A surprise wintry mix caught many off guard on Sunday and caused school delays on Monday morning. But that was just a preview of what lies ahead in the coming week, as two major winter storms are expected to bring the risk of icy conditions. Road salt will be in high demand, as shovels and plows may not be sufficient for the task at hand.
The winter storm that we will be focusing on in this article is expected to occur from late Wednesday through midday Thursday. There are projections from some short-range models indicating the possibility of a thin band of moderate snow extending from the north Pittsburgh suburbs to the Lower Susquehanna Valley on Wednesday afternoon. We will be closely monitoring this development. However, the main event is expected to start shortly after.
In this weather scenario, a high-pressure system positioned to the northeast will trap cold air in the Appalachians, resulting in a phenomenon known as cold air damming. The most severe effects will be felt in the mountainous regions. Initially, precipitation will begin as sleet, then transition into freezing rain, before finally changing to plain rain.
Thursday’s weather forecast may suggest temperatures in the 40s or 50s, but this is only likely to occur in Southwest PA. It is important to note that during cold air damming events, temperatures often remain lower than what the models predict. However, we can expect the ice to thaw out as temperatures reach the mid to upper 30s on Thursday afternoon.
WINTER STORM TIMING CHARTS
This Article Includes
The timing of this event will vary depending on local conditions, including temperatures in the upper levels of the atmosphere and at the surface. Factors such as topography and microclimates will have a greater influence than usual. The following timing charts take these factors into account. If you don’t see your specific town listed, please refer to the nearest city or area.
THURSDAY SNOW & SLEET FORECAST
During our initial call, we did not consider the possibility of a narrow band of snow in the areas we discussed on Wednesday afternoon. This localized feature will be included in the forecast for Tuesday, as there is still some uncertainty surrounding it.
In Area A, we can expect snow and sleet accumulation ranging from 1 to 3 inches.
In Area B, the snow and sleet accumulation will be less than 1 inch. This will primarily consist of sleet, which are ice pellets that can be difficult to shovel due to their weight.
FIRST CALL ICE FORECAST FOR THURSDAY
Please be aware that during icy conditions, all surfaces, including roads and walkways, can become slippery. It is important to exercise caution when walking to avoid any potential hazards caused by the presence of ice.
Area A is forecasted to experience significant ice accumulation, with ice expected to accumulate between a quarter and a third of an inch (1/4 – 1/3″). The roads in this area will become extremely slippery, posing a hazard to vehicles regardless of their tires. As a result, schools are expected to be closed on Thursday, and businesses in this area are likely to close during the first half of the day.
Moderate to significant ice accumulation is expected in Area B, with ice buildup ranging from a tenth to a quarter of an inch (1/10 – 1/4″). This will result in extremely slippery road conditions, which may lead to school closures on Thursday and delayed business openings.
Area C is expected to experience light to moderate ice accumulation, resulting in a buildup of ice between a twentieth and a tenth of an inch (1/20 – 1/10″). Although it may not seem significant, this level of ice can greatly impact road conditions, making them slippery and potentially causing delays or closures for schools and businesses.
In Area D, we can expect a light ice buildup, with approximately 1/100 to 1/20 inch of ice accumulation. Although this may not seem like much, it can still create slippery conditions on surfaces. It’s important to note that Eastern PA might experience slower temperature warming compared to areas near Pittsburgh, making the surfaces even more treacherous.
