sbnwx85

Mesoscale Discussion 0083 NWS Storm Prediction Center Norman OK 0917 AM CST Mon Jan 22 2024 Areas affected...portions of eastern/northeastern IL...northern IN...far southern MI and far northwest OH Concerning...Freezing rain Valid 221517Z - 221915Z SUMMARY...Light to moderate freezing rain is expected through the morning hours with rates of 0.01-0.03 in/hr possible. Some mixed-phase precipitation is also possible early. DISCUSSION...As of 15 UTC, regional radar mosaic imagery and surface observations showed a broad area of light to moderate wintry precipitation across parts of northeastern IL. Over the last hour, automated reports of unknown precipitation type and freezing rain have gradually become more numerous as the precipitation has expanded over an air mass with surface temperatures in the mid to upper 20s F. Driven primarily by low-level warm advection, light to moderate precipitation is expected to continue to move east/northeast this morning. Light snow has been observed across parts of southwest lower MI and northwest IN. However, observed and modified model soundings show an elevated warm nose of 1-2 C between 1-2 km AGL will gradually advect northeastward over the next few hours. While some snow and sleet are possible ahead of the main area of precipitation, gradually deepening of the elevated warm layer to near 600-800 m will favor a transition to predominately freezing rain. Rain rates of 0.01-0.03 in/hr are possible above favorable surface temperatures for rapid ice accretion. The most likely corridor for impactful freezing rain appears to be from northeastern IL into northwest IN and far southwest lower MI through this morning. Hi-res CAM guidance has been poor thus far in handling the evolution of the precipitation field. While low-level warm advection may wane slightly through the day, observed low and mid-level ascent appears strong enough to continue to support precipitation into the early afternoon. Given the cold surface temperatures and melting layer aloft, freezing rain appears likely. ..Lyons.. 01/22/2024 ...Please see www.spc.noaa.gov for graphic product...

Freezing drizzle already in South Bend. Advisory start time has been pushed up to noon.

Fascinating insight into your world as always @RCNYILWX thanks for sharing! I saw in the IWX media briefing there’s potential for wind gusts to 20 mph and that led me to believe there would be an increased risk of outages. But that appears to be in the early stages of this event before winds decrease.

LOT and IWX current forecasts are definitely Ice Storm Warning criteria. As long as mode trends hold I expect they pull the trigger around Noon on areas forecast to get more than 1/4” of ice.

IWX increased ice forecast a bit. Concerns about how quickly we get above freezing. LONG TERM...(Monday through Saturday) Issued at 337 AM EST Sun Jan 21 2024 Ahead of milder weather later this week, a wintry mix is still expected to develop Monday and persist until temperatures rise above freezing some time early Tuesday. Given the very cold conditions at the onset of the precipitation, surface/ground temperatures are likely to lag warming air temperatures for a few to several hours and allow extra time for ice to accumulate. Widespread model agreement prevails with temperatures rising above freezing over the entire area by noon. Thermal soundings are very limited with any snow (too warm aloft) and sleet (virtually no cold layer at the surface). Given the above, have increased ice accumulations from around 0.05" in the southeast (Lima) to around 0.20" west of Highway 31. Temperatures will stay much above normal through the rest of the week given a very strong positive anomaly (per CPC) over more of North America. CIPS analogs also show a 95% chance for temperatures to be above normal early next week.

For those interested in the snow aspect of the storm. NAM is probably showing its warm bias?

Seems like this will be more of a nuisance event, but will cause issues on the roads. A tenth of an inch seems like a good bet across areas that see ice. It will be interesting to see how long freezing temps hang on around the snowpack and could lead to a little more icing. I’m not posting the GDPS because it’s an outlier but it shows a much more significant icing event across Central Indiana and Illinois, sleet across I-80 and snow north of that.

February will be rockin’ (with thunderstorms)

Just got in to the Chicago suburbs. Took the Toll Road in and hoo boy was that a slow go through LaPorte County. Even though I was focused on the road and it’s night, I can tell you it was the most snow I’ve ever seen on the ground.

3.5” of LE today so far. Nearing a foot of snow depth.

Snow confirmed.

It’s about to snow it’s ass off.

Nothing yet. But the band is shifting slowly this way. Could end up with half a foot before it shifts back to the west.

We’re getting some unofficial reports in our newsroom of 2 feet of snow in Michigan City. 19” in New Buffalo.

Neat to see the lake effect band setting up as the system snow moves through.

The HRRR scoots the lake effect band further toward South Bend Friday afternoon/evening before shifting back west. Would cut down on huge totals in any one location but "spread the wealth" over a slightly wider area.

At this point thinking 1-2” from the system tonight. We’ll see how much the lake effect wobbles east. WSW calls for 4-8” in South Bend.

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Picked up 2.7” overnight from round one. Now have an 8” snow depth. That lake effect band is going to mean business. I’m supposed to travel to the Chicago suburbs Friday night to be at a funeral on Saturday morning. It’s going to be an interesting trek through LaPorte County.

IWX hoists Winter Storm Watch for several counties for the lake-effect. I suspect LOT will do the same for at least Porter County. IWX says Northern LaPorte and Southwest Berrien Counties are favored to see at least a foot of snow.

Anecdotally, I've found it's hard for the globals sometimes to pick up on significant lake-effect signals and both GFS and Euro are spitting out 10+ inches in the Porter/LaPorte County areas for Firday. When it gets into range, the HRRR is gonna spit out like 30" totals if the band stays somewhat stationary lol

February will be rockin’.

Decent single-band lake response somewhere in NW IN into N IN/SW MI, too.

Calling it a storm total of 6.8”. The lake saved this one for me. There are two clear layers of snow: 3” of hard, frozen snow underneath about 4” of fluff.