Cool, windy and showery

Summer one day, Fall the next. What a difference a day can make. A strong cold front crossed the region yesterday evening and that erased the warmth and humidity and replaced it with cool and windy Autumn like conditions. Clouds mixed with some sunshine across the region today along with gusty winds up to 60km/h at times. There was also periods of Lake Enhanced Showers crossing the area from time to time. These showers were caused by the cooler air moving over the warm waters of Lake Huron and stretched all the way to the Golden Horseshoe. You can see by the surface map from earlier today that the isobars are fairly tight across the region which is why the winds were quite strong today.

Taking a look at the temperatrures across the region today...

Toronto		Hamilton
19°	15°	16°	13°
London		St. Catharines
16°	13°	18°	14°
Extremes Across Ontario Yesterday 21°C 6°C Point Petre Big Trout Lake

Gusty conditions should continue on Thursday with some isolated showers once again, however they will be more widespread. Winds should diminish by the afternoon hours and sunshine return. Sunshine is expected into the weekend, but temperatrures won't be that warm. Normal values for this time of year are 22°C... that will be the warmest we will likely see, probably Saturday, during the next 10 days.

In International Weather News....

Tropical Storm Igor has formed off the African Coast and is moving westwards in the open Atlantic. Igor is forecast to become a Hurricane by the weekend, but is no threat to land any time soon.

Here is today's look a the tropics...

Summer returns, but only for a day!!

It's like Mother Nature flicked a switch and Summer returned. A large area of low pressure to the north of the region was responsible for the warm southerly flow of air that boosted temperatures to well above normal values across the Golden Horseshoe and for all of Southern Ontario for that matter. Several area saw temperatures above the 30°C mark today. Winds were also an issue as they gusted upwards of 70km/h at times during the afternoon hours.

Damage in the Sarnia region due to
strong winds on Sept 7th.

That was enough to cause a tree to fall on a van in the Sarnia area today along with other minor damage to older trees that may have already been weakend from the winds that whipped across the region last Saturday. Winds were generally in the 40 to 50km/h range during the afternoon across most of the area, however some higher gusts were reported in all areas.

As the cold front raced eastwards during the afternoon some thunderstorm activity fired up ahead of it. Severe thunderstorm watches and warnings were issued for potions of Southern Ontario, but the GTA was spared. Frequent lightning and strong winds were the main things being reported by these storms as they moved through. There seemed to be a break in the line of storms over the Golden Horseshoe as not a drop of rain was observed from Hamilton to Toronto.

 Taking a look at some of the temperatures around the region for today....

Toronto		Hamilton
30°	16°	29°	17°
London		St. Catharines
29°	17°	31°	20°
Extremes Across Ontario Today         32°C           1°C Windsor Nagagami

The warm temperatures will be short lived as a cold front approaching from the west will erase the humidity and the heat and replace it with much cooler and drier air. The atmosphere will remain a bit unstable on Wednesday however as the cooler air rushes across the warm waters of lake Huron and Georgian Bay. This will create some "Lake Effect" showers downwind of the lakes and will likely stretch far inland as well. Some of these scattered showers will reach the Golden Horseshoe area during the afternoon. Temperatures will only make it into the mid teens on Wednesday, but it will feel much cooler with the winds and overcast conditions during the afternoon hours. 

Temperatures in the longer range are expected to be close to or slightly below the normals for this time of year. No large temperatures swings are apparent on the computer models for the next 10 days at least.

Looking at some international news...

The tropics are fairly quite (relatively speaking) since we are in the peak of Hurricane season. Here is a look at the topical systems currently in play. Tropical Storm Hermine came on shore along the Texas coast with torrential rains being the main threat causing some flooding in the areas. Max winds were around 100km/h as Hermine made landfall. The remants of Tropical Storm Gaston continue to move westwards and have the potential for re-generation as it enters the very warm waters of the Caribbean.

Flooding in parts of Australia is threatening 300 properties in Shepperton and residents are preparing for the worst. The state premier warns that the floods are not likely to ease over the next 7 days.

