Heavy Snow Squalls for Northeast Post Storm...
A double low system will move through the Northeast generally with heavy rain for most areas along with some wintry precipitation for northern New England. Behind the low complex, arctic air will move across the region in correspondence with a very impressive jet streak. This vortex will enhance an area of snow squalls, which will affect many areas with advisory or sub advisory snows. Flash freezes are likely for many areas on Friday along with an increasing lake effect snow cyclonic flow. Winter will be in full force on Friday and Saturday. Winds will also increase to advisory criteria.
Current Surface Plot...
(Courtesy of HPC)
Thoughts on January 11-14 Storm System and Lake Effect Snow...
2-5pm Wednesday: Strong WAA and a southerly jet will continue to allow temperatures to rise over the region in correspondence with the max diurnal heating of the day. 1pm surface observations indicate temperatures above freezing for all locations across Pennsylvania, Maryland, and Delaware. Also temperatures across New England are above freezing given clear skies on the visible satellite. Dew points are beginning to rise across southern areas as the southerly jet increases moisture and milder temperatures. A departing 1024mb anticyclone over New England will allow a CAD situation to unfold for northerly locations across New York State, Vermont, New Hampshire, Massachusetts, and Maine. By 5pm rain will be spreading across Pennsylvania and New Jersey with rates around .1in/hr in some areas. Cirrus will begin to thicken over New England by evening preventing temperatures from falling due to radiational cooling. Therefore temperatures will range from 34-38F across the areas north of the Massachusetts Pike into Vermont and New Hampshire. Dew points will remain in the 20s.
5-10pm Wednesday: Stratiform rain will continue to spread over the entire Northeast edging into southern New England. Rates will range from .1in/hr to .2in/hr especially towards New Jersey. As rain moves into areas north of the MA pike, evaporational cooling will allow for a quick drop in H85 thermals below 0C. But WAA will prevail under a strengthening LLJ. Any snow will not last as guidance indicates a mid level warm layer around 925mb. Snow accumulations will generally be under 1in as far north as southern Vermont and New Hampshire. As the warm tongue positions across southern New England, sleet will increase in some areas from Worcester on northward. Sleet amounts will also remain below 1in. 2m temperatures will fall from the mid to upper 30s into the lower 30s. Rain will fall heavy by 10pm over parts of Maryland and Washington DC with QPF totals up to .75in up to this point.
10pm-12am Wednesday- As WAA continues to increase thermal heights over southern New England, any sleet will change to freezing rain. This will be prevalent across parts of the Adirondacks through the Green and White Mountains. Freezing rain will also occur across the Berkshires and as far south as the hills near Worcester. But 2m temperatures will rise from the low 30s into the upper 30s slowly. Any freezing rain amounts will be less than .1in. Rain will begin to end across southern areas by early morning Thursday with QPF totals around 1in near Washington DC.
12am-4am Thursday: The double barrel low will begin to move up through Pennsylvania and New York state with H85s increasing to near +5C over southern Pennsylvania. Rain will be ending as far north as the Mason-Dixon line. An increasing southerly flow will allow temperatures to rise into the mid 40s into the I-95 corridor from Connecticut on southward. The anticyclone to the northeast will begin to weaken and depart allowing the confluence flow to wane. Heavy snow will begin to fall across northern Vermont and northern New Hampshire will amounts around 4-6in. 925mb temperatures will rise to near +1C to the Canadian border changing any snow to sleet and freezing rain. The surface lows will be rapidly advancing into Canada quickly shutting off precipitation as far north as the tristate region.
4am-8am Thursday: This period will feature any wintry precipitation changing to light rain and drizzle over southern New England. Total QPF in this region will be around 1-1.25 inches. Heavy snow will be falling across northern Maine. Amounts will exceed warning criteria in this small area. Meanwhile an arctic front will begin to move into the eastern Great Lakes. Clouds and warmer air across the entire Northeast will only provide areas of drizzle and low level fog. Temperatures will rise into the lower 50s across the I-95 corridor. Any ice or snow that accumulated along and south of the MA pike will quickly melt even across Pennsylvania and New York State in the higher elevations.
8am-2pm Thursday: The arctic front and associated ULL over Ohio will quickly advance towards western Pennsylvania at the end of this period. A bit of sunshine may occur in the dirty warm sector especially for southern and eastern areas. H85s will drop below 0C once again into western New York and western Pennsylvania. Generally cloudy with occasional drizzle and mild temperatures will be ongoing across the entire Northeast. Any snow or sleet over northern Maine will begin to come to an end.
