Exclusive: Hans Güttenhoffer Interview

I was able to score an exclusive interview with Hans Güttenhoffer for the 10pm newscast Christmas Eve.  Who is Hans you ask?  Hans is the meteorologist for the North Pole.  He has been forecasting exclusively for Santa Claus for 423 years.  The man has seen it all!  You know if a forecaster can keep their job for that long he has to be good.

It turns out Hans has a little bit of a hearing problem (think of the wax build up after all those years) but it was good talking with him during the newscast.
I've known Hans for several years.  He's the one that helps me get a GPS fix on Santa's sleigh late Christmas Eve.  We were on several conference calls over the last few days discussing what weather conditions would be like for Santa's big flight.

2:10pm CT Weather Update - Fast Moving Storm

Just a quick post to make a few slight tweaks to my snow forecast.  The storm is coming in as expected.  Rain has broken out across Missouri and Illinois.

Radar image from 2:04pm CT.
(Click the image to see larger version.)

Mixed in with the rain there are a few pockets of sleet.  As cold air drops south later this afternoon, rain will change over to snow.  In fact, if you look closely at the image above, you can see the changeover occurring over extreme southeast Iowa/western Illinois.

For timing on the snow, check back to my blog post from yesterday.

SNOW FORECAST:

Indiana:

• Columbus: 2"-4"
• Indianapolis: 3"-5"

Illinois:

• Mt. Vernon: 2"-4"

Missouri:

• Cape Girardeau: Up to 1"
• Farmington: 2"-5"
• Kansas City: 1"-3"
• Perryville: 2"-5"
• St. Louis: 2"-4"

FREAK-OUT-METER:

Indiana:

• Columbus: 3
• Indianapolis: 4

Illinois:

• Mt. Vernon: 3

Missouri:

• Cape Girardeau: 1
• Farmington: 3
• Kansas City: 2
• Perryville: 3
• St. Louis: 3

Fast Moving System

A quick moving system will be passing through the Midwest Friday and Saturday.  Computer models are still a little spread regarding how much snow and where.

National Weather Service offices have issued Winter Storm Watches and Winter Weather Advisories for parts of Kansas, Missouri, Illinois and Indiana.

Watch, Warning & Advisory - 3:49pm CT

Let me show you a couple computer model suggested snowfall totals and then I'll tell you how much I'm currently thinking.

European forecast agency's computer model.

ECMWF Snow Accumulation through 12pm CT Saturday.
(Click image to see larger version.)

ECMWF Snow Accumulation through 12pm CT Saturday.
(Click image to see larger version.)

ECMWF Snow Accumulation through 12pm CT Saturday.
(Click image to see larger version.)

National Weather Service's global forecast model.

GFS Snow Accumulation through 12pm CT Saturday.
(Click image to see larger version.)

NAM computer model:

NAM Snow Accumulation through 9pm CT Saturday.
(Click image to see larger version.)

NAM Snow Accumulation through 12pm CT Saturday.
(Click image to see larger version.)

NAM Snow Accumulation through 9pm CT Saturday.
(Click image to see larger version.)

It is interesting to note that all three of the above models try to move snow around the St. Louis metro area.

WHAT I'M THINKING:

The system will start to spread moisture north starting Friday afternoon.  I think most of the snow will come down as a wet, slushy snow.  The slushy snow will have a big impact on snow accumulation.  If temperatures end up being 2° to 3° colder than computer models are projecting, we could easily add another 1"-3" on to the totals shown below.

It should come to an end from early Saturday morning in Kansas City, late morning in St. Louis and Saturday afternoon in central Indiana.

Indiana:

• Columbus: 2"-3" (Up to 4" not out of the question.)
• Indianapolis: 3"-5"

Illinois:

• Mt. Vernon: 2"-4"

Missouri:

• Cape Girardeau: Up to 2" (Probably not much accumulation.)
• Farmington: 3"-6"
• Kansas City: 1"-4"
• Perryville: 3"-5"
• St. Louis: 2"-3" (A few locations up to 4")

FREAK-OUT-METER:

Indiana:

• Columbus: 3
• Indianapolis: 3

Illinois:

• Mt. Vernon: 4

Missouri:

• Cape Girardeau: 2
• Farmington: 4
• Kansas City: 3
• Perryville: 4
• St. Louis: 3

International Space Station Viewing Opportunity

International Space Station sighting
information for southern Colorado.

