Wednesday, March 16, 2016

Big melt ends with drenching rains.. colder weather on the way with some snow

Drenching rains this morning caused some street flooding
in Winnipeg, including this stretch of Academy Rd
It's been an exceptionally mild past 5 days over southern Manitoba, with record breaking temperatures soaring into the double digits, even in snow covered Winnipeg.  The mild weather has resulted in a rapid snow melt, with no snow on the ground now throughout the Red River valley including Winnipeg, which had a 30 cm snowpack just a week ago.  The thaw was punctuated by a soaking rain Tuesday through the Red River valley, with 15-20 mm of rain falling in most localities between 6 am and 2 pm. The soaking rain on the still frozen ground caused drainage problems with reports of locally flooded streets in Winnipeg and some overland flooding outside the city.

 The storm system that brought the rain has moved north and weakened while a new storm system takes shape south of Lake Superior. This storm system will spread an area of snow across NW Ontario and northern Minnesota Wednesday, with some of that snow reaching southern Manitoba by the afternoon.

Weather map valid 4 pm Wed March 16 shows band of
wet snow and rain over eastern Manitoba moving west
Usually, weather moves from west to east in our part of the world, but this band of precipitation will be moving into southern Manitoba from the east, as it rotates counterclockwise around the Lake Superior storm system. The band of snow may begin as some rain in the Red River valley in the afternoon but will quickly change to snow as temperatures drop. Snow will continue Wednesday evening with 5 cm possible by Thursday morning. Higher amounts of 10 cm are possible east of Winnipeg closer to the Ontario border, and in fact, snowfall warnings are posted for northern Minnesota and parts of NW Ontario for 10-20 cm of snow Wednesday.  (UPDATE: Snowfall warnings now issued for Sprague and Whiteshell areas for 10-15 cm of snow today) Keep that in mind if you plan on travelling east of Winnipeg Wednesday.   This system will be drawing colder air into southern Manitoba for the latter half of the week into next week with temperatures closer to normal for mid March. High temperatures will be near or slightly above freezing, with lows of minus 5 to minus 10. Certainly nothing abnormally cold for this time of year, but not as mild as the past week or so. 

32 comments:

  1. Snowfall warning issued for areas near Ontario border, including Whiteshell and Sprague. 10-15 cm possible today into this evening. Area of snow will be pushing west towards the RRV today, reaching Steinbach by mid afternoon and Winnipeg by late afternoon. Precip will likely start off as some mixed rain/wet snow here in Winnipeg/RRV as temperatures will be above freezing initially, before changing to accumulating snow this evening.

    ReplyDelete
  2. Thank's for the update Rob, I can't wait until it all melts again. Keep up the good work! XD

    -Mike

    ReplyDelete
  3. System is reminiscent of one which affected our region in late March 2009. Double barreled feature with initial inverted trough, followed by southern stream system and area of precipitation retrograding from the southeast. Probably could be a useful historical analogue, except that conditions were colder and winter snowpack was still in place.

    ReplyDelete
  4. 8 cm total at my place.. with a general 8-10 cm reported in the city. 10-15 cm east of the city with 15-20 cm near the Ontario border. Not crazy about getting the snow back, but picture postcard scenes out there with soft white snow clinging to tree branches..

    Doesn't look like it's going to melt quickly with no big warmup in sight for the next week to 10 days. High temperatures will be around the freezing mark during the next few days, with lows of -10C at night. A slow melt over the weekend if we get enough sunshine, but then models are hinting at another shot of snow next Tuesday with a few cm possible as a clipper system tracks through the Dakotas. So looks like our early spring has been postponed for a bit..

    ReplyDelete
    Replies
    1. That's a good thing Rob the river rose 18 feet in a couple of days without this added to it . We need a few more cool nights to get rid of all this

      Delete
  5. Rob, what does April look like for us in Southern Manitoba? Cooler or warmer than normal? I'm hearing the month could begin below normal. What are your thoughts on this?

    ReplyDelete
    Replies
    1. Mixed signals on April... Using composite analogues of past strong El Ninos shows a trend of cooler than normal Aprils for the southern Prairies and much of the US. But the last strong El Nino in 1998 resulted in a warmer than normal April over us. Losing our snowpack early will help us towards milder weather, but if we maintain a snowpack, then April is usually colder than normal. Right now, it's looking like near to below normal temperatures to close out March, but not enough confidence at this point to say how long that will last into April.

      Delete
    2. Just to add to my comments above.. the latest CPC outlook for the first half of April (issued today) shows a significant change from their past outlooks which had us generally above normal in April. Latest outlook now points to above normal temperatures favoured for the west coast with below normal temperatures from the Mississippi Valley into the Great Lakes. This would be consistent with an anomalous upper ridge over the west, and a long wave trough through the central continent which would favour cooler than normal conditions for us here in southern MB. So at the present time, it looks like a generally cooler than normal start to our official spring.

      Delete
  6. So much for a warmer than normal Spring

    ReplyDelete
  7. What's with this upper ridge thing on the west coast all the time. Seems to be a pretty common theme. All I can say folks don't expect much in the way of nice weather over the next few weeks or even months because these patterns don't go away just like that

    ReplyDelete
  8. Snow melting steadily with grass starting to show in some areas. 5-10 cm soil temps just above freezing (at Portage) with 5 cm and shallower layers isothermal near 0 C.. so ground heat flux is probably finished melting snow; and the March sun is taking over. Limited snowcover appears visible on webcams off to our south and west as close as Sanford and St Agathe.

    Guidance is likely too cool for places inside the city where temperatures made it above freezing today. This will be particularly true once we get a westerly and southwesterly flow by Saturday and Sunday off of the reduced snowcover regions. GFS and GEMGlobal have backed on off snow potential for the Monday/Tuesday system (dusting to 2 cm) with some uncertainty as to the track of the disturbance.

