Ph.D. Student - Earth System Science (UC Irvine), B.Sc. - Atmospheric Sciences (Cornell University)
By: Zachary Labe , 8:00 PM GMT on December 14, 2008
"Afternoon Thoughts" (Updated 12/14)
Good Sunday evening!!! I doing a look back through some of my blogs from last winter; trying to do a catch up to get myself back in the winter storm routine. And looking back through I found my settings for when I first joined Weatherunderground and found it to be December 14, 2007, exactly one year from today. It does not seem like I have been posting here for already over a year, even though this is my 91st blog and nearly 5000th comment. I have thoroughly enjoyed my posting here and have met some wonderful people, none of which I have ever had any problems with. For oldtime's sake here is a link to my first blog... Link. I am looking foward to another great year here at Wunderground and look for a special blog to appear when I reach my hundreth blog, which will be coming up this winter. Thanks again for everyone's wonderful comments that I look forward to reading each one. We have been through a relatively quiet weather pattern in the past year other than the ice storm in December of 2007, but really no big severe weather outbreaks, tropical systems, winter storms, or flood events; so lets see what this coming year will bring!
So the most dreaded brown landscape has hit Pennsylvania where mountains are coated in brown with little signs of life. Streams become ice coated on the sides as water comes pouring out of the mountains from melted snow. Back dirt roads become mud pits from the constant precipitation, and automobiles become coated in the white coating from the local township salt solutions. It is winter, thankfully though the flavor is a bit higher thanks to all of the Christmas decorations. But soon it will be January, the depressing time of the year especially with any lack of snow time period. Still though I enjoy those drives through the mountains and backgrounds taking in the beauty of what is left in this world that is not cemented over. Then the snow hits and cleans the surrounding landscape and as shoreacres already mentioned, the snow creates a buffer from the rumbling of the nearby urbanized areas. It still though just not feel like it is winter already; I feel like Summer has ended yet, and Fall has just picked up with Summer left off. But it will soon officially be Winter according to the astronomic calendar, and for those who dread this season every year, we have a wonderful 4.5 months of it to come. While I must admit Winter is my favorite time of the year, with all of the cool brisk winds and the calming snowflakes next to a warm fire. It is the season (well after the holidays) that is most relaxing where all one can do is sit by the fire and read a novel and tell a story from one's past. But for us snowlovers and weather observers it is the most hectic time of the year full of wild mood swings as good model runs show arctic blasts while the next model run shows heat boiling up the eastern seaboard. Rain/snow lines causes headaches and sometimes there are those forecasts where the chance of snow looks high only to be followed by a drizzle of rainfall or the other scenario of waking up to 6inches of "partly cloudy" on the driveway. But rain or snow, I think we all love the heartaches the winter gives us each and every year. But as an anonymous poet once wrote...
Whether the weather be fine,
Whether the weather be not,
Whether the weather be cold,
Whether the weather be hot,
We'll weather the weather,
Whatever the whether,
Whether we like it or not.
"Current Surface Plot"
(Courtesy of HPC)
(Courtesy of Wunderground)
(Courtesy of NOAA)
"Forecast Discussion" (Updated 12/14)
Since another complex weather week is in store with frontal placements that could make differences between rain/snow; I will only issue discussions and forecast for the day before the weather day. So here is Monday's discussion. Strong southwesterly winds will draw up warm, moist air from the Southeast giving PWATs to a few deviations above normal for this time of year. H85s rise to above freezing statewide, but only manage to get near +5C as a max across the state. Boundary layer temperatures though do manage to rise to near 60 degrees near the Mason-Dixon line. A potent front approaches the region with light QPF of near .25-.35inches for the entire event and weakening as it moves eastward. Cold air initially is very chilly, but the core of the cold air stays well over the western United States. Front comes crashing through overnight Monday with 0C 850 isotherm passing through all of Pennsylvania and hanging up around the Mason-Dixon line along with the front. Southeast ridge will prevent the front from digging farther south. The placement of the front will pose issues for the rest of the week in terms of precipitation types as several waves ride up along the front for forming some overrunning events.
