- Day Three
acus03 kwns 070727
Storm Prediction Center ac 070726
Day 3 convective outlook
National Weather Service Storm Prediction Center Norman OK
0226 am CDT Tuesday Jul 07 2015
Valid 091200z - 101200z
..no severe thunderstorm areas forecast...
the risk of severe thunderstorms across the U.S. On Thursday
currently appears negligible.
While its center continues to shift westward...inland across the
southeastern states...subtropical ridging also appears likely to
expand westward across the lower Rio Grande Valley and adjacent
areas of northern Mexico...and northward through the southern and
Central Plains. At the same time...models continue to suggest that
a closed low...within the southern branch of split middle-latitude
westerlies...will slowly accelerate inland of California coastal
areas...northeastward across the Sierra Nevada into the Great
Basin...as a strong upstream jet noses across the north central and
northeastern Pacific. Downstream short wave ridging may build in
phase with the subtropical ridging to the southeast...through much
of the northern plains.
Models currently suggest only sufficient moisture for generally weak
destabilization. At this time...this appears to preclude an
appreciable risk for severe thunderstorms...but middle/upper forcing
for large-scale ascent should still contribute to scattered to
numerous thunderstorms on Thursday.
..east of rockies...
A lingering frontal zone extending from the middle Atlantic coast
through parts of the Ohio and middle Mississippi valleys into the
Central Plains is expected to provide one focus for scattered
thunderstorm activity. Sea breezes along the central/eastern Gulf
Coast likely will provide another...beneath the subtropical high.
While the front will remain to the south of the stronger
middle-latitude westerlies...a convectively enhanced perturbation
emerging from the Southern Plains may be accompanied by a belt of
modest deep layer westerly winds as it progresses around the
periphery of the subtropical ridge...across the central Appalachians
and northern middle Atlantic coastal areas. With Lower/Middle
tropospheric lapse rates expected to remain weak beneath a warm
middle-level environment...appreciable severe weather potential is
still uncertain at the present time.
Meanwhile...along the frontal zone across the plains...a
strengthening nocturnal southerly low-level jet could support
vigorous thunderstorm development across parts of eastern Kansas
into western Missouri Thursday evening. But severe weather
potential remains unclear at the present time due to the presence of
a warm middle-level environment with only weak to modest middle-level
lapse rates...and generally weak middle/upper flow.