It May Snow Next Weekend

Sunday – Clouds, Maybe a Light Evening Sprinkler – Morning Low 33, Afternoon High 54

6am 34 . 9am 41 . Noon 50 . 3pm 53 . 6pm 49 . 9pm 46

Here’s your FutureCastSometimesWrong Radar (aka, the 4km Hi-Res NAM), Noon to 8 pm. Not much rain, if any:

Monday – More Clouds, Slight Rain Chance – Morning Low 33, Afternoon High 54

Next Weekend

We usually don’t post model data 7 days out, because it’s so far out in the future and is rarely meaningful. But @12SouthWintWarm has their beer festival next weekend, and I told them we’d have a look. And, then, our NWS started talking about it. So will we.

IMPORTANT NOTE WHEN USING WEATHER MODELS: Models are tools, not forecasts. Models predict conditions 7 days away. Allow 4 to 6 weeks for delivery. For entertainment purposes only. Avoid contact with skin. Call before you dig. Contains phenylalanine. May induce vomiting. Do not use if pregnant. Fragile. Also, Italian. Your results may vary. Keep left. Not valid in all areas. Open other end. Proceed with extreme caution.

Check out the Possibly-Wrong-FutureCast Radar (GFS version) for Friday night:

Check out this explanatory gif from our local NWS office:

Officially, the NWS thinks there will be a “brief changeover to sleet and snow as early as Friday night. The winter potential seems rather harmless this far out, but the very pattern of a strong positive upper ridge axis over the Carribbean combined with a strong southward moving surface high does bear watching.”

Translation: it may snow next weekend.

Warm Saturday. Very Slight Chance Of Rain Sunday

Tonight – Mostly Clear  Overnight Low 28

6pm 42 . 9pm 37

Considering how cold we have been lately, we can’t ask for much better shopping/travel weather.

image_full10

Saturday – Sunny – Morning Low 28, High 56

6am  29 . 9am 39 . Noon 51 . 3pm 54 . 6pm 47 . 9pm 42

This will be the warmest day we will have had in a long time. You will think it actually feels nice outside. (At least I think you will.)

Sunday – Partly Sunny – Morning Low 34, High 53

6am 35 . 9am 42 . Noon 51 . 3pm 54 . 6pm 48 . 9pm 44

In exchange for no temperatures below freezing, we’ll see increased clouds and a small chance of rain.

Official NWS Forecast:

Screen Shot 2013-11-29 at 2.43.01 PM

Questions? We’re on Twitter @NashSevereWx.

Happy Thanksgiving, Y’all! Clear, Bit Warmer…But Still Cold

Thanksgiving – Cold But Warmer  Overnight Low 23

 3pm 40 . 6pm 34 . 9pm 30 . 12am 28

Happy Thanksgiving from David (Best Boss-Man Ever!), Will (Thankful I’m not washing his Jeep anymore!), and me (The Intern)! Hope you are cherishing the time you have with family, friends, and all the blessings in your life!

image_full10

Black Friday – Clear, Cold, But Warming Up – Morning Low 23, High 51

6am  24 . 9am 34 . Noon 46 . 3pm 49 . 6pm 42 . 9pm 38

Good shopping weather.

Saturday – Sunny – Morning Low 29, High 56

6am 30 . 9am 40 . Noon 51 . 3pm 55 . 6pm 48 . 9pm 44

The warmest day of the week. Enjoy it, because it won’t last long. December temps will be well below average!

Official NWS Forecast:

Screen Shot 2013-11-28 at 12.58.06 PM

Questions? We’re on Twitter @NashSevereWx.

Serenity Now! “Straight Fridge.” “Wind Shield” Gaffe Advice

Too cold to go outside for a break from loved ones? 

Hope that helped. You are not alone.

(Editor’s Note: I do not feel this way about my visiting in-laws. They’re awesome! Really, I mean that, Ju-Ju!)

Tonight – Cold & Windy  Overnight Low 18

Today’s wind chill hovered in the upper teens/low 20s (it thinks it knows everything).

Ever wonder how we come up with “Wind Chill” or the “Feels Like” temperature? We have a chart! (Editor’s Note: I google it and use a calculator. Ironically, it’s The Intern who is old school).