(Courtesy of Penn State Meteo.)
"Current Water Vapor Loop"
(Courtesy of Penn State Meteo.)
"Weekly Forecasts" (Updated 12/14)
Monday- Warm, southerly breezes will prevail with gusts upwards of 30mph at times possibly gusting to 45mph on some of the higher southern facing ridge tops in the central Ridge and Valley region. Warm air will rise up the east coast giving way to mild high temperatures approaching 60degrees for the southern Pennsylvania border counties. Highs elsewhere will generally be in the 50s statewide. With snowpack over some areas and a slight easterly flow during Sunday night, there will be areas of dense morning fog across the east half of Pennsylvania, which will likely thin out, but still linger throughout the day. A cold front will approach the region with rain showers statewide. Rainfall amounts do not look overly impressive with amounts topping .25inches in most areas across the northern half of the state with lighter amounts across southern portions. Monday night more rain will be across the state, but amounts will generally be less than .1inches. Temperatures will be falling through the frontal passage with lows in the 20s across the north and 30s elsewhere. With a breezy northerly wind there could be a brief lake effect snow squall near Erie with 1-2inches of snow possible mainly along the lake shore. Scatted flurries generally elsewhere in the snowbelt regions of the state. Overall looks like a mild and damp night for Monday night for all areas south of I-80.
"Current River Ice Reports and Ski Conditions" (Updated 12/14)
We definitely have had some brutally cold weather during the past few weeks from mid November onward through mid December bringing river ice record early to some locations. Just the other week sheets of ice were floating down the mainstream Susquehanna River with other small waterways such as the main stem Swatara Creek which was completely frozen over. But with the rain from the past storm and a brief period of mild temperatures, much of the mainstream waterway ice has melted. But farm ponds remain iced over for many locations especially across northern Pennsylvania where it was actually getting thick enough to stand over for a time period. But with the recent spell of rain and warm temperatures, it is once again becoming unsafe to step onto the ice. Hypothermia and frostbite are major threats when outside in these types of conditions during the night especially if you get wet in the water, where temperatures are in the 30s. Ice fishing is not permitted currently as ice is not near enough even for cold mountain lakes above elevations of 1700ft on the north sides of mountains. But with the approach of January some small ponds may begin to get thick enough for ice fishing. Looking at ski reports most all ski resorts are opened for the 2008-2009 winter season reporting an average base of around 25inches statewide. Many ski resorts have had record early starts to the season this year with plentiful days for snow making. Parts of the Laurel Highlands have already picked up 50inches of natural snow along with snow making from the ski resorts making for wonderful conditions, especially for this time of year. Looking a ski conditions this week, they do not look to good for all locations across Pennsylvania with periods of rain and warm temperatures followed by wintry mixes. Some locales though may pick up several inches of natural snow this week, but the exact locations remain to be seen. I would say the best location for skiing this week would be in the Poconos where they could see some natural snow along with being north of the cold front keeping locked into the colder air than some areas to the south. Colder air looks to move in for the start of the end of the weekend into early next week with an arctic blast possibly resulting in some lake effect snows and snows from a clipper. Towards the holidays it would suggest to me that conditions will be pretty decent across the state for snow conditions at the resorts and lodges.
-Link to official reports page from NWS...Link.
-Link to local ski resort snow conditions...Link.
