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Lake Effect Snow Belts Discussion Thread


TugHillMatt

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Looks like another possible historic event unfolding around here from Thurs-Sat. Haven't had a chance to look at to many models but someone is going to get feet out of this one.

...WIND CHILL ADVISORY REMAINS IN EFFECT UNTIL 10 AM ESTTHURSDAY......LAKE EFFECT SNOW WATCH REMAINS IN EFFECT FROM LATE THURSDAYNIGHT THROUGH FRIDAY EVENING...* LOCATIONS...GENESEE AND NORTHERN ERIE COUNTIES.* TIMING...THROUGH THURSDAY MORNING FOR THE WIND CHILL ADVISORY.  LATE THURSDAY NIGHT AND FRIDAY FOR THE LAKE EFFECT SNOW WATCH.* WINDS AND WIND CHILLS...SOUTHWEST 15 TO 25 MPH...WITH WIND  CHILLS AVERAGING AROUND 20 BELOW ZERO.* SNOW FRIDAY...HEAVY LAKE EFFECT SNOWFALL POSSIBLE WITH SNOWFALL  RATES OVER 3 INCHES AN HOUR.* IMPACTS...BITTERLY COLD WIND CHILLS WILL RESULT IN DANGEROUS  CONDITIONS FOR EXPOSED SKIN. ANOTHER ROUND OF VERY HEAVY LAKE  EFFECT SNOW IS POSSIBLE FRIDAY AND SATURDAY WHICH COULD LEAD  TO VERY DIFFICULT TRAVEL CONDITIONS AND LOW VISIBILITIES.
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Awesome writeup from Buffalo NWS.

 

THE LAKE EFFECT SNOW AMOUNTS WILL EVENTUALLY BECOME SIGNIFICANT BY
THE END OF THE PERIOD. THE 60-72 HOUR CIPS ANALOGS SUGGESTING THE
POTENTIAL FOR SEVERAL FEET OF SNOW OFF BOTH LAKES...WITH THE MOST
SIGNIFICANT TOTALS SOUTH OF BUFFALO AND WATERTOWN. THIS EVENT HAS
THE POTENTIAL TO VERY DISRUPTIVE TO TRAVEL WITH POSSIBLE CLOSURES OF
MAJOR HIGHWAYS...INCLUDING THE NEW YORK STATE THRUWAY AND INTERSTATE
81.

 

AS FOR THE LAKE EFFECT SPECIFICS...

OFF LAKE ERIE...LOW LEVEL FLOW BACKING TO SOUTH SOUTHWEST WILL FOCUS
LAKE ENHANCED SNOWFALL INITIALLY NORTH OF THE BUFFALO AREA. VEERING
FLOW BEHIND THE SHORTWAVE WILL FOCUS A SIGNIFICANT LAKE BAND ON A
SOUTHWEST FLOW INTO THE BUFFALO METRO AREA BY DAYBREAK FRIDAY
MORNING...AS OVER-LAKE INSTABILITY SHARPLY INCREASING WITH
EQUILIBRIUM LEVELS NEARING 10K FEET. COMBINATION OF SNOWFALL RATES
IN EXCESS OF 2 INCHES PER HOUR AND WIND GUSTS OVER 30 MPH WILL MAKE
FOR EXTREMELY DIFFICULT TRAVEL CONDITIONS DURING THE FRIDAY MORNING
COMMUTE. THE BAND WILL LIKELY SWING THROUGH FAIRLY QUICKLY AS THE
FLOW CONTINUES TO VEER TO A MORE WEST SOUTHWEST ORIENTATION BY MID
DAY WITH A SIGNIFICANT LAKE BAND SETTING UP ACROSS THE DISTANT
BUFFALO SOUTHTOWNS AND NORTHERN PORTIONS OF THE SOUTHERN
TIER...REMAINING THERE WELL INTO SATURDAY. ONCE THE LAKE BAND SETS
UP...THE OVER-LAKE INSTABILITY BECOMES EXTREME WITH LAKE INDUCED
CAPES OVER 500 J/KG AND EQUILIBRIUM LEVELS NEAR 12K FEET. THESE
INSTABILITY FIELDS WOULD SUGGEST THE POTENTIAL FOR INTENSE SNOWFALL
RATES IN EXCESS OF 3 INCHES PER HOUR. WINDS GUSTING TO NEAR 30 MPH
WILL RESULT IN SIGNIFICANT BLOWING AND DRIFTING SNOW WITH NEAR
WHITEOUT CONDITIONS. A LAKE EFFECT SNOW WATCH HAS BEEN ISSUED
ACCORDINGLY FOR AREAS EAST OF LAKE ERIE...INCLUDING THE METRO
BUFFALO ALTHOUGH IT SHOULD BE NOTED THAT THE MOST SIGNIFICANT SNOWS
AREA LIKELY ACROSS THE DISTANT BUFFALO SOUTHTOWNS INTO THE WESTERN
SOUTHERN TIER.

