The Northeast Weather Blog...

Northeast Winter Forecast 2012-2013

By: Blizzard92, 5:28 AM GMT on November 09, 2012

Zachary Labe
08 November 2012
Winter Forecast 2012-2013

Many areas are beginning to clean up after another impressive coastal storm moved up the eastern seaboard with high winds, snow, and heavy rain. Heavy snow accumulations occurred in many areas from Delaware up through Maine breaking 100 year snowfall records in some locations for the month of November. Maximum snow accumulations reached as high as 13.0" in Freehold, New Jersey, but even parts of the New York City metro region saw as much as 7.0" of snow. A narrow baroclinic zone off the coast of New Jersey allowed for a period of rapid cyclogenesis as the low pressure became vertically stacked. Precipitation began to spread inland beginning as a mix of light rain/snow/sleet for much of New Jersey, New York, and Connecticut. As the surface low began to deepen sub 996mb, frontogenic forcing allowed for several mesoscale bands to form from central New Jersey up through New York City and into southcentral Connecticut.

Snow rates exceeded 1in/hr. Temperatures began to drop hovering around 32-34F courtesy of the impressive dynamic cooling responsible from the banding structures. Snow ratios remained low and in some places 4.0" of snow melted down to 0.70in of QPF. The 12 hour radar loop from last night shows the near steady position of the intense band for almost 6 hours. By later in the night, the surface low began to decouple halting further strengthening. The precipitation shield began to become a bit more disorganized and dBz returns began to wane. Once rates decreased, boundary layer temperatures began to rebound into the mid to upper 30s along the I-95 corridor and the snow began to melt from the both the bottom and top layers. Widespread tree damage has been reported throughout much of New Jersey into southern Connecticut especially given the weakened foliage post Hurricane Sandy. Fortunately, it appears a quieter weather pattern is headed our direction over the next two to three weeks. Computer models verification charts show relatively fare scores for this nor'easter with the NAM likely the most accurate in the 24 hour forecast lead time. It was able to pick up on the eastern jog and tight precipitation gradient; this is likely due to the NAM's higher resolution and hydrostatic capabilities.

Winter 2011-2012 was characterized by a moderate La Nina. The Oceanic Nino Index numbers for December through February averaged around -0.9. A strong, dominant southeast ridge flooded much of the east with warmer air preventing the classic Miller A and B nor'easters. The Climate Prediction Center's mean NAO for the winter of 2011-2012 averages out to around a peak of +2. An unfavorable Pacific and stationary Alaskan Vortex also prevented colder air from penetrating south into the contiguous United States. Much of the nation had one of their warmest winters on record in the last 30 years. Snowfall departures were also near record low values, but an early October historic snowstorm prevented many records from being broken. Across the great lakes, a multi-year drought continued with snowfall below 50" in many of the common snow belt regions. Cold outbreaks were scarce across much of the country. Looking at comparisons through the current ENSO, Asian snow cover anomalies, and teleconnections, it is evident the setup is radically different for the upcoming winter; there are very few similarities in the overall long waves pattern.

The following data will analyze the makeup for my forecast for the 2012-2013 winter. I define these months by the meteorological winter starting December 1 and lasting until March 1. Therefore my snowfall and temperature forecasts will only be for this exact three month period and will exclude any out of season snowfall (i.e. the 11/7 nor'easter and Hurricane Sandy).

Below I will define a list of common acronyms that will be referenced throughout the forecast:

Teleconnections:
ENSO- El Nino and Southern Oscillation
MEI- Multivariate ENSO Index
ONI- Oceanic Nino Index
SO- Southern Oscillation
MJO- Madden-Julian Oscillation
NAO- North Atlantic Oscillation
PDO- Pacific Decadal Oscillation
PNA- Pacific/North American Oscillation
AO- Arctic Oscillation
AMO- Atlantic Multidecadal Oscillation
QBO- Quasibiennial Oscillation
AAM- Atmospheric Angular Momentum