"Current Northeast Snow Depth and Northeast Windchills"
(Courtesy of Wunderground)
"Lake Effect Snow Conditions" (Updated 12/14)
For once a quiet lake effect snow pattern is in effect this week. The week remains fairly unsettled with a stalled front over the region limiting any sort of northwest flow. I find it interesting that this winter's snows have mainly been lake effect across Pennsylvania. We really have yet to see any major snow producers other than a few locales in the higher elevations in northern and northeastern Pennsylvania. Even for southern areas this winter has mainly be snowfall from lake effect with only one other snow producer of a weak clipper that produced from .5-2inches of snow across southern areas. The only period this week for possible lake effect is late Monday night through early Tuesday morning in which winds will be out of the north-northeast. Easterly component will limit lake effect as trajectory will be near 25degrees. But a few bands may affect parts of Erie County near the Lake Shore. H85s will be below -5C along with some decent Omega and dendrite growth, but wind direction will be the inhibiting factor, so I will leave a 1-3inch snow swath through Erie and Crawford Counties during this time period. This should be nothing out of the ordinary for winter for locations up that direction. Looking at water temperatures for Lake Erie, they are beginning to drop pretty steadily all in the 30s with some low 30s across the southwestern shore in Ohio near Toledo with a bit of ice formation. The highest water temperatures remain in the deep part of the lake along the New York State shorelines getting into the low 40s in the deeper channels. If we can get a cold pattern to resume by late month I would expect heavy ice formation this winter on Lake Erie possibly freezing over, but with a warm period expected by the mid to end of the month, that remains to be seen for any freezing over type talk.
"Current Lake Erie Wind Direction and Speed"
(Courtesy of NOAA)
"Current Lake Erie Water Temperature"
(Courtesy of NOAA)
"Long Term Outlook" (Updated 12/14)
Well here I go, this will be a pretty depressing outlook for snow lovers. It seems to me after that the La Nina pattern is returning, though not quite with the vengeance of last winter. Sea surface temperatures have cooled in the Central Pacific to near -1C below normal. While it does not seem significant, it is low enough for significant changes on the overall global weather pattern. While this was not unforeseen... Last year the winter was highly dominated by a very strong La Nina, which caused an unusual jet stream favoring very heavy snow north of I-80 also causing a very active storm pattern. Looking over some of the latest data I have come up with this conclusion. Neutral conditions will persist through the Fall of 2008. Come the winter months of December, January, and February conditions will generally be near neutral slightly leaning towards a weak La Nina That was from my winter outlook. Officially the Climate Prediction Center has not termed this pattern La Nina, they call for neutral conditions to persist through January of 2009. But it does appear weak La Nina affects in the atmosphere will occur for the winter months. In the past weak Ninas have favored some snowy conditions across the state with infamous winters such as 95-96 being a weak Nina winter. But there are always exceptions. On some of the latest models runs I have seen the western Atlantic ridge showing signs of moving our direction along with the development of the southeast ridge. The optimistic part is the southeast ridge gave many areas to the north of I-80 last year the heaviest snow thanks to the strong ridge. This year there does appear to be the influence of the ridge, but not near as strong. If that happens we could have some interesting overrunning type snow events for areas farther south giving areas north of the Mason-Dixon line the best chance for accumulating snows. Looking back to my winter outlook that is basically how my jet stream went. But if we get to strong of an influence, this winter could not be a very nice one to all of us here in the Northern Middle Atlantic. Among many indices another one unfavorable for the time being is the MJO, which is staying in phase four or edging into phase 5. Here is a composite for mean anomalies during phase 5 during the winter months... Link. Obviously it is not favorable for much of the nation east of the Mississippi with large ridge over the region. We have been in phase 4 for the MJO for an extended period of time which made the Atlantic unfavorable, and that is thanks to the lack of snowstorms here in the east. This pattern looks to continue. The only thing to offset it would be a negative NAO, which looks to make a retreat back from positive to negative right before Christmas. PNA on the other hand wants to stay negative favoring troughing over the west. AO index has been fluctuating every day but does show a return to negative coming towards the end of the month. So my overall conclusion for the next two weeks is a seasonable to above normal temperature for the most part. I think there will be a brief period before Christmas of colder than normal temperatures. Snowfall should definitely be lacking all across the Northeast and not just the Middle Atlantic. So will this be the pattern for the rest of winter? There is no way of telling, but I still feel this is just a balance of equilibrium giving the other parts of the world colder anomalies, and that things will shift back. This winter was never going to be an easy one to predict like last winter, in which there was clear evidence for a warm winter. This winter had no clear evidence to support either warm or cold, but the overall pattern showed a cold regime. So overall keeping optimism held high, and remember two things...
Winter has not really officially started...
