Probability of a tornado within 25 miles of a point. Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
Day 1 Tornado Risk
Area (sq. mi.)
Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Probabilistic Damaging Wind Graphic
Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point. Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
SPC AC 160605
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0105 AM CDT Thu May 16 2019
Valid 161200Z - 171200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL
HIGH PLAINS REGION EASTWARD INTO THE MIDWEST...
Severe storms are possible today and tonight from the central High
Plains eastward into the Midwest region. Isolated strong to severe
storms are also possible from southern Montana through northern
Idaho during the afternoon, across portions of Utah and vicinity,
and across parts of southeast New Mexico and West Texas.
While a couple of upper cyclones over the eastern half of Canada
will maintain a belt of west-northwesterly flow from the northern
Plains across the Great Lakes and Midwest, a more amplified flow
field is progged over the western half of the country. This will
manifest as a result of a trough moving inland from the eastern
Pacific early in the period, impinging upon stout upper ridging
centered over the High Plains. As this system moves inland and
acquires negative tilt with time, widespread convection -- peaking
during the afternoon and evening -- is progged.
Elsewhere, a cold front is forecast to move eastward across the
Great Lakes region, with trailing portions of this front to become
oriented in an increasingly west-to-east manner across the mid
Missouri Valley and Upper Midwest regions through the afternoon and
evening. This front should focus scattered to isolated storm
development during the afternoon, which should then continue through
the evening hours.
...Central High Plains region eastward across the mid Missouri
Valley into the Midwest...
Several episodes of convection are forecast within the west-to-east
slight risk area -- beginning with a band of frontal convection
which should be crossing the Wisconsin/Iowa area early in the
period. As the remnant convection -- and associated cold front --
move into the Midwest during the afternoon, isolated to scattered
storms should re-intensify/redevelop, as the airmass becomes
moderately unstable. With a belt of moderate westerly/northwesterly
flow across this area, storms should move quickly east-southeastward
-- accompanied by the potential for damaging wind gusts along with
large hail. Storms should spread southeastward through the evening,
possibly reaching the central Appalachians late.
Meanwhile farther west, isolated storms should develop over the
western Nebraska/eastern Wyoming vicinity, in an upslope regime just
north of the surface front. While mid-level flow -- within the axis
of the ridge -- should prove to be a bit weak, veering flow with
height should provide sufficient shear for a few strong/locally
severe storms, and attendant risk for hail and locally damaging
winds. Storms should move eastward off the higher terrain during
the evening, with an increase in convection expected near and north
of the surface front as south-southwesterly low-level jet develops
overnight. Primary severe risk would likely be large hail, given
the slightly elevated nature of the overnight storms.
...Parts of northern Idaho across southern Montana...
Large-scale ascent ahead of the upper trough -- focused at the
surface near a baroclinic zone progged to reside from northern Idaho
southeastward across Wyoming -- should support afternoon
thunderstorm development. The convection will be aided by afternoon
heating of a modestly moist boundary layer maintained by easterly
flow just north of the front, thus yielding weak but sufficient
mixed-layer CAPE. With moderately strong mid-level southerly flow
atop the region, shear will be sufficient for organized storms --
particularly just to the cool side of the front where the low-level
easterlies enhance directional shear. Though the modest CAPE should
limit the number of stronger cells, and thus overall severe risk,
locally damaging winds and perhaps a couple of marginally severe
hail events are expected. Though storms will likely continue across
the region into the overnight hours, convection should diminish
below severe levels during the evening.
...Utah and vicinity...
Strong large-scale ascent ahead of the advancing upper trough will
support fairly widespread convective development, as weak
destabilization occurs in conjunction with afternoon heating. As
relatively strong/increasing flow with height spreads eastward
across the area, shear supportive of fast-moving, organized storms
will be present. As such, risk for a few strong/damaging wind gusts
will exist -- primarily during the afternoon and into the evening.
...Southeastern New Mexico into parts of West Texas...
Southeast low-level flow on the western fringe of a southeastern
U.S. high will maintain a feed of low-level moisture across the
Transpecos region of Texas into southeast New Mexico. As diurnal
heating maximizes in the late afternoon, resulting CAPE development
should support initiation of a few storms -- likely initially over
the higher terrain of southeastern New Mexico/West Texas. Though
the magnitude of flow aloft will remain rather modest, veering of
the flow with height may provide sufficient shear for some updraft
rotation, and thus accompanying risk for large hail and/or damaging
wind gusts with a couple of the stronger cells, before convection
dissipates during the evening.
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