Widespread Lake Effect/Upslope Snows Expected Later this Week...
Posted Tuesday, 18 December 2012
A closed upper level low will continue to slowly move through southern Canada and upstate New York during the later half of the upcoming week. A deep trough and subsequent northwest flow will allow for the first prolonged lake effect snow event of the year. Widespread upslope snows are also expected across the Appalachians up through the White/Green Mountains. Accumulations will be widespread in the snow belt regions, but generally light to moderate amounts.
Lake Effect Snow Outbreak December 21-23, 2012
A significant winter storm will be tracking through the Midwest and Great Lakes by the middle of this week. This 992mb surface low will track across the Great Lakes and begin to weaken across western New York. A closed upper level low will begin to slowly meander across southern Canada increasing moisture under a northwest flow behind the steep cold front. H85 thermals will fall to a meager -6C, but given that lake temperatures are near 10F above normal, there will be enough of a gradient to spark a widespread lake effect event. The flow for the duration of the event will be around 300-315 degrees with possibly an even more northerly component depending on the track of the ULL. Limited instability will prevent significant banding, but nevertheless with PWATs +0.5SD there will be widespread snow shower activity for several days across the region.
This flow will increase snows across favored upslope and orographic locations from northern West Virginia up through the Laurel Highlands. Favored peaks in Garret County, MD up through Mt. Davis, PA and Laurel Summit, PA may see upwards of 10" of snow during this period. Current model QPF is already at an impressive ~0.5 inches. Across the Chautauqua Ridge in southwestern New York, upslope totals may also approach 10" of snow. This will help lay a fresh snow pack to several ski resorts in the region that are featuring a seasonal snow deficit of nearly two feet to date. As drier air begins to rotate into the region on Saturday, widespread light snow shower activity (with a few enhanced SN bands) will begin to focus into a more cellular nature under diurnal forcing. Mesoscale guidance indicates the development of several stronger bands off of Ontario down through possibly Rochester and Syracuse. UUV and omega growth peak during this period allowing for excellent dendritic growth. Snow ratios during this period may approach 17:1 with snow rates at 1in/hr in some locations. Northern Cayuga County through Onondaga and Madison Counties in New York will see the highest accumulations. During this period upslope snows will increase across northern Vermont in the higher elevations. This will be a multi-day event for this area with amounts approaching two feet above 3000ft by Monday.
Given the length of the fetch and typical northwest flow, a few snow bands may stretch east of the mountains into the central ridge and valley region of Pennsylvania and Poconos. Any accumulations in this area will be isolated and generally around 1-3 inches. A bit of Huron connection may be possible Saturday night during the peak of the lake effect snow event. At this point in the medium range, it is too early to highlight typical bands such as the 322 streamer.
Drier and more stable air will cutoff the cyclonic circulation by early next week with more seasonable temperatures. Winds will also begin to relax.
Regional Radar...
(Courtesy of NOAA)
Regional Advisories...
(Courtesy of NOAA)
Storm Reports...
None.
Storm Impacts...
1. Sustained winds of 20-30mph with gusts approaching 40mph are expected over the region with whiteout conditions possible in snow squalls.
2. Deep moisture field and long fetch will allow snow showers to stretch east of the mountains.
3. Heavy snow accumulations in favored 300 degree snow belts are expected with totals approaching up to 10"
4. First widespread lake effect event of the winter will have greater impacts than normal due to the the infrequency this December.
5. Temperatures and air mass will be marginally cold and generally in the upper 20s to mid 30s for most areas.
Snow Map...
*The heaviest snow accumulations will be confined to the higher elevations and favored northwest flow snow belt regions. The highest accumulations are expected near the Syracuse metro region and across the upslope effect region of the Green Mountains near Stowe in northern Vermont. Heavy accumulations are also likely up through West Virginia and into the Laurel Highlands. Outside the snow belts snow amounts will be more isolated and dependent on the exact location of the bands and showers which are impossible to forecast exactly at this point in time.
Current Great Lakes Water Temperatures...
(Courtesy of NOAA)
Current Lake Erie Wind Direction and Speed...
(Courtesy of NOAA)
Current Lake Erie Water Temperature...
