Sunday, January 29, 2012

Forecast for Monday, January 30, 2012

Tonight, a strong cold front will pass through the area. Both the NAM and GFS have come in drier with latest runs. However, there still appears to be a chance for snow squalls or a round of snow showers. As I mentioned yesterday, the best chances of this happening are north and west of the city. There still appears that raindrops could mix in initially in any snow shower closer to the coast, if it precipitates at all in these areas. Winds will increase and gust between 35 and 45 MPH. Any snow shower may combine with the wind to cause reductions in visibility. At this point, it is a touch of snow at best for most with scattered coatings. It is possible that in the Poconos there could be a narrow area of highly localized inch reports. With dropping temperatures, it may cause spots of black ice.

Our next issue will be a weak warm front on late Monday Night into early on Tuesday. The moisture with this system is not too deep. Therefore, I think there may be a few areas of patchy drizzle and fog. If temperatures fall back a bit in the evening, north and west may have some spotty freezing drizzle. If moisture with the front happens to be great enough…some light snow cannot be ruled out.

Tuesday still looks like a day where if a temperature forecast were to go wrong, this is when it would happen. The warm front will hopefully progress far enough north to allow Philadelphia to at least hit the mid-fifties. On Wednesday, ahead of a cold front, temperatures may hit or do better than sixty degrees. A line of showers with perhaps a rumble or two of thunder and gusty winds may develop ahead of the front. There remains considerable uncertainty about how far east this front moves before putting on the breaks. This is important as some of the model guidance is suggesting a wave of energy developing along the front Thursday into Friday. Another system may also impact the area for the weekend. It is too early to get into precipitation types at this moment with such high uncertainty. Temperatures for now are a middle ground and may be swung up or down in future forecasts. Models have performed very poorly this winter in the long range.