Skip Navigation Links weather.gov 
NOAA logo - Click to go to the NOAA homepage National Weather Service   NWS logo - Click to go to the NWS homepage
The Weather Prediction Center
Site Map News Organization
  DOC NOAA NWS NCEP Centers: AWC CPC EMC NCO NHC OPC SPC SWPC WPC

 
 

 
Follow the Weather Prediction Center on Facebook
WPC on Facebook
NCEP Quarterly Newsletter
WPC Home
Analyses and Forecasts
   National High & Low
   WPC Discussions
   Surface Analysis
   Days ½-2½ CONUS
   Days 3-7 CONUS
   Days 4-8 Alaska
   QPF
   PQPF
   Flood Outlook
   Winter Weather
   Storm Summaries
   Heat Index
   Air Quality
   Tropical Products
   Daily Weather Map
   GIS Products
Current Watches/
Warnings
Satellite and Radar Imagery
   Satellite Images
   National Radar
Verification
   WPC Verification
   NPVU
   Model Diagnostics
   Event Reviews
International Desks
Development and Training
   Development
WPC Overview
   About the WPC
   Staff
   WPC History
   Accomplishments
   Other Sites
   FAQs
Meteorological Calculators
Contact Us
   About Our Site
 
USA.gov is the U.S. Government's official web portal to all federal, state, and local government web resources and services.


WPC Verification
Forecast Products
 
QPF's:    24-Hourly    6-Hourly    Days 4-5    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 (1961-2012) 1.00 inch (1961-2012) 2.00 inches (1970-2012)
Threat Bias Threat Bias Threat Bias

Annual WPC vs. NWP Guidance Threat Scores
1993-2012
1.00 inch
Day 1 Threat Percent Improvement Over NWP

Monthly WPC vs. NWP Guidance Threat Scores and Bias
January 2012 to January 2013
.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")
January 2012 to January 2013
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)
January 2012 to January 2013
.50 inch 1.00 inch 2.00 inches
Threat Bias Threat Bias Threat Bias

NAM and GFS QPF Verification by Region


6-Hourly QPF's
Monthly Record Threat Scores

Monthly WPC vs. NWP Guidance Threat Scores
Update
January 2012 to January 2013
00-06 Hours .25 inch .50 inch

Monthly WPC vs. NWP Guidance Threat Scores
Day 1
January 2012 to January 2013
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
January 2012 to January 2013
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
January 2012 to January 2013
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
February 2012 to January 2013
All 6-Hour Periods .25 inch .50 inch


Days 4-5 QPF's
Monthly WPC vs. NWP Guidance Threat Scores and Bias
January 2012 to January 2013
.50 inch 1.00 inch 2.00 inches
Threat Bias Threat Bias Threat Bias

Monthly WPC Threat Score and Bias Comparisons
.50", 1.00", 2.00"
January 2012 to January 2013
Threat Bias


5-Day Total QPF's
Monthly WPC vs. NWP Guidance Threat Scores and Bias
January 2012 to January 2013
.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"
January 2012 to January 2013
Threat Bias


Medium-Range Forecasts

Overview of data plotted on annual charts

Minimum Temperatures

Annual Mean Absolute Error (MAE) Charts (1972 - 2012)
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 2011 - January 2012)
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-December 2012)
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 - 2012)
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 (January 2011 - January 2012)
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-December 2012)
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 (January 2011 - January 2012)
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-December 2012)
WPC improvement over MOS Brier score, including percentage of stations adjusted, for Days 3-7 PoP fcsts


Monthly Performance Charts - 12-Hour PoP (January 2012 - January 2013)
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 (January 2013)
Note:  MAE = Mean Absolute Error
 
Forecasts prepared by WPC meteorologists
MOS/WPC/NDFD Minimum Temperature 
(Days 4-7) 		MAE Bias
MOS/WPC/NDFD Maximum Temperature 
(Days 4-7) 		MAE Bias
MOS/WPC/NDFD 12-Hour PoP 
(Days 4-7) 		Brier Score

Products derived from forecasts prepared by WPC meteorologists
MOS/WPC/NDFD Dew Point Temperature 
(valid every 6 hours from F90-F180) 		MAE Bias
MOS/WPC/NDFD Wind Speed 
(valid every 6 hours from F90-F180) 		MAE Bias
MOS/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

NOAA/ National Weather Service
National Centers for Environmental Prediction
Weather Prediction Center
5830 University Research Court
College Park, Maryland 20740
Weather Prediction Center Web Team		 Disclaimer
Credits
Glossary
 Privacy Policy
About Us
Career Opportunities
Page last modified: Tuesday, 05-Mar-2013 18:05:51 UTC