Winter Storm Watch Sunday night thru Monday

Saturday, December 13 -- 4:00PM

Winter Storm Watch from Sunday 6PM to Monday 4PM...

All signs still pointing to a significant Ice Storm for our region for late Sunday night into Monday. To be honest, I have a hard time believing some of the numbers being thrown at us. For instance, tomorrow's high temperature will likely break 60 degrees, and then the cold front is supposed to pass, and the temperature will plunge into the 20s by Monday morning. A 40 degree drop? That's not exactly unprecedented, but we will need every last bit of that temperature drop to get the expected ice accumulations. If the temperature "only" drops 35 degrees instead of 40, then this will just be cold rain.

Predicting the effects of an Ice Storm is tricky business. Forecast models are pretty poor at anticipating how cold the air will REALLY be. To give you an idea, since Sunday's high temperature will be around 60 degrees, for us to get significant ice accumulations Monday morning, the temperature actually needs to fall into the lower 20s (say, 22F) during the rain event to overcome that prior warm air presence. Yes, yes, I realize water freezes at 32 degrees. But entropy is at work here. Ever notice that if you put a glass of water into a freezer it doesn't immediately freeze? Same thing.

Then again....

Interested if schools will be closed? My guess is the following scenario will play out:

• This Ice Storm scenario will "mostly" come true. Come early Monday morning, the temperature will be around 27, and freezing rain will be accumulating as ice on the ground. At 4AM or so, we will have a light glaze, and forecasts will be dire
• By 6AM, it will still be moderately raining, with the temperature around 25, grassy areas will be covered with ice, but streets will be only slightly bad. School district officials will envision kiddies standing at bus stops, covered in ice as if Frozone from The Incredibles had sprayed an Ice Ray their way. The school officials will hit the panic button, and there will be widespread school closings.
• By noon-time, most of those school officials will walk outside, see that there is no ice on the streets, scratch their heads and say, "We called off school for some cold RAIN?!?"

The margins for error are razor thin here. Just a few degrees either way will make a huge difference. But if I was a betting man, I would say there is a 60-70% chance of widespread school closings, and for a very short period of time Monday morning, those decisions to close schools will seem justified. What worries me is come mid-day Monday, a lot of school officials will be second guessing their decisions.

Remember, weather fans, there is nothing I want to see more than a thick sheet of ice covering everything, to the point that I need to break out my ice skates to take the dog outside. I am just not convinced we will get those extra 5 degrees.

-WD

Ice Storm Sunday into Monday?

Friday, December 12 -- 10:00AM

Greetings all! Here we are, back for another season of exciting Winter Weather events...

All weather sources point to a fairly significant Ice Storm threat to the STL region beginning Sunday night, and lasting into Monday mid-day. The National Weather Service (NWS) has been advertising this for the last couple of days.

Could it happen? Sure. The odds are in our favor. But before we break out the champagne, I am a little worried about a few of the details.

On the negative side:

• First off, this weekend is supposed to be mild, with temperatures in the upper 50s on Sunday afternoon. It would not shock me if we touch 60 due to the strong southerly winds predicted. This will thaw the ground to the point that it will take quite a bit of freezing precipitation to change the ground temperature.
• Second, with all of this warm air in place Sunday, I am a little worried about the accuracy of the Arctic air intrusion predicted by the models. Models commonly predict an Arctic "Express Train" of cold air, but in reality it usually turns out more to resemble the "Saint Louis Zoo train."
  
• Also, the timing of the onset of frozen precipitation has me concerned: the switchover from rain to freezing rain/sleet is not predicted to occur until after midnight early Monday morning.
• Forecast models have historically not done a good job predicting freezing rain/sleet events 3 days before onset, particularly in November/December.
  

On the positive side:

• That strong southerly flow Sunday will bring the necessary moisture to the Midwest for us. We won't have to overcome dry air before precip starts, as the air will already be saturated.
  
• My prediction that this will be a colder-than-average winter plays into our favor (take that, Global Warming)
  
• My prediction of a wetter-than-average also plays into our favor.

In the final analysis, I am not skeptical that we will get a lot of moisture, and therefore a lot of precipitation. I am just not yet convinced of the cold air intrusion. Three days out, it is simply too early to make that call.

But if you are interested in my prediction, stay tuned, and I will put out a prediction in the next 24-36 hours.

Keep your fingers crossed!

-WD

Here it Comes!

Monday, March 3 -- 4:30PM

Winter Storm Warning until Tuesday evening....

What may be the most significant winter storm in a number of years will effect the STL region tonight and Tuesday. All signs point to an axis of heavy snow extending from southwest Missouri into southern Illinois, with STL smack-dab in the middle. We might even see thundersnow!

http://www.crh.noaa.gov/wxstory.php?site=lsx

The one thing that worries me is the rule "Don't forecast major snow until you see the flakes falling from the sky." With this system, we are relying on a "trowal" (a TRough of WArm air aLoft) to develop, and that will be the trigger for the heavy snow. That has not formed yet, but all of the models are predicting it to happen. That is why I have this much confidence.

