NWS LOT STATEMENT

The Chicago office if the NWS has put this in their forcast discussion...

THERE ARE SOME EARLY INDICATIONS THAT A SIGNIFICANT WINTER STORM
COULD DEVELOP AND POTENTIALLY AFFECT ALL OR PORTIONS OF NORTHERN
ILLINOIS OR NORTHERN INDIANA WITH SIGNIFICANT SNOW OR ICE MONDAY
NIGHT INTO TUESDAY. MANY VARIABLES NEED TO COME INTO PLAY FOR A
SIGNIFICANT WINTER STORM TO DEVELOP...AND IF JUST ONE IS MISSING...THE
POTENTIAL FOR A MAJOR WINTER STORM DECREASES SUBSTANTIALLY. IN
ADDITION...ONLY A SMALL CHANGE IN THE FORECAST TRACK OF THE STORM
WILL MAKE THE DIFFERENCE BETWEEN SIGNIFICANT SNOW...ICE...OR MOSTLY
RAIN FOR NORTHERN ILLINOIS AND INDIANA.

It's White Outside Again

The clipper brought in an inch or so of snow. Occasional light rain has been reported and it is freezing on surfaces. Other than making some slick conditions, it should not cause any major problem with downed trees or power lines. (Of course that isn't stopping the crazy drivers from having wrecks everywhere.)

Next week: It has been a roller coaster of a ride and the storm is shaping up to be a good one but I think it will be a swing and a miss for us. The warm air pushing put of the gulf has moved the rain/snow like north of Indiana. There does appear a significant amount of rain is on tap now. (If snow we could have easily made 10-15 inches.)

However snow lovers should not give up hope yet. There still is some final adjusting of the final path and the clipper system can now be officially sampled that data used by the models. The ensembles also show some solutions where we are in thick of it. We just need to wait and see.

Next Weeks Storm

Let's put the weekend clipper system behind us for now. It is pretty much a lock for a 1" snowfall on Saturday.

The big question looming is the Tuesday system. It has trended west/northwest a bit in the 12Z model runs. That is good for the precipitation. The bad news is the temperatures are too warm. For snow to fall, you need a small handful of items to occur.


You need moisture/precipitable water, a thickness pressure of 540mb, and the surface temperatures and 850mb (5000') temperatures to be below freezing. A warm southern flow which is making a nice transport of moisture from the gulf is also bring up warm temperatures.


Both the surface and 850mb temperatures are marginal at best. There should be some backside snow but the font end would be loaded with rain. That is nothing but bad news for snow lovers.


If there was some good news in this is there still is a lot of time between now and the actual storm. The models have also done a lot of flip-flopping back and forth on temperatures for the week including the Arctic blast Thursday through Saturday. Just 36 hours ago it was forecasting Friday to be all below zero and now has it teens. It has gone back and forth with each model run.


I suspect the best thing is to take a wait and see approach for now. The clipper could make some subtle changes to the overall pattern which could be good for us wanting snow. I think my call will for the snow amounts will come Sunday evening sometime. Until then, I just keep hoping.

Saturday Clipper

The Saturday clipper remain on track for an inch of snow. Temperatures will remain cold throughout the weekend too.

The models have settled down on the storm next week and have trended southeast and weaker. There also has been some signs of mixing with the thickness value borderline for some of the event on Tuesday. It is still early to make any final call so keep checking back over the weekend for updates.

School Delay Bust & What's Next...

I busted with my suggestion about a school delay for Thursday. I was surprised to see the roads as dry as they were this morning. Oh well...

There are several things to look forward to if you like snow. There is a clipper system moving down over the weekend making a little bit of snow on Saturday. Likely trace amounts to an inch. Nothing to get excited about.

The real deal could be next week with a system moving in late on Monday into Tuesday. This system could be a real snow maker with cold Arctic air in place and moisture coming up from the gulf. Forecast models have been pretty consistent with an inch or more of precipitation would could translate into 10 inches or more of snow.

That is followed by very cold weather for the period Thursday through Saturday.

Snow/Rain Line

It is close to our area. Expect a change to all snow by 11PM.

Ugly Forecast

The warm temperature is melting the snow away. Some light rain will begin around the early evening before changing to all snow a little after midnight. About 1/10 if an inch of rain plus 1/2" of snow accumulation. While not much of of either type of precipitation, the temperature will be well below the freezing mark by the Thursday rush hour so expect a slick trip in. (I have moderate confidence in a two hour delay for area schools.)

Rain & Snow Mix

Wednesday afternoon will bring us rain ahead of the approaching cold front. The rain plus warm temperatures will likely melt our current snow cover. The rain will change over to snow in the evening as temperatures plunge.

The plunge to the low 20's has the chance to flash freeze the rain and melted snow making for slick conditions. It could make the Thursday morning commute quite treacherous.

School Delay & Our Next Snow Event...

The 2 hour delay for area county schools this morning seems warranted. Very slick roads and I hear numerous minor accidents/slide offs on the scanner.

Our next snow event will start as rain on Wednesday and turn to snow Wednesday night. It is a clipper system so it won't track northwest. Expect 1 to 2 inches depending on timing of the cold front.

Missed The Snow Delay Call

I mised the snow delay call this morning. The snow and wind overnight didn't come about as planned. Oh well, maybe I can pull one out on Thursday. *wink*