Miscellaneous:
BL- Boundary Layer (surface conditions)
QPF- Quantitative Precipitation Forecast
ULL- Upper Level Low
SST- Sea Surface Temperatures
WWB- Westerly Wind Burst
SSW- Sudden Stratospheric Warming
AV- Alaskan Vortex
PV- Polar Vortex
H5- 500mb height level
H85- 850mb height level
H3- 300mb height level
Miller A- Nor'easter with origins in Gulf of Mexico
Miller B- Nor'easter with origins from secondary development off NC coast
ECMWF- European Centre for Medium-Range Weather Forecasts
GFS- Global Forecasting System
CFS- Coupled Forecast System
SD- Standard Deviation
CONUS- Continental United States

Forecast City Locations (Metar Airport Codes):
KDCA- Washington, DC
KBWI- Baltimore, MD
KPHL- Philadelphia, PA
KMDT- Harrisburg, PA
KNYC- New York City, NY
KBOS- Boston, MA

Differential heating across Earth due to a variable albedo, geographical influences, unequal heating due to the curved surface, and other critical factors make the entire atmospheric column in a chaotic fluid state. But the energy budget utilizing convection, conduction, and latent heat release allow for a balance and a semi-uniform state. Therefore it is critical to note the importance of weather conditions over the entire planet. While the majority of our weather occurs in the thin bottom layer of the atmosphere, troposphere, it is equally important to note conditions aloft in the stratosphere. That area of meteorology is one of particular interest over the past few years with recent research noting warm and cold trends correlating to general long wave patterns over the northern and southern hemispheres. Below I will try to capture a picture of the present atmospheric conditions through a series of indices helpful in long term weather forecasts. Forecasting beyond a month requires a different set of meteorological skills that are unique to day-to-day predictions. Given the high variability of synoptic and mesoscale meteorology, it is impossible to produce an accurate picture of the weather conditions beyond a few days lead time. But using a combination of teleconnections, forecast models, historical analogs, and present rossby long wave patterns, we can try to capture a general education estimation for the forecast ahead. The most important part to take away from all of this are the physical connections interacting with each other on such a large scale; the butterfly effect is highly evident in seasonal forecasting. Remember the atmosphere is one giant fluid.

Before we get started, I would like to quickly define El Nino/La Nina due their importance in seasonal forecasting. An El Nino event is defined as a short term climatic event resulting in a warm phase across the equitorial Pacific. SST deviations are usually above +0.5C; the warm pool of water helps to feed increased rainfall in the eastern Pacific east towards the South American west coast. La Nina conditions are associated with a cold period as SST anomalies drop below -0.5C with warmer waters being displaced farther west. Tropical trade winds are increased as the cold pool intensifies. ENSO conditions often affect long wave patterns across a large portion of the globe and directly impact our weather in North America.


Fig. 1 shows the effects of El Nino/La Nino on surface temperatures.

The SO and MEI indices are responsible for ENSO records since 1882 during warm and cold periods and help to differentiate the two phases.

An important short term climatic index often referenced below will be the NAO. It is an index measuring pressure anomalies across the northern Atlantic Ocean. A -NAO phase is associated with a weak pressure gradient between the subtropical high and Icelandic Low. The Icelandic low is displaced to Newfoundland; the -NAO phase is commonly responsible for blocking patterns and an increase in the strength of the polar jet. A +NAO results in a stronger pressure gradient between the two circulations and results in a strong southwesterly flow over eastern North America.


Fig. 2- General NAO phase correlations to synoptic weather patterns

While the NAO is a shorter term index than other teleconnections, I strongly believe their are direct correlations to 10 year period trends This is supported by long term means over certain decades such as the 1960s ~negative NAO. More recently the NAO has also featured a long term negative trend, but again shorter term variations are common.

In a case study by Paul Kocin and Louis Uccellini, 18 sites were subdivided to reflect the impact of the NAO on cities with seasonal snowfall averaging less than 20 and greater than 40in. The results indicated the impact of the NAO on seasonal snowfall is greatest along the I-95 corridor including all of the major metropolitan areas. "Since the seasonal snowfall within this region is significantly influenced by the occurrence of moderate to heavy snowfalls, an important relationship between the NAO and the occurrence of significant snowstorms is indicated." Also Kocin and Uccellini uncovered another relationship noting the transition periods from negative NAO to positive NAO characterized by east coast cyclogenesis. For further information on this correlation check out the 1950 Appalachian Storm, 1962 Ash Wednesday Storm, 1979 President's Day Storm, 1983 Metropolitan Storm, 1993 Superstorm, and 1996 Blizzard. I highly recommend this case study featured in their "Northeast Snowstorms" Monograph. This periodical is perhaps the most comprehensive collection of research to date on winter storms across the northeastern United States and a must have for the amateur to professional meteorologist.

