Monday, April 30, 2012

More unsettled weather Tuesday.. thunderstorms possible..

A low pressure system over southern Saskatchewan will push a warm front across southern MB tonight, bringing another round of scattered showers into the Red River valley. There's even a chance of some scattered thunderstorms overnight as more humid air spreads in. Showers and scattered thunderstorms will taper off Tuesday morning with cloudy to partly sunny skies expected through midday. Additional showers and thunderstorms are possible later in the day into the evening, especially southeast of Winnipeg. In fact, some strong to possibly severe thunderstorms are forecast for areas south of the international border Tuesday, including much of Minnesota.

Sunday, April 29, 2012

Scattered showers likely today.. isolated thunderstorms possible near US border

A generally cloudy and breezy day is on tap today across Southern Manitoba as a low pressure area over far southwest Manitoba moves slowly northward this afternoon. Scattered showers rotating around the low are expected across southern MB today although rainfall amounts should be light and much of the day should be rain free. Near and south of the US border, there is a risk of isolated thunderstorms later this afternoon into this evening as some breaks in the cloud cover help destabilize the airmass. Some of these thunderstorms may cross into far southern RRV later today into this evening although they will be weak and short lived. Drier conditions are forecast Monday over southern MB before another round of possible showers and thunderstorms moves in on Tuesday.

Sunday, April 22, 2012

20 degree weather to start the week..

It'll be a nice mild start to the week as some warm air spreads across the Prairies into southern MB. Temperatures are expected to climb to the 20C mark in Winnipeg and the RRV Monday and Tuesday before some cooler weather moves in mid week. Moderating temperatures are forecast for the end of the week again. Normal high temperatures for Winnipeg are now around 13C.

Friday, April 20, 2012

Some rain moving in Saturday mainly south and west of Winnipeg..

Sunny and dry conditions today will give way to increasing clouds tonight as the next weather system moves into southern Manitoba overnight. This system is expected to bring 5-15 mm of rain across southern MB Saturday, with the main swath expected from the Riding Mtns area through the western and southern RRV. Some light rain is possible in Winnipeg Saturday but most of the rain is expected to fall mainly west and south of the city. Drier and milder weather is forecast for Sunday into early next week, before the next chance of showers by Tuesday.

Saturday, April 14, 2012

Strong storm system south of border to impact areas south and east of Winnipeg Sunday

A strong storm system developing over eastern Colorado today is expected to spawn an outbreak of severe weather over the central American Plains today with a high risk of severe thunderstorms especially though Kansas, Nebraska and Oklahoma where violent long tracked tornadoes are possible. The storm system is expected to track into South Dakota tonight then into Minnesota and Wisconsin on Sunday. Widespread rain is expected on the northwest flank of the storm with areas of heavy rain possible over the Dakotas tonight into northern Minnesota Sunday. This area of rain will likely just graze southeast Manitoba Sunday with some rain likely towards the US and Ontario borders. Sunday will also see increasing northerly winds over southern Manitoba which will draw in colder air through the day as temperatures fall into the single digits. In fact, there's a chance that rain may change to snow on the backside of this storm system Sunday night over northwest Ontario. Near to below normal temperatures are likely through the upcoming week over southern Manitoba.

100 years ago tonight.. Titanic sinks on a clear cold night in the North Atlantic

It happened a long time ago a long way from Manitoba, but on the 100th anniversary of the most famous maritime disaster in history, I thought I'd post some information about the weather the night the mighty Titanic hit an iceberg and sank in the cold calm waters of the North Atlantic 100 years ago tonight April 14-15, 1912. It's a compelling story that has captivated mankind for a century, and continues to do so.

So what was the weather like on that fateful night? Well, in a word.. cold. A large area of high pressure had moved into the North Atlantic off the coast of Newfoundland that evening, bringing clear, cold and calm conditions the night of April 14th. (see weather map left showing high pressure area almost directly over the site of the Titanic sinking) Conditions in the hours leading up to the collision and sinking of Titanic are described in the final report of the British inquiry, based on testimony by Second Officer Charles Lightoller:

From 6 p.m. onwards to the time of the collision the weather was perfectly clear and fine. There was no moon, the stars were out, and there was not a cloud in the sky. There was, however, a drop in temperature of 10 deg. in slightly less than two hours, and by about 7.30 p.m. the temperature was 33 deg. F., and it eventually fell to 32 deg. F.