There's an opportunity to see the International Space Station fly overhead later today.  Here are times to look, along with duration and direction the ISS starts/exits.

• Cape Girardeau: 5:22pm CT - 4 minutes - SW/NE
• Colorado Springs: 5:57pm CT - 5 minutes - WSW/NNE
• Columbus, IN: 6:23pm ET - 4 minutes - SW/NE
• Indianapolis: 6:23pm ET - 3 minutes - SW/ENE
• Pueblo: 5:57pm CT - 5 minutes - WSW/NNE
• St. Louis: 5:22pm CT - 5 minutes - SSW/ENE

If you live near one of these locations, assume the time/direction are close.

Dreaming of a White Christmas

Are you dreaming of a White Christmas?  For many parts of the country you may be in luck.

Keep in mind, Christmas is still a loooooong way away.  Climatologically speaking, the chances for a White Christmas are not great.  Here are the historical probabilities of a white Christmas for the lower 48.

(Click the image to see larger version.)

As you can see from the map above, the Midwest generally has a less than 10% probability to as much as a 40% probability of a White Christmas.  A White Christmas is defined as 1" or more of snow on the ground as of 7am (local time) Christmas morning.

The probability is close to the same for southern/southeastern Colorado.  Approximately a 10% to 25% probability.

December 25 is now beginning to come in view for one of the computer models we use to forecast.  With Christmas currently at the far edge of the model's view, you must take what it is projecting with a GIGANTIC grain of salt.

The model I am referring to is the National Weather Service's Global Forecast model, the GFS.

Looking at the data, the model is suggesting much colder weather for much of the country.  This far out I am sure the model is exaggerating how cold the air actually will be, but it is something to take note of.

Here is a look at temperatures at 850mb, or around 5,000' at 6pm CT December 24.


The GFS definitely plunges cold air out of Canada and dives it far south.  It would suggest temperatures in the 20°s and 30°s for Missouri and Iowa.

We all know that ahead of a big plunge in temperatures there is usually a storm.  The GFS doesn't disappoint.  It develops a storm over the NW United States, dives it in to the Rockies, moves it through the Midwest and then has it exiting the NE United States.

Here is a view of different time periods leading up to Christmas from the GFS.

6pm CT Monday, December 23
(Click the image to see larger version.)

According to the model, a system has passed through southern Colorado, New Mexico and the Texas panhandle.  Behind the cold front, cold air is spilling down the Rocky Mountains.  The model also develops light moisture, which if this model is to pan out, would be snow falling over eastern/southern Colorado, central/eastern New Mexico and Kansas.

6am CT Tuesday, December 24
(Click the image to see larger version.)

By the morning of December 24 the area of low pressure is developing as it moves up through the Ohio River Valley.  Thunderstorms could be developing ahead and along the cold front.  Behind the cold front, moisture is running in to cold air and snow breaks out over Illinois, Missouri, Arkansas and northwest Indiana.

6pm CT Tuesday, December 24
(Click the image to see larger version.)

By late afternoon/evening of Christmas Eve the system is moving up the east coast taking the moisture with it.  Before it leaves, it continues to drop moisture, in the form of snow, over Illinois, Indiana, Michigan and Ohio.  Behind the system, cold air continues to spill in to the Midwest.

That is a quick little play-by-play of what the computer model is suggesting.  Again, this will LIKELY change about 400 times between now and Christmas.

At the beginning of the month I had posted that an experimental loooooong range computer model was suggesting Christmas could be warm for much of the country.  The latest run of that model, the European forecast agency's model, is now suggesting cooler weather, and in some cases near normal temperatures for Christmas.

At this point this is more for fun than anything else.  I don't know about you, but I find it fun to look ahead and see what could happen.  Don't take the information above seriously as it will likely change.

