Using a Mesoscale Model to Using a Mesoscale Model to Identify Convective Initiation Identify Convective Initiation

in an ARTCC/CWSU in an ARTCC/CWSU EnvironmentEnvironment

Warren R. SnyderWarren R. SnyderNOAA/NWS Weather Forecast OfficeNOAA/NWS Weather Forecast Office

Albany, New YorkAlbany, New York

Mark R. McKinleyMark R. McKinleyNOAA/NWS Center Weather Service UnitNOAA/NWS Center Weather Service Unit

Oberlin, OhioOberlin, Ohio

Allison R. VeghAllison R. VeghDepartment of Earth and Atmospheric SciencesDepartment of Earth and Atmospheric Sciences

University at Brockport State University of New YorkUniversity at Brockport State University of New YorkBrockport, New YorkBrockport, New York

Why does convective initiation matter to Why does convective initiation matter to the National Airspace System (NAS)the National Airspace System (NAS)

Causes of air traffic DelaysCauses of air traffic Delays• 76 % of involve weather76 % of involve weather• 24% involve thunderstorms24% involve thunderstorms• 17% Ceilings 17% Ceilings • 14% each for visibilities and wind14% each for visibilities and wind

Result…Ground Stops & DelaysResult…Ground Stops & Delays• Significant costs from $3K to 300K/flight Significant costs from $3K to 300K/flight • Safety Issues Safety Issues • Your sitting in the airport delayed for hours or Your sitting in the airport delayed for hours or

days !!!days !!!

Purpose of the StudyPurpose of the Study Improve convection initiation forecasts of Improve convection initiation forecasts of

CWSU Oberlin using a mesoscale modelCWSU Oberlin using a mesoscale model Can better forecasts reduce ground stops, Can better forecasts reduce ground stops,

improving convection avoidance, and earlier improving convection avoidance, and earlier or later re-routings or later re-routings

Proof of conceptProof of concept How much $$$ can the industry save?How much $$$ can the industry save? To run the full modeling system in a CWSU To run the full modeling system in a CWSU

costs $49 a month for a T1 and $4000 for the costs $49 a month for a T1 and $4000 for the PCPC

How much does jet fuel cost?How much does jet fuel cost?

WSETA project at CWSU Oberlin, WSETA project at CWSU Oberlin, Ohio and WFO Albany, NYOhio and WFO Albany, NY

Training Provided to CWSU Staff April 2004Training Provided to CWSU Staff April 2004 Model data posted on CSTAR server twice a day via gempak Model data posted on CSTAR server twice a day via gempak

graphics on the internet. graphics on the internet. SUNY Student compared six fields identified by MIC/SOO as most SUNY Student compared six fields identified by MIC/SOO as most

likely to be indicative of convective initiation using data from likely to be indicative of convective initiation using data from Summer 2004 to early June 2005. Summer 2004 to early June 2005.

Parameters with best performance Parameters with best performance • Hourly Convective PrecipitationHourly Convective Precipitation• 700 HPA Omega 700 HPA Omega

Modeling system - Dell Pentium 4 , 2400 mHz Linux PCModeling system - Dell Pentium 4 , 2400 mHz Linux PC Model run for 24 hours. 06 UTC and 18 UTC runs with output Model run for 24 hours. 06 UTC and 18 UTC runs with output

posting 0800 UTC/2000 UTCposting 0800 UTC/2000 UTC Kain-Fritcsh Convective Parameterization, Nested - Outer nest Kain-Fritcsh Convective Parameterization, Nested - Outer nest

resolution is 15 km, Inner Nest 7.5 km resolution, Diffusion is 0.30 resolution is 15 km, Inner Nest 7.5 km resolution, Diffusion is 0.30 versus 1.0 in operational models. Most parameters configured at versus 1.0 in operational models. Most parameters configured at SOO/STRC baseline. SOO/STRC baseline.

Study Area – Oberlin Service Area Study Area – Oberlin Service Area Squared offSquared off

Results Part IResults Part I

Definitions - % of convection Definitions - % of convection in area forecasted by model in area forecasted by model parameterparameter• Good – 75% or moreGood – 75% or more• Acceptable – 25% to 75% Acceptable – 25% to 75% • Poor – Less than 25%Poor – Less than 25%

Performance 850 hPa Theta-E

HrlyConvective Precipitation

700 hPa Omega

850 hPa Jet 250 hPa Divergence

BL Convergence

Good 6 5 9 4 6 6

Acceptable 8 19 18 5 14 12

Poor 15 5 2 17 9 11

Good 21% 17% 31% 14% 21% 21%

Acceptable 28% 66% 62% 17% 48% 41%

Poor 52% 17% 7% 59% 31% 38%

HCP - Acceptable or Good 83%700 hPa Omega- Acceptable or Good 93%

Hourly Convective Precipitation Hourly Convective Precipitation (HCP) vs. 700 hPa Omega(HCP) vs. 700 hPa Omega

