Sunday, December 25, 2011

Merry Christmas

Merry Christmas!

- Posted from my iPhone

Wednesday, December 21, 2011

No Snow

Snow chances are pretty much gone for the weekend.

European model tries to bring an upper-level cold core low through southern Missouri, southern Illinois, Kentucky and southern Indiana December 28. That could bring a little snow but don't bust out the shovels just yet.

Tuesday, December 20, 2011

Christmas Eve Snow Update

Just a quick update to give you the latest on what the computer models are showing for Christmas Eve.

All of the models have dried up the atmosphere for December 24. Temperatures will be cold enough in the atmosphere, however with no moisture, we won't get anything to fall. Bottom line, the chances for snow on Christmas Eve is looking pretty slim for Missouri, Illinois, Indiana and Kentucky.

The only hope if you want snow is this morning's European Weather Agency's forecast model. It hinted at some overrunning moisture for the Missouri bootheel and western Kentucky Christmas morning. If that were to pan out, there could be maybe a dusting to a half inch of snow by Christmas afternoon. That being said, I wouldn't hold your breath just yet.

Monday, December 19, 2011

Flakes for The Holidays

"Am I going to have a White Christmas?" That is the question I am most asked this time of year.

As is usually the case, it just depends on where you live. If you live in Colorado, Oklahoma, Texas or Kansas you could definitely have a "WhiteChristmas". Blizzard-like conditions are expected later today.

(Click the image to see a larger version.)

Weather data coming in from morning computer models indicates over a foot of snow could fall in some of the above mentioned locations. National Weather Service forecasts are calling for up to 15" of snow over southwest Kansas and northwest Texas.

Meanwhile, we're waiting to see if any snow will introduce itself in the forecasts for the Midwest.

This time of year there are "typical" storm tracks that will favor snow accumulation.

(Click the image to see a larger version.)

Typically for there to be a big accumulating snow storm for southeast Missouri, southern Illinois and western Kentucky we need a storm to track just south of the "Mississippi Valley" line shown above.

This means we're looking for low pressure systems to move from Dallas to the east/northeast.

Later this week models are now hinting at the possibility for a few snow flurries or snow showers to be flying through the skies of the Midwest.

(Click the image to see a larger version.)

The storm that will bring the precipitation will form along the gulf coast and take more of a "Nor'easter" track, similar to what is shown in the above Storm Tracks map.

Models are suggesting that moisture will ride far enough north that some of it could fall as snow in east/southeast Missouri, Illinois, Indiana and Kentucky. Right now, amounts look minimal. Perhaps just flurries to a dusting in most locations. Although, a few spots, like Indianapolis, could see a half inch of snow. A lot of the fine details have yet to be shown.

(Click the image to see a larger version.)

The above map shows where Accuweather forecasters thinks there could be snow for the weekend. I think they may need to drop the snow line a little further south over the KFVS viewing area.

That being said, the chances for a "White Christmas" seems relatively small for all of the areas described above. A "White Christmas" is defined as having 1 inch of snow measured on Christmas day. I don't think we'll see that much.

A lot will likely change in the forecast between now and the weekend so stay tuned to the forecast. Also, remember to follow me on Twitter (@johndissauer) for more frequent updates.

- Posted from my iPhone

Friday, December 16, 2011

Signs of Snow

There are signs that snow may arrive to parts of the Midwest early next week.

For several days forecast models have been hinting at a storm developing over the southwest United States, eventually moving through the Midwest. The models haven't been jiving too well with each other to the course the storm will take. If you follow me on Facebook you might remember a status update that said, "Models are flip flopping around..."

Last night's runs started coming together and this morning's model runs are pretty similar in to the track of the surface low. (See graphic below.)

(Click image to see larger version.)

The above graphic was created by AccuWeather but is pretty close to what the models are showing regarding the track of the storm.

Northwest of the surface low cold air is expected to move in. This will allow for some significant snowfall in parts of the country.

It is interesting to compare the amount of moisture north of the surface low that could interact with the cold air and fall as snow. Models are not on the same page with this feature.

