Thursday, January 12, 2017

20s to 70s - it's winter in Memphis!

For those of you who were tired of the 88 hours of sub-freezing temperatures we had late last week and into the weekend, you got your wish. We're back in the 70s! Welcome to the bipolar weather of Memphis, where lingering snow one day is completely melted by 60s and 70s the next day!

Arrival of a cold front

A general warm pattern looks to continue well into next week, but we do get a reprieve of closer-to-average conditions tomorrow, as a cold front moves across the metro this evening, lingers just to our south into Saturday, then makes a return trip back to our north as a warm front this weekend. If you're out and about this evening, you'll likely notice the front between 8-10pm as warm and humid conditions give way to showers and then a shift in the wind to the north, accompanied by a roughly 20-degree temperature drop. Here's forecast radar for this evening and overnight showing the rain:

Forecast radar for the evening and overnight hours from the HRRR model. If the GIF doesn't animate, click here. (WxBell)

Friday into the weekend

With the front stalling just to our south, the much cooler surface air combined with a strong temperature inversion (warming air with increased height, rather than typical cooling) and abundant low-level moisture that produces a low cloud deck, will result in much cooler temperatures tomorrow. Look for morning bus-stop temperatures in the mid 40s and highs not much warmer, in the lower 50s. A cool northeast breeze will provide a stark contrast to today's tropical breezes and mid 70s highs!

A vertical cross-section of the atmosphere at 6am Friday, according to the NAM model, clearly shows the inversion and low-level moisture that develops behind tonight's cold front. The inversion will serve to trap low clouds in place until sometime Saturday, resulting in much cooler and overcast conditions.
The inversion and cloud cover remain in place Friday night and into Saturday, keeping temperatures nearly steady Friday night near 50° and introducing the possibility of areas of dense fog. By Saturday afternoon, some sun may break out as the front starts to return back to the north. allowing the mercury to climb back to 60° or higher. Sunday promises to be a day not unlike the last couple with highs once again pushing the 70° mark and some afternoon sun expected between the clouds. With the exception of a stray shower, or drizzle Saturday morning, most of the weekend looks to be dry.

Next week

Looking at next week, a large scale system to our west, that is held at bay through the weekend by the Bermuda High pressure system over the southeast U.S., will start slowly moving east. A few showers are possible Monday, mainly afternoon and evening, as highs reach near 70° again. By Tuesday and probably into early Wednesday, periods of heavy rain and some thunderstorms are possible as the system, and it's upper level low, cross the region. Temperatures will remain mild, so there are no winter weather concerns, but not as warm as Sunday and Monday. We'll be watching rainfall amounts closely as some flooding is possible if heavy rain is prolonged.

The NWS predicts a solid 2" of rain for the metro over the next week with heavier amounts to our west where some impactful icing is also possible this weekend. (WPC/NOAA)
For those looking for more "winter-like" conditions, there are some long-range signs of a pattern shift late in the month. Cross your fingers! You can always check for details out a week in advance in the MWN mobile app or on our website. Look for the human-powered MWN Forecast!


Erik Proseus
MWN Meteorologist

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