Wednesday Morning Update

The next round of computer model data is coming in this morning and the models are keeping the upward trend. Last night I mentioned it would be interesting to see how this morning’s runs handle the moisture. Do they take it up, keep it the same or drop it?
I look at several computer forecast models when putting together the forecast. During snow storms I’ll look at upwards of eight different models from various worldwide forecast agencies. So far this morning, NOAA’s global forecast model (GFS) is in along with the RPM.

Let’s take a look at the breakdown of how much water the models are suggesting will be available for snow production.

CITY: GFS H2O | CHANGE FROM 0z RUN

• Cape Girardeau: 0.10” | +0.03”
• Indianapolis: 0.22” | +0.06”
• St. Louis: 0.16” | +0.03”

Looking at the change from last night it may not look like a big change. However, when forecasting snow, it doesn’t take much to make more snow. For Cape Girardeau and St. Louis the 0.03” difference could add an additional half inch and for Indianapolis the additional 0.06” could add an additional inch of snow.

With the amount of cold air coming in with the cold front, I am looking for snow to rain ratios of 14 to 1 or as high as 17 to 1. Going strictly from the GFS model that would put down:

• Cape Girardeau: ¾” to 1.5” of snow
• Indianapolis: 3”-4” of snow
• St. Louis: 2”-3” of snow

I am still waiting to see what the European forecast agency’s computer model comes up with. All I have to look at right now are the numbers from last night’s run. They are fairly comparable to this morning’s GFS. Cape Girardeau – 0.09” | Indianapolis – 0.19” | St. Louis – 0.19”. Numbers from this morning’s European model will be in later this afternoon and I’ll try to give an update when they come out.

Timing: The snow should begin to fall in St. Louis during the pre-dawn hours (2am-4am CT), in Cape Girardeau during pre-dawn hours (5am-7am CT) and in Indianapolis by early afternoon (12pm-3pm ET).

As for my “Freak-Out-Meter”… I am going to keep it at a 3 out of 10 for St. Louis and Cape Girardeau and move it to a 4 out of 10 for Indianapolis. The “Freak-Out-Meter” is hard to score because there are two ways to do it. I could score it on how people’s reaction will be or how the reaction should be. I try to score it to how people’s reaction should be.

Remember you can follow me for more timely updates via Twitter @johndissauer and via my Facebook page.

-Posted from my iPhone

Numbers Going Up?

New data is streaming in as I type tonight. Interesting to note that on first look, it appears NOAA's global forecast model is coming in slightly wetter.

The time frame I am talking about is still Thursday in to Friday morning for parts of the Midwest.

A strong surge of cold air will blow in behind a cold front passing the Midwest Wednesday evening and Thursday morning. Th cold air will work very efficiently at changing the moisture to snow.

Earlier today I showed you what the GFS computer model was suggesting for moisture in Cape Girardeau (0.02"), Indianapolis (0.15") and St. Louis (0.07"). As of the time I am writing this, data is only available through Friday evening.

Here's a look at what the new run of the GFS is showing. Again, this is how much moisture is available, not snow.

• Cape Girardeau - 0.07"
• Indianapolis - 0.16"
• St. Louis - 0.13"

Comparing that to this morning's numbers you can see the model is starting to increase the amounts.

The strength of the cold air is impressive. I think this could generate a 14:1 to 16:1 snow with a few locations seeing higher ratios. This would equate to around 1" in Cape Girardeau, 1.5" to 2.5" in Indianapolis and 1" to 2.5" in St. Louis. There could be a few locations upwards of 3" around central Indiana (likely north of Indianapolis).

It will be interesting to see what Wednesday morning's computer models are showing to see if they continue the trend of increasing the moisture, keeping it the same as tonight's runs or decreasing the moisture.

I am going to slightly increase the "Freak-Out-Meter" to a 3 out of 10. It won't be bad, but for some, this will be the first measurable snow of the season.

Stay tuned...

Light Snow Possible by Week's End

It is starting to look like we could see a little snow across parts of Missouri and Illinois within the next 72 hours. At this point, I want to stress the word “little”. I’m not talking about a major snowstorm. In fact, I’m not sure if the word “snow” or “storm” should even be included in this discussion.

A strong cold front is just beginning to move across the Canadian/United States border. Behind the front, cold air is on the march. At 1pm CT, temperatures were in the single digits in Alberta and British Columbia.


Forecast models are indicating the cold front will pass through Missouri and Illinois late Wednesday night into early Thursday morning. Behind the cold front, the previously mentioned cold air in Canada will spread over the Midwest.

It appears that the strength of the cold air will work on the little amount of moisture in the air and squeeze out a few snow showers Thursday. Both the European Agency’s forecast model and NOAA’s forecast model are suggesting light amounts of precipitation for the cold air to work with. What is “light amounts”? Let’s take a look.

Here is a breakdown of how much liquid water is forecast to fall by the models.

CITY: EURO | GFS

• Cape Girardeau: 0.05” | 0.02”
• Indianapolis: 0.15” | 0.12”
• St. Louis: 0.06” | 0.07”

You can see what I mean by small amounts of liquid to work with. Typically, you can say there is a 10:1 ratio of snow to water. In this case, with the surge of cold air, I think we could see at most a 14:1 ratio. This would mean approximately a dusting to a half inch in Cape Girardeau, a half inch to 1” in St. Louis and 1” to 2” in Indianapolis.

Here is another view of what some of the models are indicating for Cape Girardeau and Chesterfield, Missouri.

Cape Girardeau:

Chesterfield:

The above are called meteograms. The ones I have posted indicate how much snow will fall according to various runs of forecast models and the forecast from the National Weather Service. Remember, a forecast model is just that… A model. It isn’t reality.

Bottom line… Could there be some snow? Yes. Will it be a lot? No. Where do I have my “Freak-Out-Meter”? I’ve currently got it at 2 out of 10.

- Posted from my iPhone

Website Update

Made a small update to the design of the website today. I have added a recent satellite image from the University of Wisconsin and the latest forecast map for today from NOAA's Hydrometeorological Prediction Center (HPC).



You can view the images by scrolling down the site and looking in the right hand column.

Merry Christmas

Merry Christmas!


- Posted from my iPhone

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.

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.

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