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2005 SPoRT SAC Review Huntsville, AL, 21-22 November 2005 Convective Initiation: Short-term Prediction and Climatology Research John R. Mecikalski 1, Kristopher.

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Presentation on theme: "2005 SPoRT SAC Review Huntsville, AL, 21-22 November 2005 Convective Initiation: Short-term Prediction and Climatology Research John R. Mecikalski 1, Kristopher."— Presentation transcript:

1 2005 SPoRT SAC Review Huntsville, AL, 21-22 November 2005 Convective Initiation: Short-term Prediction and Climatology Research John R. Mecikalski 1, Kristopher M. Bedka 2 Simon J. Paech 1, Todd A. Berendes 1, Wayne M. Mackenzie 1, 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: The NASA SPoRT Initiative NASA New Investigator Program (2002)

2 2005 SPoRT SAC Review Huntsville, AL, 21-22 November 2005 Overview: UAH Contributions Diagnostics: ALEXI land-surface (S o, A w, R net, ET) fields, ADAS surface T a. All at 2-10 km resolution. Aviation Safety. Nowcasting (0-6 h): Convective initiation (CI), Lightning Initiation & First Lightning; “CI Index” for 2-6 h CI (based on satellite & NWP model fields). Aviation Safety (ASAP). Short-term Prediction (6-24 h): Utilize “diagnostics” as satellite-based boundary conditions, ADAS populated by remote sensing data (satellite & radar) toward a high-resolution (5-10 km) regional initialization for ARPS, WRF, etc. UAH Graduate students: NWS SCEP, MS/Ph.D. studies that involve NWS interactions. Developing “in-house” nowcasting expertise.

3 2005 SPoRT SAC Review Huntsville, AL, 21-22 November 2005 Overview: UAH Contributions Diagnostics: ALEXI land-surface (S o, A w, R net, ET) fields, ADAS surface T a. All at 2-10 km resolution. Nowcasting (0-6 h): Convective initiation (CI), Lightning Initiation & First Lightning; “CI Index” for 2-6 h CI (based on satellite & NWP model fields). Aviation Safety (ASAP). Short-term Prediction (6-24 h): Utilize “diagnostics” as satellite-based boundary conditions, ADAS populated by remote sensing data (satellite & radar) toward a high-resolution (5-10 km) regional initialization for ARPS, WRF, etc. UAH Graduate students: NWS SCEP, MS/Ph.D. studies that involve NWS interactions. Developing “in-house” nowcasting expertise.

4 2005 SPoRT SAC Review Huntsville, AL, 21-22 November 2005 Outline Current capability: Overview Background Error assessments Confidence analysis Incorporation of MODIS information Current & new initiatives for SPoRT in 2006 NWS transition and assessment Nighttime CI forecasting Lightning (event) forecasting

5 2005 SPoRT SAC Review Huntsville, AL, 21-22 November 2005 How this began… Which cumulus will become a thunderstorm? GEO satellite seems to be well-suited to address this question. What methods are available? What changes to current, globally-developed codes are needed?  Who can benefit from this research?  What user groups are interested (e.g., 0-2 h nowcasting)

6 2005 SPoRT SAC Review Huntsville, AL, 21-22 November 2005 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

7 2005 SPoRT SAC Review Huntsville, AL, 21-22 November 2005 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

8 2005 SPoRT SAC Review Huntsville, AL, 21-22 November 2005 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

9 2005 SPoRT SAC Review Huntsville, AL, 21-22 November 2005 “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

10 2005 SPoRT SAC Review Huntsville, AL, 21-22 November 2005 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 6.5 - 10.7 µm difference (1 score)-35° C to -10° C 13.3 - 10.7 µm difference (1 score)-25° C to -5° C 6.5 - 10.7 µm Time Trend (1 score)> 3° C/15 mins 13.3 - 10.7 µm Time Trend (1 score)> 3° C/15 mins CI Interest Fields for CI Nowcasting from Roberts and Rutledge (2003)

11 2005 SPoRT SAC Review Huntsville, AL, 21-22 November 2005 2000 UTC 2030 UTC 2100 UTC CI Nowcast Algorithm: 4 May 2003 Satellite-based CI indicators provided 30-45 min advanced notice of CI in E. and N. Central Kansas. PODs ~50% 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!

12 2005 SPoRT SAC Review Huntsville, AL, 21-22 November 2005 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

13 2005 SPoRT SAC Review Huntsville, AL, 21-22 November 2005 CI “Interest Fields”: 8-GOES 2-MODIS 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 6.5 - 10.7 µm difference (1 score)-35° C to -10° C 13.3 - 10.7 µm difference (1 score)-25° C to -5° C 6.5 - 10.7 µm Time Trend (1 score)> 3° C/15 mins 13.3 - 10.7 µm Time Trend (1 score)> 3° C/15 mins 8.5-10.7  m (MODIS) > 0° C

14 2005 SPoRT SAC Review Huntsville, AL, 21-22 November 2005 “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 6.5 - 10.7 µm difference (1 score)-35° C to -10° C 13.3 - 10.7 µm difference (1 score)-25° C to -5° C 6.5 - 10.7 µm Time Trend (1 score)> 3° C/15 mins 13.3 - 10.7 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 8.5-10.7  m (MODIS) > 0° C

15 2005 SPoRT SAC Review Huntsville, AL, 21-22 November 2005 Use of MODIS in Convective Initiation Forecasts MODIS 3.7-11.0  mMODIS 8.5-11.0  m Smaller ice particles/ higher numbers 00

16 2005 SPoRT SAC Review Huntsville, AL, 21-22 November 2005

17 2005 SPoRT SAC Review Huntsville, AL, 21-22 November 2005 The lower right shows the supercooled water in green. Proof of concept for determining the difference between supercooled water and glaciated towering cumulus clouds.

