12/5/12

12/6- Update on Storm Aiming at Southeast Lower Michigan on Sunday Projected to be Weaker System

12/6/12-Update
 At this time; reviewing all the guidance on the storm forecast to move into Southern Lower Michigan, I see some minor changes at this time to the general forecast as it looks as though it will be a weaker system. Little change in the general forecast is anticipated as this system should still be mainly a rain producer for extreme Southeast Lower Michigan. Some mixed precipitation further north, mainly I-69 northward is likely. However at the onset; snow or mixed rain and snow is still likely over the entire region as the low moves toward Southern Lower Michigan on Sunday. Warmer air will be drawn northward into the region and thus; any snow or mixed precipitation at the onset, should change to rain over extreme Southeast Lower Michigan. Further north and west away from Metro Detroit; a mix of light snow, sleet and light rain is likely. Amounts will be mainly light across Southeast Lower Michigan with accumulating snows possible further north in Michigan. In any event; all models display a weaker system moving through the Lakes with much lighter precipitation.

12/5/12...
The first winter storm of December is slated to develop over the southern Plains over the weekend; track across the lower Midwest and then head northeast into Southern Lower Michigan by late Sunday night and Monday morning. As the system approaches from Missouri Sunday; cloudy skies and a stiff east to northeast wind early will be the forerunner of some light snow and/or mix precipitation developing Sunday afternoon before changing over rain Sunday night over extreme Southeast Lower Michigan. Further north; from I-69 (Flint to Port Huron) and points north; the changeover may not occur until toward Monday morning. Some accumulation of snow before the changeover is possible anywhere but the main risk would be over the northern areas of Southeast Lower Michigan. Look for all precipitation to change back to snow on Monday as colder air floods the region from the northwest.

This scenario is just a preliminary heads up on the system as our models have been variable on the the exact track. At this time; however it does appear the center of the storm and low pressure system will ride into Southeast Lower Michigan by Monday morning; and that usually brings a mix of precipitation with more rain east and south of the center; and more snow north and west of the center. At this early date; I wouldn't be surprised if the track isn't projected  correctly and may be further west since data that is being sampled and projected is scant at best; so stay tuned. Anything can happen with the track when better data is sampled and I will update as she approaches!

In the meantime; a weaker system will scoot across the region Friday night into Saturday morning and bring the risk of some light rain and snow showers across the region.

The maps below look reasonable and are from HPC for Saturday morning and Monday morning. As the time draws closer; I will include my own drawn maps from preferred models.




Making weather fun while we all learn,
Bill Deedler -SEMI_WeatherHistorian