11/06/05: WIND EVENT

[Robert Dewey]

Since this doesn't relate to an actual chase forecast, and given that it's not "long term" (even though the "long term" thread was about this storm) - I decided to make a new thread.

Other than the obvious threat for strongly forced severe convection / "damaging showers", the threat for a significant synoptic wind event is pretty high. This looks like a classic November wind storm, with the low deepening rapidly over lake Huron between 06Z and 18Z SUN, dropping down to <985MB, a BIG change from earlier runs - so I am still skeptical. The NAM shows a nice secondary 850MB jet axis of 60KNTS in the region of CAA and dry air advection covering much of southern lower MI. NAM also shows sustained SFC winds of 30-35KNTS - with gusts in excess of 50KNTS at 12Z. By 18Z, NAM shows storm force gusts across most of the lakes, spreading into OH, PA, and NY...

If the dry air advecting in is able to scour out cloud cover, and the system deepens as suggested by the NAM, it wouldn't surprise me to see some gusts in the 70-80MPH range. This setup looks very similar to one that occured this time last year, which also yeilded several 60-70MPH gusts.

If this pans out, it would definitely take the rest of the leaves off the trees...

EDIT: Nope, I was wrong - no 90MPH wind gusts... Here is the data from that event:

OTISVILLE 72 MPH 130 PM PATIO FURNITURE/TRASH CANS ETC.

SHELBY TWP 69 MPH 400 PM LARGE TREE BRANCHES DOWN

ROCHESTER HILLS 67.5 MPH 400 PM ROOF DAMAGE/SMALL TREES DOWN

TROY 63.9 MPH 400 PM LARGE TREE & LARGE BRANCHES DOWN

KIMBALL TWP 62 MPH 420 PM

CLINTON TWP 59 MPH 325 PM A BUSINESS LOST PARTS OF ROOF

SALINE 58 MPH 245 PM

BELLE ISLE 57 MPH 239 PM

DRYDEN XX MPH 347 PM NUMEROUS TREE BRANCHES DOWN

PORT HURON XX MPH 330 PM LARGE TREE & 2 LARGE LIMBS DOWN

FAIRGROVE TWP XX MPH 220 PM TREE SNAPPED/LARGE BRANCHES
DOWN

FLUSHING XX MPH 230 PM POWER LINES DOWN ACROSS ROAD/SIDING RIPPED OFF HOUSES

NOTE: THE LAST 4 REPORTS CAME IN WITHOUT WIND SPEEDS.

 

[Robert Dewey]

Latest 00Z GFS and GEM models are in, and they are nearly identical to the NAM... Looks like a classic Witch of November is setting up

 

[Joel Wright]

Well, it definitely looks like the GFS was right all along. The NAM is just plain sucking lately. It was almost completely worthless forecasting this storm...

It looks like this one will bomb pretty nicely. With every run it seems to be forecasted a little stronger each time. Looks like a nice synoptic wind event for the eastern great lakes on eastward.

Unfortunately for us further west, it will just be in the developmental stage here, so not much more than a weak rain event for us. It'll be interesting seeing it all come together though.

I guess I won't be burning leaves this afternoon. :wink:

 

[Jeremy Lemanski]

if i have time tomorrow i'm going to see about driving over to saginaw bay, the eastern shoreline, with my camera and hand held anemometer and see what i can find. If the wind can be a little more Northwesterly then what is currently predicted, it would allow for miles and miles of open water for the wind to cross, piling up waves on the NW facing shoreline of huron county and thus causing some massive waves.

 

[Robert Dewey]

Things still look pretty much on track... The models have been getting stronger with each run, and the NAM is now slowing down and is more in line with the GFS.

The 06Z NAM had mixing layer heights climbing to nearly 5K FT during the early afternoon, with 65-70KNTS widespread between 12Z and 21Z. This system deepens pretty quickly, so even if strong winds in the mixing layer were absent, we'd still be looking at advisory criteria winds at the SFC. The latest 12Z NAM is now even stronger than previous runs, giving more credibility to the event that should unfold.

DTX has storm warnings in effect for the lakes, and a high wind watch for all of our area... If the NAM verifies, sustained winds of 40-50MPH with frequent gusts to +70MPH would be very likely between 09Z/12Z and 21Z/00Z tomorrow...

 

[Robert Dewey]

Been getting frequent gusts to 65MPH... Large tree is down on my neighbors pool (I'll get pics later). I hear the sound of chain saws right now (for another tree that's down) - though I think I would personally wait until the storms over to be out cutting trees in a yard that has many more trees ready to come down.

 

[Brett Adair]

Originally posted by rdewey
Been getting frequent gusts to 65MPH... Large tree is down on my neighbors pool (I'll get pics later). I hear the sound of chain saws right now (for another tree that's down) - though I think I would personally wait until the storms over to be out cutting trees in a yard that has many more trees ready to come down.

Stay safe. Robert. Truely a large outbreak has taken place across a large chunk of the OH/TN Valley area.

 

[rdale]

There's no outbreak at all up here... Still questioning the watch box for Michigan this morning, and really questioning the SVR for Monroe & Wayne Co. But these are just synoptic winds.

 

[Robert Dewey]

Yeah, no convection here... I was just referring to the synoptic winds as a "storm". It's still very bad here... Power flashed a few times, several large trees down, and I even seen a piece of sheet metal (ouch) airborn... This has to be one of the worst synoptic/non-convective wind storms I have witnessed for this area in quite some time. It's really roaring something fierce, you can't even talk outside when it kicks up...

I suspect the strongest of the winds are upon us and should remain for the next couple of hours before starting to back off some.

 

[nickgrillo]

This brings up a interesting question I've had... In cases like this, with non-convective synoptic wind events - if even a shower/thunderstorm pops up... Why not issue a SVR for it? Sort of needless since it's happening already (I think DTX has done it in NOV 03 during the big non-convective wind event with 70-100MPH gusts) -- but it could be useful to some, perhaps.

 

[rdale]

I'd say because it's not useful to most... Remember setting off a SVR means that your life is in danger. (Or it is supposed to.) If winds have been gusting to 55mph all day, and now may gust to 60, is it really worth interrupting the Lions game for? (Guess that depends on how they are playing ;> )

If it doesn't add value to the event - don't do it.

 

[Robert Dewey]

In addition, the high wind warning covers winds in excess of 58MPH anyway. That's why it's a warning (versus an advisory) - it means there is some threat to your life. To give people plenty of lead time, there was a high wind watch 24 hours prior to the actual event...

I think the highest gust here has been around 70MPH, with frequent 55-65MPH gusts. Our elevation in Rochester Hills is slightly higher than other places... Plenty of power outages and stuff, and a big hassle if you're driving (especially a van).

 

[Robert Dewey]

Here's the photo from one of the trees that came down (it's roughly 13 inches in diameter, and about 35 feet long):

 

[Joel Wright]

Damn. The storm definitely got wound up pretty good by the time it left the great lakes.

I measured a massive 29mph wind gust here, which defoliated a few leaves from my trees.

The weather here in NW IL is just oh so exciting.... :roll: