Ph.D. Student - Earth System Science (UC Irvine), B.Sc. - Atmospheric Sciences (Cornell University)
By: Zachary Labe , 2:01 PM GMT on December 13, 2011
"Afternoon Thoughts" (Updated 12/13)
I have 1161 friends. Yes you heard me... 1161 friends.
Okay, only Facebook Friends. In this age of 'to the second media' updates, social media has exploded and is popular daily conversation. From status updates to looking at one's latest vacation pictures, our lives have become public. While Facebook surely can be argued for many benefits from rekindling past friendships to strengthening long distance family bonds, there are also plenty of consequences of such social media.
I certainly do not know all 1161 of my Facebook friends personally, in fact only a small margin of them would actual be considered a real friend. Social media has radically altered the definition of a 'friend.' Instead of a few birthday cards from close friends, we now receive hundreds of 'happy birthday' messages. Or instead of sharing photographs from one's wedding, they are now shared with the world. We have published our lives on the internet to the point where one must constantly worry what is being put as a status or picture.
A Facebook friend does not satisfy a real friendship built on trust and social interaction. And now we have reached a point where even a phone call is just too much hassle from our daily routine.
There is no reason to share every detail of our private lives with the entire world. There is no reason to replace a Facebook friend with a real Friend. Social media has opened many doors with many benefits, but it has replaced the simplest of concepts. A friend.
"Current Surface Plot"
(Courtesy of HPC)
(Courtesy of Wunderground)
(Courtesy of NOAA)
"Forecast Discussion"(Updated 12/13)
A deepening surface low moving up through the Great Lakes will be the primary weather story for much of this week. A southerly flow aloft ahead of the digging energy in the southern Mississippi Valley will allow high temperatures to rise to above normal values during the day Tuesday with sunshine courtesy of an anticyclonic flow. High pressure will shift to off the coast of Maine as a low pressure in the Midwest gathers strength. Warm air advection aloft will allow for light precipitation to form along a boundary across the northern Middle Atlantic by Wednesday evening. Given the timing over the night time hours, some light freezing rain is likely over the colder valleys of Pennsylvania and New York state. Amounts will generally be minimal and less than .1in. H85s will rise to above 5C with little to no snow/sleet expected. A screaming southernly low level jet will enhance precipitation by early Thursday morning from the Middle Atlantic to New England. The departing cold air mass will allow for some light frozen precipitation over northern New England with snow/sleet amounts from 1-3in over northern Vermont, northern New Hampshire, and Maine. But even those locations will transition to rain given the strength of the LLJ. Strong southerly winds are also likely across the higher elevations and may reach advisory criteria as gusts approach 40-45mph above 1800ft. Surface maps continue to indicate a high pressure gradient as the high slowly departs northeast. The heaviest QPF will fall in the right front entrance of the LLJ across New York state with up to 1in of rain expected. Lighter amounts are likely along the rest of the cold front generally ranging from .25-.5in of rain. As the low deepens to sub 992mb over Ontario, the cold front will quickly move through the Northeast with falling temperatures and cold air advection. H85s will drop below 0C with residual snow flurries and snow showers likely from lake effect. Increasing dry air will likely prevent widespread lake effect streamers from forming. See more in discussion below.
High pressure over much of the contigous United States will allow for a dry and clear weatherwise few days by Friday under a seasonably cold air mass. Temperatures will generally be near normal for the time being. A weak wave will move to the south of the Middle Atlantic late Friday into Saturday with only light cirrus expected across the Maryland and Washington DC region. All in all low chances for wintry precipitation except for slight chance of freezing rain and frozen precipitation for northern New England midweek and some light snow from the lake effect machine across the snowbelts on Thursday/Friday.
(Courtesy of Penn State Meteo.)
"Current Water Vapor Loop"
(Courtesy of Penn State Meteo.)
"Lake Effect Snow Conditions" (Updated 12/13)
For those tracking the potential lake effect snow event this past week around December 10, it was pretty much a dud. Limited instability was available given only a 8C differential between air and water. Due to above normal SST across Lake Erie and Ontario, it had appeared that lake effect snow bands would develop none the less across the region under first a 250 degree flow shifting to 290. This would allow two streamers to form across upstate New York across the Oswego to Watertown area and through the Buffalo metro area up to Niagra Falls. A shortwave also moved through during this period enhancing light synoptic snow across western New York, although amounts were generally a dusting. Low instability and other poor parameters prevented the expected heavy streamer from forming particularily off Lake Erie. A weak band formed during the diurnal period, but given 2m temperatures in the mid 30s, many areas only received a rain/snow mix. The band generally stayed north of the Buffalo metro with amounts around 4-5in towards Niagra with only an inch at the Buffalo airport. As the flow began to shift more westerly, the band off Erie dropped back south across the metro with an additional inch or so. This was well below the expected 5-9in of warning criteria snow forecast.
The following 24 hours allowed for a more west-northwest flow with the Erie band settling over towards the Chatauqua Ridge and Jamestown region with areas receiving a fresh 6in of snow or so. The band off Ontario was a bit more intense with 1-2in/hr snow rates. It generally remained north of the Oswego area with amounts up to 12in reported in the Tug Hill. Both bands began to die Saturday night as drier air from an area of subsidence began to lift northward shearing apart the snow bands.
There is a very low threat of significant lake effect snow this week even given the expected cyclonic flow post great lakes cutter. H85s will drop from above 0C to around -10C after the cold front passes through with winds shifting to around 300 degrees. There will be a great deal of dry air and a slight CAP preventing organized streamers from forming. A few snow bands are likely to still form, but only advisory amounts or less are likely for most all locations. It appears most of the lake effect snow diurnal activity will be limited to New York state given an area of subsidence over Pennsylvania. The more northerly flow may allow a few areas to see some light snow accumulation across western New York where this is a significant snow drought especially across much of the Finger Lakes region. By late Friday, dry air and low level shear will cutoff the lake effect snow machine with a quiet weekend weatherwise.