I'll keep an eye on what the models suggest as we get closer to Christmas.  When I'm putting my daily forecast together I will often tweet little bits of information as I see it, so be sure to follow me on Twitter (@johndissauer).  I'm sure I'll have updates here on the blog as we get closer as well.

Bottom line... Should you take what the computer model is suggesting with any seriousness?  No.  If you are hoping for a White Christmas, it gives you a little bit of hope.  Keep hoping!  But at this point I wouldn't be making any decisions based on the data presented.  I know I'm not.

Freak-Out-Meter: 0 out of 10

Who Ordered the Snow?

There have been a couple weather systems pass through the country leaving snow behind this past week.  It is interesting to look at the national snow analysis done by the National Operational Hydrologic Remote Sensing Center.

For December 9, 2013 sixty-seven percent of the United States (lower 48) was covered by snow.

Snow Depth - December 9, 2013
(Click image to see larger version.)

In contrast, December 9, 2012 only 26% percent of the country was covered by snow.

Snow Depth - December 9, 2012
(Click image to see larger version.)

The National Weather Service started keeping track of the national snow cover in 2003, so stats only go back that far.  When I look specifically at December 9 over the past 11 years, the national average is 40%.  This makes 2013 a 68% increase over the 11-year average and also makes December 9, 2013 the "snowiest" December 9 in the past 11 years.

Late Night Winter Storm Update

A really quick update to show you what the European forecast agency's computer model is projecting.  Also, after looking at all of the evening computer model data I'm leaving most of my snow forecast alone.  There are a few teaks but they are minor.



Here is a look at snowfall accumulations through 6pm CT Friday from the European computer model.

0z ECMWF - Snow accumulation through 7pm ET Friday.

(Click the image to see larger version.)

0z ECMWF - Snow accumulation through 6pm CT Friday.

(Click the image to see larger version.)

0z ECMWF - Snow accumulation through 6pm CT Friday.

(Click the image to see larger version.)

SNOW FORECAST

Snow accumulation through Friday evening.



ILLINOIS:

• Marion: 8"-12"


• Mt. Vernon: 9"-14"

INDIANA:

• Bloomington: 6"-11"


• Columbus: 7"-12"


• Indianapolis: 5"-8"

KENTUCKY:

• Paducah: 1"-3"

MISSOURI:

• Cape Girardeau: 5"-9"


• Farmington: 8"-13"


• Perryville: 7"-11"


• Poplar Bluff: 4"-7"


• St. Louis: 2"-4"

Also don't forget about the ice threat, especially in the Missouri bootheel and western Kentucky.  I have a feeling there will be power outage numbers will be increasing through the overnight hours.  Keep your phones, laptops and tablets charged in case the power does go out.



FREAK-OUT-METER



ILLINOIS:

• Marion: 7


• Mt. Vernon: 7

INDIANA:

• Bloomington: 7


• Columbus: 7


• Indianapolis: 6

KENTUCKY:

• Paducah: 8

MISSOURI:

• Cape Girardeau: 6


• Farmington: 7


• New Madrid: 8


• Perryville: 7


• Poplar Bluff: 6


• St. Louis: 4

Changing to Snow; Thursday Evening Update

There is still sleet and freezing rain falling across parts of the Midwest but much of the sleet is now changing over to snow.  Reports of 3" to 4" of snow already coming in across parts of the leadbelt of southeast Missouri. (Just now a report of 4.5" of snow in St. Francois County, Missouri.)  In some situations the snow has changed over sooner than forecast projected.

Some of the new evening computer model data is coming in.  Here are a couple views of what the computer models are projecting for snowfall totals through the time on the graphic.  You will notice a discrepancy between the models.  (Welcome to the world of a meteorologist.)

0z RPM Snowfall Accumulation:

(Click image to see larger version.)

(Click image to see larger version.)

0z NAM Snowfall Accumulation:

(Click image to see larger version.)

(Click image to see larger version.)

I'm going to keep the forecast relatively unchanged (a few minor tweaks).

SNOW FORECAST
Snow accumulation through Friday evening.