The Titanic, speeding westward at a brisk 22 knots towards New York City, had been warned by several ships that day about large quantities of ice that lay ahead in Titanic's path. Captain Edward J. Smith, on his last voyage before retirement, altered course slightly southward to avoid the ice field.. but maintained a steady speed of 22 knots.. a puzzling decision on a dark moonless night in ice laden waters (perhaps overconfidence that lookouts could easily spot icebergs on a such a clear night?) The decision not to slow down proved fatal.. as the lookouts did not spot the iceberg in time for the speedy Titanic to avoid a collision at 11:40 pm April 14th 1912. Within 3 hours, the doomed ship had sunk to the bottom of the Atlantic, taking 1500 lives with her. The clear moonless night, together with a flat calm sea that prevented waves from breaking at the base of the iceberg (which would have made it easier to spot the ice a further distance away) gave Titanic's lookouts minimal time to spot a looming iceberg ahead. Had there been a moon that night, or a wind that would have created some waves to make the ice easier to spot ahead of time, the lookouts may have had more time to warn the Titanic's officers about the ice ahead, providing a greater chance to avoid a collision. But it wasn't meant to be.. all the factors came together that night, including the weather, to lead to the most famous and dramatic maritime disaster in modern history. (For more information on the conditions that fateful night 100 years ago, see the current Weatherwise article "Retrospect: Sinking of Titanic")

Wednesday, April 11, 2012

Nice Thursday on tap before some unsettled weather Friday.. no major warmups through next week

After a few cold days to start out the week, the weather will be turning milder Thursday with plenty of sunshine and temperatures rebounding into the mid teens. The nice weather will be short lived however as a frontal system moves in from the southwest, bringing clouds and some showers for late Thursday night into Friday. At this point, rainfall amounts look minimal with this system.. perhaps 5-10 mm or so, although locally higher amounts are possible with some embedded convection early Friday. This system will gradually pull out Saturday, with a trailing cold front bringing a return to near or below normal temperatures over the weekend into next week.

Sunday, April 08, 2012

Some below normal temperatures.. for a change..

Well, it's been awhile, but Winnipeg and southern Manitoba will be enduring a spell of below normal temperatures over the next few days, something we haven't experienced in a while. In fact, the last time Winnipeg saw more than 2 consecutive days below normal was back in late February when we had a stretch of 5 days that averaged below normal. Average highs in Winnipeg are now +8C and it looks like we'll be generally below that mark through mid week. Milder air is expected by Thursday with temperatures returning back into the mid teens. The good news is that conditions this week should be dry with no significant precipitation expected until later in the week into the weekend.

As I noted in a previous post.. the record breaking warm start to spring this March should not be viewed as a sign that the threat of cold weather is over for us. Of the past 9 warmest Marches in Winnipeg, all had some snow in April, and all were followed by a cooler than normal May.. suggesting an increased chance of a "backward spring" following a warm start.

Tuesday, April 03, 2012

Nice week ahead.. turning wet and colder for Easter weekend, snow possible for parts of western MB..

High pressure over the Prairies will provide a nice stretch of weather over southern MB over the next few days with sunshine and mild temperatures expected through Friday. Unfortunately, it doesn't look like the nice weather will hold through the upcoming Easter weekend as a storm system develops over the northern States and tracks along the international border. This system is expected to bring rain across southern MB Saturday and Saturday night which may turn to snow over western MB and higher elevations Saturday night into Sunday as colder air wraps into the system. It's still too early to say which areas will get the snow if any from this system, but at this point, travellers should be aware of the potential for a return to winter like conditions for Easter Sunday particularly towards the Saskatchewan border and higher elevations of western Manitoba.