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Sunday, January 28, 2018

Spring, winter, spring, winter... typical weather for this time of year!

After spending much of the first three weeks of the year in the deep freeze, the past week or so has been much more pleasant overall. Five of the past eight days saw average temperatures 10° or more above normal, while only one day was below average and that was just by a degree. Overall a nice recovery from a bitterly cold end to 2017 and start to 2018!

Average temperatures for the past 7 days were much above normal for everywhere east of the Rockies, especially when compared to the month-to-date average shown below! The pattern has done an about-face in the past week! (WxBell)

Today has been gorgeous - more like early March than late January! Sunshine and 60° is always welcome in the "dead" of winter. However, looking ahead things get rather tumultuous in the coming week or so, marked by a very progressive pattern that features a couple of fronts and areas of high pressure that pass by rather quickly, and roller coaster temperatures. Finally, as we get towards next weekend and the following week, a lobe of the famed "polar vortex" drops into eastern Canada and the northeast sector of the U.S. It will bring very cold air to that region, but a muted influence in the Mid-South, where a battleground may set up between the cold to the north and warmer air to the south.

Monday

A dry cold front that brings some measure of cloud cover to the region, moves quickly through during the early morning hours. This front, though dry, will bring an end to the warm weather we had today as highs don't quite reach the 50° mark. A north breeze will make it feel more like the 30s to near 40. Don't forget the coat you didn't need on Sunday when you head out in the morning!

The surface map as of 6am Monday shows the weakening front near the Mid-South as high pressure builds into the region from Canada. That high will mean much cooler temperatures to start the week. (NWS)

Tuesday

A cold day is in store as high pressure quickly moves through, resulting in less wind and sunny skies, but temperatures that start in the mid 20s and only reach the mid 40s. Wind becomes light under high pressure, then turns southerly Tuesday night as the high slips quickly off to the east.

By Tuesday evening, high pressure has moved through the region and is just to our east, setting up southerly flow and warmer temperatures for mid-week, as yet another system forms east of the Rockies. (NWS)

Wednesday

As low pressure develops in the Southern Plains and with the aforementioned high off to our east, steady south breezes and sunshine quickly warm temperatures back up from near 30 as you head to work or school well into the 50s by mid-afternoon. This will likely be the nicest day of the week if you don't count today!


Wednesday morning - total lunar eclipse!

Also of note on Wednesday, a total lunar eclipse will occur just before moonset and as the sun is about to rise. The image below provides the details, but the event will occur low on the western horizon, so if you have trees or buildings blocking your view of the horizon to the west, you likely won't see the total eclipse.

The penumbral eclipse will be very hard to notice, but the start of the partial eclipse will be visible to the naked eye (and no eye protection is needed for lunar eclipses!). The moon will be in totality for about 5 minutes before it slips below the horizon. Note that the altitude of the moon at 6:51am is just 1° - you won't see it if you don't have a clear view of the horizon! Sky conditions, however, currently appear to be excellent for viewing. It's also worth noting that this total eclipse is of a supermoon - when it's distance from earth is at its minimum - a "Total Eclipse of a Supermoon!"

Time sequence of events related to the total lunar eclipse on Wednesday morning. (timeanddate.com)

Thursday

The low over the Plains moves our way as another cold front slips through during the day. Temperatures will still be near average, perhaps falling by mid-afternoon, but rain chances increase dramatically as we go through the day. As cold air dives in after dark behind the departing system, rainfall starts to push east. Computer models have been hinting at some frozen precipitation on Thursday night for the past several days, but now seem to be narrowing the chances to just a few short hours before precipitation ends, when it may get cold enough for a bit of snow. I wouldn't hold my breath, as oftentimes the precipitation departs before the "cold-enough" air arrives. Stay tuned to our forecast! It could change as we get closer.



Friday

Earlier model runs had again hinted at lingering precipitation (likely snow) early on Friday. I find very little chance of that at this point and will go with diminishing clouds and below average temperatures - likely with highs in the 40s and a cold breeze. Again, we'll watch it carefully, but for now it looks dry and cold. Morning lows will be near freezing as the groundhog - or some other flavor of rodent, if you prefer - makes his appearance to tell us about the next 6 weeks.


Super Bowl Weekend & Beyond

Saturday currently looks dry and a bit warmer as we will probably be between systems again. An average early February day is the best bet. The crystal ball gets foggy after that thanks to a wide range in computer model opinions. As the polar vortex sets up shop well to our north, the pattern locally could get active with generally below normal temperatures and perhaps above normal precipitation. The first full week will be one to keep an eye on! I make no promises.

The map above shows the American GFS model ensemble of temperature anomalies at 850 mb (about 5000', and a good proxy for above/below normal temperatures at the surface) for the period February 2-7. What stands out is very cold air in Canada, seeping down into the northern U.S. In the Mid-South, we're on the edge of that "cold air bubble," indicating a likelihood that we could be in the "battleground" between the cold/warm air to our north/south, respectively. We'll have to watch for any precipitation events that might also be borderline. (WeatherModels.com)

Stay up to date with the latest local weather conditions, human-generated forecast, and precip-typed radar with the MWN mobile app! Not only do you get the best local weather information in the convenience of an app, you get to support your favorite independent weather source in the Mid-South at the same time! What a deal! You can find more info at the link below.

Erik Proseus
MWN Meteorologist

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