Winter 2012-2012 Forecast:
Looking across the equitorial Pacific, it is evident rapid changes in SST anomalies have occurred over the last six months. We have seen a gradual transition from a Nina to near Nino cycle change. The latest ONI numbers are in for ASO (August, September, October) at ~0.4. While this still represents neutral conditions, this is dramatically higher than last year at this time. But interestingly enough over the last 6 weeks, SST anomalies have began to decrease in response to an area of cooling a few hundred miles west of Peru. Latest global models are forecasting near neutral conditions during the meteorological winter. These prognostics have changed dramatically from original forecasts of a moderate strength El Nino with anomalies around +1C.


Fig. 3- Current global climate model Nino Region 3.4 Outlook

I am going to differ a bit from the current operational forecast. I have noted an increased in SST's along the central pool of water in Nino 3.4 in response to a recent weak WWB in association with the recent Kelvin wave. This is supported by the latest MEI at around +1SD.


Fig. 4- MEI means over the 1950-present period

Therefore I am expecting weak El Nino to be present throughout the first half of the winter, although its effects will be subtle. In fact looking at long term wavelength patterns as we enter December, it looks more like a Nina synoptic weather pattern over North American than a Nino.

We continue to see an anomalous cold pool over water over the northern Pacific in association with the present -PDO. This will continue throughout the winter, although its forcing may be a bit mediated in reaction to the +ENSO. This will continue to favor the development once again of an AV near the Aleutian Islands. This will focus a deep trough over the west coast of the United States. Its effects are already evident with an impressive middle latitude cyclone delivering blizzard conditions over the inner mountain west. The PDO has been steadily negative over the last 5 or so winters and was highly responsible for the progressive flow during much of the last year.


Fig. 5- NAO time Series post 1950

The NAO has recently entered a short-term negative phase. This is evident by the colder temperature deviations over the last seven days across the CONUS. We also saw two instances of strong east coast cyclogenesis, which is often correlated to -NAO phases given an amplified jet stream under blocking conditions near Greenland. Current GFS ensemble means highlight +3SD H85 temperatures near Greenland over the last seven days.

It appears this is only a short term relief to the general +NAO regime over the last 18 months. Also an extended +AMO regime has been noted across the Atlantic basin over the last twenty years. This will likely continue through winter 2012-2013. Present water temperatures off the east coast range around (+)1C-(+)3C.

The latest QBO data support a negative regime. Direct correlations can often be made between a -AO to -QBO - blocking pattern over North America. I think we will see an eventual breakdown to the persistent -QBO present in the lower stratosphere. Typically mean periods last approximately 30 days. But longer trends can be noted. The AO has also reached a sharp -2SD and has resulted in a transfer of cold air across much of Asia and Europe over the last two weeks. Snow levels have rapidly increased particularly in Asia resulting in the most widespread mean snow cover for the month of October since 2002.


Fig. 6 Departure from Normal Snow Cover for October 2012

This is perhaps the most encouraging chart for the upcoming winter. Direct correlations can be made between east coast troughing and Eurasia snow cover. It eliminates several analog years that featured low snowfall across the Northeast during weak +ENSO/+NAO regimes. It also enhances our chances of seeing a continued -AO regime and therefore reinforced blocking.

After a short recovery for Arctic sea ice, we are once again below the 2007 record low extent during the month of November.

Present monsoonal trends in the Indian Ocean support weak forcing by the MJO. This is consistent with trends over the last few months by GFS ensembles. I do not expect this to be a large factor this winter.

Present stratosphere and ozone data support a possible SSW event occurring by early December. Recent research out of several universities highlight a clear correlation between a stratosphere warm phase and east coast troughing. These SSW events though are short term, highly variable, and difficult to forecast.

While sunspot activity has been on the increase over the last two years with the advent of cycle 24, we have seen relatively quiet activity in sunspots.


