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
- A 48-hour QPF encompassing days 4 through 5
- Total 5-day precipitation for days 1 through 5
The surface pressure and fronts graphics are generated three times per day, while the 500mb forecasts and
Min/Max/PoP graphics are issued twice per day. The 0900 UTC and 1400 UTC sets of graphics are preliminary
and unofficial, intended for inter-office coordination purposes only.
The surface pressure patterns and fronts on the
preliminary forecasts are only drawn for the continental U.S. The final set of
graphics is issued by 1900 UTC, with the surface pressure patterns and fronts encompassing
much of the Northern Hemisphere.
In addition to the graphical forecasts, the forecasters prepare three daily written discussions.
The preliminary narrative highlights medium-range model differences and provides initial model preferences,
and is available by 0900 UTC. This discussion is updated by 1400 UTC to incorporate significant changes
to MOS (Model Output Statistics) and updated global model and ensemble guidance.
The final discussion incorporates the latest model guidance and updates forecast reasoning/model preferences.
In addition, it highlights any significant weather expected to impact the continental U.S.
during the day 4-7 time frame. Forecasters also provide a separate discussion
describing model differences and preferences across Hawaii by 1130 UTC.
One meteorologist works during the overnight hours, while two prepare
the forecasts during the day shift (1030-1930 UTC). The overnight forecaster generates
the initial set of preliminary 3-7 day pressure systems/fronts and discussion due at 0900 UTC.
During the day shift, one of the meteorologists
updates the preliminary forecasts and issues preliminary 500mb height graphics, then, late in the shift,
issues a final discussion and a set of 3-7 day
pressure systems/fronts and 500mb forecasts.
The other forecaster prepares the 5-day precipitation, 3-7 day temperature and PoP progs, and Hawaiian discussion.
They routinely use output from the GFS, ECMWF, and UKMET medium
range models and also consider the Canadian, the Navy's NOGAPS model, and ensemble guidance from
the GFS, ECMWF, Canadian, and North American Ensemble Forecast System (NAEFS).
During hurricane season, at 1200 noon ET time on a daily basis since June
1, 1997, the medium range pressure forecaster 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.