National Convective Weather Forecasts Cindy Mueller

Transcription

1 National Convective Weather Forecasts Cindy Mueller National Center for Atmospheric Research Research Applications Program

2 National Forecast Demonstration hr Convection Forecasts Collaborative forecast between Airlines, AWC and CWSUs CTFP 98 Test Collaborative Decision Making Goals Airline Operational Flexibility Airline Access to Usable Airspace Operational Efficiency Predictability in expected flight time. 1-2 hr National Forecasts Automated (2 hr in FY99) Procedures Strategic (2-6hrs) Collaborative Routing Tactical (0-2 hrs) Severe Weather Advisory Program Routes (SWAP) Low Altitude Arrival & Departure Routes Benefits Time Savings Delay Avoidance

3 Automated Products (5-10 min update) TCWF (1km) and NCWF (4 km) Forecast Area = Storm Area Forecaster Products (60 min update) Convective SIGMET Forecast Area > Storm Area Qualitative Assessment of Forecast Accuracy Convective precipitation for spatial scale of a few kilometers Expert system Forecast Accuracy FY02-03 Automated Demonstration (5-10 min update) Forecast Area = Storm Area Local explicit cloud model CCFP (twice a day) Expert system = Forecaster Forecast area >> Storm area Extrapolation Tactical Strategic TRACON ARTCC National Mesoscale model (POP) Forecast Period (hrs) Modified from Browning, 1980

4 0-2 hr Extrapolation Forecast for Enroute Sponsor - FAA-Aviation Weather Research Program NCWF product provides: Convective Hazard Detection Field based on radar and lightning data 1 hr Extrapolation Forecast Storm tops and motion 5 min updates Airline Dispatch accessed product from the WWW or CDMnet 24/7 Operation Runs at AWC AWC displays product on forecaster workstations Tech center usability studies conducted in 1998 and 1999 at airlines

5 Convective Hazard Detection Radar Lightning Rate Radar WSI - VIL and Echo Tops National Mosaics Echo Tops allows removal of AP and ground clutter Detection Field and Forecast Lightning Global Atmospherics Lightning provides; More timely product Radar is 10 to 25 min old Lightning is < 5 min Highlights updraft regions Fills in regions of radar data voids or latency

6 Combined VIL and Lightning Radar Reflectivity Radar Reflectivity w/ lightning Detection Jan 23, 1999 at 14:40 GMT

7 Extrapolation Forecast Eliminate Stratiform Stratiform-Convective Partitioner Steiner and Houze (1995) Remove perishable scales Wilson 1966 Elliptical filter - Wolfson 1999 Determine motion vectors Dual-threshold cell tracker Dixon and Weiner (1993)

8 NCWF Performance 60 min forecast overlaid on convective hazard detection at valid time

9 Statistics for May 12-13, 2000 Probability of Detection (Perfect = 1.0) False Alarm Rate (Perfect = 0.0) Critical Success Index (Perfect = 1.0) Area Coverage

10

11

12

13

14 Approach to Growth and Decay Use RUC2 data for the first-guess forecast region based on environmental stability and synoptic scale triggers fronts or the dry line high CAPE/ low CIN environmental shear Use the satellite and radar data to determine regions of potential storm development. Satellite cloud lines and radar fine lines to determine specific location of primary boundary or secondary boundaries. Satellite CldGrowth for cloud type and growth. Initial storms forming along line.

15 Forecast Requirements for growth and decay - Enroute Large-scale (synoptic) environment stability vertical wind shear forcing (winds) Cloud characteristics (proxy for stability) type growth Storm characteristics position growth rate - storm structure storm merger storm boundary interaction

16 Summary NCWF Convective Hazard Detection and Extrapolation forecast is running operationally and available to aviation users via the WWW and CDMnet Based on analysis of 1998 and 1999 data there is a good potential for providing national-scale Growth and Decay forecast based on RUC, radar and satellite data. Currently developing Growth and Decay system to provide 1-2 hr forecast.