Sunday, March 1, 2015

March comes in like a lion, or maybe a snow leopard

Welcome to the first day of meteorological spring! We in the weather business compile seasonal weather and climate stats according to "meteorological seasons." March-May is considered "spring." Unfortunately, the first week of March looks more like a continuation of winter (with a one day exception) than spring.

Fe"brrrr"-ary recap

First, a brief recap of the month since the groundhog poked his head out of the burrow. February seemed to be when winter STARTED this year, particularly the last 2 weeks. The tables below showed that the month was preliminarily the coldest since 1978 and the 7th coldest since 1875 in Memphis. That was driven mainly by the last two weeks of the month (when normal highs are in the upper half of the 50s), which was the coldest last half of February on record, and it wasn't even close, shattering the previous coldest by nearly 5.5°F!



So I know we all want winter to end after the last two weeks. Unfortunately, except Tuesday, the first week of March looks to continue the recent cold. The month will be coming in like a lion (or maybe a snow leopard) this year!


Early this week

An inclement few days is ahead as a frontal system wavers through the area to start the week. Showers will occur today as a cold front draws near. That front moves through tonight with rain expected. Fortunately, temperatures  should stay just above freezing tonight so no icing is expected in the metro, but wind chills will be in the 20s Monday morning. A few showers will also occur Monday with a north wind  holding temperatures in the mid 40s (normal is near 60).

As low pressure develops in the central U.S., the front will pull back north overnight Monday night with temperatures rising and more showers expected. By Tuesday morning, we'll be above 50 with a south wind kicking up. Tuesday, although wet, will be the warmest day of the week with highs well into the 60s. Thunderstorms will be likely though Tuesday night as yet another cold front (this one with Arctic air behind it) moves through the region. (At this point, they do not look severe.) The Arctic reinforcement arrives Wednesday morning.

The NWS indicates a cold front moves through the region Tuesday night, followed by a reinforcing Arctic front Wednesday morning as shown above.

Wednesday - too early to call for sure

Wednesday's high will occur at midnight and temps are expected to fall all day. We should see the mercury in the 40s Wednesday morning as we wake up, but look for temps to fall to freezing sometime during the day Wednesday, with precipitation continuing.


(Yeah I've used that animated GIF in the past couple weeks already, but is there a more appropriate one?)

So this is where it gets tricky! It's too far out to know exactly when that happens, how fast the low to mid levels cool down (which is critical in precipitation type forecasting), as well as how much precipitation falls into cold air and when it ends. There are model opinions that literally run the gamut, from cold rain to Snowmaggedon (hey, why hide the truth). But these models literally change multiple times a day, and your national weather apps that run on them do too. We will not forecast ice and snow amounts and timing at this time - it's simply too early to know with any certainty! Whatever we would say, we'd be lying.

What we should ALL prepare for, though, is the possibility, perhaps even the likelihood, that another round of winter weather will affect the entire region Wednesday, maybe into Wednesday night. Snow and/or sleet/ice accumulation COULD be significant, but we won't make a call on that yet. In this situation, it's a must to follow trusted sources for weather info and prepare accordingly. Check them regularly. A forecast from Sunday or Monday will most certainly not be right come Wednesday, but trends are important.

End of the week

Looking beyond Wednesday, Arctic air pushs in once again for a few days with lows probably back in the teens and highs in the 30s to end the week. Hopefully this is Old Man Winter's LAST GASP! I know you're over it... so are we!

We'll be keeping a very close eye on it, and when we feel comfortable doing so (maybe late tomorrow) will make a first call on what to expect. Follow us on Facebook or Twitter for the latest info and you can always check our latest forecast on MemphisWeather.net, our mobile apps, or mobile website.

Erik Proseus
MWN Meteorologist

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