(Courtesy of NOAA)
"Selected City Accumulations"
Erie- 4-6" of snow with higher amounts to the south and east of the city
Meadville, PA- 4-8" of snow
Bradford, PA- 3-6" of snow with higher amounts near Warren County
Butler, PA- 2-4" of snow
Pittsburgh, PA- 1-4" of snow with isolated higher amounts
Latrobe, PA- 1-4" of snow
Indiana, PA- 2-4" of snow
Johnstown, PA- 5-10" of snow with higher amounts possible
Somerset, PA- 4-8" of snow with higher amounts possible
Altoona, PA- 1-4" of snow
Du Bois/Clearfield, PA- 3-6" of snow with locally higher amounts
Philipsburg, PA- 3-5" of snow
State College, PA- 1-3" of snow
Lock Haven, PA- 1-3" of snow
Williamsport, PA- Locally 1-2" of snow
Mt. Pocono, PA- 1-2" of snow
Selinsgrove, PA- Locally 1-2" of snow
Harrisburg, PA- Isolated C-1" of snow
Hagerstown, MD- Isolated C-1" of snow
Cumberland, MD- 1-3" of snow
Frostburg, MD- 2-4" of snow
McHenry, MD- 4-8" of snow
Oakland, MD- 4-9" of snow
Snowshoe, WV- 4-9" of snow
Buffalo, NY- 2-5" of snow with higher amounts to the south and west
Watertown, NY- 3-5" of snow
Syracuse, NY- 6-12" of snow with locally higher amounts
Albany, NY- Locally 1-2" of snow
Ithaca, NY- 1-4" of snow
Binghamton, NY- 1-2" of snow
Saranac Lake, NY- 3-5" of snow
Utica, NY- 5-10" of snow
Burlington, VT- 1-2" of snow. Higher amounts to east approaching 12"
North Conway, NH- 1-4" of snow
"Subject to Change"
Current Northeast Snow Depth and Northeast Wind chills...
(Courtesy of Wunderground)
Model Analysis
The GFS is a low resolution global model that typically does not do well in mesoscale events such as lake effect snow. But forecast QPF maps already suggest widespread high amounts over the Northeast snow belts, which is very impressive at this forecast range. A deep moisture field and long northwest fetch is suggested. The ECMWF is also in full support of this event especially across the upslope regions of northern Vermont where an extended multi-day period of heavy snow is possible. Isolated amounts in this region could reach 24" in some areas above 3000ft. All guidance supports a closed low that will allow for a bit of synoptic influence favoring some lighter snows outside the typical snow belts especially for western Pennsylvania and upstate western New York. These amounts will remain light though with QPF less than .15" for most areas. At this range, the NAM and other high resolution guidance is a bit too far out for their time frame. Latest trends in the GFS/ECMWF are showing a possible increase northerly component which would decrease the widespread activity of the snow showers. At this time it looks like the Buffalo metro area will be spared the worst of the event, while areas towards Rochester and Syracuse will be more favored.
After the Storm
As temperature anomalies approach +6F for the month of December for many climatological reporting stations across the Northeast, many are left asking where is winter. A majority of the cold air is locked well to the northwest of the contiguous United States in northern Canada. Even across areas seeing the next bout of winter weather in the Midwest, H85 thermals never even fall below -10C south of the Canadian border. This is a clear indication that much of the nation is well above normal in the temperature department. A +EPO in correspondance with a -PNA will continue to keep the cold air locked up to the north through the end of the month. A few energy meteorologists have been hinting at winter storm chances post Christmas in the Northeast, but given the latest tropical monsoon forcing indices out of the Indian Ocean and the status quo of the current NAO, it is likely these middle latitude cyclones will continue tracking through the Great Lakes. If any secondary cyclogenesis occurs on the east coast, it will only favor far northern New England with wintry precipitation. Unless we see a dramatic change in ensemble guidance and teleconnections, period through the end of December will be snowless across much of the east. While temperatures will likely average near normal, they will feature an oscillating pattern of unseasonable warmth as lows track to the northwest, and then brief arctic air behind the cold fronts.
After a near record dry November, the polar jet has begun to increase in activity as we continue a stormy pattern with several shortwaves per week. This pattern will continue through early January with precipitation totals averaging above normal for all climatological stations. While the MJO forcing remains meager and few changes in the NAO are expected, there are a few signs that the EPO will shift negative and begin to dump some arctic air farther south. As we also enter the coldest portion of the year, it is likely snow chances will begin to increase by early January. That being said, there are no signs of any abnormally snow periods.
Despite another snowless and record warm start to the meteorological winter, the synoptic pattern is very different than last winter. Whether that is encouraging or not, it is critical for snowlovers that we do not see any development of a PV in Alaska. This would disrupt the potentially favorable Pacific by January and allow increasing upper level heights over the eastern United States. The main idea to take from the long term will be a continued stormy pattern of Great Lakes cutters, while the east coast sees mostly rain in association with frontal passages. Any front end warm air advection winter precipitation will likely be confined to northern New England. If any pattern change does occur, it will likely be post New Years.
