Outlook 22 May 2012: Week 3, Day2

Focus for operations is over the Dakotas for today.  Initially, forecast teams were separated into the Bismark and Grand Forks CWA’s, but with delay of any CI, we quickly decided to re-localize the FGF team to Aberdeen, SD.

The HRRR remains quite aggressive at initiating convection across both ND & SD as well as Montana by 2030-2100 UTC, though lessening in strength and coverage with each run (earlier runs developed a strong line of storms and it has moved to smaller, more isolated, cells in recent runs). Almost all the high-res models had similar solutions thought, and initially working off of the NSSL-WRF from last night convection was first expected by 2100 UTC.

The low pressure in ND with corresponding warm front extending across the ND / Canada border still holds promise.  Steep lapse rates, combined with low-level curvature in the hodograph point to supercells with large hail (and isolated tornadoes) if and when storms finally develop…

In the meantime, thick cirrus coverage is preventing the UW-CIMSS Cloud-top-cooling and UAH-Convective Initiation algorithms from flagging any development across the majority of ND.  But the CTC does seem to be flagging development in Montana…

Cloud-top-cooling ove Montana at 2025 UTC.
SPC day 1 outlook for 22 May 2012. 2-5% tor, 15-30% wind, 15-30% hail (hatched) for the ND/SD region under the slight risk.

-K. Calhoun, Week 3 Coordinator

Tags: None