Jeremy Perez
Supporter
With all the frustrations of a flimsy severe weather pattern setting in for the latter half of May, it still looks like there will be isolated/conditional opportunities in the northern plains and elsewhere as a trough moves onshore this weekend and starts the sad process of cutting off in the southwest early in the week.
For Sunday afternoon/evening, per guidance from NAM, I'm looking at a target in northeastern Wyoming as 40-50 kts of southwest H5 flow moves in over an area of low to mid 50 dew points advecting around a consolidating surface low in that target area. A narrow, meridional zone of 1500-2000 j/kg CAPE may develop along the eastern Wyoming border with the CAP weak or open by mid to late afternoon in the northern portion of this ribbon. If that confirmed, today's 12Z NAM forecasts a focal point for convection in this area by 00Z with that area potentially ingesting 100-150 m2/s2 0-1km SRH. Mixed layer LCLs are in the 1500 meter range and heighten quickly the further south you go.
If this plays out well, I might hope to see an isolated, high-based supercell drifting slowly into South Dakota. I have no expectations of anything tornadic with the setup. And if today's 06Z GFS has its way, then I can expect a bust with maybe some elevated showers in South Dakota (it keeps surface moisture about a hundred miles further east under stronger capping). 00Z ECMWF agrees better with NAM on placement of moisture and location of precipitation, so I hope that agreement favors my focus on NAM.
This will be my first 2014 chase day during a week of very iffy conditions. I'm definitely concerned that I'm setting myself up for a series of busts, but also excited to take on the challenge.
For Sunday afternoon/evening, per guidance from NAM, I'm looking at a target in northeastern Wyoming as 40-50 kts of southwest H5 flow moves in over an area of low to mid 50 dew points advecting around a consolidating surface low in that target area. A narrow, meridional zone of 1500-2000 j/kg CAPE may develop along the eastern Wyoming border with the CAP weak or open by mid to late afternoon in the northern portion of this ribbon. If that confirmed, today's 12Z NAM forecasts a focal point for convection in this area by 00Z with that area potentially ingesting 100-150 m2/s2 0-1km SRH. Mixed layer LCLs are in the 1500 meter range and heighten quickly the further south you go.
If this plays out well, I might hope to see an isolated, high-based supercell drifting slowly into South Dakota. I have no expectations of anything tornadic with the setup. And if today's 06Z GFS has its way, then I can expect a bust with maybe some elevated showers in South Dakota (it keeps surface moisture about a hundred miles further east under stronger capping). 00Z ECMWF agrees better with NAM on placement of moisture and location of precipitation, so I hope that agreement favors my focus on NAM.
This will be my first 2014 chase day during a week of very iffy conditions. I'm definitely concerned that I'm setting myself up for a series of busts, but also excited to take on the challenge.
