Wednesday, January 06, 2010

Another cold blast on the way, but warming trend for the weekend into next week..

An Arctic ridge of high pressure over Saskatchewan will build southward into the Dakotas Thursday ushering in colder air over southern MB for today through Friday.  Increasing northerly winds today will bring down colder air from the north with daytime highs back in the low minus 20s over southern MB Thursday and Friday and lows near minus 30C. The good news is that the cold outbreak should not last long with a significant warming trend expected to develop on the weekend. Saturday will see gusty southerly winds start to flush out the Arctic air, with temperatures forecast to rise into the minus single digits by Sunday. Well above normal temperatures are expected through next week as a mild Pacific flow becomes established across the Prairies. In fact, long range models are indicating the potential of a January thaw developing by mid week with temperatures at or above freezing over portions of southern MB. Let the melting begin!     

31 comments:

  1. Rob!

    Model such as the ECMWF has gone completely BONKERS with the warm up!

    I have a feeling it won't get that warm but something more in line with the GFS seems right!

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  2. Models differ on the degree of warming, but agree that we'll be moving into an above normal temperature regime for next week. GFS is indicating +5C temps at 850 mb by Wednesday, which can translate to above freezing surfaces temperatures in favourable downslope areas such as east of the Riding Mtns, (Dauphin, McCreary), north of the Turtle Mtns (Boissevain, Killarney) and along the the western RRV (Portage, Morden) Elsewhere, snowcover will keep temperatures suppressed somewhat, but even Winnipeg can get above 0C if we get a westerly flow tapping all that mild air to our west.

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  3. There is also warmer and less snow south of us this year to moderate those south winds.

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  4. After that big Christmas blizzard, there's plenty of snow to the south of us through the Dakotas. A southerly valley wind coming out of a departing Arctic ridge won't warm us up like a westerly wind tapping a Pacific airmass.

    As daniel noted, ECMWF showing some dramatic warming next week with 850 temperatures of +15C over SK by Tuesday. Although extreme, I wouldn't discount it as a possibility. 850 temps have been known to reach those values with some Pacific influxes. Of course,that doesn't mean 15C at the surface, but it would give the potential for some record breaking highs across the Prairies next week. Here's hoping!

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  5. I just hope we don't get another ice storm this winter like last winter. That's the last thing we need.

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  6. Snow comment was in comparison to last year...see interactive Snow and Snow Water Content.

    http://www.nohrsc.noaa.gov/nsa/

    I

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  7. Thanks for that spring update Rob and Dan GF...Another warmup appears conjured up hopefully a la November.

    Is El NINO about to reintroduce its influence?

    I'd willingly suffer a brutally cold (AO) February if an El Nino influenced March early spring was the result. Unike Dan P I'm wishcasting with a quid pro quo.

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  8. Amazing how extensive this cold is. Temperatures below zero in florida, Georgia, etc.. And even in cuba, where it is only 13°C in Havana. Not the time to plan for a vacation if you wanted 30°C temperatures lying on the beach. In Havana temperatures apparently could drop below 10°C for overnight lows and daytime highs of only 18°C by the weekend.

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  9. Even if its too late to cancel , I'm sure most here would take that 18C and skip the ice in the Mojito

    ROB for those who head to that Latin Island and want to gloat while downing Mojitos, is there a minimalist version of OBS or BLOG??
    Internet connections like chocolate are not of the finest quality

    As you may have found after a few weeks in Italy last summer, there is a certain joy in checking home to confirm that you are in a much warmer place.

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  10. Temperature of -30 and Windchill - 43 at Brandon Airport at 8am .

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  11. Jim..

    No, I don't have a mobile version of Rob's obs or blog.. but I found they were quite accessible as long as you had a good wi-fi connection. But maybe I should come up wth a Rob's Obs "app" to download for mobile users!

    But yes, quite the chill down south. Photo in today's Free Press showing people wearing parkas on Miami Beach! They're calling it the worse cold snap in at least 15 years down there.

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  12. Why would they issue a weather warning for Windchills at or greater than -40 for almost all of Southcentral and Southweatern Mb not including Winnipeg when WC is -41 in Winnipeg

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  13. curiousgal..

    Environment Canada issues windchill warnings if they expect windchills of -40 or lower for at least 3 consecutive hours. Those conditions were more likely being experienced to our west, whereas it's right on the -40 borderline for Winnipeg and southeast MB. I wouldn't be surprised however if they extended the windchill warning for the RRV this morning with winds of 20-30 km/h and temperatures near -28C.

