Unsettled weather will be moving into southern MB for the holiday weekend.. especially Saturday into Saturday night when showers and thunderstorms with locally heavy rain are possible. The heaviest activity is expected west of the Red River valley overnight into Saturday where 25 to 40 mm of rain is possible with locally heavy thunderstorms. This activity will push east into the RRV by Saturday night. Drier weather is expected Sunday into Monday, before more showers move in Monday night into Tuesday.
The weekend outlook for Winnipeg and the RRV..
Saturday..Partly to mostly cloudy and breezy with a chance of showers or thunderstorms. Showers and thunderstorms over western MB spreading east into the valley by evening. High 24.
Saturday night..Showers and thunderstorms. Rainfall amounts 10-20 mm possible.
Sunday..A mix of sun and cloud. High 23.
Monday..Sunny at first then clouding over with showers developing Monday night. High 20.
Did you mean snow Rob, this is the May long weekend? LOLReplyDelete
Great job of letting us know what to expect in GfK this weekend, thanks.
Models have been all over the place with the timing and placement of precipitation expected over southern MB this weekend.. However, they have been fairly consistent in hinting at how things may evolve. The first batch of convection is expected to be warm frontal activity over the western Dakotas tonight, where there's the best setup with a strengthening low level jet and low level moisture advection. I suspect much of this activity will evolve into an area of showers and embedded thunderstorms that will push into southern SK and southwest MB Saturday morning, with areas of heavy rain. As the surface low moves east across the Dakotas, it will drag a cold frontal trough across ND with some additional showers and tstms firing up along this feature late Saturday into Saturday night, likely pushing into the southern RRV and SE MB. This activity will then push eastward into NW Ontario Sunday with a dry slot bringing drier air into southern MB. That's what the models are hinting at.. more precise details on timing and location of convection will require analysis of actual jets and moisture fields to see exactly how everything is lining up. But the potential is there for some stormy weather over the Northern Plains and southern MB tomorrow.. stay tuned.ReplyDelete
Yeah complex pattern for tomorrow as energy and precipitation from next system splits apart. Upper low will track way off to our west thru eastern Montana. As Rob said... first batch of convection looks to form on nose of LLJ around the disturbance and rotate back over Saskatchwan where it will devolve into stratiform rain anchored by trowal/ deformation zone.ReplyDelete
Meanwhile surface warm sector begins occluding out and brushes southern RRV and SE Manitoba. Strong moist and warm advection redevelops. Models like GFS are very progressive in pinching off warm sector and LLJ to our SE quickly while others are slower and further NW.
Yeah.. we will have to wait until tomorrow to see which scenario unfolds. If slower/ less progressive solution verifies then Winnipeg may still be under the gun for strong elevated storms and heavy rain as MCC evolves Saturday nite...
Been busy planning our aviation conference which is to be held next Tuesday.
Overall from what I see this evening...the main action tonight (Fri night) will spread out from the Black Hills toward Bismarck-Minot-Bottineau then up toward Brandon. I would not expect severe up our way. For Saturday night...wind fields are stronger in our area...and key seems to be how much front progresses and where does a weak low develop along the front. Models showing weak low somewhere vcnty of Fargo by 00z with boundary nr a Winnipeg to just west of Fargo line. Best 850 mb moisture/wind covergence in southeast ND or northeast SD and SPC SREF probablities highlight areas from just south of Grand Forks to Fargo then into eastern SD as highest threat for isold severe cells by 03z. Freezing levels quite high. Low level jet remains strong and should enable a complex to form and push into northwest MN overnight.
Hi Dan NWS GF!!!ReplyDelete
Long time no see!!
It will be interesting to see how this one play out!
Thanks for an update!
Look at all that convection that is firing up in the Dakota's tonight!ReplyDelete
I'm really getting pumped about our first thunderstorm outbreak of the season!!
I think Environment Canada might want to change the forecast for Portage La Prairie tonight!!!ReplyDelete
Showers and storms ending????
If anything it looks like that will be where the line of storms and showers will remain all night long!
Environment Canada discussion this morning ( FOCN45) states that supercell development is a possibility this evening in southern Manitoba!!!
SPC also still has a slight risk of storms for North Dakota!
What is your latest analysis of this storm potential????
Here's my "official" view of today over Southern MB:ReplyDelete
WITH MORNING RAIN AND
A CONTINUING SOUTHERLY FLOW AFTER THE PRECIPIATION MOVES OUT, SURFACE
DEWPOINTS WILL CLIMB TOWARD THE MID-TEENS THROUGH THE DAY TODAY
ACROSS SW MB AND THE RED RIVER VALLEY, PRODUCING MLCAPES OF 1500-2000
J/KG. SUBSTANTIAL WARM ADVECTION RESULTING IN 700MB TEMPERATURES OF
5-10C WILL PROVIDE A STRONG CAP TO SURFACE BASED CONVECTION THROUGH
MOST OF THE DAY. BY LATE AFTERNOON, A COLD FRONT WILL BEGIN TO WORK
ITS WAY ACROSS SW MB AND THROUGH THE RED RIVER VALLEY OVERNIGHT WHICH
WILL PROVIDE ADDITIONAL LIFT WHICH WILL LIKELY BE NEEDED TO DEVELOP
THUNDERSTORMS. THE MOST PROBABLE CONVECTIVE SCENARIO WILL BE LINEAR
MODE DEVELOPMENT AFTER 21Z WITH HAIL AND LOCALLY HEAVY RAIN BEING THE
MAIN THREATS. HOWEVER, WITH RELATIVELY SLOW EASTERLY MOVEMENT OF THE
FRONT COMBINED WITH A 50 KT LLJ, HIGH CAPES, AND FAVORABLE VEERING
SHEAR PROFILES, THE POTENTIAL OF SUPERCELL DEVELOPMENT WITH THE RISK
OF TORNADOES CANNOT BE RULED OUT (ESPECIALLY SHOULD THE STORMS BE
ABLE TO DEVELOP FROM SURFACE-BASED CONVECTION). THE HIGHEST RISK AREA
FOR THUNDERSTORMS WILL BE FROM THE SK/MB BORDER THROUGH THE RED RIVER
VALLEY, ALONG AND SOUTH OF THE TRANSCANADA HIGHWAY. TODAY'S DAY SHIFT
WILL DETERMINE WHETHER OR NOT SEVERE THUNDERSTORM WATCHES WILL BE
ISSUED. INDEPENDENT OF EITHER OUTCOME, AS THE EVENING PROGRESSES THE
STORMS WILL DEVELOP INTO AN EXTENSIVE MCS SUPPORTED BY THE LIFT OF
THE LOW LEVEL JET AND PROGRESS ACROSS THE RED RIVER VALLEY OVERNIGHT,
WHERE THE PRIMARY HAZARDS WILL RETURN TO BEING POTENTIALLY LARGE HAIL
AND LOCALLY HEAVY RAIN.
Brad (aka Buffalo Seven) pretty well sums it up. Cloud cover and warm mid level temps (cap) will delay things until late today into this evening, at which point the best chance for surface based convection will be in the axis of higher dewpoints and places that get some sun (with better clearing over ND today and areas near the US border) I think that will bring the greater threat of severe storms over the RRV and SE MB this evening and tonight, especially towards the ND border. As Brad mentioned, large hail and heavy rain will be the main threats, with the potential for some isolated tornadoes with discrete supercells that develop early before convection becomes linear.ReplyDelete
I'm not all that concerned about major tornado development now, as the surface dewpoints are pretty meager. The dewpoints aloft still have a ways to go, and the concern I would have is for elevated hailers tonight and if not, heavy rainfall. The fairly stable boundary layer after dark will preclude all but the most robust of storms from penetrating that stable layer with strong winds.ReplyDelete
Today should be interesting to see how far south the storms will form. It's truly a "tail-end Charlie" day.
I see Brandon's updated forecast at 11:00 has severe wording already!!!ReplyDelete
Looks like some very heavy rain is heading into that area!!!
Looking at the Satellite picture it would seem that Southern Manitoba might clear out this afternoon and at least get some solar!ReplyDelete
That would definitely set the stage for strong storms this evening!
A couple of issues:ReplyDelete
1) how far north will clearing get as warm mid-level temps surge north
2) When will the cap break down in N Dakota?
3)How fast will cold front and LLJ translate east..
GFS show does not show convective initiation in N Dakota until LLJ has moved SE of us. We would need an earlier break of the cap down there or LLJ will have be less progressive for Winnipeg to be affected by storms...
Tornadoes in Southern Manitoba? Not Likely. Huge warm nose on the prog soundings show greater potential for elevated supercells capable of decent sized hail late this evening into the overnight and we all know that elevated supercells do not produce tornadoes.ReplyDelete
Get your cameras ready for some nice lightning shots tonight!
Target area for tornadoes today will lie along I-90 in South Dakota...target...somewhere around...Murdo, SD.
Justin and Dave are you guys going to do some storm chasing today???ReplyDelete
Severe line of Tstorm developing from Minot to Canadian border on southern edge of stratiform precip shield.ReplyDelete
Will have to watch evolution of that line as trough moves east.. especially if clearing persists and high CAPE values can pool over RRV. Could be a very interesting day...
Severe storm looks to sneak into southern Manitoba just south of Boissevain. I'm quite surprised that there aren't any watches or warnings out, since the storm is under a severe thunderstorm warning in North Dakota.ReplyDelete
That storm from North Dakota heading into Southern Manitoba looks quite severe with a bow echo segments!ReplyDelete
Why is there no warning out on that cell North of Kilarney? It looks severe to me.ReplyDelete
KMBX radar shows 1" hail just West of Ninette.
Jon, I've been asking myself the same question. That storm must be producing wind gusts of 90km/h+ and at least nickel sized hail. Clouds tops are over 40,000 ft.ReplyDelete
That storm looks quite impressive from the national weather service radar out of Minot!
Large hail and strong winds are almost certain!
Just checked the national weather service radar and storm to the east of Brandon is starting to show signs of bowing out again!ReplyDelete
Damaging winds with this storm???
I believe so!!!
Agreed, Scott and Daniel. The cell is producing reflectivity values over 60 dBz (purple) on EC radar now, and is also showing 1-1.5" hail S. of Carberry from KMBX. I remain with my opinion that this cell is severe and is meeting severe criteria.ReplyDelete
Finally, a warning is out. EC is stating that loonie sized hail is possible...obviously that means it was capable of producing at least nickel sized hail for some time already. I wouldn't be surprised if strong winds were occurring as well, but hail is the main risk.ReplyDelete
The storm that's warned appears to be weakening on radar, but that may change... if there's a watch, it'll likely be for SW MB.ReplyDelete
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I have to echo previous comments... seems strange that EC would not even put out a watch for far SW Manitoba even after NWS Bismarck warned the storms as early as 1:20 PM ..coordination issue?ReplyDelete
Anyways.. will be interesting to watch the outflow boundaries from this convection as they interact with developing surface wave riding up along cold front. Outflow, triple point of devolping surface wave crest, southern edge of cap, and border of clearing all converge somewhere in the area between Minot and Bismarck in the east and Dickinson and Williston in the west.
Storms forming here would possibly consolidate into MCS and advect into RRV as LLJ gets better organized tonite. LLJ moves off quickly into NW Ontairo and Minnesota overnite but models show lots of QPF hang back west of surface front.. seems overdone as I would expect the complex to follow the main forcing off to the east, but we'll see.
Severe thunderstorm warning issuedReplyDelete
That storm is really moving along at a pretty good clip!
Things are starting to get going over SD. Another storm is also forming in extreme SW MB.ReplyDelete
Looking at the Woodlands radar I thought was a bunch of clutter looks to be some activity to the southwest of Winnipeg!
I'd keep an eye of this area for thunderstorm development!!
I have to agree with Daniel P, I thought the area to the SW of Winnipeg was just clutter, but now it appears to be an actual band of rain.ReplyDelete
And I'm correct. Severe thunderstorm watch out for SW Manitoba.ReplyDelete
Nice supercell with hook echo east of Mobridge SD.. tornado warned.ReplyDelete
I was on tornadovideos.net watching live streaming video of that large tornado that is on the ground in South Dakota!
Well I'm starting to notice where the line of storms will start!ReplyDelete
Looking at the broken line of storms to the west of Brandon, then around Minot and down toward Bismark! lifting to the Northeast!
Just have a peek at the Minot radar and you'll know what I mean!
Complex surface pressure pattern in place... low #1 is in Saskatchewan associated with main upper disturbance. Low #2 is in S Dakota and has warm front separting true tropical airmass from 'warm polar' air to the north. Low #3 is in NE Colorado and will become a key player tonite with models like RUC sending it up towards NW Minnesota or even far SE Manitoba by early tomorrow. Trough connects all three lows.ReplyDelete
Convection getting going in south central N Dakota on northern edge of 850 hPa theta e ridge and vicinity of triple point for second low. Low number three is progged to eject out of Colorado and race up the front slowing down its eastward progress (and LLJ). It will also drag warm sector of tropical air up across upper midwest. Models hit area of moisture convergence between back edge of LLJ and surface trough with most QPF.
Under this scenario, storms south of Bismarck should expand in coverage and move NE as the nite progresses... NW extent remains the question. At this point I suspect RRV/ Winnipeg will get brushed by possibly moderate rain with some embedded thunder.. best elevated instability and theta e ridge will remain south of the border (850 Td's in the upper teens!)
