Summary: June 16, 2020
“What the rain giveth, the wind taketh away” – CoCoRaHS observer CO-WE-340.
While the Intermountain West saw widespread beneficial moisture early-to-mid last week, conditions have again turned for the worse. The last seven days have been hotter and drier than normal, particularly east of the Continental Divide. The eastern plains of Colorado have been 6-8 degrees warmer than normal for the month of June to date. This includes several episodes of 100-degree temperatures in SE CO, and widespread wind events. Agricultural weather stations have shown a sharp uptick in potential evapotranspiration, as has the Evaporative Demand Drought Index. Red flag warnings have been common, top soil is short, winter wheat crops are failing, cattle are being sold, and fire bans are in place. Eastern Wyoming has also been warmer and drier than normal, but last week’s rains were an effective stop gap measure to worsening conditions according to several condition monitoring reports.
The Upper Colorado River Basin west of the Continental Divide is likewise seeing its share of drought impacts. Most streamflows have peaked earlier than normal, and are now regressing to base flow. Large reservoirs are still benefiting from 2019’s snowpack, but have seen far less inflow this year. Soils and vegetation are mostly on the dry side as well save for a few lucky wetter patches. Red flag warnings are active today in western CO, NW NM, S UT, and N AZ.
The forecast indicates a cool down is on the way late this week, which will be accompanied by some scattered showers on the eastern plains. Fire starting lightning will be a major concern with this cold front. Precipitation totals are unlikely to break drought conditions. Further relief may be in the pipeline at 8-14 days out, but uncertainty is high.