ILLINOIS:

• Marion: 8"-12"

INDIANA:

• Bloomington: 7"-12"
• Columbus: 7"-12"
• Indianapolis: 5"-7"

KENTUCKY:

• Paducah: 2"-4"

MISSOURI:

• Cape Girardeau: 5"-9"
• Farmington: 8"-13"
• Perryville: 7"-11"
• Poplar Bluff: 4"-7"
• St. Louis: 2"-4"

FREAK-OUT-METER

ILLINOIS:

• Marion: 7 

INDIANA:

• Bloomington: 7
• Columbus: 7
• Indianapolis: 6

KENTUCKY:

• Paducah: 8

MISSOURI:

• Cape Girardeau: 6
• Farmington: 7
• New Madrid: 8
• Perryville: 7
• Poplar Bluff: 6
• St. Louis: 4

Major Winter Storm Taking Shape

A major winter storm for the Midwest is in the process of getting underway.

A strong cold front has ushered through Missouri, Illinois, Indiana and Kentucky.  Temperatures in the 60°s and 70°s yesterday will be replaced by falling temperatures through the day to the upper 20°s and lower 30°s.

Moisture is already starting to fall across Missouri and Illinois.  A friend in Cape Girardeau told me it has already started to sleet as of 12:30pm CT and there are multiple reports of sleet around the St. Louis metro area.

Moisture and cold temperatures are the big headache for forecasters around the region.  We know there will be moisture, but how much?  We also know there will be cold air, but how much cold air will there be and where will it be above the surface?  The answers to those questions will determine how much and what kind of precipitation will be seen.

There are many facets to the next 24 to 36 hours.  The first round, starting now, is going to produce rain, freezing rain and sleet.  This will continue through the evening.  I think much of it will fall in the form of sleet, especially north of a Poplar Bluff -- Cape Girardeau -- Evansville, IN line.

Freezing rain will end up being a significant problem for areas south of that line including the Missouri bootheel, western Kentucky, northeast Arkansas and northwest Tennessee.  The freezing rain should start later this afternoon (once the temperature reaches 32° and below) and continue for some areas through Friday morning.  I think it is totally possible for some areas, especially in western Kentucky and Pemiscot/Dunklin counties in Missouri to see 0.5" to 0.75" of ice and I wouldn't be surprised if a few locations go higher.

Here is a look at a meteogram for Paducah, Kentucky looking specifically at freezing rain accumulation.

Paducah, Kentucky Meteogram
(Click to see larger version.)

Each line represents a separate computer model run indicating what it projects for freezing rain/ice accumulation.

While not the 2009 Ice Storm, this much ice will NOT be fun.  Make sure you have leave your cell phones, laptops and tablets charged in case power does go out.  I suspect there will be power outages from northeast Arkansas through the bootheel in to western Kentucky.

Further north sleet will be the issue this afternoon.  Sleet will fall from Missouri to Indiana during the afternoon and evening.  Here is a look at the meteogram for Cape Girardeau looking at sleet accumulation.

Cape Girardeau Meteogram
(Click the image to see larger version.)

Again, each line represents a different computer model run.

Sleet is not as bad as freezing rain, but still not fun to drive on.

Sleet is always a killer to snow forecasts but I think in this situation it may not hurt the snow forecast too much.  The reason being this is going to come through in two waves.  First is sleet/freezing rain and then it will be snow.

The models this morning are narrowing in on the target for the heaviest snow.  I think the target has shifted slightly north of what they were showing before.  Now the heaviest band of snow could go through Farmington, Missouri through southern Illinois in to south-central Indiana.

Here is a look at how much moisture will be available for snow production from various computer models.

(Click image to see larger version.)

(Click image to see larger version.)

In some cases the models have up'ed the moisture and in other cases they have dropped.  Bottom line, I do think there is going to be some pretty good snow overnight through Friday late afternoon.

Here is a closer look at how much snow accumulation the European forecast agency's computer model is projecting through 7pm ET Friday.

12z ECMWF - Snow accumulation through 6pm CT.
(Click image to see larger version.)

12z ECMWF - Snow accumulation through 6pm CT.
(Click image to see larger version.)