Screen Shot 2013-11-27 at 3.22.58 PM

Bet you did not need a chart to tell you that it is “straight fridge” today!

(Editor’s Note: I had to put quotes around “straight fridge.” That’s one of those phrases I’ve never heard before, which I love, but am too old to say and be cool. Word!).

(Another Editor’s Note: if you thought it was “wind shield” factor, like this guy:

please don’t admit it. Just make a mental note and keep it secret. No one has to know. If you’ve said “wind shield” factor to loved ones, next time you have a chance to use the phrase, gradually make the shift. I recommend saying “windshfactor” really fast at first. Then, at your next opportunity, use “winshill.” Finally, “windchill” then “wind chill.” Your loved one will think: “he/she has been saying ‘wind chill’ all along! I misheard!”)

The winds will finally die down tonight, but if your freezer is crowded, you can leave your stuff outside.

Thanksgiving – Clear, Cold, But Warming Up – Morning Low 18, High 43

6am 19 . 9am 28 . Noon 39 . 3pm 42 . 6pm 35 . 9pm 31

Friday – Sunny – Morning Low 23, High 49

6am 24 . 9am 34 . Noon 45 . 3pm 47 . 6pm 40 . 9pm 36

Official NWS Forecast:

Screen Shot 2013-11-27 at 3.27.44 PM

Our next chance of rain arrives Sunday.

Questions? We’re on Twitter @NashSevereWx.

My Reaction to the Winter Weather Advisory Being Cancelled

This is me about an hour ago . . . “Today we’ve had 1″ of snow forecast. Winter Weather Advisory. Models supporting snow.”

And then . . . 

Here’s why I destroyed my computer:

(1)  Radar Trends. As @RuthSevereWx says, there is “squadoosh” happening to our south, west, and southwest:

(2)  Models. Check out the HRRR from 6 p.m. to 2 a.m.:

Green/Gray = rain. Blue = snow.

Maybe a drive-by dusting around/after midnight. Certainly no travel worries. Other models saying “we don’t think so.”

And now, as I’m writing this, here comes the cancellation of the Winter Weather Advisory:

In case you can’t see it, this says:

LITTLE OR NO SNOWFALL IS EXPECTED THROUGH TONIGHT.

We feel ya, Charlie Brown.

Wednesday – Cold & Windy – Morning Low 23, High 31

6am 24 . 9am 26 . Noon 30 . 3pm 30 . 6pm 26 . 9pm 24

Wind Chill of 10 degrees in the morning!

Travel should be OK, although be careful in the morning. Dry air and high winds should hopefully clear your path to grandma’s.

No need to freeze your turkey. Just leave it outside.

Thursday – Mostly Sunny – Morning Low 19, High 41

6am 20 . 9am 28 . Noon 37 . 3pm 40 . 6pm 34 . 9pm 30

Warming up a bit. No weather or travel concerns.

Official NWS Forecast:

Screen Shot 2013-11-26 at 4.00.39 PM

Questions? We’re on Twitter @NashSevereWx.

 

Tonight: sNOw? YESnow? What We (Think We) Know:

Today – *Winter Weather Advisory* – Snow? Windy & Clearing  Overnight Low 23

image_full11

Timing from our NWS remains unchanged:

image8

The Winter Weather Advisory remains in effect:

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This NWS graphic thinks we will see 1.0″ of snow:

So, there’s that.

Then there’s the HRRR model (19z) for today from 4 pm – 1 am: (Blue  = Winter Precip, Green = Rain):

According to this, very little snow is expected, but to be fair, the HRRR has been waffling a bit all day long.

There is nothing impressive on the radar to our south or southwest to give me any confidence of 1″ of snow. All the good moisture has escaped east. However, water vapor imagery shows there’s still some moisture to work with before the system departs tomorrow:

There’s plenty of evidence to support a sNOw or a YESnow. The safest bet is that the roads are wet, the temp will drop substantially below freezing after dark, and black ice is a travel concern. Also, there will be a strong wind tonight. You don’t want to be outside. Wind chills will fall into the teens before 9 p.m. tonight.

We’ll be on Twitter @NashSevereWx providing updates the rest of the night.

