Monday, January 18, 2010
Winter storm system may affect parts of southern Manitoba by Sunday..
Long range models continue to show the possibility of a strong storm system developing over the central US plains moving into Minnesota by the end of the upcoming weekend. This storm system has the potential of bringing the first significant snowfall over southern MB since our Christmas storm, with heavier amounts possible over North Dakota and Minnesota. This system is still several days away and there is a lot of uncertainty on the track and strength of the storm, but the potential is there for a snowy end to the weekend over southern MB. Stay tuned..
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You can see it coming but aren't allowed to forecast it. How frustrating that must be!!!
ReplyDeleteInteresting scenario to unfold next several days with many different possible 'pathways' or outcomes.
ReplyDeleteWith very mild 850 hPa temps and souterly flow persisting for several days... potential exists for significant reduction of snowcover particularly north of int'l border. This is especially true if what I think I see in the models is correct.. peresitent warm moist advection in response to lead disturbacne will generate area of drizzle/light rain and fog with temps posibly above zero. The light precip will gradually spread NE and reach Winnipeg by late Thursday. Conditions like those would rapidly eat whats left of our snowcover.
Then attention turns to main low as enrgy consolidates and we'll have to watch where deformation zone and heavy snow will set up... hmm yeah it does sound familiar lol.
That cloud cover really doing its thing to keep our temperature up tonight.. currently -5C in Winnipeg under cloudy skies, but just down the road in Morris, it's clear and -16C! Cloud doesn't appear to be moving this evening, but we'll see if that light southerly wind clears us out overnight.
ReplyDeleteYeah patchy low clouds playing havoc with temp forecasts tonite...
ReplyDeleteRUC 925 hPa relative humidity field has so-so handle on the very low clouds/moisture. If anything it suggests a consolidation of higher RH south of us by dawn.. but like Rob pointed out any break would cause temps to tank and fog to develop.
Intrestingly, models show Winnipeg on the fringe of cloud cover on 850 hPa RH fields until Thursday but lower clouds/fog may persist... very tricky forecast in terms of temps and cloud cover.. general idea seems to be graudual warming and plenty of low clouds... we'll see.
Lots of freezing fog this morning making all the trees a night white!
ReplyDeleteNWS out of grand forks has already issued a special weather statement about the weekend storm!
Rob!
Any latest details on how it could affect southern Manitoba????
Models are starting to trend away from a storm in Manitoba. In fact, they have moved a significant amount of precip out of ND as well. We'll have to wait and see if this trend continues.
ReplyDeleteWhen does the sun get strong enough in these parts to stir up inversions? Or does it ever? I remember a June day with the sun shining brightly, not a breeze, and the temperature frozen in the mid-teens for hours.
ReplyDeleteThe 12Z glb run for 19 Jan puts most of the weekend storm south of MB, with the bulk of the pcpn falling in the Dakotas. Looks like liquid pcpn for lower elevations in SD with freezing pcpn / snow for ND. At this time, it looks like a near miss for Winnipeg...time will tell.
ReplyDeleteAs Dan mentioned, 12Z GLB takes storm well south of southern MB this weekend, with a wintery mix of precipitation over the Dakotas. GFS and European are stronger and further north with the low with snow falling over southern MB. Ensembles indicate southern MB getting brushed by this storm system, with 2-5 cm in Winnipeg, 5-10 cm near the US border and 10-20+ cm south of the border. All in all, I suspect GLB will trend further north with this system (as it often does), but odds are bulk of this storm's impact will remain south of the border.
ReplyDeleteRob!
ReplyDeleteAccording to the latest model runs I would say it is safe to say that southern Manitoba will see snow out of this system!
It's just a question of how much!!
Any chance of Southern Manitoba getting freezing rain tomorrow????
ReplyDeleteAs expected, latest GLB has trended north with weekend storm system, now showing some accumulating snow over southern MB with heaviest amounts of 10 cm or more over far south and southeast MB through Sunday. GLB shows about 5 cm for Winnipeg.
ReplyDeleteMost of the models I've been looking at are showing 10 to 20cm of snow south of the trans-canada. The GFS brings more significant snow into SW MB, but I don't buy that solution at this point. Since this system is quite similar to the Christmas one (in terms of duration), those snow totals will be over 2-3 days. That will probably keep this storm more low-key, unless we see a strong blowing snow component, which I don't expect at this stage.
ReplyDeleteThe NAM should begin showing off the full scale of this system tomorrow, which is an important third/fourth opinion to view.
Nice SE flow coming off forested regions combined with sun allowing for decent tmeps today...
