Tuesday, October 13, 2015

Much colder weather & frost on our doorstep

It was a perfect Thanksgiving Monday on L'Ile Perrot with sunshine and record warmth. (ValleyWX Photo)
Depending on where you were in southern Quebec on Thanksgiving Monday, you may have had the warmest October 12 on record. The temperature reached 24.9C (77F) here on L'Ile Perrot but 23.5C (75F) at Trudeau Airport just missing the record of 23.9C (76F) set in 1961. No matter where you were across the region it was a perfect way to end the summer season for good. I say that because much colder air is on the way. Looking ahead I don't see another opportunity for temperatures that warm. We are rapidly loosing daylight as well which tends to limit just how warm it can get.

Frost & Snowflakes
This morning a series of cold fronts is off to our west and will begin the slow process of lowering temperatures this week. Expect showers to develop today and persist into Wednesday. The temperature will reach 18C (65F) today, but only 12C (54F) Wednesday and no better than 5C (41F) by Saturday. The weather will be rather unsettled all week with limited sunshine and periodic showers. I am quite confident that by Saturday or Sunday morning we will see a hard frost in most regions of southern Quebec including metro Montreal. Overnight lows will drop below freezing for the first time this season. There is also the chance for a few snow showers across the mountains of southern Quebec and New England. Looking ahead into next week milder temperatures are forecast to return but not the 20 plus weather we just experienced.

Monday, October 12, 2015

Warm Thanksgiving then below normal temperatures return

The warm Thanksgiving in Montreal will be replaced by much cooler air, clouds and showers as the weeks moves along.
It will be an Indian Summer type day across southern Quebec, Ontario and New England on this Thanksgiving Monday. Temperatures will be on the rise aided by gusty southwest winds up to 50km/h and sunshine. Expect warm highs of 21C to 24C (70 to 75F) across the region, well above the normal high for Montreal of 13C (55F). The brief warmth is being caused by strong low pressure moving out of the Prairies and across the Great Lakes. Montreal has a slight chance at the record high for today of 23.9C (76F) set in 1961.

This system has a strong cold front associated with it that is plunging temperatures back to reality behind it. Over the weekend warm air rushed north ahead of the system pushing temperatures to record levels across the west. It was downright hot in the northern US plains states with Fargo, North Dakota reaching 97F (36C) smashing a 72 year old record of 85F from 1973. Temperatures pushed into the middle to upper 20's across southern Manitoba and Saskatchewan before the front arrived. The front arrived with strong to severe winds sweeping across the region. Gusts were reported to 109km/h at Leader and 104km/h at Assiniboia in Saskatchewan. In Alberta a gust to 111km/h occurred at Alliance and 89km/h in Edmonton.

In Montreal the sunshine of today will be replaced by clouds and showers for the rest of the week. After the warm temperatures today, we will see gradual decline in highs and lows through next weekend. By Saturday the high will only be 6C (43F) in Montreal with lows near freezing and frost expected. We may even see the first snowflakes of the season across the mountains of New York, Vermont, the Laurentians and Townships by late Friday night.

Wednesday, October 07, 2015

Clean up continues in the Carolinas - frost for Quebec

I apologize for the slow week in the blogging department. It has been a rather busy week at work. I hate it when life gets in the way of weather!

The weather has been rather quiet in Montreal with partly cloudy skies and seasonable temperatures. A large area of high pressure over central Quebec has deflected any storm activity well to our south and east including hurricane Joaquin. Sunshine will prevail again on Thursday with temperatures a little cooler than they have been of late. There is even a risk of frost away from the St. Lawrence Valley, particularly across the lower Laurentians. The low is expected to be near 2C (36F) with highs around 13C (55F). Our extended period of dry weather will end Friday as low pressure moves into the region with widespread rain. At this time it looks like 15-25mm of rain will fall through Friday evening. Skies will clear out for the weekend with temperatures near normal.

