Frost Advisory for tonight..

Env. Can. Advisory:

2:01 PM EDT Friday 22 May 2015
Frost Advisory in effect for:

• Ottawa North - Kanata - Orléans
• Ottawa South - Richmond - Metcalfe

Frost may destroy fruit crops, vegetables, and other plants.

Wide spread frost is expected. Under clear skies and calm winds, ground temperatures overnight and early Saturday morning are expected to be at or a few degrees below freezing. The exception is for areas very close to the Great Lakes where temperatures will remain a couple of degrees above freezing.
Take preventative measures to protect frost-sensitive plants and trees.

Weather Advisories for Frost are issued when temperatures are expected to reach the freezing mark during the growing season, leading to potential damage and destruction to plants and crops.

Map courtesy of Accuweather.  I think Southern Ontario will be hit harder than implied by this map, eg Guelph and area will be hitting neg values.

Colour me surprised...not!

http://www.ctvnews.ca/canada/ottawa-invests-134m-to-upgrade-weather-forecasting-1.2191816

Env. Can. trash

People have noticed that I pretty consistently hammer the Env. Can. forecasts.  Yet again, there is good reason.
Their current published forecast for Thursday and Friday has little to no snow on it, just a 40% chance on Thursday.  Yet every model, including their own, has enough precipitation falling Thursday night into Friday morning to give us several inches of light fluffy snow Friday morning.

The main problem in this lies with the fact most broadcasters parrot the Env. Can. forecast and people make plans accordingly.  In this case, the roads will be quite snotty Friday morning.

Update to Chance of showers

It's included in Env. Can. 11 AM forecast:

Today, 2 July: Cloudy with 30 percent chance of showers early this afternoon then a mix of sun and cloud. Wind becoming southwest 20 km/h this afternoon. High 28. UV index 8 or very high.

Chance of showers

Unlike the Env. Can. current forecast (Sunny. Becoming a mix of sun and cloud this morning. Wind becoming southwest 20 km/h late this morning. High 28. UV index 9 or very high.), there is a chance of getting wet this morning.

Env. Can. reads my blog*

*probably not.

7:15 AM EDT Tuesday 10 June 2014
Special weather statement in effect for:

• Ottawa North - Kanata - Orléans
• Ottawa South - Richmond - Metcalfe

Significant rainfall possible beginning late Wednesday.

A low pressure system is expected to affect Eastern Ontario beginning later in the day on Wednesday and continuing until Friday. Rain at times heavy and isolated thunderstorms will be associated with this system. The slow moving nature of this system may result in significant rainfall amounts.

At this point, it is still too early to say which locations will be affected the most and how much rain will fall. However, some regions may see amounts in excess of 40 millimetres.

Env. Can. stick yer head out the window.

Their latest forecast for Ottawa, released at 3:30 PM, a half an hour ago at time of writing:

Tonight, 16 May: Rain ending after midnight then cloudy. Low 9.

Anyone sticking their head out the window would know that the rain has already pretty much stop.  Even looking at the Env. Can. radar image would give a clue...

Alright, stick a fork in it..

This winter's done.   I think I can say that with a high degree of confidence.  While temps may be below normal more often than not, I'm not seeing any more snow events on the horizon.

Yesterday did not break any records, temperature or snowfall.  At least according to Env. Can NAV CAN sensors at the Ottawa A/P.   I am reasonably comfortable with their temperature measurement  but their snowfall measurement falls short, I believe.  The official snowfall amount was 0.6cms yesterday.  From personal observation, that is a little light.  My estimate was that something between 1 and 1.5 cms accumulated.

Today will have a record cold measurement.

Latest Env. Can. statement

6:22 AM EDT Tuesday 15 April 2014
Special weather statement in effect for:

• Ottawa North - Kanata - Orléans
• Ottawa South - Richmond - Metcalfe

After a long awaited taste of summer, winter returns with a snowy vengeance.

A sharp Arctic cold front has passed through Southern Ontario ushering out the mild air of the past few days. In the wake of the front, northwesterly winds are returning much colder Arctic air to the regions, with temperatures plunging to below freezing early this morning from the Dunnville through the Greater Toronto area to Renfrew areas and northwestward. The colder air and northwesterly winds will make temperatures fall to below freezing across Niagara and the rest of Eastern Ontario during the day today.

Meanwhile, a disturbance tracking up along the line of this cold front is bringing another area of precipitation with it. As temperatures drop to below freezing, rain showers are transitioning through a brief period of freezing rain and ice pellets to snow over Southern Ontario early this morning, and over Eastern Ontario later this morning or early afternoon.

