111 National Aeronautics and Space Administration Science Mission Directorate Earth-Sun System Division Short-term Forecasting and WRF Case Study Steven J. Goodman W. Lapenta, K. La Casse, E. McCaul, and W. Petersen NASA Marshall Space Flight Center Earth and Planetary Science Branch Huntsville, Alabama, USA NWS Severe Weather Technology Workshop July 2005 Silver Spring, MD

222 National Aeronautics and Space Administration Science Mission Directorate Earth-Sun System Division Outline of Talk 1.Nowcasting Gaps and Opportunities 2.WRF-RAMS Case Study- 10 Dec Columbia Project-WRF modeling plans 4.Concluding Remarks

333 National Aeronautics and Space Administration Science Mission Directorate Earth-Sun System Division ThemeService GapSolutionImpact Severe Weather Specification of pre-storm environment, boundaries, severe WX signatures WRF, DA, ensembles, lightning data, SCAN, higher res. satellite obs. Improved POD, lead- time, FAR, more precise boundary observations Aviation Weather Timing and location of convection, probabilistic information for DSS WRF, ensembles, DA, hourly updates, NCWF (radar + lightning) 50% increase POD, greater operational utility NWS STIP Solutions (Science and Technology Infusion Plan) Weather Research and Forecast, WRF Data Assimilation, DA Additional Forecast Interests CI- convective initiation TI- first lightning (35 dbZ at -15C) TF- final lightning

444 National Aeronautics and Space Administration Science Mission Directorate Earth-Sun System Division *Visionary Forecast and Warning Lead Times Variable (Lead Time) Tornado12 min1 hr Severe Storm18 min (county)4 hr (city) Flash flood43 min (county)4 hr (neighborhood) Hurricane 20 hr/400 mi (coastline) 3 days/200 mi (coastline) Winter storm9 hr (county) 5 days (neighborhood) Low ceiling, visibility-5 hr (airport, port) Turbulence, icing`- 5 hr along flight corridor Maritime wind, wave-5 hr Air Quality(city)5 days * NWS Science and Technology Infusion Plan: Lightning Observation and Forecast Benefit

555 National Aeronautics and Space Administration Science Mission Directorate Earth-Sun System Division Nowcasting Defined Nowcasting: forecasting with local detail, by any method, over a period from the present to a few hours ahead; that includes a detailed description of the present weather, and includes the blending of extrapolation, statistical, and heuristic techniques (includes theory, expert systems, fuzzy logic, and forecaster rule of thumb), and NWP

Forecast rules e.q boundary collision storm initiation likely Data Fusion System ExtrapolationStatistical Radar retrievals Convergence line Detection & characterization Model derived forecast fields NWP Forecaster Input e.q. convergence line Input, meteorological situation Nowcast Forecast Rules Courtesy, Jim Wilson NCAR WWRP/Tom Keenan

777 National Aeronautics and Space Administration Science Mission Directorate Earth-Sun System Division Lightning Connection to Thunderstorm Updraft, Storm Growth and Decay Total Lightning —responds to updraft velocity and concentration, phase, type of hydrometeors, integrated flux of particles WX Radar — responds to concentration, size, phase, and type of hydrometeors- integrated over small volumes Microwave Radiometer — responds to concentration, size, phase, and type of hydrometeors — integrated over depth of storm (85 GHz ice scattering) VIS / IR — cloud top height/temperature, texture, optical depth

888 National Aeronautics and Space Administration Science Mission Directorate Earth-Sun System Division WRF Configuration 4km horizontal resolution 37 vertical levels Dynamics and physics –Eulerian mass core –Dudhia SW radiation –RRTM LW radiation –YSU PBL scheme –Noah LSM –WSM 6-class microphysics scheme –Explicit convection 24h forecast initialized at 00 UTC 10 December 2004 with AWIP212 NCEP EDAS analysis Eta 3-h forecasts used for LBC’s Cloud cover 18h forecast valid at 18 UTC 10 Dec. 2004

999 National Aeronautics and Space Administration Science Mission Directorate Earth-Sun System Division WRF Surface Based CAPE 18h fcst valid 18 UTC Dec 10

