Updraft: March 18, 2011 Archive

Flood update encouraging; "Supermoon" shines bright!

Posted at 5:20 PM on March 18, 2011 by Paul Huttner (4 Comments)
Filed under: Crow River, Flooding, Minnesota River, Mississippi River, Red River, Winter/spring 2011

It may be too early to breathe in a big sigh of relief just yet, but the latest batch of river forecasts from NWS Friday give us room to breathe a bit easier.

The latest NWS flood updates are out, and the news is encouraging.

Friday's river forecasts stop well short of the threshold of record river levels on most area rivers. While many rivers approach "major" flood stage by late next week, the previous forecasts of record levels appear to be unlikely, at least for now.

It's still relatively early in the process, and the amount of rain over the weekend combined with the potential for rain and or snow next week could raise the flood threat. Flood watches and warnings have been issued for many area rivers.

Here are the latest forecasts for some major river points in southern Minnesota as of Friday afternoon. (Specific forecasts for the Red River have not been issued yet)

Mississippi River at St. Paul: Friday's forecast timeline has the river still rising through next Friday to a level of 15.1 feet. This forecast keeps the level 10'+ short of record territory, and well below last year's crest of 18.38 ft on 03/24/2010.

(Click all images to enlarge)

The previous forecast had a 48% chance of reaching the record flood level of 26.40 ft reached on 04/16/1965. Friday's forecast seems to suggest the Mississippi will plateau well short of that territory this spring.

Here are the top 15 crests for the Mississippi at St. Paul. The current forecast for next Friday would tie for the 13th highest crest on record.

Historical Crests for Mississippi River at St. Paul

(1) 26.40 ft on 04/16/1965
(2) 25.00 ft on 04/15/1969
(3) 23.76 ft on 04/18/2001
(4) 23.60 ft on 04/30/2001
(5) 22.90 ft on 04/13/1997
(6) 21.90 ft on 04/16/1952
(7) 19.65 ft on 06/26/1993
(8) 18.38 ft on 03/24/2010
(9) 17.90 ft on 04/16/1951
(10) 16.30 ft on 05/16/1986
(11) 15.46 ft on 06/29/1957
(12) 15.45 ft on 05/04/1975
(13) 15.10 ft on 04/10/1994
(14) 14.51 ft on 06/23/2001
(15) 14.07 ft on 06/26/1984

Still the river may continue to rise well into April. Longer range outlooks show increasing chances for higher river levels the first two weeks of April. (Note: This simualtion was last updated as of February 28th.)

Minnesota River:

With the exception of Henderson, most river forecast points along the Minnesota appear to be encouraging.

Crow River at Delano:

This is some good news. Previous forecast for the Crow indicated a 35% chance of reaching record flood stage for the Crow in Delano.

St. Croix River at Stillwater:

The forecast of 84 feet at Stillwater by next Friday is good news. Though the River is still rising at that point, the lift bridge isn't closed until the river reaches 86 feet.

Bottom line: While flooding is expected as early as next week, the latest batch of river forecasts do not bring river levels to near record levels in most locations.

Lighter than average precipitation in the first half of March has helped lower porjected river crests. Only .33" of precip has fallen at MSP Airport in March.

Weekend shot of rain:

Rain and or snow in the next week will have an impact on rivers, but the effect is unclear at this time.

It looks like our next shot of rain will roll in Saturday night. This will be a significant rain, with forecast modles cranking out anywhere from around .25" to as much as .80" in one or two shots Saturday night into Sunday.

Stay tuned for further updates as we head into early next week.

"Super" bad moon on the rise:

Some call it the "Supermoon." You just may call it brighter than usual. The closest full moon (perigee) to earth in 18 years will mean the full moon appears 14% bigger and 30% brighter this weekend than when the moon is farther away (apogee).

We may not see the full moon on Saturday night with clouds and rain, but check it out tonight and Sunday evening if you can!

PH

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