4/7/2015: Light Mix

Overnight some light rain and snow did fall, but only in locations where surface dew points were in the 20s or 30s.  Much of the Red River Valley and northeastern North Dakota recorded no snow, or perhaps just a few flurries as the precipitation evaporated before reaching the ground.  That moisture falling from a cloud but evaporating in the drier air, near and above, the surface is referred to as “virga”.

Dew Point Temperatures this morning at 7:30 AM
Dew Point Temperatures this morning at 7:30 AM

An example of this would be the radar image below that shows some returns from the Fargo area, where either no snow, or just a flake or two was seen near the surface.  The dry low levels of the atmosphere could not be over come by the moisture falling from the clouds, so in turn it the snow flakes turned into water vapor before reaching the ground, which already referred to as “evaporated” would technically be a sublimation process as snow (solid stage of water) turns into a gas directly which is a sublimation process.  In any case, instead of waking up to a dusting of snow, only a couple of renegade flurries were observed.

mayville radar
Radar Image near Midnight

Although the rain and/or snow did not reach the ground in eastern or northeastern North Dakota, elsewhere it did.  There was some rain and mist across far southern North Dakota and much of western North Dakota recorded snowfall.

Tuesday, April 7, 2015 Road Conditions
Tuesday, April 7, 2015 Road Conditions

You can almost visualize the locations that did record snowfall overnight by the road reports this morning.  A view from the NDDOT camera near Washburn, ND also confirms the snow at least in that location.

washburn west
Washburn, ND NDDOT Camera view from 8:17 AM April, 7, 2015

The snow that is currently in central and western North Dakota is expected to move to the east / northeast during the day.  Southern North Dakota into the southern Red River Valley the precipitation is expected to be mainly rain after some initial snow potential, whereas, northeastern and northcentral North Dakota will probably record mainly snow.  Because this precipitation will be moving into a region with very dry low level atmospheric air, the precipitation that does reach the ground looks to be on the light side.  Liquid equivalency under 0.25 inches is progged with most locations staying under 0.10 inches, so not a huge precipitation event today.

Radar Projection for Tuesday, April 7, 2015.
Radar Projection for Tuesday, April 7, 2015.

 

Additional moisture is projected for late Wednesday into Wednesday night mainly across southern North Dakota.  That also looks light with amounts under 0.25 inches with most under 0.10 inches once again.  Although southeastern South Dakota, southern Minnesota, especially Iowa through Illinois and Indiana may record localized 1 inch amounts (plus) in the next few days, most of North Dakota although recording some moisture will receive very little from this event so the general dryness of the state will continue in the short term.

There may be some rain showers along a cold front on Sunday, otherwise, there will be minimal threats of moisture for the state in the next 10 days beyond Thursday morning.

Daryl Ritchison