2013-2014 wpc winter weather desk operations and verification
DESCRIPTION
2013-2014 WPC Winter Weather Desk Operations and Verification. Dan Petersen Winter weather focal point Keith Brill , David Novak , Wallace Hogsett , and Mark Klein. Weather Prediction Center - Winter Weather Operations. Review of Winter Weather Desk Operations - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: 2013-2014 WPC Winter Weather Desk Operations and Verification](https://reader036.vdocuments.mx/reader036/viewer/2022062316/56816727550346895ddbc1ee/html5/thumbnails/1.jpg)
2013-2014 WPC Winter Weather Desk Operations and Verification
Dan Petersen Winter weather focal point Keith Brill , David Novak , Wallace Hogsett, and Mark Klein
![Page 2: 2013-2014 WPC Winter Weather Desk Operations and Verification](https://reader036.vdocuments.mx/reader036/viewer/2022062316/56816727550346895ddbc1ee/html5/thumbnails/2.jpg)
Weather Prediction Center - Winter Weather Operations
• Review of Winter Weather Desk Operations
• Changes to Operations for 2013-14 season• Experimental forecasts for 2013-14 season• Upcoming Winter Weather Experiment
![Page 3: 2013-2014 WPC Winter Weather Desk Operations and Verification](https://reader036.vdocuments.mx/reader036/viewer/2022062316/56816727550346895ddbc1ee/html5/thumbnails/3.jpg)
Winter weather desk schedule• 01-10z and 13-22z are the shifts • Deadlines for accumulations are 05/17z
(day 1), 0545/1745z (day 2), and 0615/1815z (day 3)
• 0615-0815z, 1815-2015z collaborate with WFOs, do low tracks/discussion
• 0815z/2015z send snow/ice probabilities• 0830-1000z/2030-2200z edit and post test
days 4-7 probabilities
![Page 4: 2013-2014 WPC Winter Weather Desk Operations and Verification](https://reader036.vdocuments.mx/reader036/viewer/2022062316/56816727550346895ddbc1ee/html5/thumbnails/4.jpg)
Current WPC Winter Weather Operations
Forecasts at http://www.wpc.ncep.noaa.gov/wwd/internal
Forecasts for both snow
and freezing rain
Days 1, 2, and 3 snow
and freezing rain accumulations
![Page 5: 2013-2014 WPC Winter Weather Desk Operations and Verification](https://reader036.vdocuments.mx/reader036/viewer/2022062316/56816727550346895ddbc1ee/html5/thumbnails/5.jpg)
Current WPC Winter Weather Operations
Forecasts at http://www.wpc.ncep.noaa.gov/wwd/winter_wx.shtml
Forecasts for both snow
and freezing rain
![Page 6: 2013-2014 WPC Winter Weather Desk Operations and Verification](https://reader036.vdocuments.mx/reader036/viewer/2022062316/56816727550346895ddbc1ee/html5/thumbnails/6.jpg)
Current WPC Winter Weather Operations
Forecasts at http://www.wpc.ncep.noaa.gov/wwd/winter_wx.shtml
Forecasts for both
probabilities and
percentiles
Probabilities now cover 1-100 percent
![Page 7: 2013-2014 WPC Winter Weather Desk Operations and Verification](https://reader036.vdocuments.mx/reader036/viewer/2022062316/56816727550346895ddbc1ee/html5/thumbnails/7.jpg)
http://www.wpc.ncep.noaa.gov/pwpf/about_pwpf_products.shtml
Current WPC Winter Weather Operations
In the percentiles,
you can choose
options for the 5th, 10th,
25th, 75th, 90th, 95th
percentiles
![Page 8: 2013-2014 WPC Winter Weather Desk Operations and Verification](https://reader036.vdocuments.mx/reader036/viewer/2022062316/56816727550346895ddbc1ee/html5/thumbnails/8.jpg)
Current WPC Winter Weather Operations
In the map overlays, you can choose to
display contours
![Page 9: 2013-2014 WPC Winter Weather Desk Operations and Verification](https://reader036.vdocuments.mx/reader036/viewer/2022062316/56816727550346895ddbc1ee/html5/thumbnails/9.jpg)
Changes in Operations for 2013-14
• Expanded Probabilistic Snow and Ice Forecasts provided on web site in 2012-13 now operational
• Probability forecasts now provided in Google Maps and cover 72 hour forecast
• 33-member ensemble including: WPC deterministic forecast, 21 SREF members, GFS, GEFS Mean, 5 GEFS members (new for 2013-14), ECMWF, ECMWF Ensemble Mean, Canadian Global, UKMET snowfall/freezing rain forecasts
![Page 10: 2013-2014 WPC Winter Weather Desk Operations and Verification](https://reader036.vdocuments.mx/reader036/viewer/2022062316/56816727550346895ddbc1ee/html5/thumbnails/10.jpg)
Forecast in six hour time steps
![Page 11: 2013-2014 WPC Winter Weather Desk Operations and Verification](https://reader036.vdocuments.mx/reader036/viewer/2022062316/56816727550346895ddbc1ee/html5/thumbnails/11.jpg)
Choose a forecast
Duration
![Page 12: 2013-2014 WPC Winter Weather Desk Operations and Verification](https://reader036.vdocuments.mx/reader036/viewer/2022062316/56816727550346895ddbc1ee/html5/thumbnails/12.jpg)
Choose a user interface
![Page 13: 2013-2014 WPC Winter Weather Desk Operations and Verification](https://reader036.vdocuments.mx/reader036/viewer/2022062316/56816727550346895ddbc1ee/html5/thumbnails/13.jpg)
Choose opacity
