Here are a few ensemble-based probabilistic forecast guidance products to glance at for the forecaster in a hurry.  Explore the links at the bottom, if you have the time, as the basic links below only scratch the surface of what is available.

SREF Guidance:  The SREF is a multimodel ensemble, with 10 ETA members, 6 WRF members, and 5 RSM (GFS-like) members run at lower resolution than the operational models with perturbed initial conditions. One can access a suite of probabilistic forecasts on SPC's SREF website.

1. Click on the time next to "Most Recent Model Run." This will either be the current day's 09Z or 15Z SREF run depending on when you are preparing your forecast. This will take you to SPC's SREF interface which will have an extensive menu on the left.

2. Expand the Precipitation submenu, and scroll all the way down till you see "[PR]24hr_total_pcpn_>=Nin." This section gives the probability that the precipitation will exceed N inches during a 24 hour window. For example, clicking on [PR]24hr_total_pcpn_>=0.25in and then moving the cursor to f024 will give the probability that the accumulated precipitation from 0-24hours out will exceed 0.25 inches. You will want to chose the appropriate 24 hour window for our forecast period (f042 for the 09Z SREF and f039 for the 15Z SREF).

SREF Plumes: For a more detailed look at the spread of SREF members, see SPC's SREF Interactive Point Plume & Probability Products. To produce an accumulated precipiation meteogram, select "Total Precipitation (inches)" in the Field menu, hit Submit, then hit Submit again in the second frame down. Choose the current WxChallenge station from the list in the lower-left frame above the map and hit Submit again. A accumulated precipitation ensemble meteogram will appear in the lower-right frame. Likewise, you can create meteograms of 10m wind speed and 2m temperature by choosing the corresponding variable in the Field menu in the topmost frame and repeating.

Additional Links:

SREF:   NCEP    PSU    SPC
GFS:   NCEP Spaghetti    NCEP PQPF    PSU
Canadian
Pacific Northwest MM5
HPC Ensemble Training Page

Original page designed by Jon Moskaitis.
Maintained and modified by Brian Tang.