Indications show that a snowfall of 5 to 10 cm for much of Southern Ontario will occur today. A total of 10 to 15 cm of snow are possible for some areas east of Georgian Bay.
Driving conditions will deteriorate quickly as the freezing precipitation and snow move in. Motorists should be prepared for hazardous winter driving conditions due to low visibility in areas of heavier snow, and accumulating snow on untreated roads.

The snow will end over all regions late in the day. Winter's Victory will be only temporary, as temperatures will moderate back up closer to normal by the end of the week.

Env. Can. weather statement...

11:47 AM EDT Monday 14 April 2014
Special weather statement in effect for:

• Ottawa North - Kanata - Orléans
• Ottawa South - Richmond - Metcalfe

Winter battles again with spring, as temperatures go up and down like a roller coaster and strong winds blast across the regions today.

The low pressure system that has brought heavy rain to some and twenty degree temperatures to others will bring winter-like weather to most before it exits the province Tuesday afternoon.

It will be a very warm day for some regions today, particularly over Eastern Ontario where temperatures may soar into the mid twenties, with readings in the low 20S in the Greater Toronto to Peterborough and the Trenton areas.

However, a big change is coming as winter clashes again with spring. Showers, accompanied by a few wind gusts to 85 km/h and an isolated brief 90 km/h gust, are moving across the regions. This will herald an end to the first taste of almost summerlike weather across the regions. The showers will move into Eastern Ontario later this afternoon.

A very sharp Arctic cold front will sweep across Southern Ontario this afternoon then move into Eastern Ontario this evening. Temperatures will plunge quite dramatically as a result, with values dropping to near freezing or a bit below from roughly the Toronto area and west by Tuesday morning.

As a result, showers will begin to change over to a few centimetres of snow from near Georgian Bay to Lake St Clair tonight with the transition zone reaching Eastern Ontario later Tuesday morning. During this transition, there is a risk of a few hours of ice pellets or freezing rain.

 

In addition, after the changeover to snow, a few centimetres are likely by the time the snow tapers off later on Tuesday. There will be enough snow to whiten the ground in many areas. There is some potential, based on latest indications, of total snowfall amounts reaching 10 cm especially over higher ground to the southeast of Lake Huron and Georgian Bay. Temperatures will be sharply colder on Tuesday with afternoon values expected to be near or below freezing as winter pushes spring well to the southeast of the regions.

Motorists should be prepared for a quick return to winter driving conditions, especially in areas that receive a period of heavier snow. Untreated roads and surfaces may quickly become partially to mostly snow covered and slippery.

Still no agreement...

Among the models on whether we will get snow in the first half of next week.    The Euro is now the most gung-ho, the GFS second and now the Canadian is mostly missing us...  We are in for some rain on Sunday   Whether we get snow is dependent on whether the third disturbance that's riding the front will be timed with the arrival of cold air.

I don't agree with it entirely but for what it's worth, here is the Env. Can statement (see highlight):

3:21 PM EDT Friday 11 April 2014
Special weather statement in effect for:

• Ottawa North - Kanata - Orléans
• Ottawa South - Richmond - Metcalfe

Significant rainfall from late Saturday night to early Tuesday morning.

Several disturbances with associated significant rainfall are expected to move across Southern Ontario in the next 3 days. There is still considerable uncertainty to determine exactly how much rain each disturbance will bring. However, indications at this time suggest the total rainfall amounts from late Saturday night to early Tuesday morning could be very high. Regions north of a line from Southern Lake Huron to the Ottawa and Prescott regions could end up with 50 mm to 75 mm. Rainfall amounts are expected to drop off sharply south of this line.

Please consult your local conservation authority or Ontario ministry of natural resources district office for more information on spring flood conditions.

In addition, rain is expected to switch to snow Monday night over regions east of Georgian Bay. Algonquin and Burk's Falls - Bayfield Inlet regions could end up with 5 to 10 cm of snow by Tuesday morning.

Environment Canada meteorologists will continue to monitor the developing systems closely and update this statement when necessary.

The public is advised to monitor future forecasts and warnings as warnings may be required or extended.

Please monitor the latest forecasts and warnings from Environment Canada at www.weatheroffice.gc.ca.

Env. Can. weather statement

See highlight.

 

10:00 AM EDT Monday 07 April 2014
Special weather statement in effect for:

• Ottawa North - Kanata - Orléans
• Ottawa South - Richmond - Metcalfe

A moisture-laden Texas low is setting its sights on Southern Ontario.

