Friday, August 28, 2015

The 10th Anniversary of Hurricane Katrina

A striking image of a helicopter rescue in New Orleans, one of thousands in the days following Hurricane Katrina. The storm caused unprecedented death and destruction in August 2005.
It was 10 years ago on August 29th, 2005 that Hurricane Katrina roared inland in the pre-dawn hours near Waveland, Mississippi just east of metro New Orleans. The storm and its wild aftermath would become the worst natural disaster in modern U.S. history. I have been tracking Atlantic Hurricanes since 1979, and up until that morning in 2005, a little storm named Camille from 1969 was the benchmark hurricane along the Gulf Coast. Camille was the storm weather enthusiasts and those who follow hurricanes knew very well. Camille made landfall near Pass Christian, Mississippi on August 14, 1969 with a 20 foot surge of water and winds over 150mph. The storm virtually wiped out a portion of the Mississippi Gulf Coast along with the lives of 260 people.

Hurricane Katrina would be far worse reaching Category 5 status on the Saffir-Simpson scale, the strongest level in the Atlantic Basin, before "weakening" slightly before landfall. The storm surge, the wall of water that precedes a hurricane, would reach an astonishing 28 feet almost at the same location as Camille. The surge swept away everything in its path, and put a tremendous strain on the levees that surround New Orleans. They would fail catastrophically and put 80 percent of the city under 20 feet or more of water and debris. Damage was complete in many communities and the death toll mounted rapidly with bodies floating in the streets. Officially 1800 would perish from the storm along the Gulf Coast, but unofficially over 3000 are estimated to have died or went missing in the storm and the human catastrophe that followed. It took several days for proper relief to arrive and years for the city to begin recovery. Damage estimates from Hurricane Katrina exceeded 100 billion dollars, the costliest natural disaster in US history. To this day deep scars remain in the city.

Major flooding in Dominica has resulted in at least 2 dozen deaths.

ERIKA SLAMS DOMINICA
So it seems ironic that on the anniversary weekend of Katrina, we have another storm poised to impact the US coast. Tropical storm Erika is approaching the Dominican Republic this morning with 50mph winds. Heavy rain is forecast along the track today with very little change in strength. If the storm holds together in a less than friendly environment, it will approach the Florida east coast early next week. Although weak in nature as far as tropical systems go, Erika produced over 1 foot of rain on the tiny island of Dominica triggering massive floods. The island has been devastated in the last 24 hours with over 24 deaths reported.

Tuesday, August 25, 2015

Tropical activity increasing in the Atlantic basin

The National Hurricane Center forecast track for tropical storm Erika. Erika may approach Florida by the weekend.
It has been a very quiet tropical season in the Atlantic basin, mostly due to the presence of a strengthening El Nino. This feature alters global air patterns and increases the amount of dust blowing off the African continent as well as increasing wind shear along the favorable growth zones for Atlantic tropical storms.

Those factors mentioned above tend to hinder major development in the Atlantic Basin during El Nino years. That being said, we are in the most favorable months for storms to develop in the Caribbean and Atlantic, August and September. This week we have already watched the rapid development and subsequent  rapid weakening of Hurricane Danny. Today we have tropical storm Erika about 800 miles east of the Leeward Islands. Erika has 45mph winds and a gradual increase in strength is forecast this week. A tropical storm watch has been posted for the Leeward Islands. Beyond that and looking ahead to the weekend, if Erika can avoid the sheer that destroyed Danny, she may pose a threat to the US southeast. Before the US she will likely affect Puerto Rico and perhaps the Bahamas.

MONTREAL WEATHER
Monday was a rather warm and muggy day across southern Quebec with temperatures close to 29C (85F). Widely scattered showers and late evening thunderstorms developed along a weak cold front. The precipitation missed L'Ile Perrot with just a trace here, but affected the South Shore and east end of Montreal Island, especially late last evening. This morning we have partly cloudy skies and cooler temperatures at 15C (59F). Expect sunshine today with just a slight chance of an afternoon shower and a seasonable high of 25C (77F). Expect very similar conditions for Wednesday.

Friday, August 21, 2015

July 2015 - warmest in recent memory for the planet

July was warm right across the globe. (NOAA) Click image for more detail.