Please post storm reports in this blog from across the Northeast during the winter storm and please post location of observation in each report...
This blog is in progress. Check back soon...
Winter Forecast 2012-2013... Link
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Lower Susquehanna Valley Doppler...
(Courtesy of WGAL)
"10mi northeast of Harrisburg 2012-2013 Winter Statistics"
(Snow Stats)
Monthly Total (October)- 0.0in
Monthly Total (November)- 0.8"
Monthly Total (December)- 9.5"
Seasonal Total- 10.3"
Winter Weather Advisories- 4
Winter Storm Warnings- 0
Ice Storm Warnings- 0
Blizzard Warnings- 0
Freezing Rain Advisories- 0
Winter Storm Watches- 0
(Temperature Stats)
Lowest High Temperature- 36.1F
Lowest Low Temperature- 18.5F
Wind Chill Advisories- 0
Wind Chill Warnings- 0
(Snow Storms Stats)
First Trace of Snow - November 24 - Lake Effect Snow Showers
First Measurable Snow - November 27 - 0.8" - Overrunning event
Enhanced Clipper - December 24 - 2.1" - Christmas Eve Snow!
Miller B - December 26 - 3.3" - 0.15" of freezing rain also
Miller B - December 29 - 4.1" - Moderate all snow event
Reader Comments
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11:00pm, 28.3F, light sleet, 3.2" storm total snow/sleet.
Dry slotting from 3:40pm to 5:30pm held accumulations down. Snow began to turn to sleet at 5:30pm. No freezing rain as far as I can tell.
Still no snow from this storm. We're in a dry slot that the local forecaster promises will fill in. Apparently we're to expect the heaviest snow between 6am and 1pm. I guess we'll see what that means for going to work, as I work 3-8pm. The only thing that would cancel me going to work would be a power failure.
Hoping for a Snow Day all the same. ;-)
{{{ {{ { Thanks LT! } }} }}}
kaaterskillfalls ~ I'm looking forward to your updates!
Driving from Westchester early yesterday the temp was 24 in the north of the county. Was 32 on the Saw Mill and held that all the way down the GSP until the Driscoll. Was 37 on the other side of the driscoll.
And thats right where the line set up early on. The I95 storms continue.
Traffic cams were unbelieveable as the evening wore on.
The GFS has been on top of everything since we changed patterns after the snow that followed Sandy.
It saw this storm two weeks ago and held it in it's models consistently.
ECMWF had been consistently weaker, south, and colder. NAM has been consistently weaker, north, and warmer. GFS had this period down with both the lulls and the storms.
Now we wait until it misses the next pattern change and creates a ghost storm or misses one altogether.
Until then watch our forecasting heavily favor the GFS....as well it should have been in the first place given how well it's locked this particular pattern down.
Saturday looks increasingly interesting for many more people to get a snow storm. Let's see how the models feel about that come later today or tomorrow morning once this storm has finished departing.
...DAY 3...SATURDAY AND SATURDAY NIGHT
...MID-ATLANTIC AND NORTHEAST COAST...
A LOT OF SPREAD TO CONSIDER WITH THE POTENTIAL FOR ANOTHER SNOW
STORM TO IMPACT THE NORTHEAST COAST SATURDAY NIGHT. THE NAM WAS
RULED OUT DUE TO POOR CLUSTERING WITH OTHER GUIDANCE WITH SURFACE
LOW TRACKING NORTHEASTWARD FROM THE SOUTH CAROLINA COAST...WHILE
THE 00Z GFS/12Z ECMWF/00Z UKMET AND THE GLOBAL ENSEMBLE MEANS
CLUSTERED FAIRLY WELL. HOWEVER...THE ENSEMBLE MEMBER SPREAD IS
ABOUT 4 TO 5 TIMES AS LARGE IN DIAMETER AS THE DETERMINISTIC
CLUSTER...THUS SUPPORTING LOW CONFIDENCE AS A WHOLE. THE 00Z
ECMWF IS EVEN CLOSER TO THE COAST WITH ITS LOW TRACK THAN ITS
PRIOR RUN...SUGGESTING THE POSSIBILITY FOR EVEN HIGHER SNOW
AMOUNTS. HOWEVER...THIS IS JUST 1 ONE OF MANY SOLUTIONS TO
CONSIDER. GIVEN THE COMPLEXITY OF THE MULTIPLE STREAMS COMPRISING
THE SHORTWAVE PATTERN...HAVE CHOSEN INTERMEDIATE SOLUTIONS TO
DERIVE THE SNOW PRO ABILITIES WHILE ADDING SOME ENHANCEMENT FOR
SLIGHT CHANCES OF 8 AND 12 INCHES OF SNOW OVER PARTS OF THE
NORTHEAST COAST...WHERE THE GEFS AND ECMWF ENSEMBLE MEANS ARE MOST
SUPPORTIVE.