18 2005 SPoRT SAC Review Huntsville, AL, 21-22 November 2005 ddddddddddddddddddddddd 1)Remap GOES data to 1 km gridded radar reflectivity data Correct for parallax effect by obtaining cloud height through matching the 10.7  m T B to standard atmospheric T profile 2)Identify radar/lightning pixels that have undergone CI/LI at t+30 mins Advect pixels forward using low-level satellite wind field to find their approximate location 30 mins later 3)Determine what has occurred between imagery at time t, t-15, & t-30 mins to force CI/LI to occur in the future (t+30 mins) 4)Collect database of IR interest fields (IFs) for these CI/LI pixels 5)Apply LDA: identify relative contribution of each IF toward an accurate nowcast Test LDA equation on independent cases to assess skill of new method CI/LI Linear Discriminant Analysis (LDA)

19 2005 SPoRT SAC Review Huntsville, AL, 21-22 November 2005 CI/LI Linear Discriminant Analysis (LDA) Improved POD of ~65% and FAR of ~34% A virtual-radar from satellite

20 2005 SPoRT SAC Review Huntsville, AL, 21-22 November 2005 Outline Current capability: Overview Background Error assessments Confidence analysis Incorporation of MODIS information Current & new initiatives for SPoRT in 2006 NWS transition and assessment Nighttime CI forecasting Lightning (event) forecasting

21 2005 SPoRT SAC Review Huntsville, AL, 21-22 November 2005 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

22 2005 SPoRT SAC Review Huntsville, AL, 21-22 November 2005 Detecting Convective Initiation at Night Nighttime CI: Southeast Oklahoma Enhanced 10.7  m SHV: 2:57 - 3:44 UTC

23 2005 SPoRT SAC Review Huntsville, AL, 21-22 November 2005 Detecting Convective Initiation at Night What we’ve learned so far: 10.7-3.9  m channel difference (Ellrod “fog” product) 13.3-3.9  m 6.5-3.9  m Evaluation is being done in light of the forcing for the convection (e.g., low-level jets, QG).

24 2005 SPoRT SAC Review Huntsville, AL, 21-22 November 2005 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 #:NAG5-12536 2047 UTC 2147 UTC Northern Alabama LMA Lightning Source Counts 2040-2050 UTC 2140-2150 UTC

25 2005 SPoRT SAC Review Huntsville, AL, 21-22 November 2005 The Meteosat Second Generation (MSG) satellite system could be used effectively for CI nowcasting within this algorithm: 12 spectral bands; ~3 km resolution, 2 water vapor channels centered on two different central wavelengths. 8.7 µm, 9.7 µm, ~1.5 µm channels Plus many of the GOES capabilities. Meteosat Second Generation (MSG) Nighttime CI event over Italy 9.7 µm 8.7 µm

26 2005 SPoRT SAC Review Huntsville, AL, 21-22 November 2005 Transition Activities NWSFO Huntsville (May 2005) NOAA WWB (September 2005) FAA AWRP (Spring 2005) FAA MIT-LL (now) AWIPS

27 2005 SPoRT SAC Review Huntsville, AL, 21-22 November 2005 Theme 1: Formal NWS evaluation of 0-1 hour CI product (that has been pushed to NWS Huntsville since May 2005). Theme 2: First efforts at 30-min to 1.5 hour lightning initiation nowcasting. Theme 3: Formation of “CI Index” that is based on Climatology of CI fields over Southeastern U.S., NWSFO region, etc. Theme 4: First developments of assimilation of “boundaries” as defined by CI fields. Nowcasting plans for 2006

28 2005 SPoRT SAC Review Huntsville, AL, 21-22 November 2005 Contact Information/Publications Contact Info: Prof. John Mecikalski: johnm@nsstc.uah.edu Kristopher Bedka: krisb@ssec.wisc.edu Web Pages: nsstc.uah.edu/johnm/ci_home (biscayne.ssec.wisc.edu/~johnm/CI_home/) http://www.ssec.wisc.edu/asap Publications: Mecikalski, J. R. and K. M. Bedka, 2006: Forecasting convective initiation by monitoring the evolution of moving cumulus in daytime GOES imagery. In Press. Mon. Wea. Rev. (IHOP Special Issue, January 2006). Bedka, K. M. and J. R. Mecikalski, 2005: Applications of satellite-derived atmospheric motion vectors for estimating mesoscale flows. J. Appl. Meteor. 44, 1761-1772. Mecikalski, J. R., K. M. Bedka, and S. J. Paech, 2005: A statistical evaluation of GOES cloud-top properties for predicting convective initiation. In preparation. Mon. Wea. Rev. 6-conference talks/posters in 2005/06


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