Fig. 7 Solar Sunspot Cycle Monograph

Low solar activity has been directly related to periods of colder weather across the northern hemisphere. This science is relatively misunderstood and research periodicals are generally limited. I do believe given the importance of the sun in the energy budget that direct relations are likely. Looking at the latest data from the Space Weather Prediction Center, I am expecting a slightly quiet period of solar activity over the next few months.

A quick look at long range guidance suggests a mild approach to the upcoming winter. The latest ECMWF monthlies and CFS prognostics flood the nation with anomalous warmth at nearly +2SD. It is basically a repeat as far as temperature and precipitation deviations. These operational forecasts are generally low in accuracy, but interesting to look at.

Teleconnections and long term wavelengths remain relatively intermittent and do not highly lean warm or cold for temperature trends over the meteorological winter. But I think one of the more important features to look at is the previous six month's synoptic weather pattern. We are having a hard time breaking down the -ENSO pattern due to the persistent -PDO. I think we will continue to struggle with this throughout the winter. The latest H3 charts off the the global operational ECMWF/GFS are beginning to develop the AV. Whether it remains consistent will remain in question, but this portion of the forecast is critical to the upcoming winter. I am expecting low end Nino conditions, but its effects will have little impact on the general circulation. I am not sold on a -NAO regime over the next few months; in fact the north atlantic has been highly volatile over the past six months. As the -QBO begins to break down, even less support will be there for widespread blocking over the northern Atlantic.

I sort of like the winter of 2006-2007 as a possible analog for the upcoming winter, although possibly a bit warmer for H85 and BL mean temperatures. I expect a return to the amplified southeast ridge that will raise upper level heights up through the Middle Atlantic into possible southern New England. In fact the synoptic pattern may be more similar to a Nina throughout the first half of winter. Nina winters tend to run cold for December; that is important to note.

Long term trends support a lower frequency in Miller A development with a weak, progressive subtropical jet so large KU storms are not expected. Most QPF may occur in association with S/W overrunning events with possible late redevelopment off the New England coast. These events often produce a myriad of precipitation types depending on the anticyclonic conditions to the north.

In correspondance with a weak subtropical jet and generally progressive wavelength pattern, I expect precipitation to average near normal to below normal. The highest threat for below normal precipitation will stretch up through the Ohio Valley into western New England. This remains consistent with the subtle long term drought over this region.

Temperatures will be highly variable throughout the winter. It is evident by the position of cold air pools and PV relations that cold air will be more readily available on this side of the globe (unlike last winter). Therefore continental polar and arctic outbreaks can be expected, but their frequency and length will at times be limited. There will be periods of abnormal warmth under a screaming southwesterly flow during periods when the -NAO relaxes. The threat for mixed precipitation including freezing rain will be amplified this winter due to the abundance of cold air to the north strengthened by CAD (cold air damming) east of the Appalachians as overrunning systems approach from the southwest. Many shortwave and middle latitude cyclones will be fueled by a tight thermal gradient over the middle of the nation. Overrunning, frontogenically-forced precipitation events can quickly produce a quick 6-10in of snow in the cold sector, so they can have widespread impacts despite not being a MECS (major east coast snowstorm).

Overall meteorological mean temperatures will lean above normal for most all climatological reporting stations.

Winter 2012-2013 Selected City Conditions:
KDCA- (+3.5F) (75-90% of normal snowfall)
KBWI- (+3.2F) (80-100% of normal snowfall)
KPHL- (+3.0F) (80-100% of normal snowfall)
KMDT- (+3.0F) (90-105% of normal snowfall)
KUNV- (+2.5F) (100-110% of normal snowfall)
KNYC- (+2.5F) (100-110% of normal snowfall)
KBOS- (+1.8F) (110-125% of normal snowfall)

The bottom line for the upcoming winter support a higher frequency of warm spells in comparison to Arctic Outbreaks. I expect several extended periods of abnormal warmth, particularly during the second half of the winter. Snowfall estimates may be near normal to slightly above normal, but that is strongly based on the fact that the NAO may allow for several periods of blocking. If these -NAO periods do not pan out, I would expect a well below normal snowfall season. Snowfall has the highest chance for above normal deviations north of the I-80 corridor especially across southern New England where they normally do well during S/W flow events. I would expect possibly one larger MECS, but this remains dependent on the state of the NAO. Most snow will occur from other shortwave sources.