12z ECMWF - Snow accumulation through 7pm ET.
(Click image to see larger version.)

My forecast is going to stay pretty close to what it was before.

SNOW FORECAST
Snow accumulation through Friday evening.

ILLINOIS:

• Marion: 8"-12"

INDIANA:

• Bloomington: 7"-11"
• Columbus: 7"-12"
• Indianapolis: 4"-6"

KENTUCKY:

• Paducah: 1"-2"

MISSOURI:

• Cape Girardeau: 5"-9"
• Farmington: 7"-12"
• Perryville: 7"-10"
• Poplar Bluff: 4"-6"
• St. Louis: 2"-4"

FREAK-OUT-METER

ILLINOIS:

• Marion: 6 

INDIANA:

• Bloomington: 7
• Columbus: 7
• Indianapolis: 5

KENTUCKY:

• Paducah: 8

MISSOURI:

• Cape Girardeau: 6
• Farmington: 6
• New Madrid: 8
• Perryville: 6
• Poplar Bluff: 6
• St. Louis: 4

How much do you think will fall at your location?

As always, you can get more information by following my Twitter account, @johndissauer.

Wednesday Night Update: Snow & Ice on Track

Some of the data tonight is suggesting the storm for Thursday and Friday may track slightly south of what the models had suggested before.  Both the NAM and the RPM computer models are hinting at that.  I haven't completely bought in to that just yet.  I want to see what some of the other models decide to do tonight.

The slight jog to the south greatly affects numbers for both snow and sleet/snow accumulation.  That is why you often hear meteorologists say "If the storm moves 50 miles one way or the other it can make a difference."

Here is what the evening run of the RPM (0z) computer is suggesting for ice/sleet accumulation and snow accumulation.  As of now I am not tweaking my numbers just yet.  However, don't be surprised to see the numbers change tomorrow as more data becomes available.

RPM Ice/Sleet Accumulation:

0z RPM Ice Accumulation through Friday afternoon.
(Click the image to see larger version.)

RPM Snow Accumulation:

0z RPM Snow Accumulation through Friday afternoon.
(Click the image to see larger version.)

0z RPM Snow Accumulation through Friday afternoon.
(Click the image to see larger version.)

This will be my last update for tonight.  I'll look at the data in the morning and hopefully have something posted by early afternoon.

Ice & Snow Projections: Wednesday Evening Update

A quick update to let you see what the latest 12km RPM computer model is projecting for freezing rain/sleet and snow accumulations for parts of Missouri, Illinois, Kentucky, Tennessee, Arkansas and Indiana.

This is the afternoon RPM's projection of ice accumulation.

18z RPM Ice Accumulation
(Click image to see larger version.)

This is the afternoon RPM's projection of snow accumulation.

18z RPM Snow Accumulation
(Click image to see larger version.)

Finally, here is the model's snow projection for central/southern Indiana.

18z RPM Snow Accumulation
(Click image to see larger version.)

I suspect we will see these numbers bouncing around over the next 12-18 hours while the models try to fine tune their numbers.  I suspect we will see the numbers going up a bit more for southern/central Indiana.  To see my latest snowfall projections, check out my blog post from earlier today.

Significant Snow & Ice

Looking over the morning weather data and one word keeps coming out of my mouth.  "Wow!"  Computer models are narrowing in on a target for winter weather Thursday through Friday for southeast Missouri, southern Illinois, western Kentucky and central/southern Indiana.

Let me start by saying there are many facets to this storm.  There will be rain changing over to sleet/freezing rain and then changing over to snow.  Travel could be a MAJOR headache for week's end.

The critical part of the forecast is trying to determine when things change over.  There is going to be PLENTY of moisture to work with.  In fact, the morning computer model runs are very aggressive with the moisture.

Here is a look at the profile for Cape Girardeau from this morning's run of the NAM computer model.

12z NAM for Cape Girardeau
(Click the image to see larger version.)

