About the Medium Range Forecast
Issuance Times
(updated May 28, 2013)

Product Time
Day 3-7 500mb Height Forecasts 0200 UTC and 1400 UTC
Day 3-7 Fronts/Pressure Graphics for North America 0330 UTC and 1500 UTC
Day 3-7 Fronts/Pressure Graphics for the Northern Hemisphere 2030 UTC
Day 3-7 Min/Max/PoPs 0515 UTC and 1430 UTC
CONUS Grids 0600 UTC and 1530 UTC
Forecast Discussion 0700 UTC and 1600 UTC
Day 4-5 and Day 6-7 48-hour QPFs 0830 UTC and 1930 UTC

About These Products

The medium range graphical forecast products include: The surface pressure and fronts graphics are generated three times per day; the 0330 UTC and 1500 UTC issuances display features over the continental U.S. (CONUS) only, while the 2030 UTC issuance includes fronts and surface pressure fields for much of the Northern Hemisphere. The 500mb forecasts and Min/Max/PoP graphics are primarily focused on the CONUS and issued twice per day.

In addition to the graphical forecasts, the forecasters prepare two daily written discussions. They highlight medium-range model differences, provide weather solution preferences, a measure of uncertainty, forecaster reasoning and highlight any significant weather expected to impact the CONUS during the Day 4-7 time frame. Forecasters also provide a separate discussion describing guidance differences and preferences across Hawaii by 1230 UTC.

One meteorologist works during the overnight hours (0000-0900 UTC), while two prepare the forecasts during the day shift (1130-2030 UTC). The overnight forecaster generates a set of North American 3-7 day pressure systems/fronts and 500mb forecasts, 3-7 day sensible weather grids, two 48-hour QPFs, and discussion. During the day shift, the two meteorologists collaborate to generate a new set of these same medium range products along with Northern Hemisphere 3-7 day pressure systems/fronts, targeted observation guidance, and the Hawaiian discussion. They routinely use output from the GFS, ECMWF, and UKMET medium range models and also consider the Canadian, the Navy's NAVGEM model, and ensemble guidance from the GFS, ECMWF, Canadian, and North American Ensemble Forecast System (NAEFS).

In addition, during hurricane season, at 1700 UTC on a daily basis since June 1, 1997, the medium range pressure dayshift forecaster also participates in a conference call with the NHC via the Hurricane Hotline to discuss current and potential tropical activity in the Atlantic and Eastern Pacific oceans and how the medium range models are handling the situation.