3:00pm Weather Update - Closer Look at Snow

In my previous post I talked a lot about the Wednesday night through Thursday storm that will be affecting the Midwest.  The new morning computer model runs are in and I thought we’d take a little closer look at the snow potential from the storm.

I am still not convinced this is going to produce much snow for St. Louis and Indianapolis (and further south).  In fact, I am not sure we will get more than a few snowflakes in the St. Louis metro, although the further north from St. Louis the better chance more snow will fall.  With Indianapolis there could be a little more.

First, here is the snow output from NOAA’s North American Mesoscale Model, the NAM.  This shows snowfall through 84 hours, or 6pm CT Friday.

(Click the image to see larger version.)

Second, here is the snow output from NOAA's global forecast model, the GFS.  This shows snowfall through 120 hours, or 6am CT Saturday.

(Click to see a larger image.)

It should look obvious that one model is higher resolution (NAM) over the other (GFS).   The NAM tries to put more details in the image.

The take-aways for me is the both models keep the bulk of the snow over the northern half of Indiana and the GFS is a little more bullish with snow totals.

Generally speaking, it has 0"-2" of snow across central Indiana.  Let’s take a look at specifically what each model is suggesting.

MODEL	SUGGESTED SNOWFALL
RPM	0.3”
NAM	0.6”
GFS	1.4”
Euro	1.5”

The NAM and RPM models are higher resolution.  The RPM looks out through only through 6am CT Friday.  The NAM starts the changeover from rain to all snow by evening Thursday.  The GFS has the rain over to all snow by 1am ET.

Other snow amounts from other locations in Indiana.

CITY	RPM	NAM
Bloomington	0.4”	0.6”
Columbus	0.1”
Lafayette	0.1”	0.6”
Muncie	0.5”	0.6”
Terre Haute	0.1”	0.3”

I looked at numbers for St. Louis and they are all 0.0”.

11:15am Weather Update - Thursday Storm Chances

There has been some on-again, off-again chatter about the possibility of snow Thursday in the St. Louis and Indianapolis metro areas.  There may be a slightly better chance for Indianapolis than St. Louis.

Computer models are bringing a storm through the Midwest.  The storm is going to drop some decent snow amounts across eastern Iowa and southwest Wisconsin.  Some areas have potential of receiving a foot or more of snow. (see image)

(Click to see larger version.)

The problem for places like St. Louis, Indianapolis and places in between is the track of the storm.  It is mainly going to be rain.  There could be a few thunderstorms.  In fact, there is the potential for severe thunderstorms over southern/eastern Missouri, extreme southwest Illinois, Arkansas and extreme western Kentucky..  The Storm Prediction Center has a “Slight Risk” area indicated in yellow for severe thunderstorm development.  The main threat will be damaging straight line winds although a few tornadoes can't be ruled out.  The below outlook is valid from 6am CT Wednesday through 6am CT Thursday.

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Here is a look at what the European forecast agency’s global computer model is showing for 6am CT Thursday morning.

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The area of low pressure is centered over northern Illinois.  Rain is basically everywhere right of the blue dashed line.  A line of thunderstorms will go through southern Missouri and Arkansas during the overnight hours Wednesday/Thursday.

Cold air will be filtering down the backside of the low and behind the cold front.  This will allow for some changeover from rain to snow in a few locales.  But look at the next map.  This is 12pm CT Thursday.

(Click to see larger version.)

The low is now centered over Lake Michigan.  The cold front is crossing the Indiana/Ohio border.  Cold air is filtering in to eastern Missouri and southern Illinois.

The model is keeping some precipitation around the St. Louis metro area while the cold air is filtering in.  However, I think the cold air will be late arriving and the precipitation will be early leaving so there can’t be much of a meeting with the two.  I am also thinking there could be a dry slot coming in behind the cold front and the dry air could help soak of some of the moisture.  Right now, I think at best we could see a couple flurries, but even that may be hard to see in St. Louis.

As for Indianapolis… The cold air might be able to get in quick enough to interact with the moisture.  Having said that, the prospects of a lot of snow is low.  I’ve looked at four different computer models and they are all suggesting anywhere from nothing to as much as 0.5” of snow.  Realistically, I think you could be talking about a dusting to 0.25”.

Updated: 11:45am - I want to remind everyone that lives in the areas mentioned above with the severe weather chances to have your NOAA weather radio turned starting tomorrow evening and make sure the batteries still work just in case.

