Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
257 AM EDT Tue Mar 29 2022
Valid 12Z Fri Apr 01 2022 - 12Z Tue Apr 05 2022
...Guidance Evaluation/Predictability Assessment...
The WPC medium range product suite was primarily derived from a
composite of best clustered guidance from the 12 UTC GFS/ECMWF and
GEFS/ECMWF ensemble means along with the 01 UTC National Blend of
Models days 3-5 (Friday-Sunday). Embedded smaller scale system
differences and ample run to run continuity variances remain
problematic despite reasonably similar larger scale pattern
evolutions. Opted to blend just the generally compatible ensemble
means by early next week to mitigate the less predictable forecast
components amid steadily growing forecast spread. Overall, WPC
product continuity is reasonably maintained with this strategy and
the forecast seems in line with a similar composite of newer 00
UTC guidance.
...Overview and Weather Highlights/Threats...
A deep cyclone will eject across a stormy eastern Canada Friday as
high winds and some wrapping snows persist to the lee of the Great
Lakes and across the Northeast on the backside of the cyclone. A
trailing front will sweep off the East Coast, but should stall and
linger over Florida, the Gulf of Mexico/Gulf Coast and into
northern Mexico.
Upstream, a series of progressive upper troughs and frontal
systems forecast to dig with some uncertainty through the West
late week into early next week could each provide an opportunity
for periods of modest wintry weather across the north-central
Intermountain West/Rockies. System progressions downstream within
an emerging southern stream may meanwhile favor modest
precipitation from the central Plains and Midwest to the
Appalachians/Mid-Atlantic, but deeper return moisture focus into
wavy fronts and a stalled lead front offers potential to fuel some
heavy downpours from the Gulf Coast to the Southeast into the
weekend.
By early next week there is also a growing guidance signal to
bring more energetic Pacific jet flow toward the West Coast. This
may transport deeper moisture to fuel and emerging precipitation
pattern focus into the Pacific Northwest to include heavy terrain
enhancing snows.
Schichtel
Additional 3-7 Day Hazard information can be found on the WPC
medium range hazards outlook chart at:
https://www.wpc.ncep.noaa.gov/threats/threats.php
WPC medium range 500mb heights, surface systems, weather grids,
quantitative precipitation, experimental excessive rainfall
outlook, 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/#page=ero
https://www.wpc.ncep.noaa.gov/wwd/pwpf_d47/pwpf_medr.php?day=4
https://www.wpc.ncep.noaa.gov/heat_index.shtml