Summary: November 6, 2018
Most of the Intermountain West saw a cooler and wetter than average October. The wet pattern has been a welcome shift from the predominantly dry pattern that plagued most of the region in Water Year 2018. And the cooler than average month is quite notable, as it is the first time this year for many locations in the IMW to experience a cooler than average month. Both temperatures and precipitation have stalled the drought. Snowpack accumulations are greater than the 50th percentile for many SNOTEL sites across the IMW - basin-averaged snowpack is well above average for all of Colorado, with mixed results in Utah and Wyoming. If the current pattern continues, we begin to start talking about drought recovery and assessing drought from a long-term impacts and hydrologic standpoint (since the impacts and the hydrology have the longest "memory" of drought).
Thanks to October numbers, and a decent start to November, improvements in drought depiction will be recommended. But improvements may not be as widespread as some may expect. The snow is a welcome sight, and the surface soils are responding nicely. But streamflows are largely still well-below average for this time of year, and reservoirs remain painfully low. These hydrologic variables may not see improvement until next Spring, so expect drought improvements to show up slowly and conservatively.
A mostly dry pattern is expected over the next couple of weeks, but with it some cooler than average temperatures over the next week. If the dry forecast pans out, there isn't likely to be much (if anything) in the way of improving drought depiction. We're still very early in the snowpack accumulating season, so expect those snowpack percentiles and percents of average to change quickly. Either way, we still have a long way to go! While we won't really have a clear idea how the snowpack season is unfolding until January, if the pattern shifts back to wet for the second half of November, that could mean two wetter than average months in a row - something that would really help towards improving the region's conditions and outlook.
Eastern UT: An area of improvement from D3 to D2 is recommended over Emery and Grand counties in eastern UT (green outline). While this area did not receive any moisture in the past 7 days, October precipitation for the area was well over 200% of average. Many surrounding locations (mostly higher elevation) saw improvements throughout October, but this area remained unchanged. However, given the ultimate outcome of October, the improvement seems warranted.
Northern CO: A one-category improvement around the Continental Divide and northern mountains is recommended (blue outline). Some of the lower elevation valleys of North Park and Middle park received 200% of average precipitation for October. The highest elevations along the borders of Routt, Grand, and Summit counties also received an additional 2-3 inches of precipitation in the last 7 days. SNOTEL snowpack in the area is in very good condition, with many sites ranking in the top 90th percentile of WYTD accumulations.
Southeast CO: A slight reduction in the D4 along the Sangre de Cristo mountain range is recommended (purple outline). This represents a small area that saw decent precipitation in the last 7 days and is showing up a little better on several different SPI timescales compared to the northern part of the D4 area.
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