Wednesday – Any Snow: Gone. Cold & Windy – Morning Low 23, High 31

6am 24 . 9am 26 . Noon 30 . 3pm 30 . 6pm 26 . 9pm 24

Wind Chill of 10 degrees in the morning!

Travel should be OK, although be careful in the morning. Dry air and high winds should hopefully clear your path to grandma’s.

No need to freeze your turkey. Just leave it outside.

Thursday – Mostly Sunny – Morning Low 19, High 41

6am 20 . 9am 28 . Noon 37 . 3pm 40 . 6pm 34 . 9pm 30

Warming up a bit. No weather or travel concerns.

Official NWS Forecast:

Screen Shot 2013-11-26 at 4.00.39 PM

Questions? We’re on Twitter @NashSevereWx.

Snow Update: An “Unfrozen Slush,” Travel Concerns Tonight

Remember this?

Lucy tells Charlie Brown she’ll hold the ball, only when he comes up to it, she pulls it away? Looks like this may be happening to the sled-able snow we thought we could be getting early this morning.

(The above gif idea came from the weather forum tennesseewx.com. Full credit to “bugalou” for posting it).

It’s all a big “maybe.” Rather than snow, we will probably see a mixed bag of wintry precip, culminating in an “unfrozen slush.” Keep reading.

Our NWS, speaking about all of Middle Tennessee, had this to say just after 11 a.m. this morning:

We believe the main impact will be an unfrozen slush during the afternoon and evening hours, but then transitioning to a more dangerous period later in the evening and overnight (especially on untreated bridges and overpasses) when temperatures fall into the 20s and remaining moisture could easily freeze and produce patchy black ice.

Officially, for Davidson & Williamson Counties, our NWS opens a rain/sleet/snow window beginning at 3 p.m., and closing around 9 p.m. Snow is more likely between 5 p.m. and 8 p.m. It all should all be over well before Wednesday morning.

Then there’s the HRRR.

The HRRR is a short-range weather model. It’s not perfect, but I respect it like Alabama fans respect Bear Bryant. It updates every hour, bringing us a fresh batch of data of what it thinks will happen over the next 15 hours.

Early this morning, the HRRR predicted a healthy snow starting around dark; however, several runs mid-morning pulled most – but not all – of the precip east before the snow-making temps filtered in. This does not mean we will get nothing, but I’d put away my sled (it’ll be dark, windy, and no fun).

Here’s the latest (15z) run of the HRRR, from noon until 9 pm tonight (green is rain; blue/red is snow):

This is not an impressive snow event, but it’s not nothing. In fact, the HRRR even has another little strip of snow coming through at midnight.

Other weather models (like the WRF) wrap in some snow along and east of I-65 tonight. Others (like the NAM) have it snowing juuust off to our east, missing us completely. This is a very, very close call for us.

Travel issues are possible, if not likely, tonight. Temps are going to crash below freezing after 6 p.m. A strong north wind will drop wind chills into the upper teens (officially, the wind chill is forecast to be 17 at 9 p.m.). Anyone going east on I-40 should pay particular attention. If you can travel out that way tomorrow, that may be better.

Our Winter Weather Advisory remains in effect:

Do not rely on this webpage as your only source of updated info. Brand-new information will be found on Twitter @NashSevereWx. As always, consult multiple weather sources before making decisions.

Overnight Snow/Rain Details; More Rain, Possibly Some Snow, Tomorrow

Today – Snow/Sleet/Rain  Low 34 Tonight/Overnight, 33 by 6 a.m. Tomorrow

We thought we would see rain and sleet. Instead, we got snow sticking to grass, but not roads. Here’s a good picture from @gencarter: “@NashSevereWx snow in downtown Nashville, just west of the Capitol”:

BZ8qAx4IgAATAhd.jpg-large

Right now it’s 34 (above freezing) and sleeting/snowing/raining. We are not forecast to reach 32 tonight. Travel should be OK, but stay tuned (we’ve been fooled before), and be careful on bridges and overpasses.

Take note how the HRRR model (below) changes the snow to rain tonight. Why? Winds are coming from the south. We are warming!

