SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0248 PM CDT Sun Sep 26 2021 Valid 262000Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING ACROSS PARTS OF SOUTHEAST AZ/SOUTHWEST NM... ...SUMMARY... Isolated severe hail and/or gusts remain possible this afternoon and evening across southeast Arizona and southwest New Mexico. ...20Z Update... No changes have been made to the Marginal Risk area across parts of southeast AZ and southwest NM. Around 500-1000 J/kg of MLCAPE has developed across this area, with modestly enhanced mid-level winds supporting 20-30 kt of effective bulk shear. Isolated instances of marginally severe hail and strong/gusty winds should remain the primary severe threats with any of the stronger storms through the remainder of the afternoon and continuing into the early evening. ..Gleason.. 09/26/2021 .PREV DISCUSSION... /ISSUED 1115 AM CDT Sun Sep 26 2021/ ...Synopsis... A closed midlevel low over the northern Gulf of CA will move slowly eastward near the southern AZ border through tonight. Surface heating in cloud breaks across southeast AZ/southwest NM, and ascent northeast of the midlevel low will support scattered thunderstorm development this afternoon into this evening. Moderate buoyancy (MLCAPE near 1000 J/kg) and effective bulk shear of 25-30 kt will support the potential for a few semi-organized storm clusters. Isolated strong outflow gusts will be possible with the stronger storms given steepening low-level lapse rates. Though lapse rates aloft will not be particularly steep, the moderate buoyancy and vertical shear may support isolated, marginally severe hail. Otherwise, isolated lightning flashes will be possible through mid afternoon with elevated convection over eastern ME with an ejecting shortwave trough. A few thunderstorms are expected this afternoon across southwest FL with a weak backdoor cold front and local sea breeze circulations. Overnight, isolated lightning flashes may occur with weak elevated convection in the warm conveyor belt over northwest WA, immediately in advance of a midlevel trough and baroclinic zone moving eastward over the southeast Gulf of Alaska. Read more LIVE: spc.noaa.gov
http://dlvr.it/S8P1Wy