As usual, seasonal forecasts often feature lower than normal confidence and accuracy. The forecasts above are highly contingent on the state of the NAO given the general benign forcing from the other factors this year. No additional snow is expected over the next two weeks across the Northeast. Signals for any storminess around Thanksgiving remain pretty weak, so I am not convinced by any long range guidance at this point. I have heard rumbles from energy meteorologists favoring the first week in December for a possible winter storm, but this period is beyond what I can forecast. As in correspondance with my last four winter outlooks, I will post a verification blog during the beginning to middle of March.

Winter Forecast 2011-2012: Link
Winter Forecast 2010-2011: Link
Winter Forecast 2009-2010: Link
Winter Forecast 2008-2009: Link

***All images above can be found at the NOAA Climate Prediction Center, Space Weather Prediction Center, Rutgers Snow Lab, and Allan Huffman's Raleighwx Maps.

Kocin, P. J. and L. W. Uccellini, 2004: A Snowfall Impact Scale Derived From Northeast Storm Snowfall Distributions. Bull. Amer. Meteor. Soc., 85, 177-194

Follow my 24hr forecasts on Twitter... Link and Facebook... Link.

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)- 0.0in
Seasonal Total- 0.8"
Winter Weather Advisories- 1
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

Winter Forecast

Updated: 7:35 PM GMT on December 16, 2012

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November 7-8 Nor'easter

By: Blizzard92, 1:41 PM GMT on November 07, 2012

A deepening low pressure off the eastern seaboard with create nor'easter-like conditions across the Northeast over the next 36 hours. Heavy snow inland with rain and gusty winds along the coast will affect many areas greatly impacted from Hurricane Sandy condinuing to dampen clean-up efforts. Power outages with winds in excess of 50mph sustained can be expected within 20mi of the coast. Further inland across the higher elevations, up to a foot of snow is possible. Stay tuned for this major weather event!

Current Surface Plot...

(Courtesy of HPC)

November 7-8 Nor'easter Timeline and Discussion...
A deepening low pressure center off of the New Jersey coast will continue undergoing impressive cyclogenesis throughout the next 24 hours as surface pressures fall to sub 996mb. As the trough becomes negatively tilted intensification will further in association with an expanding wind and precipitation shield.

A 1032mb anticyclone over Newfoundland will tighten the pressure gradient increasing winds during the day on Wednesday particularly along the coast. Winds aloft a few thousand feet are gusting above 60 knots, and as precipitation rates increase mixing will pull these gusts down to the surface. High wind warning criteria winds are likely from southern New Jersey up through coastal Massachusetts where sustained winds will approach 50mph and an occasional gust to 65mph is expected. Already current metar reports out of Atlantic City show winds gusting to 60mph. Farther inland a more defined stable layer will limit winds to sustained around 20mph, so power outages and tree damage is not expected.

Current storm surge prognostics are indicating a water rise of 1-4 feet from New Jersey to Connecticut. A northeasterly component to the wind will allow water to pull along the favored inlets and bays including once again the Long Island Sound. The high tide of greatest concern is the Thursday morning one where water levels may approach moderate flooding in some areas. Beach erosion is expected. Overall general conditions along the shoreline can be anticipated with a moderate to severe nor'easter. Areas along the Delaware and Chesapeake Bays will generally be spared. I am especially concerned for areas along the coast in Connecticut and New York where clean up is just beginning and will greatly be affected by flooding during the Thursday morning high tide.

Rainfall and associated flooding is not a threat for any locations in the Northeast. Total QPF is only expected to max out around 1.5 inches across southern England. Given current flash flood guidance, no threats are expected.

