Jan 29, 2011: Wednesday Storm Discussion

Today was a mostly cloudy day for the area, with another clipper producing light snow for the area with accumulations less than 1/2 inch. Conditions will dry up starting tomorrow, with tomorrow being the first day since Monday the 24th that the area has not seen snow. Another storm is expected to affect the area by the middle of the week, however this time, rain and ice are a bigger concern than snow.


Sunday And Monday: Cold Again

Tomorrow will be slightly warmer than yesterday, with high temperatures expected to be in the mid 30s inland and in the mid to upper 30s for the rest of the area. Tomorrow night, however, is expected to be very cold, with low temperatures back into the single digits inland and the 10s for the rest of the area including NYC. Monday will bring colder high temperatures, expected to be in the mid 20s inland and in the mid to upper 20s for the rest of the area.


Mid Week Storm: Some Snow Tuesday, Then Mix/Rain

While yesterday, the model guidance suggested a storm that may bring mostly snow with some mixing with sleet for the area, today's models have trended warmer and further north, most notably the GFS, and now bring some snow to ice, then heavy rain for the area. Below, I will discuss in more details what factors I used in today's forecast and how it may change.

It appears that the storm will come in two parts. The first part will be an overrunning event on Tuesday, where an area of moderate snow is expected somewhere near or north of the area. For this part of the storm, I used the NAM, which has been the most consistent in showing this event clearly, while the GFS only has been trending a little wetter with some light precipitation. It appears that the area will see snow to start on Tuesday with light to potentially moderate snow accumulations possible, with perhaps a few inches at most, followed by a changeover to mixed precipitation by the evening or overnight as 850 mb temperatures warm above 0c but surface temperatures remain below freezing.

For the second part of the storm, I used a solution close to the 12z/18z GFS. This will be the main storm and will be during the day on Wednesday, though the models have been trending wetter, warmer and further north. The GGEM is currently the southernmost solution with snow/mix for the area, though it appears to be too far south and with that model still being inconsistent, I did not use the GGEM for my forecast tonight. It appears that we may see a mix changing over to rain, potentially heavy at times.