SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0223 AM CDT Mon Apr 18 2022
Valid 201200Z - 211200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS LATE WEDNESDAY
AFTERNOON AND EVENING ACROSS PARTS OF SOUTHEASTERN
KANSAS...SOUTHWESTERN MISSOURI...CENTRAL AND EASTERN
OKLAHOMA....NORTH CENTRAL TEXAS...AS WELL AS PARTS OF WESTERN
OREGON...
...SUMMARY...
A couple of supercells are possible late Wednesday afternoon and
evening, near or east of the Interstate 35 corridor between Kansas
City and the Dallas-Fort Worth Metroplex. A few storms may also
impact areas west of the Oregon Cascades, accompanied by at least
some risk for severe weather.
...Synopsis...
Models indicate little change to the general large-scale pattern
impacting North America through this period, with short waves
remaining progressive within the main belt of westerlies emanating
from the mid-latitude Pacific. This includes one major, and still
amplifying, large-scale trough across the eastern Pacific, which
appears likely to begin advancing inland across the Pacific coast.
Downstream, a significant lead short wave trough is forecast to
migrate across and northeast of the Canadian Maritimes, accompanied
by a relatively deep, occluded surface cyclone. In its wake,
cold/dry surface ridging will maintain considerable influence across
much of the Atlantic seaboard through the northeastern and central
Gulf of Mexico.
The most prominent trailing perturbation across interior North
America is likely to dig within an increasing confluent regime
east-southeast of the central Canadian/U.S. border vicinity toward
the upper Great Lakes. Models indicate little further deepening of
the primary associated surface cyclone, and it may tend to weaken
while migrating from southern Saskatchewan into Ontario. A trailing
cold front appears likely to advance southward through the Upper
Midwest and northern Great Plains by late Wednesday night, preceded
by a surge of cooler air east-southeast of the northern and central
Great Plains into the lower Great Lakes, Ohio Valley, and Ozark
Plateau.
Modest pre-frontal low-level moistening may continue from near the
Mexican Gulf coast northward through the southeastern Great Plains
and middle Mississippi Valley, mostly beneath a plume of warm and
capping elevated mixed-layer air emanating from the southern
Rockies/Mexican Plateau vicinity. This warm mid-level air might
become suppressed across parts of the central Great Plains, before
returning northeastward again in the wake of the short wave trough
passing to the north.
...I-35 corridor from Kansas City to Dallas-Fort Worth...
In the wake of fairly widespread convection and embedded
thunderstorms driven by elevated moisture return within a lower/mid
tropospheric warm advection regime, models indicate that a narrow
corridor of modest boundary-layer based instability may develop
along the trailing cold front and dryline by late Wednesday
afternoon. Mid/upper support for convective initiation remains
unclear, and guidance generally suggests that renewed thunderstorm
development might be widely scattered to isolated. However,
although strong low-level wind fields may be in the process of
shifting east of the region, the environment probably will be
conducive to supercells in the presence of strong deep-layer shear,
accompanied by at least the potential to produce large hail and
locally strong wind gusts.
The cold front/dryline intersection would seem one possible focus
for convective initiation, but considerable spread exists within
model output on where this will end up. And the influence of
possible lingering outflow from the preceding elevated convection is
an added uncertainty. Once these are cleared up, it possible severe
thunderstorm probabilities could still be increased for this period.
...Pacific Northwest...
Models suggest that the weakly unstable warm sector, of a broad and
deep occluded surface cyclone centered over the northeastern
Pacific, may spread inland to the west of the Oregon Cascades during
the day Wednesday. It appears that this will coincide with
mid-level cooling and lift within the exit region of 90+ kt 500 mb
jet nosing onshore, and enlarging, clockwise curved low-level
hodographs near a 40-50+ kt southerly 850 mb jet. And it might not
be out of the question that the environment could become conducive
to low-topped supercells with the potential to produce a tornado,
locally strong wind gusts and/or small hail.
..Kerr.. 04/18/2022
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/SNmrFQ