The 500mb setup is very reminscent of a mid winter nor'easter with banana high system to the north, negative NAO, and rapidly deeping low pressure along the immediate coastline. As the precipitation shield expands inland, a stagnant but dense cooler air mass will allow for the threat of significant snow accumulations in some areas. While it is early November, the sun is not a factor and actually equivalent to an early February sun angle. Looking at the areas under the highest vertical velocity rates and omega growth, dynamic cooling will allow areas even hovering around 33-35F to change to a wet snow. For the time being the combination of best vertical lift and highest QPF will be focused across the Pennsylvania Poconos up through northwestern New Jersey. Ice crystal growth will begin to increase as the column begins to cool below -7C allowing for a period of excellent dendritic growth. Snow ratios may actually approach 15:1 for these areas. Impressive CCB banding will allow for a short period (2-3 hours) of snow rates up to 2in/hr. Snow accumulations will exceed 10in across a few locations in this area especially above 1300ft. Another area of snow concern will be across southeastern Pennsylvania including the Philadelphia metro where latest guidance suggests an impressive mesoscale banding setup that may allow areas to see moderate accumulations of snow in the range of 3-6in. Towards New England mesocale banding features will setup across the Berkshires and parts of northern Connecticut where it is possible for a period of very heavy snow with total accumulations of 5-10in over the higher elevations. Elsewhere most valley locations will see 1-4in generally over grassy surfaces and colder surfaces.

There is still a question as to how far west the precipitation shield expands and therefore the extension of any snow accumulation. For the time being I like my snow map as to a general outline of the precipitation shield. Areas farther west will have a harder time seeing accumulations despite being closer to the heart of the cold air mass as precipitation rates will be lower in association with poor ice crystal growth.

Overall the impacts of this nor'easter will be greatly felt up and down the Middle Atlantic and New England regions. It does appear the low does not linger too long and pulls out of the area by Thursday. Warmer air will also move in by the weekend allowing any snow to melt within 48 hours.

Timeline...
8am-11am Thursday- Precipitation will begin to expand west as the low pressure becomes better organized. A tight pressure gradient already in place will allow coastal areas to see gusts in excess of 55mph from Cape Cod south to Ocean City, MD. Dry air entrenched over the Middle Atlantic will allow for substantial virga with rain/snow not making it north of the Delmarva.

11am-3pm- The precipitation shield will rapidly expand as the low begins to undergo its most rapid strengthening. High precipitation rates will overcome the low dew points and dry air expanding precipitation to as far west as the I-81 corridor. Given the low wetbulb temperatures precipitation will start as a mix of rain/snow/sleet despite surface temperatures in the upper 30s to even near 40F. Before precipitation rates increase further, it may even change over to all rain before the snow especially for parts of New Jersey and southeastern Pennsylvania.

3pm-8pm- The nor'easter event will be completely underway as precipitation spreads north to NYC and rain changes over to snow across the inland areas of the Middle Atlantic. Snow rates may exceed 1in/hr over eastern Pennsylvania in this period and will accumulate especially after sunset. Winds will be gusting to high wind warning criteria force from Delaware to Maine.

8pm-12am- This period will feature the heaviest snow over the Middle Atlantic while rain falls along the coast. Total QPF alone over eastern Pennsylvania and all of New Jersey in these four hours may exceed 0.5 inches. Dynamic cooling may allow for some snow even in unexpected areas where temperatures are more moderate. High winds and waves up to 15 feet will lash against the Atlantic coast.

12am-6am- The surface low will finally begin to pull northeast spreading the greatest effects towards New England with heavy snow falling over inland areas while severe nor'easter-type impacts are felt along the immediate coast. Precipitation will begin to end over the Middle Atlantic. High tide will be approach during the end of this time period with moderate coastal flooding expected.

6am-10am- Precipitation rates will begin to lighten over the entire Northeast as conditions begin to improve. Nevertheless lingering effects will be felt much of the day.

Regional Radar...
(Courtesy of Intellicast)

Regional Advisories...

(Courtesy of NOAA)

This is my current rain/snow line...
Baltimore, MD - Dover, DE - Vineland, NJ - Jackson, NJ - White Plains, NY - Danbury, CT - Hartford, CT - Worcestor, MA - Portland, ME

***Areas north of this line will have the greatest threat of snow accumulation in excess of two inches. Many areas will see a mix of precipitation given the lack of an arctic air mass source and the time of year. Also a warm northeasterly flow off the Atlantic will keep most coastal areas predominately rain. Nevertheless snow accumulations this early in the year will cause many problems even in areas that receive a rain and snow mix.

