Why weather is so tricky for Washington DC

 well  weather i s tricky for the mid atlantic area because there are so many factors and as we meteorologists say sometimes when it comes to winter storms their is a high bust potental thats why in most cases the National Weather Service in sterling VA has been so lazy to issue winter storm watches and or warnings for snow storms and ice storms because things could change here in the mid atlantic area  the  Atmospheric dynamic  and there is a varying span of elevations between the bay and shore and the mountains  anywhere from Sea Level to 4000 ft in the mountains so  Washington proper and points at lower elevations  could see rain and some mixing in times of winter storms and points north and west of The city could see cold air and more wintery precipitation a good example of this was around the time of the vernal equinox last year  we got 4.5 inches of heavy wet snow and Washington DC had spring rain storm that was purely driven by elevations above sea level and anywhere north and west of the cities of washington dc and baltimore  got rain
We also have the I-95 Fall line  where the warm air advances to and the cold air north and west of there damns agenst the mountains. the "FALL LINE" just means thats where the Rain/Snow  battle line sets up and doesnt advance any farther than that north and west  that keeps all the northern suburbs for montgomery county north and west  in the colder air and more snow or sleet or feezing rain.  while points south and east around the tidal potomac and  Pax River NAS get all rain or a mix of rain and sleet  Montgomery county gets snow and or sleet and snow mixed or snow sleet and freezing rain  but sometimes it gets a cold rain too but thats if the rain snow line pushes farther west and north than the I-95 line .

New Model

I have been working on a new Model a model that combines the best of Geographical information Systems (GIS) and the GFS and the  other models for forecasting for the Washington Dc metro area  it has the topographic maps of the US Geological  Survey  and  the best of the models used in weather Forecasting the Canadian and the ECMWF and the GFS and the NAM the best of all of those models its called the

   Geographical Weather Forecast System or GWFS its been designed to take in to account the Geographical differnces between Washington Dc and  places like Rockville Maryland  Rockville is higher in elevation that Washington DC is and  so is the eastern shore and lower central maryland it takes that into acct and can forecast winter storms with fairly acurate relyablity  maybe 85 to 95% of the time it can but it sometimes goes back to its GFS Roots and underperforms but thats because its a GFS based model blend of all  the other models out there and the  GFS.

anyway the model was  developed by  me it took a year to develop and it took another year of in operational testing to make shure it was ready to go to National weather service offices through out the country and hopefully it will help improve Forecasting in all the areas its in operation  2014 is the first year its in full operation and so far its had a decent sucess rate with winter storms  from time to time it goes back to its GFS roots but thats ok no numerical model is perfect  so yeah the rest is complicated technical stuff.