Intense Autumn Storm System Arrives Tomorrow in the Great Lakes

I’m not going to try to be particularly clever in writing this post. Instead, I’m going to throw a bunch of weather maps and a few soundings at you and let them tell the story.

I will say that the weather system that is shaping up for late tonight on into Wednesday for the Great Lakes has the potential to be of historic proportions. In terms of sea level pressure, I’ve seen a number of comparisons to the great Armistice Day Storm of November 11, 1940. However, there are two significant differences: this storm is a bit earlier in the year, and the forecast pressure has been consistently and significantly deeper. The Armistice Day storm dropped to 979 millibars; this one may be in the 960s. In other words, we may see a record-setting barometric pressure with this system.

The bottom line is, this thing will be a wind machine like few we’ve ever seen. Here’s the current forecast discussion from the weather forecast office in Grand Rapids, Michigan.

LOW PRESSURE IN THE SOUTHERN PLAINS WILL RACE NWD AND PHASE WITH A
LOW OVER THE DAKOTAS AND RAPIDLY DEEPEN AS THE UPPER TROUGH DIGS
ACROSS THE UPPER MS VALLEY. THIS WILL LEAD TO VERY STRONG DYNAMICS
ALONG THE TRAILING COLD FRONT LATE TONIGHT. EXPECT STRONG TO SEVERE
STORMS TO DEVELOP ALONG THE FRONT AND RACE EAST. A 70KT LLJ AND
115KTS AT H5 INDICATE IT WON/T TAKE MUCH TO GET SVR WINDS WITH THIS
LINE OF STORMS LATE TONIGHT. A VERY STRONG PRESSURE COUPLET...ON THE
ORDER OF 6MB/3 HRS WILL FOLLOW THE COLD FRONT. THIS WILL LEAD TO
STRONG WINDS DEVELOPING BEHIND THE FRONT. BUFKIT WIND PROFILES SHOW
MIXING INTO THE 55-60KT LAYER AT 2K FT. IT IS LOOKING INCREASINGLY
LIKELY THAT WE/LL SEE SUSTAINED WINDS AROUND 35 MPH AND WIND GUSTS
OVER 50...AND CLOSER TO 60 ALONG THE LAKE SHORE. AS SUCH WE EXPANDED
THE HIGH WIND WATCH TO COVER THE ENTIRE CWA.

WINDS WILL DECREASE TUESDAY NIGHT AS MIXING WANES...BUT WILL
INCREASE CONSIDERABLY AGAIN WEDNESDAY. THIS IS A SLOW MOVING STORM
THAT WILL RESULT IN A PROLONGED WIND EVENT FOR THE CWA.

I’m not going to add a lot to that, but I do want to mention the possibility of tornadoes during a brief window of time. Hodographs preceding the front curve nicely, with 1 km storm-relative helicity exceeding 300 showing on this morning’s 6Z NAM sounding for Grand Rapids at 17Z tomorrow afternoon. If enough instability develops–and with winds like the ones we’re looking at, it won’t take much–then we could certainly see some spin-ups as the squall line blows through. And if there’s enough clearing to allow discrete storms to fire ahead of the front, chances for tornadoes increase all the more.

With storms rocketing along to the northeast at over 60 miles an hour, the thought of chasing them is laughable. Anyone out to intercept them will have to watch the radar, position as strategically as possible, and then hope for the best. Serendipity will be the name of the game. That game could begin as early as noon here in Michigan, and it looks to be over before 5:00 p.m.

Not the wind, though. That’ll be hanging around for a while.  Batten down the hatches, campers–we are in for one heck of a blast.

Without further ado, here are some weather maps and NAM forecast soundings from this morning’s 6Z run. Click on the images to enlarge them. Just look at that surface low! Pretty jaw-dropping, I’d say.

Forecast maps for 18Z Tuesday, October 26, 2010

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nam-850mb-for-18z-tues
nam-500mb-for-18z-tues
nam-1km-helicity-for-18z-tues


Soundings

kgrr-nam-for-17z-tues

Grand Rapids, MI (forecast hour 17Z)

ksbn-nam-for-16z-tues

South Bend, IN (forecast hour 16Z)

kmie-nam-for-17z-tues

Muncie, IN (forecast hour 17Z)

October 25, 2010 by
Filed Under: Life, Michigan, Nature, Outdoors, Weather Tagged With: , , , , , , , , , ,

Bundling Up for a Michigan Blizzard

As I begin this post, around 5:20 p.m. EST, the KGRR metar shows a temperature of 35 degrees here in Grand Rapids, Michigan. Not far to the southwest, though, closing in on Chicago, northeast Illinois is giving reads of around 20 degrees. The backside of the low pressure system that has brought us a

sfc-tds_mlcape-nam-123110
wintry mix is preparing to bring considerably colder temperatures down upon us, wrapping in from the northwest and west as the low lifts up into Canada.

So far, conditions really haven’t been bad at all, certainly not as bad as the scenario the NWS has painted with a blizzard warning commencing at 1:00 p.m. But I’m sure the weather will worsen; it’s just a matter of time. The guys at the local WFO have the unenviable  task of forewarning the public of potentially lethal winter conditions without coming up looking like goobers when the blob of Jello-O they’ve got to nail to the wall doesn’t entirely cooperate. Predicting severe warm-season weather is tough enough, but forecasting winter weather is a whole different kettle of fish entirely, and my guess is, it’s a harder one to get right.

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Anyway, here’s what’s presently sitting on top of us here in Michigan. The topmost image is a 2200Z map showing current pressure and wind barbs. The bottom one is a level 2 radar grab with metars. Click on the images to enlarge them. They depict conditions at the time of the evening commute, which aren’t too bad; they also indicate what’s on the way, which isn’t too good. We are gonna get socked, methinks. But that’s okay. Lisa and I have got a couple Christmas movies to watch, good beer, plenty of food, the warmth of each others’ company, and the blessing of the Lord’s presence in our humble but comfortable apartment. Really, it doesn’t get much better than this.

December 9, 2009 by
Filed Under: Life, Weather Tagged With: , , , , , , ,

An October Great Lakes Wind Machine

Geeze, is it ever blowing out there! The low pressure system that I’ve been harping about this past week has been moving through the Great Lakes, bringing with it temperatures in the low 70s, rich dewpoints, heavy rain, and wind gusts as high as 48 miles an hour.

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Here’s a grab of the current conditions at 9:15 eastern time. Click to enlarge.

The 980 mb low has nudged off the Minnesota border into Ontario and continues to deepen rapidly as it heads east. You can see the line of storms firing along the cold front all the way down into the Gulf. Mississippi and Alabama got hammered earlier with an outbreak of supercells, but that action seems to have died down now. Not so the wind here in Grand Rapids, Michigan. It began picking up from the south in the afternoon, but it has now veered to the southwest with the passage of the cold front.

Temperatures have dropped over ten degrees over the past hour or so. The KGRR station ob says 58 degrees, but just 60 miles to my east, KLAN is registering 70 degrees.

There won’t be much left of the leaves come tomorrow morning. This system has been typical of a Michigan October–a wind machine that denudes the trees, delivering the coup de grace to the warm season and requiring those of us who live in the Great Lakes to gird our minds for winter. Ugh! These next five months won’t be fun.

October 30, 2009 by
Filed Under: Life, Outdoors, Weather Tagged With: , , , , , ,