Seasonal & Unsettled Weather Ahead

Brad Leave a comment

The cold weather evidenced by a temperature that dipped down to a very chilly –3.8°C at the Winnipeg Airport on Tuesday morning has quickly been replaced by more seasonal conditions which will persist through the remainder of the week. Sunshine will be a bit harder to find, though, with plenty of cloud and unsettled weather in place as low pressure system stalls out over Southern Manitoba.

Today will start off fairly pleasant with temperatures in the 8–10°C range and partly cloudy skies. The cloud will only increase as the day progresses, however, ahead of an approaching low pressure system. As the low gets closer, winds will strengthen out of the south to 30–40km/h, with some gustiness on top of that, while the temperature climbs towards our daytime high of 17°C.

Scattered showers will develop through the afternoon and become more widespread heading into the evening. There’s a very outside chance of a thunderstorm, but the risk is quite isolated and something along the lines of isolated moderate to heavy showers activity is more likely. Rainfall amounts overnight will vary widely with anywhere from 2–10mm generally expected, however localized patches of more or less are possible. Winds will continue out of the south to southeast at 30–40km/h overnight with a low near 11°C.

GDPS 12hr. QPF valid 00Z Friday October 02, 2015
One shot in the dark at rainfall totals across Southern Manitoba through the day on Thursday.

Thursday will see the showers gradually taper off through the day as temperatures climb to around 15°C with breezy south-easterlies continuing at 30–40km/h. Skies will remain fairly cloudy through the day and into the overnight hours. Some clearing will work its way into the Red River Valley from the east overnight as temperatures dip to around 7°C.

Friday will finally bring clearing skies and slightly warmer temperatures as the cloud pushes off to our west. Winds will remain fairly breezy at 30–40km/h for much of the day before tapering off towards evening hours. Temperatures will climb into the upper teens for daytime highs through the Red River Valley and dip down to a chilly 5°C or on Friday night.

Pleasant Weekend Ahead

All things considered, this weekend will be quite pleasant. Just a few clouds are expected to be around with daytime highs in the mid-teens & less windy conditions than we’ll have rounding out the work week.

First Risk of Frost This Year

Scott Leave a comment

Most of southern Manitoba will be at risk tonight as the potential for the first frost of the fall looms.

There will be a risk of frost in southern Manitoba on Tuesday morning
There will be a risk of frost in southern Manitoba on Tuesday morning

Monday

Today will feature mainly sunny, but cool conditions. A surface ridge of high pressure will bring about chillier weather in southern Manitoba, with daytime highs only in the low teens. The wind won’t make it feel any warmer, with speeds of 30km/h out of the north-west.

Skies will remain mainly clear overnight into Tuesday, allowing temperatures to drop near the freezing mark. Low-lying areas are very likely to receive frost on Monday night. Elsewhere, frost will be more spotty, but the outer edges of Winnipeg will be at risk, with the downtown area likely staying above freezing.

Tuesday

After we warm up from near freezing temperatures on Tuesday morning, the rest of the day will be rather pleasant. Temperatures will climb into the mid teens under mainly sunny skies and light winds. Overall, it will be a fairly typical late September day.

Wednesday

Wednesday looks to be the warmest day in the first part of the week, with temperatures in the mid to upper teens. The wind will be gusty from the south or south-east though, making it less pleasant than it would otherwise be. Skies will range from a mixture of sun and cloud to mainly cloudy.

Above Average Western Pacific Typhoon Season Continues to Produce

Matthieu Leave a comment

Typhoon Dujuan formed earlier this week on Wednesday in the middle of the Pacific Ocean and continues to barrel westward toward northern Taiwan and the eastern shores of China.

[map type=”terrain” autofit=”1″ disable_scrollwheel=”1″] [pin]Taipei[/pin] [pin]Wenzhou[/pin] [/map]

The Western Pacific typhoon season, which is running above average this year with already 21 named storms, has primarily affected Japan, China, and the Philippines. The average number of named storms for a full season averages around 25 storms (May until late October is peak Western Pacific storm season, but storms can form outside this period). Dujuan currently sits about 1200km east of Taiwan shores and is still undergoing intensification. As of Friday night the storm had sustained winds of 167km/h, gusting up to 200km/h and had an estimated central pressure of 960mb. The Japan Meteorological Agency forecasts that by the end of the weekend it will have intensified to a high end category four equivalent storm as it approaches Taiwan. With sea surface temperatures in the order of 30°C and shear values between 5-10kt their forecasts for a powerful typhoon is warranted.

Infrared satellite imagery of Dujuan on Friday night shows very cold tops on the south side of the eyewall and an eye that has cleared out nicely. (Source: UW-CIMSS)
Infrared satellite imagery of Dujuan on Friday night shows very cold tops on the south side of the eyewall and an eye that has cleared out nicely. (Source: UW-CIMSS)

Latest 00z forecast models on Friday night had the storm brushing northern Taiwan and then pushing onto China’s mainland by Monday night near the city of Wenzhou. With a track like this, northern Taiwan would take the brunt of the storm with severe storm surge, high winds and heavy rain, while the threat to China wouldn’t beas major they would still see extremely heavy rainfall with the remnants. However, it must be noted that there is much uncertainty about the specific track still and the storm could deviate from current model forecasts.

Only one of the numerous forecast models' output for Dujuan. This one from the 25/12z ECMWF - brings the storm down to 935mb near northern Taiwan. (Source: Wunderground)
Only one of the numerous forecast models’ output for Dujuan. This one from the 25/12z ECMWF – brings the storm down to 935mb near northern Taiwan. (Source: Wunderground)

Warm & Windy Weather Ahead

Brad Leave a comment

A beautiful end of week is on tap as temperature soar well above seasonal values with plenty of sunshine on tap. Things will take a slight turn for the end of the weekend as a cold front slumps through the Red River Valley and ushers in a windy return to temperatures that are…just slightly above seasonal values.

Today and tomorrow will be gorgeous days with daytime highs in the mid-to-upper 20’s soaring more than 10°C above seasonal for this time of year. The wind will be fairly noticeable, however, increasing each day out of the south to around 30–40km/h, with some gustiness particularly on Saturday. Expect overnight lows in the low to mid-teens.

Forecast 850mb temperatures valid Sunday morning from the NAM.
Shown here in the NAM forecast for 850mb temperatures, a cold front will be advancing through Manitboba on Sunday morning.

A cold front will slump through the Red River Valley on Saturday night, shifting the winds to the northwest late overnight and bringing a slight chance of showers to the region. Overall, the frontal passage looks to be fairly dry with little precipitation expected.

This will lead to a breezy Sunday with a high that, while still above seasonal, will be quite a bit cooler than the prior couple days, likely settling near the 20°C mark. While the morning cloud will clear out, some variable cloudiness will likely develop as things warm up a bit in the afternoon, leading to a bit of a mixed sky through the day. The low temperature will dip into the mid-single digits on Sunday night.

Before that happens, though, we’ll have two beautiful late-September days to enjoy!