    Seasonably cool, but hopefully with a steady progression towards spring.

    ReplyDelete
  9. I hope everyone enjoyed the nice taste of Spring we had last weekend because it's likely going to be quite some time before we see those Temps again. You know we had a 30 cm snowpack that vanished within just a few days and now get a 8-10 cm snowfall that will likely still be around come April. Figure that one out. And to make matters worse, models are hinting at another 10+ cm snowfall Tuesday. Anthony to nite is that the last week of March, the period of March 27 to 31st is looking quite chilly, perhaps well below normal.

    ReplyDelete
    Replies
    1. Just a correction on my post from 6:32. It should have said another thing to note and Anthony to nite. Darn autocorrect.

      Delete
    2. Current snow will not last until April (except in piles and north facing exposures).. there is limited snowcover just 10-20 km SW of the city. Even locally, open areas are a mosaic of a few cm of snow interspersed with sheet water. Lots of moisture flux and latent heat release. Melting will accelerate Saturday and Sunday as we pick up a westerly flow.

      GFS and GEM Global 12Z runs showed a trace to a couple of cm accumulation for Tuesday's system. EURO show a different track for the disturbance.

      Delete
    3. I have been looking at the latest model runs and at the moment there remains 2cm for Winnipeg, but about 15cm in southwestern Manitoba. What are the odds of that happening? I am not wanting at all to be a bug, just simply stating a fact.

      Delete
    4. Mike.. Yes, latest guidance is indicating that bulk of snow with next clipper system will be falling mainly over SW Manitoba Monday night into Tuesday morning with a good 5-10 cm possible over Brandon-Virden-Pilot Mound-Melita areas, local 10-15. Winnipeg gets clipped with a dusting to 2 cm on the eastern flank of the precip shield. More snow the further southwest of Winnipeg you go. That's how it's looking now.. hopefully it doesn't trend further east.

      Delete
    5. Still looking like 5-10 cm for SW Manitoba this afternoon through tonight into Tuesday morning. Odd that forecasts only calling for 2 cm tonight in that area. Most guidance going with higher amounts. As for Winnipeg, we should escape with a dusting if anything.

      Delete
    6. Updated forecasts now calling for 5 cm over SW corner of the province. Still think some places near the SK border could see close to 10 cm by Tuesday afternoon.

      Delete
    7. 3-6 cm reported over SW corner of MB up to 8 am this morning.. snow continues there today with another 2-5 cm possible. Thankfully staying well to our southwest..

      Delete
    8. Generally 5-10 cm snow totals south and west of Brandon, including 11 cm in Elkhorn and 7.6 cm in Virden.

      Delete
  10. Rob Last weeks weather results in this weekends water sports select my name or copy and paste.
    https://www.icloud.com/sharedalbum/#B0UGfnH8tsLxDpQ;F10C24CD-C565-4317-AB90-AB46B29B81C4

    ReplyDelete
  11. Hi Rob,

    Another snow storm on Friday?

    ReplyDelete
    Replies
    1. Models are indicating a clipper system coming through Friday, but still considerable uncertainty about track and snowfall distribution. The Canadian GDPS has a track through ND, with about 10 cm for Winnipeg (although 7 cm of that is forecast to fall within 3 hrs). GFS has a similar track, but not as much snow for Winnipeg.. maybe 5 cm or so. The ECMWF on the other hand takes a track further north across southern MB, bringing the bulk of snow through the Interlake with a mix of rain and wet snow over Winnipeg/RRV and minimal accumulation. Bottom line, there is the potential for accumulating snow over southern MB Friday, but still too early to say where main axis of snowfall will be, or how much.

      Delete
  12. Are all models that were forecasting Friday's snow now saying the storm misses us?

    ReplyDelete
    Replies
    1. Not quite a miss.. but it's looking like we'll just get marginal amounts of snow across Winnipeg/RRV with it. More snow likely across Interlake with initial impulse, and then again over ND as system intensifies a bit as it tracks to our south.

      Delete
    2. Rob, for planning upcoming long weekend highway travel does it now appear that majority of any precip moving through the south with this next system will be a bit sooner now late day Thursday/Thursday night instead of during day Friday as earlier predicted?

      Delete
    3. Depends which way you're headed. Looks like area of snow will be moving out of southern MB from the north and west Friday morning, but could linger much of the day along and south of the US border into SE MB.

      Delete
  13. This comment has been removed by the author.

    ReplyDelete
  14. Hey rob, I just wanted to ask if we at all are going to see springlike weather soon? Wondering when our daytime high temperatures will start getting above 5C on a regular basis. I am kind of tired of seeing temperatures only a degree or 2 above zero and slightly below zero. What's causing this cooler than normal weather?

    Thank's.

    Here's hoping spring weather comes soon!

    -Mike

    ReplyDelete
    Replies
    1. Could be a few days now and then that we get to +5 to +8C, but nothing sustained into the beginning of April. Looks like a generally below normal temperature pattern shaping up unfortunately.

      Delete
  15. Yikes, models hinting at a major winter storm that could impact us later next week. Regardless of whether or not the storm impacts us, the real story is the chill that follows the storm. All long range models strongly agree on chilly Starr to April with daytime highs well below normal through at least and I say at least April 8th or so. Whatever to the idea that this was going be a warmer than normal Spring. Just an after thought now.

    ReplyDelete
    Replies
    1. I've been afraid of something like that happening.. We've been lucky here in Winnipeg/southern MB so far this March missing most of the storms. But if we continue to stay below normal into April, it's only a matter of time before we get hit. Hopefully our luck continues and we escape this below normal spell with minimal snowfall, but our luck can only hold out for so long..

      Delete