03/20 – 03/21 Forecast: Winter (Spring?) Storm
Posted on 16. Mar, 2010 by Jesse in Forecasts
Have you got your vernal bliss on yet? If so, an early spring snow storm could be arriving just in time to help you get your groove on. It could be a whopper; hold the pickles! This evening’s model runs are in, with the 00Z suite of model runs (GFS and NAM) continuing the trend of better aligning the track of a potential weekend storm that threatens to bring the spate of mild weather that has befallen the Upper Midwest to a screeching halt.
The GFS has taken a more southerly route, depicting a surface low traveling near the I-44/I-70 corridor, from far Northeastern Oklahoma to near Terre Haute, Indiana by 00Z Sunday, with surface temperatures in the low to mid-30s as far south as the I-55 corridor. The latest NAM shows a fairly kindred forecast track, with congruous thermal profiles, and both models continue to generate more than adequate QPF values in excess of 0.80”. The 12Z ECMWF, the Canadian GEM and the JMA all have a similar placement on the progged location of the surface low by Sunday, though the Canadian GEM wins the award for being the most devious with the furthest southern placement. It should also be noted that while the 12Z run of these models showed a relatively similar placement of the low, they are moving the system through quicker than the 00Z GFS and NAM.
This system is still offshore, and therefore won’t be sampled by the upper air network for several more days. There are still plenty of uncertainties with this storm system, including the exact path, strength, amount of moisture availability, and most critically, the extent of any cold air intrusion on the northwest side of the system, which will ultimately be critical in determining the amount of snowfall that will be seen at any given locale.
Fitly, forecasting snowfall amounts this far in advance is rather impetuous; however, if these model runs have any degree of accuracy, somewhere in the vicinity of a line from northeastern Kansas to southern Wisconsin could be in line to see a fairly respectable early Spring snowfall on the order of 6”+ of a heavy, wet snow blanket. Expect that axis to very well shift north or south within the next 72 hours – stay tuned!
J. L. Risley
ECMWF 12Z SUN
GFS - 6 Hour ACCUM PRECIP 00Z SUN
NAM 12Z SAT / 1000-500 MB Thickness
GFS 00Z Sunday / 1000-500 MB Thickness
JP3 12Z SUN / 1000-500 MB Thickness
Canadian GEM 06Z SUN / 1000-500 MB Thickness