It is no surprise that July is typically the warmest month of the year on average across the globe. But according to the National Oceanographic and Atmospheric Administration (NOAA), this past July was the warmest for the planet since record keeping began in 1880. With an average temperature of 16.61C (61.86F), July 2015 surpassed the previous record from 1998 by 0.08C (0.14F). It may not seem significant, but it is and you can see the results this summer.

Here in North America we have had widespread heat and drought from B.C. and the northwest to the southwest and into the deep southern portion of the US. Wildfires have been raging out of control in California, Washington, B.C., Alberta and Saskatchewan most of the summer. Temperatures have soared as high as 40C in B.C. and Saskatchewan. Montreal and most of southern Quebec just finished its longest stretch of 30C plus weather in quite some time with officially 4 days at Trudeau Airport but many other locations had up to 6 days. This included high temperatures near 34C on Wednesday and humidex values approaching 40C. On a worldwide scale, intense heat has gripped widespread portions of Europe and Asia this summer. On July 31st in Bandar Mahshahr, Iran, one of the warmest real feel temperatures, (temperature + humidity) ever recorded on the planet was observed at 74C (165F).

In addition to the land temperature, sea surface reading have been 1.35F above the 20th Century average, surpassing the previous high established just last year. Weather you subscribe to the theory of global warming and climate change or not, it is definitely getting warmer for the current period in the life of our planet.

For the short term, after the passage of the cold front last night, we can expect cooler more comfortable weather all weekend. Expect abundant sunshine across southern Quebec and eastern Ontario with high temperatures near 26C (79F) and lows down near 15C (59F). The next chance for showers and thunderstorms will be late Sunday into Monday.

Wednesday, August 19, 2015

Hot & Humid Montreal

A spectacular photo of the intense lightning taken by Quebec Vortex last night on the South Shore in La Prairie. More on Quebec Vortex at this link. 
Our longest and hottest heatwave of the summer is moving into its 5th day in Montreal with temperatures expected to reach 32C (90F) today. If it does, it will set a record high for the date, the previous being 31.7C (89F) in 1960. Yesterday Trudeau Airport had a poorly timed shower around 4pm, enough to drop the temperature down a degree or two, preventing us from a record high by a few tenths of a degree. The official high was 31C (88F) but most other reporting stations around the island including here on L'Ile Perrot, reached 33C (91F).

The airport is typically cooler as the breeze of Lac St. Louis can knock the temperature down a couple of degrees. It remained very warm and muggy overnight with lows in the middle 20's. Last evening a spectacular thunderstorm with lots of vivid lightning moved from the South Shore across the downtown area around 10pm. The storm dumped only 2mm of rain here on L'Ile Perrot but 5mm at the airport in Dorval and 20mm downtown at the McTavish station.

High pressure off the US east coast will continue to pump warm and humid air north into southern Quebec today. The heat advisory remains in effect as humidex values are forecast to exceed 40C (104F) this afternoon. As with Tuesday, there remains a risk of thunderstorms this afternoon and evening. Tonight will be muggy again with warm overnight lows of 24C (76F) in the city. On Thursday a cold front will approach eastern Ontario and western Quebec with showers and thunderstorms by late in the day. It will be warm again with a forecast high of 30C (86F). Cooler air with lower humidity arrives by the weekend.

Monday, August 17, 2015

Hot & humid weather for southern Ontario & Quebec

Warm and humid air streaming north into southern Quebec will make it feel close to 40C in Montreal. (AccuWeather.com)
Some of the warmest air this summer is streaming north into southern Ontario and Quebec. It has been hot right across the country with temperatures well into the 30's and even pushing 40C (104F) in western Canada. Montreal officially managed 29C (85F) at Trudeau Airport on Sunday but it was well over 30C in most other locations away from the typically cooler airport. The high temperature reached 31.5C (88F) at my home on L'Ile Perrot, as well as in St Anicet, Ottawa and Cornwall.

As the heat and humidity continues to build in the east, heat warnings have been issued across Ontario and southwest Quebec. Typically they are posted when a combination of the warm temperatures and elevated humidity make it feel warmer than 40C. It will be that way to start the week for Montreal, Ottawa and Toronto. Hazy sunshine will dominate the weather with perhaps some scattered thunderstorms by Wednesday. High temperatures will range from 30 to 35C (86 to 95F) across the region. Overnight lows will remain warm near 21C (70F). We can expect these conditions through Thursday.