Ariel shot of the flooding in Shepperton, Australia

Labour Day - The Unofficial End of the Summer Season

Well it's Labour Day already. I say already, because it just seems like a few weeks ago it was the Victoria Day weekend kicking off the start of Summer. Now, Summer is drawing to a close. Temperatures have been kind of cool this long weekend as well as an upper level low has kept cloud cover up and temperatures down. Also no thanks to a sharp cold front that passed through the areas Friday night.
Some scattered showers are continuing across Southern Ontario today with temperatures hovering around the 20° mark for many centres.

Warmer air will begin to move into the regions for Tuesday as the Jet stream lifts above the region. Humidity will also return with values into the mid 30's for the afternoon hours. I wouldn't be surprised if some shower or thunderstorm activity pops up across Southern Ontario. There is a cold fron that is poised to cross the region Tuesday night and depending on the time of passage, we may see some good storm activity. Environment Canada says there is the chance that some storms may reach severe limits with damaging wind gusts and torrential downpours.

Here is a look at Yesterday's reported conditions and extremes across Ontario...

Toronto		Hamilton
20°	10°	19°	8°
London		St. Catharines
20°	10°	21°	10°
Extremes Across Ontario Yesterday 21°C 0°C St. Catharines Upsala

Taking a look at the tropics for today....

What a difference a day makes; Hurricane Earl makes landfall in Nova Scotia

What a difference a day makes. A cold front moved through the regions last night and has taken us from Summer to Fall in a matter of 12 hours. A strong pressure gradient behind the cold front is causing strong gusty winds up to 70km/h at times across the regions. The cool winds blowing across the warm waters of lake Huron are also causing some Lake Effect Showers to form inland and are stretching all the way to the Golden Horseshoe region.

Temperatures today are only hovering around the low to mid teens across the area, however with the strong winds, it's feeling quite a bit chillier.

The strong winds should subside a bit overnight, but continue to be gusty into Sunday as well. Lake Effect showers should continue during the overnight and into the morning on Sunday before winds begin to diminish and subsequently end the showers across Southern Ontario.

Hurricane Earl came ashore near Lunenberg, Nova Scotia this morning at around 1030am local time. Earl was a minimal category 1 hurricane, but was soon downgraded to tropical storm. Extensive damage has been reported around the Halifax area with several trees downed. Winds have gusted upwards of 120km/h across the region and will continue to be gusty today as Earl makes it's trek northeastwards into the Northumberland Staight and eventually into the Gulf of St. Lawrence.

..Cooler temps moving in; Windy Saturday; Hurricane Earl Weakens

After 3 consecutive days of heat and humidity across Southern Ontario, things are about to change. A cold front is ready to sweep away the heat and erase the humidity as it crosses the region today. Temperatures today will be in the mid 20's, feeling into the 30's, but tomorrow will only reach the mid to high teens with strong winds gusting to 60km/h at times.
Ahead of the front, showers and some embedded thunderstorms have developped. Gusty winds are also associated with these storms along with heavy rains. The cooler air will make it's way into the region later this evening and Im sure will be a welcome relief for many. It will be time to turn off the Air Conditioners and open the windows.

As mentioned above, Saturday will be noticeably cooler as northwesterly winds bring in much cooler air. Winds will be gusting upwards of 60km/h at times on the back side of the low pressure area responsible for the cooler weather. There is also the chance of some lake induced showers or thunderstorms. The same process that creates lake effect snows will be in motion tomorrow as cooler air races across the very warm waters of lake Huron and Georgian Bay. This is also a good set up for some waterspouts to form, so boaters need to be on the lookout for that as well. Waterspouts, although much weaker than tornadoes can still be very detructive to boats.

Hurricane Earl continues on it's northeastward trek towards Nova Scotia. Now a Category 1 storm, although significantly weaker, Earl will still pack a punch to the northeast. Check out this awesome satellight image take this afternoon. The low pressure system crossing the Great Lakes right next to Hurricane Earl over the Atlantic.

Above Normal Continues; Cooler for the Weekend; Earl to strike Nova Scotia

Heat and Humidity Continue....

