SPC May 17, 2022 0100 UTC Day 1 Convective Outlook

 SPC AC 170059 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 PM CDT Mon May 16 2022 Valid 170100Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CAROLINAS...NEW ENGLAND AND SOUTHERN HIGH PLAINS... ...SUMMARY... Isolated large hail and damaging winds will be possible this evening along parts of the Atlantic Seaboard into the northern Appalachians. Damaging wind gusts and isolated large hail will also be possible in parts of the southern High Plains this evening. ...Carolinas/Mid-Atlantic... Latest surface analysis has a cold front in the southern Appalachian foothills with a pre-frontal trough located from central South Carolina into east-central North Carolina. Ahead of the trough, an axis of moderate instability is present, where MLCAPE ranges from 1000 to 1500 J/kg according to the RAP, and surface dewpoints are in the 65 to 70 F range. At mid-levels, a trough is moving through the central Appalachians, with a jet max in the base of the trough. This mid-level speed max is creating moderate deep-layer shear across much of North Carolina. The Raleigh WSR-88D VWP has 0-6 km shear near 50 knots, which should support isolated supercell development over the next hour or two. Large hail and wind damage will be possible with the stronger updrafts. Multicell line segments with wind damage potential will also be possible. The severe threat should be considerably less over South Carolina, where deep-layer shear is relatively weak. The threat is expected to become more isolated later this evening as instability drops across the Carolinas. ...New England... The latest surface analysis has a 994 mb low over far southern Quebec with a pre-frontal trough extending southward across far eastern New York. Ahead of the trough, surface dewpoints are near 60 F, and an axis of weak instability is present across much of New England. Water vapor shows an upper-level trough over the lower Great Lakes, with a band of strong large-scale ascent ahead of the trough in western New England. Thunderstorms are ongoing to the east of the band from western Maine into far eastern Massachusetts. Concerning the shear environment, the WSR-88D VWP near Portland, Maine has 0-6 km in the 40 to 45 knot range. This combined with the weak instability and strong forcing, suggests that a marginal severe threat could continue early this evening. Strong wind gusts and hail will be the primary threats. ...High Plains... The latest water vapor imagery has an upper-level ridge over the central and northern Rockies. At the surface, the western edge of a relatively moist airmass is located from eastern New Mexico, northward into western Nebraska and northwestward into southern Montana. Isolated to scattered thunderstorm development will likely continue this evening along this corridor. The strongest thunderstorms will be located in the southern High Plains, where the RAP has moderate instability. MLCAPE from eastern New Mexico into the Texas Panhandle is estimated to be in the 1000 to 2000 J/kg range. In addition, the WSR-88D VWP at Amarillo has veering winds with height in the lowest 3 km above ground level with 0-6 km shear near 40 knots. This combined with very steep low-level lapse rates will be favorable for damaging wind gusts, associated with supercells and line segments. As cell coverage increases across the southern High Plains this evening, the wind damage threat may increase as an MCS gradually organizes. A few wind gusts over 65 knots will be possible along the leading edge of the MCS. ..Broyles.. 05/17/2022 CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z 

Original News Source Link – National Weather Service

Leave a Comment