Friday, April 03, 2009

NWS warns of potentially worse second crest..

NWS in Grand Forks has issued an updated flood forecast for the Red River in North Dakota, and it warns that a second crest due later this month may rival or even exceed levels from the first crest seen last week in Fargo. Due to record rainfall and snow in March in Fargo, NWS is predicting a 75% chance that the second crest in Fargo will reach the record 41 feet experienced in late March, with a 25% chance of reaching 43 feet. For further details, see NWS press release, and comments from Grand Forks meteorologist in charge Mark Frazier. What this means for localities downstream such as Grand Forks and southern Manitoba remains to be seen, as it will depend a lot on how much precipitation falls between now and this second crest. However, it certainly highlights the fact that the flooding threat on the Red will not be over with the passage of the first crest.


  1. Daniel P your words last weekend are prophetic...apparently all that pcpn froze in the fields. New aerial survey Robs words a few days ago puts us back to where we started except of course now Rapid Thaw ( a lot more northern water content) is a possibility as well.

  2. It is not surprising that there will be a second crest. Fortunately, the extreme cold of late slowed down run off and keep the first crest lower at Fargo. However, as temperatures moderate the flow will of course start again.

  3. Rob...

    What happened to the Emerson weather station. It was bad enough that Steinbach doesn't have its own station, but what happened to the next best thing?

  4. The Emerson weather station had to be shut down temporarily because of the flood threat.

  5. Well don't look now, but the parade of Colorado lows will keep marching on...

    The current low (which I referred to as Colorado Low #3 in an old post) is bringing heavy snow to Sioux Falls SD. By the time it 'leaves the building', there will be a contiguous snowpack all the way down to Omaha, Nebraska... ufff.

    Every 4-5 days a new disturbance drops south along the pacific coast and ejects out of Colorado. This is what GFS is advertizing:

    Around Apr 8/9 Colorado low #4 will take a progressive eastward track thru the central and southern plains. Its main effect on us will be to re-enforce cold advection and high pressure on its back side. This will suppress any real warmth off to our west.

    Then Colorado low #5 steps up to the centre stage. This guy looks interesting with a sharp SW upper flow ahead of it. At the surface there will be a long moist fetch on the eastern side of an inverted trough... sound familiar? QPF lights up on apr 13/14 over RRV... 850 hPa warm enough for rain with embedded convection possible... uh oh.

  6. Interesting feature on the hi-res visible satellite image over southern MB and North Dakota. Looks like a widening of the Red River waters (dark areas) over northern ND as well as south of Morris, I assume due to flooding. Really shows up nicely in contrast to the snow covered fields.

  7. ROB Does this explain NWS AHPS comment that the river is 11KM wide near OSLO in their 2nd Crest prediction

    In 97, IMOFM (in my occasionally functioning memory) there was a suggestion that the flood went overland around OSLO This would appear to explain why this years gage levels in OSLO exceed the record of 1997

  8. Rob, I was just going to comment on the same thing. It's quite something to be able to see the river flooding in the visible satellite images!

  9. Jim..

    Judging by the satellite image, it does look like the river is that wide from the Oslo area up towards Drayton, then again north of Drayton with a sharp cutoff south of Pembina (almost like a dike barrier). Here in southern MB, the river also looks quite wide southeast of Morris where the Roseau feeds into the Red.

  10. The North eastern point and the northern and eastern boundaries of that widening matches Cty Rd 1/10 and Mn. Hwy 175 meeting Hwy 75 in Hallock, Minn.

    Interestingly the USGS gage (Link on my name) on Two Rivers at Lake Bronson Mn about 9 more miles east on that road and 100 feet higher in elevation shows 70 to 80 inches of total precipitation in the last 7 days??

  11. Update on Apr 13/14th system...

    ECMWF depicts a split flow with upper low undercutting omega type block over the prairies (almost like a rex block). This solution would have us under a toasty airmass with rain/snow well off to our south.

    GFS show more phasing of the upper flow and cooler air over us. Surface low tracks up thru western great lakes with possible inverted trough affecting upper midwest with light rain and wet snow (ughh).

    168 hr GEM appears similar to European model and is even farther north with the upper ridge. Btw, why does EC do its best to hide GEM output past 144 hrs?

    Omega/ Rex block is a common pattern in April and early May for our region. However, given how much snow cover is present and how delayed the spring is... its a bit hard to buy such a large upper ridge setting up.

    The trend with this La Nina pattern and spring would seem to favor the GFS. However, the HPC (hydrometeorological prediction centre) and NWS favor the ECMWF solution ...

    Although still early, what are your thoughts Rob?

  12. Daniel..

    My gut feeling is that the main energy with that system will be concentrated over the southern and central plains (with some severe weather), with limited moisture advecting up over us along that inverted trof. I think we'll see some pcpn (mainly rain) but not much. That being said, the GFS has been the better performer this spring with most of the systems tracking through the plains, so we'll have to see how the models trend with this one. It's still too far out to discount anything.