecasted CI locations!

Joint NWS SOO–NASA SPoRT Workshop Huntsville, Alabama July 2006 An Example over the Tropics: CI An example of the CI nowcasting method over Central America: Real-time Every 30 min during the day (nighttime coming soon) GOES (MODIS soon) RED/GREEN pixels have highest CI probability

Joint NWS SOO–NASA SPoRT Workshop Huntsville, Alabama July 2006 “Interest Field” Importance: POD/FAR CI Interest FieldCritical Value 10.7 µm T B (1 score)< 0° C 10.7 µm T B Time Trend (2 scores) < -4° C/15 mins ∆T B /30 mins < ∆T B /15 mins Timing of 10.7 µm T B drop below 0° C (1 score)Within prior 30 mins µm difference (1 score)-35° C to -10° C µm difference (1 score)-25° C to -5° C µm Time Trend (1 score)> 3° C/15 mins µm Time Trend (1 score)> 3° C/15 mins Instantaneous 13.3–10.7 um:Highest POD (84%) Time-trend 13.3–10.7 um:Lowest FAR (as low as 38%) Important for CI & Lightning Initiation  m (MODIS) > 0° C  m (MODIS)

Joint NWS SOO–NASA SPoRT Workshop Huntsville, Alabama July 2006 Use of MODIS in Convective Initiation Forecasts

Joint NWS SOO–NASA SPoRT Workshop Huntsville, Alabama July 2006 The lower right shows the supercooled water in green. Proof of concept for determining the difference between supercooled water and glaciated towering cumulus clouds. Super-cooled tops: Lightning indicator as a function of convective environment

Joint NWS SOO–NASA SPoRT Workshop Huntsville, Alabama July 2006 New: CI/LI Linear Discriminant Analysis (LDA) Some correlation between a confidence in CI [f(LDA score)] and 30-min dBZ (increase): QPE nowcast Improved POD of ~65 and FAR of ~34% A virtual-radar from satellite

Joint NWS SOO–NASA SPoRT Workshop Huntsville, Alabama July 2006 New: CI/LI Linear Discriminant Analysis (LDA) Number of Interest Fields Radar dBZ t=t+30 min LDA Score Low correlation High correlation

Joint NWS SOO–NASA SPoRT Workshop Huntsville, Alabama July 2006 Outline Current capability: Overview Convective initiation (CI) Background Error assessments in Daytime CI 0-1 h Nowcasting Confidence analysis Incorporation of MODIS information Discriminant scoring for CI --> QPE Current & new initiatives: 2006 Impacts of microwave data toward 0-2 hour QPE forecasting Nighttime CI forecasting Lightning (event) & Lightning Initiation forecasting CI/LI Climatology as f(location, time of year) GOES-R Risk Reduction (using MSG & MODIS)

Joint NWS SOO–NASA SPoRT Workshop Huntsville, Alabama July 2006 Detecting Convective Initiation at Night Detection of convective initiation at night must address several unique issues: a)Restricted to 4 km data (unless MODIS is relied upon) b)Visible data cannot be used to formulate cumulus mask c)Highly-dense, GOES visible winds are unavailable for tracking d)Forcing for convection often elevated and difficult to detect (e.g., low-level jets, bores, elevated boundaries) However, the advantages are: a)Ability to use ~3.9  m channel (near-infrared) data (!!!) b)More “interest fields” become available for assessing cumulus cloud development Therefore, new work is toward expanding CI detection for nocturnal conditions, and/or where lower resolution may be preferred (i.e. over large oceanic regions). Wayne Mackenzie, MS student

Joint NWS SOO–NASA SPoRT Workshop Huntsville, Alabama July 2006 Detecting Convective Initiation at Night Nighttime CI: Southeast Oklahoma Enhanced 10.7  m SHV: 3:44 UTC

Joint NWS SOO–NASA SPoRT Workshop Huntsville, Alabama July 2006 Detecting Convective Initiation at Night Use of 3.9 µm channel:  m channel difference (Ellrod “fog” product)  m  m Evaluation is being done in light of the forcing for the convection (e.g., low-level jets, QG).

Joint NWS SOO–NASA SPoRT Workshop Huntsville, Alabama July 2006 kkoooooooookkkkkkkkkkk Satellite-Lightning Relationships Current Work: Develop relationships between IR T B /T B trends and lightning source counts/flash densities toward nowcasting (0-2 hr) future lightning occurrence Supported by the NASA New Investigator Program Award #:NAG Incorporate in NWS Lightning Hazard/Prediction Tool 2047 UTC 2147 UTC Northern Alabama LMA Lightning Source Counts UTC UTC

Joint NWS SOO–NASA SPoRT Workshop Huntsville, Alabama July 2006 kkkkkkkkkkkkkkk UTC UTC Northern Alabama LMA Lightning Source Counts Lightning Initiation Potential

Joint NWS SOO–NASA SPoRT Workshop Huntsville, Alabama July 2006 GOES CI Interest Fields: 21 July 2005 (afternoon) CI Climatology Research Details: -topography -main updrafts …for LI 1 km Resolution

Joint NWS SOO–NASA SPoRT Workshop Huntsville, Alabama July 2006 Hyperspectral: GOES-R & GLM LEFT  m Band Difference: Red (  ’s >0) = Ice Comparison between the  m (right) and  m (far right) bands: 22 UTC Small wavenumber change results in significant changes in view:  Low-level water vapor  Surface temperature  Subtle cloud growth & microphysical changes

Joint NWS SOO–NASA SPoRT Workshop Huntsville, Alabama July 2006 For the NWS … Real-time use & evaluation In addition A web-based evaluation is being performed in a post- shift format during July and August Smoothing...

Joint NWS SOO–NASA SPoRT Workshop Huntsville, Alabama July 2006 For the NWS … Real-time use & evaluation

Joint NWS SOO–NASA SPoRT Workshop Huntsville, Alabama July 2006 Contact Information/Publications Contact Info: Prof. John Mecikalski: Kristopher Bedka: Web Pages: nsstc.uah.edu/johnm/ci_home (biscayne.ssec.wisc.edu/~johnm/CI_home/) Publications: Mecikalski, J. R. and K. M. Bedka, 2006: Forecasting convective initiation by monitoring the evolution of moving cumulus in daytime GOES imagery. Mon. Wea. Rev. (IHOP Special Issue, January 2006), 134, Bedka, K. M. and J. R. Mecikalski, 2005: Applications of satellite-derived atmospheric motion vectors for estimating mesoscale flows. J. Appl. Meteor. 44, Mecikalski, J. R., K. M. Bedka, and S. J. Paech, 2006: A statistical evaluation of GOES cloud-top properties for predicting convective initiation. In preparation. Mon. Wea. Rev. Mecikalski, J. R., S. J. Paech, and K. M. Bedka, 2006: Lightning initiation forecasts within the 2-hour timeframe. In preparation. Geophys. Res. Letters.