For the first and likely only time this week, we have Slight Risk areas in the Day1 Outlook from the SPC.  We will use our time this afternoon to prep the HWT systems for a MRMS IOP to take place in Wyoming/Nebraska.  The Florida Slight Risk is also intriguing, with several slow moving storms acting at times like supercells.  Lapse rates are not very steep, so the main hazard is tornadoes.  This event was ongoing early in the afternoon, however, and the risk area on the central High Plains syncs better with our operations and the availability of technical support in the HWT.

Surface analysis revealed low pressure along a cold front in the eastern Dakotas.  A pre-frontal trough extended through central Nebraska.  Our focus for convection, though, will be the front and a deeply mixed boundary layer just south of the front in southeast Wyoming.

Models are consistent with a QPF signal developing in southeast Wyoming…and progressing along the stalled or slowly moving cold front in northern Nebraska and far southern South Dakota late this afternoon and this evening.

This looks to be our best opportunity for a real-time IOP this week.  VORTEX2 will also be operating in our target area.

Patrick Burke (EWP Weekly Coordinator, 18-22 May 2009)