120 likes | 241 Views
Increasing Observations to Improve Freezing Rain Analysis. Joseph Puma NCAS- Howard University. HMT-HPC Winter Weather Experiment January 10-February 11, 2011. Goals Can high resolution models improve Day 1 forecasts of precipitation type and amount?
E N D
Increasing Observations to Improve Freezing Rain Analysis Joseph Puma NCAS- Howard University
HMT-HPC Winter Weather Experiment January 10-February 11, 2011 • Goals • Can high resolution models improve Day 1 forecasts of precipitation type and amount? • Can we better quantify and communicate winter weather uncertainty for Day 1-2 forecasts? • Experiment Activities • Create snow and ice accumulation forecasts using experimental guidance • Subjectively evaluate experimental guidance
Automated Freezing Rain Analysis • Experiment revealed problems with current analysis. • Amounts too low • Areal coverage limited • Current Technique • Station observations used to determine precipitation type • NPVU QPE used to assign accumulations to freezing rain reports at stations • Barnes Analysis used to interpolate accumulation to freezing rain analysis grid. (20km)
Enhanced Freezing Rain Analysis • Goals: • Does adding observations from Local Storm Reports (LSR) and Public Information Statement (PNS) improve freezing rain analysis? • Can this be done by a forecaster on an operational shift?
Enhanced Freezing Rain Analysis • 4 cases from the Winter Weather Experiment with widespread freezing rain • Methodology • Search LSR and PNS for freezing rain/ice reports • Create text file with information about location, duration, time of report, and observed amount in specified format. • Assume 12 hr accumulation for amounts < .25 in • Assume 24 hr accumulation for amounts >.25 in • One entry per location and unique time interval • Add new data to original analysis and re-compute using GEMPAK
00z 4 February 2011 Original Analysis Enhanced Analysis
00z 3 February 2011 Enhanced Analysis Original Analysis
Enhanced Analysis Results • New analysis method results in better coverage and a more accurate depiction of observed freezing rain • Not practical to do on shift • 4-5 hours per case to enter data
Potential Improvements • Short Term • Web Entry • Allows for easier data entry • Reduces time spent formatting data • Long Term • Systematic data collection through AWIPS 2
Challenges • Fully Automated Process • Format of LSR and PNS doesn’t lend itself to automation • Freezing rain reported inconsistently • Multiple phrases- freezing rain, ice, ice storm • Search both LSR and PNS statements • Numerical value sometimes differed from value reported in comments • Observations
Questions? Joseph Puma joepuma93@gmail.com 847-894-5525