As this is the case, I am going to go along with the NWS and predict heavy snow.

Drop Dead Prediction:
60% chance - 6+ inches of snow
20% chance - 0-5"
20% chance - sleet/snow/freezing rain not amounting to much

There is a better than average chance that we will get somewhat more than the 6 inches of snow in my prediction. Dare I say 12 inches? If so, it would qualify as one of the top ten 24 hour snowfalls of all time in STL.

Could it happen???

Think Snow!!!

-WD

Winter Storm Tuesday

Monday, March 3 -- 8:30AM

Winter Storm Warning from noon Monday through 6PM Tuesday....

A complicated weather scenario is taking shape over the midsection of the country. We started the morning with mild temperatures and rain, and by Tuesday afternoon it is entirely possible we will have 6+ inches of snow on the ground.

I love March! In like a Lion, out like a Lamb, as the old saying goes.

So, will we get the 6+ inches of snow? I am thinking yes. The various models have had extraordinary run-to-run consistency, as well as good concurrence. Here is the good news:

1. Plenty of moisture to work with in the low levels of the atmosphere. This is constantly a problem in our part of the world. How many times has a forecast called for snow, only to have it be so dry outside that all of the snow evaporates before ever reaching the ground? Shoudn't be an issue with this storm.
2. Cold air intrusion appears to be on track.
3. Low pressure over New Mexico forecasted to move our way. This is the classic "Southwestern storm" scenario. This kind of storm track is the one where we get the most snow in the STL region.
4. The "Farmington Rule." One of my rules is "Don't predict snow for STL if they are not predicting snow for Farmington." The thinking behind this rule is that forecasters have a habit of over-predicting the southward push of cold air. So the fact that 4-6" of snow is in the forecast for Farmington is good news for us.
5. As it is early March, thundersnow is a real possibility. The dynamics for this storm are right for it. If we do get thundersnow, the total accumulation will be high. So 6+ inches is not a stretch.

Now the bad news:

1. Time horizon. This will be a long storm that starts off slowly, with only a minor nuisance of wintry weather Monday, and ends with a BANG. The major portion of this storm will not begin until Tuesday morning. Will schools close Tuesday before any snow starts? Especially since many school districts feel like they got burned recently by closing when the wintry weather failed to materialize? I only predict the weather; I don't predict how humans will behave.
2. Models prone to error. Only a slight change in the storm track can alter the entire weather picture for us. But like I said, the models have mostly been predicting the same scenario for numerous consecutive runs.

I want one more model run before I make my Drop Dead prediction. But it is looking good to me!

Think Snow!

-WD

Winter Storm Watch for Thurs/Fri

Wednesday, February 20 -- 11:30AM

Winter Storm Watch for Thursday morning thru Friday afternoon...

Well, the NWS is sure putting the "fear of God" into us with all of this "Winter Storm" talk. I gotta be honest, though....it doesn't look to be anything terribly significant at this point.

I have a feeling that if we get anything, we are going to see quite a bit of sleet with this storm. And while sleet is slippery, and the accumulation and freezing of a layer of sleet can create havoc with travel, the truth is this almost never happens. When we get a lot of sleet, I typically lament that we got robbed of a major snow storm.

The good news is that the POTENTIAL is there for this to be a real mess of a storm. We are in the bullseye for snow, sleet and freezing rain.

What does all of this mean? It means that right now I don't have a good "bead" on this storm. I need another model run before I can make a prediction.

I'm thinking mostly sleet, but wishing for mostly snow!

-WD

Winter Storm Thursday?

Tuesday, February 19 -- 12:40PM

Hmmm. Not so sure about his system for Thursday. That's both good news and bad news.

First, the bad news:

1. Looks like this system will be another one with bad timing, with precip happening during the daylight hours.
2. There does not appear to be a ton of moisture associated with this system

Now, the good news....

1. It's PLENTY bleedin' cold for this system to bring wintry precipitation.
2. There is a lot of uncertainty in the models, which means things could be worse than they currently predict
3. The storm has not even come on shore from the Pacific yet, so lots can change
4. The most precip is forecasted to occur along the I-70 corridor

So, keep your fingers crossed. But all current indications are that this will be more of an inconvenience than a Winter Storm. Let's hope that changes!

-WD

Sorry, All. This one is NOT "The Big One"

Monday, February 11 -- 9:30AM

Winter Weather Advisory in Effect through Tuesday morning.....

I will cut right to the chase and tell you that school likely won't be cancelled due to this so-called storm.

I almost was not even willing to blog about this "storm," due to its insignificance. All weekend, I followed the models and the forecast updates, and there was really no reason (in my feeble mind) to get excited about this storm. The main energy of this storm is south of STL by 50-100 miles, and that is where the Winter Storm Warnings are. All we have is a lousy Winter Weather Advisory. The difference between a Winter Storm Warning and a Winter Weather Advisory is like the difference between a severe thunderstorm and a moderate rain shower.

But, my fans simply DEMAND and update, so here it is.