2pm-8pm Thursday: A 992mb low over Michigan will slowly advance east associated with a strong pool of cold air associated with a series of vortices spinning into Pennsylvania. The arctic front will slowly progress over western Pennsylvania, western New York State, and western Maryland. An increasing pressure gradient will allow winds to increase behind the front along with a developing area of QPF as lapse rates increase in correspondence with a vigorous piece of energy. The atmospheric column will begin to cool over western areas rapidly changing rain to heavy snow with strong winds.
8pm-12am Thursday: A blossoming area of QPF over western and central Pennsylvania will be associated with a high-impact snow event. Total QPF will be around .25-.6in. This will be associated with a period of heavy snow from western Maryland north into western New York State. 1000-500mb thicknesses will drop sub 530dm with rapidly increasing snow rates. The strong northwest flow will along wind sustained to increase near 20-30mph with gusts up to 55mph. This will be wind advisory criteria. Temperatures will rapidly fall sub 30F. Snow ratios will increase to 20:1 in addition with increased orographic lift combined with lake enhancement. This will be a 2-4hr period of heavy snow with amounts around 3-6in along and west of the Alleghany Front.
12am-6am Friday: This band of QPF will shift northeastward as a 988mb surface low moves into central New York State. As the post frontal precipitation moves eastward, it will extend ahead of the 0C H85 line. This will allow precipitation to initially be rain, but rapidly change to snow. Flash freezes are likely all the way to the coast. High temperatures will be reached in the morning hours and fall into the 20s throughout the day for all areas. The best dynamics will shift into New York State and western New England. Squalls will begin to weaken as they head east of the Alleghany Front. Snow accumulations will begin to focus across central New York. Spotty 1-2in amounts are likely from Washington DC to White Plains, NY but generally most areas will be at a coating or less. Snow accumulations of 3-7in are possible into western New England especially along and west of the favored upslope regions in the Berkshires and on northward. Advisories will likely be issued for a widespread area given flash freeze, falling temperatures, high winds, and temporary heavy snow. Short periods of blizzard conditions are possible into north central Pennsylvania and central New York State.
6am-12pm Friday: The arctic front will push towards I-95 and the Atlantic coast with brief rain changing to snow showers as the column cools. Little to no accumulation is likely. Winds will be easily advisory criteria across the entire Northeast viewing area. Temperatures will continue to fall and the deformation axis of snow will be waning and moving through northern New England. A west-northwest flow will prevail as temperatures drop below H85s drop below -10C. The lake effect snow machine will begin to kick in across the typical snow belts associated with a 300 degree flow. The initial flow will be westerly with bands setting up near Buffalo and Watertown. The Ontario band will shift south into Oswego county, New York.
12pm-8pm: The lake effect snow machine will rapidly increase in this time period as the flow shifts to the northwest. Bands will be organized in a multi-band setup with only moderate accumulation. This flow will aid the upslope favored regions from western Maryland through the Laurel Highlands in Pennsylvania. Heavy upslope snows will begin across the Berkshires into the Greens.
8pm-Saturday morning: The northwest flow will begin to relax as the pressure gradient weakens and winds begin to drop below advisory criteria. Upslope snows will be ongoing in this period with total accumulations of 12in+ for northern Vermont particularly towards Mt. Mansfield and Stowe. Amounts of 6-12in will be more likely across the upslope regions in the White Mountains and Berkshires. 6-12in amounts are also likely over western Maryland into the Laurel Highlands through the snow belt regions of northern Pennsylvania. New York State accumulations will generally be a widespread 1-4in with localized 6-12in amounts for the favored banding locations across the eastern finger lakes towards Cortland county.
By Saturday afternoon, high pressure and increasing heights will begin to end the lake effect snow machine.
Regional Radar...
(Courtesy of NOAA)
Regional Advisories...
(Courtesy of NOAA)
Storm Reports...
None.
Storm Impacts...
1. Heavy stratiform rain with total amounts ranging from 1-1.5in. Recent dryness will likely prevent any flooding.
2. Freezing rain and sleet is likely for parts of northern New England affecting travel through Thursday late morning.
3. Heavy snow squalls likely across the entire Northeast Thursday night into Friday with light accumulations.
4. Winds will increase to 20-30mph sustained with gusts to 55mph; advisory criteria.
5. Flash freezes likely all the way to the coast with rapidly falling temperatures Friday. Widespread travel impacts.
Snow Maps...
