SPC MD 1565

Facebook Twitter Google+

MD 1565 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR LOWER GREAT LAKES REGION/ST. LAWRENCE VALLEY AND ADJACENT NEW YORK STATE Mesoscale Discussion 1565 NWS Storm Prediction Center Norman OK 1148 PM CDT Mon Aug 24 2020 Areas affected…Lower Great Lakes region/St. Lawrence Valley and adjacent New York state Concerning…Severe potential…Watch unlikely Valid 250448Z – 250645Z Probability of Watch Issuance…20 percent SUMMARY…A line of thunderstorms may continue to develop and strengthen while spreading across the lower Great Lakes region and adjacent portions of the upper St. Lawrence Valley. While this activity may pose a risk for hail and gusty winds as it spreads into portions of western and northern New York state by 4-6 AM, it may remain generally below severe limits. A severe weather watch currently appears unlikely, but trends will continue to be monitored. DISCUSSION…In advance of a significant, digging short wave trough, scattered thunderstorms have recently initiated over southern Ontario. Activity is in the process of increasing, near or just ahead of an initial southeastward advancing cold front. A narrow corridor of seasonably high boundary-layer moisture (upper 60s to around 70 F surface dew points) appears to be contributing to mixed-layer CAPE up to around 1500 J/kg, despite somewhat modest initial mid-level cooling. This air mass is forecast to advect southeastward across the lower Great Lakes region and adjacent St. Lawrence Valley vicinity, into portions of western and northern New York state through 08-10Z. Coupled with ongoing modest strengthening of cyclonic deep-layer west-northwesterly mean flow (to around 30-35 kt), the environment may be conducive to further upscale growth and organization of convection, with the potential to produce small to marginally severe hail, and at least locally strong surface gusts which may approach severe limits. ..Kerr/Grams.. 08/25/2020 …Please see www.spc.noaa.gov for graphic product… ATTN…WFO…BTV…ALY…BGM…BUF… LAT…LON 45147702 45537503 44557399 42887687 42647898 42798040 43917976 45147702 Read more
SPC Mesoscale Discussions