HRRR model Monday 4 pm – Midnight: (Blue  = Winter Precip, Green = Rain):

Tuesday – Rain/Snow/Sleet – Morning Low 33, High 40

6am 33 . 9am 36 . Noon 39 . 3pm 39 . 6pm 34 . 9pm 31

Looks like this will mostly be a rain event, but we can’t rule out more winter precipitation mixing in with the rain. This is especially true late Tuesday afternoon and evening. No accumulation is expected, but grassy surfaces may be assaulted again.

Hi-Res NAM model Tuesday 5 am – 2 pm (we are in the very center of this radar loop):

The WPC forecast is for about .5″ of rain through Wednesday 6 a.m.:

hpc_total_precip_se_8

Wednesday – Mostly Sunny – Morning Low 25, High 33

6am 26 . 9am 28 . Noon 32 . 3pm 32 . 6pm 27 . 9pm 24

Another fiercely cold day!

Official NWS Forecast:

Screen Shot 2013-11-25 at 3.24.06 PM

Questions? We’re on Twitter @NashSevereWx.

NWS Special Weather Statement on Sleet Monday, Snow Tuesday Night

This afternoon, our NWS issued a Special Weather Statement for Middle Tennessee, including everyone in Davidson and Williamson Counties. It’s quoted in blue, below.

In short, the answer to the question: will it snow?

A quick review of the difference between Rain, Freezing Rain, Sleet, and Snow. This helps explain why wintry precip occurs even when it’s above/near freezing at the surface:

 

Monday – Rain/Sleet – Morning Low 25, High 41

6am 27 . 9am 32 . Noon 39 . 3pm 40 . 6pm 38 . 9pm 37

A weather disturbance in the southern plains (currently seen here):    

will bring a round of light rain mixed with sleet beginning Monday afternoon and continu[ing] through Monday night.

Tuesday – Light Evening Snow Possible – Morning Low 34, High 42

6am 34 . 9am 37 . Noon 41 . 3pm 41 . 6pm 36 . 9pm 32 . Midnight 30

Precipitation will be mostly light rain during the day on Tuesday before changing to light snow Tuesday night with minor accumulations possible along the plateau. Light snow will end from the west early Wednesday.

Note: the NWS “accumulating snow” forecast is for the plateau, not for us.

But, I thought it would be fun (of course I did!) to review the models and see what they say about snow chances for us:

 

These models change. A lot! They’re not forecasts, but they’re saying there is a chance.

Tomorrow morning, we’ll have the benefit of the Canadian and WRF models, which will finally get in range of a Tuesday night snow event.

Travel looks pretty good Wednesday. Thanksgiving will be cold and clear.

Questions? We’re on Twitter @NashSevereWx.

 

Next Few Days: Cold, Rain, Sleet, Snow, But No Accumulation Expected

Today – Plenty of Sun, but COLD  High 36

Temps (Wind Chills)

9am 28 (16) . Noon 34 (25) . 3pm 35 (28) . 6pm 31 (26) . 9pm 28 (22)

Winds will be strongest this morning and early afternoon, keeping those wind chills low.

image5

Monday – Precip Chances Increase – Morning Low 23, High 43

6am 24 . 9am 31 . Noon 40 . 3pm 42 . 6pm 39 . 9pm 37

South winds arrive, which will

(1)  warm us up, and

(2)  transport clouds and moisture.

A northeast-moving rainmaker will move south of us. The northern edge of it may graze Middle Tennessee, mostly while we are above freezing.

So, right now we think this will be a rain event with some winter precipitation mixing in at times. No accumulation of anything expected.

The models illustrate this:

NAM

GFS

By the way, wondering about the difference between snow, sleet, and freezing rain? Rick Smith (@ounwcm) shared this helpful graphic:

 

Tuesday – Rain/Sleet/Snow? – Morning Low 33, High 41

6am 34 . 9am 36 . Noon 40 . 3pm 40 . 6pm 35 . 9pm 31

Another typical iffy chance of snow. Too much can go wrong to say anything with confidence. Chances appear very low right now, but for what little it’s worth, the European model has us down for under an inch of snow.

Official NWS Forecast:

Screen Shot 2013-11-24 at 7.24.00 AM

Questions? We’re on Twitter @NashSevereWx.