ReplyDeleteFirst in a series of disturbances ahead of main low kicking off warm advection and lite precip. Lite snow or freezing drizzle should advect into SW Manitoba. Phase type really tricky with models showing what looks like dynamic cooling associated with upper disturbance.. however, if lift/saturation are not good thru dendritic growth layer.. we still could end up with frozen precip (a model cross section would be helpful).
I think first shot of precip will weaken as it heads north tomorrow and tries to overspread Winnipeg area. Warm/moist advection then recommences ahead of the next piece of energy Friday nite and Saturday.
A few points worth mentioning:
1) SW Manitoba appears to get the bulk of the precip with relatively dry and warm SE flow affects Winnipeg and SE Manitoba.
2) Just like the christmas system, strong circulation will cause very warm air to dumbbell north of low pressure centre. This time however, warmer air will be better entrenched further west. I therfore would expect potential for frozen and even liquid precip depending on how warm we can get at the surface.. especially where forcing and lift are not as deep like on periphery of precip shield.
Just throwing out some of my thoughts on this system.
Latest GFS (18Z) shows significant accumulations in Manitoba. The precip amounts in this run are very similar to those in the lead-up to the Christmas storm. The GFS had been showing more significant accumulations over southern Sasktachewan, which didn't make much sense to me. Now the model has shifted those heavy amounts further east over SW MB and southern Manitoba as a whole. This makes more sense than the previous runs.
ReplyDeleteHowever, it still remains to be seen as to whether this will all hold together. The models certainly have been trending in the direction of a storm for Manitoba, but it is still a bit far away to make any solid predictions.
Well it looks like southern Manitoba will get in on the action with this storm!!
ReplyDeleteWinter storm watch for ND with a concern of heavy freezing rain changing to a heavy snow with strong winds!!!
OH BOY!!!!
Models have really ratcheted up QPF amounts over the last 24 hours. The GFS gives 15-25cm for Winnipeg and south-eastern Manitoba, with higher amounts in SW MB. The GEM gives about 25cm for Winnipeg, and the NWS QPF chart gives Winnipeg about 20cm. The only outlier right now is the NAM. Ensemble gives Steinbach and Winnipeg a 50-60% chance of 10mm or more with this system. That percentage has been gradually rising over the past 24-48hours along with the other models.
ReplyDeleteAnyone see the potential for heavy ice accumulations with this storm for southern Manitoba???
ReplyDeleteSo when is this storm supposed to start?
ReplyDeleteHi from Grand Forks
ReplyDeleteI have been off for a few days and sick too... latest american model guidance showing a slight farther north shift similar to 00z ecmwf. heaviest snow band actually from wrn and nrn nd into Srn Sask and srn Manitoba...heaviest accums just using model qpf shows 10-15 inches Minot-Williston thru Brandon then northeast toward Winnipeg or the Interlake region. That is where it appears the true def zone sets up.
A rather complex system coming up over the weekend with uncertainty in track, strength, timing and precip phase that will influence eventual snowfall amounts.
ReplyDeleteSystem is double barelled to begin with, with Pacific energy spilling over the Rockies spawning a Montana low and a Colorado low. Montana low spreads snow over srn SK and SW MB Friday night into Saturday while Colorado low begins to intensify. On Saturday, main energy begins to shift to Colorado low while Montana low weakens. Colorado low begins to spread an area of mixed precipitation over Dakotas and Srn MB with snow, freezing rain and ice pellets likely keeping any snowfall amounts down initially, especially RRV and east. Warm air aloft occludes out Saturday night with pcpn changing over to snow Saturday night into Sunday along with increasing north winds. Heavies amounts likely over southern RRV and SE MB with 10-20 cm possible, higher amounts over ND/MN. Winnipeg could see 5-10 cm out of this, but still hard to say given all the uncertainty in track and pcpn phase. Stay tuned..
Hi Rob
ReplyDeleteDont mean to step on your toes up there... I did see the 12z GEM is more north and actually hits us better...it does seem a bit faster too with sfc low 12z sun compared to gfs (at least at first glance). Regardless another hit for most of ND with still some ?? for se Sask into Manitoba. I guess that is how it has been all year long.
No problem Dan.. we're all here to share! It appears the main storm will take a track similar to the Christmas one, although this storm is warmer and less intense by comparison. I don't think we'll see the same amounts as the Christmas blizzard, but the affected areas may be similar. Hopefully it doesn't hit you guys too bad to worsen the flood threat..
ReplyDeleteThanks Rob....
ReplyDeleteWe were looking at it...and the winds appear to be a bit stronger down here possibly than the last big one. The Christmas one was still slower and would not look for such extreme amounts as that one....but one never knows some def zone area may well see 18 inches but where?? The city has been working the last few weeks in clearing snow banks...will have to do it again.