Saturday, November 20, 2021

Thanksgiving Week forecast: one wet day - guess which one?

I hope you took advantage of a couple of days in the 70s earlier this week, because the atmospheric patter has definitely shifted back to providing a mid-fall feel. In addition to cooler temperatures overall, regular frontal passages will mean a swings in temperatures typically associated with fall - mid 60s one day and upper 40s a couple days later and morning lows that vary from sub-freezing to mild. 




This weekend

Today brings us weather more on the "mild" side as southerly flow pushes the mercury up into the low 60s. However, the next front is just around the corner and will bring our next round of rain on Sunday. Low chances start the day, but by lunchtime, rain is likely to be "likely" and will linger into the afternoon hours. 

The Saturday morning run of the HRRR forecast radar product provides this clue on timing for Sunday's rainfall. Loop starts at 4am and ends at 10pm. (WeatherBell)

Thunder is not expected, so the severe threat is also nil. Rain tapers off by late afternoon, leaving behind 0.25-0.50" of accumulation. The blanket of clouds arriving with the system will keep lows mild overnight tonight (near 50) but also hold them in check on Sunday, remaining in the 50s all day.

Total rainfall from Sunday's front will likely be between 0.25-0.50" for most of us, as shown by the NWS official NDFD forecast. (WeatherBell)


Early Thanksgiving week - sunny and cold

As skies clear quickly Sunday night, we will see temperatures fall into the upper 30s but with a breezy north wind, it'll be quite chilly Monday morning as you get up to start a (hopefully) short week! A few clouds will move in by Monday, but overall the sunshine will be offset by cold air pouring in behind the departing Sunday system on north wind, holding high temperatures below 50 degrees for highs. Keep the coat on as some of the coldest air of the fall settles into the region!

The upper air pattern at about 18,000 feet on Monday (as forecast by the European model) depicts a large ridge of high pressure in the western U.S. and a large trough of low pressure in the east. Colors represent departures from "normal" pressure values. The blues are indicative of cooler than average temperatures. (WeatheBell)


Tuesday morning will be the coldest of the week with lows in the 20s outside the city and near 30 where concrete acreage outstrips dormant grass. The airport still has not reached the freezing mark yet even though surrounding areas have; this might be the day the growing season officially ends. (We're now over a week behind the "typical" first freeze in Memphis.) Look for sunny skies for the rest of the day with a bit of afternoon warming as high reach the mid 50s. 



Wednesday is a transition from the cold dome early in the week to the next approaching front. High clouds are likely but temperatures will be milder as wind shifts southerly. Lows will be near 40 and highs near 60. Not bad for last minute trips to the grocery!

Thanksgiving Day weather - wet

Unfortunately, as the blog title suggests, there will be one wet day this week, and it appears to be on the holiday itself! Weather models have been having a bit of a challenging time determining the evolution of the mid-week system, but seem to be getting their act together. 

The Saturday morning GFS model (which is fairly well aligned with the European model) for Wednesday afternoon through Friday evening, shows a round of rainfall moving through on Thursday. Rainfall should be be excessive and thunder is low probability as well. Friday currently looks dry. (WeatherBell)


The good news is the rain likely won't linger more than a day, as previously thought, nor will it be quite cold enough for wintry shenanigans. The bad news is, if your house is full, the back patio won't be a great option with a chilly rain falling. Temperatures will generally be in the lower half of the 50s. 

We'll provide more detail on our social media feeds as the day approaches, perhaps with some dry hours to start or end the day, but for now that level of detail is about as fuzzy as leftover turkey in early December. Provided Thursday's rain moves out in good order, Christmas shopping season kicks off with seasonal conditions and dry skies Friday and Saturday.

Erik Proseus
MWN Meteorologist

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Follow MWN on Facebook and Twitter for routine updates and the latest info!
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MWN is a NOAA Weather Ready Nation Ambassador Meteorologist Erik Proseus is an NWA Digital Seal Holder

Wednesday, November 17, 2021

Magnitude 4.0 earthquake felt in Memphis metro

While the New Madrid seismic zone is known to produce literally hundreds of micro-quakes each year, it is rare that any are felt noticeably throughout the Memphis metro. However, on Wednesday night at 8:53pm, the New Madrid fault produced what we believe to be the strongest earthquake in 16 years, a magnitude 4.0 tremor that was centered deep in the earth's crust just northwest of  Poplar Bluff, MO. 

A seismograph from  Lake Charles, AR clearly recorded the motion of the earthquake. (USGS)

While certainly not as strong as the quakes that caused the Mississippi River to "flow backwards" in the winter of 1811-1812, reports were quickly received of jolts and rumbles across the metro. The last time a quake this strong occurred on the New Madrid fault was May 1, 2005, a magnitude 4.2 centered near Manila, AR, east of Jonesboro. 

The community-based "shake map" clearly shows the earthquake was felt over a large area. (USGS) 

More information on the earthquake, as well as a page that allows you to report if you felt it, can be found on the event page from the U.S. Geologic Survey. So while it was a noticeable event for many in the metro, it is a reminder that we live on the southern edge of an active fault and should be prepared, just in case. This time, we're simply glad that it wasn't any worse... and hoping it is not a pre-shock to "the big one."



Erik Proseus
MWN Meteorologist

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Follow MWN on Facebook and Twitter for routine updates and the latest info!
Complete MWN Forecast: MemphisWeather.net on the mobile web or via the MWN mobile app
Download our iPhone or Android apps, featuring StormWatch+ severe weather alerts!
MWN is a NOAA Weather Ready Nation Ambassador Meteorologist Erik Proseus is an NWA Digital Seal Holder