Quote:
Originally Posted by dutchinnd
Thank you so much for the update! Thinking I'll spend my President's Day off at Sandbag Central . . .
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Your welcome...there is a lot that goes into forecasting far out for a river that is still frozen.
One thing I wish we (meteorologist-hydrologists) could scream out to the media is that this is an outlook probablity wise and not a "forecast" per se. A deterministic forecast (one with specific numbers for a crest) is not done til about 7-10 days before the crest. But when I see in the paper....forecast for xx point goes up in regards to the latest release it make me cringe as they are using the 50 pct line. That is not our number prediction. Our prediction covers the whole probablistic range. Past years spring precip is thrown into the river models based on current modeled conditions to come with different scenerios. I.E if 4 inches of rain fell like in 1979, then that produces a forecast of xx feet. If 2 inches of precip fell it produces xx feet.
The whole history of different spring precip is included and then probabilities are then done.... the outliers or 2 or 5 pct are the higher precip years....where are all clustered together that is a more confident idea.
So much depends on March-early April. The Ottertail river is very fast flowing that is different than 09. In March if we get a storm like 09 or a melt like it when it came pretty fast then probably can make the case crest will be worse than 09. That is a possibility, not a certainity. If we have weather like 2010 and it was dry then certainly it would probably be blo 40 ft.
The percentage outlooks were done in response to the 97 flood when most people focused on one number that was given as a possible crest for Grand Forks way back before the melt began. Thus little preparation was done for higher than that. In todays prob fcsts....the decision makers have all the data and scenerios and each city can make their own decisions based on more information. Sometimes the more info there is the more confusion there is and that can be the case with media. However, most city and county Emergency Mangers and city officials have taken a lot training and communicate internally with the RFC and NWS and understand our info more than we think.
My brief rant on this stuff....
Be safe
Will be watching the storms coming up. The one Sunday appears to brush the far southern valley with very tight snowfall gradient. Mostly 6-8 Lake Traverse with much less over Fargo due to high pressure north of us. Next psbl event around 24-26th.
--Dan