After a wild warmup, colder air returning on Saturday
Richmond didn’t just thaw out after the snowstorm; the thermometer soared from zero to 70 degrees in just 79 hours.
There isn’t an official record for Richmond’s fastest warmup, but that was certainly among the area’s biggest temperature rises in such a short time.
Thursday’s high of 70 fell a degree short of tying the daily record for Richmond. Jan. 12, 2005, brought a high of 71.
It should be no surprise that the pendulum is about to swing back to colder weather this weekend. Fortunately it won’t swing all the way to more record, bitter cold.
The magnitude of this week’s warmup was unusual, but it actually makes sense in the context of the larger weather pattern. A strong upper-level ridge or trough is usually required for a temperature extreme. When Virginia is colder than normal, the opposite extreme can often be found on the other side of the country. The west-to-east movement of our weather creates the familiar back-and-forth temperature swings. The pattern over the past several days was more amplified than usual.
On Sunday and Monday, the jet stream generally took a curvy path from the northern Rockies down to the Southeast U.S. and back up to the Canadian Maritimes. In other words, a deep upper trough was crossing right over Virginia.
By itself, the pattern probably wouldn’t have led to record lows; but the snow-covered ground helped push the temperature at or below zero around Richmond on Monday morning.
That big dip in the jet stream weakened and migrated out into the northern Atlantic Ocean. By Thursday, the jet stream flowed from southwest to northeast over the country, from California to the Great Lakes.
Virginia and the East Coast are now under the influence of an upper-level ridge that will persist into the weekend and next week.
Richmond will actually cool down over the weekend despite the presence of the ridge aloft. A northeast wind will force a shallow layer of chilly air into the region — the familiar “wedge.” It will be noticeably colder, but not dangerously cold.
Another taste of springlike warmth is a good possibility next week, but it won’t appear until surface winds blow in from the southwest on Tuesday and Wednesday.
Wintry mix may return soon
The intrusion of cold air on Saturday might be enough for light wintry precipitation in some parts of Virginia, but don’t expect a repeat of last Saturday’s snowstorm.
Cold air will slide beneath a layer of warmer air aloft, which could mean sleet pellets or freezing drizzle in Northern Virginia. The chance may get as far south as Richmond, but the lack of an organized system will keep any amounts on the very light side.
In Richmond, expect an overcast sky with a narrow range of temperatures in the mid-to-upper 30s throughout the day.
Even light amounts of freezing drizzle can cause messy roads. It’s a good idea to stay aware of conditions if traveling toward Washington D.C., Staunton or Harrisonburg on Saturday.