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  • 4 weeks later...

Looks like two good chances for appreciable lake-effect next week with two cold outbreaks in rapid succession Thursday and then again Saturday.

 

The GFS has been going bonkers with the signal (hello Dayton?) and now that it's within a week (and pre-truncation) I figured it'd be worth bumping the thread.

 

2015020518_CON_GFS_SFC_SLP_THK_PRECIP_WI

 

Attm, the GFS's handling of the High would result in climo-favored areas to my east cashing in, but it's still 7 days out and there's plenty of time for that to change.   :snowing:  

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Looks like two good chances for appreciable lake-effect next week with two cold outbreaks in rapid succession Thursday and then again Saturday.

 

The GFS has been going bonkers with the signal (hello Dayton?) and now that it's within a week (and pre-truncation) I figured it'd be worth bumping the thread.

 

2015020518_CON_GFS_SFC_SLP_THK_PRECIP_WI

 

Attm, the GFS's handling of the High would result in climo-favored areas to my east cashing in, but it's still 7 days out and there's plenty of time for that to change.   :snowing:  

 

 

This period is definitely worth watching.  I agree that current handling of the high would probably place the focus east of Valpo, but it wouldn't take much of a change to shift it west, and of course any mesolow development could alter the location.

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Holy crap at the weekend setup off of southern Lake Michigan.  The parameters on the 12z GFS are pretty eye popping (delta T in the mid to perhaps upper 20s and pretty high inversion heights).  The signal on the 12z GGEM is pretty impressive, considering we are talking about a global model.

 

 

post-14-0-71896400-1423505940_thumb.gif

 

Still have the Thursday event, but barring a change in the models (possible with it being several days out), the weekend one looks like it has higher potential at this point.

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Holy crap at the weekend setup off of southern Lake Michigan.  The parameters on the 12z GFS are pretty eye popping (delta T in the mid to perhaps upper 20s and pretty high inversion heights).  The signal on the 12z GGEM is pretty impressive, considering we are talking about a global model.

 

12z GGEM for Saturday/Sunday.

 

 

 

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12z GGEM for Saturday/Sunday.

 

attachicon.gifggem 132.png

 

attachicon.gifggem 138.png

 

attachicon.gifggem 144.png

 

 

Thanks for those.

 

Something to watch will be the DGZ/flake size as these really cold airmasses sometimes aren't that favorable in that regard.  In this case, the DGZ will be very low/near the ground, so how much the omega intersects will be important.  It certainly has my attention, but my bar is going pretty high in terms of chasing, especially since I just did so for the Feb 1 storm.  :guitar:

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Temps still in the upper 30s to 40-ish over southern Lake Michigan. Can you say explosive?

attachicon.gifmswt-00.gif

Wow yeah really can't see any downsides thermodynamically. Pretty much off the charts. Wind speeds could bit a bit too strong initially to maximize dendrite size but the winds would also likely result in true blizzard conditions in the band. Really impressive signal. Wednesday night into Thursday is nothing to sneeze at either. Big question for us here at LOT with the first event is wind direction and whether focus is Porter County or LaPorte. Right now we're leaning extreme northeast Porter and points east.

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Wow yeah really can't see any downsides thermodynamically. Pretty much off the charts. Wind speeds could bit a bit too strong initially to maximize dendrite size but the winds would also likely result in true blizzard conditions in the band. Really impressive signal. Wednesday night into Thursday is nothing to sneeze at either. Big question for us here at LOT with the first event is wind direction and whether focus is Porter County or LaPorte/Berrien. Right now we're leaning extreme northeast Porter and points east for heaviest, but much of Porter could still get into decent advisory type snows.

