Forecasting Thunderstorm Anvils for NASA Space Shuttle Operations

Kurt M. Van Speybroeck NOAA/NWS Spaceflight Meteorology Group, Houston, TX

Jon Zeitler, NOAA/NWS Austin/San Antonio, TXMatthew Bunkers, NOAA/NWS Rapid City, SD

Forecasting Thunderstorm Anvils for NASA Space Shuttle Operations

Kurt M. Van Speybroeck NOAA/NWS Spaceflight Meteorology Group, Houston, TX

Jon Zeitler, NOAA/NWS Austin/San Antonio, TXMatthew Bunkers, NOAA/NWS Rapid City, SD

Spaceflight Meteorology Group (SMG)Spaceflight Meteorology Group (SMG) Applied Meteorology Unit (AMU) Operational Anvil Tool

Applied Meteorology Unit (AMU) Operational Anvil Tool

NWS Spaceflight Meteorology Group provides operational and staff meteorology support to NASA’s human spaceflight program at Johnson Space Center (JSC).

Landing forecasts for Space Shuttle missions and simulations:

• Return to Launch (RTLS)

• Ascent Emergencies

• Transoceanic Abort Landing (TAL)

• On orbit emergencies

• End of Mission (EOM)

Forecast Challenges Unique to SMG:• Prediction of location and dissipation of

electrified anvil clouds• Dissipation and movement of clouds formed

from cumulonimbus• Convective initiations associated with the

development of electrified cumulus and

thunderstorms.

Rationale for avoidance of thunderstorm anvil

clouds is the potential for natural and / or

triggered lightning from the orbiter.

NWS Spaceflight Meteorology Group provides operational and staff meteorology support to NASA’s human spaceflight program at Johnson Space Center (JSC).

Landing forecasts for Space Shuttle missions and simulations:

• Return to Launch (RTLS)

• Ascent Emergencies

• Transoceanic Abort Landing (TAL)

• On orbit emergencies

• End of Mission (EOM)

Forecast Challenges Unique to SMG:• Prediction of location and dissipation of

electrified anvil clouds• Dissipation and movement of clouds formed

from cumulonimbus• Convective initiations associated with the

development of electrified cumulus and

thunderstorms.

Rationale for avoidance of thunderstorm anvil

clouds is the potential for natural and / or

triggered lightning from the orbiter.

PARAMETERPARAMETER LIMITLIMIT

Cloud Ceiling HeightCloud Ceiling Height >= 8,000 feet>= 8,000 feet

Surface visibilitySurface visibility >= 5 statute miles>= 5 statute miles

Crosswind Day/NightCrosswind Day/Night <= 15 knots / <= 12 knots<= 15 knots / <= 12 knots

HeadwindHeadwind <= 25 knots<= 25 knots

TailwindTailwind <= 15 knots (peak)<= 15 knots (peak)<=10 knots (2-minute <=10 knots (2-minute average)average)

Average vs. Peak WindAverage vs. Peak Wind <= 10 knot difference<= 10 knot difference

PrecipitationPrecipitation None within 30 Nautical None within 30 Nautical MilesMiles

Thunderstorm,Thunderstorm,Including anvil cloudIncluding anvil cloud

None within 30 Nautical None within 30 Nautical MilesMiles

TurbulenceTurbulence <= Moderate<= Moderate

Detatched non-transparent Detatched non-transparent Anvil < 3 hours oldAnvil < 3 hours old

Not within 20 Nautical Not within 20 Nautical MilesMiles

Weather Flight Rules: Daylight End of Mission (EOM) landing. Flight rules vary depending on site, day v. night,

type of landing, and mission duration.

GOES-12 Vis Image of exhaust plume from STS-118 orbiter (Endeavour)

NWS/SMG Technique Development Unit (TDU) and Applied Meteorology Unit (AMU) began developing an operational tool that would aid meteorologist in predicting movement and timing of observed thunderstorm anvils. (AMU 2000)

The idea of an “Anvil Tool” for the Meteorological Interactive Data Display System (MIDDS) and the Advanced Weather Information Processing System (AWIPS) was born.

2000 - SMG TDU and AMU develop “Proof of Concept” for the anvil tool concept.

2002 - AMU Improved Anvil Forecasting Phase II Final Report

2002-2007 - USAF 45th Weather Squadron and SMG have been using the operational anvil forecasting tool GUI in MIDDS and

AWIPS

2000 - SMG TDU and AMU develop “Proof of Concept” for the anvil tool concept.

