Updated by: Andrew Freiden and Matt Holiner 3/4/15, 6:45am
There is yet another winter storm that is targeting our region beginning late tonight through the day tomorrow. In terms of forecasting, this particular storm is much more challenging than the last storm.
Why is that the case? Well first, the biggest problem lies in the fact that temperatures are expected to be in the 60s today in advance of an approaching cold front. Second, we're going to see a SOAKING RAIN before the cold air returns so the ground will be warmer and very wet. Third, the timing of the cold air will be crucial to when there is a changeover from rain to sleet and then snow, which will have a major impact on total snow accumulations. Computer guidance is NOT in total agreement on the timing of that cold air and the subsequent changeover.
Our best estimate right now is for rain during the early morning hours tomorrow, with sleet beginning by late morning and continuing through the early afternoon. By mid-afternoon, sleet will transition to snow. Snow will continue through the early evening hours. The wrench that could get thrown into this forecast is the duration of the period of sleet. If the rain to snow transition happens quickly, we'll get a bigger snow total than the map below shows.
All these factors being considered, here is a look at expected snow totals over the region. Keep in mind that there will likely be a tight gradient of totals from north to south....highest totals north where the cold air changes the rain from sleet to snow more quickly. Lighter totals to the south where more sleet is expected and less snow. Regardless of snow and sleet totals, travel will become more difficult as the day goes on tomorrow. With temperatures expected to fall into the upper 20s by mid-afternoon, the evening commute could be particularly hazardous. Temperatures will continue to fall during the night, with lows Friday morning expected to be in the low teens.
As we see how this system develops tonight and tomorrow morning, don't be surprised to see adjustments to this map over the next 24 hours. Please stay tuned for updates!