Storm Reports...
None.

Storm Impacts...
1. Strong winds along the coast exceeding 50-60mph expected from New Jersey to New England.
2. Storm surge estimates will allow water to rise an additional 1-4 ft especially along the Long Island Sound.
3. Heavy snow rates briefly expected inland to exceed 1in/hr.
4. Quick movement of storm will allow effects to last less than 24 hours.
5. Conditions will greatly hamper clean-up efforts across the Middle Atlantic.

Snow Map...


***The highest elevations of the Poconos and Berkshires will receive the heaviest snowfall. Accumulations may exceed 10 inches in this region especially in the region located around Mt. Pocono where brief snow rates may exceed 2in/hr. Light accumulations and more mixed precipitation is expected to the coast, but a slushy 1-2in cannot be ruled out.

Current Great Lakes Water Temperatures...

(Courtesy of NOAA)

Selected City Accumulations for the Northeast...
Hagerstown, MD- Up to 1in of wet snow expected
Baltimore, MD- 1-2in of wet snow possible
Salisbury, MD- Mix of rain/snow/sleet. Snow accumulations up to 1in
Pittsburgh, PA- Mostly cloudy skies
State College PA- A few light snow showers
Williamsport, PA- A few light snow showers
Altoona, PA- A few light snow showers
Harrisburg, PA- Short period of moderate snow; accumulations 1-3in
Lancaster, PA- Period of moderate to heavy snow; accumulations 2-5in
Philadelphia, PA- Rain changing to heav snow with accumulations of 3-5in
Allentown, PA- Moderate snow expected with accumulations around 2-5in
Scranton, PA- Period of light to moderate snow; accumulations up to 2in
Washington, DC- Light rain/snow mix; Up to 1in of snow is possible
Wilmington, DE- Rain changing to heavy snow; accumulations 3-7in
Dover, DE- Rain/snow mix; snow accumulations 1-3in are possible
Trenton, NJ- Rain changing to heavy snow; accumulations 2-4in
New York City, NY- Rain briefly mixing with snow; snow accumulations up to 1in
Poughkeepsie, NY- Brief period of moderate to heavy snow; accumulations 2-5in
Binghamton, NY- Flurries
Ithaca, NY- Cloudy
Albany, NY- Light rain/snow mix; snow accumulations up to 1in
Hartford, CT- Snow changing to rain/snow; accumulations 1-4in
Concord, NH- Rain/snow mix; snow accumulations of 2-4in
Providence, RI- Rain occasionally mixing with snow; accumulations of 1-3in are possible
Worcester, MA- Brief period of moderate to heavy snow; accumulations of 2-6in can be expected
Boston, MA- Rain mixing occasionally with snow; snow accumulations up to 2in possible
Nantucket, MA- Heavy rain and high wind gusts upwards of 65mph
Hyannis, MA- Heavy rain and high wind gusts upwards of 60mph
Burlington, VT- A few flurries
Portland, ME- Light to moderate snow; snow accumulations 1-4in
Bangor, ME- Moderate snow; snow accumulations 3-6in
"Subject to Change"

Current Northeast Snow Depth and Northeast Wind chills...

(Courtesy of Wunderground)

Model Analysis
I think it will be important to focus on mesocale and high resolution models throughout the next 24 hours to look at where the mesoscale and CCB bands will set up. These areas will get some of the higher winds to mix to the surface along with the heaviest snow where I cannot rule out up to 3in per hour. The latest 4km HIRES WRF notes an impressive UVV and omega bursts over portions of southeastern Pennsylvania up through northwestern New Jersey. I really think some of the areas in this region will see upwards of 8-14in of snow. Overall model guidance is in a fairly decent correspondance although the exact track is still a bit uncertain. This will throw into question how far west the precipitation shield reaches. The SREF mean is probably the way to go for this event and allows the .1in contour as far west as 25mi past the I-81 corridor which looks fairly reasonable. The only thing the models may not be grasping in this aspect is the amount of dry air present over the area. Dew points are in the low 20s for many areas this Wednesday morning. Overall the ECWMF scores highest on the verification charts for spotting this threat, but was certainly overamplified therefore pulling a track too far to the west. The GFS did a fairly nice job, and throwing out is progressive nature bias, I will be interested in seeing the actual accuracy charts from the NCEP. The HRRR simulated radar already has a fairly good hold on this system; keep in mind as we advance in time that the composite radar often pulls precipitation too far to the west. I will be posting near term model updates throughout the day.

