Next Week Lake-Effect

[ayuud]

Everything still appears to be on track for this upcoming event, and I still believe the higher terrain south of BUF (particularly in Chautauqua County) is in for a very snowy period especially from late tomorrow into Tuesday. The latest high resolution WRF is actually depicting a QPF maximum of 2.57" over Erie County PA!! I totally agree with LEK...some spots along the Chautauqua Ridge could reach 40" with this event, just spread out over a much longer duration than the recent event in the Buffalo south towns.

Another interesting thing to take note of: this morning's WRF is depicting a Georgian Bay streamer making it all the way down into the Niagara Frontier on Monday...allowing for the possibility of a secondary QPF maximum somewhere in the IAG-BUF corridor. Many of us have noted the similarities between this upcoming event and the event that occurred at the beginning of last January...and last January's event brought surprisingly heavy snowfall totals (over 30") to Niagara Falls, which was grossly underestimated by the computer models at that time.

Trying to forecast the placement of a razor-thin Georgian Bay streamer more than 12 hours in advance is pretty much an exercise in futility...but just because this will be an NWF event doesn't mean locations on the Niagara Frontier can't receive +SN as well. We'll need to watch for this.

Hope that verifies

[CNYWxGuy]

12z NAM has really increased the QPF across CNY from previous few runs. Even brings .50-.75 into Northern Tioga-Broome now, possible Finger Lake enhancement?

[kulaginman]

Good stuff guys! I posted in another thread that 12z NAM came in further south (wrt the second retrograder) and the GFS has followed suit. Certainly provides additional chances for synoptic wrap around, along will seeding from above, for the "underneath" LES.

Justin, I recieved nearly 40" over 4 days in Liverpool from last year's Jan event....And, although it doesn't seem "right" to make a similar call, I certainly think this event has an opportunity to verify as such over some locations in C/W NY.

The 4km WRF actually has two QPF maximums downwind of Lake Ontario through 00z Wednesday: 1.53" just south of SYR, and 1.59" near the Oswego/Jefferson/Lewis county junction. My only real concern for your area is that the flow may be too northerly to establish a great connection to the upper lakes...so Lake Ontario may have to do all the work for the majority of the event. Not that Lake Ontario is incapable of producing big snows on its on (LOL)...but that could mean the difference between a 20-30" event and a 40"+ event.

[kulaginman]

Then again, Lake Ontario may get into the deeper synoptic scale moisture associated with the retrograding storm in southeast Canada on Tuesday...so that could make up for the lack of a connection to the upper lakes (think seeder-feeder). Regardless, this will be a big event for many locations from Chautauqua County to the Tug Hill and a lot of places in between.

[Andyace]

Then again, Lake Ontario may get into the deeper synoptic scale moisture associated with the retrograding storm in southeast Canada on Tuesday...so that could make up for the lack of a connection to the upper lakes (think seeder-feeder). Regardless, this will be a big event for many locations from Chautauqua County to the Tug Hill and a lot of places in between.

Am I reading that map right for parts of northern Oneida .50 liquid ?

[WNYLakeEffect]

Here's an example of an early season NW flow event with a Huron Connection. It starts with synoptic snow and transitions to LES by about 8Z.

http://i554.photobuc...if?t=1291492384 >>>6.5mb file

http://www.erh.noaa....6/c/stormc.html

The event had the potential to put down 24-36" had shear not disrupted it so quickly. Maximum totals were in Sherman and Jamestown with 18-20". I don't have totals for that time (and can't really remember it well), but the super Huron band sat over my area for at least 3 hours.

[LakeEffectKing]

Then again, Lake Ontario may get into the deeper synoptic scale moisture associated with the retrograding storm in southeast Canada on Tuesday...so that could make up for the lack of a connection to the upper lakes (think seeder-feeder). Regardless, this will be a big event for many locations from Chautauqua County to the Tug Hill and a lot of places in between.