"Current Great Lakes Water Temperatures"
(Courtesy of NOAA)
-Link to official river ice reports page from NWS... Link.
-Link to local ski resort snow conditions... Link.
"Current Northeast Snow Depth and Northeast Wind chills"
(Courtesy of Wunderground)
"Long Term Outlook" (Updated 12/13)
A slow pattern change is now evident on most teleconnection indices. A SSW (sudden stratospheric warming) event is now slowly ongoing on the Asian side of the Arctic. The statosphere is close relately the AO and position of the PV. Over the last few months, the statosphere has recorded near record cold mean temperatures, but signs of a slow warming trend on now ongoing. This may lend hand to an excellent January for winter lovers if all goes as planned. The SSW will likely relax the positive anomalous arctic oscillation and help to slowly reposition the polar vortex, which appears to be slowly moving towards the Atlantic. This will hopefully begin to open the floodgates to the Arctic by late in December. Current ensemble guidance supports the heart of the cold air centered around Christmas day give or take.
The current seven day mild period we are in for the time being was my outlined mild period in mid December. The pattern is very hostile and serves little to no potential for snowfall over the next 7 days for most locations east of the Ohio Valley except for possibly far northern Maine. Looking below at my December outlook issues back at the end of November, conditions are lining up almost perfectly as far as the development of the month of December. This second mild period currently should give way to a colder period late month. The MJO is showing signs of dwindling significance as ensemble and operational guidance suggests it may be headed into the circle of death with lower wavelength impact after traversing through unfavorable phase 5. ECMWF ensemble support is beginning to show signs of a negative NAO, but it remains east based in the long range. Looking at storm chances, there are a few dates of significance especially towards the 21-22 of the month. Given the continued hostile pattern, it is more likely this system is a significant snowstorm for parts of the Great Lakes or Ohio Valley. None the less there is the potential for overrunning wintry precipitation in the northwest given the similarities to a southwest flow event. Also towards Christmas, there is the potential for a storm system, but less certainty on long range guidance. Temperatures will remain above normal for the next seven days with a lowering trend towards Christmas with possible below normal temperatures. Snow chances remain minimal for the shorter term.
"Current NAO and PNA Predictions"
(Courtesy of NOAA)
"Anchorage, Alaska Tower Cam"
*Back due to popular demand!
"Monthly Temperature/Precipitation Outlook"(December)(Updated 11/29)
Many winter forecasts made back in the mid fall analyzed December as being the coldest month of the winter for much of the east coast. But now given the state of many global teleconnections, it appears December will continue the string of above normal temperature months. The month will open with a raging +AO nearly at 3SD and may be approaching a high in the first two week period. Corresponding with a +NAO, there will be little to no blocking associated over the Northern Atlantic. While the Atlantic remains dreadful, the Pacific is a tad more favorable early month with a return to a -EPO and +PNA favoring a west coast ridge. The MJO has been one of the driving factors in current wavelengths with phases 3-5 being traversed early in December. As the month progresses, there are signals the MJO heads back into unfavorable phases 2-4 and the EPO returns to a raging positive anomaly. This will allow for a mid month warm spell favoring the east coast and upper Great Plains. Around 12/20 or later, there are a few undefined signals indicating a sudden stratospheric warming event which may help to dislodge the positive NAO. Corresponding with a quieter sun towards the beginning of January, a return to slight blocking across the North Atlantic will be possible in this period.
Temperature- Temperatures will range well above normal on average for the month ranging from (+1.5F)-(+2.5)F for most climatological reporting stations. Temperatures will be seasonable to slightly above normal for the first week or two of December. While slight transient cold waves are possible, they will last only 1-3 days at most. By mid month a possible transition to a milder pattern is possible with well above normal temperatures. Approaching late in the month towards Christmas, there is a chance of a return to a colder regime as we get closer to January. This may allow for seasonalable to slightly below normal temperatures. There remains a great deal of cold air on our side of the pole through December, so whenever or if this pattern changes, there will certainly be quite an arctic blast.
Precipitation- A relatively active subtropical jet stream considering we are in a moderate La Nina regime will continue to allow for the development of storm systems across the southern states. Given the lack of blocking, many of these storms will cut to the west of the Northeast putting most locations in the warm sector. While there will be a few periods for colder air across the east coast, timing will need to be perfect to get a snowstorm. In general this pattern is terrible for Middle Atlantic to receive any snowfall. I do believe though there will be 1-2 synoptic events which may allow for near normal snowfall for many locations. If these do not occur, it will be a mild and snowless month. Given the lack of sustained cold air, even the lake effect machine will remain quiet for the most part. Precipitation in general will average near climatological norms.
"Temperature and Precipitation Outlooks from Climate Prediction Center for next 30 days"
(Courtesy of NOAA)
"Local Harrisburg Radar"
(Courtesy of WGAL)
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"10mi northeast of Harrisburg 2011-2012 winter statistics"
Current Snow Cover- 0.3in
Monthly Total (October)- 5.5in
Monthly Total (November)- 0.0in
Monthly Total (December)- 0.3in
Seasonal Total- 5.8in
Winter Weather Advisories- 1
Winter Storm Warnings- 1
Ice Storm Warnings- 0
Blizzard Warnings- 0
Freezing Rain Advisories- 0
Winter Storm Watches- 1
Lowest High Temperature- 39F
Lowest Low Temperature- 17F
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
The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.
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