WPC Verification Statistics

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WPC Verification

Forecast Products

QPF's: 24-Hourly 6-Hourly Days 4-5/6-7 5-Day Total
Medium Range: Min Temps Max Temps Prob of Pcpn (PoP) WPC Grids
Sea-level Pressure

Verification for specific events: Hurricane Isaac QPF Hurricane Sandy QPF

Quantitative Precipitation Forecasts

How Threat Scores and Bias are Computed

24-Hourly QPF's

Monthly Record Threat Scores

Annual WPC Day-1 / Day-2 / Day-3 Threat Scores and Observed Areal Coverage; Annual WPC Day-1 / Day-2 / Day-3 Bias

.50 inch (1961-2020)	1.00 inch (1961-2020)	2.00 inches (1970-2020)
Threat Bias	Threat Bias	Threat Bias

Annual WPC vs. NWP Guidance Threat Scores 1993-2020

	1.00 inch
Day 1	Threat	Percent Improvement Over NWP

Monthly WPC vs. NWP Guidance Threat Scores and Bias July 2020 to July 2021

	.50 inch	1.00 inch	2.00 inches
Day 1	Threat Bias	Threat Bias	Threat Bias
Day 2	Threat Bias	Threat Bias	Threat Bias
Day 3	Threat Bias	Threat Bias	Threat Bias

Monthly WPC Threat Score and Bias Comparisons (.50", 1.00", 2.00") July 2020 to July 2021

Day 1	Day 2	Day 3
Threat Bias	Threat Bias	Threat Bias

Monthly WPC Threat Score and Bias Comparisons (Day 1 / Day 2 / Day 3) July 2020 to July 2021

.50 inch	1.00 inch	2.00 inches
Threat Bias	Threat Bias	Threat Bias

NAM and GFS QPF Verification by Region

Object-oriented Verification

6-Hourly QPF's

Monthly Record Threat Scores

Monthly WPC vs. NWP Guidance Threat Scores Update July 2020 to July 2021

00-06 Hours

.25 inch

.50 inch

Monthly WPC vs. NWP Guidance Threat Scores Day 1 July 2020 to July 2021

06-12 Hours	.25 inch	.50 inch
12-18 Hours	.25 inch	.50 inch
18-24 Hours	.25 inch	.50 inch
24-30 Hours	.25 inch	.50 inch

Monthly WPC vs. NWP Guidance Threat Scores Day 2 July 2020 to July 2021

30-36 Hours	.25 inch	.50 inch
36-42 Hours	.25 inch	.50 inch
42-48 Hours	.25 inch	.50 inch
48-54 Hours	.25 inch	.50 inch

Monthly WPC vs. NWP Guidance Threat Scores Day 3 July 2020 to July 2021

54-60 Hours	.25 inch	.50 inch
60-66 Hours	.25 inch	.50 inch
66-72 Hours	.25 inch	.50 inch
72-78 Hours	.25 inch	.50 inch

WPC vs. NWP Guidance - Threat Scores October 2020 to July 2021

All 6-Hour Periods

.25 inch

.50 inch

Days 4-5/6-7 QPF's

Annual WPC Days 4-5/6-7 Threat Scores and Observed Areal Coverage (2001-2020)

.50 inch	1.00 inch	2.00 inches
Threat	Threat	Threat

Monthly WPC vs. NWP Guidance Threat Scores and Bias July 2020 to July 2021

	.50 inch	1.00 inch	2.00 inches
Days 4-5	Threat Bias	Threat Bias	Threat Bias
Days 6-7	Threat Bias	Threat Bias	Threat Bias

Monthly WPC Threat Score and Bias Comparisons .50", 1.00", 2.00" July 2020 to July 2021

Days 4-5	Threat	Bias
Days 6-7	Threat	Bias

5-Day Total QPF's

Monthly WPC vs. NWP Guidance Threat Scores and Bias July 2020 to July 2021

.50 inch	1.00 inch	2.00 inches	3.00 inches	4.00 inches
Threat Bias	Threat Bias	Threat Bias	Threat Bias	Threat Bias