Severe Thunderstorm Watch issued for areas just south of the border.ReplyDelete
Severe thunderstorm watch issued for areas of North Dakota butting right up to the international border!ReplyDelete
All I can say is....
BRING ON THE STORMS!!!!!
Storms are now beginning to rapidly develop in North Dakota. My current thinking is that development will be a little further NW than the previous GEM-REG solution, however generalities seem okay. ND has significantly higher risk of severe weather from these storms; dynamics strong throughout both SRN MB and the northern plains, however thermodynamics are significantly more favorable south of the Intl. border.ReplyDelete
By the time the storms move into our area, expecting linear MCS with risk of hail and/or strong winds. Highest likelihood of severe WX should it occur will be south of the line created from Walhala, ND to Winkler, MB to Morden to Steinbach and out into the Whiteshell.
Ultimately, the lacking thermodynamics on our side of the border make watches unlikely.
In my opinion, I feel the SPC may have been a little aggressive in the westward extent of the severe thunderstorm watch in ND.
I see environment canada still indicates rain and storms beginning early evening for most areas. Getting a little outdated =Þ Need to push it a bit further I'm guessing.ReplyDelete
Thank you guys for all the updates today. =D I'm hoping to wake up to some storms tonight ! Would be my first storm of the year.!
Lightning is showing up a bit further west than expected; looks good that we may see some lightning tonight in Winnipeg :)ReplyDelete
GEM model overdid precip amounts with convection over southern MB yesterday.. only about 5 mm here in Winnipeg last night with some weakening thunderstorms. Yesterday's GEM was showing 30-50 mm over southern RRV and SE MB with that convective line, but it looks like a max of 15-25 mm in portions of the RRV last night. As expected, best convection was south of the border in the juicier air with some thunderstorms producing hail in eastern ND, and tornadoes in SD.ReplyDelete
Looks like a break in the precip today before next system threatens more showers and possible thunderstorms Monday into Monday night over southern MB. GEM again appears to be the most aggressive model with precip timing and amounts.. (overly sensitive convective scheme perhaps?)
Check out our blog for videos of yesterday's monster tornado in North Central South DakotaReplyDelete
Great stuff Justin.. awesome vids! That first one reminded me very much of Pipestone!ReplyDelete
So like Rob said, storm totals of 15-25mm worked out for portions of the RRV. Reported amounts surprisingly low for Winnipeg, given how hard it rained here for several hours overnight. Thunderstorms made it up through the whole RRV and into the interlake by the early morning hours. I saw several bolts of lightning from my view in downtown Winnipeg between 2 and 4 AM.ReplyDelete
EC's amended forecast amounts of 15-25mm or 20-30mm with local amounts of 40mm in thunderstorms worked very well through SE MB. Sprague was the only station that was straight under a thunderstorm, and they accumulated 38mm.
All in all a fairly interesting event (I was actually quite surprised by the showers this morning along the 500mb jet) and it'll be interesting to see how our event tomorrow night works out.
There definitely seems to some topographic or other factor favoring the set-up of the nocturnal, southerly LLJ from SE N Dakota into NW Ontario. This is the same region that also gets affected by edge of precip shield from Colorado Lows tracking across central plains. The result is farily sharp gradient in annual precip from SE to NW in recent years. A subtle shift north of these features would spell a large increase in precip for Winnipeg and points NW. We'll see what happens with this next system.ReplyDelete
SPC outlook for tomorrow is very similar to Saturday's with an elongated zone of "slight risk" of severe storms through the Dakotas. Set up is similar to Saturday's event, with warm frontal thunderstorms through the SD/ND border areas spreading north in the morning, then scattered severe storms developing along the dry line/cold front sweeping across the Dakotas by evening. Once aqain, best threat of severe storms will be south of the border in the juicier air where TDs in the teens to 20C are forecast to spread north, but some storms may track into far southern MB especially over the southern RRV and SE MB in the evening.ReplyDelete
Uncertainty in the evolution of the convective pattern is giving a wide range of model estimates of how much rain Winnipeg will see tomorrow. Toady's GEM and GFS show about 20-30 mm for Winnipeg, while the NAM grazes us with 5-10 mm. Ensembles give a good middle of the road estimates of about 10-20 mm.
Those strong winds sure did make into Western Manitoba this afternoon!!
As for tomorrow I'll looking forward to ROUND 2 of thunderstorms!
Take a peek at the latest GFS run!!!
Southern Manitoba looks to be hit with some very heavy convection tomorrow night riding up from the Dakotas
Shower at times heavy tonight according to Environment Canada!ReplyDelete
Look that first batch of storms will weaken but a major resurgence of storms late this afternoon!
Get your camera ready for a good light show!