1. National Weather Service Steve Gohde WFO Duluth Observing Program Leader Craig Schmidt WFO Twin Cities Service Hydrologist January 6, 2015

2. Weather and Hydrologic Discussion Weather review for mid-late 2014 (precipitation and temperatures) Current Conditions (Snow Pack and Frost) Winter Short and Long range outlooks Drought outlook Hydrologic long range outlook for Island Lake Reservoir

3. Island Lake Basin

4. Weather and Hydrologic Discussion Weather review for mid-late 2014 (precipitation and temperatures) Current Conditions (Snow Pack and Frost) Winter Short and Long range outlooks Drought outlook Hydrologic long range outlook for Island Lake Reservoir

5. Temperatures Oct. – Dec. 2014 Duluth T EMPERATURE H IGHLIGHTS T EMPERATURES COMPARED TO NORMAL S EPT +1.8 O CT +1.6 N OV -7.0 D EC +6.5 J AN B IT OF B OTH S NOW A CCUMULATION BEGAN N OVEMBER 9 TH RD. M ELTED TO 1” BY D ECEMBER 15 TH.

6. Precipitation at Duluth V ERY N EAR AVERAGE FOR 2014

7. July – Dec. Precipitation at Duluth B ELOW AVERAGE STARTING IN S EPTEMBER

8. July – Dec. Precipitation at Brimson

9. Observed Precipitation P RECIPITATION H IGHLIGHTS V ERY N EAR AVERAGE FOR 2014. A NNUAL PRECIPITATION MAY NOT BE A GOOD INDICATION OF CURRENT BASIN CONDITIONS. C ONSIDER PRECIPITATION SINCE J ULY. D ULUTH 4.04 INCHES BELOW NORMAL B RIMSON 3.80 INCHES BELOW NORMAL. A BNORMALLY D RY C ONDITION ON D ROUGHT M ONITOR

10. Water Year Precipitation at Duluth

11. Water Year Precipitation

12. Local Observations December thaw may have moved a portion of melt water out of the basin. Rain on snow dramatically reduced snow depths. Latest Snow Depths range from 3 to 6 inches in the basin. Latest storm fell mostly north of the Laurentian divide. Frost depth is diving quickly with thin snow pack.

14. Precipitation – Water Year Percent of Normal (YTD, since Oct 1) Pcpn: Much of MN well below normal so far, equating to about 1.5 to 2 inches of water

15. Weather and Hydrologic Discussion Weather review for mid-late 2014 (precipitation and temperatures) Current Conditions (Snowpack) Winter Short and Long range outlooks Drought outlook Hydrologic long range outlook for Island Lake Reservoir

16. Dec 5, 2014 – Snow Depth Source: NOHRSC Depth: 4 to 8 inches over the basin when model was run

17. Snow Water Equivalent (SWE) – Dec 5th Source: NOHRSC SWE: only up to about an inch when model was run

18. Source: NOHRSC SWE: slight increase since early December Snow Water Equivalent (SWE) – Jan 5th

19. Dec 31, 2014 – Snow Depth Source: NOHRSC Depth: 4 to 8 inches over the basin when model was run

20. Weather and Hydrologic Discussion Weather review for mid-late 2013 (precipitation and temperatures) Current Conditions (Snowpack) Winter Short and Long range outlooks Drought outlook Hydrologic long range outlook for Island Lake Reservoir

21. Extended Outlook – 8 to 14 Days Temperatures: potentially milder pattern next week Pcpn: continued below normal http://www.cpcpara.ncep.noaa.gov/

22. 30 Day Outlook – January 2015 http://www.cpcpara.ncep.noaa.gov/ Temperatures: Rest of Jan a little below normal Pcpn: Equal Chances

23. Jan, Feb, Mar 2015 Outlook Pcpn: Equal chances Normal Precip (liquid): Jan -- 1 to 1.5 inches Feb – ~1 inch Mar – 1 to 2 inches http://www.cpcpara.ncep.noaa.gov/ Temperatures: Equal Chances

24. Mar, Apr, May 2015 Outlook Pcpn: Equal Chances Normal Precip (liquid): Mar 1 – 2 inches Apr – 1.5 to ~2 inches May – 3 to 4 inches http://www.cpcpara.ncep.noaa.gov/ Temperatures: Equal Chances

25. Ocean and Atmospheric Influences on MN Weather Patterns Conditions in the east Pacific are still considered ENSO Neutral this week, though there is a 65% chance of a weak El Nino later this winter and spring. Pacific Ocean water temperatures are expected to be about 0.5 to 1.0 degrees above normal. However, weak El Nino conditions do not have a strong signal on precipitation patterns over the upper midwest. “Equal chances” seems about right for the upcoming winter.

26. Typical El Nino Precipitation January and February – No clear signal in departure from normal

27. Typical El Nino Precipitation March – No clear signal; April tends to be a little drier than normal Summer months (not shown) – mixed bag, some wetter, some drier

28. Environmental Canada Forecasts Jan, Feb, Mar -- Precipitation http://www.weatheroffice.gc.ca/saisons/index_e.html#forecasts Chance of above normal pcpn to the northwest

29. Environmental Canada Forecasts Jan, Feb, Mar -- Temperatures http://www.weatheroffice.gc.ca/saisons/index_e.html#forecasts Increased chances of below normal temperatures nearby

30. Weather and Hydrologic Discussion Weather review for mid-late 2013 (precipitation and temperatures) Current Conditions (Snowpack) Winter Short and Long range outlooks Drought outlook Hydrologic long range outlook for Island Lake Reservoir

31. Drought Information Change from normal to D0 (abnormally dry) in the region

32. Drought Information Drought outlook: Little change through the winter for our area of interest

33. Weather and Hydrologic Discussion Weather review for mid-late 2013 (precipitation and temperatures) Current Conditions (Snowpack) Winter Short and Long range outlooks Drought outlook Hydrologic long range outlook for Island Lake Reservoir

34. Soil Moisture Components in Basin SWE -- very low, but early UZ (Upper layers): Little free water, tension water in the lower half of normal LZ (Lower layers): tension water low, free water normal ADI (Above ground): just below normal

35. Chance of Reaching Refill Demands (Normal Operating Conditions) Summary: using “normal” condition operating rules, we have a 20-30% chance of reaching target pool level by June 1 st (vs. normal chance of 60%) Lower confidence than average

36. Chance of Reaching Refill Demands (Dry Operating Conditions) Summary: using “dry” condition operating rules, we have a 65% chance of reaching target pool level by July 15 th (vs. normal chance of 80%) Close to average confidence

37. Summary Precipitation – Slightly below normal for the past 6 months Temperatures – Temperatures have been around normal. Drought / Soil Conditions– Slight degradation to D0 Short Range outlook (Jan) – Nothing spectacular either way Longer Range – No strong indicators to forecast above or below normal temperatures or precipitation Hydrologic Outlook – Confidence is lower than average for successful fill in normal (20-30%) operating conditions; much more confident (65%) at dry operating conditions