10 National Aeronautics and Space Administration Science Mission Directorate Earth-Sun System Division WRF Sounding ~ 800 J/kg CAPE

11 National Aeronautics and Space Administration Science Mission Directorate Earth-Sun System Division MIPS Sounding ~ 761 J/kg CAPE Low level lapse rates and low freezing level efficient for converting CAPE to kinetic energy Surface T=15C, Td=10C Max w= 19 m/s UAH MIPS, Kevin Knupp

12 National Aeronautics and Space Administration Science Mission Directorate Earth-Sun System Division WRF 3h Precipitation 18h fcst valid 18 UTC Dec 10

13 National Aeronautics and Space Administration Science Mission Directorate Earth-Sun System Division WRF 3h Precipitation 21h fcst valid 21 UTC Dec 10

14 National Aeronautics and Space Administration Science Mission Directorate Earth-Sun System Division WRF 3h Precipitation 21h fcst valid 21 UTC Dec 10 Question: Any lightning, when was it, What was WRF reflectivity at -15 C?

15 National Aeronautics and Space Administration Science Mission Directorate Earth-Sun System Division WRF Reflectivity (dBZ) 18h forecast valid at 18 UTC 10 Dec hPa -15 C - 0 C - WRF reflectivity cores too shallow

16 National Aeronautics and Space Administration Science Mission Directorate Earth-Sun System Division Reflectivity (dBZ) 06:50h forecast valid at 18:50 UTC 10 Dec hPa

17 National Aeronautics and Space Administration Science Mission Directorate Earth-Sun System Division Ground-truth Report of Dime-Size Hail Owens Crossroads, Alabama

18 National Aeronautics and Space Administration Science Mission Directorate Earth-Sun System Division 10 December Hail Case ARMOR collected data! First time ZDR used on television! Cold upper-low GOES 2057 J/kg CAPE in a layer about 7.5 km deep GOES sounding too warm and moist near surface, likely cloud contaminated Dime to quarter-sized hail reported in SE Madison county and in S. Tennessee

19 National Aeronautics and Space Administration Science Mission Directorate Earth-Sun System Division KHTX NEXRAD

20 National Aeronautics and Space Administration Science Mission Directorate Earth-Sun System Division ARMOR 1.3 degree PPI scan at 17:55 UTC on 10 Dec. 04 NCAR HYDRO-IDREFLECTIVITY Drizzle Lt. Rain Mod. Rain Heavy Rain Hail Hail/Rain Small Hail Rain/Sm. Hail Dry Snow Wet Snow Cloud Ice Crys. HAILRAINSMALL HAIL Particle IdentificationReflectivity [dBZ]

21 National Aeronautics and Space Administration Science Mission Directorate Earth-Sun System Division dBZ ZDR ARMOR: 12/10/04 17:55:06 EL=1.3 o Rain 55+ dBZ Hail 55+ dBZ Rain 2 to 3.5 dB Hail -1 to 0.5 dB Hail -1.5 to 0.5 dB Rain/Hail -0.5 to 2 dB Rain/Hail dBZ Hail dBZ At 17:55 IC fl. rate ~ 3/minute in southern cell No IC’s in northern cell at 17:55 No CG’s in either cell for 20 minutes centered on 17:55 Only 3 CG’s detected for duration of storms LMA S. Cell 17:52:30 – 17:57:30

22 National Aeronautics and Space Administration Science Mission Directorate Earth-Sun System Division LMA Observed Flashes Precede Hail Report

23 National Aeronautics and Space Administration Science Mission Directorate Earth-Sun System Division RAMS Configuration 500 m horizontal resolution Height  z is variable, from 250 m at bottom to 750 m at 20 km height Domain 75 km x 75 km x 24.5 km Time,  t = 4 s, five acoustic steps between Smagorinsky subgrid mixing scheme 5-class precipitating hydrometeors: –Rain, snow, aggregates, graupel, hail Initialized with 3K warm bubble, radius=12 km at z=0 120 min simulation, initiation effects dominate until t=60 min

