Short Range Web Technical

With one clipper moving out or our region and deepening quickly as it heads off to the Mid-Atlantic region, we have another weak disturbance that will be moving down the Northern Plains in its place. Currently over the Pacific Shore of British Columbia, Canada, This system is expected to propagate towards our direction. As it does so, an overall weakening trend will be taking place. Temperature advection will be decreasing with the system with surface pressure around 996 today looks to be around 1011mb by the time its centered over Central Iowa at 00Z Sunday. Weak precipitation in the form of snow will be crossing across the IL IN border around that time-frame. Omega will be weakening as well supporting the weakening trend as it approaches our area. The vort max looks to mass over us around 06z Sunday with 850 winds paralleling the Isobars. The NAM is a little bit more aggressive with this system vs the GFS and so far this winter season seems to be doing better in regards to handling the winter events, but looking at the forcing and other models such as GEM and ECMWF, going to lean towards the mid-range runs and disregard the NAM for now, believing that it is overdoing the energy associated with the system.

After this system, our attention quickly turns to Monday As a surface low looks to develops quickly over Central IL and could track right over our area. A southerly trend on the runs has been noticed and with what was once expected to be a complete rain system looks to be leaning more towards a freezing rain and rain system. GFS seems to be having a harder time developing the surface low while GEM, ECMWF, and NAM are in much better agreement. The good news is that after this system pushes through, we will be going into a zonal and even into a slight southwesterly stream by Thursday, Long Range will be taking it over from there. Reason I bring this up is that for any mix or freezing rain accumulation that could accumulate, it will quickly melt as temps will be pushing into the upper 30's and 40's.

RECCHIA