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November 11-12 Cold Front/Lake Effect Rain/Snow

Thunder Road

By Thunder Road,
in Lakes/Ohio Valley

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Hoosier

Hoosier

Posted
Posted

Here's IWX's in-house model's precip total (NAM initiated). I have found it to be fairly accurate with trajectory for Lake MI LES events.

IWX In-house 112013.png

Interesting...some of the globals/lower res models have been showing something like that. I don't quite understand the eastward placement given the progged trajectories over the lake and I'd have to think that land breeze influences may shift the band more toward mid lake.

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Geos

Geos

Posted
Posted

I know I'm going to get roasted for saying this, but the NAM does better with LES than the GFS.

 

I plan my LES chases based on the NAM and it never fails when within 48 hours.

 

 

attachicon.gifnam_namer_084_precip_ptot.gif

 

Actually I think that as well. It is a higher resolution model. If I didn't have to drive through Chicago, I'd go chase the LES too.

 

@ Hoosier's comment regarding trajectories and placement. You would think the placement on the NAM would actually be in the zone I marked below on the map, not over By Berrien County. - at least not at first.

I think T-Road is going to get blasted!

 

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Thunder Road

Thunder Road

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Interesting...some of the globals/lower res models have been showing something like that. I don't quite understand the eastward placement given the progged trajectories over the lake and I'd have to think that land breeze influences may shift the band more toward mid lake.

 

I'm trying to look at everything without the weenie goggles on, but I have to agree.  The wind shifts to more NNW by around 18z, but that's accompanied by a bit of drying, so it really seems that Porter County is going to be in the bullseye.

 

I have to be up at 3:45 a.m. Tuesday so that I'm ready to start briefing school districts at 4:30.  Since I don't usually go to bed until around 2 anyway, I'll probably just stay up and enjoy this.

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mempho

mempho

Posted
Posted

I happen to be coming in to Dayton for work on Monday afternoon.  I realize that Dayton is not in an LES zone but I'm wondering if a short drive might put me in a favorable location.  I've gotta stay in Columbus on Monday night, work on Tuesday and Wednesday during the day.  I realize that instabilities might be extreme for some favored locations.  Do any of you have any advice for someone trying to work in an LES chase during this time or does my timing/location not work out for this?  Perhaps some of you know a good orographic location within a couple of hours of the Dayton/Columbus region?

 

 

Also, forgive me if I ask this incorrectly, but, is there not going to be a time when the Huron/Erie double band will come into play over north-central Ohio?  It looks like there might be some good north-south orientation from over Lake Michigan but I'm not seeing that come up on the QPF maps for the same axis over Huron-Erie- but I might be looking at the wrong time frame.

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OHweather

OHweather

Posted
Posted

I happen to be coming in to Dayton for work on Monday afternoon.  I realize that Dayton is not in an LES zone but I'm wondering if a short drive might put me in a favorable location.  I've gotta stay in Columbus on Monday night, work on Tuesday and Wednesday during the day.  I realize that instabilities might be extreme for some favored locations.  Do any of you have any advice for someone trying to work in an LES chase during this time or does my timing/location not work out for this?  Perhaps some of you know a good orographic location within a couple of hours of the Dayton/Columbus region?

 

 

Also, forgive me if I ask this incorrectly, but, is there not going to be a time when the Huron/Erie double band will come into play over north-central Ohio?  It looks like there might be some good north-south orientation from over Lake Michigan but I'm not seeing that come up on the QPF maps for the same axis over Huron-Erie- but I might be looking at the wrong time frame.

Usually intense lake effect doesn't make it nearly as far south as Dayton or Columbus. Mansfield, OH is in a hillier region and typically sees some lake effect snow in a NNW flow, but I wouldn't expect more than 1-3" there, even if that is a bit of a local max. You'd either have to drive to NW IN or extreme NE OH to get the really good stuff.

