Winter Weather Advisories & Watches Issued

The National Weather Service in St. Louis has issued a Winter Weather Advisory for parts of eastern Missouri and central Illinois. The Advisory is in effect from 9am Monday -12am Tuesday.

The National Weather Service in Memphis has issued a Winter Storm Watch for the Missouri bootheel, northeast Arkansas and northwest Tennessee. The Watch is in effect Monday afternoon through Monday night.

You can get a closer look at the current watches, warnings and advisories currently in effect by clicking the "Warnings & Watches" link at the top of the page.

10:30am Weather Update

New data coming in this morning and there has been a slight shift to the system for Monday/Tuesday.

The morning run of NOAA's NAM computer model is in and that is what I'll focus on with this post. I also won't go in to too much of the setup as I have already discussed that in previous posts. (Be sure to go back and read the last couple posts if you would like more overall thoughts.)

The NAM has come in more bullish with precipitation amounts BUT the amounts have shifted further north. That means that the band of "heavier" snow has shifted north towards the St. Louis area versus southeast Missouri/southern Illinois.

Let's take a look at some of the snow accumulation maps generated by the NAM. First, a larger view.

(Click the image to see a larger version.)

You can see a definite snow band setting up on the above image. It appears to parallel just north of I-44 through Missouri.

Now a zoom in to the St. Louis area.

(Click the image to see a larger version.)

This puts the heavier band of snow just north and northwest of the St. Louis metro area. It also shows that some of the bigger snow totals could come from central Missouri towards Columbia and Jefferson City. 3"-5" looks like a good call for Columbia.

Now down to the area centered around Paducah, Kentucky.

(Click the image to see a larger version.)

Notice the lack of snow for western Kentucky and southeast Missouri. The model run has warmed things up a little bit more compared to earlier runs. The NAM is hinting at sleet or freezing rain moving through part of the area.

Temperatures are going to be CRITICAL for the above area. Models are still suggesting temperatures will be straddling the freezing mark. This means that a minute shift in fine details could change things from rain, freezing rain, sleet and snow. Based off of this information places like Cape Girardeau see 0.5"-1.5" of snow. However, as I have discussed before, if things shift as little as 30 miles, the numbers could go up or could go down.

Now a look at central Indiana.

(Click the image to see a larger version.)

For the last couple of days models were a little bearish on precip amounts for central Indiana. This morning's NAM has come in a little bit higher with amounts.

You can see how the band of snow moves across central Illinois and through the middle of Indiana. It puts down around 3" of snow for the Indianapolis International Airport (southwest side of city). It is looking like a 1"-3" is a good call for central Indiana. It is also looking like the precipitation will end as sleet.

I'm waiting for the rest of NOAA's global forecast model to come in. Once it is all in and I have a chance to digest some of it, I'll post the information provided by the model.

12:45pm Weather Update

Talking cold, dry and then snow...

Brrr, its cold outside! At 12pm CT, temperatures are sitting in the 20's across Missouri, Illinois and Kentucky. Winds are gusting 25-30mph creating wind chills around 0°.

We can thank this to an arctic air invasion. Along with it being cold, dry air is infiltrating the central United States. Keep the hand lotion and the chapstick handy!

The dry air in place for the weekend is going to factor in to the chances for snow Monday. Moisture is expected to move in to Missouri/Arkansas from the southwest Monday. As the moisture falls from mid-levels, it will encounter the dry air. The drier air will act as a sponge and "soak" up some of the moisture. Don't be surprised to see the radars lighting up by early afternoon in central Missouri but most of the precipitation won't be reaching the ground.

The other thing the dry air will provide is an environment for evaporative cooling. As the moisture falls in to the dry air and evaporates, it cools the air surrounding the moisture droplets. This will help drop temperatures to near freezing (32°F) by Monday evening.

The big question is how much moisture will be left to reach the ground. Overall, models are trending slightly down in the amounts of moisture.

Let's take a look at what some of the models are showing. -- I want to stress that the following images are NOT the forecast, but instead what computer models are showing.

