Full forecast: Light snow to intensify quickly Wednesday afternoon – WFMZ Allentown

SHORT TERM FORECAST

TODAY: Mostly cloudy and becoming blustery with snow developing during the afternoon. High: 31 

TONIGHT: Windy with snow, some heavy, mixing with sleet and rain south and east of the Lehigh Valley. Low: 25 

THURSDAY: Lingering snow and flurries in the morning, then clouds breaking for a little afternoon sun; brisk and cold. High: 33 Low: 16  

FORECAST SUMMARY

Tuesday was the calm before the storm, the storm being a significant early season winter storm still slated to bring snow and wind to the area later today into early Thursday, and for some, a mix of sleet and rain as well.

Accumulations are likely, and for most north and west of Interstate 95, expect a plowable snow with moderate to major accumulations, more so the farther north and west and higher up in elevation you travel. Things remain quiet through the first part of today, before snow develops and steadily intensifies through the afternoon and evening hours.

Winter storm timeline: Here’s what to expect Wednesday into Thursday

Overnight, expect some warmer air to change the snow to sleet from the Lehigh Valley south and east, and even plain rain towards parts of the Delaware Valley. Any nighttime mix may end as snow as the storm wraps up early Thursday morning, then cold and brisk but drier weather will be the rule the rest of the week through the start of the weekend.

DETAILED FORECAST

TODAY AND TONIGHT

Wednesday started dry as clouds thicken, with snow developing from southwest to northeast around midday and early afternoon. Snow starts light at first, but will quickly become steadier and heavy at times this evening into the first part of the night.

The cold ground and cold temperatures will cause the snow to stick right away, as opposed to the minor snow we saw earlier in the week. Between that and the heavier snowfall rates, road conditions will start to go downhill rather quickly during the afternoon and early evening.

Major Winter Storm timing graphic 12-16-20

North of Interstate 78 in the higher elevations of the Poconos, northwestern New Jersey, and along the Interstate 81 corridor through Schuylkill and Luzerne counties, the storm remains mostly snow. Along and south of Interstate 78 from the Lehigh Valley south and east, snow will mix with and change to sleet overnight, and even plain rain towards the Interstate 95 corridor and the Delaware Valley.

Accumulations

The mixing, plus a “dry slot” or lighter and more scattered area of precipitation, will cut into accumulations.

– Expect a foot or more of snow from the Blue Ridge and Slate Belt on north where things stay all snow.

– For the Lehigh Valley and along I-78 due to the added mixing issues, accumulations now look to be in the 8 to 12 inch range.

– Farther south and east where mixing is more prevalent, closer to but north and west of Interstate 95, 4 to 8 inches of snow are forecast.

– And south and east of the I-95 corridor to the shore, it’s mostly rain and wind with little accumulation of snow expected.

Gusty winds are expected to develop, especially tonight, when winds may gust to 40 miles-per-hour, leading to some blowing and drifting snow and some scattered power outages.

THURSDAY

Any mix Wednesday night can change back to snow or snow showers before sunrise Thursday before ending as the morning progresses, as our coastal storm quickly departs. A brisk northerly breeze will linger as will plenty of clouds, with some breaks developing later in the day.

Temperatures won’t move much, hovering in the low 30s most of the day as the cleanup and dig out begins. Add in the wind and wind chills remain below freezing throughout the day.

FRIDAY, SATURDAY, AND SUNDAY

High pressure builds in, the winds diminish, and seasonably cold air settles in through the start of the weekend. Don’t expect the snow to melt that quickly, with afternoon highs in the low to mid 30s and overnight lows deep down into the teens thanks to clear skies and a deep snow cover.

On Sunday, a weak cold front will be approaching from our west increasing the clouds. We will get a touch warmer ahead of the front as highs get back into the upper 30s to near 40 degrees…more seasonable for this time of year. The front may bring a rain or snow shower late in the day or at night, but at this time we don’t expect this to be a big deal.

 

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