The European forecast agency's computer model is more bullish on the liquid amounts compared to NOAA's computer model. Here's a closer look at what the models are indicating for liquid available during the time it would fall as snow.

European Model:
  • Kansas City - 0.77"
  • Kirksville, Mo - 0.44"
  • Columbia, Mo - 0.09"
GFS Model:
  • Kansas City - 0.09"
  • Kirksville, Mo - 0.03"
  • Columbia, Mo - 0.00"
If the European model is correct, Kansas City could end up with 6"-9" of snow (maybe more). If the GFS is correct Kansas City could get 1" of snow. That is a pretty big difference.

I should mention that areas along and south of the track of the surface low will see good ole' rain.

Stay tuned...

- Posted from my iPhone

Wednesday, December 14, 2011

One Year Ago

The snow has been pretty much nil for much of the Midwest this winter. I'm hoping we start to see the action pick up soon but looking at computer models for the next two weeks it isn't looking too promising.

It is interesting to look back to a year ago and compare this year to last year's snow cover.

Take a look at the image above. (Click the graphic to see a larger version.). There's a pretty dramatic difference.

According to the National Operational Hydrologic Remote Sensing Center, 24.6% of the United States is covered by snow. Contrast that to 2010 and on this date 38.4% of the country was covered by snow. That's a 36% decrease in snow cover! Take that back to 2009 and it's even more dramatic as 48.7% of the country was covered.

Temperatures were also a lot colder last year. Minimum temperatures on December 14, 2010 was 1° in Carbondale, 4° in Indianapolis and Paducah, 7° in Cape Girardeau and St. Louis. Instead this year temperatures are in the 50°'s.

- Posted from my iPhone

4:00pm CT Update: I was curious when the last time we had such a small amount of snow on the ground so I went back and looked at December 14 going back several years.

United States Covered by Snow
  • 2011 - 24.6%
  • 2010 - 38.4%
  • 2009 - 48.7%
  • 2008 - 40.9%
  • 2007 - 50.2%
  • 2006 - 13.2%
You can see that today is the least amount of snow cover (for this day) in the last 5 years.

Wednesday, December 7, 2011

Snow Totals from Dec. 7

Snow fell across parts of Arkansas, Missouri, Kentucky, Tennessee and Mississippi overnight.
I have to admit, I am pretty happy with how my snow forecast turned out.

Here's a look at some of the totals that were turned in to the National Weather Service.

  • Blytheville 2"
  • Jonesboro 1"-2"
  • Cooter 2"
  • Hornersville 2.75"-3"
  • Covington 2"
  • Dyersburg 1"
  • Jackson 1.5"
  • Memphis 1"-2"
  • Union City 1"
Did you have snow where you live this morning? If so, tell me how much in the comments section. *Remember, measuring snow on the grass doesn't work as it includes air/mud/dirt in the total.

It is kind of strange this season how Memphis, Tennessee has had more snow that St. Louis. I hope that changes soon. I'd like to get a couple of good snows!

Tuesday, December 6, 2011

Wednesday Snow Part 3

Looking over some of the new data that is coming in tonight.

So far, data from just one of the models (the NAM) is in. The model seems to be coming in slightly wetter than earlier today. Snow to liquid ratios could be anywhere from 12:1 to maybe 16:1. The 16:1 may be pushing it a little because we aren't that cold at the surface. However, a 1,500' thousand feet up in the air we are -5 degrees Celsius.

Here is what the model is suggesting for moisture available and the potential snow using the ratios above.

CITY | Liquid | Snow (12:1)/(16:1)
  • Blytheville, AR - 0.14" | 1.6" / 2.2"
  • Cape Girardeau, MO - 0.02" | 0.2" / 0.3"
  • Dyersburg, TN - 0.16" | 1.9" / 2.5"
  • Jackson, TN - 0.17" | 2" / 2.7"
  • Jonesboro, AR - 0.16" | 1.9" / 2.5"
  • Murray, KY - 0.05" | 0.6" / 0.8"
  • Poplar Bluff, MO - 0.05" | 0.6" / 0.8"
  • Sikeston, MO - 0.05" | 0.6" / 0.8"
I think it will be possible for a half inch to perhaps a few isolated spots of 2" of snow to fall through mid-morning Wednesday.