SATURDAY...
THIS IS WHERE THE DRAMA BUILDS AS THE NEW 00Z ECMWF GOES BONKERS
WITH EXPLOSIVE CYCLOGENESIS SOUTH OF NEW ENGLAND. AT 06Z SUN THE
ECMWF AS A 972 LOW OVER THE 40N/70W BENCHMARK AND FURTHER BOMBING
TO ABOUT 959 MB JUST SOUTH OF NOVA SCOTIA 18Z SUN! THIS RAPID
DEEPENING GENERATES QPF OFF THE CHARTS WITH STORM TOTAL OF 2+
/LIQUID/ OVER CAPE COD!
===
Jersey Shore residents were buffeted with winds as high as 74 mph, according to the National Weather Service. The strongest gust of wind was 74 mph recorded in Brick at about 9:30 p.m. Wednesday. Other parts of Ocean County experienced gusts of up to 70 mph, and a 61 mph gust was recorded in Sandy Hook.
That model has been awful since it's dual score of Sandy and the snow storm that followed.
Remember, it had two more superstorms lined up in the pipeline and they were ghost storms.
Does it get back on the wagon here? Who knows...but I wouldn't be too interested in it given it's recent awful showing during this current weather pattern.
Unless this current storm is ushering in a new pattern....and the ECMWF is latching onto that new pattern... I'd be suspicious.
I guess there are some hints we're about to change. Well below normal temps to begin January. Perhaps Saturday's snow storm is the first of the "new pattern".
Let's see how the continuity goes here. Might be time to hop off the GFS as this pattern it handled so well comes to a close.
And thus is the continued problem with the science and the programming of the models.
Yeh,wouldn't go with that model,but the others are beginning to strenthen the next system,so would not be surprised if here in eastern mass we have some plowable snow.As with most of these coastal storms,it really depends where it deepens sooner or out at sea to late to have much effect.
Ok,they've been flip flopping,so what do you base that on. It wouldn't surprise me,but a lot of them we're strengthening this system.
Speaking to the OEM guy who is in our neighborhood and he said numerous wires down and flooded closed streets in the town.
It was a good storm for sure. Followed the strongest model solutions.
Impressive season so far! We've definitely been locked in a zone since abour March 2009 here. A little lull last winter was it and we've been right back at it.
Did a fun 2 hr snowshoe excursion through town last night - took advantage of a storm that seemed to be something from what I remember winter being like (NO RAIN ! NO ICE !).
Anyways, from downtown Dansville, NY in the western Finger Lakes - measured 13" this morning after it probably settled out by a couple inches.
Not snowing anymore - now here comes the cold and wind !
Flip Flopping will be there both in intensity and ptype as the models mishandle the percevied environment for the new storm run to run...as this lingering system continues to create initialization havoc for them.
When reading the Mt Holly discussion this morning their wording sounds very tentative...a lot of if then type reading it seems. This should do this then that will do that. The formative portion of this system going down into the mid-atlantic inland areas phase seems complex.
I think we're stuck until later today or tomorrow morning. Unfortunately that does not give us much time prior to the onset of the next event but if we want detail we're going to have to wait.
Could you say a word about WHERE the Saturday storm looks to be headed? I'm driving to a family gathering from NW VT to the Boston area. Back on Sunday. Good to go?
Yikes! Just saw bwi's comment at 262. Sounds like I'd better watch this one closely!
