Get Ready for crazy cold weather! A pattern shift is on the way !

Southern Manitoba has been relatively lucky over the past few months in regards to extreme cold . However as we are now in the First week of December it’s not a surprise that we will be seeing a shift to colder than normal weather conditions. A clipper system will be the culprit of this pattern change. If we Manitobans have managed to handle a blizzard then I’m sure we can handle a bit of cold weather. We’re Canadians after all.

A area of high pressure will dive south into Manitoba and drop our temperatures as a large swath of arctic air builds southwards . EEK.

Southern Manitoba will experience relatively seasonal temperatures on Saturday with high temperatures in the mid minus single digits with some areas reaching the 0 degree mark or  just slightly above zero. A clipper system will go through southern Manitoba on Saturday as well, with a chance of mixed precipitation in the morning hours, and early afternoon. Especially in the Southwest portion of Manitoba into the Red River Valley, there is a possibility of freezing drizzle mixing in as temperatures hover near the freezing mark. There is a higher likelihood for a few small localities in southwest Manitoba near Melita and Virden towards Killarney to get a quick few bursts of freezing drizzle. Justin or Me (Mike) will update you tomorrow morning on that. Behind the system winds will switch to the North and Northwest bringing in a gradual drop in temperatures overnight.

As the night progresses on Saturday a area of high pressure and a burst of arctic air and colder winds will drop temperatures overnight into the mid minus double digits , with windchills dropping into the minus 20s. Areas in the inter lakes will see temperatures drop even more into the low minus 20s. Areas as far north as Thompson will see temperatures between minus 21 and minus 30C. Windchills could exceed minus 35C.

As for Sunday winds will be light out of the NW temperatures will not recover much on Sunday as skies remain clear to partly cloudy as a low pressure system skirted to the south. High temperatures on Sunday will only get into the mid to high minus double digits. (-12 to -18C.)

On Sunday night it will be exceptionally cold with low temperatures exceeding minus 20 in the Red River Valley and inter lakes region. Further south and west you go temperatures will be more on the verge of surpassing minus 20 degrees in the high minus double digits. Windchills probably would be nearing minus 30 in a few locales. Areas south and west of Winnipeg on Sunday night might be a tad warmer.

To start the work week on Monday temperatures won’t recover much, with daytime highs still struggling to warm past minus 12C. As we get towards the middle to late week, there is a sign of a small moderation in temperatures, so temperatures will be in the lower minus double digits around -10 to -15 instead of -15 to -20C. We will update you through out the week in regards to any change in the pattern. I know I’m sure I’m not the only one that likes the cold either. -Mike McGregor

Severe weather threat to end the week

Southern Manitoba will be experiencing likely one more blast of severe weather to end the week, it's not going to be a complete washout as the sun will most likely come for the day before a trough will enter  southern half of Manitoba to allow for cooler more seasonable air to come into the province.

Southern Manitoba will experience one last blast of warm and humid air before a cooler more stable weather pattern takes hold. Let’s get down to the details. A trough of low pressure will enter southern Manitoba tonight bringing with it another severe weather threat for the province of Manitoba tomorrow. As I say this I am not a professional but a experienced weather specialist. This system will be supplying moisture from the gulf of Mexico allowing for dewpoints to climb into the high teens or low 20s tomorrow afternoon and temperatures from 24 to 27C making it feel closer to the mid 30s. With CAPE values potentially reaching 2,000 to 4,000 JKg tomorrow and lifted indices between -5 to -10 there will be the potential for moderate to explosive development and it should be enough to maintain storms when and if they do develop. A little more complicated but I'll try and explain it, looking at shear for storm maintenance and organization, it definitely isn't lacking. Supercell composite parameter is anywhere between  4-10 meaning, the highest in the red river valley, EHI of 2 to 7, Storm Relative Helicity of 200 to 400 around 10pm, and 20 to >60knots of Bulk Shear.. The trigger will be a cold front entering southern Manitoba with a trough in the jet stream as the front slices into the upper level ridge.

Based on model consensus I think that during the morning timeframe to afternoon there will be an area of storms trailing the warm front , that may end up missing the red river valley completely. They will pose a risk for heavy rainfall and small to moderate size hail. They should clear the North by the late  afternoon.  The areas further south in the warm sector may heat up substantially to allow for what looks like there may end up being a area of supercell development in the southwest portion of Manitoba into the red river valley , once these storms grow they may decide to travel in there own direction if there is not much in the way of organization but if they do choose to organize into a squall
 line the potential would exist for wind gusts in excess of 90 to 100km/h, hail to the size of toonies or golfballs. There would also be a concern for tornadoes IF there is enough clearing in the afternoon, based on EHI readings supercells could support weak to strong tornadoes. Once storms organize into a line I believe there will be a risk for flooding if storms train over the same area for a long time,  and
if those areas have been hit by multiple storms before the main batch in the evening. I’m concerned about the areas in the inter lake especially. Please keep an eye out for watches and warnings as the day progresses. We at Manitoba weather centre will keep you informed of any alerts. Once storms move through a cooler more stable airmass will take place for the weekend with temperatures closer to the normal of 14-17C, and overnight lows in the mid to high single digits.

Severe Weather Threat with Tornadoes Possible later today.

PASPC Convective Outlook :Severe Thunderstorms with a tornado or 2. Cannot be ruled out. 

Severe Thunderstorms and or Supercells around evening time in the Red River Valley

SOUTH-EASTERN MANITOBA WILL BE THE FOCUS FOR SEVERE THUNDERSTORM  DEVELOPMENT TODAY. AHEAD OF THE TROUGH, MODERATE SOUTHERLY WINDS OF  

30 TO 40 KM/H COMBINED WITH A CAPPING INVERSION WILL BUILD DEW POINTS  
INTO THE UPPER TEENS OR LOW 20S OVER THE REGION, WITH ADDITIONAL  
POOLING IN THE VICINITY OF THE TROUGH ITSELF. THE HUMID CONDITIONS  
COMBINED WITH MID-LEVEL LAPSE RATES NEAR 7C WILL COMBINE TO PRODUCE  
1500 TO 2000 J/KG OF MLCAPE. WIND PROFILES SHOW STRONG SPEED SHEAR  
WITH MODERATE LOW-LEVEL CURVATURE; BULK SHEAR VALUES WILL BE CLOSE TO  
50 KT WHILE SRH VALUES ARE FORECAST TO CLIMB ABOVE 200 M/S. ALL  
THIS WILL COMBINE TO PRODUCE A MODERATE SEVERE THUNDERSTORM THREAT  
OVER THE REGION.  
  
THUNDERSTORMS WILL LIKELY DEVELOP ALONG THE TROUGH LINE LATE THIS  
AFTERNOON (SOMETIME AFTER 22Z) WHILE IT LIES OVER THE SOUTHERN  
INTERLAKE INTO WESTERN MANITOBA. THE TROUGH WILL LIKELY SUPPORT  
SEVERAL DISCRETE SUPERCELLS THROUGH THE FIRST COUPLE HOURS OF ITS  
LIFESPAN, THEN FILL OUT INTO A MORE SOLID LINE OF THUNDERSTORMS AS  
THE TROUGH PUSHES INTO THE SOUTHEASTERN CORNER OF THE PROVINCE. THE  
PRIMARY THREAT FROM THESE THUNDERSTORMS WILL BE LARGE HAIL GIVEN THE  
HIGH CAPE VALUES AND FAVOURABLE SHEAR. ANY THUNDERSTORMS THAT ARE  
ABLE TO ORGANIZE A SUPERCELLULAR STRUCTURE WILL ALSO BE ABLE TO  
PRODUCE DAMAGING WIND GUSTS IN EXCESS OF 90 KM/H. ADDITIONALLY, THE  
STRONG INFLOW, HIGH DEW POINTS AND RESULTANT LOW LCLS, AND LOW-LEVEL  
HODOGRAPH CURVATURE ALSO PRESENT A LOW TORNADO THREAT. SEVERE  
THUNDERSTORM WATCHES AND/OR TORNADO WATCHES WILL BE ISSUED LATER THIS  
AFTERNOON AS REQUIRED.  
  
THE GREATEST UNCERTAINTY WITH THIS SYSTEM IS HOW EXTENSIVE  
THUNDERSTORM DEVELOPMENT MAY BE; AT THE MOMENT THE IDEAS THAT THERE  
COULD BE JUST A FEW ISOLATED SUPERCELLS OR THAT IT COULD GROW INTO A  
SOLID LINE OF THUNDERSTORMS ARE EQUALLY BELIEVABLE AND FORECAST  
MODELS SHOW THAT, OFFERING A DIVERSE SELECTION OF OPTIONS. IT WILL  
LIKELY DEPEND ON SUBTLE BALANCES BETWEEN THE LOW-LEVEL INFLOW AND  
MID-LEVEL WINDS AND PRECISELY HOW MUCH THE LOW-LEVEL FLOW BACKS OR  
VEERS AHEAD OF THE TROUGH.  
  
THE THUNDERSTORMS WILL EXIT MANITOBA LATER THIS EVENING. MORE SETTLED  
CONDITIONS ARE EXPECTED ON FRIDAY.  

Information from Environment Canada. Didn't have time to create a post of my own. 

https://kamala.cod.edu/offs/CWWG/1907111900.focn45.html

  aytime heating, MLCAPE will reach 2000 to 3000 J/kg. The approach of a midlevel speed maximum will increase the bulk shear to 40-50 knots. As a result, supercells are expected during the mid to late afternoon, with the main threats being large hail andThe A low pressure system is forecast to move through central Manitoba, with a surface trough expected to extend to its southwest. South of this system and ahead of the trough, moisture will increase, peaking with dewpoints around 20 C. Coupled with daytime heating, MLCAPE will reach 2000 to 3000 J/kg. The approach of a midlevel speed maximum will increase the bulk shear to 40-50 knots. As a result, supercells are expected during the mid to late afternoon, with the main threats being large hail and damaging winds. The tornado risk will be minimal, as surface winds will be somewhat veered. As the evening wears on, storms are expected to congeal into a broken line and move off to the southeast, out of the region.

Severe Weather possible for southern Manitoba, this evening.

Much of southern Manitoba is at risk for severe weather late this afternoon into this evening.

Southern Manitoba will be under the influence of a southerly flow today with temperatures reaching into the mid to high 20's with humidex values near and around 38 to 42C. An approaching trough and cold front to the west of our area will encounter the warm and humid airmass that is in place allowing a potential for powerful storms to occur. Let's have a look at the data.

Moisture: Dewpoints will be in the 18 to 21C range, for the most part with a chance for a few areas to have dewpoints about near 25C. Ample moisture will be in place. The question is the capping, because the moisture and heat may rise high enough in mid levels to prevent storms from forming. The cold front may or may not be sufficent to allow for enough cooling to occur at mid levels. And allow the cap to break.

Shear: Definitely not lacking at all, EHI values of 3 to 5 and Helicity mainly the highest west of Winnipeg into the Red River Valley around 8pmish 300 to 500 m2/s-2. Supercelluar structure is definitely possible, and or high winds. Sufficient enough for storm organization.

Instability: Sufficient instability will be in place for southern Manitoba this afternoon/evening, mlcapes and SBCapea will be on the order of 3,000 to near 5,000. With Lifted indices on the order of -7 to -10.

Trigger: The cold front will be coming in from southeastern Saskatchewan and moving into southwestern Manitoba over the next few hours into the Red River Valley area by the evening. Should provide focus for convective development as well as possible supercells.


The environment in place will end up resulting in severe thunderstorm/supercells formation somewhere between Brandon and the area east of Winnipeg, all depending on the timing of storms firing. If Storms do manage to form there will be a chance for discrete supercells to occur and pose a tornado threat. There is around 1 million or so people in that risk area for tornadic development, including Brandon and Winnipeg. There is a risk for hail up to golfball and or baseball size hail to occur, Once storms organize later on this evening the threat for damaging winds could be present with an ongoing large hail threat (up to baseball size hail), wind threat for winds over 100km/h, rainfall potential up to 50mm or more, and frequent dangerous lightning. Storm threat should ease up somewhat as storms travel into Northwest Ontario or southeastern Manitoba depending on where they form.

I will keep you updated as the evening goes on. -Mike

Severe Thunderstorms likely this evening into the overnight.

Good evening, everyone Mike here. Southern Manitoba looks like it may have one of the first severe weather events of the year this evening as we head into the overnight, a trough of low pressure this evening into the overnight will encounter a  hot and humid airmass in place this evening. This will allow for cooler and more stable conditions to come in play for the rest of the weekend.

A cold front crossing the province this evening into the overnight and morning, will be able to create the potential for severe thunderstorms. Looking at the data I have compiled there is sufficient ingredients available for severe weather to occur in our area, that could last well through the night. Let's use the MIST principle from A Weather Moment.

