Saturday, June 12, 2010

Better weather ahead

After days of cloudy skies and wet weather, it looks like things will finally be improving over southern Manitoba this weekend. A trough of low pressure over the Red River valley this morning will slowly track eastward today, bringing a flow of somewhat drier air into southern MB through the weekend. Some breaks in the cloud cover today will give way to more sunshine Sunday, with temperatures finally rebounding to normal values. Sunshine and warm temperatures are expected through early next week before more unsettled weather moves in by mid to late week. The month of June has been anything but summerlike over southern MB with generally cloudy cool and damp conditions becoming an increasing concern for the agricultural and recreational sectors.

19 comments:

  1. This is the local climate outlook from the local climate expert in our office in Grand Forks. This was posted June 10th 2010.... This is the abridged addition. I dont know enough of what he looked at so may not be able to answer any questions you have.

    As of this writing (6/9/2010) there were several very impressive systems in the western Pacific and Asian Continent and Indian Ocean region. Two such waves were exiting the China coast region and Indian Ocean region and would probably be here in the week two period.

    There is a fairly broad, but statistically significant correlation between the AMO and the summer precipitation across the region. The exact mechanism is not clear, but the fact that the AMO seems to be rising again this past spring suggests a wetter than normal summer. Of course, until I can really pin down a synoptic reasoning, it's only a correlation; how it interacts with the other large scale would be beneficial in determining the resultant 'weather'. So, at this time, suffice it to say the wet cycle seems to be a go.

    The basic trend in the composites is for a cool June, followed by a more tepid July and much warmer August. Will stay with that premise as the overlying theme and try to fine tune the outlooks with he more short term signals.

    The composites show a normal to cooler than normal June, with above climatology precipitation persisting. The axis of the heaviest precipitation would be in the central and western Dakota's, with the axis into the Devils Lake basin and northern Red River VAlley; where it seems to have been the past month or so. That does not, obviously, suggest all other areas will be dry but indicates that the current pattern may well continue.

    Time Latitude model: After three fairly significant waves pass the region very early in this period, there is a dearth of significant waves in out latitude until the end of June and first week or July. That would suggest that after the major rain threat this weekend, the weather should be a tad more quiet, which supports the composite based model. The strongest waves, and the few that have consistency, are on or about June 15, then July 5th and July 15th. There is a cluster of smaller, weaker signals in the June 22nd, 25th and 29th.

    The Outlook then for the remainder of June is a continuation of the basic pattern we've been in since the end of May; normal or a bit on the below normal side of temperature with normal amounts of precipitation, coming perhaps with greater frequency than one typically gets in the summer.

    ReplyDelete
  2. Dan - Silver Heights12:21 PM, June 12, 2010

    Off Topic - I just wanted to say thanks to Rob and to all the bloggers. I am moving to Ontario at the end of the month and will miss the RRV weather and the lively commentary on this site. Dan's wx will now be observing in Orleans (Ottawa), Ontario. Ciao y'all and thanks again.

    Dan Skinner

    ReplyDelete
  3. Best of luck out east Dan! Enjoy the balmy Ottawa valley (balmy compared to the Red River valley anyways..)

    ReplyDelete
  4. Hey Dan, wish you the best of luck! Hopefully it's warmer over there! Will be more humid for sure though! =D

    ReplyDelete
  5. This comment has been removed by the author.

    ReplyDelete
  6. Thanks for the info Dan-GF.. informative post. Sure hope the potentially heavy rain event for Thu-Fri doesn't pan out.. we badly need to dry out up here..

    ReplyDelete
  7. For those of you who are suffering from thunderstorm deprivation, here is an image that may brighten your spirits (click my name)...just forget for a second that it is 312 hours away.

    ReplyDelete
  8. What's that????

    That big yellow thing in the sky????

    Oh the sun......
    Finally some heat in the forecast!

    ReplyDelete
  9. Hi Rob...

    I am working today...if anything the short range models incl the gfs and canadian are indicating a bit farther north with sfc low and heaviest rains unfortunately from nw north dakota across southern manitoba.... we all need to dry out soon...my grass is out of control.

    ReplyDelete
  10. I'm hoping the models keep trending north and west with Thursday's system.. although that would still mean heavy rain over our Interlake regions and southern SK where they don't need any either. I see HPC is indicating 3.5" of rain over SW Manitoba between Wed and Friday which is a bit troubling!

    ReplyDelete
  11. If the system does trend farther north and west as Rob hopes, that would put southern Manitoba under the threat of very severe storms. So I agree with Rob 100%, lets move that system back into Saskatchewan!

    The next few days should be full of interesting discussion regarding the severe weather threats on Wednesday and Thursday.

    ReplyDelete
  12. Looks like a lone storm in the interlake area heading south!

    I wonder if it will hold together to give Winnipeg area a quick hitting thunderstorm??

    ReplyDelete
  13. Interesting storms through the Interlake. I'm surprised at how strong that one storm has become. It is taking full advantage of the 500J/kg of CAPE. Must be some kind of lake-breeze enhancement, in addition to the 30kts of shear at 700mb.

    ReplyDelete
  14. Yes, those cells are developing along a nice lake breeze convergence line between the NNW flow off Lake Manitoba and a NNE flow off Lake Winnipeg. Cells are heading pretty much due south along Hwy 6 with some quick bursts of rain (5.6 mm in Eriksdale) and some outflow wind gusts (60 km/h at Oak Point near St Laurent) Cells should weaken quickly over the next hour or so as we lose daytime heating.

    ReplyDelete
  15. Compact, almost Rex block pattern in place. Remnant upper low and associated precip brushes SE Manitoba tonite, although best warm and moist advection target areas over NE Minnesota.

    Atterntion then turns to next disturbance for Thursday. A couple of issues:

    1)Models like GFS show an absence of warm advective precip ahead of system owing to mid level cap. Amount of convective debris on Thursday of course will impact amount of destabilization that can occur before surface trough comes thru sometime Thur evening.

    2)Any convection will have to overcome warm mid level temperatures initially and a lack of upper support. Bulk of lift will be focused in the colder sectors of the disturbacne over Saskatchwan and central Manitoba.

    3)Best low level shear (backed low level winds) will be along and north of warm front progged to lift into northern RRV by aft.

    My first guess at this point would be for some isolated severe cells (cannot rule tornadic possiblity) to form along and north of warm front. Due to lake of lift and inital strength of cap, I would look for scattered severe storms to form along surface trough where mesoscale forcing is maximized ie lake breeze/ differntial heating boundaries.

    As cap breaks down, cells may have a tough time organizing as LLJ is umpressive and not well focused. Given mainly unidirectional shear atleast some bowing line segment may develop.

    ReplyDelete
  16. PS...

    It should be noted that most other models are further south and east with system and warm front than GFS. GGEM shows significant QPF over us rather than being displaced to the NW over Saskatchewan. We'll see...

    ReplyDelete
  17. Rob!

    It was a STUNNING 31 C in Churchill today!!!

    I'm assuming that was a record????

    ReplyDelete
  18. That's just nuts. The average there is like 11 or 12°! And, we haven't had 30C in Winnipeg yet this year!

    ReplyDelete
  19. Most people don't realize that Churchill is at sea level on the shores of Hudson Bay.. With a southwest wind, they can get quite warm in the summer months as they tap the full potential of downslope heating.

    That 31C was indeed a record for them today (prev hi 30.6C 1955), and they were the Canadian hot spot to boot!

    ReplyDelete