Sunday, September 21, 2008
Nice end to summer.. unsettled start to fall
It was a beautiful end to summer over southern MB with sunny skies, balmy southeast breezes and temperatures in the 25C range. Fall officially arrives Monday morning at 10:44 am, and will be greeted with some unsettled weather in the form of showers and possible thunderstorms. The unsettled weather will come in two waves. The first wave of precipitation is expected overnight as a band of showers and scattered thunderstorms over North Dakota moves northward into the Red River valley. These showers may bring 5 to 15 mm of rain to Winnipeg overnight, although heavier amounts of 25-35 mm are possible in thunderstorm activity over portions of southern MB by early Monday morning. There should be a break in the shower activity through midday Monday which will allow temperatures to warm into the 20s along with dewpoints in the midteens. This will set the stage for another round of showers and thunderstorms to develop by late afternoon over southern MB ahead of a cold front. This line of activity may be accompanied by severe thunderstorms late Monday into Monday evening with heavy downpours (giving local rainfall amounts of 30-50 mm), strong winds, and possibly large hail. There may even be the threat of isolated tornadoes with some supercell storms early in the evening. Stay tuned as Mother Nature may be ushering in fall on a stormy note.
Posted by rob at 8:14 PM
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Are the showers and thunderstorms that are arriving tonight based on the warm front??
Or is that the stationary front that has been overhead the last couple of days???
Those overnight showers have left an extensive layer of low cloud across Southern MB this morning, extending all the way into northeast ND. That will limit the amount of daytime heating today needed to fire up those thunderstorms over us. However, there is a good area of clear skies through central ND from Bismarck to Devil's Lake area which may be the trigger zone for thunderstorm initiation later today where dynamics continue to be impressive for this late in the year. This area of thunderstorms will continue to develop rapidly northeastward, with models hinting at a possible squall line of heavy storms moving into the Pilot Mound-Portage areas this evening. Stay tuned..ReplyDelete
I see that Winnipeg updated forecast as of 11:00 AM calls for a few showers or Thunderstorms!
Meanwhile Portage La Prairie forecast calls for a few shower or thunderstorms with LOCAL amounts of 40 mm!!
Is there any chance of that heavy rain to shift into the Winnipeg area
If thunderstorms fire up to our southwest, then there's a good chance that this activity will roll through the Red River valley including Winnipeg tonight with some heavy downpours. New model guidance is suggesting that the heaviest axis of rain will be over the RRV tonight.. but we'll have to see where convection initiates this afternoon and evening to get a better idea of the heavy rain threat. But no doubt the potential is there.. dewpoints are quite impressive today in the RRV.. up to 18C now!.. which is getting unusually high for this time of year. This will support the threat of severe storms along with heavy rain.ReplyDelete
Looks like a flash flood watch has been issued be the national weather service for areas in north Dakota!ReplyDelete
I wonder if there will be a rainfall warning for Manitoba??
The rain is already starting to form!
Any severe thunderstorm threat that there was is pretty much gone!ReplyDelete
There are some thunderstorms embedded in the heavy rain!
The really heavy rain is coming already at the Manitoba border!
Looks like some pockets of 15 mm per hour rain is heading into the Portage La Prairie area!
as of the 6:50 pm radar image, there are barely any specs of yellow.ReplyDelete
i'd say that the severe storm threat has diminished at this point.
Severe Thunderstorm Watch issued for the Grand Forks area, all the way to the international border.ReplyDelete
I think the severe weather threat isn't gone yet for the RRV. There are still strong storms forming in Eastern ND.
I now agree!ReplyDelete
I see some wicked storms in North Dakota some south of Devils Lake
and some now just exploded north of Grand Forks!
Look out Scott!!!
Nice line of convection setting up from southeast of Devil's Lake to Winkler, MB with strongest cells in ND this evening. This line could set up as the heavy rain axis tonight, extending into the Red River valley and possibly Winnipeg, as cells train northeastward along the line much of the night. Local rainfall amounts of 30-50 mm possible in some areas along this axis by morning. Severe threat for hail and winds will diminish overnight, but support is there for severe cells into the early morning hours especially near and south of the border.ReplyDelete
Looks like the cell near Grafton poses the greatest risk/hope of hitting Steinbach. That cell South-East of Devil's Lake looks impressive.ReplyDelete
It's not over yet folks!
P.S. Where is the severe thunderstorm watch for the RRV? I assume it will be issued shortly...ReplyDelete
Maybe environment Canada is asleep at the controls.ReplyDelete
well if there is one issued it will most likely be issued East of Winnipeg!
You call it Daniel...ReplyDelete
Severe Thunderstorm Watch for SE MB.
Looks like SE Manitoba could be in for "training" of thunderstorms.ReplyDelete
Looks like Winnipeg will be right on the very edge of this heavy rain shield!!
2 minutes after I severe-warned it, Emerson gusted to 106. Phew.ReplyDelete
Close call Dave!
I see on the national weather service radar from Grand Forks that the storm actually "curled" out!!!
Was is some sort of "mini" gust front?????
It just goes to show--our RADAR wasn't showing too much, except for heavy rain, because the beam got attenuated by going through all that stuff. But the NWS one showed it at about the same time I warned.ReplyDelete
Time to extend the warning.
Gretna reported a wind gust to 165 km/h at 10:42 PM!!!ReplyDelete
Is that a gust front???
A thunderstorm that Collapsed???
Hold on to your hat !!!!!
That is the FIRST time that I ever heard Environment Canada use the wordsReplyDelete
"VERY DANGEROUS THUNDERSTORM"
Yeah I put that in because ... well, winds over 150 km/h can blow out windows.ReplyDelete
Looks like another line of severe storms is heading up from the border!ReplyDelete
If this line can somehow hold together then it might even clip Winnipeg with some heavy weather!
I can't believe my eyes....
a huge rain shield is heading in right behind that line of storms!
can anyone tell where the storms are now..i was in anola an left due due to the huge threat of wind gusts..not too mention the extreme lightning..this is very intense..any news would help as i am wondering if i should head back to anola????ReplyDelete
There is a line of heavy storms heading into the Emerson areaReplyDelete
heading due northeast!
Another batch of heavy rain and storms are going into the Winkler and Morden area!
Daniel: I kept the warning for around Emerson for exactly that reason--if nothing else, there'll likely be buckets of rain.ReplyDelete
Anon--you should be okay for Anola now. There's a lot of rain and thunder to come, but the main threat should now be heavy rains.
That is some incredible weather, especially for late September.ReplyDelete
I picked up 41.2mm early this morning from that MCS, as I will call it.