The Variational Version of the Local Analysis and Prediction System (LAPS): Hot-start Data Assimilation of Convective Events Steve Albers, Yuanfu Xie, Hongli Jiang, Dan Birkenheuer, Isidora Jankov, and Zoltan Toth ESRL/GSD WRF Workshop June 26 th 2013 Updated 6/25/ UTC

Presentation Outline LAPS Overview Windsor Tornado Hazardous Weather TestBed (HWT) Future Plans

LAPS System Overview Data Ingest Intermediate data files GSI FORECAST MODEL (e.g. WRF) Verification Analysis Scheme Downscaling can work as a stand alone module from background → GSI or other applications such as Fire wx. Downscaling is also an integral part of variational LAPS (aka. STMAS). Data Background (or cycled forecast) Observations Standalone downscaling module Traditional LAPS Variational LAPS (with downscaling) Model prep

LAPS Motivation High Resolution (500m – 20km), rapid update (10-60min) Highly portable system Collaboration with user community - about 150 world wide  Federal Gov’t – NWS, RSA, PADS, FAA, DHS  State Gov’t – California Dept of Water Resoures  International – Finnish Met. Inst., China Heavy Rain Inst.  Local to Global analysis – used by SOS Wide variety of data sources: OAR/ESRL/GSD/Forecast Applications Branch*

Transition from Traditional to Fully Variational LAPS state vars, wind (u,v) clouds / precip balance and constraints in multi-scale variational analysis Wind analysis Temp/Ht analysis Humidity analysis Cloud analysis balance Traditional LAPS analysis: Wind, Temp, Humidity, Cloud, Balance Ultimately Temporary hybrid system : Traditional LAPS cloud analysis and balance Numerical Forecast model Large Scale Model First Guess Cycling Option Var. LAPS

Cloud Analysis Flow Chart Cloud Fraction 3-D Isosurface * (From radars and model first guess)

Cloud Analysis Independent Validation All-sky Imager Compare LAPS simulated all-sky analyses (or forecasts) to actual all-sky imagery Validates quality of analyses (or forecasts) of clouds / visibility obstructions Courtesy: Longmont Astronomical Society All-Sky Camera Sun Glare

Cloud Analysis Independent Validation All-sky Imager This example has more clouds with high opacity Validation leads to improvements (e.g. parallax correction, thin cirrus) Courtesy: Longmont Astronomical Society Sun Glare

Windsor, CO 2008 Tornado Simulations ModelInitial Conditions Boundary Condition Resolution wrf-wsm6 RUCp 3h fcst + Variational LAPS RUCp+WRF da_update_bc 1.67km (Xie) wrf-tom RUCp 3h fcst + Variational LAPS analysis RUCp + WRF da_update_bc 3km (Jiang)

Windsor mb reflectivity initial= , 1h fcst Mosaic radar vs. WRF forecast (1.67 km res) Analyzed Radar / 10 min Forecast TT

Hazardous Weather Testbed (HWT) Experimental Warning Program (EWP) 2013 Experiment Domains & Fields Forecast: regional domain at 1 km and 3 km resolutions, hourly re-initialization with 15 min model output. Composite Reflectivity CAPE CIN Updraft Helicity Lifted index Satellite simulated IR Brightness Temperature Fractional Cloud Cover Cloud Ceiling Surface analysis: conus domain at 2.5 km resolution available hourly Surface Temperature Dew Point Temperature U,V wind component PMSL surface pressure

Observed & Forecast IR Satellite Brightness Temp HWT 3km Domain 25 Jun Z Simulated VIS also available (derived from cloud amount) Forecasters are naturally familiar with satellite images Used for objective cloud forecast verification OBSForecast

HWT Forecasters’ Input (real time EWP Blog) LAPS again. Higher CAPE, bow echo. Lower CAPE, bye bye bow echo. Posted on May 14, 2013May 14, 2013 “In my opinion, the LAPS surface-based CAPE product was one of the stars of the day. Consistently, storms lived and died based on entering and exiting the tongue of higher CAPE values which extended north and northeast from the Big Bend area for most of the day. This first image shows the LAPS surface-based CAPE at 00Z, and the radar at the same time. Shouldn’t be hard to pick out the storm of interest. Note that the storm is still in the tongue of J/kg of CAPE as noted on LAPS. One hour later, the storm is exiting and entering a less favorable instability regime. And predictably, it starts to weaken Any questions? LAPS nailed it.” CL

Moore Tornado Related Blog Entries LAPS Observations and Determining Future Storm Development… Posted on May 20, 2013May 20, 2013 “Just a quick post about observations of the LAPS theta-e field this afternoon. It was interesting to see the near stationary aspect of the theta-e boundary in assoc/w the dryline to our south across portions of north Texas this afternoon. This suggests that continued development is possible late this afternoon especially across northern Texas, where the gradients have been sustained and have even increased lately. However, notice that the gradients have decreased generally across much of Oklahoma where convection and related effects (rain cooled air, cloud shield) have helped to stabilize the environment. The 15-minute temporal resolution of the product can be very useful for diagnosing locations of continued convection especially in rapidly developing convective situations.” 2115UTC 2130UTC 2145UTC 2200UTC LAPS analysis. Shaded values are sfc theta-e (K), while wind vectors are in blue. LAPS niche: Good handle on existing convection and lead time on CI

HWT 1km V-LAPS 0-3 h Composite Reflectivity Verification Higher ETS (best at short lead time) Compare WRF initialization schemes, work with DTC? Var. LAPS Initialization

Moore Tornado 1hr LAPS Forecast

Simulated IR Satellite Forecast * Simulated IR Satellite LAPS / WRF 6-Hr Forecast Verification Forecast high clouds sometimes look too thick

Future Plans - Cloud Analysis Develop and validate forward models and their adjoints for all data sources being used to more fully implement a variational approach Utilize improved constraints relating various control and derived variables Combine ensemble background error covariances into multiscale variational analysis, i.e., different scale error covariances applied at different multigrid levels of the variational LAPS analysis OAR/ESRL/GSD/Forecast Applications Branch *

Cloud Forecast Plans Improve Hot-Start Elements o Hydrometeors, Temperature, Water Vapor, Vert-Vel Examine various WRF radiation options and their consistency with microphysics Consider water vapor given small-scale / partial clouds in a grid-box Combine with analysis for 4DVAR OAR/ESRL/GSD/Forecast Applications Branch*

ExREF – Experimental Regional Ensemble Forecasting System Experimental GSD: Realtime runs & develop HMT: Extreme pcp guidance DTC: Evaluation WPC: Flash Flood Experiment EMC: test methods for SREF 9-km grid 4xday to 84 h Results on web, ftp, LDM Diversity GFS and LAPS initialization (traditional & variational) GEFS boundary conditions Multiple microphysics See Posters 49 by Bernardet et al. 50 by Jankov et al.