5/6/15 Weather Summary

There was some rainfall overnight with the Linton NDAWN (North Dakota Agricultural Weather Network) station recording 0.44 inches so far.

Total rain through 8:00 AM May 6, 2015
Total rain through 8:00 AM May 6, 2015

The rainfall from overnight and what is currently falling along the I-94 corridor are the first two of many similar waves of rain that will work across North Dakota in the next 36 hours.

9:30 AM  Radar
9:30 AM Radar

Estimated radar returns from the HRRR (High Resolution Rapid Refresh) computer guidance shows in general terms what will likely occur the rest of today as an

May 6, 2015 Projected Radar
May 6, 2015 Projected Radar

area of low pressure that is currently along the lee-side of the Rocky Mountains moves to the northeast during the day.

8:00 AM May 6, 2015 Surface Analysis
8:00 AM May 6, 2015 Surface Analysis

The future radar in the animation above, only goes through this evening,  but below is an estimation of what the radar returns may look like Wednesday morning at 10:00 AM CDT.

Future Radar WRF-NAM for 10:00 AM Thursday, May 7, 2015
Future Radar WRF-NAM for 10:00 AM Thursday, May 7, 2015

Once the storm moves into Ontario, it will draw in some colder air for Friday and Saturday (and even Thursday for most areas).   In fact, freezing temperatures look to be a strong possibility on Saturday morning, especially across northern North Dakota.

Saturday, May 9, 2015 projected minimums from the NAM Guidance
Saturday, May 9, 2015 projected minimums from the NAM Guidance

 

European Center for Mid-Range Weather Forecasting (ECMWF) WMO-essential data at 850 mb show the possible cooling in the Day 3 to 7 range (May 9 to 13) in the graphic below.

850 mb anamolies
850 mb anamolies

 

Another storm will reinforce the cold air already in place on Sunday.  that system is expected to impact mainly southern North Dakota.  In the higher elevation in western South Dakota through eastern Wyoming and the Colorado Rockies, several inches of snow may fall (even double digit amounts in spots).

Sunday, May 10, 2015 Global Forecast System (GFS) projected surface map and precipitation type
Sunday, May 10, 2015 Global Forecast System (GFS) projected surface map and precipitation type

After Sunday, next week looks dry, just cooler.  Average temperatures in the 5 to 10 degree below normal range.  With clear sky, like what is expected this Saturday, some scattered frost on those mornings.   Above average or at least near average temperatures not expected again until after May 20.

Daryl Ritchison