Monthly WPC Threat Score and Bias Comparisons .50", 1.00", 2.00", 3.00", 4.00" July 2020 to July 2021

Threat

Bias

Medium-Range Forecasts

Overview of data plotted on annual charts

Minimum Temperatures

Annual Mean Absolute Error (MAE) Charts (1972 - 2020)

WPC MAE for days 3-7 min temp fcsts

WPC -vs- Guidance MAE for day 3 min temp fcsts

WPC -vs- Guidance MAE for day 4 min temp fcsts

WPC -vs- Guidance MAE for day 5 min temp fcsts

WPC -vs- Guidance MAE for day 6 min temp fcsts

WPC -vs- Guidance MAE for day 7 min temp fcsts

Monthly Performance Charts (January 2020 - July 2021)

WPC RMS errors for Days 3-7 min temp fcsts

WPC percent improvement over MOS MAE (adjusted stations only) for Days 3-7 min temp fcsts

WPC winning percent vs MOS for Days 3-7 min temp fcsts

Year-to-Date Performance Chart (January - July 2021)

WPC improvement over MOS MAE, including percentage of stations adjusted, for Days 3-7 min temp fcsts

Maximum Temperatures

Annual Mean Absolute Error (MAE) Charts (1972 - 2020)

WPC MAE for days 3-7 max temp fcsts

WPC -vs- Guidance MAE for day 3 max temp fcsts

WPC -vs- Guidance MAE for day 4 max temp fcsts

WPC -vs- Guidance MAE for day 5 max temp fcsts

WPC -vs- Guidance MAE for day 6 max temp fcsts

WPC -vs- Guidance MAE for day 7 max temp fcsts

Monthly Performance Charts (July 2020 - July 2021)

WPC RMS errors for Days 3-7 max temp fcsts

WPC percent improvement over MOS MAE (adjusted stations only) for Days 3-7 max temp fcsts

WPC winning percent vs MOS for Days 3-7 max temp fcsts

Year-to-Date Performance Chart (January - July 2021)

WPC improvement over MOS MAE, including percentage of stations adjusted, for Days 3-7 max temp fcsts

Probability of Precipitation (PoP)

Monthly Performance Charts - 24-Hour PoP (July 2020 - July 2021)

WPC Brier scores for days 3-7 PoP fcsts

WPC percent improvement over MOS Brier score (adjusted stations only) for days 3-7 PoP fcsts

WPC winning percent vs MOS for Days 3-7 PoP fcsts

Year-to-Date Performance Chart - 24-Hour PoP (January - July 2021)

WPC improvement over MOS Brier score, including percentage of stations adjusted, for Days 3-7 PoP fcsts

Monthly Performance Charts - 12-Hour PoP (December 2018 - December 2019)

WPC Brier scores for days 3-7 12-Hour PoP forecasts

WPC percent improvement over MOS Brier score for days 3-7 12-Hour PoP forecasts

WPC Gridded Medium-Range Forecasts

How grids are verified

Monthly Performance Charts (December 2019)
Note: MAE = Mean Absolute Error

Forecasts prepared by WPC meteorologists

NBM/WPC/NDFD Minimum Temperature (Days 4-7)	MAE	Bias
NBM/WPC/NDFD Maximum Temperature (Days 4-7)	MAE	Bias
NBM/WPC/NDFD 12-Hour PoP (Days 4-7)	Brier Score

Products derived from forecasts prepared by WPC meteorologists

NBM/WPC/NDFD Dew Point Temperature
(valid every 6 hours from F90-F180) MAE Bias

NBM/WPC/NDFD Wind Speed
(valid every 6 hours from F90-F180) MAE Bias

NBM/WPC/NDFD Wind Direction
(valid every 6 hours from F90-F180) MAE Bias

WPC/NDFD Cloud Cover
(valid every 6 hours from F90-F180) MAE Bias

Mean Sea Level Pressure (PMSL)

WPC -vs- Guidance Anomaly Correlations


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Page last modified: Wednesday, 25-Aug-2021 04:43:00 UTC