Monday, July 25, 2011

Another chance of showers and thunderstorms Tuesday into Tuesday night..

A low pressure system developing over Montana is producing scattered thunderstorms over the western Dakotas this evening, and these are expected to continue overnight as warm and unstable air push north. Some of these storms are likely to spread into SW MB overnight with locally heavy rain possible. On Tuesday, these thunderstorms will push eastward and weaken bringing cloud and a few showers to the Red river valley by afternoon. Additional thunderstorms are expected to fire up over SE Saskatchewan and western ND late Tuesday into Tuesday night. Most of the strongest storms are expected to stay in North Dakota where severe storms are possible, but some thunderstorms may track across the border bringing locally heavy rain to portions of the RRV. It remains to be seen if this area of precipitation will get into Winnipeg as models hint the heaviest rainfall may occur south of the city Tuesday. Will Winnipeg miss out again.. or will we finally see our first significant rainfall of the month? Stay tuned..

19 comments:

  1. Early morning PASPC update mentions storms developing in Saskatchewan this afternoon and pushing into southern Manitoba this evening with wind and hail possible.

    Not sure but, from what I can see, things aren't looking all too bad this morning. Elevated convection isn't all that impressive out west which should help for surface heating later on today.

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  2. Cross-posted from my blog (http://aweathermoment.tumblr.com):

    Taking a look at the weather this morning, it appears that the 00Z and 06Z model runs of the GEM Regional were far too progressive and deep with these systems. As a result, they brought in a large area of rain by late this afternoon.

    The GFS and NAM have been a bit more consistent; in particular, I like the GFS solution as it doesn't seem to be over-doing convection and has these systems represented pretty well.

    All this means that I still think there's a chance that the precipitation will split as it approaches the city. Personally, I hope it doesn't, but the chance is there.

    Otherwise, it looks like a good convection day near North Battleford, SK as well as further south, along the North Dakota/South Dakota border where the SPC has issued a Moderate Risk for today.

    All sorts of interesting weather -around- Winnipeg...maybe it'll make it's way into the city one day.

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  3. Yeah, that elevated convection out west not as impressive as earlier expected. Models still show MCS type system tracking along intl border into tonight with some heavy rain, as well as potential severe wx over ND/MN. RGEM shows 56 mm bullseye tonight over Emerson area while NAM shows similar max amounts but displaced further east over northern MN..

    Looking at current satpix, radar, and upper air/surface analyses, everything points to the main action remaining mainly over ND today into tonight. We'll see how much activity if any can cross into Canada..

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  4. Starting to look like there may be some local flash flooding in NW ND as the thunderstorms train off the warm front.

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  5. took a look at the NWS forecast loop looks like an area of severe storms could be over us by 1 am as depicted on this page. Copy and paste.
    http://www.hpc.ncep.noaa.gov/basicwx/bawx_nav.php?imgtyp=ter&arrval=1&vtime=Wed_06Z&ptime=Wed_00Z&ntime=Wed_12Z

    Any thoughts?

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  6. @Mike:

    It's a pretty tricky situation, as postulated yesterday. Currently, convection continues over north-central North Dakota, providing lift and moisture for the air overrunning the warm front. This has brought a large plume of moderate rain into southwestern Manitoba (Melita/Pilot Mound areas) that is slowly tracking eastwards.

    The northern extent of this plume will be difficult to predict. If you prog. the precip using advection of theta-e values, the precip will stay to the west of Winnipeg most of the day, weaken as it moves through, then re-intensify east/northeast of the city.

    However, there seems to be very little development along the trough, with the idea of a large band of precip. arcing from ND all the way back to the upper low in SK just a pipe dream. If nothing there develops, there's a good chance this area of rain in SW MB will continue to chug along and just graze the South Perimiter with maybe a few drops inside the city.

    One thing is for certain: Winnipeg will see much less rain than areas even 25-30km south of us.

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  7. Also, while we may end up hearing a rumble of thunder or two, I think severe storms are a non-issue for Winnipeg today.

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  8. Thanks for letting me know,now I don't have to worry about watching for the storms all night and then missing out. I'm still an ameature at forecasting, Im learning. thanks again B7

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  9. If anyones curious about the thunderstorm odds heres what NAV Canada is saying on the metar/taf, hope you can read it.

    TAF CYWG 261746Z 2618/2718 20010KT P6SM SCT100 BKN250 TEMPO 2618/2620 P6SM -SHRA FM262000 15012KT P6SM SCT040 BKN100 FM270200 13010KT P6SM -SHRA OVC030 TEMPO 2702/2707 VRB20G30KT 2SM TSRA BKN008 BKN020CB FM270700 14006KT P6SM -RA OVC010 TEMPO 2707/2711 2SM -RA BR OVC004 BECMG 2709/2711 26008KT FM271100 26008KT P6SM OVC008 TEMPO 2711/2714 BKN020 FM271400 26012KT P6SM BKN020 BECMG 2714/2716 SCT030 RMK NXT FCST BY 270000Z=

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  10. Last day with over 5mm of rain in Winnipeg was June 22nd.

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  11. Ohhhhh...look at all that rain pass to the SOUTH of Winnipeg....
    Surprised????

    Look at all the convection out west....watch it all fall apart before it hits the city...maybe???

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  12. The TAF for all Canadian Aerodromes is written by Environment Canada for Nav Canada to disseminate. The TAF is an E.C. product.

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  13. I don't think we're gonna get a drop of precip out of this junk to the west - it's all busting up.

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  14. ANOTHER MISS!!! Saw it coming though. Keep waterin that grass.

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  15. Oh no...not another miss!!
    Ok???
    Who activated the storm shields last night?????

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  16. I can't wait for 2011 to end...

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  17. Got about 3mm at my place last night during a spell of moderate rain that lasted from about 12:20-1ish. My grass is happier already :)

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  18. Really? I didn't get a drop!

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  19. Had a few drops on the west side of Charleswood, but that's it, a few drops. Wouldn't have even registered.

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