Here is this morning's global forecast model (GFS).

(Click the image to see a larger version.)

Taking a slightly closer look at the Cape Girardeau/Carbondale/Paducah area you can see how it puts a bulls eye over southern Illinois.

(Click the image to see a larger version.)

Now let's take a look at NOAA NAM forecast model from this morning.

(Click the image to see a larger version.)

You can see there are differences between the models. Also interesting to note is the new data from the European forecast agency's computer model and it is showing a little less moisture as does the RPM model.

The way it is looking right now, here's how much snow we could see Monday/Tuesday.

Missouri

• Central Missouri - 3"-5"
• Southeast Missouri - 1"-2.5"
• St. Louis metro - 1.5"-2.5"

Illinois

• Southern Illinois - 1"-2.5"

Indiana

• Indianapolis - 0.5"-2"

Kentucky

• Western Kentucky - 0"-1.5"

As I have said before, things are likely to change between now and Monday morning. The "storm" is still to come out of the Rocky Mountains. Stay tuned...

Morning Valentine's Day Snow Update

New data is coming in from the computer models this morning concerning the possible snow Monday/Tuesday (Feb 13/14) for parts of the Midwest. I've mentioned the NOAA's global forecast model (GFS) and the European forecast agency's model (Euro) in my previous post.

Another model (the NAM) has come in this morning indicating there could be snow falling. Right now the Monday time frame is on the outer edge of the NAM's forecast range but it is indicating moisture and temperatures that would support snow.

There isn't much change this morning amongst the data. The only thing I am seeing is maybe a slight down-tick in the amount of moisture. At this point it still looks like a couple of inches of snow could fall around the St. Louis metro area (maybe 3"-5" towards Columbia), 1"-2" could fall around central Indiana and maybe 1.5"-2.5" in Cape Girardeau. This isn't necessarily my forecast, just numbers coming straight from the models. These are also likely to change over the next 48 hours.

Here is a look at what the GFS is indicating for 48 hour precipitation (liquid equivalent) accumulation ending at 12am CT/1am ET Wednesday.

(Click the image to see a larger version.)

This gives a good indication that there isn't a lot of moisture to talk about. However, it doesn't take much to produce an inch of snow.

The one thing that is consistent is temperatures will be borderline. At the surface all of the models are showing temperatures will 30°-31° for most locations I am looking at (southeast Missouri, southern Illinois, western Kentucky, St. Louis, central Indiana). I say "most" because in western Kentucky surface temperatures are 32°-33° at the surface and 33°-35° at 3,000 feet which could limit snow production. This is going to make it really tricky. A shift in the track by even 30 miles will make a HUGE difference in who gets snow and who gets light rain.

With temperatures so close to the edge between rain and snow I'm looking at snow ratios ranging from 8 to 1 to 12 to 1. 12 to 1 maybe a little optimistic. I used those ratios to determine the snow range listed above.

Stay tuned.

Snow for Valentine's Day?

Yes, it may be possible for parts of the Midwest. I'm talking about snow for Valentine's Day.

Morning computer models are indicating a wave of energy could move east across the Mississippi Valley late February 13 through the early February 14.

It is still very early to be talking about amounts, but it does look like there is a chance southeast Missouri, southern Illinois and western Kentucky could get their first "decent" snow so far this winter.

The European forecast agency's forecast model is suggesting there could be 0.47" of moisture to work with. NOAA's global forecast model is a little more bullish with its amount (0.22"). The big question at this time appears to be temperatures. Surface temperatures are looking to be +/- 1° of 32°. So temperatures are on the fence. As of the way it looks to me right now, I would guess that it would be a very wet snow with perhaps an 8 to 1 ratio (snow to rain). If you do the math that could be a 2"-4" snow.

This is FAR from being set in stone. A change in the weather pattern of 30 miles could make a HUGE difference so don't get too excited just yet. We'll keep an eye on it over the next couple of days.

Stay tuned...

