Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
300 PM EDT Sat Mar 26 2022
Valid 12Z Tue Mar 29 2022 - 12Z Sat Apr 02 2022
...A deepening low pressure system presents a mid-late next week
heavy rain/severe weather threat across the South while heavy
snow/ice and high wind threat focus across the Upper Midwest/Great
Lakes...
...Overview...
A rapidly intensifying cyclone is forecast to track across the
central/southern Plains through the Great Lakes mid-late next
week. The unsettled and wet pattern initially over the Southwest
will be followed by an outbreak of heavy rain and severe weather
to sweep across the southern tier states through Thursday.
Meanwhile, heavy snow and ice are forecast for the upper
Midwest/upper Great Lakes region where high winds are also
expected. The high winds could also extend well to the west of
the low track across much of the northern and central Plains.
...Guidance Evaluation/Predictability Assessment...
Model guidance this morning has come into general agreement for a
rapidly intensifying cyclone to track across the central/southern
Plains through the Great Lakes mid-late next week under an
upper-level pattern that favors phasing of the cold northern
stream flow with a resurgence of moist southern stream flow from
the Gulf of Mexico. A composite blend of 40% 00Z ECMWF/EC mean,
40% 06Z GFS/GEFS and 20% from the 00Z CMC/CMC mean was used to
compose the Days 3-6 forecasts. Toward the end of next week,
models begin to diverge regarding the amplitude of next upper
trough forecast to dive across the western U.S. The CMC was most
enthusiastic with the trough amplification while the GFS/GEFS
indicated a much flatter evolution. The ECMWF/EC mean was in
between these extremes. An intermediate solution was adopted for
Day 7 by incorporating a higher weighting from the ensemble means.
The solutions maintained very good continuity with the previous
WPC forecast package.
...Weather Highlights/Threats...
An upper low ejecting across southern CA/Southwest will support a
spread of enhanced rain and higher elevation snow through the
south-central Intermountain West/Rockies and the Southwest
Tuesday. As a surface low pressure system strengthens in the
Plains and tracks northeast, increasingly widespread rain and
threat for severe weather with heavy downpours are forecast to
develop over the southern Plains late Tuesday and then move across
the South by Wednesday before reaching the Southeast on Thursday.
The heaviest rains are forecast to break out Tuesday night over
eastern portion of the southern Plains and then sweep through the
Mid-South/Gulf Coast states through Thursday where areas of flash
flooding are possible. An emerging "slight" risk area is depicted
on the new experimental WPC day 5 ERO given favorable system
ingredients and antecedent conditions. Meanwhile, light rain and
some thunderstorms are also expected farther north from the
central Plains through the Mid-Atlantic. On the northern side of
the precipitation shield, the potential for a swath of heavy
wintry mix and accumulating deep low wrapping snows have continued
to increase across the Upper Midwest to the Great Lakes later
Tuesday into Wednesday-Thursday given much model consensus on
developing a rather intense cyclone. High winds appear to likely
impact near and well to the west of the low track during this time
frame as well given the impressive rate of cyclogenesis. Some
wintry precipitation is also forecast for interior New England
late Thursday/early Friday ahead of a warm front, while pockets of
heavy rain are possible down the East Coast ahead of a cold front.
Over the central Rockies to the nearby High Plains, a period of
heavy snow is possible from the central Rockies to the central
High Plains on Tuesday behind a reinforcing cold front. By late
next week, another upper trough is forecast to dig southeastward
from the Pacific Northwest through the western U.S. and could
provide another opportunity for an enhanced round of wintry mix
from the northern to central Rockies to the nearby High Plains.
Some heavy rainfall could linger across the eastern Gulf Coast by
next weekend as a front becomes nearly stationary offshore.
Kong
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
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