260 ACUS02 KWNS 260643 SWODY2 SPC AC 260642 Day 2 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0142 AM CDT Thu Apr 26 2018 Valid 271200Z - 281200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM EASTERN OREGON INTO SOUTHWEST IDAHO... CORRECTED FOR OUTLOOK GRAPHIC ...SUMMARY... Isolated strong thunderstorms capable of downburst winds and some hail may occur from parts of eastern Oregon into southwestern Idaho later Friday afternoon and evening. ...Synopsis... Upper pattern is forecast to be characterized by a synoptic upper trough over the eastern U.S., a ridge over the Intermountain West and a closed upper low moving into the Pacific Northwest region Friday. A significant shortwave trough located within the base of the eastern U.S. synoptic trough will advance through the Gulf Coast region. A cold front will move off the Atlantic Seaboard early in the period with trailing portion continuing through FL. Farther west a cold front will advance through the Pacific Northwest and Great Basin regions. ...Eastern Oregon through southwest Idaho and northern Nevada... Model consensus is that another in series of vorticity maxima will rotate through the closed upper low circulation and into northwest NV and central to eastern OR near peak heating. Steep lapse rates and deeply mixed boundary layers will support marginal instability with MLCAPE from 300-500 J/kg. The development of more numerous high-based convection should occur in response to the ascent accompanying the vorticity maximum being favorably timed with maximum afternoon and evening destabilization. Some of this activity could produce a few instances of downburst wind and hail through mid evening. ...Central through southern Florida... A gradual moistening will occur across south FL through Friday as the Gulf boundary layer modifies and surface winds return to southwesterly, though models have trended drier, suggesting more limited prospects for thunderstorms. Nevertheless, modest instability is expected in pre-frontal warm sector with MLCAPE below 1000 J/kg. Upper forcing will remain weak during the day promoting a shallow frontal circulation, but at least a few showers and isolated thunderstorms might occur especially along the east coast where frontal convergence will be augmented by the seabreeze circulation. An upstream shortwave trough will move through the Peninsula overnight, but the forcing with this feature will remain in post-frontal zone. ..Dial.. 04/26/2018 $$
![]() ![]() ![]() |
WxWebAPI: 4.02-4beta © 2018 MichiganWxSystem, LLC Powered by ![]() ![]() < ![]() WxWeb by MichiganWxSystem is licensed under a Creative Commons Attribution-ShareAlike 3.0 United States License. International Weather By:World Weather Online |
Support Wiki |
![]() ![]() ![]() ![]() |