The problems are temperature and timing,
not the amount of snow.
POSTED 4:30 AM FRI 2/1/19
- CONTRARY to what we posted Thursday about today's snowfall potential, a closer examination indicates that road conditions in areas between I-66 and I-70 to the PA line are likely to become significantly icy this morning in a short period of time once snow begins. This is underscored by a Winter Weather Advisory for much of the region from 6 AM to 3 PM today.
- TEMPS: With road and air temperatures in the teens in many locations north of I-70, per MD state road data, most bulk road salt applications have sharply reduced effectiveness. This means any snow reaching the surfaces will freeze on contact, because the salt is not able to raise road temps sufficiently to induce melting or create a sheen of chemical/water mix that vehicle traffic helps spread around over time.
- TIMING: Even light snow arriving 6-7 AM is going to produce uneven patches of ice on roadways, because residual salt on roads may not evenly distributed. Thus in a light intensity event coming right at start of AM commute, with tiny flakes freezing on surfaces, it will not be known what areas are icy or not until your wheels or feet encounter them. Despite it taking 4 hours to reach 1" of snow, the impact to roads will develop immediately due to the early AM timing and the low temperatures.
- NWS HOURLY SAMPLE: With most areas in central & northern MD at similar temperatures and expecting light snow 6 AM to 2 PM, here is Owings Mills in Baltimore County as representative of the region:
