Sunday, December 27, 2020

Wet weather to finish out 2020, details on winter weather potential

Following a very cold Christmas Eve and Christmas Day (the coldest Christmas in Memphis in 20 years actually!), the weekend has proven to be just delightful. After topping out just above freezing Friday, we saw 20 degrees of warming Saturday, into the mid 50s, and another 10 degrees of warming today as the mercury reached the mid 60s on a strong and gusty south wind! The New Year's week forecast, though, shapes up to be rather active as the next big storm system brews to our west.

Early week tranquility

A fast-moving cold front slices through the Mid-South tonight, but with limited moisture, only scattered showers with light rainfall amounts are expected tonight. Temperatures will be back down in the 50s Monday with dry conditions but high clouds overhead and much less wind. The same general conditions are expected on Tuesday with lows above freezing and highs in the mid 50s - overall a bit above normal. Wednesday things start to get interesting...

Sunday afternoon HRRR model showing what it thinks radar may look like from 6pm to 6am tonight. Scattered light showers are most likely in the evening hours. (WeatherBell)


Strong winter storm setup

We are closely watching the next big weather maker for the Mid-South, which will move into the area on New Year's Eve. This system, as of Sunday afternoon, is still over the Pacific moving east and will move onshore late tonight.  It will then move east across the southwestern US during Monday and Tuesday, and will be located across the Southern Plains on Wednesday, with everything from thunderstorms and potential severe weather across Texas and Oklahoma, to winter weather across the Central Plains and snow all the way up to the Canadian border.

Forecasted surface features from WPC valid for Tuesday evening (NOAA/NWS)

Last few days of 2020

By Wednesday morning, the cold front will be located from the Midwest into Texas, with precipitation along and ahead of the front from Lake Michigan into Oklahoma and Texas.  During the day Wednesday, we should begin to see rain a few showers across the area as the front pushes east.  By Wednesday night into Thursday morning (New Year's Eve), rain will be ongoing as the cold front pushes into the Mid-South but stalls.  An area of low pressure will form along the cold front in Louisiana, and ride northeast along the front Thursday, moving into the Mid-South Thursday evening.  This is where things get... complicated.




Wet weather starts the New Year

Thursday evening we will see rain showers, with a few thunderstorms mainly across northern Mississippi in the more unstable and warm air.  As we ring in the New Year, rain will be moving over the region with winter weather across eastern Oklahoma, western Arkansas and southern Missouri.  The showers over the Mid-South will be tapering off towards daybreak Friday, while snow showers may be ongoing across north-central Arkansas and the Missouri Bootheel.  Total rainfall amounts from Wednesday evening thru early Friday afternoon for the Mid-South will be 2 to 3 inches, with isolated amounts of 4 inches. Yeah, it'll be a soaker!

European model surface map when the guitar drops on Beale Street - 12am Friday (PivotalWeather)

Questions and concerns

At this point, we cannot rule out the potential for snow showers across portions of the Mid-South Thursday night or early Friday, with little to no accumulation.  However, the low is forecasted by most models to stay just to our west in Arkansas as it pushes northeast, keeping the cold air and winter weather potential to our west on the "backside" of the low.  The main complication will be if the front moves thru quicker than forecasted, which would bring that winter weather in Arkansas closer to the Mid-South.  This scenario seems to be less likely, at least at this time. (You all know that forecasting winter weather 4-5 days in advance though can be a little tricky! Don't give up hope just yet!)



Clearing out on Friday
By noon on Friday, rain should be well out of the area, with decreasing clouds, breezy southwest winds and temps in the mid 40's.  The weekend looks dry, with highs in the mid to upper 40's, and lows in the upper 20's - not far from average for the first of January. So if you're looking for snow to ring in the new year, you will be better off traveling to the Ozarks!



Richard Hoseney
MWN Meteorologist

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Monday, December 21, 2020

Winter officially arrives today, but cold winter air waits until Christmas. How about winter precip?

Quick outlook

Pleasant weather for the first half of the week, rain chances Wednesday, then clear and cold for Christmas.

First half of the week

As winter officially arrives (Monday morning at 4:02am), Monday thru Wednesday will be nice with a return of southerly winds which will bring highs near 60.  Skies will be clear for Monday and most of Tuesday, with increasing clouds Tuesday night.  By Wednesday morning, a cold front will be located from Minnesota and south into the Southern Plains, with rain chances increasing as the front pushes east into more humid conditions across the lower Mississippi Valley.

Wednesday morning surface map

Wednesday cold front

This front will push into the Mid-South Wednesday around sunset with rain chances and windy conditions arriving Wednesday, particularly in the afternoon and evening.  Behind the front, much colder temperatures will quickly push in on a cold northwest wind.  There also will be the potential for some winter weather in far northern Tennessee, but any winter precipitation would be light and not likely to affect the metro. Expect rainfall to diminish by midnight Wednesday night before the coldest air arrives. 



Christmas Outlook

As documented on this blog previously, a White Christmas is extremely rare in Memphis. And this year, despite the chill, will not buck the "sNOw" trend. Christmas Eve (Thursday) and Christmas Day (Friday) will be much colder than the temperatures we will have had in the first part of the week, with highs near 40 and lows near freezing Thursday morning and in the low 20's Christmas morning.  It will be clear, with no precipitation in the forecast.  So Santa will have clear skies and chilly weather as he makes his trip thru the Mid-South!


Weekend outlook

Thankfully, the weekend will be a bit warmer. Saturday will see highs pushing 50 degrees under sunny skies after sub-freezing morning lows. Sunday will be a bit warmer (in the 50s) but with rain chances again as the next frontal system arrives.


Richard Hoseney
MWN Meteorologist

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MWN is a NOAA Weather Ready Nation Ambassador Meteorologist Erik Proseus is an NWA Digital Seal Holder

Thursday, December 10, 2020

Unusually warm weather turns wet & cool soon!

Warm & sunny feels good!

Warmer than normal temperatures continue for the Mid-South, thanks to a ridge of high pressure that is to our east.  This means we'll continue to see warm southerly winds today and Friday that will lead to above normal temperatures.  Highs will peak just above 70 today, with clouds moving in late Thursday night, followed by cloudy skies and highs in the mid 60's on Friday.

Those highs are roughly about 15-20 degrees warmer than normal, with the normal high this time of year at 53 degrees. A large portion of the eastern US is currently warmer than normal, as show in the graphic below for highs on Thursday (shown in numbers) and the departure from normal (color fill).

Max temperatures & departure from normal (NWS/WPC)


But...

Changes are coming Friday night as a cold front, currently stretching from the Northern Plains to the Rockies and Desert Southwest, will push into the Mid-South.  This will bring rain to the area by Friday evening that should end early on Saturday.  Precipitation amounts will likely be near or below 1/2" with no thunder expected. Highs Saturday will be near 60 with a westerly breeze. With this system gone, it appears the Memphis Tiger football team's season-ender at the Liberty Bowl Saturday afternoon will be dry with temperatures near 60! Go Tigers!

Forecast surface map valid for Friday evening.

Cooler weather begins to move in Saturday evening, and on Sunday highs will only reach the upper 40's to near 50.  There is also another chance for rain Sunday afternoon/evening as a fast moving disturbance moves through north MS.  Most models are on board with this solution, which is a good thing.  If this precipitation slows down and arrives late Sunday evening, there would be the possibility of winter weather (and very light amounts at that).  But as it stands right now, only liquid precipitation is expected.

Next week

Temperatures for next week look to be near or slightly below normal, with highs in the mid 40s to near 50 and lows in the 30's. So enjoy the warm weather while it lasts!  This may be the last reprieve from cooler weather we'll get for a quite a while!



Richard Hoseney
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
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MWN is a NOAA Weather Ready Nation Ambassador Meteorologist Erik Proseus is an NWA Digital Seal Holder

Monday, December 7, 2020

November 2020 Climate Data for Memphis, TN

November Climate Recap

After a cool and somewhat wet October that was marked by two passing tropical systems, November swung towards warm and dry. All but seven days averaged above normal temperature-wise with seven of those above average days at or above 10 degrees above normal, including a high of 82 on the 8th. In fact, the average high temperature for the month ended up 7th warmest on record, while the average temperature for the month was in the top 10% of all Novembers on record. The month ended cold though, with highs in the 40s on the 29th and 30th, a low of 28 on the 30th, and even a trace of snowfall that day behind a cold front on the 29th. Only four days had rainfall totals of more than 0.01" and no days with more than an inch, resulting in a monthly total at 32% of normal. There was no severe weather during the month and no warning issued.

Memphis International Airport, Memphis, TN

Temperature 
Average temperature: 56.4 degrees (3.2 degrees above average) 
Average high temperature: 67.2 degrees (4.6 degrees above average) 
Average low temperature: 45.6  degrees (1.9 degrees above average) 
Warmest temperature: 82 degrees (8th) 
Coolest temperature: 28 degrees (30th) 
Heating Degrees Days: 273 (95 below average)
Cooling Degree Days: 23 (10 above average) 
Records set or tied: None 
Comments: The average high temperature for the month of 67.2 degrees was 7th warmest on record.

Precipitation 
Monthly total: 1.74" (3.75" below average) 
Days with measurable precipitation: 5 (4.5 days below average) 
Wettest 24-hour period: 0.78" (25th) 
Snowfall: Trace 
Records set or tied: Record daily snowfall tied - Trace (30th / 1974)
Comments: None.

Miscellaneous 
Peak wind: West/43 mph (15th) 
Average wind: 7.4 mph 
Average relative humidity: 62% 
Average sky cover: 38% 

 Click here for a daily statistical recap for Memphis International Airport.
 

Cirrus Weather Solutions / MemphisWeather.net, Bartlett, TN

Temperature 
Average temperature: 54.3 degrees 
Average high temperature: 66.8 degrees 
Average low temperature: 42.5 degrees 
Warmest temperature: 80.5 degrees (8th) 
Coolest temperature: 27.2 degrees (30th) 
Comments: None 

Precipitation 
Monthly total: 1.69" (automated rain gauge), 1.80"(manual CoCoRaHS rain gauge) 
Days with measurable precipitation: 5
Wettest date: 0.60" (25th) (via automated gauge) 
Snowfall: Trace 
Comments: Snow flurries were recorded on the morning of November 30

Miscellaneous 
Peak wind: South/33 mph (25th)
Average relative humidity: 73% 
Average barometric pressure: 30.17 in. Hg
Comments: None

Click here for a daily statistical recap for Bartlett, TN.
 

MWN Forecast Accuracy

MWN average temperature error: 2.08 degrees 
MWN forecast temperatures within 2 degrees of actual: 67% 
MWN average dewpoint error: 2.38 degrees 
MWN forecast dewpoints within 2 degrees of actual: 67% 

MWN's forecasts extend out five periods (2.5 days, or roughly 60 hours). Historical accuracy statistics can be found here.
 

Climate Outlook - December 2020

The December climate outlook for the United States from the Climate Prediction Center is shown below. Above average temperatures are forecast for much of the United States, with highest probabilities in the Great Plains. Odds favor near average temperatures for Memphis, with a 34% chance of above normal and 33% chances of below and near normal. The average temperature for December is 43.6 degrees, or about 10 degrees cooler than November.



Precipitation is expected to be below normal across much of the U.S. in December with the exception of the Northeast. Near average precipitation is forecast for the Northwest and Appalachian Mountains into Florida. For Memphis, odds favor below average rainfall (a 46% chance) versus only an 21% chance of above average rainfall. Precipitation historically averages 5.74 inches, making December typically the wettest month of the year. 

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MWN is a NOAA Weather Ready Nation Ambassador Meteorologist Erik Proseus is an NWA Digital Seal Holder

Tuesday, December 1, 2020

Another chance for winter weather this week?

With our first "winter weather event" (cold rain Sunday and flurries Monday) behind us, but cold air still in place, it's time to look ahead to the next weather maker that will move into the region. We'll dissect the chances that additional winter weather might occur in today's blog.

Upper level features

An upper-air trough of low pressure will push into the Central and Southern Plains over the next couple of days, and will become cutoff from the main area of the jet stream that is over central Canada.  The jet stream will begin to push east over the northern Great Lakes, eventually merging with in an area of low pressure currently over the Northeast US that will be located over northeast Canada on Friday.  The cutoff low over the Central and Southern Plains will slowly move east and over the Mid-South this weekend.

Jet stream forecast valid for Thursday night (GFS model)


Surface weather

At the surface, a low pressure system will develop over the Southern Plains on Wednesday, and moisture from the western Gulf of Mexico will begin to be pulled into the low, with rain occurring from eastern Texas into Oklahoma and snow likely in western Oklahoma. 


Surface features valid for Wednesday afternoon (NWS/WPC)


Starting to our north...

On Thursday, the low will move east into Arkansas, and the associated precipitation will move into Missouri, Arkansas and Louisiana, with some mixed precipitation expected early Thursday morning over southern Missouri and possibly northern Arkansas and far northwest Tennessee where temperatures will be in the low to mid 30's.  We will likely see some sleet or graupel ("dippin dots") reports over northern Arkansas and northern Tennessee early Thursday, much like we did on Sunday at the onset of the precipitation, as there will be a layer of dry air in the lower levels of the atmosphere.

Upper air sounding forecast for northeast AR for late Thursday night.


Forecast precipitation type for early Thursday morning (European model)

Closer to home...

For the Memphis area, scattered light rain showers will begin to move into the area early Thursday morning, followed by steadier rain showers around daybreak, with temperatures near 40, which will result in all liquid precipitation for the Memphis area.  This rain should end by early Friday morning as the upper low begins to move over the area and forces the precipitation to our east.

As this low moves east of us on Saturday, the potential for wraparound moisture increases, as temperatures drop into the mid 30's.  This could bring about another chance for a few snow flurries Saturday morning for the Mid-South, which wouldn't be anything to worry about. This would be very similar to what we saw on Monday. Any flurries should come to an end Saturday afternoon as dry air moves in and clouds clear out.

Dry weather looks to continue all next week, with rain chances returning for the weekend (12th & 13th).  So no snow day just yet, kids (and adults)!



Possible alternate scenarios

The only discrepancies I see right now is the timing of the low moving thru the region.  The European model is much faster, and has the low east of us by Friday night, while most of the other models have the low still over Arkansas.  The main issue with that is the timing of the precipitation ends Thursday night according to the European model, and the consensus of the other models have the precipitation ending early Friday morning.  However, the European model has had a tough time trying to figure out where the low will be over the past few days, so I've sided with the consensus of the other models on the timing of the precipitation moving out.  As far as the onset of precipitation and type, the European and other models have pretty good agreement.

Richard Hoseney
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
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MWN is a NOAA Weather Ready Nation Ambassador Meteorologist Erik Proseus is an NWA Digital Seal Holder