Thursday, November 29, 2007

Snow potential for Saturday afternoon

10:53pm - The going forecast looks good. We will start with a brief, but moderate, round of snow for Saturday afternoon before changing to freezing rain/sleet and rain. If anything, the evening models are decreasing our chance of freezing rain in favor of sleet. That would be a blessing! Sleet (ice pellets) are much easier to drive on versus rain freezing into ice. Adam will have coverage on Friday. Winter Storm Watch won't be upgraded to a warning until Friday evening.

The main threat with this winter storm will be in the form of freezing rain Saturday night. However, the precipitation will likely begin as snow in the mid-morning.

Snow could accumulate 1-3 inches across Northern Illinois with 3-4 possible in our Southern Wisconsin counties during the day on Saturday. Snow should changeover to freezing rain/sleet during the 3-7pm timeframe from south to north ending the snow accumulation. (Snow may be highly sought after if the freezing rain comes down for more than an hour or two.)

7 comments:

Tyler said...

acuu.weather Henry says theres no way the storm can go north of us because the models show it drawing warm air this far north when he feels it will go from Memphis to Detroit as an all snow system for us and an ice storm in central Illinois.He just feels there is just too much cold air entranched here to push the storm up and over this cold air.

Tyler said...

your thoughts eric.

Eric Sorensen said...

Tyler: I will read that. I've been knee deep in charts/maps/models. Haven't really gotten anyone else's throughts. Will post...

Eric Sorensen said...

http://www.accuweather.com/news-blogs.asp?partner=accuweather&blog=meteomadness is where his blog is (for those interested).

I don't buy the theory of the low going that far south right now. Sure, storms try to follow the line of greatest temperature contrast which will be down there. However, we will have such a streak (speed max) in the jetstream, I believe the models will phase the low northward into that jet streak.

The NAM model is giving us 1.70" of precip. The GFS is 1.09". The MRF is at 0.74". If accuweather.com's analysis was correct and we were all snow, we would be in the 7-14" range...which I highly doubt.

He does have some valid points. The low will go over land in SoCali tonight so the models will have better data. We'll be better ironed out tomorrow...but will go with about 75% certainty right now (through early Sunday).

Justin said...

Time will tell. Maybe you should take some bets with this guy, Eric?

Tyler said...

I still believe this system will be a little weaker then said.since the system is more weak than intended the storm will follow from northern Texas to Detroit.Bringing us more snow about 3' to 6' inches with ice in central Illinois.but things can change so... nuf said.

Justin said...

The 00z GFS is showing .5" at 48hr... and still above freezing temps. The NAM looks pretty close too. What time should we expect this system to actually make landfall. (Or on which model will it be)