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  14. Rob,

    I'll just say that I was out helping Trish get off to work this morning, and while I was unplugging her car and scraping the frost off her windshield, I experienced the coldest I've ever been since I moved to this city. The wind was probably closer to 35-40 km/h (it funnels between the two apartment towers here), and it literally took my breath away. Within a minute or two I had ice frozen to my face from my eyes tearing up because the wind stung so much. It's miserable out there!

    Happy to say I'm back inside, warm with a latte in hand. But yowch, it was awfully cold out there this morning.

    - Brad V.

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  15. That would be a good idea for many Mb/Nd users but unavailable in some places in the Caribbean islands.

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  16. A -40 windchill can cause severe pain in minutes yet EC rquires it to last 3 hours before its worth a warning. .. whereas +40 Humidex consequences are cumulative over hours and days.

    A suggestion... lets empower only those at EC who have sufferred the consequences of a -40 WC to decide how long the duration must be before they warns us.

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  17. The CWB Weatherbug Network page (select CWB link) on ROB'S OBS Current Temperatures Page or my name ...has a desktop (and Mobile) Multi location Weather and alert app. It includes instant local and International locations such as Whyte Ridge School Winnipeg, Grand Forks AFB, Antler Saskatchewan, and Veradero where the high will be 15C on Sunday.

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  18. Hi everyone...

    Looking at those warm 850 mb temps just have me thinking how much will get to the sfc...with such very deep snowpack over our area (at least here in ND/MN/SD where most areas running 12 to 22 inches) have a very difficult idea of getting much above 25F...I havent looked a lot at day to day winds but if we do have a day with west wind could see 30F in the RRV. Best chance of 30F will be over the trees to our east and over some higher terrain to our west.

    I talked with our local in house climate expert. A very unusual pattern this winter with very few analogs to compare it to past years. Thus coming up with a year to help in long range forecasts has been a challenge.

    Here is a bit from what he sent us in office...
    From a statistical / analog standpoint there are few real analogs to look at for historical reference. Taken individually, each of the above signals present a different picture. Collectively, in the 60 years of data available, there is little real agreement. For example, in 2009 we had the strongest December negative AO on record, and second most negative OND period (2002 was first). There are few warm ENSO years for comparison, including 1958/1959 1963/1964 1965/1966, 1968/1969, 1969/1970, 1976/1977, 1987/1988, 1997/1998. It is important to note, while these are El Niño years, no moderate El Niño and strongly negative AO have coexisted in the record. One or the other was weak. From that standpoint, this year is unique. It is a common belief among the climate community that the extreme variability of the weather/short term climate is due to this juxtaposition of these signals.

    His conclusion that the northern valley will see more normal temps late Jan into February with normal to above normal pcpn....then what he suggests is a cold and wet March and April period.

    Here is more of what he says...
    "will assume the non classic El Niño response will persist in some form through the rest of the winter and into the spring. Primarily, the negative PDO and overall negative phases of the NAO and AO will dominate. Cyclical variances, probably MJO or like driven, will keep the pattern from being too La Nina like. I’ve chosen the 1966, 1969 and 1977 springs as the baseline as these three are the closest to the current scenario. The problem is those years in of themselves exhibit a great deal of variability; 1966 and 1969 were colder than normal, but opposite in precipitation. 1977 was quite warm, and only a little above the normal precipitation. So, I need to find another variable; the PDO. Using the PDO as a filter the springs of 1964, 1969, 1970 and 1977. So, we are left then with 1969 and 1977 as common years in all the filters used. Overall, the remainder of the winter and into April would be colder than normal, with precipitation being greatest during the critical March – April time period. The southern valley would be favored for the heaviest precipitation, which is at least continuity"

    There was a webinar from folks at ESRL PSD in Washington DC to go into detail on why the winter in the U.S. is so much colder than normal. Accu-Wx is saying coldest winter in U.S. overall in 25 yrs.


    -- Dan

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  19. I'm sure no one has forgotten the +6 °C we had on January 7, 2003. That was quite the high temperature event.

    On another topic, I note that heating degree days are computed daily in the Monthly Climatological Summary. What formula is used to compute degree days? Is it Dh=Tbase-(Tmax+Tmin)/2 ? Using that formula I get results close to those in the MCS.

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  20. That was nice it didn't get near as cold as forecasted last night.