Moisture: A steady stream of gulf moisture will continue filling in to the area of the Red River Valley into Southeastern Manitoba with dewpoints (a good measure of what the humidity levels are like in the atmosphere, the closer the dew point is to the actual temperature the more likely it feels like a sauna in the summer under hot conditions. In the spring/fall it'll feel more like someone watered your lawn.) averaging between 15 to 20C, there will be no shortage of humidity which will allow the humidex values to peak to about 35 to 42C in areas.

Instability: With sufficient surface heating which occurred today and continues this evening, Instability in general is enough to fire severe thunderstorms. CAPEs will be on the order of 1,500 to 2,500 J/kg, less as the night goes on. Lifted indicies will also be between -2 and -8 at the max.

Shear: Bulk Shear of 20 to 50 knots and EHI values of 1 to 3 will be enough to support storm organization all based on current HRRR data and Data from the RDPS.

Trigger: Will be a cold front stalling out to the west of the Red River Valley and it moving east overnight, and an arrival of a frontal disturbance coming up from Montana and Wyoming overnight.

The photo I used above highlights the threat of severe weather for the area for the evening into tomorrow in Southern Manitoba. I only filled in the map with the lines, versus filling it in with colour so when looking at it your able to see better. In conclusion expect a line of discrete supercells or severe thunderstorms to form west of Winnipeg between 6 to 9pm and travel east northeast with additional storms likely heading into the late evening period. The main risks will be wind gusts over 1000km/h, hail up to the size of quarters, ping pong balls, or  golf balls, Heavy rain in excess of 50mm, frequent and dangerous lightning, and a very small risk of tornadoes. The risk of tornadoes is a 5 to 10% chance, low risk. U

The storms we get overnight will likely travel along the Red River Valley or a bit to the southeast of the valley depending on how things go with the setup. Justin and I will update you as things progress. The storms overnight might be a little less severe as heating from the day is diminished, the good news though is that we will get the needed moisture for this area of the province. A chance for thunderstorms redevelop tomorrow afternoon although non severe with a few sub severe cells possible.  A note a severe thunderstorm watch is in place for Winnipeg and the Red River Valley including parts of Westman. Full details here, for updates: https://weather.gc.ca/warnings/index_e.html?prov=mb

I look forward to tracking the storms with you all, this evening. Stay safe! Pray we get a good rain, God bless- Mike

Colorado low to continue to affect Southern Manitoba until Tuesday.

Southern Manitoba is expected to be impacted by a Colorado low overnight tonight into early Tuesday, light snow and deteriorating conditions are already occurring with reports of highways being snow covered with blowing snow and poor visibilities. No highways have been closed as of yet, however closures may result as snow accumulates and roadways start becoming difficult and dangerous for travel especially with blowing snow, and poor visibility. 

                                        

                                     

Snow impacting much of Southern Manitoba, as moisture streams in from the south, (from Rain Viewer IOS at 10:05pm)

Snowfall warnings are in place for a wide swath of southern Manitoba including the city of Winnipeg, city of Morden, city of Winkler, city of Steinbach and the city of Brandon.

Current thinking is that most areas running from south of the Trans Canada Highway especially from the USA Border towards the corridor of Highway 2 could pick up as much as 15 to 25+cm, areas running from the Trans Canada highway from Elkhorn to just south of Whitemouth including Winnipeg and Brandon could 10-20cm. From the parklands by Russell into the inter lakes, and eastern Manitoba by Bissett could get 5-10cm. Areas by the lakes will get a Trace to 5cm. Keep in mind the snow we get will be light and fluffy, as temperatures remain too cold to hold a lot of moisture in the snow, not a lot of water content in the snow. So it’ll be easier to shovel. Current Guidance suggests that this system will have some brisk northerly winds to about 15 to 30km/h gusting to 50km/h at times. Highway travel will be rough, that is why me and Justin will be posting highway travel updates. I wouldn’t suggest any one travel, but if you are going to please don’t forget to bring your travel kit with you, or youll end up becoming like the abominable snow man while you look for help. 😂😂😂 No one wants to end up seeing you covered in snow with your eyebrows frozen and face snow covered, you may end up causing an accident and both of you may end up becoming like the abominable snow man and stranded for good. 😂😂 Once this system clears out on Tuesday evening we should end up getting light snow behind the system. There will be cold north winds coming in behind this system , windchill values will go from being at minus 20 on Monday into the minus 30s and minus 40’s for the middle of the week into the weekend.



Stay tuned for updates on Manitoba Weather Center with me and Justin.