As previously mentioned, a Winter Weather Advisory is in effect until noon Wednesday for parts of southeast Missouri, western Tennessee, northeast Arkansas and northern Mississippi.

Winter Weather Advisory

The National Weather Service office in Memphis, TN has issued a Winter Weather Advisory for the Missouri bootheel, northeast Arkansas, western Tennessee and northwest Mississippi. The advisory is in effect until noon Wednesday.

The NWS is calling for up to 1.5" of snow to fall in the areas mentioned above.

As snow moves in from the west later tonight remember that you can check out the latest radar by clicking the "Radar" tab at the top of the page.

Wednesday Snow Part 2

As a follow up to the "Wednesday Snow" post from earlier, I wanted to let you see what another computer model is hinting at for snow.

This is a look at this morning's run of the North American model (NAM) running a snow computation.

You can see that the model is spitting out anywhere from a dusting to 1" of snow in parts of the Missouri bootheel, western Kentucky northeast Arkansas, west Tennessee and northern Mississippi.

Surprisingly, this is pretty close to what I was thinking.

Unlike last week's snow, this one may be able to stick on the ground a little longer. We shall see. Stay tuned...

- Posted from my iPhone

Wednesday Snow

Forecast models are hinting at another snow for parts of the mid-south Wednesday. This could include parts of southeast Missouri, western Kentucky, western Tennessee, northern Mississippi and northern Alabama.

There is still some uncertainty with the snow possibilities. Not all models have converged on the same solution. The other thing, there doesn't appear to be a lot of moisture to work with. However, like last week, it appears there will be enough cold air aloft (and at the surface) to support snow.

Here is a look at NOAA's morning run of the GFS model.

Specifically, this is looking at Wednesday afternoon.

The models shows an upper level low developing over Oklahoma late tonight and closing off by Wednesday morning over Arkansas. The low then pushes east deepening over west Tennessee.

They solid grey coloring indicates some very light moisture to work with. Looking at Murray, Kentucky it is showing only 0.03"- 0.02" of total liquid to work with. That's not a lot. However, if you fluff it up there could be a half inch of snow squeezed out if a snow to water ratio of 20:1 could happen.

I'm not sure if that high of a ratio could happen yet. Temperatures aloft (a few thousand feet) will be cold enough, it will greatly depend on temperatures at the surface.

Again, this is far from a sure bet we will see a measurable snow but it's something to keep an eye on. Stay tuned...

- Posted from my iPhone

Thursday, December 1, 2011

Shot of Cold

If you follow me on Twitter (@johndissauer) you know that I have been talking about a BIG shot of cold air coming down for the Midwest early next week. I've been looking over data trickling in this morning and it still looks to be the case.

Interesting to note that the European computer model and NOAA's Global Forecast model are similar but have subtle differences. Last night's run of the European model is much more aggressive with the cold air intrusion but holds it off for a Wednesday arrival. The later arrival is about a 24 hour delay as to what it has been showing for several days.

NOAA's morning run of the Global Forecast model continues to bring in the cold air starting Tuesday. (Tuesday night is looking cold! Good thing we don't have a snow pack on the ground or it would be really cold.)

I am still waiting for the rest of the morning's GFS to come in so I can take a look further out and I am waiting for the morning run of the European model to come in.

Never the less, I would plan on the coldest air of the season (so far) to arrive Tuesday/Wednesday of next week.


Happy start to Meteorological Winter!

Yes, today marks the beginning of Meteorological Winter. The year breaks down like this...
  • Winter: December 1 - February 28 (or 29)
  • Spring: March 1 - May 31
  • Summer: June 1 - August 31
  • Fall: September 1 - November 30