Winter storm brewing???November 29th, 2009 at 11:00 pm by Erik Zarnitz under News, Weather
This is the time of year when winter storms seem to show up every week on some of the extended model runs that we use. However it seems that for every three storms that pop up only one verifies. This is our latest interest.
Here is one slide from the Sunday 18z run… painting a new storm across the east. This storm system originates across the Gulf Coast (typical with the stronger southern branch of the jet do to the influence of El Nino) and moves up the back bone of the Appalachian Mountains.
This scenario is one of the most common ways for the Miami Valley to see a “big snow” event. This early in the season it can happen but we need many things to come together… and perfectly. First the track has to remain virtually identical to this model run, and for anyone who follows weather, a model typically has the idea of storm correct but the placement is normally off. Second, when forecasting the 540 line is a general guide for all snow. That line splits the Miami Valley right down the middle. On top of that southern systems (since they move up from the south) bring warm air up with them, sometimes making a change over to rain take longer then possible. If EVERYTHING came together perfectly we
could see significant snows here in the Miami Valley. While that is a possibility, it is slim. Right now probably around ten percent or so. A much more likely scenario is rain, then as the storm system pulls away a few light snow showers with windy and cold conditions.
This map to the left may look a little complicated but it’s an overlay of the GFS and the ECMWF (a more reliable long term model in this forecasters mind). With this consensus- windy, cold, with light snow is almost a given. The only question is whether or not everything will come together to make this more of a snow, then a wind and cold event.