SPC MD 1339
MD 1339 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR WESTERN AND CENTRAL NORTH CAROLINA...UPSTATE SOUTH CAROLINA
Mesoscale Discussion 1339 NWS Storm Prediction Center Norman OK 0120 PM CDT Sun Jul 03 2022 Areas affected...Western and Central North Carolina...Upstate South Carolina Concerning...Severe potential...Watch unlikely Valid 031820Z - 032045Z Probability of Watch Issuance...5 percent SUMMARY...Thunderstorms developing over the mountains of western NC will spread east-southeastward into the Piedmont region. The stronger cells will produce brief gusty/damaging winds. A watch is not anticipated at this time. DISCUSSION...Visible satellite and radar imagery show increasing thunderstorms over the mountains of western NC. This activity is expected to increase in coverage through the afternoon as strong heating and dewpoints in around 70F yield MLCAPE values of ~2000 J/kg. Low-level lapse rates will be rather steep today as temperatures ahead of the convection rise into the 90s. However, mid-level lapse rates are weak, and winds through the cloud-bearing layer are generally below 20 knots. Isolated cells across the Piedmont region will pose a risk of locally gusty/damaging winds this afternoon, but the risk of a more organized severe threat appears limited. ..Hart/Grams.. 07/03/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...RAH...RNK...CAE...GSP... LAT...LON 35188265 36228110 36527980 36087945 35587996 35018092 34678216 34618277 34828308 35188265Read more
SPC MD 1338
MD 1338 CONCERNING SEVERE POTENTIAL...SEVERE THUNDERSTORM WATCH LIKELY FOR SOUTHWEST MONTANA
Mesoscale Discussion 1338 NWS Storm Prediction Center Norman OK 0109 PM CDT Sun Jul 03 2022 Areas affected...Southwest Montana Concerning...Severe potential...Severe Thunderstorm Watch likely Valid 031809Z - 031915Z Probability of Watch Issuance...80 percent SUMMARY...Thunderstorms are expected to intensify across southwest Montana this afternoon, with a risk of a few supercells capable of large hail and damaging winds. A severe thunderstorm watch is likely. DISCUSSION...Radar/satellite imagery show a small cluster of thunderstorms over southern Lemhi county ID, along with increasing towering cumulus clouds over the Sawtooth mountains of central ID. This activity is ahead of a shortwave trough over eastern WA/OR that will track northeastward across the region this afternoon and evening. Mid and high clouds are slowly clearing to the east of this activity, which should allow strong heating and destabilization to occur. Rather cool temperatures aloft (-13 to -14C at 500mb) coupled with dewpoints in the low-mid 50s will aid in MLCAPE values over 1000 J/kg in the mountains of southwest MT. Sufficient effective shear values suggest a risk of a rotating storms capable of large hail and damaging wind gusts. Trends are being monitored for watch issuance in parts of the discussion area. ..Hart/Grams.. 07/03/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BYZ...RIW...TFX...PIH...MSO... LAT...LON 44601356 45701425 46221340 46791181 47011035 46110973 45171061 44241237 44601356Read more
SPC MD 1337
MD 1337 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHEAST SDMesoscale Discussion 1337 NWS Storm Prediction Center Norman OK 1224 PM CDT Sun Jul 03 2022 Areas affected...Southeast SD Concerning...Severe potential...Watch unlikely Valid 031724Z - 031900Z Probability of Watch Issuance...20 percent SUMMARY...Some threat for localized hail and damaging wind gusts may persist through early afternoon. DISCUSSION...An isolated strong thunderstorm has recently evolved along the southern periphery of an elevated storm cluster that developed overnight and moved eastward across SD. It appears that this new cell is being sustained along the eastern edge of a buoyancy gradient, in conjunction with steepening midlevel lapse rates and favorable low-level moisture. Recent intensification trends and weakening MLCINH suggest that this storm may be becoming surface based. Modest midlevel westerly flow is supporting effective shear for a surface-based storm of 30-40 kt, so evolution into a supercell appears possible in the short term, with an attendant risk of hail and locally damaging wind gusts. The longevity of this cell remains somewhat uncertain, with rather weak large-scale ascent and most short-term guidance struggling to maintain convection in this area, but the environment is not prohibitive for sustained convection, and this storm may persist into the mid afternoon. Given the isolated nature of the threat and uncertainty regarding storm longevity, watch issuance is considered unlikely in the short term. ..Dean/Grams.. 07/03/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FSD...ABR... LAT...LON 44079912 44259806 44319759 44249707 43629689 43269705 43189764 43309817 43729912 44079912Read more