Oklahoma City, OK...Cincinnati, OH...Evansville, IN...Norman, OK...Lawton, OK...
Memphis, TN...Nashville, TN...Tulsa, OK...Little Rock, AR...Dayton, OH...
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.
Day 1 Wind Risk
Area (sq. mi.)
Some Larger Population Centers in Risk Area
Oklahoma City, OK...Tulsa, OK...Cincinnati, OH...Lexington-Fayette, KY...Louisville, KY...
Memphis, TN...Fort Wayne, IN...Little Rock, AR...Springfield, IL...Columbia, MO...
SPC AC 281635
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1135 AM CDT Fri Apr 28 2017
Valid 281630Z - 291200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OK TO TN
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SURROUNDING THE
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SOUTHERN GREAT
PLAINS TO CENTRAL APPALACHIANS...
Numerous severe storms are expected today, initially across parts of
the Ohio and Tennessee Valleys this afternoon, and across the
southern Great Plains and Ozarks by tonight. Very large hail,
tornadoes, and damaging winds are anticipated.
Potential exists for multiple severe episodes this afternoon into
tonight across the Enhanced Risk characterized by increasing
moisture, moderate to strong buoyancy, and ample vertical shear.
However, some of this risk is conditional and confidence is below
average in mesoscale details regarding severe coverage.
A mid-level impulse over eastern NE should decay during the period
as an upstream shortwave trough pivots over the Four Corners into
AZ/NM. This will effectively yield rising heights over a large
portion of a poleward-advecting warm sector emanating from the Gulf.
This warm sector will remain characterized by rather rich mean
mixing ratios with upper 60s to middle 70s surface dew points
becoming established from the OH Valley on south as a warm front
passes north through this evening.
Within the low-level warm-advection regime, elevated convection is
ongoing from NE/IA into MO/IL. Additional activity may develop
farther south/east closer to the advancing warm front towards late
afternoon. Low-level hodographs will be comparatively large within
this corridor in conjunction with 40-50 kt 850-mb flow. This setup
could support mixed modes of discrete supercells and upscale-growing
bows capable of tornadoes, large hail, and damaging winds. These
threats will probably remain along and north of the warm front, with
capping increasingly pronounced with southern extent in the warm
...Southern Great Plains to the Ozarks...
Similar to areas farther east, an increasingly rich low-level air
mass is steadily returning, but beneath a more substantial 700-mb
cap. This should inhibit sustained storm development until about
03Z. Along the northwest periphery of the warm sector, a
consolidating surface cyclone over northwest TX amid near-neutral
mid-level height change should result in strengthening frontal
convergence and yield storm development over OK into far northwest
OK. Storm coverage should become widespread overnight along and
north of the quasi-stationary front eastward across the Ozarks.
Supercell-favorable wind profiles and steep mid-level lapse rates
should support several rotating storms with large hail (some
significant) as the primary hazard. Damaging winds and a couple
tornadoes will also be possible, particularly with cells that can be
sustained along the quasi-stationary front. The overall evolution
into a broad clustering band with embedded line segments amid an
anafrontal setup should yield a predominant hail and some wind risk,
continuing on an increasingly isolated basis into the overnight.
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z