Green = rain | Orange = sleet | Red = freezing rain | Blue = snow

As you can see from the model, a little bit of everything is showing up.  It does appear that this is going to start out for rain in most locations.  As the colder air arrives at the surface the change will begin to happen.  As the layer of cold air at the surface is shallower, freezing rain will be the concern.  As the layer "thickens" it will eventually change over to sleet.  Once the column is large enough with cold air, it will change over to all snow.  Often times this happens at the tail end of the moisture, but that doesn't appear to be the case this time.

Ice is going to be a concern for several areas.  For places like Cape Girardeau and Poplar Bluff there could be 0.25" of ice before changing over to snow.  In Paducah, 0.5"-0.75" of ice accumulation before changing over to snow isn't out of the question.  Right now, Columbus, Indiana and Bloomington, Indiana look to stay away from any ice.  I do think there will be quite a bit of sleet contamination, which will cut down on the freezing rain accumulation, for areas north of a line from Poplar Bluff to Cairo, IL to Owensboro, KY.

Here is a look at how much freezing rain and sleet accumulation the NAM and the GFS are suggesting.

12z NAM Sleet Accumulation through 6pm CT Friday.
(Click image to see larger version.)

12z GFS Sleet Accumulation through 6pm CT Saturday.
(Click image to see larger version.)

12z NAM Freezing Rain Accumulation through 6pm CT Friday.
(Click image to see larger version.)

12z GFS Freezing Rain Accumulation through 6pm CT Saturday.
(Click image to see larger version.)

As you can see, the models are much more bullish on sleet than freezing rain.  However, even a tiny bit of ice can cause HUGE problems.

Let's take a look at how much moisture will be available during the time the computer models suggest it will be all snow falling.  To be honest, I was a little surprised to see the consistency and the amount across the board.

Here is a matrix of quantitative precipitation forecasts (QPF) for various locations in Missouri, Illinois, Kentucky and Indiana.

Through Friday Afternoon

Through Friday AFternoon

The amounts shown above indicate how much moisture will be available while the atmospheric column is supportive of snow generation.  Yeah, there's a LOT!

Simple snow formulas suggest a 10:1 ratio.  It doesn't look SUPER cold in any of the locations (St. Louis will be a little colder) so I don't think this cause the ratio to slide too much.

Here's another look at some of the data from the computer models.  This is looking at snow accumulation from both this morning's run of the GFS and the NAM.

12z NAM Snow Accumulation through 6pm CT Saturday.
(Click image to see larger version.)

12z GFS Snow Accumulation through 6pm CT Saturday.
(Click image to see larger version.)

As to how much snow I think could fall?

INDIANA:

• Bloomington: 7"-10"
• Columbus: 8"-12"
• Evansville: 9"-14"
• Indianapolis: 4"-6"

ILLINOIS:

• Marion: 8"-13"

KENTUCKY:

• Paducah: 5"-8"

MISSOURI:

• Cape Girardeau: 7"-12"
• Poplar Bluff: 6"-10"
• St. Louis: 1"-2" (maybe 3)

Hope you have the snow shovels ready!  But PLEASE be careful if you are in places that could get ice first.  If you go out to shovel and hit some of the ice, your day may not be overly joyful.

Bottom line...

• There will be rain, freezing rain, sleet and snow.
• This will NOT be a repeat of 2009's historic ice storm.
• Temperatures get much colder.
• Significant snow will fall over parts of the Ohio/Mississippi River valleys.
• There could be another round of snow coming through Sunday/Monday. Let's first get past Thursday and Friday before dealing with Sunday/Monday.

FREAK-OUT-METER: (Scale of 0 to 10)
Time to break down the Freak-Out-Meter a little more.  If you've been paying attention to it over the last couple days, it is has been slowly inching up.

INDIANA:

• Columbus/Bloomington: 6/7
• Evansville: 7
• Indianapolis: 5

ILLINOIS:

• Marion: 6

KENTUCKY:

• Paducah: 7 (because of freezing rain)

MISSOURI:

• Bootheel: 7 (because of freezing rain)
• Cape Girardeau: 6
• Poplar Bluff: 6
• St. Louis: 3

Reminder:  To get more weather information throughout the day and night, follow me on Twitter (@johndissauer) where I put out lots of information and thoughts that don't necessarily make it in to my blog.