 

As for the Huron-Erie connection, one should form in this event and a lot of the models show it at peak intensity on Tuesday during the day and lingering into Tuesday night before ending Wednesday morning. If the flow was more true northerly this connection would put possibly decent snows into the Cleveland and Akron metros, but with some westerly component to the winds I'd expect this connection to remain farther east than that. There will probably be at least half decent snows over extreme NE OH with this setup but it will be east of Cleveland and Akron and a really long drive from your location.

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Thunder Road

Thunder Road

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Chicago AFD getting pretty bullish, calling for 6-12".  Interesting that this forecaster identified 6z-18z as the time frame, since I'm seeing LES starting possibly as early as 3z but probably moving out of the LOT CWA between 12z and 15z. 

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
320 AM CST SUN NOV 10 2013

...

THE MORE SIGNIFICANT WEATHER SITUATION WILL BE THE POTENTIAL LAKE
EFFECT SNOW OVER NWRN INDIANA.  AS THE ARCTIC HIGH SETTLES OVER THE
MISSOURI VALLEY VERY COLD AIR WILL OVERSPREAD THE RELATIVELY WARM
LAKE MICHIGAN WATERS AND THE PATH OF THE CENTER OF THE HIGH WILL
ALSO SET UP A PERSISTENT NORTHERLY FETCH OVER THE FULL LENGTH OF
LAKE MICHIGAN.  THE HIGHER RESOLUTION MODELS LOCAL MESOSCALE MODELS
AND THE OPERATIONAL NAM ALL DEVELOP A PERSISTENT LAKE EFFECT PLUME
EVEN THE LOWER RESOLUTION GLOBAL GFS/ECMWF ALSO HINT AT LAKE PLUME
DEVELOPMENT.  MODEL SOUNDINGS SHOW A RELATIVELY SIGNIFICANT AMOUNT
OF LOW LEVEL INSTABILITY AND SFC CONVERGENCE.  CURRENTLY FEEL THAT
THE ELEMENTS ARE COMING TOGETHER FOR THE POTENTIAL AN EARLY SEASON
HEAVY LAKE EFFECT SNOW EVENT FOR NWRN INDIANA.  WILL HOLD OFF ON ANY
TYPE OF HEADLINE FOR NOW GIVEN SOME UNCERTAINTY AS TO WHERE THE
PLUME WILL ULTIMATELY SET UP...BUT GIVEN THE FORECAST INSTABILITY
PROFILES AND ASSOCIATED LOW LEVEL OMEGA FIELDS...AS WELL AS THE
SYNOPTIC SETUP OF THE ARCTIC HIGH SETTLING OVER THE CNTRL
CONUS...THERE IS THE POTENTIAL FOR A LAKE EFFECT PLUME TO PRODUCE 6
TO 12 INCHES OF SNOW FROM 06-18Z TUESDAY WITH PERIODS OF 2-3 INCH
PER HOUR SNOWFALL RATES.  WHILE THE MODELS HAVE BEEN STEADILY
CONVERGING ON THIS SCENARIO AND HAVE BEEN HANDLING THE COLD AIR
OUTBREAK VERY WELL...THERE IS STILL A HIGH BUST POTENTIAL GIVEN THE
VERY MESOSCALE NATURE OF LAKE EFFECT SNOW PLUMES.

...

KREIN

IWX a lot more bearish, but at least also mentioning that Porter seems to be the best spot to be right now:

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 442 AM EST SUN NOV 10 2013

THE MAIN CHALLENGES THIS PERIOD CONCERN THE TIMING OF THE ARCTIC
FRONT MONDAY INTO MONDAY EVENING AND SUBSEQUENT LAKE EFFECT SNOW
SHOWERS. THE GFS CONTINUES TO BE A LITTLE FASTER WITH THE FRONT THAN
THE NAM...AND AS A RESULT BRINGS THE COLD AIR IN QUICKER WITH A
FASTER CHANGE/OVER TO SNOW SHOWERS. HAVE LIGHT SNOW ACCUMULATIONS
OVER MAINLY FAR SOUTHERN LOWER MICHIGAN BEGINNING EARLY MONDAY
EVENING AS SURFACE TEMPERATURES FALL BELOW FREEZING AND AS LOW LEVEL
THICKNESSES FALL UNDER 1300 METERS. CONCERN FOR THE POSSIBILITY FOR
HEAVY LAKE EFFECT SNOW GIVEN LONG LAKE FETCH AND COLD AIR SUFFICIENT
FOR LAKE EFFECT SNOW SHOWERS. HOWEVER...NAM NOT IMPRESSIVE WITH
INVERSION HEIGHTS. ALSO...BELIEVE VERY STRONG SUBSIDENCE ABOVE THE
UPPER FRONT WILL HINDER SNOW SHOWER DEVELOPMENT. IN ADDITION...NAM
SUPPORT FOR WINDS BECOMING NORTH/NORTH ALLOWING THE HEAVIER LAKE
EFFECT SNOW SHOWERS TO OCCUR WEST OF THE FORECAST AREA. FOR NOW...
HAVE THE HIGHEST SNOWFALL OVER LAPORTE COUNTY WITH 2 TO 3 INCHES FOR
THE EVENT. OTHERWISE...ONGOING TEMPERATURES APPEAR ON TRACK...WITH
THE COLDEST MORNING WEDNESDAY MORNING.

&&
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ValpoVike

ValpoVike

Posted
Posted

LOT has Valpo gridded for 5-9", just northeast of town 6-10".  IWX has Westville gridded for ~2".  Interesting disparity. 

 

Fairly typical to have LOT and IWX with such disparities between eastern Porter and western LaPorte in LES events.  I have noticed this for years, but I have also noticed that LOT tends to be right more often.  LOT also seems to be more conservative on LES than IWX.

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IWXwx

IWXwx

Posted
Posted

Yep. Won't amount to much but one of those things that could be briefly exciting.

 

Yeah, the first measurable snow is always exciting, especially if we can get a brief shot of +SN. It's also exciting on the roadways, as people forget how to drive on slick roads.

 

I'm guessing that LOT will hoist a Lake Effect Snow Watch at least for Porter county in the next cycle or two. Could also probably justify one for Jasper and Lake (at least east of I-65) but not sure they will go that route.

 

I see from Keener's post above that IWX's in-house is still showing the brunt of the band in Laporte Co., yet their grids are showing only a couple of inches of accumulations. They must also think that Porter Co. will be the bullseye.

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Hoosier

Hoosier

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Posted

Yeah, the first measurable snow is always exciting, especially if we can get a brief shot of +SN. It's also exciting on the roadways, as people forget how to drive on slick roads.

I see from Keener's post above that IWX's in-house is still showing the brunt of the band in Laporte Co., yet their grids are showing only a couple of inches of accumulations. They must also think that Porter Co. will be the bullseye.

LAF area drivers are seasoned winter weather experts...I'm sure there won't be any problems.

IMO, if this thing busts one way or another, it's more likely to bust west, meaning that more of Lake county would get in on the heavy amounts. 925-850 mb flow turns like 005-020 for quite a few hours.

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Thunder Road

Thunder Road

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ARW has 0.75"+ by 12z Tue, and its sim reflectivity shows precip continuing past that time:

 

11-12-13ARW1.gif

 

Interestingly enough, the NMM keeps the band in SW MI through the end of the period, but still brings 0.25" from the cold front and enough from LES showers to get mby to 0.50" by 12z.

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Hoosier

Hoosier

Posted
Posted

ARW has 0.75"+ by 12z Tue, and its sim reflectivity shows precip continuing past that time:

11-12-13ARW1.gif

Interestingly enough, the NMM keeps the band in SW MI through the end of the period, but still brings 0.25" from the cold front and enough from LES showers to get mby to 0.50" by 12z.

Don't know what to make of these hi-res runs. They don't make a lot of sense conceptually.

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