Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
108 AM EDT Sat Nov 02 2019
Valid 12Z Tue Nov 05 2019 - 12Z Sat Nov 09 2019
...Pattern Overview and Guidance/Predictability Assessment...
Overall, the large scale pattern across the CONUS shows slightly
above average predictability during the medium range. A building
ridge from the northeastern Pacific north across Alaska toward the
Arctic will favor a persistent and broad upper trough across the
north central/northeastern U.S.
The WPC medium range product suite was primarily derived from a
composite blend of the quite compatable latest GEFS/ECMWF ensemble
means in lue of reliance on deterministic models that show more
run to run continuity issues with the timings/amplitudes of
embedded weather systems.
...Weather Highlights/Threats...
Broad cyclonic flow aloft will dominate much of the lower 48 next
week as a series of impulses reinforce a central North American
mean upper longwave trough. This trough may gradually shift
eastward as east Pacific upper ridging gradually works inland
across the West Coast. Expect mainly dry conditions for much of
the West except into later next week as Pacific moisture feeds
into/through Pacific Northwest terrain. The downstream pattern
will favor the spread and periodic reinforcement with colder than
normal airmasses from the Rockies and Central U.S. to the East as
post-frontal high pressure cells spill down from Canada. Moisture
will be mainly limited across the mid-higher latitudes, but the
passage of several clipper lows should support modest snows/light
rain swaths over the U.S. northern tier from the Rockies through
the Great Lakes/Northeast where activity will be prolonged by lake
effect. Moisture may sufficiently feed into/over a wavy lead front
to fuel some rains for FL and the coastal Southeast/Carolinas
early next week. Moderate activity may develop and focus mid-later
next week back from the s-central Plains to the mid-lower MS
Valley. Cooled temperatures offer some risk of a light icy coating
on the far northern periphery of the return flow.
Schichtel
Additional 3-7 Day Hazards information can be found on the WPC
medium range hazards chart at:
https://www.wpc.ncep.noaa.gov/threats/threats.php
WPC medium range 500mb heights, surface systems, weather grids,
quantitative precipitation, winter weather outlook probabilities
and heat indices are at:
https://www.wpc.ncep.noaa.gov/medr/5dayfcst500_wbg.gif
https://www.wpc.ncep.noaa.gov/medr/5dayfcst_wbg_conus.gif
https://www.wpc.ncep.noaa.gov/5km_grids/5km_gridsbody.html
https://www.wpc.ncep.noaa.gov/qpf/day4-7.shtml
https://www.wpc.ncep.noaa.gov/wwd/pwpf_d47/pwpf_medr.php?day=4
https://www.wpc.ncep.noaa.gov/heat_index.shtml