***The final snow map for the entire Northeast includes total accumulations for the entire event including the synoptic storm, ULL, and lake effect. This does not indicate total snow depth as snow may melt before the arctic air floods into the region. The Pennsylvania snow map includes both lake effect and snows from the upper level low.
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 for the Northeast...
Hagerstown, MD- Rain then a coating to 1in of snow with snow squalls.
Baltimore, MD- Rain followed by snow squalls; coating to 1in.
Salisbury, MD- Rain followed by scattered snow showers; no accumulation.
Pittsburgh, PA- Rain then a period of heavy snow then snow showers; accumulations 2-5in
State College PA- Rain followed by heavy snow squalls; accumulations 1-4in
Williamsport, PA- Rain then heavy snow squalls; accumulations 1-2in
Altoona, PA- Rain then a period of moderate snow showers followed by snow showers; accumulations 2-4in
Harrisburg, PA- Rain then scattered snow squalls; c-2in of snow possible
Lancaster, PA- Rain followed by scatted snow squalls; c-1in of snow possible
Philadelphia, PA- Rain then scatted snow showers; no accumulation
Allentown, PA- Rain then scatted snow showers; a coating of snow possible
Scranton, PA- Rain then scatted snow squalls; 1-2in of snow possible
Washington, DC- Rain then scattered snow showers; a coating of snow possible
Wilmington, DE- Rain then scattered snow showers; little to no accumulation
Dover, DE- Rain then scattered snow showers; no snow accumulation
Trenton, NJ- Rain followed by scattered snow showers; a coating of snow possible
New York City, NY- Rain then scattered snow showers; no snow accumulation likely
Poughkeepsie, NY- Rain then scattered snow squalls; 1-2in of snow possible
Binghamton, NY- Rain then a period of moderate snow; 1-4in of snow possible
Ithaca, NY- Rain then a period of heavy snow followed by scattered snow showers; 3-7in of snow possible
Albany, NY- Rain then scattered snow squalls; 1-2in of snow possible
Hartford, CT- Rain then scattered snow squalls; c-2in of snow possible
Concord, NH- Light snow 1in accumulations, freezing rain .1in accumulation then rain followed by snow 1-4in
Providence, RI- Rain then scattered snow showers; little to no accumulation
Worcester, MA- Freezing rain .1in accumulation then rain followed by snow squalls 1-3in possible
Boston, MA- Rain followed by scattered snow showers; little to no accumulation
Nantucket, MA- Heavy rain and gale force winds
Hyannis, MA- Heavy rain and gale force winds
Burlington, VT- Wintry mix followed by rain and then heavy snow squalls; 3-6in of snow accumulation
Portland, ME- Wintry mix then rain followed by scattered snow squalls; 1-2in possible
Bangor, ME- Wintry mix followed by heavy snow squalls; 3-6in possible
"Subject to Change"
Current Northeast Snow Depth and Northeast Wind chills...
(Courtesy of Wunderground)
Model Analysis
The only model inconsistencies remain for the upper level low forecast position and the intensity of the vortex responsible for snow squall activity with the arctic frontal passage. The exact position and track will be critical to the snowfall max accumulations track. GFS tends to maintain the best dynamics across northern Pennsylvania and western New York State while the NAM and other guidance suggest a more sustained band of rain/snow moving across the entire northeast. Current boundary layer progs by high resolution guidance indicate temperatures above freezing for the majority of the QPF suggesting limited snow accumulations east of the Alleghany Front. Skewt charts also indicate the strongest winds will remain around 925-950mb and will likely only mix to the surface during an energy momentum transfer during the frontal passage. ECMWF guidance is even weaker with the ULL with minimal snow accumulations for all areas generally below advisory criteria. Lake effect snow shower activity will increase by Friday. NAM simulated radar shows several longer bands stretching east of the mountains in New York State and Pennsylvania, but exact location remains uncertain until we get closer to the event. Total SREF QPF for lake effect snows are generally .4in or less. This is due to the unorganized activity with a multi band setup.