24 National Aeronautics and Space Administration Science Mission Directorate Earth-Sun System Division RAMS Configuration 500 m horizontal resolution Height  z is variable, from 250 m at bottom to 750 m at 20 km height Domain 75 km x 75 km x 24.5 km Time,  t = 4 s, five acoustic steps between Smagorinsky subgrid mixing scheme 5-class precipitating hydrometeors: –Rain, snow, aggregates, graupel, hail Initialized with 3K warm bubble, radius=12 km at z=0 120 min simulation, initiation effects dominate until t=60 min Graupel

25 National Aeronautics and Space Administration Science Mission Directorate Earth-Sun System Division RAMS Configuration 500 m horizontal resolution Height  z is variable, from 250 m at bottom to 750 m at 20 km height Domain 75 km x 75 km x 24.5 km Time,  t = 4 s, five acoustic steps between Smagorinsky subgrid mixing scheme 5-class precipitating hydrometeors: –Rain, snow, aggregates, graupel, hail Initialized with 3K warm bubble, radius=12 km at z=0 120 min simulation, initiation effects dominate until t=60 min Hail

26 National Aeronautics and Space Administration Science Mission Directorate Earth-Sun System Division Objective of Columbia Usage Enables experimental high-resolution atmospheric modeling at 2 km resolution on an operational basis that would not be possible otherwise Unique computational resources allows compilation of results for more than a single season Allows for subjective impact assessment from operational NWS forecast community PI: William M. Lapenta/NASA Short-term Prediction Research and Transition MSFC Co-Is/Partners Kate La Casse and Stephanie Haines, University of Alabama in Huntsville Gary Jedlovec, MSFC; Scott Dembek (USRA) Steven Lazarus, Florida Institute of Technology Identify the codes to be run on Columbia Scientific Impact Hypothesis: Accurate specification of the lower-boundary forcing (i.e., the specification of localized SST gradients and anomalies) within the WRF prediction system will result in improved land/sea fluxes and hence, more accurate evolution of coastal mesoscale circulations and the sensible weather elements (i.e., low-level horizontal transport, temperature trends, clouds, and precipitation) associated with them. WRF: Weather Prediction Model ADAS: Data Assimilation System Science Mission Directorate - Project Columbia Investigation 100,000 Processor Hours awarded March 2005 Award number: SMD-Dec Key Milestones Implement and optimize WRF configuration 05/05 Develop Web-based visualization for model output 05/05 Conduct simulations on a daily basis 06/05 Provide output to FL NWSFO’s in AWIPS 07/05 Preliminary MODIS SST impact assessment 10/05 Present results at AMS Annual Meeting 01/06 Prepare manuscript for peer-review publication 03/06 Report findings to WRF modeling community 03/06 Use of MODIS SST to Improve High Resolution Modeling of Atmosphere/Ocean Interactions within the Gulf of Mexico and Florida Coastal Zones Sea surface temperature fields (K) mapped to a numerical model 2 km grid near Cape Canaveral, FL. The RTG is a default field used in most models. The MODIS SST composite contains detailed spatial structure that is known to affect weather near and along coastlines associated with mesoscale circulations.

27 National Aeronautics and Space Administration Science Mission Directorate Earth-Sun System Division Motivation for using High-Resolution MODIS SST Fields in NWP Models  SST known to influence coastal mesoscale processes  Can impact warm-season precipitation distribution  Sea breeze circulations important to heavily populated areas (HOU, NYC)  Strong influence on height of marine boundary layer cool warm

28 National Aeronautics and Space Administration Science Mission Directorate Earth-Sun System Division Use of High-Resolution MODIS SST Fields in NWP Models  SST known to influence coastal mesoscale processes  Can impact warm-season precipitation distribution  Sea breeze circulations important to heavily populated areas (HOU, NYC)  Strong influence on height of marine boundary layer cool warm MODIS – RTG (°C) Mapped to MM5 2km grid °C °C

29 National Aeronautics and Space Administration Science Mission Directorate Earth-Sun System Division WRF vs Eta Forecast, 14 July 2005

30 National Aeronautics and Space Administration Science Mission Directorate Earth-Sun System Division NLDN Observed Lightning, 14 July 2005