Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
123 AM EDT Mon Jul 02 2018
Valid 12Z Thu Jul 05 2018 - 12Z Mon Jul 09 2018
...Overview and weather threats/highlights...
A closed upper high will settle into the Rockies by the weekend as
upper troughing over Canada dips into New England by Saturday,
bringing in cooler temperatures (back near average). Much of the
west and central states will see an increase in warmth with above
average heights over the entire lower 48 even under troughing in
the east. Precipitation will generally focus around the upper high
from the Pacific Northwest (in conjunction with an offshore
weakening upper low) and across the northern tier into the
Northeast as well as on the south side of the upper high across
the Gulf Coast where temperatures will be near or just below
average. By the weekend, precipitation should precede the front
southeastward into the Mid-Atlantic, Southeast, and lower
Mississippi Valley.
...Guidance evaluation/preferences...
The latest model/ensemble guidance remained in excellent agreement
with the track of the upper high and good agreement with the
features around it. Given some run-to-run shifts in timing/track
of these features, a multi-model blend was utilized for days 3-5
with an increased weighting of ensembles by the weekend into next
week. This maintained good continuity from the previous shift.
Fracasso
WPC medium range forecasts of 500 mb heights, surface systems,
weather grids, quantitative precipitation, and winter weather
outlook probabilities are found at:
http://www.wpc.ncep.noaa.gov/medr/5dayfcst500_wbg.gif
http://www.wpc.ncep.noaa.gov/medr/5dayfcst_wbg_conus.gif
http://www.wpc.ncep.noaa.gov/5km_grids/5km_gridsbody.html
http://www.wpc.ncep.noaa.gov/qpf/day4-7.shtml
http://www.wpc.ncep.noaa.gov/wwd/pwpf_d47/pwpf_medr.php?day=4