Tag: Above-Normal Temperatures

Beautiful Summer Weather Continues

Brad Leave a comment

The beautiful weather we’ve been enjoying over the Thanksgiving weekend is set to continue for a couple more days before slightly cooler weather moves in for the weekend. Fortunately, the dip in temperatures looks to be short-lived before warmer air once moves back into the region.

Wednesday
19°C / 9°C
Warm & windy; mostly cloudy

Thursday
17°C / 5°C
Becoming cloudy with showers in the afternoon

Friday
9°C / -1°C
Mainly cloudy & windy, clearing in the evening

Wednesday

Today will be marked with significant warmth hampered somewhat by the breezy southerly winds that will develop. An approaching low pressure system, responsible for spreading the above-average temperatures in Manitoba, will produce a strong pressure gradient over the Red River Valley today which will result in southerly winds increasing to around 40km/h by late this morning with gusts approaching 55–60km/h. These stronger winds will persist well into the evening before tapering off overnight.

Otherwise, it will be a fairly nice day. Temperatures will climb to around 19°C, with a very slight chance of eking out a 20°C for the day, and skies will be fairly mixed, probably trending towards the cloudier side of things. Skies will clear out a bit overnight as we head to a low of 9°C or so.

Thursday

Thursday will be perhaps an even nicer day than today will be. Skies will be a bit sunnier and temperatures nearly as warm – around 18°C for a high – but without today’s wind.

The NAM is generating quite a bit of shower activity across Southern Manitoba – shown here by this simulated RADAR image – on Thursday evening.
The NAM is generating quite a bit of shower activity across Southern Manitoba – shown here by this simulated RADAR image – on Thursday evening.

A low pressure system and associated cold front are poised to move through in the evening, however, which will bring with them some shower activity as the system swings across the Red River Valley. Northwesterly winds behind the cold front will begin tapping cooler air as we head to a low of 3°C overnight with showers possibly persisting through the overnight period.

If slightly heavier activity is maintained overnight, there’s a slight chance that the showers may change to mixed precipitation or flurries for a few hours, but no accumulation of snow would be expected. We’ll keep an eye on this system and provide updates in the comments below if necessary.

Friday

Friday will be a relatively unpleasant day, although in reality quite close to the normal conditions for this time of year. Gusty northwesterly winds to 30km/h and mainly cloudy skies will be the name of the game as our high sits 10°C cooler than Wednesday or Thursday at around 9°C. Little in the way of precipitation is expected.

Winds should taper off Friday evening alongside clearing skies as we head to an overnight low just below freezing.

The Weekend

Conditions will gradually improve through the weekend. Highs both days will climb somewhere in the 10–12°C range with relatively light winds. Sunday appears to be the more interesting of the two days as some showers push into Western Manitoba. It’s unlikely that any rain will make it into the Red River Valley, but we’ll certainly see some cloud from the system as it moves through.

The NAEFS is forecasting above normal temperatures next week.
The NAEFS is forecasting above normal temperatures next week.

The passage of Sunday’s system will mark the return of warmer air to our region and, at this point, it looks like we’ll be returning to above-normal temperatures for next week. Medium-range forecast models, such as the NAEFS, all show a strong signal of above-normal temperatures returning for the last week and a half of October.

Mild Weather Moderating; Rain Returns Sunday

Brad Leave a comment

Temperatures will remain well above normal for two more days before seasonal air begins pushing back into the province through the weekend as a cold front gradually progresses southeastwards. A chance for showers returns to southern Manitoba on Sunday as a disturbance developing in North Dakota causes the cold front to stall out over our area.

Friday
28°C / 16°C
Fog patches in the morning, then hot and humid

Saturday
26°C / 12°C
Chance of morning fog, then mainly sunny and warm

Sunday
⇘ 10°C / 6°C
Cloudy with rain likely

First the good news: after we burn off a little fog that developed overnight, today will be another beautiful, summer-like day with highs in the upper 20’s and surprisingly humid conditions for late September. Strong southerly winds at 40–50km/h with gusts as high as 70km/h will be tapping into a pool of moisture in the Northern Plains and drawing it northwards. Dewpoint values will sit near 17–19°C through much of the southern portions of the province.

Today will bring abnormally high late-September humidity to Southern Mantioba.
Today will bring abnormally high late-September humidity to Southern Mantioba.

Yesterday I erroneously tweeted that our dewpoint of 17.6°C broke the previous record of 16.8°C set in 2008 and that it had been the latest on record[1] such high humidity had been seen in Winnipeg. Rob’s Obs did a little digging and found that the actual record is still held by October 8, 1997 when the dewpoint climbed to 18.6°C. Whoops. I apologize for missing that.

That being said, today will give that record a run for its money; multiple models forecast our dewpoint to climb to 19°C, which if it happens would be the latest 19°C dewpoint on record.

Saturday will be a beautiful day in Winnipeg with a high in the mid–20’s and more comfortable humidity as a cold front gradually approaching begins flushing out some of the moisture in the region. There’s a chance of fog again in the morning and we may see a few clouds around, but the bulk of the day should be mainly sunny. Winds don’t look to be an issue.

This simulated RADAR image from the NAM shows a band of rain stretching across Southern Mantioba on Sunday afternoon.
This simulated RADAR image from the NAM shows a band of rain stretching across Southern Mantioba on Sunday afternoon.

Things change on Sunday as the cold front that was approaching on Saturday stalls out as a disturbance in North Dakota develops. A band of rain is expected to develop along the stalled out front, spreading from SW Manitoba eastwards through the afternoon until a band of rain stretches across the whole province. Temperatures will start off cool and only drop from there as the rain cools things off a little further and northerly winds at 20–30km/h continue to tap cooler air and bring it into the region. The rain should taper off late in the evening here in Winnipeg with anywhere from 5–15mm falling depending on the exact timing and speed of the system. Temperatures will dip down to around 6°C.

Unsettled Week Ahead Leading to A Cold Snap

Long-range forecasts don’t look particularly great. The first couple days of the week look seasonal temperature-wise. A series of Colorado Lows look to develop mid-to-late week which will bring a chance for showers, but more significantly, begin drawing down much cooler air from the Arctic. The end of the week looks like it will end with an Arctic outbreak bringing another shot of below-normal temperatures and brisk northwesterly winds.

  1. Records for seasonal dewpoint values go start in 1953.  ↩

Fall Starts By Putting Summer to Shame

Brad Leave a comment

The first week of fall[1] will start off with weather that will seemingly put this summer to shame. Very warm weather is on the way with potentially record-breaking highs across Southern Manitoba on Thursday!

Wednesday
25°C / 14°C
Cloudy; clearing for a sunny afternoon

Thursday
31°C / 16°C
Mainly sunny; increasing humidity

Friday
30°C / 16°C
Mainly sunny & hot

A prominent upper-level ridge in place over the Prairies has pushed the polar jet stream far northwards and allowed warm air to spread into the Southern Prairies from the United States. As a result, significantly warmer than normal temperatures will continue through the remainder of the week in Winnipeg.

Today will start off fairly cloudy thanks to some stratus cloud that spread northwards ahead of a dissipating trough of low pressure. The cloud should clear out for the afternoon and we’ll see temperatures climb to around 24 or 25°C. The temperature will dip to around 14°C tonight under mainly clear skies.

Thursday and Friday will both bring highs just at or over the 30°C mark under mainly sunny skies. South to southeasterly winds will begin tapping into some moisture from the Central Plains of the US and we’ll see the humidity gradually rise for the latter half of the week. Dewpoint values will climb into the mid-to-upper teens, which when combined with highs near 30°C, it will feel more like the mid-to-upper 30’s. The overnight lows both nights will be in the mid-teens.

Record-Breaking Potential

We have a slight chance of breaking daily record high temperatures on both Thursday and Friday. For Thursday, September 25th the daily record high temperature is 31.1°C set in 1950. For Friday, September 26th the daily record high temperature is 31.7°C set in 1957. Both days will see temperatures climbing to or just above the 30°C mark, and if maximum heating is realized, we may get the bump we need to break one of these records!

Date High Temperature (2014) Record High
September 25 27.7°C 31.1°C (1950)
September 26 30°C (Forecast) 31.7°C (1952)

Cooler Weekend

The weekend is looking great, despite a cool-down that’s in store. Daytime highs will dip around 5°C or so for the weekend with both days seeing highs in the mid–20’s. Fortunately this still puts us around 8°C above normal for the time of year, so there will be little to complain about. We’ll likely see a bit more cloud that we do through the second half of the week, but all in all it will be a gorgeous weekend!

  1. …sort of. Meteorological fall started at the beginning of September, but fall as most people consider it began on September 22nd after the autumnal equinox.  ↩

Summer Arrives!

Brad Leave a comment

Southern Manitoba is set to bathe in summer-time warmth as temperatures soar well above normal.