On a 310 flow or greater, rates rarely exceed 1"/hr......unless we have a very light BL wind (more residence time over shorter fetch), or seeding (as you mentioned) from synoptic "flakes" falling through the LES boundary, which for some time, it looks we will have. Last year our snowfall increased considerably as channeled vorticity advection took place across the lake, with it's corresponding precip shield originating from the N. Atlantic. Interesting stuff to say the least! I think the ratios will be pretty high and get higher until the very end of the event....which may lead to an average of 20-25:1 type stuff, particularly over Erie's snowbelts.

[NorEaster27]

What a great LES setup for Ithaca with possibly FLES all next week. Really makes me miss my college days

[LakeEffectKing]

What a great LES setup for Ithaca with possibly FLES all next week. Really makes me miss my college days

This time of year is great for such phenomena....but honestly, much of the FL's effect snows are driven not so much by added moisture from the FL's themselves, but by the topographical (aided convergence in the valleys) and orographic (hills down wind on southern shorelines) effects. Even when the majority of the lakes are mostly frozen, local convergence aids organization, (what would otherwise be "dieing"), of the bands off Ontario.

[Trent]

I'll be content to see 5" out of this setup, it seems the 270 flow doesn't exist this season. I'm actually curious to see just how much falls south of Lake Erie.

Yeah, CLE just put up watches for 10-20" for Cleveland and points north and east. There's always a very sharp gradient over the city here, with the eastern suburbs generally getting more than double the snow of us on the western shore.

[CNYWxGuy]

Hot off the press from NWS Buffalo...

URGENT - WINTER WEATHER MESSAGE

NATIONAL WEATHER SERVICE BUFFALO NY

342 PM EST SAT DEC 4 2010

CHAUTAUQUA-

INCLUDING THE CITY OF...JAMESTOWN

...LAKE EFFECT SNOW WATCH IN EFFECT FROM SUNDAY AFTERNOON THROUGH MONDAY EVENING...

* LOCATIONS...ALONG THE CHAUTAUQUA RIDGE AND ESPECIALLY SOUTHWEST OF CHAUTAUQUA LAKE.

* TIMING...SUNDAY AFTERNOON THROUGH MONDAY EVENING.

* ACCUMULATIONS...6 TO 10 INCHES...AS MUCH AS A FOOT SOUTHWEST OF CHAUTAUQUA LAKE.

* WINDS (OPTIONAL)...NORTHWEST TO WEST WIND 20 TO 30 MPH WITH GUSTS TO 35 MPH MAINLY DURING SUNDAY EVENING AND NIGHT.

* VISIBILITIES (OPTIONAL)...LESS THAN 1/2 MILE AT TIMES ALONG THE NYS THRUWAY FROM DUNKIRK/FREDONIA TO RIPLEY AND THE PENNSYLVANIA LINE.

* IMPACTS...PERIODS OF VERY HEAVY SNOW...BLOWING SNOW AND SEVERE IMPACT ON DRIVING CONDITIONS ON THE NYS THRUWAY...SOUTHERN TIER EXPRESSWAY AND ROUTE 60 FROM FREDONIA TO JAMESTOWN.

* FORECASTER CONFIDENCE...DEPENDENT ON THE UPSTREAM CONNECTION TO LAKE SNOW FROM LAKE HURON...INITIALLY STARTING IN CHAUTAUQUA COUNTY AND SLIDING SOUTHWESTWARD TO NORTHWEST PENNSYLVANIA AND NORTHEAST OHIO.

[CNYWxGuy]

Updated HWO from NWS BGM...

HAZARDOUS WEATHER OUTLOOK

NATIONAL WEATHER SERVICE BINGHAMTON NY

353 PM EST SAT DEC 4 2010

NORTHERN ONEIDA-ONONDAGA-MADISON-SOUTHERN ONEIDA-CORTLAND-CHENANGO-OTSEGO-

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL NEW YORK.

DAY ONE...TONIGHT.

LAKE EFFECT SNOW WILL CONTINUE THROUGH THE EVENING AND OVER NIGHT HOURS. LIGHT ACCUMULATIONS ARE EXPECTED THROUGH TOMORROW MORNING.

DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

LAKE EFFECT SNOW IS FORECAST TO STRENGTHEN EARLY TOMORROW, AND CONTINUE INTO EARLY MORNING HOURS MONDAY. EARLY INDICATIONS POINT TOWARD SEVERAL INCHES OF SNOW BEING POSSIBLE OVER THIS PERIOD. THE BEST CHANCE FOR SIGNIFICANT SNOW WILL BE FROM NORTHERN ONONDAGA COUNTY, THROUGH MADISON AND WESTERN ONEIDA COUNTY. TRAVELERS IN THIS AREA SHOULD MONITOR LATER STATEMENTS AND FORECASTS FROM THE NATIONAL WEATHER SERVICE. CURRENTLY, EXPECTING UP TO AROUND 3 INCHES OF SNOW FROM 7AM SUNDAY THROUGH 7 PM SUNDAY.

[WNYLakeEffect]

BUFKIT for the 18z NAM has 1.69" of precip for KERI with 18:1 ratios and 30" total. It has 1.29" for KJHW. Easily 24" with good ratios.

BUF seems pretty pessimistic, though. CLE is unusually optimistic and CTP is off in the corner picking their noses.

[CNYWxGuy]

Cayuga Lake has come alive this Evening. Accumulation is around 2" now this Evening, and would be more if the band would hold steady in direction and intensity.

BGM at 910...

NEAR TERM /UNTIL 6 AM THIS MORNING/...

SCATTERED LAKE EFFECT SNOW SHOWERS AND WIDESPREAD FLURRIES WILL CONTINUE INTO SUNDAY. SOME ENHANCEMENT IS BEING SEEN ON THE RADAR SE OF THE FINGER LAKES ESPECIALLY CAYUGA LAKE. HAVE ADJUSTED THE POPS...QPF...AND SNOWFALL UP IN THIS AREA. AMOUNTS SHOULD STAY JUST BELOW THE 4 INCH ADVISORY CRITERIA. SOME INCREASE IN THE INTENSITY SHOULD OCCUR IN THE NEXT 2 TO 4 HOURS AS A SHORT WAVE MOVES THROUGH.

[WNYLakeEffect]

2.5" overnight (BUF had a 50% chance of SNSH and 1/2" of snow). Steady SN now, with moderate flake size and increasing blowing and drifting.

00Z and 06Z NAM were both big here, especially the 06Z. That one brings the 2.0" line VERY close, with me comfortably in the 1.5" line. It would really be something if I exceeded 20". That would make it 5 out the last 6 winters with a 20" storm.

[LakeEffectKing]

2.5" overnight (BUF had a 50% chance of SNSH and 1/2" of snow). Steady SN now, with moderate flake size and increasing blowing and drifting.

00Z and 06Z NAM were both big here, especially the 06Z. That one brings the 2.0" line VERY close, with me comfortably in the 1.5" line. It would really be something if I exceeded 20". That would make it 5 out the last 6 winters with a 20" storm.

The really important question, though, is that if you get 40", do you count it as 2 20" storms???

[LakeEffectKing]

Nice enhancement/convergence coming off Oneida lake, near South Bay on the SE portion of the lake:

[WNYLakeEffect]

The really important question, though, is that if you get 40", do you count it as 2 20" storms???

Geez...I don't know. I've never had to think about that before.

[LakeEffectKing]

S+ here in Liverpool, currently. Haven't taken an official measurement yet (still in my nighttime attire!) by we look to have about 4.5-5" of new snow since last evening....nice dendrite size!!!

(Time sensitive): I'm about where the "e" is in Baldwinsville:

[Master of Disaster]

State College mentioning a possible band forming from Erie to Lancaster Co PA today. That would be one of the longest Lake effect bands that I have personally ever witnessed if it happens.

[WNYLakeEffect]

So close. 12z NAM looks like it upped the amounts and it wants to redevelop a Huron Connection over Chautauqua County on late Wednesday to finish the storm off. Such a tight gradient that I might be able to go from 12-15" in Frewsburg, to 20-22" in the city, 24-26" here, to 30+ at my grandma's house, to 40+ in Panama or Sherman.

SN to -SN continues. Next measurement will be at 2.