2002 - AMU Improved Anvil Forecasting Phase II Final Report

2002-2007 - USAF 45th Weather Squadron and SMG have been using the operational anvil forecasting tool GUI in MIDDS and

AWIPS

How It Works

• Thunderstorm Anvils are observed

•Terminus is “fixed” either at KSC launch facility or the Shuttle Landing Facility (SLF)

•Threat corridor is a 30 degree sector width

•Threat sector direction is determined from the 300 hPa-150 hPa layer average wind direction (observed/model)

•The 1-, 2-, and 3-hour distance arcs are upwind and determined from the 300 hPa-150 hPa layer average wind speed.

AWIPS Anvil tool product and GUI

Example: Thunderstorm anvils building/moving into threat corridor. Low level storm motion differs from anvil level

observations.

• Storms that produce anvils, currently must develop in the threat sector

• Threat sector/corridor based on anvil level winds only

• Does not account for storms moving in/out of the current threat sector

• Advection and propagation

• Updraft movement contributing to new anvil coverage area

• Advances in storm motion prediction techniques from 2000 to present

• Bunkers storm motion (B2K methodology)

•Gust Front, Outflow boundaries, sea breeze convergence

Constraints/Additional Data

Modern Storm Motion MethodologyModern Storm Motion Methodology

© Tom Warner

The movement of a convective element with the mean flow throughout a representative tropospheric layer (momentum).

200

500

700

850

Sfc

Mean wind

Photo credit: Tom Warner Graphic credit/reference: Matthew Bunkers, Predicting Super Cell Motion in Operations

Teletraining 03/2005

• Short term (1 hr) forecast - updraft location.

•Advection (horizontal momentum) currently in anvil GUI

•Propagation

•3 ingredients for convection•Moisture

•Lift

•Instability

•Bunkers method B2K

•Empirically derived using isolated supercell thunderstorms

•Boundaries

•Surface features

•Orographic forcing

1) Plot a representative mean wind (e.g., 0-6km, 0-8km, 1-7km)

2) Draw a shear vector from the BL to 5.5-6km

3) Draw a line that both passes through the mean wind and is orthogonal to the shear vector (i.e., the updraft-shear propagation component)

4) Plot the RM and LM supercells 7-8 m/s from the mean wind (this can be variable)

B2K Motion

Test Cases/Proof of Concept• Archive/Analysis of anvil days with supercell/storm motion

•Addition of B2K storm motion to anvil tool GUI output

•Add mean wind (storm motion) if applicable

•Analysis of anvil tool plus storm motions for predictability

• Add radio button for manual input of storm motion

•Adjust the threat corridor orientation, accounting for calculated storm motion

•Increase confidence of thunderstorm anvils forecast to impact KSC and other NASA support facilities

Modifications/Additions

Matthew Bunkers, Predicting Super Cell Motion in Operations Teletraining 03/2005

Lambert, W. C., 2000: Improved anvil forecasting: Phase I Final Report. NASA Contractor Report CR-2000-208573, Kennedy Space Center, FL; 24 pp [available from ENSCO, Inc., 1980 N. Atlantic Ave., Suite 230, Cocoa Beach, FL 32931].

Lambert, W. C., 2002: Improved Anvil Forecasting: Phase II Final Report. NASA Contractor Report CR-2002-211170, Kennedy Space Center, FL; 19 pp [available from ENSCO, Inc., 1980 N. Atlantic Ave., Suite 230, Cocoa Beach, FL 32931].

Bunkers, M. J., and B. A. Klimowski, J. A. Zeitler, R. L. Thompson, M. L. Weisman, 2000: Predicting Supercell Motion Using a New Hodograph Technique; Wea. and Fcst, 15, 61-79

References

Brody, F. C., D. Bellue, R. Lafosse, and T. Oram, 1997: The Operations of the Spaceflight Meteorology Group; Wea. Fcst, 12, 526-544.

Hoeth, B., T. Garner, R. LaFosse and T. D. Oram, 2007: Tools Used by the Spaceflight Meteorology Group to Evaluate Space Shuttle Weather Flight Rules for Landing Forecasts; 23rd Conference on Interactive Information Processing Systems for Meteorology, Oceanography and Hydrology, San Antonio, TX

Oram, T. D., T. Garner and B. Hoeth, 2005: Use of Lightning Data for Space Shuttle and Soyuz Re-entry and Landing Forecasts at the Johnson Space Center; AMS Conference on the Meteorological Applications of Lightning Data, San Diego, CA

References