Simulated Satellite for Evaluation of CI Timing

The Tuesday 5/22 EWP focus will be over the northern Plains in the Bismarck (BIS) and Grand Forks (FGF) forecast regions.  As of 20 Z storms had yet to form in the region, so the forecasters were looking at the simulated NSSL WRF imagery to get an idea of the timing of convective initiation.  The 4-panel image below shows the simulated IR and WV bands (top) along with the corresponding GOES-13 IR and WV bands (bottom), valid at 20 Z. Cirrus is abundant in the region in both the simulated imagery and from GOES, complicating the forecast.  But a qualitative comparison reveals that the model appears to have the cirrus in roughly the correct locations, and the shortwave trough and associated cold front in Montana seem to be placed properly at 20 Z.  (This is even more evident when viewing the imagery in a loop in AWIPS-II.)  This provides the forecasters with confidence in the subsequent NSSL WRF forecast imagery.

Below shows the simulated imagery valid 2 hours later, at 22 Z.  It shows that the first storm has formed over west-central North Dakota.  We will evaluate whether or not the model CI forecast was accurate a little later today.