[LakeEffectKing]

Fresh guidance: Next 36hrs. + are going to be fun:

[Tornado Girl]

Fresh guidance: Next 36hrs. + are going to be fun:

LEK Right right about that ... your neck of the woods will do well...I wish I could say the same About the up here on the Tug. The LES the other day was not kind to us at all. But at least BUF and points south did well.

[kulaginman]

Fresh guidance: Next 36hrs. + are going to be fun:

Still insisting that a Georgian Bay streamer will impact parts of the Niagara Frontier tomorrow, spitting out a 0.89" maximum over nrotheastern Erie County. If that verifies, it should help ease the pain of the screwjob that area endured last week. I'm wondering if the NWS will make a last-minute upgrade to an LES warning for Niagara and northern Erie Counties tomorrow morning.

[ayuud]

Still insisting that a Georgian Bay streamer will impact parts of the Niagara Frontier tomorrow, spitting out a 0.89" maximum over nrotheastern Erie County. If that verifies, it should help ease the pain of the screwjob that area endured last week. I'm wondering if the NWS will make a last-minute upgrade to an LES warning for Niagara and northern Erie Counties tomorrow morning.

Nice we got about an inch last night.

[Logan11]

Nice to see more of a WNW flow for once. Models almost never even show any real qpf making it east of about Otsego County, but it does get here sometimes...as in an inch or two. I'd certainly take it. My all time record for a purely LES event since 2004 is 4.5 inches.

Very light snow/flurries have persisted all day long here today and I guess it is the northern extent of the stuff that is aiming for the Susquehanna Region mainly. Holding at 25F....

LEK Right right about that ... your neck of the woods will do well...I wish I could say the same About the up here on the Tug. The LES the other day was not kind to us at all. But at least BUF and points south did well.

[LakeEffectKing]

What the models appear to depict is the Georgian Bay bands keep regenerating with the aid of synoptic dynamics/moisture/seeding rotatating in from the east/northeast over the Bay, This translates downstream to L. Ontario, and we see a constant transitory band factory, starting over the ESE counties (extreme SW Oswego/ N. Onondaga then moving WSW'ward to N. Cayuga/ W. Onondaga/Wayne Cos. then to points even further westward replacing the smaller ones that will generate over the Niagara frontier. Meanwhile new "connections/bands" will form over Oswego/Onondaga Cos. and repeat the above movement....with breaks inbetween and some varying intensities, until finally, the last impulse approaches (on Tuesday) to back the winds to a more permanent (for the remainder of the event, for the most part) position in N. Onondaga Co./S. Oswego Co.

L. Erie is pretty straightforward.....A historic dump is forethcoming somewhere between points bounding a point 15 miles north or south of the PA/NY boarder....30-45" I'd presume somewhere in the higher elevations with an almost constant L. Huron connection over the next 4 days or so....

[LakeEffectKing]

LEK Right right about that ... your neck of the woods will do well...I wish I could say the same About the up here on the Tug. The LES the other day was not kind to us at all. But at least BUF and points south did well.

TG, Orographically you guys should be able to produce ample bouts of light to moderate snow (with the aid of occasional synoptic moisture/precip) for most of the next few days.

BTW, the WRF BUF mesos have been very consistant with a very intense band forming this afternoon targeting N/C Onondaga Co. and points back to the lake for a 6-9 hour period (but should be fairly transient). I think the assemblence of what the models are indicating is just starting to develop just south of the city of Oswego and points NW and SE of there.

[LakeEffectKing]

Still insisting that a Georgian Bay streamer will impact parts of the Niagara Frontier tomorrow, spitting out a 0.89" maximum over nrotheastern Erie County. If that verifies, it should help ease the pain of the screwjob that area endured last week. I'm wondering if the NWS will make a last-minute upgrade to an LES warning for Niagara and northern Erie Counties tomorrow morning.

I think the NWS (both BUF and BGM) with upgrade many areas in their respective zones. The dendritic growth has been very good. I have 5.5 inches total (4.5 on the ground) since last night.

[Andyace]

I got a pepper sandwich here so far....