WHITE CHRISTMAS

Everyone keeps asking about the prospects of a White Christmas this year.  The definition of a White Christmas is 1” of snow on the observation at 7am ET/6amET.  This year the chances are looking pretty dismal.  I would put it at less than a 2% chance for Indianapolis, St. Louis, southeast Missouri, southern Illinois, and western Kentucky.

Computer models are starting to spin up a large storm over the Mississippi and Ohio river valleys but guess when it happens.  Eight to nine days out, December 26-27.  If you’ve been following along with my blog this month, this will sound familiar.  The models for weeks have been showing significant storms 8-10 days out and none of them have come to fruition.  I’ll keep an eye on this one but as I’ve said before, don’t hold your breath.

They've Done a U-Ey

The morning computer model data is in and just as I suspected the models have done an "about face" concerning next weeks possible early-week storm.

For the last two weeks I've been saying that the models have been handling the forecast for the first six days fairly well but anything beyond seven days has been downright awful.  That being the case I knew not to get too excited about a storm for December 17-18 too soon because it had been showing up beyond 8-days in the computer models.  That is why I said I would be curious to see if the storm continued to show up in the model runs Thursday (today) and Friday.  Today is Thursday and lets see what the models are showing.

First, NOAA's global forecast model.  The GFS.  The chart below is for 6am CT Monday.

(Click image to see larger version.)

See the storm?  Yeah, me neither.  Where's the surface low the model had been hinting at?  Ummm... It's not there.  It does bring down some cooler air Tuesday for eastern Missouri, Illinois and Indiana, but no snow.  waa waa waa

Same thing with this morning's European forecast agency's computer model, the Euro.  Here is the mode's view at 6pm CT Sunday.

 (Click image to see larger version.)

A couple things to note.  The Euro has sped the system up another 24 hours.  It shows a surface low developing along the Arkansas/Missouri border and then quickly moving northeast along the Ohio River.  This would bring only rain to the "Heartland".  Cold air is well behind the low so there is little chance of snow with the low.

The model suggests that the cold air dive down through Missouri, Illinois, Indiana, Kentucky, western Tennessee and eastern Arkansas and will stick around Monday through Tuesday.

This reminds me of an awesome Peanuts' cartoon I saw a couple weeks ago.  I'm a big Snoopy and Woodstock fan.

(Click to see larger version.)

My "Freak-Out-Meter" is back to 0 out of 10.

Pictures of Meteors

Amongst all of the talk of possible snow next week I also noticed there is an opportunity to see a meteor shower tonight.  It is the Geminid Meteor Shower and conditions across much of the Midwest should be perfect to see it.

Usually I don't post information about meteor showers just because they seem a little over-hyped.  You go outside and look up with hopes of seeing them cross the sky.  However, I found a nice write up on how you might be able to see them easier.

LearnPhoto.ca has some good tips on how you can take great pictures of the meteor shower.  Here is a tease of what you can do to take good pictures.

Pre-Shooting Preparation:
Charge your batteries fully before going out. It's going to be colder at night, and that can affect battery life. Wear some warm clothes, a hat, and gloves. Bring some hot beverages, some friends, and make it a fun outing! At least you'll have someone to talk to between exposures.
Also bring a flashlight or LED keychain light so you can see what you are doing when changing your settings. A headlight looks dorky, but it let's you works with both hands.

Where and When to Go and Sky Conditions:
You want to be as far away from the City/Town as possible to reduce the amount of light pollution. Find a dark road out in the country somewhere far away from street lights.
Obviously it has to be a clear night that you can see the sky. The moon won't be an issue this time around!
You can start to see them after dark, but the best time will be after midnight to 2am on December 14th/15th, when you will have a meteor or two every minute!

Jump over to the article to get the rest of the tips.  Sounds relatively easy.

11:30am Weather Update

Finally just getting a look at last night's run of the European weather agency's computer model.  Not looking good if you are wanting snow in southeast Missouri, southern Illinois, western Kentucky and northwest Tennessee -- the "Heartland".

The Euro has sped the storm up, following what the GFS trended to yesterday.  Here is a look at 12am CT Monday December 17.

(Click the image to see larger version.)

Note the surface low located over western Kentucky.  It is much further north with the low as compared to earlier runs.  Previously, the model had the low in southern Tennessee/northern Mississippi/northern Alabama.  This wouldn't bring snow to the "Heartland".  If anything, it would just be rain.

The model is hinting at very light snow or snow flurries late Monday through Tuesday.  It wouldn't be out of the question that could produce maybe up to an inch of snow if everything was squeezed out.

The Euro is hinting at perhaps 0.5" to 1" of snow from Kansas City along I-70 towards Terre Haute, Indiana Monday through Tuesday but that is extremely "iffy" at this point.

