# Presentation: 833783

## Short-term Forecasting

**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
- 12-14 July 2005
- Silver Spring, MD

## Outline of Talk

**Outline of Talk**
**Nowcasting Gaps and Opportunities**
**WRF-RAMS Case Study- 10 Dec. 2004**
**Columbia Project-WRF modeling plans**
**Concluding Remarks**

## NWS STIP Solutions

| Theme | Service Gap | Solution | Impact |
| --- | --- | --- | --- |
| 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

## *Visionary Forecast and Warning Lead Times

***Visionary Forecast and Warning Lead Times**

| Variable
(Lead Time) | 2000 | 2012 |
| --- | --- | --- |
| Tornado | 12 min | 1 hr |
| Severe Storm | 18 min (county) | 4 hr (city) |
| Flash flood | 43 min (county) | 4 hr (neighborhood) |
| Hurricane | 20 hr/400 mi (coastline) | 3 days/200 mi (coastline) |
| Winter storm | 9 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

## 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

## WWRP/Tom Keenan

## 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

## 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

## WRF Surface Based CAPE

**WRF Surface Based CAPE**
**18h fcst valid 18 UTC Dec 10**

## WRF Sounding ~ 800 J/kg CAPE

**WRF Sounding ~ 800 J/kg CAPE**

## 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

## WRF 3h Precipitation

**WRF 3h Precipitation**
**18h fcst valid 18 UTC Dec 10**

## WRF 3h Precipitation

**WRF 3h Precipitation**
**21h fcst valid 21 UTC Dec 10**

## WRF 3h Precipitation

**WRF 3h Precipitation**
**21h fcst valid 21 UTC Dec 10**

- _Question_: Any lightning, when was it,
- What was WRF reflectivity at -15 C?

## WRF Reflectivity (dBZ)18h forecast valid at 18 UTC 10 Dec. 2004

**WRF Reflectivity (dBZ)****18h forecast valid at 18 UTC 10 Dec. 2004**

- 850 hPa

- -15 C -

-  0 C -

- WRF reflectivity cores too shallow

## Reflectivity (dBZ)06:50h forecast valid at 18:50 UTC 10 Dec. 2004

## Ground-truth Report of Dime-Size Hail

- Owens Crossroads, Alabama

## 10 December Hail Case

**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**

## KHTX NEXRAD

## ARMOR 1.3 degree PPI scan at 17:55 UTC on 10 Dec. 04

**Particle Identification**

***Reflectivity [dBZ]***

## At 17:55 IC fl. rate ~ 3/minute in southern cell

**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 Observed Flashes Precede Hail Report

**LMA Observed Flashes Precede Hail Report**

## 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

## 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

## 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

## Science Mission Directorate - Project Columbia Investigation

_**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 Center @  MSFC**

_**Co-Is/Partners**_

- Kate La Casse and Stephanie Haines,  University of Alabama in Huntsville
- Gary Jedlovec, NASA @ 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

- 100,000 Processor Hours awarded March 2005

- Award number: SMD-Dec04- 0036

_**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.*

## 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**

## 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**

## WRF vs Eta Forecast, 14 July 2005

## NLDN Observed Lightning, 14 July 2005

**NLDN Observed Lightning, 14 July 2005**