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Wow yeah really can't see any downsides thermodynamically. Pretty much off the charts. Wind speeds could bit a bit too strong initially to maximize dendrite size but the winds would also likely result in true blizzard conditions in the band. Really impressive signal. Wednesday night into Thursday is nothing to sneeze at either. Big question for us here at LOT with the first event is wind direction and whether focus is Porter County or LaPorte. Right now we're leaning extreme northeast Porter and points east.

 

 

Regarding winds, 850 mb winds are progged to be around 50 kts early on this weekend before weakening.  Should see good inland penetration.

 

Thermodynamically, this is pretty much a top of the line setup right now, but it's still 5 days away so we'll see if the models hold.  The few north-ish flow setups I can recall with these kinds of delta Ts and inversion heights produced 1-2+ feet of snow, so there's some good potential.

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Regarding winds, 850 mb winds are progged to be around 50 kts early on this weekend before weakening. Should see good inland penetration.

Thermodynamically, this is pretty much a top of the line setup right now, but it's still 5 days away so we'll see if the models hold. The few north-ish flow setups I can recall with these kinds of delta Ts and inversion heights produced 1-2+ feet of snow, so there's some good potential.

D prog/dt of past few runs of Euro actually grew more impressive with cold punch this weekend but 5 days is certainly a lot of time for things to change and become a bit less favorable. But at this point, soundings are extremely impressive with inversion heights over 10 kft. Inland extent as you mentioned should be good due to the 850 flow. I'd like to look back at AFDs leading up to the big 1/20-1/21/14 lake effect event in Cook and Lake County IN. If I'm not mistaken, that appeared to favor Porter and LaPorte counties initially. Regarding the Wednesday night into Thursday event, the CIPS analogs showed pretty high probabilities of at least 6" amounts in LaPorte/Berrien counties with decent probs into Porter.
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D prog/dt of past few runs of Euro actually grew more impressive with cold punch this weekend but 5 days is certainly a lot of time for things to change and become a bit less favorable. But at this point, soundings are extremely impressive with inversion heights over 10 kft. Inland extent as you mentioned should be good due to the 850 flow. I'd like to look back at AFDs leading up to the big 1/20-1/21/14 lake effect event in Cook and Lake County IN. If I'm not mistaken, that appeared to favor Porter and LaPorte counties initially. Regarding the Wednesday night into Thursday event, the CIPS analogs showed pretty high probabilities of at least 6" amounts in LaPorte/Berrien counties with decent probs into Porter.

 

 

I seem to remember the same thing about the January 2014 event initially favoring areas farther east.  I know it was supposed to be a bit more progressive on the day of (21st) but it hung up/stalled and blasted Lake county.

 

IWX mentioned the flake size being a concern, but they also mentioned increasing ice coverage being a negating factor which I don't really agree with.  There's a lot less ice on the lake compared to this time last year, and the lake had quite a bit of ice during that January 2014 event and it still dumped 2 feet.   

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Temps still in the upper 30s to 40-ish over southern Lake Michigan.  Can you say explosive?

 

 

 

attachicon.gifmswt-00.gif

 

I don't know about you, but 9 F and +TSSN sounds like the ideal Valentine's Day to me!

 

 

Wow yeah really can't see any downsides thermodynamically. Pretty much off the charts. Wind speeds could bit a bit too strong initially to maximize dendrite size but the winds would also likely result in true blizzard conditions in the band. Really impressive signal. Wednesday night into Thursday is nothing to sneeze at either. Big question for us here at LOT with the first event is wind direction and whether focus is Porter County or LaPorte. Right now we're leaning extreme northeast Porter and points east.

 

I've grown more and more pessimistic over my years at Valpo wrt lake-effect, since every good event has just barely missed us.  So with that bias in mind, I'm guessing we squeak out something like 2-4" Thursday morning as the band is organizing and then LaPorte County gets the big totals.  But we'll see.  Contrary to popular belief, more events in my four years have ended up west of where they were modeled than east of.  2/12/12, 1/20/14, 4/14/14 (sorta)

 

 

Regarding winds, 850 mb winds are progged to be around 50 kts early on this weekend before weakening.  Should see good inland penetration.

 

Thermodynamically, this is pretty much a top of the line setup right now, but it's still 5 days away so we'll see if the models hold.  The few north-ish flow setups I can recall with these kinds of delta Ts and inversion heights produced 1-2+ feet of snow, so there's some good potential.

 

If you've got 4WD I'll split the cost of gas/motel/booze.  Not even joking.