All along I've said not to get hopes up to high with this "storm" until we start to see it in the Thursday/Friday runs of the computer models.  The start of the Thursday model runs aren't looking too promising.  The morning data is coming in.  I'll take a look at it later and see if there is anything noteworthy.

I'm adjusting the "Freak-Out-Meter" to 0.25 out of 10.

10:45pm Weather Update

Just a quick update before I go to bed. Data is beginning to come in off tonight's run of computer models.

So far NOAA's global forecast model, the GFS, is in. If you are hoping for snow early next week in southeast Missouri, extreme southern Illinois, western Kentucky and northwest Tennessee I suggest you look away. This isn't pretty.

Here is what the GFS is suggesting for 12pm CT Monday.



Yes, the model is moving the low pressure area through the Mississippi River Valley quickly. It suggested the same thing on this morning's run as well.

The other thing to notice is the lack of precipitation on the north/northwest side of the low. In fact, you could say there isn't that much moisture with the storm at all.

So what does this mean? It means that this computer model says there won't be any snow, and for that matter rain, Monday or Tuesday next week.

Be sure to check back tomorrow. I'll try to update what the European forecast agency's computer model is suggesting.

My "Freak-Out-Meter" remains at 0.5 out of 10.

- Posted from my iPhone

4:30pm Weather Update

The morning run of both NOAA’s global forecast model (GFS) and the European agency’s (ECMWF) is in.  Both continue to indicate an area of low pressure developing early next week in the mid-Mississippi Valley.

We start our journey with the ECMWF (the Euro).  Generally, this is my preferred computer model for forecasting, especially beyond 48 hours.  The Euro develops an area of low pressure  initially over Oklahoma and Texas Monday afternoon.  The low then moves east.  Below is look at the Euro’s projection of Mean Surface Level Pressure and precipitation at 6am CT Tuesday, December 18.

(Click the image to see a larger version.)

You can see the area of low pressure centered over NW Mississippi.  That is a perfect location for measurable snow in parts of southeast Missouri, western Kentucky and extreme southern Illinois.  The big thing to note, look at the lack of moisture.  The storm doesn’t draw up a lot of moisture.

I also want you to note the grey and blue area in SW Missouri.  This is likely generated by the upper-level low coming in on the NW side of the storm.  Upper-level lows can and often do produce snow.  Usually it isn’t the BIG amounts of snow you see in snow storms, but more of a drier/fluffier snow.

The next image is from 12pm CT Tuesday.

(Click the image to see a larger version.)

The upper-level low is located over SW Missouri/NW Arkansas.  Notice the moisture the model tries to develop on the NW side of the surface low over the “Heartland”.

Just a quick view of the model would suggest 1”-3” of snow in parts of southeast Missouri, extreme southern Illinois, western Kentucky and northwest Tennessee.

The GFS on the other hand is a little quicker with moving the storm through the Midwest.  It is also much drier.  Below is the GFS for 12pm CT Monday.

(Click the image to see a larger version.)

Note it has the area of low pressure over NW Alabama and SW Tennessee.  The location is good but look on the north/northwest side of the storm.  It is dry.  Also notice that we are talking about the storms location 24-36 hours earlier than the Euro.

Here is the GFS for 6pm CT Monday.

(Click the image to see a larger version.)

It is quickly moving east to the coast.  In fact, beyond 6pm CT Monday, it develops are large storm for the east coast.

At this point it is entirely too early to be talking about specific snowfall amounts.  Heck, at this point it is too early to know if this storm will develop for sure.  As I mentioned in my earlier post from today, I want to see the models continue to show the storm on Thursday and Friday’s runs before I get too excited.  I am keeping my “Freak-Out-Meter” at 0.5 out of 10.

7am Weather Update

Just a quick update to show you what last night’s computer models are showing for the “potential” storm next week that I mentioned yesterday.

The European model is still trying to hint at something.  Not quite as strong as previous runs, but there is still something there.

 (Click to see a larger version.)

The GFS tries to bring a developing area of low pressure down out of the Plains before finally getting it’s act together once it hits the east coast.

(Click to see a larger version.)

There would be a chance for some flurries or extremely light snow in southeast Missouri, southern Illinois and western Kentucky but the model has definitely pushed the storm to the east.

My feelings after last night’s developments?  They haven’t changed.  Still wait and see.  If the models continue this for Friday’s runs, then I’ll get a little more excited.  For now, the “Freak-Out-Meter” holds at 0.5 out of 10.

I’ll try to post what the morning runs show later today.