A broad upper-level trough developing over the Rocky Mountains will combine with a strengthened sub-tropical ridge over the southeastern United States to produce a southerly flow that will bring substantially warmer air to our region. As well as the warmer temperatures, humidity will become more noticeable heading into the weekend as higher dew point temperatures are advected northwards into the region. With the warmer weather will also come the potential for some shower or thunderstorm activity across much of Southern Manitoba.

Friday
25°C / 16°C
Mainly sunny. A little breezy.

Saturday
30°C / 17°C
Cloudy periods with a slight chance of showers or thundershowers. Windy and warm.

Sunday
24°C / 14°C
Chance of a morning shower or thunderstorm.

Friday

Today will be a very pleasant day. Under a mainly sunny sky, the temperature will climb to near 25°C as a southerly wind at 20-30km/h provides just enough of a breeze to keep things comfortable. The humidity will be more prominent than it’s been so far this year, but it will still be quite comfortable with dew point values climbing to around 15°C.

Heading into the night, temperatures will drop to about 16°C with variable cloudiness through the overnight hours with a slight chance of some shower .

Saturday

Tomorrow will start with a fair amount of mid-level instability riding ahead a warm front pushing eastwards. This will present itself with a slight risk for showers or thunderstorms through the early morning. Afterwards, we’ll see cloudy periods with fairly windy conditions with a southerly wind at around 30-40km/h. Very warm air will work in aloft, driving our daytime high up to 29 or 30°C. In addition to the warmer air, the southerly winds will also advect more humid air northward with the dew point climbing towards 17 or 18°C which will start to make it feel a little sticky outside.

Temperatures of 30°C or greater (dark green) are expected across much of Manitoba on Saturday.
Temperatures of 30°C or greater (dark green) are expected across much of Manitoba on Saturday.

As everything heats up, there will be a potential for thunderstorms, but there will be little in the way of a threat for severe storms. If we quickly look at the ingredients required for thunderstorms:

  • Moisture: Dew points will climb into the mid-to-upper teens, through a suitably deep layer, and be supportive of storm generation. The dew points are on the low side for the atmospheric thermal profile which will result in relatively high-based storms.
  • Instability: Deep instability will be present. Mid-levels are fairly unstable, and low-levels will destabilize fairly dramatically by mid-afternoon thanks to intense surface heating driving temperatures towards 30°C.
  • Shear: This is where things fall apart. While the low-level winds will provide favourable inflow into the storm bases, winds will be very slack through the mid-levels. This will dramatically impact the ability for storms to organize and will limit their potential growth.
  • Trigger: Triggers for storm generation look fairly weak. The synoptic triggers look to remain outside our region; the warm front will be in Central Manitoba, the cold front will be hanging back through Central Saskatchewan and the main warm sector trough also will trail back into southeastern Saskatchewan. The intense surface heating will likely produce many mesoscale triggers, especially along significant terrain such as the western escarpment of the Red River Valley and the Riding Mountains.

As a result, we’ll see the potential through much of Southern Manitoba for thunderstorms, however they’ll likely be short-lived, high based storms whose main threat will be strong winds or large hail.

It’s likely that rain with embedded thunderstorms will develop in North Dakota on Saturday night and lift northeastwards into Southern Manitoba, bringing the risk of rain and thunderstorms to somewhere in Southern Manitoba through the overnight period into Sunday morning. The areas that will see the risk will depend highly on exactly where the precipitation develops in North Dakota.

Temperatures will remain quite mild Saturday night with the overnight low bottoming out at only around 17°C.

Sunday

Sunday will be the most organized day for precipitation of the weekend. The system bringing the warmer air to the province will push off to the East through the day, dragging a cold front across the province. Widespread showers and thundershowers will be associated with the cold front as it pushes eastwards, and as a result showery weather is likely. It’s a little early for too much detail, but it seems like the chance for precipitation will start around mid-to-late morning and taper off by late afternoon.

The temperature will climb to around 23 or 24°C before the cold front swings through. Things will clear up by Sunday evening and we’ll see a beautiful night with a low near 14°C.

UPDATE: An updated look at Sunday’s weather is available in the comments section below.

Next Week

Next week looks to continue the warmth with highs in the mid-20’s, but by mid-week it looks like unsettled weather will return to Southern Manitoba and bring multiple days with chances for showers or thunderstorms. It seems like we’ll lock into seasonal to above seasonal temperatures, so get out and enjoy the summer weather that we’ve all waited so long to see!