Friday, January 31, 2014

Env. Can. Snowfall warning:

Ottawa South - Richmond - Metcalfe
3:15 PM EST Friday 31 January 2014
Snowfall warning for
Ottawa South - Richmond - Metcalfe issued

15 centimetres of snow on Saturday.

A low pressure system is due to track through Windsor and Toronto Saturday evening and then continue eastward into Quebec. Snow ahead of the system will move into the Huron - Perth and Waterloo - Wellington regions Saturday morning. In Peterborough the snow will begin late in the morning and in Ottawa early in the afternoon. Snowfall accumulations of near 15 centimetres are expected with this system. Snow will end from west to east Saturday night and may continue a few hours into Sunday morning over Eastern Ontario.

Noon Friday post.

Primarily about Saturday.   The regional models are coming into focus and it looks most of southern and eastern Ontario will get at least a few inches.  For Ottawa, it will start tomorrow afternoon and continue overnight.  It's looking like Ottawa will get 6"+ so travel may be impacted Saturday evening through Sunday morning.

Two models:


RGEM (Can)
With respect to the Wednesday snow, it's currently looking like Ottawa will catch the northern edge as the bulk of the storm will impact the US NE.

Stay tuned

Thursday, January 30, 2014

Afternoon update

By the looks of the latest, the map in the previous post may be right.  But we'll see when the short range models get in their wheel house.

First snow map for Saturday

I am sceptical of these amounts.  Rather I think the maps will be updated later showing the band of snow shifting south, meaning we will be on the north side of the heaviest band.  The latest NAM has trend the storm south and stringing it out.   Currently I am thinking we'll get 5-10cms Saturday.

As for the storm next Wednesday, the models are trending towards a solution that has an initial system heading up towards the lower Great Lakes from the SW and a secondary low developing off the coast sucking the energy from the first.   If correct, we'll again miss the heart of the snow as it will primarily be in the US NE.

Oh, and there's a similar type storm showing up on the models for next weekend as well.

Stay tuned.

Tuesday, January 28, 2014

Virtually no change from yesterday...

The models have aligned on Saturday's system, more or less.  One is more vigourous than the other but it looks at this point a 3-6" (8-15 cm) storm late Saturday.

The bigger deal is around next Wednesday where all medium range models that I have access to (GFS, Euro, Canadian and Japanese) are in agreement that something signficant is coming to our general vicinity next week Wednesday.  How that exactly turns out remains to be seen.  However it's fun to note that the Euro is giving us a 12"+ storm

On another note, there's snow in places that usually doesn't get any:

Monday, January 27, 2014

Pattern shift...

After the next couple days, we will see a shift in the pattern somewhat.  The mean trough position which has been over the Lakes since the thaw, will shift west towards the center of the continent, meaning we will on the eastern side of the trough.  What this means for us is less cold air and a bigger chance for bigger storms that come from the US SW.

In fact, the Euro and the Canadian are in league to bring us such a system Saturday night which, if the current run is true, will give us 6" of wet snow.  The GFS has it pushed south.

There is also a bigger system on the models for next Wednesday.

Stay tuned.

Thursday, January 23, 2014

A coup for the Canadian...

All the models are pretty much in line with the Canadian.   As such it looks like we are hit by two clippers, one early Saturday and one later Sunday, each bring 2-4" of snow, perhaps 6" lollipops in places if a heavy band stays in one spot.

Wednesday, January 22, 2014

Models are trending to the Canadian.

It's increasingly looking like the blind Canadian found the nut before the others.   The latest Euro is inline with the Canadian with a clipper system center arriving over south Lake Huron and crossing to Lake Ontario late Sunday.   The GFS has trended northward in its latest run with the storm center passing just south of Lake Erie.

If the Can and Euro are correct, then we'll likely have two 2-4" snowfalls (with potential of 6" if ratios are high), one early Saturday and one late Sunday. 

Then VERY cold after that.

As I was saying about Great Lake ice...

And the cold is just beginning...

Monday, January 20, 2014

Where the real snow is happening...

Not shown shown on this map but Nova Scotia and the rock of Newfoundland will get hammering with 12-18" of snow from this storm on Wednesday

Hold the phone....

Models are showing a clipper clipping us with 3-6" of the white stuff on Saturday.  Not exactly a storm but we'll take what we can get.

And for a funny, the Canadian has another clipper for Sunday following quick on the heels of the Saturday clipper, taking it through south/central Ontario to eastern Ontario, giving most of the area another 6".  On the other hand, the GFS and Euro have this piece of energy weaker and well to the south of Ontario.

The next couple weeks

The story for the next couple weeks at least for our area (and much of Ontario) will be the cold.  No major snow events are currently predicted.  Below are the days 1 thru 5 mean temp anomoly and the day 6 thru 10 mean temp anomoly, as predicted by the GFS Ens. 

Winterlude will at least have a good start.

Friday, January 17, 2014

Great Lake Ice

Here is the current state of Ice on the Great lakes (which is above normal by the way):

Here is the current temperature of the Great Lakes:

Given the temperature over the next 2-3 weeks, we will be seeing a massive increase in Great Lake Ice, rivalling the cold 70's.

Monday, January 13, 2014

Day 10-15 temps

The map show the day 10-15 mean temps at 850 mbs (approximately 5000').  While admittedly nobody lives at 5000', it can be used to show the surface temperature anomalies as well.

Quick post...

January likely to end very cold as another "polar vortex" drops in on us next week.  Winter ain't done.

Saturday, January 11, 2014

Kemptville vs Nepean

Kemptville got up to 8C this afternoon.   Ottawa A/P is barely at 1C.  Cold air settling in the valley?  Could be.

The Euro has dropped the Tuesday storm...