 

 

I'd like to look back at AFDs leading up to the big 1/20-1/21/14 lake effect event in Cook and Lake County IN. If I'm not mistaken, that appeared to favor Porter and LaPorte counties initially.

 

Two days out we were in the bullseye.  Hi-res models just kept shifting west and west.  If I remember right, we had a LES Watch out for a whole period or more before Lake County did, and as luck would have it, we ended up only getting a Trace here.

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Euro looked good for mby too.  Doesn't stall it over us as much as the GGEM but still a solid 6 hours, maybe even 9, and with the thermodynamic environment I can't imagine anything less than 3"/hr rates in the band.

 

 

Yeah it should really rip.  The unfortunate thing about these events is that it's so difficult to get the northerly type flow to lock in for an extended period of time, but that's nothing new.  Time is not as much of a hindrance when it's coming down so fast.  I remember somebody reporting like 17" in 4 hours in Griffith during that Jan 2014 event, and this one seems even a bit better thermodynamically.  Besides the outstanding lake-850 mb delta Ts, lake-700 mb delta Ts are shown to be in the mid to upper 30s C, and 30C is sort of a benchmark for heavy snow.

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Regarding the nasty 850mb temperatures on some of the GFS runs, I was curious to see when was the last time DTX sounding station recorded a -26C or -28C or -30C at 850mb. The SPC sounding climatology page showed the minimum 850mb temp was -34.3C on January 17 at 12z on some year at either DTX, MTC, FNT, or TOL (historical soundings for MTC, FNT, and TOL). Minimum for February was -28.5C on February 11 at 00z on some year.  BUF sounding had similar values. So it is very unlikely that DTX will get a -28C or lower on any particular sounding in the near future.

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Yeah it should really rip.  The unfortunate thing about these events is that it's so difficult to get the northerly type flow to lock in for an extended period of time, but that's nothing new.  Time is not as much of a hindrance when it's coming down so fast.  I remember somebody reporting like 17" in 4 hours in Griffith during that Jan 2014 event, and this one seems even a bit better thermodynamically.  Besides the outstanding lake-850 mb delta Ts, lake-700 mb delta Ts are shown to be in the mid to upper 30s C, and 30C is sort of a benchmark for heavy snow.

 

My tractor beam pulls the bands east toward the SW Michigan trail system.

 

I'm mentally willing the band east.... good times out there last winter.

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12z GFS forecast soundings for a point over southern Lake Michigan between 18z Sat and 18z Sun.  This is not modified for lake water temp (don't have access to BUFKIT right now) so it underestimates lake induced CAPE, but you get the general idea

 

 

attachicon.gifle.gif

 

Using a lake temp of 38 degrees I got inversion heights  topping out at 13,300ft at SBN with 1300 j/kg CAPE. Highest 850 delta t's where at GYY at 31C.

 

Besides the winds, the only other downside is the extreme cold limits the DGZ to the near surface.

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Using a lake temp of 38 degrees I got inversion heights  topping out at 13,300ft at SBN with 1300 j/kg CAPE. Highest 850 delta t's where at GYY at 31C.

 

Besides the winds, the only other downside is the extreme cold limits the DGZ to the near surface.

 

Dang

 

As far as flake size, don't want to overlook it but I'm wondering if it will end up being a big issue.  As long as we have some decent lift down toward 925 mb, should at least have some dendrites... and sometimes winds will slacken off in a well-organized band which would help to limit fracturing.

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Not to downplay the weekend, but late Wednesday night into Thursday morning looks really good too. 12z and 18z NAM runs didn't keep the band in Porter County too long, shifting it after about 3 hours or so, while Euro and GGEM linger longer in Porter/LaPorte. With the passage of a surface trough and secondary push of cold air with strong upper wave, lake parameters become very impressive and classified as extreme on BUFKIT. Using a lake sfc temp of 36f, NAM has EL's of about 12kft, 700-800 j/kg of lake induced CAPE and deltas of 23C, while GFS is only slightly less impressive. I think even areas only under the heavy snows for a ~3 hours could easily see up to 6" in that timeframe. Where ever the band lingers, 1'+ totals are possible. Another big issue is the winds, which could gust up to 45-50 mph in the band early Thursday AM. I'm concerned with needing a Blizzard Warning for Porter County if we become confident enough in at least 3 hours of heavy snow for parts of the county.

Sent from my SM-G900V using Tapatalk

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