Colorado Deep Freeze

It is going to get cold.  Let me rephrase that, it is going to get VERY cold in southern and eastern Colorado starting in less than 24 hours.

As of last night's forecast, temperatures were forecast to stay at or below freezing Wednesday through late Monday morning for Colorado Springs and Pueblo.  New data this morning is suggesting temperatures could stay at or below freezing all the way through December 18.  Brrr!

The prolonged period of temperatures at or below freezing got me wondering how common is prolonged periods of cold temperatures for Colorado Springs and Pueblo.  Just looking back over the last five years of data for Colorado Springs shows that only six times has the temperature stayed at or below freezing for four consecutive days or more.

With the help of some of the meteorologists at the National Weather Service office in Pueblo I was able to get historical perspective.  Below are the records and Top 5 number of days below freezing (31° or less).

COLORADO SPRINGS:

1. 14 days ending January 9, 1970
2. 13 days ending January 10, 1979
3. 13 days ending January 11, 1973
4. 12 days ending March 4, 1960
5. 9 days ending February 7, 1985

PUEBLO:

1. 13 days ending January 11, 1974
2. 11 days ending March 3, 1960
3. 10 days ending January 9, 1988
4. 10 days ending January 9, 1979
5. 9 days ending December 25, 1983

Special thanks to the National Weather Service Pueblo office for helping dig up the stats.

Slip Slidin' - Tuesday Morning Update

Not a lot of time this morning to update the blog but I did get a few minutes to look over some of the new data trickling in from the morning computer model runs.

First take-away... The models are a little further north with the track of the system.  Which was expected.

There is a lot yet to be determined on placement/precipitation type.  As usual, the National Weather Service's NAM computer model is a little hyperactive with the amounts of precipitation.

Let me run you through several maps that can give you an idea of where the models are placing different types of precipitation.  Before I say anything else, PLEASE remember that this is not locked in stone.  These are just computer model projections and far from the actual forecast.

First, here is the NAM's projection of snow accumulation through 6pm CT Friday.

12z NAM - Snow Accumulation through 6pm CT Friday
(Click image to see larger version.)

 Now here is the NAM's projection of sleet accumulation through 6pm CT Friday.

12z NAM - Sleet Accumulation through 6pm CT Friday
(Click image to see larger version.)

Now the dread "ice" word.  Freezing rain accumulation through 6pm CT Friday.

12z NAM - Freezing Rain Accumulation through 6pm CT Friday
(Click image to see larger version.)

As you can see, the NAM is perhaps a little overzealous, especially with snow in the St. Louis metro.  (12"+?!?!)  The model is also heavy handed with the sleet for southeast Missouri and southern Illinois.  I could buy this scenario.

This event is at the edge of the model's projection view.  I have a feeling we will see these numbers dropping over the next 24-36 hours.

Now a look at the National Weather Service's Global Forecast model, the GFS.

Here is a look at what this morning's run of the GFS is suggesting for snowfall accumulation through 6pm CT Friday.

12z GFS - Snow Accumulation through 6pm CT Friday
(Click image to see larger version.)

 GFS sleet accumulation through 6pm CT Friday.

12z GFS - Sleet Accumulation through 6pm CT Friday
(Click image to see larger version.)

Finally, the GFS suggestion for freezing rain (ice) accumulation through 6pm CT Friday.

12z GFS - Freezing Rain Accumulation through 6pm CT Friday
(Click image to see larger version.)

Observation of the GFS... First, it is further south than the NAM.  It is also not as bullish with snow.  The GFS tries to hit the sleet and freezing rain a little harder.

Again, the models should start to line up better as we get closer to the event.

Bottom line... Cold air is expected to arrive later this week.  Moisture will be in place and there could be a mix of rain, freezing rain, sleet and snow across parts of southeastern/eastern Missouri, southern Illinois, western/northern Kentucky, northern Arkansas, northwest Tennessee and central/southern Indiana.  If you have travel plans Thursday-Saturday pay close attention to the forecast.

Reminder:  Follow me on Twitter for more information as it becomes available.  @johndissauer

Freak-Out-Meter:  4 out of 10