SPC Day 1 Fire Weather Outlook

By Newsroom America Feeds at 10 Aug 2017

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1144 AM CDT Thu Aug 10 2017 Valid 101700Z - 111200Z With a weak upper low expected to remain over northern CA/southern OR today, the WA Cascades and vicinity have been removed from isolated dry thunderstorm designation, as overall thunder chances in this region now appear to be below 10% through the rest of the period. The isolated dry thunderstorm area has been expanded to include more of northeastern OR, western ID, and eastern WA based on latest short-term model guidance. Northeastern OR into western ID may experience isolated convective development related to differential heating between a think smoke plume centered over eastern WA/northern ID and relatively clear conditions to the south. This region is also forecast to be on the northern periphery of lift associated with the previously mentioned upper low. For additional forecast reasoning regarding the isolated dry thunderstorm area, see the previous discussion below. ..Gleason.. 08/10/2017 .PREV DISCUSSION... /ISSUED 0143 AM CDT Thu Aug 10 2017/ ...Synopsis... A persistent Rex block will remain over the Pacific Northwest today, featuring a weakening low over northern California and a ridge extending northward across British Columbia. Several weak/convectively modulated impulses along the eastern periphery of the aforementioned low will advance east/northeast across the northern Great Basin. Meanwhile, a shortwave trough in weak northwesterly flow will drop southeast from Alberta towards Montana. ...Portions of the Northwest... The previously mentioned features of interest will support pockets of thunderstorm activity across the region once again today. From parts of the Cascades to the northern Great Basin, the weak low at the base of the Rex block (as well as related minor impulses to the east) will encourage convection initially over higher terrain. Meanwhile, the shortwave trough approaching Idaho/Montana will support widely scattered activity progressing south across the Canadian border. Both regimes should be characterized by isolated dry thunderstorms, enhancing the threat of new fire starts and erratic activity. Pockets of scattered total thunderstorm coverage may exist from northern California to southern Idaho, but higher precipitable-water values and/or slow storm motions preclude an upgrade at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more



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