|Date||HDD||HDD 30Y Climo||HDD 30Y Diff||CDD||CDD 30Y Climo||CDD 30Y Diff||HDD||CDD||HDD||CDD||HDD||CDD|
Q: What is a Gas Weighted Degree Day?
A: Our algorithm factors in over 100 cities in the US and applies a weight to each city based on the population and natural gas usage as outlined by the U.S. Energy Information Administration (EIA). Each city is assigned a percentage with all cities adding up to 100%. Examples of some of the top weighted cities include Houston, Dallas, Miami, New York City, Chicago, and Los Angeles.
Q: What is a Heating Degree Day (HDD)?
A: A heating degree day takes the day's high and low temperature and averages them together. This number is then subtracted from 65 to get the heating degree day. For example Hi: 60F Lo: 40F the average temperature is 50F. 65-50=15 HDD. The higher the HDD value compared to the 30-year climatology the greater the heating demand. When heating demand is significantly greater than average the box will turn blue. If it is significantly less, the box will turn red.
Q: What is a Cooling Degree Day (CDD)?
A: A cooling degree day takes the day's high and low temperature and averages them together. This number is then subtracted from 65 to get the cooling degree day. For example Hi: 80F Lo: 60F the average temperature is 70F. 70-65=5 CDD. The higher the CDD value compared to the 30-year climatology the greater the cooling demand. When the cooling demand is significantly greater than average, the box will turn red. If the cooling demand is significantly less, the box will turn blue.
Q: What climatology do you use?
A: The climatology used is from 1981-2010. The same equation used to determine gas weighted degree days is used based on climatology values to get an "average". This average gives us a basis to measure heating and cooling demand compared to normal.
Q: Why is there empty cells for certain model runs?
A: While a new model run is processing, certain cells will remain empty until that dates data has been processed. Additionally, a few cells will be empty on previous runs for the last day of that model. This is due to the fact we only apply our algorithm for whole days and some newer runs gain an additional day that the previous run does not have data for.
Q: What is the GFS model?
A: The GFS is an American based weather forecasting model. The GFS is the most widely used model data with forecast going out 384hrs. The GFS model updates 4 times a day.
Q: What is the ECMWF model?
A: The ECMWF is a European based weather forecasting model. It is statistically the most accurate weather model. The ECMWF runs two times a day.
Q: What is the ECMWF-Ensemble model?
A: The ECMWF-Ensemble is a European based weather forecasting model. It is made up of 50 members, plus a control member. Each member is given a different set of initial conditions and forecasts out to 360hrs. We then average all 51 members to form a mean.
Q: When is the model processing schedule?
A: The schedule for each of the models we currently
process are as follows:
00z - 10:30 pm EST
06z - 4:30am EST
12z - 10:30am EST
18z - 4:30 pm
00z - 12:45am EST
12z - 12:45pm EST
00z - 2:40am EST
12z - 2:40pm EST