The disturbance expected to affect Southern Ontario is currently over Western Kentucky and will intensify and track toward the Lower Great Lakes today. The most likely trajectory is across Ohio to Lake Ontario by Tuesday morning. Rain is expected to develop over parts of Southern Ontario this afternoon, reaching Georgian Bay this evening.

A significant general rainfall of 15 to 25 mm is likely over much of Southern and Eastern Ontario with the higher amounts likely closer to lakes Erie and Ontario. Rainfall warnings have been issued northeast of Lake Ontario where 25 to 35 mm of rain are forecast.

The rain will likely change to a heavy wet snow this evening mainly over the higher terrain of the Dundalk and Haliburton Highlands. A significant accumulation of 5 to 10 centimetres appears likely in these areas before it tapers off early Tuesday. Locally higher amounts are possible, especially over the Bancroft through Algonquin Park area, as well as the higher ground southwest of Collingwood including flesherton, Singhampton and Shelburne. Snowfall warnings may be required.

On a more spring-like note, the warmest weather of the season is likely on Thursday to the south of Georgian Bay, quickly erasing any memory of the snow on Monday night. Temperatures are expected to climb into the mid to upper teens, but will likely be more muted east of Georgian Bay.

Graphic vs text Env Can forecast...

Taking a quick look at the Env. Can. graphical representation of forecast, one would think that there is no rain coming in the next couple days and it's going to be just beautiful the whole time. 

However the text portion says this:

Today, 1 April

Mainly sunny. Increasing cloudiness this afternoon. Wind becoming east 20 km/h gusting to 40 late this morning. High 6. UV index 6 or high.

Tonight, 1 April

Mainly cloudy. 60 percent chance of showers late this evening and overnight. Wind east 20 km/h gusting to 40. Low zero.

Wednesday, 2 April

Mainly cloudy. Clearing near noon. Wind southwest 20 km/h becoming light late in the morning. High 6.

April fools?

Quick post

Env. Can. is pulling out a 5-10 cm dump tonight in their latest forecast.   I am having a hard time believing it.  Most short term models are giving us at most 5cms before the change over to rain tomorrow morning...

We could look a whole lot whiter again tomorrow...until it all melts tomorrow afternoon.

Quick morning post

Today/tonight's snow/rain.  It's going to be sloppy.  The majority of the snow will be to the north of us in the higher elevations of the Gatineau hills.  The rain/snow line will over Ottawa tonight as temperatures increase.  As a result I don't think we get as much snow as currently predicted by Env. Can (5-10cm).  TWN is more in line with my thinking with 2-5 cms.

For Saturday, things are continuing to line up for 10cm + snow fall Saturday morning.  I think Env. Can is out to lunch with its rain or snow forecast as I (and TWN) think it's all snow.

Environment Canada Seven Day forecast.

Hilarious.

Env. Can. flip

Their 3:30 PM forecast release for the weekend:

Saturday, 1 March:  Cloudy with 60 percent chance of snow. Low minus 17. High minus 3.

Sunday, 2 March:  A mix of sun and cloud. Low minus 10. High minus 7.

Just sayin'.

I really don't get Env. Can....

Here is their weekend forecast issued 8:52 AM today:

Saturday, 1 March:  Sunny. Low minus 18. High minus 5.

Sunday, 2 March:  Sunny. Low minus 9. High minus 5.

You would never know that their own Canadian model has about a 1/2 inch liquid equivalent precipitation in that time period which would give us a few inches of snow.

The other models also show precipitation during that time period, albeit with slightly different timing and intensity.

The Weather Network does have the snow in their forecast.

Monday's bigger storm has slid south of us on the modelling...:(

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.

Winter storm watch from Env Can

Ottawa North - Kanata - Orléans
3:41 PM EST Monday 25 November 2013
Winter storm watch for
Ottawa North - Kanata - Orléans issued

First winter storm of the season Tuesday night into Wednesday.

A low pressure system over the Gulf of Mexico will bring the first significant snowfall of the season to much of Eastern Ontario Tuesday night and Wednesday.

Snow is expected to rapidly overspread the regions Tuesday evening, and then taper off from west to east on Wednesday.

Total snowfall amounts of 15 cm or more are expected in most places with up to 25 cm possible in the Ottawa area. An exception is in the St Lawrence Valley where warmer air could cause the snow to change to rain for a period, reducing amounts. There will also be the risk of freezing rain in easternmost sections.

Furthermore, some areas will see blowing snow on Wednesday.

Poor travel conditions are expected to develop Tuesday evening and continue into Wednesday.

Please refer to your local public forecast for further details.