SPC AC 240542
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
1242 AM CDT Sat Jun 24 2017
Valid 261200Z - 271200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL
OREGON INTO NORTHWEST IDAHO...
Isolated hail or wind is possible Monday afternoon mainly over
Oregon, and a few strong thunderstorms cannot be ruled out Monday
afternoon across parts of the central and southern High Plains.
A shortwave trough across the Northwest will flatten the northern
Rockies upper ridge and shunt it eastward into the Plains, with a
cold front moving across Oregon. To the east, a larger upper trough
will gradually shift eastward, with rising heights across the
Plains. At the surface, high pressure will remain over much of the
Plains into the east, resulting in relatively stable conditions. The
exception will be across the central and southern High Plains, where
a modestly unstable air mass will develop with heating and 50s to
60s dewpoints slowly spreading northwest. Elsewhere, weak
instability will develop over Oregon and Idaho, in association with
the weak upper wave, and may support scattered strong thunderstorms.
...Oregon into Idaho...
Steep lapses rates will develop with heating, and under the
influence of cooling aloft. Although moisture will be limited,
sufficient instability for thunderstorms will exist, with
development along a weak front. Cool profiles aloft will favor
marginal hail, with areas of strong outflow winds also likely.
...Central and southern High Plains...
Areas of rain and storms may be ongoing across parts of the southern
Plains Monday morning, which may have an effect on destabilization
later in the day. This activity is unlikely to be severe as shear
will be very weak. Redevelopment is expected later in the day across
south central CO into NM, but shear looks to be weaker than on
previous days as the upper trough shifts east. During the evening, a
southerly low-level jet will increase, and this may support isolated
storms from eastern CO into western KS where marginal hail cannot be
ruled out. However, predictability appears too low for a Marginal
Risk at this time.
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NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0730Z