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SPC - No watches are valid as of Tue May 17 13:59:02 UTC 2022
No watches are valid as of Tue May 17 13:59:02 UTC 2022.
SPC MD 799
MD 0799 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR CENTRAL/EASTERN NE...FAR WEST-CENTRAL IA
Mesoscale Discussion 0799 NWS Storm Prediction Center Norman OK 0856 AM CDT Tue May 17 2022 Areas affected...Central/Eastern NE...Far West-Central IA Concerning...Severe potential...Watch unlikely Valid 171356Z - 171600Z Probability of Watch Issuance...20 percent SUMMARY...Isolated hail possible across central and eastern NE this morning. DISCUSSION...A robust elevated thunderstorm continues over northeast NE, although some modest updraft weakening has been noted recently. This thunderstorm developed on the far eastern edge of the steep lapse rate plume and at the nose of the modest low-level jet. Some limited ascent may have also been provided by a weak shortwave trough moving into the central Plains. Some additional thunderstorms have initiated farther west across central NE, although these updrafts are not as intense as the northeast NE storms yet. Deep cumulus exists all the way into far southwest NE. Low-level stability remains in place within the downstream air mass, although diurnal heating will weaken convective inhibition with time. Even so, current observational trends and mid-level moistening noted within forecast soundings suggest these area of storms could persist. Severe coverage is currently expected to remain isolated, limiting the need for a watch in short-term, but observational trends will be monitored closely. ..Mosier/Grams.. 05/17/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DMX...FSD...OAX...GID...LBF... LAT...LON 41870071 42379796 42519691 42469613 42169554 41879538 41439544 41189590 40719660 40379728 40159836 40350003 41870071Read more
SPC May 17, 2022 1300 UTC Day 1 Convective Outlook
SPC 1300Z Day 1 OutlookDay 1 Convective Outlook NWS Storm Prediction Center Norman OK 0739 AM CDT Tue May 17 2022 Valid 171300Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS EVENING INTO TONIGHT FROM EASTERN NE TO NORTHEAST KS...SOUTHWEST IA...AND NORTHWEST MO... ...SUMMARY... Scattered very large hail in excess of 2 inches in diameter, damaging thunderstorm winds to 70 mph, and a couple of tornadoes will be possible this evening into tonight from eastern Nebraska into northeast Kansas, southwest Iowa, and northwest Missouri. ...NE/KS/MO late this afternoon into tonight... A complex, largely zonal flow regime with subtle embedded speed maxima will affect the central CONUS through tonight. A weak southern stream trough will drift eastward over NM/southern CO, while a downstream MCVs from overnight convection move eastward from OK/KS to MO/AR today. The primary feature of interest this period is a subtle trough over WY/MT early this morning that will crest the flat ridge over the High Plains and progress east-southeastward to the middle MO Valley this evening into tonight. Associated lee cyclogenesis is expected today near the CO/KS border, and the remnant lee cyclone will develop south-southeastward toward the TX Panhandle tonight as a cold front moves southeastward across CO/NE/KS. Some temporary disruptions to the low-level moisture field have occurred overnight across OK in the wake of weakening convection and the MCVs with heat bursts, but this drying should wane as storms dissipate. Thereafter, a corridor of mid 60s boundary-layer dewpoints will establish across eastern KS into southeast NE by this evening. When the cold front intercepts the richer moisture and larger buoyancy by late evening from northeastern NE into northern KS, thunderstorm development is expected. Storms will subsequently spread southeastward overnight into the corridor of richer moisture and MLCAPE of 2000-3000 J/kg, aided by warm advection on the nose of a 30-40 kt low-level jet. The large buoyancy and steep midlevel lapse rates/large DCAPE will favor precipitation-loaded downdrafts capable of producing wind damage. Profiles will also potentially favor very large hail, though this threat depends largely on maintaining supercell structures within the larger area of convection. Any tornado threat will likely depend on at least mid 60s dewpoints making it into NE, and on maintaining semi-discrete supercells into late evening, or with line-embedded mesovortices. ...Southeast WY to the southeast TX Panhandle this evening... A few high-based thunderstorms will be possible this afternoon/evening in association with surface heating/deep mixing and the influences of a shortwave trough crossing WY, and a southern stream trough moving eastward from NM/CO. Any storms/clusters that form in this corridor will be capable of producing isolated severe outflow gusts for a few hours late this afternoon/evening, given inverted-V profiles. ..Thompson/Leitman.. 05/17/2022Read more