Important: The Climate Analysis Branch (PSD1) web site will be down in anticipiation of our major web restructuring starting Tuesday Jan 20th at 1pm MST.
You can find more info about the upcoming URL changes here.
You can find more info about the upcoming URL changes here.
Experimental Pentad 2 Forecast
Products
NEW:  Operational NCEP products derived from the CDC ensemble
NEW:  Probabilistic precip forecasts downscaled to 32 km resolution using forecast analogs
These forecast products are derived from an experimental
real-time ensemble run at CDC. A 15-member ensemble is run every day
at 00 UTC using a frozen version of the operational MRF, which was operational
between January and June 1998. Forecasts with the same model and ensemble configuration
are being run retrospectively for every day from November 1978 to the present as part of the MRF Reforecast Project.
Having a sufficiently long historical
dataset of forecasts with the same model used to produce the real-time ensemble
will allow us to correct for model systematic errors and calibrate forecast
probabilities more accurately than can be done with the operational NCEP ensemble.
Download recent real-time forecast data and station forecasts here.
Download historical re-forecasts (197811-200212) here.
The forecast plots are displayed as follows:
Five fields are currently available (500 mb height, 250 mb zonal wind, 850 mb temperature, sea-level pressure and precipitation).
Anomalies and terciles are relative to a 1979-2001 daily climatology (smoothed with a 31-day running mean). Forecast anomalies are calculated relative to the climatology of the forecast model (i.e the mean bias is removed). Tercile probabilities are calculated using the retrospective forecast database (see here for a description of the method) and are generally quite reliable (as evidenced by the cross-validated forecast verification statistics).
For more information, see the manuscript submitted to Monthly Weather Review.
Download recent real-time forecast data and station forecasts here.
Download historical re-forecasts (197811-200212) here.
The forecast plots are displayed as follows:
Lower tercile
probability |
Upper tercile
probability |
Climatological Lower Tercile |
Climatological Upper Tercile |
Ensemble Mean Forecast Anomaly |
Verifying (CDAS) Anomaly - when available |
Five fields are currently available (500 mb height, 250 mb zonal wind, 850 mb temperature, sea-level pressure and precipitation).
Anomalies and terciles are relative to a 1979-2001 daily climatology (smoothed with a 31-day running mean). Forecast anomalies are calculated relative to the climatology of the forecast model (i.e the mean bias is removed). Tercile probabilities are calculated using the retrospective forecast database (see here for a description of the method) and are generally quite reliable (as evidenced by the cross-validated forecast verification statistics).
For more information, see the manuscript submitted to Monthly Weather Review.