A massive wildfire burning out of control near Oliver, B.C has forced hundreds of evacuations. (Photo via twitter @stucktweet)
B.C. Wildfires
In British Columbia, the hot and bone dry weather has been accompanied by sporadic lightning. Numerous major wildfires have developed over the last week including the Rock Creek fire near Oliver, B.C. This fire, which may have been started by a single cigarette, has consumed more than 3,750 hectares and is 0 percent contained. The fire has forced the evacuations of more than 600 residents and destroyed 30 homes. Since April over 1600 fires have been reported in tinder dry B.C., most of those in the southern interior and Okanogan Valley. The fires have burned over 290 square kilometers. Fires are also burning in neighbouring Washington Sate. Some relief in the weather is expected this week with cooler temperatures and lighter winds as well as less lightning.

Thursday, August 13, 2015

Hot weekend ahead for Montreal & Toronto

The heat and humidity will build as we head into this weekend with highs reaching 30C in Montreal. (AccuWeather)
It has been a rather soggy start to August across southern Quebec. I recorded nearly 36.6mm of rain at my home on Tuesday alone, with 47mm at Trudeau airport. The heavy rainfall of the last 48 hours has brought the monthly total at Trudeau Airport to 87mm. This is well above normal for August and nearly a full months rain in just the first 12 days. The long term average for Montreal is 94mm for the entire month of August. The forecast for the next couple of days will see a chance for more showers and thunderstorms, especially Friday afternoon. Afterwards we will begin to see an increase in temperatures as we head into the upcoming weekend. Sunshine both Saturday and Sunday will push the mercury up to 30C (86F) across southern Quebec. By Monday we may even see a few low 30's for highs, close to 90F from southern Ontario into Quebec and New Engalnd.

WESTERN HEATWAVE
The heat is already building across western Canada. On Wednesday, Lytton, BC had a record high of 40.2C (104F) surpassing the old high of 39.7C. Estevan, Saskatchewan was 36.7C (98F), and Regina 32.9C (91F). The heat will remain into Saturday for the west with highs reaching well into the upper 30's with perhaps an isolated 40C. A strong cold front will bring an end to the heatwave out west by Sunday as it races across the Prairies and into Ontario and Quebec by next Tuesday. Strong to severe thunderstorms are likely with this front as it marches east across southern Canada.

Monday, August 10, 2015

Heavy rain forecast for southern Quebec

Low pressure will move across southern Quebec Tuesday with heavy rain forecast. (AccuWeather)
It was not a terrible weather weekend across southern Quebec, but still far from perfect. There was more sunshine than I expected on Saturday and far more cloud cover on Sunday. Both days featured spectacular starts to the day, but in that unseasonably fall like atmosphere we seem to have lately, clouds and even fog developed by mid-morning and remained in one form or another the rest of the day. Sunday afternoon was the best period, at least here on L'Ile Perrot, as skies cleared and we hit 29C (85F).

The sunset Saturday night in Vaudreuil resembled a painters canvas. Plenty of moisture in the atmosphere lately has created some very busy skies during the day, with rapid clearing at sunset. (ValleyWeather Photo)
As we start another work week, Montreal can expect a mostly sunny day (fingers crossed), along with warm high temperatures near 28C (83F). Enjoy today because the rest of the week looks rather unsettled and at times dismal. Developing low pressure over the US Midwest will move from Lake Erie down the St. Lawrence Valley on Tuesday. Rain will develop overnight in Montreal and persist all day Tuesday. Amounts will range from 20-30mm along the St. Lawrence Valley to as much as 60mm in the Laurentians and north of Quebec City. Environment Canada has posted heavy rainfall warnings for the region north of the St. Lawrence River. The rain will be accompanied by the occasional rumble of thunder as well as gusty winds. With the rain, temperatures will remain below normal with a low of 18C (65F) tonight but only up to 21C (70F) on Tuesday. The remainder of the week looks unsettled with slightly below normal temperatures and the ever present risk of showers or thunderstorms.