The timing of this storm is all wrong, both from a duration and onset standpoint. This will be a long storm with light precipitation throughout, quite unlike the heavy snow we experienced during the January 30th storm. Since the precipitation should be light, and spread out over such a long period, the streets should be fairly easy for the plows to get cleared. None of this bodes well for school closings.

Drop Dead prediction:
50% chance - 2" of snow, along with a light glazing of ice...but no big deal
20% chance - 3-5" of snow (IF this happens, it could close schools)
15% chance - less than 2" of snow, along with a little ice
15% chance - nothing

Sorry weather fans, but this just ain't "The Big One."

-WD

Winter Storm Wrapup

Friday, February 1 -- 1:35PM

I've been hearing a lot of smack-talk lately that I am just "lucky," that I don't know what I am talking about, and all I am good for is parroting that blowhard Dave Murray. If you don't wanna hear my predictions, that's cool! I can always keep 'em to myself!

For all of you weatha hatin suckas out there, here's a recap. What was I right about? In a word, everything. I predicted 5" of snow for us. We got 5.5 inches of snow at our house....OK, I was off by a half inch. I predicted widespread school closings for Friday. And what do we have? Widespread school cancellations today....are you enjoying your day off, that I predicted on Monday?

I am the Champion, my friends! What else needs to be said? I am the greatest Weatherdork out there!

Til next time, I remain yours in weather....

-WD

My Drop Dead prediction

Wednesday, January 30 -- 10:50PM

I've had a long day, and I will have another long one tomorrrow, so I am not going to bore you with my usual weather geekiness. As you might have surmised, the forecast calls for ...uh....snow!

The Drop Dead Prediction:
40% chance - Exactly 5 inches of snow
20% chance - 1-4" of snow
20% chance - more than 5 inches
20% chance - nada

The forecast and all of the models are calling for 7-9 inches. Looking at those models, I'm a little surprised they think that. A lot of the moisture may be sucked up by rain to our south along the Gulf Coast states. For us...If we get anything, it should all be snow. That's the good news.

I think 5" should do it. And 5" is enough to close schools.

Enjoy the day off on Friday, suckas!

-WD

Winter Storm Watch Thursday Afternoon/Evening

Wednesday, January 30 -- 10:45AM

Winter Storm Watch Thursday....

All signs continue to point toward a major winter storm for the country's midsection. The latest model runs have the heaviest snow bands just south and east of the STL metro area:

http://www.crh.noaa.gov/wxstory.php?site=lsx

Now, the wonderful thing about forecast models is that they are fraught with error. Let's hope that the storm track is about 25 miles farther north than currently predicted, and that we fall within that band of heavy snow!

Either way, I think it is fairly safe to predict 4-5" of snow in the STL area. Two issues I see:

1. Timing....in terms of whether this storm will cancel schools. Per current thinking, most of this snow should fall before midnight Thursday. If that is the case, and we only get 4-5", it may be that the roads can be reasonably cleared before the morning rush hour. Then again, we have not had a severe winter, and many schools have some built-in snow days still remaining in reserve. Hmmmm.....
2. Tight snow gradient....The further Northwest you travel, the amount of snow will quickly diminish to zero. For instance, if you live in Bowling Green (sorry about that, if you do, for many reasons), you might not see a flake out of this. How far South will this "zero line" turn out to be? It's still possible that STL will miss out completely....not likely, but possible.

I will get out my Drop Dead Prediction once the 4PM soundings from the NWS come out. At that point, I will have enough of the data I need.

Think Snow!!

-WD

Snow, Baby. Snow.

Tuesday, January 29 -- 7:00PM

What a crazy day. At noon, it was 73 degrees (the new record high for this date), and by 4:30PM the temperature had plummeted to 23. For all of you math-impaired types out there (like the wife), that's a 50 degree drop in a little over 4 hours. That's not a record temperature drop, but that's still just plain nutty. And did you get a load of this freaking WIND? All I can say is WOW!

This bodes well for the upcoming winter storm that will effect the region Thursday night into Friday. Plenty of cold air in place...plenty of Pacific moisture combining with Gulf moisture headed our way...All indications are that this storm will have a heavy band of 8-10 inches of snow somewhere in the region....the million-dollar question is, "where will that happen?"

Answer: I have no freakin idea. 50 miles north or south of a given line could be the difference between a ton of snow, and just a few flakes.

But...I said it yesterday, and I will say it again: if I was a betting man, I would lay odds on widespread school closings in the STL metro area for Friday. I'd throw a buck down on that!

When I know more, I will post an update.

Til next time.....Think Snow!

-WD

Gear Up, Suckas! Winter is Comin' back with a Vengeance

Monday, January 28 -- 6:00PM

All models are pointing to a major winter storm for late this week. This storm, if it materializes, will be a "Southern Storm," capable of bringing heavy snow to our area. Oh, YEAH!

With cold air up over Alberta headed our way, precipitation from this storm (still currently over the Pacific) should fall as all-snow.

Batten down the hatches! If I was a betting man, I would lay 50/50 odds that schools will be cancelled Friday. That's what you wanted to hear, wasn't it?!?

Stay tuned.

-WD