Severe Storm Risk - Marshall, MN

There is a Enhanced Severe Storm Risk for your location. Continue reading for today's outlook from the National Weather Service's Storm Prediction Center. -------------------- National Severe Storm Outlook THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN PLAINS SUMMARY Numerous severe thunderstorms with a potential for 60-80 mph winds with locally higher gusts, along with tornadoes (some potentially strong), and large to very large hail are expected across the northern and central Plains this evening into tonight. Central and Northern Plains On water vapor imagery, a mid-level shortwave trough appears to be located from eastern Montana southeastward into western South Dakota and west-central Nebraska. At the surface, a 996 mb low is currently located in northwestern North Dakota with a cold front extending southward from the low. A dryline is evident from central South Dakota into western Nebraska. To the east of the front and dryline, a moist airmass is in place with surface dewpoints in the mid to upper 60s F, which is contributing to moderate to strong instability. Thunderstorms are currently developing along the entire length of the front and dryline. Storms that remain discrete or semi-discrete over the next couple of hours could be supercells, with a potential to produce tornadoes and large to very large hail. A couple of strong tornadoes may occur with supercells that are intense. As convective coverage rapidly increases over the next couple of hours, a transition to linear mode is expected with a squall line forming and moving eastward across the remainder of the Dakotas this evening. Along and near the instability axis, the RAP has 0-3 km lapse rates in the 8 to 8.5 C/km range. In addition, 0-6 km shear near this axis is around 45 knots, as is evident on the Bismarck and Aberdeen WSR-88D VWPs. This environment will be very favorable for severe wind gusts, and some gusts could exceed 80 mph along the more intense parts of the line. While a tornado threat will exist with supercells early on, a continued tornado threat is expected as the squall line develops with embedded rotating cells. The potential for severe wind gusts and tornadoes will continue into the late evening and overnight period as the line moves eastward into the upper Mississippi Valley. Further south into the central Plains, the RAP has a pocket of strong instability analyzed over east-central Nebraska, where the RAP shows MLCAPE in the 4500 to 5500 J/kg range. Severe thunderstorms have developed to the west and south of this instability maximum. The RAP also has a 40 to 50 knot low-level jet max in far northern Kansas. As this feature strengthens and moves northeastward into eastern Nebraska, low-level shear will become increasingly favorable for tornadoes. Supercells that can become robust may be able to produce a strong tornado or two. Southward into central Kansas, strong instability is analyzed by the RAP over much of central and northeastern Kansas, where MLCAPE is estimated to be from 3000 to 4500 J/kg. In addition, moderate deep-layer shear is present and low to mid-level lapse rates are steep. This will support a threat for large hail and severe wind gusts this evening with the stronger supercells and short line segments. Ohio Valley A moist and unstable airmass is currently located across much of the Ohio Valley. An axis of instability is analyzed from southern Illinois east-northeastward across southern Indiana and northwest Ohio. Scattered thunderstorms are ongoing in west-central Indiana just to the west of the instability axis. Ahead of the storms, low-level lapse rates are steep. This will contribute to a potential for isolated severe gusts over the next hour or two.