Above normal conditions continue across Southern Ontario and around the Golden Horseshoe today. A southerly flow ahead of a slow moving cold front will help to keep the temperatures into the high 20's to near the 30 degree mark for all centres across the region. Humidity will also make it feel into the high 30's.

A HUMIDEX ADVISORY remains in effect for the area as humidex values will be near 40 for the 4th day in a row. Scenes like this were common place across Lake Ontario and up through cottage country as people were trying to beat the heat.

Showers and thunderstorms are likely to develop along and ahead of the cold front as it interacts with the warm soupy airmass. Behind the front, much cooler air will filter into the regions. There is the chance that some of the thunderstorms that do develp will reach severe limits, but the main threat is strong gusty winds. The timing of the front will also play a big part in the amount of storm activity we recieve. It's expected to arrive overnight and early morning, when daytime heating is at the minimum.



Hurricane Earl aiming for Nova Scotia

The main weather story is Hurricane Earl. Currently a Category 4 Hurricane, the path of Earl is expected to take it right over Nova Scotia. Earl is expected to weaken before it hit's, however it still could be a Category 2 storm. Residents are preparing for the worst as memories of Hurricane Juan still linger in many peoples minds.
There still remains some time that Earl could strengthen to a Category 5 hurricane before entering cooler waters. It will be going through an eyewall recplacement cycle today and the new eyewall will be forming as it crosses the warm Gulf Stream.

Yesterday's Reported High and Low Temperatures
September 1st 2010

Toronto           33°  /  21°
Hamilton         31°  /  21°
London           30°  /  20°
St. Catharines  31° / 23°
Windsor          33° / 22°
Muskoka         32° / 19°

Extremes Across Ontario
September 1st 2010

33°   -   Collingwood
7°    -   Big Trout Lake

Hot and Humid Continues; Much Cooler for the Long Weekend; Hurricane Earl

Hot and Humid Continues....

The calendar may say September, but people have been flocking to the beaches to escape the oppressive heat and humidity that has resided over the region for the past few days.Some of the hottest temperatures of the summer have occured over the last couple of days in Southern Ontario and around the Golden Horseshoe and will likely occur again today. Toronto reached a high of 34.5°C on Monday and that was the hottest temperature recorded in the city for the entire summer. Humidex values were also much higher, making it feel like 42.

Other cities such as Hamilton, St. Catharines and London were not far behind with temperatures in the low 30's with humidex values of 40 or more as well.

Humidex Advisories have been in effect from Environment Canada since Monday and will remain in effect for today.

A huge area of High Pressure is responsible for the hot and humid airmass that is over Southern Ontario. Just look at the size of the area of high on the surface map, extending from the Gulf of Mexico right up into the province of Quebec.

Southwesterly flow is pumping extra moisture into the region as well keeping dewpoints high and humidex values into the high 30's and low 40's.  These are the types of highs we usually see in mid-summer that give us the hottest temperatures and extended periods of hazy sunshine.

Much Cooler for the Long Weekend...

A cold front approaching from the west will move through the regions on Thursday and this will help to clear the air so to speak. Much cooler temperatures behind the front will move in for Friday and the weekend. In fact, Saturday appears to be the coolest day with daytime high's only in the mid teens giving a real sense that Fall is just around the corner. Current forecasts suggest high teens will last into Labour Day before a warming trends takes hold for next week.


Hurricane Earl

Hurricane Earl, a Category 4 Hurricane, with maximum sustained winds of 217km/h is affecting the islands in the Carribean. Earl is expected to make a northerly turn and move up the eastern seaboard and has the possibility of impacting Nova Scotia sometime Friday or Saturday. Current model guidance suggests the path will take it right over the province and may make landfall as a Category 1 Hurricane.  Right behind Earl is Tropical Storm Fiona. Barley a Tropical Storm at 60km/h sustained winds, Fiona is expected to take a similar path of Earl, but is not expected to be nearly as strong.

Yesterday's Observed High and Low Temperatures:

Toronto              33°  /  23° 
Hamilton            31°  /  19°
St.Catharines    33°  /  20°
London               31°  /  18°
Windsor             33°  /  24°
Muskoka            30°  /  16°