After the Storm
As to be expected given this winter's track record, guidance and global teleconnections are no longer supporting a sustained pattern change. Recent ECMWF weeklies and NAEFS prognostics indicate a brief cold period this weekend followed by increasing anomalies towards weeks 2 and 3. It still appears earlier indications of a gradient pattern are likely, but the recent retreat in the expected -NAO appears to have lifted the thermal gradient farther north. This will allow for a more amplified southeast ridge with warmer temperatures reaching farther north locations. Current teleconnections look terrible for a sustained pattern change with a +NAO, -PNA, and questionable MJO phase change. While the pattern will become more stormy, long range guidance suggests very mild weather in the 2-3 week period. ECMWF weeklies were near +5F for the northern Middle Atlantic. Any colder weather will remain across Canada and towards Alaska. There will likely be some sort of snow accumulation before the end of the month for all locations, but east coast cyclogenesis remains unlikely. Towards February a few wavelengths show a return to brief colder weather early in the month, but given the state of the increasing solar activity and madden jullian monsoonal patterns, this remains questionable. Wavelengths suggest stormy periods towards the 16th and 21st of January, but rain vs snow will be a problem through the entire Northeast.
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 2011-2012... Link
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Lower Susquehanna Valley Doppler...
(Courtesy of WGAL)
"10mi northeast of Harrisburg 2011-2012 winter statistics"
(Snow Stats)
Current Snow Cover- 0.0in
Monthly Total (October)- 5.5in
Monthly Total (November)- 0.0in
Monthly Total (December)- 0.4in
Monthly Total- (January)- 0.2in
Seasonal Total- 6.1in
Winter Weather Advisories- 1
Winter Storm Warnings- 1
Ice Storm Warnings- 0
Blizzard Warnings- 0
Freezing Rain Advisories- 0
Winter Storm Watches- 1
(Temperature Stats)
Lowest High Temperature- 29F
Lowest Low Temperature- 10F
Wind Chill Advisories- 0
Wind Chill Warnings- 0
(Snow Storms Stats)
Historic October Nor'easter - October 29 - 5.5in of wet snow
322 Lake Effect Snow Band - December 17 - 0.3in of wet snow
Weak Clipper - December 29 - 0.1in of snow
322 Lake Effect Snow Band - January 18 - 0.2in of snow
Reader Comments
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Thanks for your report! The entire column is beginning to warm completely above freezing. Any additional precipitation in the capital district will likely be rain. Temperatures will warm into the mid 40s. A sharp cold front and associated precipitation will cause a burst of rain changing to snow probably early Friday morning. Snow showers are possible throughout Friday.
Check out the Taunton NWS radar near Worcester; the higher returns is the exact position of the snow/mix line. Very cool!
I also saw those massive snowflakes in the Albany area that SnoDay refers to in the post upthread - they were more like snow bombs ! And while they were falling it was also raining hard and sleeting and ice pellets... hahaha
Weekends I moonlight as a ski instructor in the Catskills - what do you think of the prospects for the mountains picking up more snow over the next few days Blizz ? - big holiday ski weekend coming up so I hope we have some fresh stuff. Will the lake effect be strong enough to blow into the western Catskills ?
Fetch won't be that great for lake effect bands, but I cannot rule out a rogue streamer. Increasing shear should end lake effect by Saturdat afternoon at the latest. ULL may add some light accumulations in the Catskills, although central New York State looks ideal. None the less another 1-4in is probably likely for the mountains.
Now to keep the rain at bay...
Looking at that, I see a familiar pattern - from the SW edge of Lake George down to just about Saratoga there seems to be a pretty significant drop in snow totals. This seems to happen a lot but I never could pin down exactly what types of storms cause this, or whether it might just be the river valley and ADK foothills causing it. Any thoughts?
It appears we got the tiniest dusting of snow, then rain then sleet and ice (there's a crust out there), then it switched back to snow for about 15 minutes, really coming down for about 2 minutes, and now it's snowing but lighter and ... different. I think it must be switching over to something else again.
Good day to stay home and nestle in. However, I work at the Library 3-8pm.
Take care, all. This storm has a very strange personality!
That's helpful. Thanks, Crowe!
Good to see what's going on, and so happy for those who got 6" or so. But what a strange beast.
Beautiful blue skies and 50F here now.
Modified comment: NWS just put snow showers back in the forecast for DC after all:
Tonight: A chance of rain before 1am, then rain and snow likely between 1am and 4am, then a slight chance of snow after 4am. Cloudy, with a low around 36. South wind between 7 and 16 mph. Chance of precipitation is 70%. New snow accumulation of less than a half inch possible.
Meanwhile, as for Vermont, here's an update from VT's Mark Sutkoski
My guess is it's mostly terrain influenced but I'm sure there are other factors as well.
Like Crowe said, it's usually a drop in elevation / rise in temperatures there as compared to areas north/northwest.
Still socked in the low stratus here, but starting to look a bit brighter well to the south. Mid 40s here, but 50F not to far away.
