Winter storm update for N Plains

NAM forecast model from today to next Wednesday night

TIMING: WED-THURS

POTENTIAL IMPACTS: SIGNIFICANT SNOW FOR RRV POSSIBLE

NAM forecast model (above) depicts a significant shortwave trough ejecting (once more) into the North American continent. This will be our next weather maker mid-week. Another potent winter storm is expected to impact the Northern Plains and Manitoba. To which extent the main axis of precipitation will expand north is still uncertain.

"Wednesday-Thursday night: Strong upper low still projected to move towards the Northern Plains out Colorado, though trend has been towards slowing this down and shifting it a little further south. Consensus of models favors deformation axis extending up into our CWA with current track, with high QPF across our south Wed night into Thursday. Slower timing may favor majority of precip to occur after air mass becomes colder decreasing potential for rain or freezing rain, and increasing potential for heavy snow. In addition, strong wind signal as LLJ on NW side of upper low supports wind gusts 45 to 60 mph over our CWA (strongest on ND side of Red River Valley). Older snow pack will likely be crusted over, however if these strong winds align with snowfall then whiteout conditions would be possible. At this range further track changes would shift impacts away or further into our CWA, and impacts will be highly dependent on track/timing." -NWS Grand Forks, ND

"A strong storm system is forecast to develop next week and move into the northern Plains by mid-week. Initial guidance brings heavy precipitation into the region, along with very strong winds. While confidence is increasing regarding the strength and track, there remains some uncertainty with the exact amounts and transition points for the rain snow line. Continue to monitor the forecast for changes and updates." -NWS Grand Forks, ND

Below are the GFS (American) model trends. This depicts that this model is "trending" with southern extent of snowfall. It is possible that Manitoba will be missed completely by this storm system, which will be positive for spring flooding.

GFS model trends on snowfall accumulations

Below is the European model depicted the possible location of the Low pressure system on Thursday morning. Model depicts a rapidly deepening Low pressure, which is classic of intense winter storms/blizzards for the Northern Plains. A slight shift north will mean some heavy snow for parts of southern Manitoba.

ECMWF model for Thursday morning

Below is the NAM model depicting rapid cyclogenesis and intensification of the storm system on Wednesday.

500mb trough depicting a negative-tilt on Wednesday