About the Medium Range Forecast

Issuance Times

(updated January 24, 2020)

Product	Time
Day 3-7 500mb Height Forecasts	0200 UTC and 1400 UTC
Day 3-7 Fronts/Pressure Graphics for North America	0430 UTC and 1630 UTC
Day 3-7 Fronts/Pressure Graphics for the Northern Hemisphere	2130 UTC
Day 3-7 Min/Max/PoPs	0400 UTC and 1600 UTC
CONUS Grids	0400 UTC and 1600 UTC
Forecast Discussion	0700 UTC and 1900 UTC
Day 4, 5, 6, and 7 24-hour QPFs	0400 UTC and 1600 UTC
Day 4-7 Winter Weather Outlook	0500 UTC and 1700 UTC

About These Products

The medium range graphical forecast products include:

Surface pressure patterns, circulation centers, fronts, and 500mb heights for days 3-7 into the future
Daily maximum and minimum temperatures and anomalies for days 3-7
Daily precipitation probabilities for days 3-7
Four 24-hour QPFs encompassing days 4-7
5-Day Total QPF for Days 1-5 and a 7-Day Total QPF for days 1-7
Winter Weather Outlooks for Days 4, 5, 6, and 7

The surface pressure and fronts graphics are generated three times per day; the 0430 UTC and 1630 UTC issuances display features over the continental U.S. (CONUS) only, while the 2130 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.

The workflow consists of three shifts per day. Two meteorologists focus on the contiguous U.S., one during the overnight hours (0000-0900 UTC) and one on the day shift (1130-2030 UTC). They generate a set of North American 3-7 day pressure systems/fronts and 500mb forecasts, 3-7 day sensible weather grids, four 24-hour QPFs covering Days 4-7, winter weather outlooks for Days 4-7, and a discussion. In addition, the overnight forecaster prepares a Hawaiian discussion focusing on numerical forecast guidance and significant weather threats. The third meteorologist, who works from 1500-0000 UTC primarily focuses on Alaskan forecasting. See the Alaska Medium Range product information section for more details. All forecasters 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.