Looks like after Monday, we will get colder but not Arctic air.  Systems will be dominated by Alberta clippers which we haven't seen much of yet this year.

Friday, January 10, 2014

Thursday, January 9, 2014

Interesting period coming up

As the cold high moves off to the east, a southerly flow of air will begin.  A bit of warm invection snow will bring a skiff of snow to our south tomorrow.   The real deal will happen on Saturday as temperatures spike as we will be on the warm side of a system going NE over Lake Superior.   We will not an insignificant amount of rain.  Combine that with melt, we will likely get some flooding in the streets.   Thankfully this time there won't be as huge a crash in temperatures this weekend as last.  It'll get only a little bit below zero on Sunday before getting above zero again on Monday.

Tuesday gets controversial.  The Euro and JMA are calling for a system to wind up and hit us with a rain turn to snow storm (giving southern Ont another big snowstorm)   The GFS and Can. have split the energy into two systems that really aren't significant...

It will get cooler again later next week.

Wednesday, January 8, 2014

So how cold was it?

And this is including the brief warmup on Monday.

Temperature Anomoly, Jan 1 to Jan 7

Tuesday, January 7, 2014

Midweek mirth...

In case you've been hibernating, the current cold wave is supposedly caused by a "polar vortex".   Nothing technically incorrect about that but also not too interesting or unusual.  There's been plenty of cold outbreaks of a similar vein.   However, the MSM is having a heyday...

The antidote, humour:

The next while...

If you think back to my initial discussion on the winter outlook, it is looking pretty accurate. 

Here is a reanalysis map for December temperatures:
Ottawa had more than 87 cms of snow in December.  Our average December snowfall is 57.2 cms.

We are going to see more back and forth temperatures for the rest of the month.  This weekend is going to get mild again and likely rain on Saturday.   I don't see any major snows for a while on the models and deep cold won't come back again until after mid month.

Monday, January 6, 2014

snowfall warning??

Good old Lake Effect snow.  By the looks of the radar, we will get some.

Ottawa North - Kanata - Orléans
8:18 PM EST Monday 06 January 2014
Snowfall warning for
Ottawa North - Kanata - Orléans issued

Snowfall and local low visibilities this evening.

An area of heavy snow is moving across Eastern Ontario this evening. Local snow amounts of 10 to 15 cm are possible in a few hours. As well, visibilities will be locally near zero in snow and blowing snow.

Environment Canada will continue to monitor this evolving situation and update warnings accordingly.

Flash freeze update 2

As of 11 AM, it's -3C, a drop of 9C since 8AM.

Flash freeze update

Cool down will come sooner than I expected. It looks like it's already started in Ottawa.   It has dropped two degrees in the last hour.  Kingston has dropped 7 degrees in the last 3 hours.

Flash freeze...

Most everything is covered in ice this morning even though it's several degrees above zero... But the cold is coming.  The cold front has reached Peterborough which has dropped at least 5 degrees in the last two hours.  I'm guessing our temps will start dropping by noon.

Sunday, January 5, 2014

Ice rain in Ottawa

As of 10:00 PM Sunday, it is ice raining.  Has been for a while given the good coat so far on my car.   It is -4C.  Question is whether it gets above 0C by morning.

Regional win...flash freeze warning.

All models, regional and global, are converging on the regional track from yesterday.  That is, over eastern Lake Erie, Golden Horseshoe to eastern Algonquin Park.  The main band of snow is currently in Michegan heading NE.

What that means for us is that the snow today will change to freezing rain to rain overnight into the morning.   The chance of school cancellation tomorrow depends on the freezing rain to rain ratio and when exactly that change happens.

Also of note is the temperature crash on Monday.   If you don't clear your snow piles from where you don't want them, you're going to have piles of ice instead.  There is also the driving danger of a flash freeze as well.  We will go from a morning temperature of a couple degrees above 0 with rain to the negative teens in the evening. 

Saturday, January 4, 2014

Regional vs Global battle

The global models have pretty much remained stable with the storm track and timing that I described in my previous post, except that the start of the snowfall is likely to happen during the day on Sunday.

The fly in the ointment are the regional models, which are higher resolution versions of their global counterparts.  Due to the higher resolution, an error will get more amplifed (compared to global models) the farther out from the base period.  As such, the regional models are just starting to get into the zone of reasonable accuracy with Monday's storm.  However, they are showing the storm going NE over Lake Erie into central Ontario, putting us well east of main snow and definitely in the warm sector.

Here is the latest snow map.  It's based on the Global models.

Friday, January 3, 2014

Messy, messy, messy

The storm is going to be a VERY messy storm for all of southern and eastern Ontario.  Currently the models are converging on a track that take the storm center just south of Lake Erie and over Lake Ontario to eastern Ontario by Monday morning.  To the north and west of the storm track will be heavy snows with high ratio liquid equivalent values due to the very cold air behind this.   If the current track and timing holds, the we will be getting 10-15 cm of snow overnight Sunday with mixed precip Monday morning, changing back to snow Monday afternoon, after the storm center passes.
Here is the latest snow map from A/W.  Not to many arguments with it at this point.   Hoping for a 50 mile shift south though.  Note that it goes only to Sunday and doesn't include the precip Monday.

Thursday, January 2, 2014

First snow map

For Monday's storm:

Models converging for Monday's storm

Looking like a very messy storm for us on Monday as the models have converged on a Eastern Great Lakes track which will give us mostly snow with perhaps a mix of ice rain thrown in.

Stay tuned.

Wednesday, January 1, 2014

Another Storm update

Today/tomorrow's storm going well south of our area:

Still a divergance in tracks for Monday's storm.  The Euro has gone for a SW to NE track that is west of us, the GFS has it east of us and the Canadian and JMA has it right between the two.  As such the Canadian GEM has the biggest storm for us.