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 161253
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0753 AM CDT Thu May 16 2019
Valid 161300Z - 171200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
INTO TONIGHT FROM EASTERN WY/NE/IA TO SOUTHERN LOWER MI AND WESTERN
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.
A surface cold front will move southeastward across the upper Great
Lakes in conjunction with a northern stream shortwave trough
crossing ON. The western extent of this front is expected to stall
across IA/NE in response to lee cyclogenesis across the central High
Plains, in advance of deep midlevel trough crossing the Great Basin
and approaching the central/southern Rockies overnight.
...Great Lakes/OH Valley through tonight...
A cluster of elevated storms is ongoing over WI in a zone of strong
low-level warm advection. The surface warm sector will spread
eastward today into IL/IN, possibly reaching southwest Lower MI by
late afternoon. Continuing warm advection will help maintain the
ongoing storms, or contribute to new development later today into
tonight. The stronger storms will occur near the edge of the warm
sector where the convection is rooted closest to the ground, and
storms should be more elevated with eastward extent into OH tonight.
An upstream feed of boundary-layer dewpoints in the low-mid 60s
beneath the northeast edge of an elevated mixed layer plume will
maintain moderate buoyancy, and vertical shear will favor organized
clusters/some embedded supercells along the warm front. Damaging
winds and large hail can be expected with the storm clusters this
afternoon into early tonight, and a tornado or two will also be
possible this evening.
...NE/northern High Plains and northern Rockies this
Easterly upslope flow will be maintained through the period on the
cool side of the stalled front (just N of the lee cyclone), with the
somewhat richer low-level moisture/buoyancy confined mainly to NE.
Gradual height falls in advance of the expansive western trough will
combine with the upslope flow and daytime heating in cloud breaks to
support scattered thunderstorm development this afternoon, which
will persist into this evening. The storm environment will support
a few high-based supercells capable of producing large hail and
strong/damaging outflow gusts, with the greater threat closer to the
NE Panhandle. A similar environment/scenario will extend back into
the northern Rockies of southwest MT and northern ID, along the
northern influence of the Great Basin trough. Overnight, elevated
convection will persist across NE/IA in response to strengthening
warm advection north of the front on the nose of a southwesterly
...Parts of UT/ID this afternoon/evening...
The zone of strongest forcing for ascent in advance of the midlevel
trough and along the cold front will reach western UT and southern
ID later this afternoon through this evening. Though low-level
moisture will be limited, weak buoyancy is expected ahead of the
front. Thunderstorms will be capable of producing isolated
strong/damaging gusts in an environment characterized by weak
buoyancy, steep low-level lapse rates, and strong deep-layer
...Southeast NM and southwest TX this afternoon/evening...
The surface lee trough will sharpen today in response to increasing
southwest flow aloft over the southern Rockies. This area will lie
along the northwest edge of the richer returning low-level moisture,
which will likely be offset today by deep mixing. Still, some
increase in deep-layer shear and sufficient buoyancy suggest that a
couple of high-based supercells will be possible immediately east of
the high terrain in southeast NM into southwest TX late this
afternoon/evening. Marginally severe hail and strong outflow gusts
will be the main threats.
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z