After the Storm
The latest NAEFS prognostics in association with changes in selection teleconnections are signaling a pattern change for the next coming two weeks. The NAO will begin to tip towards the positive scale again deamplifying the polar jet into a more progressive and zonal flow. This is also in correspondance with a -PNA forming across the Pacific. Latest monsoonal maps out of the Indian Ocean indicate the MJO rotating through phases the support ridging across eastern North America particularly in the southeastern United States. Meanwhile very cold air will begin to drop down across the Rockies and inner mountain west in association with a steep trough that will leave plenty of snow in the higher elevations. This will be good news for water tables after an ongoing mult-year drought.

The milder temperatures and drier air will flood the east coast in the rough estimate period of November 11-20. Latest long range prognostics report the MJO coming around to phases 7,8,1 by Thanksgiving along with a return to a -NAO. This may signal another cooler air mass towards the end of the month. Unlike the current nor'easter that was spotted nearly two to three weeks in advance, there are no signs of any long range major winter storm at this point.

In general I expect November to average slightly above normal given means around +4 compared to normal are likely during this two week warm spell. My next blog, since the weather finally begins to quiet, will be my winter forecast for the meteorological winter for 2012-2013. While it has been delayed later than normal this year, that has helped solidify a slightly higher confidence forecast. This blog can be expected within the next seven days. Stay tuned!

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...

Follow my 24hr forecasts on Twitter... Link and Facebook... Link.

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)- 0.0in
Seasonal Total- 0.0in
Winter Weather Advisories- 0
Winter Storm Warnings- 0
Ice Storm Warnings- 0
Blizzard Warnings- 0
Freezing Rain Advisories- 0
Winter Storm Watches- 0

(Temperature Stats)
Lowest High Temperature- ---
Lowest Low Temperature- ---
Wind Chill Advisories- 0
Wind Chill Warnings- 0

(Snow Storms Stats)
None

Winter Storm Blog

Updated: 3:32 PM GMT on November 07, 2012

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Nor'easter #2 looming?

By: Blizzard92, 12:01 PM GMT on November 02, 2012

"Current Northeast Surface Station Plots"


"Current Surface Map and Weekly History of Jet Stream Position"


"Regional Radar"


"Regional Satellite"


"Regional Advisories"


"Soil Moisture Anomalies and 5-day Precipitation Amounts from Hydro Prediction Center"


"Seven Day Departure from Normal Precipitation"


"Forecast Max Temperatures"


"Forecast Min Temperature"


"Forecast Weather at 2pm"


"Severe Weather Outlooks from Storm Prediction Center Days 1, 2, and 3"


"Current Storm Reports"


"Fire Outlooks from Storm Prediction Center Days 1, 2, and 3"

(All maps courtesy of NOAA and Penn State Meteo.)

"Forecast Model Links"
-NAM model 12z...Link
-GFS model 12z...Link
-NMM model 12z...Link
-SREF model 9z...Link

"Severe Weather Links"
-Atmospheric Soundings Skewt T charts...Link
-SPC Mesoscale Analysis Pages...Link
-Public Spotter Reports for State College NWS...Link
-Severe Weather Model Forecast indices...Link
-Severe Weather Parameter Definitions...Link

"Flooding Links"
-Automated Pennsylvania Rainfall Recording Stations...Link
-Flash Flooding Guidance...Link
-HPC Forecasts for Excessive Rainfall...Link
-Hydrology Predictions for Lakes, Rivers, and Streams...Link

Lower Susquehanna Valley Doppler...

(Courtesy of WGAL)

Follow my 24hr forecasts on Twitter... Link and Facebook... Link.

Observation Blogs

Updated: 6:01 PM GMT on November 04, 2012

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About Blizzard92

Cornell University- Atmospheric Sciences Undergrad; Research Assist.- Onset of Spring Indices Toolbox; Interests- Small spatial scale climatolology

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