And December is the least snowy of the winter months...
"Current NAO and PNA Predictions"
(Courtesy of NOAA)
"Monthly Outlook" (December)
So here it is the first month of the meteorological winter, and quite hard to believe at that. It feels like we were just watching severe thunderstorms role across the heartland and hurricanes roar across the Gulf of Mexico. But now it is our season for extreme weather; winter storms. Looking back at my November Outlook I called for normal to below normal temperatures with normal precipitation. That is very close to what actually happened and with the temperature department I nailed it spot on. Temperatures for the first half of the month were well above normal and by the second week temperatures plummeted to the coldest temperatures we had seen in November in quite a long time. Temperatures average below normal by a few degrees, but it could have been an even bigger anomaly if we had not seen that very warm outbreak in the beginning of the month. Snowfall I called for normal snowfall to above normal snowfall, and many areas across Pennsylvania are running 150% above normal in the snowfall department. The only area really lacking snowfall is in the Lehigh Valley where they have only seen a few coatings, even the Philadelphia snow season is starting off with a bang. Some areas in the snow belts near Erie have seen some of the snowiest weather in November in decades. Precipitation as a whole though was slightly below normal to normal in most areas. It seems we have been caught in a somewhat drier pattern lately in comparison to other years, still though we are far from a drought. So for December here is what I see…
Temperature- For quite a few months as far back as August, December was looking to be an extremely cold weather in comparison to normal. Now as we approach December, very little has changed in that regard. I am forecasting below normal temperatures across the entire state. Now the anomaly will not be extreme, but it will be enough for a couple of degrees below normal as a whole. I am expecting very cold weather for first week or two of December, before a more rollercoaster type pattern with cold followed by warmth. Then for the end of the month I think the coldest air moves over the Northeast with the coldest weather possibly of the whole winter. There are teleconnective signs of a decent negative NAO that would favor deep troughs over the east coast. But there are a few discrepancies with the models with some favoring a western Atlantic ridge and warm air up the east coast. But I still think the models think we are in a stronger La Nina pattern than we actually are. Just recently the climate CFS model which was forecasting a strong La Nina again, has now backed up to a weak La Nina which is more reasonable. I must also mention that now the CFS shows below normal temperatures across Pennsylvania for every meteorological winter month. All in all I think December will favor below normal temperatures with even some more favorable blocking scenarios towards mid to late month.
Precipitation- Lately we seem to have been in a drier spell, so I find it hard to forecast above normal precipitation. So my forecast calls for normal precipitation with above normal snowfall. Looking at all of the global models, the ECMWF, GGEM, and GFS they all forecast a much stormier weather pattern starting the second week in December and lasting for quite a while. The northern jet seems to become the focal point of all the weather with storms even coming into the northern US Pacific coast and traveling transient across the nation and out to sea in the Middle Atlantic. At times there may be phasing between the northern and southern jet, which could lead to some strong winter storms across the central and eastern US. I also believe the pattern favors many Alberta clippers in which some of them could even be Saskatchewan screamers. Lake effect machine may end towards later in the month as Lake Erie may freeze over this winter, especially with how the pattern is looking. Warm air advection snows are also possible.
"Temperature and Precipitation Outlooks from Climate Prediction Center for next 30 days"
(Courtesy of NOAA)
-Winter 2008-2009 forecast... Link.
-Winter 2008-2009 forecast update... Link.
"Here northeast of Harrisburg 2008-2009 winter statistics"
Current Snow Cover- 0.00inches
Monthly Total- 0.75inches
Seasonal Total- 6.85inches
Winter Weather Advisories- 1
Winter Storm Warnings- 0
Ice Storm Warnings- 0
Blizzard Warnings- 0
Snow Advisories- 0
Winter Storm Watches- 1
Lowest High Temperature- 26
Lowest Low Temperature- 14
Wind Chill Advisories- 0
Wind Chill Warnings- 0
(Snow Storms Stats)
First Snow - October 29 - Trace
First Snow on Ground - November 18 - Coating
Lake Effect Snow - November 21/22 - 6.00inches
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