Historic flooding from last weekend in South Carolina. (Charleston Post Courier Photo)
The clean up continues in South Carolina after epic rainfall last weekend. Some locations recorded 1000 year rain events with as much as 27 inches (over 685mm) of rain in less than 5 days. That amounts to nearly an entire years worth of rainfall here in Montreal where the annual average is 784mm. The rain destroyed homes and washed away roads including a portion of Interstate 95 as well as infrastructure, claiming at least 17 lives. Flooding was also reported in North Carolina and in coastal communities from Georgia to Maine. The heavy surf and coastal flooding was caused in part by hurricane Joaquin passing well offshore. The heavy rain was the result of an upper level low over the southeast US and a persistent ribbon of moisture moving inland from the tropical Atlantic. Many rivers remain above flood stage with more damage expected in the coming days. Evacuations have been ordered in many areas with as many as 13 dams failing so far in South Carolina. Damage is expected to be in the billions of dollars.

While Montreal has had no rain so far in October, portions of the east coast were inundated.

Saturday, October 03, 2015

Joaquin to move out to sea - high pressure dominates in Montreal

Coastal flooding in Atlantic City, New Jersey on Friday. (Reuters News)
What a difference 24 hours can make in weather forecasting. Computer models had communities up and down the east coast from South Carolina to Nova Scotia in a state of emergency at the prospect of a land falling Joaquin. But now all models are predicting the storm to head out to sea and spare all of us a direct hit. Hurricane Joaquin remains a powerful storm this morning with 125 mph winds located 165 miles (270km) northeast of San Salvador, Bahamas. The storm pounded the northeast Bahamas for the last two days with fierce winds and heavy rain. Damage is extensive in the eastern portion of the Bahamas.

Meanwhile the news is not perfect for the east coast of the US. They are still dealing with a major upper level low over the southeast that is producing historic rainfall. Up to 2 feet of rain has fallen along the North and South Carolina border with more forecast. The rain has produced major flooding in the Carolinas. Along the coast high surf has produced widespread coastal flooding from Massachusetts to North Carolina. The heavy surf is a result of the flow of air around Joaquin and a persistent northeast fetch of air and water off the Atlantic. Strong high pressure located over Quebec is helping deflect Joaquin out to sea but is also producing the pressure gradient that is driving the Atlantic into the coast from the Maritimes south. Flooding is expected to continue throughout the weekend.

The good news for Montreal is the only effects we will see from both Joaquin and the strong low over the southeast is a cool northeast wind up to 50km/h. Montreal and most of southern Quebec can expect nothing but sunshine as high pressure holds all weekend. Temperatures will range from 12 to 14C (52 to 56F) for daytime highs and cool plus 3 to 5C (38 to 41F) for overnight lows through Monday.

Thursday, October 01, 2015

Joaquin now a major hurricane

A NOAA satellite image of a strengthening hurricane Joaquin in the central Bahamas early Thursday morning. 
It has been a rather quiet Atlantic hurricane season to this point, as is typical during El Nino years. But as forecasters always remind us, all it takes is one storm to make the season memorable or infamous. Will Joaquin be that storm? In less than 24 hours the system has gone from a tropical storm to a major hurricane. The Category 3 storm with winds in excess of 120 mph is drifting southwest in the central Bahamas this morning. The Bahamas will have strong winds, pounding waves and torrential rain for the next 24 hours. Joaquin is a small but dangerous storm for that region today with life threatening wind and rain. Beyond that the storm is forecast to move northward and increase in forward speed through Friday. Interests all up and down the east coast should be monitoring Joaquin. At this time computer models have the storm track all over the place from out to sea to landfall along the Outer Banks of North Carolina. An average forecast path takes the storm into the waterlogged middle Atlantic and eventually into New England and southern Quebec by Tuesday. That scenario is far away and Joaquin has several chapters to write before that point. I have been tracking Atlantic hurricanes since 1979 and will watch this one closely and update the blog as needed.

