Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
330 PM EST Fri Feb 11 2022
Valid 12Z Mon Feb 14 2022 - 12Z Fri Feb 18 2022
...Mid-late week system to bring potential for heavy rain from the
south-central to east-central U.S. and wintry weather from the
Midwest through Great Lakes and interior Northeast...
...Overview...
The dominant focus of the medium range forecast will be on a
potent upper low forecast to enter the Pacific Northwest on
Monday. This feature should drop southeastward along the West
Coast early in the workweek, cross the Southwest around late
Tuesday/Wednesday, and become incorporated into a
Plains/east-central U.S. mean trough by the latter half of the
week. This evolution aloft will lead to surface cyclogenesis and
strong frontal systems in the central U.S., drawing moisture
northward from the Gulf of Mexico and producing notable
precipitation from the Plains eastward next Wednesday into Friday.
Expect rain and thunderstorms in southern areas, while snow and
wintry weather are likely on the northern and western side of the
precipitation shield across the central Rockies/Plains and through
the Midwest, Great Lakes, and interior Northeast.
...Guidance Evaluation/Predictability Assessment...
00Z/06Z guidance remains more agreeable and consistent than
average for the days 3-5 Monday-Wednesday part of the forecast.
Consensus shows a strong East Pacific ridge supporting a
southeastward track for the upper low of interest, from the
Pacific Northwest during the day Monday and reaching the Southwest
by late Tuesday-early Wednesday. Meanwhile upper troughing lifts
away from the East and an initial western U.S. ridge broadens as
it continues eastward. A blend of the GFS/ECMWF/CMC/UKMET from
each model's latest available cycle represented the prevailing
themes of the forecast well. New 12Z runs are similar except for
the CMC that strays weaker/slower with the upper system Tuesday
onward, affecting its forecast farther east through the rest of
the week.
Uncertainty and guidance spread/run-to-run variability increase
somewhat during the latter half of the period. Contributors to the
differences include upstream shortwave energy forecast to drop
into and through the West during mid-late week as well as
important specifics of northern stream flow that may interact with
the leading upper low as it ejects beyond the Rockies/Plains.
These issues will affect the timing, strength, and track of low
pressure as it progresses from near the south-central Plains
northeastward after midweek. In recent runs the GFS has tended to
be a bit on the deeper side of the operational model spread (and
within the deeper part of the GEFS envelope) at some valid times
but has been trending weaker since the 00Z run. The CMC has been
on the weaker/sheared side. For early next Thursday the 12Z UKMET
has come in halfway between the 12Z GFS and 00Z ECMWF for depth.
Meanwhile the ECMWF has trended faster over the past couple days
and the new 12Z run is a bit weaker and farther east versus the
00Z run. Transitioning the 00Z/06Z model blend to include some 06Z
GEFS/00Z ECMWF mean input by days 6-7 Thursday-Friday accounted
for the gradual increase of uncertainty and provided good
continuity in principle. The forecast yielded a modestly stronger
system tracking northeast from the Plains, with additional room
for refinement if confidence increases.
...Weather Highlights/Threats...
The upper low/trough dropping into the West early in the week will
spread an area of precipitation across the region, but totals of
coastal/lower elevation rain and mountain snow should remain light
to moderate. However, widespread showers and thunderstorms are
likely to develop over the central U.S. by Wednesday into Thursday
as surface low pressure consolidates in the High Plains and
advects substantial moisture from the Gulf of Mexico northward
into the Plains, Mississippi/Tennessee/Ohio Valleys, and
eventually the Eastern Seaboard. Strong storms could be possible,
with the current days 6-7 Storm Prediction Center outlook showing
some severe threat from parts of the southern Plains into
Tennessee Valley and vicinity. There will also be flash flooding
concerns where heavy rainfall occurs. Continue to monitor
forecasts as uncertain details of these potential threats become
better refined. At the same time, expect a band of snow in the
colder air on the northwestern periphery of the system. The best
potential for meaningful accumulations currently extends from
central parts of the Plains into the Middle Mississippi Valley and
Midwest/Great Lakes region into interior New England, while mixed
precipitation/ice cannot be ruled out in the transition zone
between the snow and rain. Totals/location of any snow will be
very sensitive to precise strength and track of the system. Strong
winds may be possible in the gradient between the surface low and
high pressure to the northwest, and then possibly along parts of
the East Coast within the southerly flow ahead of the storm.
The change and progression of the overall pattern will be evident
in temperatures over the course of next week. Warmer than average
temperatures across the Central Great Basin and Southwest Monday
will moderate to near normal or slightly below Tuesday and
Wednesday underneath the incoming upper trough/low. West Coast
states should see readings rebound to moderately above normal for
the latter half of the week. Meanwhile a warming trend over the
central U.S. should peak around Tuesday-Wednesday as high
temperatures reach 10-20F above normal both days with lows 15-25F
above normal Wednesday. The system/cold front emerging from the
West will then quickly drop temperatures to 5-15F or so below
normal for Thursday-Friday. Meanwhile the midweek warmth over the
Plains will move into the East for Thursday-Friday with one or two
days of highs up to 10-20F above normal and lows exceeding 20F
above normal over some areas. This will represent a significant
warming trend for the Eastern Seaboard which can expect to start
the week with temperatures 10-20F below normal.
Rausch/Tate
Hazards:
- Heavy precipitation across portions of the southern Plains
through the Midwest and the lower Great Lakes into far interior
New England, Wed-Thu, Feb 16-Feb 17.
- Heavy rain across portions of the southern Plains, much of the
Deep South, the Northeast, through the lower and mid-Mississippi
Valley, as well as the Tennessee and Ohio Valleys and into the
southern Appalachians, Wed-Thu, Feb 16-Feb 17.
- Severe weather across portions of the southern Plains through
the lower and mid-Mississippi Valley toward the Ohio Valley,
Wed-Thu, Feb 16-Feb 17.
- High winds across portions of the central/southern High Plains
toward the upper Midwest, Thu, Feb 17.
- High winds across portions of the New England coastal areas,
Fri, Feb 18.
- Much below normal temperatures across portions of the interior
Northeast and the lower Great Lakes, Mon, Feb 14.
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, 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