![Page 14: 2013-2014 WPC Winter Weather Desk Operations and Verification](https://reader036.vdocuments.mx/reader036/viewer/2022062316/56816727550346895ddbc1ee/html5/thumbnails/14.jpg)
Experimental Forecasts for 2013-2014
• In an effort to determine winter weather forecast skill for days 4-7, we will be issuing internal probabilistic forecasts of combined snow/freezing rain totals of 0.10” liquid equivalent for each 24 hour period for
Day 4 Day 5 Day 6 Day 7
![Page 15: 2013-2014 WPC Winter Weather Desk Operations and Verification](https://reader036.vdocuments.mx/reader036/viewer/2022062316/56816727550346895ddbc1ee/html5/thumbnails/15.jpg)
Probability of combined snow/ice of 0.10” Liquid Equiv. for each 24 hour pd
![Page 16: 2013-2014 WPC Winter Weather Desk Operations and Verification](https://reader036.vdocuments.mx/reader036/viewer/2022062316/56816727550346895ddbc1ee/html5/thumbnails/16.jpg)
Experimental Forecasts for 2013-2014
• Initial methodology will be similar to probabilistic rain forecast, with WPC qpf as the mode (given most weight)
• All ECMWF and GEFS members used to calculate probability of QPF>0.10”
• Precipitation type is based on GEFS members• Edits based on operational ECMWF, ensemble
clusters of ECMWF snowfall forecasts, operational GFS (any non-GEFS solutions)
![Page 17: 2013-2014 WPC Winter Weather Desk Operations and Verification](https://reader036.vdocuments.mx/reader036/viewer/2022062316/56816727550346895ddbc1ee/html5/thumbnails/17.jpg)
2013 Winter Weather Experiment: Improving Snow forecasts in mixed precipitation type locations
• Test methodology: Modify the SLR in the NAM by accounting for Instantaneous:
- Percent frozen precipitation- Rime factor
Percent frozen < 10%
Rime Factor > 40(heavily rimed)
24hr snowfall(rime factor modification)
24hr snowfall (Roebber Technique)
![Page 18: 2013-2014 WPC Winter Weather Desk Operations and Verification](https://reader036.vdocuments.mx/reader036/viewer/2022062316/56816727550346895ddbc1ee/html5/thumbnails/18.jpg)
2013 Winter Weather Experiment: Improving Snow Accumulation
forecasts in mixed precipitation type locations
• Potential Benefits:- Data available hourly- More representative of how much of each- precipitation type accumulates- Snow accumulations are lowered when snow is mixed with ice pellets and/or rain- This will be implemented in AWIPS NAM - snow accumulations Q3 2014 Testing forthcoming in the SREF and GFS
18
![Page 19: 2013-2014 WPC Winter Weather Desk Operations and Verification](https://reader036.vdocuments.mx/reader036/viewer/2022062316/56816727550346895ddbc1ee/html5/thumbnails/19.jpg)
• Explored the utility of Day 4 and Day 5 winter weather outlook
Day 4 forecast valid 00Z 3 February 2013
Observed 24 h snowfall ending 00Z 3 February 2013
Evolved to probability of 0.10” liquid- equivalent falling as frozen precipitation
Winter Weather Experiment 2013
![Page 20: 2013-2014 WPC Winter Weather Desk Operations and Verification](https://reader036.vdocuments.mx/reader036/viewer/2022062316/56816727550346895ddbc1ee/html5/thumbnails/20.jpg)
Winter Weather Experiment 2014
http://www.esrl.noaa.gov/exref/
Evaluate the Earth System Research Lab’s Experimental Research Ensemble Forecast for Days 1-3
![Page 21: 2013-2014 WPC Winter Weather Desk Operations and Verification](https://reader036.vdocuments.mx/reader036/viewer/2022062316/56816727550346895ddbc1ee/html5/thumbnails/21.jpg)
• Review use of Parallel (test) version of the Global Forecast System (GFS) for snow and freezing rain forecasting, especially on days 4-7
• Review use of the parallel version of the NAM for snow and freezing rain forecasting, especially for days 1-3 and the fraction of frozen precipitation diagnostic
• http://www.emc.ncep.noaa.gov/mmb/mmbpll/opsnam/
Winter Weather Experiment 2014
![Page 22: 2013-2014 WPC Winter Weather Desk Operations and Verification](https://reader036.vdocuments.mx/reader036/viewer/2022062316/56816727550346895ddbc1ee/html5/thumbnails/22.jpg)
Summary• Expanded product suite
– probabilistic snow/freezing rain forecast suite to include 24, 48 and 72 hour totals out thru day 3
– Day 4-7 winter weather outlook (internal) introduced in 2013-14
• Winter Weather Experiment
– showed use of fraction of frozen precipitation and rime factor can be used to improve snow forecasts (implemented in next NAM upgrade).
– 2014 Winter Weather Experiment coming in January-February, to review Experimental Short Range Ensembles and parallel GFS and NAM forecasts
![Page 24: 2013-2014 WPC Winter Weather Desk Operations and Verification](https://reader036.vdocuments.mx/reader036/viewer/2022062316/56816727550346895ddbc1ee/html5/thumbnails/24.jpg)
24
2012-13 Verification of WPC Low Tracks (position at each forecast hour)
Lowest errors: Blend of gfs+nam 12-36 hours, gfs+ecmwf at 48, ECMWF at 60, WPC at 72 hours
Among the models: GFS 12-24 hours, ECMWF best 36-72 h