Light Snow Overnight

Light snow will be a possibility overnight for the St. Louis metro area east to central Indiana. Snowfall amounts will be light so no need to get too excited.

A wave of energy is beginning to move out of the Rocky Mountains. This wave will provide the energy needed to produce precipitation.

Temperatures are expected to drop overnight and it appears there will be a 5-6 hour window where temperatures at the surface will be below freezing to allow the snow to reach the ground.

Forecast models are indicating light amounts of moisture with this system. Both the morning runs of NOAA's global forecast model and the European forecast agency model are keeping less than 0.03" of liquid for St. Louis and Indianapolis. Generally speaking, I think we will see a dusting to less than a half inch of snow. (In many cases, it could be less than a quarter of an inch.)

Timing...

• St. Louis metro - Starting around 10:30pm-12:00am. Ending around 6:00am.
• Indianapolis - Starting around 3:30am-5:00am. Ending around 10:00am.

Times listed are for when the brunt of the precipitation will fall. There will likely be some precipitation (rain and/or snow) falling before the times listed above.

Bottom line... Nothing to get concerned about. On my "Freak-Out-Meter" I'd put it at 0.5 out of 10.

Missing: Snow

Be on the lookout for snow. It has been a rarity this winter across the Midwest. Here's an interesting statistic. As of today, Midland, Texas has had more snow than Chicago, the Twin Cities, Boston or New York City.

• Midland, TX: 19.5"
• Twin Cities: 14.9"
• Chicago: 13.9"
• Boston: 7.8"
• New York City: 7.2"

So where is all the snow? I can tell you where it isn't. It isn't over the United States (lower 48 states).

Below is a map from NOAA indicating snow depth as of this morning. Notice the lack of snow, even over the northern plains.

(Click the image for a larger version.)

As of this morning only 26.2% of the United States is covered by snow. This is the lowest amount of snow coverage for this day since 2005.

• 2012 - 26.2%
• 2011 - 48.3%
• 2010 - 59.9%
• 2009 - 35.5%
• 2008 - 50.8%
• 2007 - 41.4%
• 2006 - 27.3%
• 2005 - 23.6%

Quickly looking over weather data from this morning I am not seeing any big signs of snow coming our way in the next week. Perhaps something around February 17, but don't get too excited yet. The models have consistently shown storms capable of producing a good snow 264 hours out almost on every run of the computer models. None of them have happened. Waa waa waa...

Where's the Cold?

That's the question I have been getting a lot lately. I have got an answer if you've been asking the same question. The cold air has been stuck up in Alaska.

Check out the information the National Weather Service in Fairbanks, Alaska put out.

"January 2012 was the coldest month in more than 40 years in Fairbanks. Not since January 1971 has the Fairbanks area endured a month as cold as this." This was also the 5th coldest January on record. (The coldest January on record was 1971 when the temperature was 31.7° below average per day.) Fairbanks finished January 2012 at 19° below average per day. Nome, Alaska was 21° below average per day.

Diving a little deeper in to the numbers... At the Fairbanks Airport, the average high temperature for January -18.2°. The average low temperature was -35°.

I haven't had too many complaints about not having the barbaric temperatures but it needs to feel like winter... Right?! The start of 2012 has been crazy warm across the Midwest. Here's a look at how temperatures fared compared to normal for January 2012.

Illinois:

• Carbondale +4.9°
• Chicago 6.4°
• Moline +6.3°

Indiana:

• Bloomington +4.7°
• Evansville +4.9°
• Indianapolis +5.6°
• Lafayette +5.4°
• Muncie +4.3°
• Kentucky:
• Paducah +5.5°

Missouri:

• Cape Girardeau +6.1°
• Chesterfield +5.1°
• Columbia +5.7°
• Poplar Bluff +5.9°
• St. Charles +4.7°
• St. Louis +6.3°

Looking at long term doesn't show any near-term changes. It appears that through the middle of February all of the cold air will stay bottled up over Alaska and Canada and the lower 48 should remain relatively warm. Having said that, we will still see shots of cooler air coming down, but it should only be short lived.