Weather Discussion for Saturday March 5th 2011

A soggy Saturday for Southern Ontario with 25-40mm of rain expected today with up to 50mm possible in areas just north of the lake Erie shorelines.

Rainfall Warnings continue for all of Southern and Eastern Ontario.

 A stalled frontal  system is responsible for the higher amounts of rain across the region and as cooler air begins to move into the region later today and into the overnight, rain will change to snow. Current indications from the latest computer models suggest at least 5cm of snow from Windsor through to the GTA with slightly higher amounts north of their into Barrie and cottage country.

Precipitation will come to an end early Sunday morning and skies will clear later in the day.

Temperatures will go on a rollercoaster ride through the coming week along with a mixing of precip. Watching a system for Wednesday and another for Friday. The Wednesday system is looking like rain, however the Friday system currently looks like snow for most of Ontario with the exception of the extreme southwest of the province.

The warmest temperature in Southern Ontario for yesterday was:

Windsor +7°C  @4pm

Regional Stats from Environment Canada:

• Toronto               3.6 / -2.7
• Hamilton            3.8 / -5.9
• London               3.4 / -5.7
• Windsor             6.7 / -3.2
• Sarnia                4.6 / -4.1
• Peterborough    3.2 / -6.4
• Muskoka            2.2 / -6.6 

 Computer Model Temperature Anomoly for Southern Ontario over the next 10 days.

0.4 degrees above normal

RainFall Warning for Hamilton

City of Hamilton
9:33 PM EST Friday 04 March 2011
Rainfall warning for
City of Hamilton continued

..Significant rain tonight, Saturday and Saturday night..

A substantial rain event is slated to begin tonight as a front stalls on a line from Central Lake Huron through Georgian Bay tonight and Saturday. Plenty of moisture migrating northwards from the gulf of Mexico combined with decent lift along and ahead of the front will cause widespread rain, occasionally heavy, to envelop much of Southern Ontario. It will become heavier overnight in the southwest and then spread northeast affecting much of Southern Ontario on Saturday. Eastern Ontario will experience the heavier rainfall later Saturday into Saturday night. Widespread rainfall amounts of 25 to 40 mm are expected tonight through Saturday night. A few areas will likely exceed 50 mm.

The rain will change briefly to snow before ending Saturday night.

The warning criteria is 25 mm within 24 hours (fairly conservative criteria) based on the fact that runoff is more significant in areas where snow pack is minimal and the ground is still frozen.

Weather Discussion or Friday March 4th 2011

A very tricky weekend forecast is in store for Southern Ontario as a moisture laden system approaches the great lakes region. Temperatures will be mild enough around the lower lakes for an all rain event at the start, however north of the GTA temps may be just cold enough for snow to mix in or just plain snow.
Some areas around the Bruce Peninsula and north of Parry Sound have Winter Storm Watches issued.

Temperatures around the lower lakes should make it a few degrees above zero today and into the mid-single digits for Saturday. For areas north of the GTA, rain may change to some snow during the afternoon as colder air begins to move in.

Sunday appears to be the day for the most snow around  the region. Tricky to get accumulations from this, but looking at the current computer models, it appears that most areas from Windsor to the Golden Horseshoe could get 4-8cm with the lesser amounts towards the Windsor area of Southwestern Ontario.

Normal temperatures are on the rise now and it becomes increasingly difficult for snow in the southern areas of the province. With the higher sun angle, snow doesn't last long either on the roads.
Speaking of snow... here is a really cool high resolution sat image from MODIS showing the snow cover around the Great Lakes and over eastern Canada and the US. Note the ice cover on the lakes and the "snow-hole" around the GTA.

The warmest temperature in Southern Ontario for yesterday was:

Collingwood -2°C  @4pm

 

Regional Stats from Environment Canada:

• Toronto               -2.5 / -12.5
• Hamilton            -4.0 / -13.5
• London               -4.6 / -14.8
• Windsor              -2.5 / -8.5
• Sarnia                 -3.9 / -13.9
• Peterborough     -4.1 / -18.5
• Muskoka            -5.0 / -27.2 

 Computer Model Temperature Anomoly for Southern Ontario over the next 10 days.

0.5 degrees above normal



Daily Weather Discussion - Tuesday March 1st 2011

High Pressure in Control Today; Colder Mid-week; Significant Storm Late Week

The storm system that brought milder temperatures, rain and even some isolated thunderstorms to southern Ontario yesterday in the early morning hours has since moved off to the east and in it's wake, colder air has returned to Southern Ontario. Nothing to substantial, but cold enough to freeze what had melted on Monday. Generally 10-20mm of rain fell, with some higher pockets towards the SW of the province that experienced isolated thunderstorm activity.

High pressure is in control today with sunshine across Southern Ontario and temperatures around the freezing mark with some centres just above by a couple degrees. Winds will also be generally light as the ridge moves over the area.

A cold front approaching in the overnight hours will likely bring a few flurries across the province, but nothing significant to be heard off. Temperatures will drop to below seasonal values for Wednesday.

As mentioned last week, there is a significant storm system approaching for the end of the week.

Current computer models are suggesting a milder flow of air, thus making this an all rain event. Temperatures are expected to approach double digits by Saturday ahead of the cold front associated with this approaching storm system.

Models are suggesting 20-30mm of rain beginning Friday and continuing into Saturday. There may be a change over to snow Saturday as colder air begins to filter in from the west.

The tricky thing is... the snow/rain line is just north of the GTA. Areas around Barrie northwards towards cottage country and around the Kawarthas may see more snow from this system.

The exact track is not yet certain so a slight shift southwards could make the difference between rain or snow for the region. I will continue to monitor this approaching storm over the next couple of days.

So, with today being the first day of Meteorological Spring (Astronomical Spring begins March 20th), what can we look forward to in the coming months? Well... Environment Canada has released a statment saying that a large portion of the country will see colder than normal coditions throughout the Spring. Here is the link to the article.http://www.cbc.ca/news/canada/story/2011/02/28/canada-weather-colder.html?ref=rss

                                                                                                                                                                

The warmest temperature in Southern Ontario for yesterday was:

Long Point +7°C  @5am

Regional Stats from Environment Canada:

• Toronto               2.6 / -4.5
• Hamilton            2.6 / -5.0
• London               2.2 / -6.4
• Windsor              2.6 / -3.6
• Sarnia                 1.6 / -5.7
• Peterborough     2.6 / -4.5
• Muskoka            0.4 / -9.6 

 Computer Model Temperature Anomoly for Southern Ontario over the next 10 days.

0.3 degrees above normal