California Applications Program

Historical Medium Range Forecast (MRF) Ensemble Project

Last update: 11 July 2003
NPACI Online article "Improving Predictions of Extreme Climate Events" showcases CAP Project
Description Progress Variables
Description
The CAP historical MRF ensemble project uses a global atmospheric model to make a set of daily medium range (0-14 day) forecasts (MRFs) over a reasonably long historical period. This MRF history can then be used to gauge forecast skill and assess predictability of various kinds of weather events. Every day from 1979 to the present we will be making an ensemble of 10 forecasts.

The model we are using is the National Centers for Environmental Prediction (NCEP)'s MRF model (Reanalysis II version).

To produce an ensemble of 10 forecasts we have adopted the NCEP "breeding" procedure to make 5 pairs of positively and negatively perturbed initial conditions for each of the individual forecast runs.

This work was partially supported by National Computational Science Alliance under SIO237 and utilized the SDSC T90 and UT SV1.

Progress
As vector resources diminish, we are completing the vector phase of this project. Runs now exist for September 1982 through December 1989. Plans are to continue runs from January 1990 through 1993 as time permits. The next phase of the project will be to use a parallel code for similar simulations.

The short-term goal is to complete 10 simulations every day during 4 ENSO periods.
The long-term goal is to complete 10 simulations every day from 1979 to the present.

The table below shows our current progress.

Green: Completed CAP 10-member MRF
Light Green: Currently running by CAP 10-member MRF
Light Red: Have NCEP MRF forecasts (17 member ensemble)
Red: Have NCEP MRF forecasts and CAP hindcasts

Medium Range (0-15 day) Global Historical Forecast Archive

YEAR
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
2003 - - - - - -
-
-
-
-
-
-
2002 - - - - - - - - - - - -
2001 - - - - - - - - - - - -
2000 - - - - - - - - - - - -
1999 - - - - - - - - - - - -
1998 - - - - - - - - - - - -
1997 - - - - - - - - - - - -
1996 - - - - - - - - - - - -
1995 - - - - - - - - - - -
1994 - - - - - - - - - - - -
1990 - - - - - - - - - - - -
1989 - - - - - - - - - - - -
1988 - - - - - - - - - - - -
1987 - - - - - - - - - - - -
1986 - - - - - - - - - - - -
1985 - - - - - - - - - - - -
1984 - - - - - - - - - - - -
1983 - - - - - - - - - - - -
1982 - - - - - - - - - - - -

- CAP runs completed
- CAP current runs
- NCEP forecasts
- CAP runs and NCEP forecasts

Variables
Each forecast is run for 15 days (360 hours). Model output is saved every 12 hours. From these output files, a subset of variables are extracted and saved locally in GRIB format. The variables being saved locally are listed below. Some variables are saved on the model grid (T62 or 192 longitudes by 94 latitudes) and some variables are saved on an even 2.5 degree resolution grid (for a global array of 144 longitudes by 73 latitudes). Variables denoted as FLUX are on the T62 grid and variables denoted as PGB are on the 144x73 grid.
Variable Abbreviation Units Grid
Absolute Vorticity at 500mb ABSV:500 1/s PGB
Albedo ALBDO % FLUX
Convective Precipitation Rate CPRAT kg/m^2/s FLUX
Downward Longwave Flux DLWRF W/m^2 FLUX
Downward Solar Radiation Flux DSWRF W/m^2 FLUX
Geopotential Height at 1000mb HGT:1000 gpm PGB
Geopotential Height at 200mb HGT:200 gpm PGB
Geopotential Height at 250mb HGT:250 gpm PGB
Geopotential Height at 500mb HGT:500 gpm PGB
Geopotential Height at 700mb HGT:700 gpm PGB
Geopotential Height at 850mb HGT:850 gpm PGB
Latent Heat Flux at the Surface LHTFL W/m^2 FLUX
Potential Evaporation Rate PEVPR W/m^2 FLUX
Precipitation rate PRATE kg/m^2/s FLUX
Mean Sea Level Pressure PRES:MSL Pa PGB
Precipitable water in the atmospheric column PWAT kg/m^2 FLUX
Relative Humidity at 1000mb RH:1000 % PGB
Relative Humidity at 500mb RH:500 % PGB
Relative Humidity at 700mb RH:700 % PGB
Relative Humidity at 850mb RH:850 % PGB
Relative Humidity at 925mb RH:925 % PGB
Runoff at the surface RUNOF kg/m^2 FLUX
Sensible Heat Flux at the Surface SHTFL W/m^2 FLUX
Specific Humidity 2m above the ground SPFH kg/kg FLUX
Total Cloud Cover in the atmospheric column TCDC % FLUX
Maxium Temperature 2m above the ground TMAX K FLUX
Minimum Temperature 2m above the ground TMIN K FLUX
Temperature at 200mb TMP:200 K PGB
Temperature at 250mb TMP:250 K PGB
Temperature 2m above the ground TMP:2 K FLUX
Temperature at 500mb TMP:500 K PGB
Temperature at 700mb TMP:700 K PGB
Temperature at 850mb TMP:850 K PGB
Temperature at the surface TMP:SFC K FLUX
Zonal Momentum Flux at surface UFLX N/m^2 FLUX
Zonal (u) Wind at 200mb UGRD:200 m/s PGB
Zonal (u) Wind at 250mb UGRD:250 m/s PGB
Zonal (u) Wind at 500mb UGRD:500 m/s PGB
Zonal (u) Wind at 700mb UGRD:700 m/s PGB
Zonal (u) Wind at 850mb UGRD:850 m/s PGB
Zonal (u) Wind at 10m above the ground UGRD m/s FLUX
Upward Long Wave Radiation Flux at the Surface ULWRF:sfc W/m^2 FLUX
Upward Solar Radiation Flux at the Surface USWRF W/m^2 FLUX
Meridional Momentum Flux at the Surface VFLX N/m^2 FLUX
Meridional (v) Wind at 200mb VGRD:200 m/s PGB
Meridional (v) Wind at 250mb VGRD:250 m/s PGB
Meridional (v) Wind at 500mb VGRD:500 m/s PGB
Meridional (v) Wind at 700mb VGRD:700 m/s PGB
Meridional (v) Wind at 850mb VGRD:850 m/s PGB
Meridional (v) Wind at 10m above the ground VGRD m/s FLUX
Pressure Vertical Velocity at 500mb VVEL:500 Pa/s PGB
Accumulated Snow Depth WEASD kg/m^2 FLUX

Relevant Links

California Applications Program (CAP)
NCEP Reanalysis2 Page
NCEP Ensemble Products
This page will be updated monthly as progress continues on our CAP Historical Hindcast Ensemble Project.
If you have comments or suggestions, please send email to Mary Tyree: mtyree@ucsd.edu