 |
Forecast precipitation Apr 23 - 30th (inches) shows dry
conditions over Manitoba but wet south of the US border
(image from NOAA -WPC) |
The last week of April is looking mainly rain-free across most of southern Manitoba as a blocking ridge of high pressure over northern Manitoba maintains cool but dry conditions across the province. Temperatures over southern Manitoba will be in the 10-13C range Sunday through Thursday.. which is just slightly below normal late April highs (14C) But while we remain dry in southern Manitoba, it will be a different story south of the US border as a couple of strong storm system track across the central plains over the next few days. On Sunday, a storm system will track across South Dakota spreading showers across North Dakota and northern Minnesota, with locally heavy rain possible. The pressure gradient between high pressure over northern Manitoba and low pressure over South Dakota will result in a brisk easterly flow across southern Manitoba Sunday, with east to northeast winds of 40 gusting 60 km/h expected. Those winds will add a bit of a chill to an otherwise fairly nice day Sunday.
 |
Severe weather risk map for Tuesday April 26th
shows severe storms possible through southern plains
(Weather Network graphic) |
Tuesday will see another storm system tracking a bit further south, across western Kansas, bringing a severe weather threat across the US "tornado alley" from northern Texas through Oklahoma into Kansas. In fact, the US
Storm Prediction Center (SPC) in Norman OK has already warned of a potential outbreak of severe storms Tuesday with violent tornadoes and large hail possible. Stay tuned on this developing system for early next week. The system will also spread additional rain across much of South Dakota, some of it locally heavy. The system is expected to push east into the Ohio Valley by mid week with high pressure continuing to dominate over Manitoba. The result will be a dry week here with seasonably cool temperatures gradually warming to normal or above normal values by the end of the week. Overall, it looks like parts of North Dakota, Minnesota and South Dakota could see 25-50 mm of additional rainfall over the upcoming week.
Don't want to jinx anything, but both the GFS and Euro are showing no measurable precip for Winnipeg/RRV through May 5th along with a nice warming trend. That would be a good chance to dry out especially if we have a decent amount of sun through that period. Hopefully models stay the course. Whatever the case, it's looking more and more likely that we should be rainfree at least through the end of April, which would be nice. Need to dry out any standing water both for agriculture interests, and to and reduce mosquito breeding areas.
ReplyDeleteSunday was an excellent drying day for Winnipeg/southern MB. My average humidity was a very low 35% for the day, with a minimum relative humidity of 19% and a max of only 51% shortly after midnight. Combine that with those steady NE winds of 40 km/h all day with gusts to 50-60 and some afternoon sun, and that made for some excellent drying conditions. Should continue today, although winds won't be as strong.
ReplyDeleteLatest guidance continues to show an extended dry spell for Winnipeg and much of Manitoba over the next 7-10 days with little or no measurable precip through early May.
Too bad it's so chilly. Would be nice to see warm temps for once around here. Not meant to be I guess. Would also be nice to see a different wind direction other than from the east all of time. That strong east-northeast wind completely ruins everything. Not comfortable whatsoever.
ReplyDeleteSome guidance suggesting we'll be in the low to mid 20s the first few days of May.. so there's hope. (although not sure how long warm temps will last) But yeah, not much of a warmup this week until next weekend. At least we should be dry.. and we should see increasing amounts of sun. Could be worse (raining in North Dakota while it's snowing right now in SW SK and central Ontario!)
DeleteAnother pleasant day with near normal highs.. with more of the same, if not above average, by later in the period as mentioned.
ReplyDeleteIf not for the recent rains, the current QPF pattern would actually give some cause for concern. The extremely dry air and lack of precipitation - combined with still dormant vegetation - would set the stage for considerable wildfire risk, soil erosion etc. Even as it is, some regions with excessively draining soil may see some risk by next week (although these are not areas which are intensely cultivated - they will take longer to dry out as suggested).
Many years we see a dry period between the time the snowpack melts, and before the storm track migrates north over the Northern Plains (usually by May). In some cases, Rex blocks (high poleward of low) can give copious rains to regions south and west of Manitoba (with very sharp gradients) and leave us dry. The areas of high pressure typically retreat northwards allowing moisture and systems to track into Manitoba. However in a subset of cases, dry conditions in spring can perpetuate themselves into summer. In those years, convection is suppressed north of the 49th parallel, while areas just to south see considerable moisture and storms. So be careful what you wish for.
It's worth noting that agricultural areas in the Central Plains and southern Ontario do not experience the dry break that we get. Will we need to look at adaptation strategies to wetter conditions in the spring for some years (especially for the RRV south of Winnipeg) - in addition to the more publicized risk of drought?
It seems that we've been having a wetter climate in recent years.. wet episodes much more often that dry spells. I can't remember the last time we had a real dry year in southern Manitoba.. maybe 2006? Even then, we had enough subsoil moisture that there was little impact on crops, and in fact.. it turned out to be a very good bumper crop that year. Based on our subsoil moisture, I would say southern MB is probably in good shape to face a dry year or even two before we start seing widespread adverse effects from drought. But like I mentioned, true drought episodes in southern MB seem to be less and less common these days. (Not that they can't happen again.. they just appear to be less frequent than before)
DeleteWe also experienced drought conditions in 2011, and to a lesser extent 2012. We only just started to see some impacts before the pattern changed as you suggest (smaller streams like the LaSalle River almost dried up if memory serves). Clay soils in the Red River basin retain moisture efficiently - so a lot of agricultural areas are buffered against drought in the shorter term also.
DeleteLots of uncertainty in terms of future moisture regimes for our region. On the one hand, there is evidence to suggest that amplified upper patterns - which have been associated with droughts in the past - may increase. On the other, increased evaporation and shifting storm tracks may lead to more moisture advection locally. Specifically, big precipitation producers like Colorado Lows may shift north in the cold season, while MCSs do the same in the summer convective period.
Forecast high of 10C for Saturday for Winnipeg looks too cool.. most guidance suggests more of the same weather with highs near 15C. Not sure why there's been such a cool bias on day 3 temps lately.
ReplyDeleteHey Rob, what's happened to those forecasted temps in the 20s for next week? Is that unlikely now?
ReplyDeleteJohn Sauder is still forecasting highs in the mid 20s next week. So I think EC is just a bit conservative. Id say around 20 to 24C next week.
DeleteModels have been up and down a bit on the extent of warming next week, but it looks like we'll see low 20s by early next week, rising to mid 20s by end of the week. EC's temps do seem to be the coolest of the bunch..
DeleteHey Rob, great job on the blog. Keep it up! I have a question for you. With the way the weather has been lately, I am wondering when we may start seeing thunderstorms here. Do you have an idea as to when we may start seeing them? Your input would be great!
ReplyDeleteWay too dry for any tstorms over the next 7 days at least, possibly longer. No signs of higher dewpoints working into our area until perhaps weekend of May 7-8 at the earliest, but too early to say if we'll see a tstorm threat here. Precip chances look minimal over the next 7-10 days.
Delete