Probably some whiteouts on the interstates in and out of Pittsburgh tomorrow; probably going to be a mess of a morning and maybe evening commute. Some lake effect snow showers likely all day there.
Blizz - there is water in some fields from this past fall. I guess no place for it to go. It's not seeping into the ground. I measured 0.77" of rain for the storm.
What did you think of that place? As close as I am to it and I drive by it at least once a day, I have never been there to eat.
How is Maine with this last storm? Earlier this week they were brutally cold. My in-laws in Niles, MI have a WSWarning up for 8-14". Their forecast doesn't have them above freezing until Monday. It looks like they will have some cold conditions this weekend. I guess the same for Green Bay on Sunday.
It is a nice little lunch cafe. I ordered a grilled catfish sandwich which was excellent, and they have wonderful homemade chips. It is definitely a nice spot for an inexpensive meal.
Maine is picking up quite a bit of snow with nearly 10in in many spots. Temperatures will also drop below 0F a few nights likely.
Here in Cape Elizabeth we were forcasted to get 2-4 but as of now in my yard we have 11. Some how I still went to school in this, dispite all the communites around us being out. :/
Why are areas of lower Michigan getting temps in the single digits, but we aren't getting that cold? I realize the air is moving over land and warms, but usually that air gets to us also, maybe not quite as cold.
Cape Elizabeth along the coast near Portland? Wow, I am surprised the cold air held on so well along the coast.
TheRasberryPatch- This image shows the jet stream configuration indicating the cold air originating from a polar vortex around the Hudson Bay. Lack of snow cover is really preventing the heart of the cold air from moving through the whole east coast.
See that high pressure bubble over the Caribbean. That is the southeast ridge being displaced. The La Nina jet stream orients itself in a manner that keeps the polar jet pretty far north due to warmer anomalies stretching northward.
Pretty much. Occasional the jet stream will buckle with a -NAO and upstream blocking allowing cold air to shift south. Usually La Nina's have 1 or 2 arctic outbreaks. But for the majority of the winter, cold air is displaced in Canada or across the Pacific Northwest.
http://www.nws.noaa.gov/view/prodsByState.php?sta te=ME&prodtype=public
Scarborough with the 10 inches is not to far from were I am.
Montgomery Co (or MDOT?) has pretreated all of the highways and main roads in Gaithersburg and Germantown. Some rain showers already came through after they pretreated.
Valdez AK December monthly total of 152.2" (12'8") is a new December record.
As of 2pm Thursday, Valdez season total to date is 321.8" (26'10), which is a new season to date record.
The 2pm Thursday snow depth was 82" (6'10").
If I were forecasting, I think I'd go 30% chance AM snowshowers Lehigh Valley - Lower Susquehanna Valley with a dusting or less. Maybe a half inch on South Mountain.
20% chance AM snowshowers southeast down to Route-1 in DE-PA-NJ with no accum.
37" snow depth today on the Anchorage cams btw.
I think the flash freeze could be pretty severe in some areas. Temperatures crash nearly 15F within 1-2 hours after a period of rain. But the thing is that they will not drop well below 29F until late in the day. Temperatures around 30-32F may be the saving grace for worse conditions. I still would expect some very poor travel conditions coinciding with some sort of squall-like feature.
From that map it looks like morning rush hour could be a problem with below freezing temps.
We'll have to get below 32F southeast of Blue Mountain by 7am when the sun comes up. I think maybe north and west of I-78 and I-81 have a slight chance.
It may be low to mid 30's at time of any changeover early morning before sunrise (4am-6am LSV?) southeast of mtns so it may be hard to tell what's frozen from rain or melted and re-frozen snowshowers at that time anyway.
I guess we'll see! That's why forecasting is fun!
We had a moderate LaNina (ONI -1.3C) for the 2010-2011 winter.
We are currently in a Moderate LaNina (ONI around -1C & trending more negative)
Moderate LaNina Mean US Winter (Dec-Jan-Feb)temperatures.
Moderate LaNina Mean US Winter (Dec-Jan-Feb) Precipitation
Now compare the average moderate La Nina to the actual conditions this winter. Nothing at all alike...
Same goes for the 2010-2011 winter LaNina and the 2009-2010 winter ElNino for the Northeast US region at the least.
This is the 1950-2002 United States composite LaNina winter (DJF) temperature anomalies.
This is the 1950-2002 United States composite LaNina winter (DJF) precipitation anomalies.
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