Part II – Comparing 700 hPa Part II – Comparing 700 hPa Omega and HCP forecasts to Omega and HCP forecasts to

NLDN DataNLDN Data Used all convective events from June to Used all convective events from June to

September 2005 in CWSU Oberlin areaSeptember 2005 in CWSU Oberlin area NLDN data plots every lightning stroke at NLDN data plots every lightning stroke at

exact lat/lon pointsexact lat/lon points Assess accuracy of model parameters in Assess accuracy of model parameters in

time and spacetime and space UAlbany students extracted the data UAlbany students extracted the data Software developed by Vasil Koleci to plot Software developed by Vasil Koleci to plot

lighting data hourly over the arealighting data hourly over the area 87 events identified, 3 dropped as only 87 events identified, 3 dropped as only

SHRA and no lightning occurredSHRA and no lightning occurred

Comparison of Model 700 hPa Comparison of Model 700 hPa Omega/HCP Convective Omega/HCP Convective

Configuration with NLDN dataConfiguration with NLDN data Excellent (4)–Model data match in location, Excellent (4)–Model data match in location,

and structure/orientation. and structure/orientation. Good – (3) If structure/orientation are very Good – (3) If structure/orientation are very

similar but location is off by 160 km, or similar but location is off by 160 km, or location is within 160 km and location is within 160 km and structure/orientation are differentstructure/orientation are different

Fair – (2) If they are both in the same ¼ of Fair – (2) If they are both in the same ¼ of a state or states, or overlap each other a state or states, or overlap each other 25% or less25% or less

Poor – (1) No matchPoor – (1) No match

Results for Configuration Results for Configuration

700 hPa Omega had an average of 700 hPa Omega had an average of 3.08 configuration. 74 events where 3.08 configuration. 74 events where good or excellent, only 10 fair and good or excellent, only 10 fair and poorpoor

HCP – Had an average 2.81 HCP – Had an average 2.81 configuration. 63 Events good or configuration. 63 Events good or excellent, 21 Fair or Poorexcellent, 21 Fair or Poor

Results for TimelinessResults for Timeliness 700 hPa Omega and HCP forecasted 700 hPa Omega and HCP forecasted

the time of initiation at the same the time of initiation at the same time in all but 9 casestime in all but 9 cases

Average model time error for Average model time error for convective initiation was 37.5 convective initiation was 37.5 minutesminutes• 54 events were forecast within an hour54 events were forecast within an hour• 19 events between one and two hours19 events between one and two hours• 11 events between two and three hours11 events between two and three hours

Distance ErrorDistance Error Distance from the model convection to the Distance from the model convection to the

actual lighting at initiationactual lighting at initiation Average for 700 hPA Omega 33 kmAverage for 700 hPA Omega 33 km

• All but one event within 240 km All but one event within 240 km • 240 km is the distance a jet travels in 15 240 km is the distance a jet travels in 15

minutesminutes Average for HCP 86 km. Average for HCP 86 km.

• All but 5 events within 240 kmAll but 5 events within 240 km Difference likely the result of the much Difference likely the result of the much

more specific locations of HCP versus the more specific locations of HCP versus the general broader areas of 700 hPa Omegageneral broader areas of 700 hPa Omega

Future DirectionsFuture Directions Model converted over to the WRFModel converted over to the WRF WRF data being provided to CWSUs at WRF data being provided to CWSUs at

Nashua and OberlinNashua and Oberlin Will undertake a similar study during the Will undertake a similar study during the

2007 convective season using the WRF2007 convective season using the WRF New products available such as model New products available such as model

Composite ReflectivityComposite Reflectivity

ReferencesReferences Based on ER Tech Attachment 2006-01 Based on ER Tech Attachment 2006-01

“Using a Mesoscale Model to Identify “Using a Mesoscale Model to Identify Convective Initiation in an Convective Initiation in an ARTCC/CWSU Environment” 2006: ARTCC/CWSU Environment” 2006: Snyder W.R, McKinley M.R. and Vegh Snyder W.R, McKinley M.R. and Vegh A.R. A.R.

Original Paper can be found online at Original Paper can be found online at http://www.werh.noaa.gov/SSD/erps/http://www.werh.noaa.gov/SSD/erps/

ta/ta2006-01.pdfta/ta2006-01.pdf