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  21. A large area of low level cloud over the RRV kept us a good 10 degrees warmer last night than we could have been. Winnipeg stayed steady around -22C overnight while clear areas to our west dropped into the minus 32 to minus 36C range. Thank you low cloud!

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  22. Thanks for the great climate info, Dan..

    Interesting that 1977 is mentioned as an analog. That was the year in snowed in Miami! Although I don't think this winter is as brutal as 1977 was over eastern NA, there do seem to be some correlations. As you note however, this looks to be a rather unusual pattern this year with little precedence to work from. We'll have to see what kind of surprises Mother Nature will throw at us this winter..

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  23. Box..

    HDD (and CDD) on my Robs' Obs stats are computed based on the mean temperature for the day. My weather station software computes this daily average by looking at the mean temperature each hour and coming up with a daily mean, rather than just computing the daily mean between the day's high and low. Usually, it works out pretty much the same, but sometimes they can be a few degrees different when there's a sudden warmup or cooldown during the day.

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  24. rob, thanks for the explanation on Hdd and Cdd. It does sound like your method would give a better picture.

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  25. Dan- GF

    When ever there is a big storm headed to North Dakota area I sometime tune into WDAZ news!

    The weather forecasters on WDAZ are very trained and even give some insight into Southern Manitoba!!

    I even saw you on the news once explaining the happenings of the weather!!!

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  26. Dan GF
    What RR spring years result if you reverse the query process and filter years for the resulting Cold wet spring and near normal Winters with average precip.

    Filtering the remainder that began with dry falls and high soil moisture or freeze up river flow levels would leave us with someones January idea of Spring River potential.

    A Dry fall and less than extreme Feb deep freeze are two good omens at least for the northern RRV.

    Jim

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  27. Daniel P

    John Wheeler is great and Daryl is great too....though John is easier to chat with. We do have a media and emergency manger chat room where anyone can join and then it lets us chat with them on changes to the fcst, our ideas and any reports they have. This is in addition to our NWS chat we have with area offices. The big thing now is colloboration amongst everyone. You may not know this....but WDAZ weather casts are taped one hour before in the Fargo WDAY studios. The local WDAZ studio does have news and sports but weather is taped from Fargo but localized for the northern valley with info for southern Manitoba too. There are a lot of Manitobans in GF at all times.

    Jim

    So far it does look like a southern valley risk right now and much less risk north. A comparison on precip for Fargo and Grand Forks for Oct 1 to Dec 31 shows Fargo with the same precip amts as last year....Oct 1 to Nov 1 almost exactly the same with around 5 inches of precip and by Dec 31 up to about 7.50 inches of precip. Grand Forks much drier and about half as much as last year.

    River flows are still quite high and near record flows do exist in along the Red from GF southward...

    I will pass on your other ideas to our climate person to see if he as any answers for you.

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  28. Looking at the two years 1969 and 1977 produces opposite spring event extremes

    Peak RRV Peak Flow at Winnipeg was 187 cm/s in 1977 and 2,209 cm/s In 1969 a flood year and the first year we used the floodway. This compares to 3100+ in 2009

    Fargo for 1969 was the second highest flood in the twentieth century at 261 cm/s. Grand Forks also second at 1515 cm/s. For comparison Last spring the Peak Flow was 824 for Fargo and 2268 for Grand Forks.

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  29. Looking at the up coming warm weather and some sunny skies the fields around Winnipeg could very quickly become bare of snow. Most of the fields are wind swept with deep snow mostly around the edges and ditches it won't take much warming to get back to black soil. I'm guessing this could effect some tempertures in the future. Am I guessing right our is there not enough radiant heat yet to make much of a differenc?

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  30. Daryl.. if you get can a long enough stretch of above zero temperatures, plus sunshine and wind, that may be enough to melt away a minimal snow cover. Above freezing temperatures at night would really help. But you would need a good week or two of such conditions to make a noticeable depletion of snowcover.

    It has happened though. Back in January 1942, we had 3 weeks of exceptionally mild weather over southern MB that left fields bare by the third week of January. Farmers were out in their fields west of Winnipeg doing some winter clean up (click on my name for Winnipeg Tribune article)

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  31. Correction to that 1969 Fargo Peak River Flow S/B 716 cm/s not 261 which was at Wahpeton. Sources of Peak Flows are

    http://www.rrbdin.org/about/flood-tables.jsp

    Data for Winnipeg was from the Floodway IJC Report and from
    http://www.museedufjord.com/inondations/manitoba_eng/tumultuous_past.htm

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