SATURDAY AND SATURDAY EVENING...DIFFERING PRECIPITATION AMOUNT
SOLUTIONS BUT LITTLE DOUBT THAT IT WILL SNOW OVER MOST OF OUR FORECAST AREA. FOR NOW... SINCE THE TIMING OF THE AMPLIFICATION OF THE TROUGH WILL DICTATES DURATION AND AMOUNTS...WE ARE
FORECASTING A GENERAL 6 TO 12 HOUR EVENT WITH POTENTIAL WATCH AMOUNTS IN SOUTHEAST PA...S NJ.. PORTIONS OF NE MD AND N DE.. 4 INCHES. ADVISORY AMOUNTS OR AT LEAST NECESSARY ROAD TREATMENT AMOUNTS
EXPECTED ELSEWHERE. SNOW GROWTH MAY ALLOW AN INCH/HOUR FOR AN HOUR OR TWO IN A FEW SPOTS OF THE WATCH AREA SATURDAY MORNING. TEMPERATURES SHOULD BE WARM ENOUGH IN NE MD AND DE TO PERMIT A BIT OF MELTING
ON PAVEMENT IN THE AFTERNOON.
Looking to do colder more zonal southerly systems. Then some dry and cold, then clippers appearing late in the 10-day runs.
Are we looking at a January desert followed by a return of coastal systems in February?
...MID-ATLANTIC/OH VLY TO COASTAL NORTHEAST/NEW ENGLAND...
THE MODEL SPREAD CONCERNING THE SRN STREAM SHORT WAVE LIFTING OUT
OF THE LWR MS VLY AND ITS POSSIBLE PHASING ALONG THE MID-ATL
COASTLINE WITH A VIGOROUS NRN STREAM VORT SEEMS TO HAVE NARROWED
SOME WITH THE 12Z OPERATIONAL SUITE. THE 12Z GFS AND ECMWF ARE
VERY AGREEABLE AND HAVE SUPPORT FROM THE EC MEAN ON A SRN STREAM
LOW SLIDING FROM SRN MS TO SRN GA BEFORE THE UPPER DYNAMICS
TRANSFER OFF THE COAST TO MEET THE NRN STREAM AND DEVELOP A NEW
AREA OF LOW PRESSURE OFF THE MID-ATL COASTLINE. THIS SHOULD RESULT
ON TWO AREAS OF HEAVIER QPF ON SAT... ONE ALONG THE GULF/SOUTHEAST
COASTS AND ANOTHER ON THE WEST SIDE OF THE APPALACHIANS OR ALONG
THE MTN SPINE IN THE COLD SECTOR. THIS WOULD ALLOW .25 TO .50 INCH
QPF AMOUNTS IN THIS AREA ALONG WITH 4 AND 8 INCH HVY SNOW PROBS.
NOW IN QUESTION ON SAT IS WHERE THE RAIN/SNOW LINE SETS UP AND
RIGHT NOW IT APPEARS TO SLICE THROUGH THE DC METRO AREA TO SRN
NJ... SO TO THE NORTH AND WEST OF THIS LINE FAVORABLE CONDITIONS
FOR A FEW INCHES OF SNOW WITH THIS QUICK SYSTEM. BY SUN... THE
AREA OF LOW PRESSURE WILL DEEPEN RAPIDLY OFF THE NERN SEABOARD...
AS IT APPEARS THE HIGHEST UVVS/DEFORMATION ZONE WILL REMAIN WELL
OFF THE COAST AND JUST CLIPS RI/ERN MA AND COASTAL MAINE. OVERALL
HPC FAVORED THE 12Z GFS/ECMWF HEAVILY BOTH DAYS FOR THE
INCREASINGLY CONFIDENT HEAVY SNOW PROBS.
Here in NW VT, I have 16" of snow (so far!)...
Sweet! 16" here in Jericho and still falling.
I'll be posting photos as they upload. Here's another:
Mini Mohawk :-)
You're welcome. :-)
In my opinion, 10" of snow is perfect for sports, walks and messing around. I wish I could send the other 6" to folks who are snow starved!
I noticed huge flakes in yesterday's storm. Bigger than I've ever seen. What causes huge snowflakes? I've always wondered why individual snowflakes cluster like that.
Today everything is blanketed in white. Ollie my dog is loving eating it, running in it and unburying toys.
Clusters happen when snowflakes fall through warmer air and get a coating of water on them, making them sticky. Cool, huh?
Thanks, TheF1Man ~
Do you have a particularly good link for keeping watch over this weekend storm?
Not sure if this answers your question, but other than this blog I check the NWS snowfall prediction maps and compare to say TWC predictions (just to see). During the storm I like checking this radar:
http://www.intellicast.com/National/Radar/Current .aspx?animate=true
What kind of link are you looking for?
TheF1Man ~ That's a good link. Thanks!
I just wanted to be able to follow the storm predictions a bit earlier than they tend to get posted.
Decisions need info. :-)
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