As the confidence slowly increases for this next April winter storm that will impact a fairly large area of the country, we have decided to release our first forecast of several for this storm. Understand that this is still a moderate confidence forecast, especially in the Northeast, based on the fact that the model guidance is not fully in agreement with each other.
Impacts from this storm will begin Thursday night as energy moves from the Northwest to the Central Plains, bringing a light to moderate snow from the northern Rocky Mountains through portions of the Great Plains, including South Dakota and Nebraska. By this point, we’re going to start to seeing pressures lowering east of the Rockies in the Southern Plains, which signifies an area of low pressure forming and strengthening. This low pressure will be the main instigator for this impending winter storm as it allows for a more-organized storm system.
On Friday, this storm will impact a large portion of the Central US. Snow is expected to fall from southeastern Wyoming and northeastern Colorado through much of Nebraska and Kansas and into much of Missouri, especially the southern half. Meanwhile in the Ohio Valley where snow is expected Friday night, there will be rain showers that impact the region in the afternoon. For the above locations that are expected to receive snow during the daylight hours of Friday, there won’t be much snowfall. We’re not talking about a widespread heavy batch of snow moving though. Instead it will be broken up areas of snow that will produce a coating to an inch to most locations. Temperatures on Thursday will be way above freezing, and they will become marginal, getting down to around freezing, when the snow falls. Therefore, most roads should be in good shape for travel.
Then overnight Friday, this will become an Ohio River Valley snow event. Snow is forecast to fall Friday night from portions of Missouri and through the Ohio Valley. The heaviest of snow will be centered near or just south of Ohio River, so heavier snow can be expected in Kentucky, especially the northern half, while lighter snow falls north of the river. A light snow may also extend into western and southern portions of Pennsylvania, West Virginia, northern Virginia, and Maryland. Because the snow is falling overnight, much of this snow will accumulate, especially where snowfall rates near or exceed 1 inch per hour. The best areas for that kind of snow will be in Kentucky as rain changes over to snow for the southern half of the state.
Now on Saturday, this is when the forecast confidence slightly drops. While snow clears out of the Ohio Valley by midday, where rain may even briefly changeover to snow in portions of Tennessee, portions of the Mid-Atlantic will be dealing with a moderate to heavy snow. This will be an all-snow event with snow expected through most or all of the day in northern Virginia, all of Maryland, the northern DelMarVa, southeastern Pennsylvania, and most of New Jersey. As you get up toward New York City, Long Island, and southern New England, these areas are currently forecast to be under the outer-extent of the precipitation shield so a light snow is possible at times, but given the low snowfall rates, little to no accumulation is expected. Now if the track of this storm where to shift more to the north, then a more substantial snow is possible while warmer air intrudes into the areas south of the Mason-Dixon Line.
Now for a city like Washington, DC, which has featured many complicated snow forecasts this winter, rain is expected to changeover to snow at around sunrise, and it could be a heavy snow at that. Once that changeover occurs, temperatures are likely to crash down to the low 30s. We’ll then see that rain/snow line try to work down to the southern border of Virginia as the day progresses, but this will mainly be a rain event south of Richmond. The best chance for the worst impacts in terms of road impacts, travel, and heavy snow will be in northern Virginia and into the higher elevations north and west of Washington, DC. These areas will be dealing with the coldest of air compared to the rest of the region. Potentially significant impacts are also possible in the I-95 corridor, especially between Washington, DC and Philadelphia. Again, if a light snow falls, roads will be fine and there will not be much accumulation given the strong April sun. But if it’s a heavy snow, then that snow will accumulate everywhere, as we learned with the storm that hit parts of the Northeast earlier this week Sunday night into Monday.
By Saturday evening and Saturday night, there will be some lingering rain and snow showers for the Mid-Atlantic but the main impacts will be done as the low pressure moves offshore. This will be weak wave of low pressure instead of being a rapidly-developing nor’easter that moves up the East Coast. This storm is currently expected to take more of an out-to-sea approach, but with most of the storms, a last-minute adjustment to the north and west would not surprise us, thus bringing snow to parts of the New England coast Saturday night into Sunday. Therefore, the chance for snow is definitely not zero, especially in southeastern Massachusetts.
Now let’s talk snowfall accumulations. Accumulation will be light in the Plains while heavier snow becomes present once you get into the Ohio Valley and Mid-Atlantic. Confidence is higher on where the heavy snow will fall in the Ohio Valley compared to the Northeast. A heavy band of snow is expected to develop, but where it orients itself is still the question.
Continue to monitor the forecast from WeatherOptics for daily updates on this storm.