Before Joaquin arrives on the weather scene, Montreal is looking at much cooler air to start October but with plenty of sunshine. Temperatures are expected to be near the freezing point at night and into the low teens for highs through Saturday.

Wednesday, September 30, 2015

Major east coast rain as Joaquin forms in Atlantic

A poorly timed cold front produced heavy rain and snarled traffic during the Tuesday evening commute in Montreal. (ValleyWX)
 Tuesday was very warm across southern Quebec, perhaps the last really muggy day of 2015. Temperatures reached 25C (77F) in Montreal, well above the normal high of 17C (63F). A cold front plowed into the St. Lawrence Valley during the evening commute with very heavy rain. Nearly 20mm fell in less than one hour in Montreal, with 35mm as of 7am this morning. As much as 51mm fell in Kemptville, Ontario with the frontal passage. Light rain continues in Montreal this morning, but the heavy rain has settled south along the US border and into New England. The front has stalled over those regions and is acting like a conveyor transporting copious amounts of tropical moisture into the northeast. Rainfall may exceed 100mm (4 inches) from Pennsylvania and New York into southern New England and the Maritimes. Numerous flood watches and warnings are on place including heavy rain warnings for the Eastern Townships. High pressure will slowly clear out southern Quebec over the next 24 hours, but it will be much cooler along with stiff northwest winds up to 50km/h. Low temperatures in Montreal will drop to 5C (41F) with highs around 14C (56F).

The current NHC forecast track for Joaquin.
Tropical Storm Joaquin
Another major player in the flood potential shaping up along the east coast will be the future track of tropical storm Joaquin. The storm developed in the Atlantic this week and is located 240 miles east northeast of the Bahamas this morning. Joaquin has 70 mph winds but is strengthening and will likely reach hurricane status today. Joaquin is expected to drift west southwest over the next 24 hours before moving north. The storm may impact portions of the eastern US and Canada beginning as early as Sunday with torrential rain. One forecast model has the storm approaching northern New England and southern Quebec by late Monday. Another has it remaining over the Atlantic. This storm will have to be monitored very closely, especially for coastal regions from North Carolina to Nova Scotia. The National Hurricane Center forecast models have Joaquin reaching Category 2 strength with winds in excess of 100mph. With most of the area from the middle Atlantic north being saturated with the current rain event, the potential for major flooding is very real.

Monday, September 28, 2015

A more fall like weather pattern for Montreal

A ship passes under the full harvest moon around 7pm along the St. Lawrence Seaway off L'Ile Perrot. (ValleyWX)
The lunar eclipse begins shortly after 8pm last evening. This photo was taken from L'Ile Perrot. (ValleyWX)
It was a beautiful night to watch the rising of the harvest moon and the total lunar eclipse on Sunday evening. The celestial event, 30 years in the making, did not dissapoint. I went to Pointe-du-Moulin on the tip of L'Ile Perrot and took the photos you see above and below. I was using my old reliable Canon Power Shot 35mm Digital with the zoom maxed out. It was a perfect night, warm temperatures for late September and just a light breeze lapping the waves against the shore, simply stunning.

The lunar eclipse reaches totality just after 10pm last evening. This photo was taken from L'Ile Perrot. (ValleyWX)
After what was basically an extension of summer during the month of September in Montreal, we are looking at a more seasonable weather pattern over the next few days. Monday and Tuesday will be cloudy with scattered showers and warm temperatures near 23C (73F). By late Tuesday a cold front will cross the region and tap into moisture moving up the east coast. Expect steady rain to develop by late in the day Tuesday and continue overnight. Amounts may exceed 25mm over Ontario, Quebec and New England. Skies will slowly clear Wednesday but it will turn much cooler with highs only in the middle teens. Temperatures will average below normal to end the week with even a risk of frost on a couple of nights as lows fall into the 2 to 4C (36-40F) range. More rain and cooler weather is possible to end the week. We may have just seen the last of the really warm air until next spring.