Cornell University- Atmospheric Sciences Student; Central PA SKYWARN Storm Spotter; American Meteorological Society Member; PA CoCoRaHS Branch Member
By: Zachary Labe , 8:44 PM GMT on November 02, 2010
"Afternoon Thoughts" (Updated 11/02)
Through my entire education I have been taught a set structure for writing essays. Always begin with an AGD (Attention Getting Device). Usually they would advise posing a question, statistic, or quote to support the AGD. Then add a thesis statement (topic sentence). Always make sure the thesis statement is three prong. This means state the topic and add three points in the sentence to support the topic. Example: I like the weather because it is fun, cool, and exciting. Of course that would be a terrible thesis statement, but you get the point. Then write a body paragraph to support each of the three examples. Finally write the last paragraph as a conclusion. This is the typical 5-body paragraph that my teachers have emphasized since my very beginnings of middle school/high school English class. While this is all fine and dandy, the problem is a set structure. Typically, I do not associate writing with one of my hobbies, but I cannot say I hate it either. In any case writing should not follow a set pattern. This does not mean writing an essay should consist of no structure or pattern. But who is to say it has to follow five paragraphs and have a three prong thesis statement. Often I find these over-structured papers to be dull and boring. Writing is self-expression like any art form... music, painting, etc. It should begin with an acknowledgement of one's idea with supporting details in the form of expression, like a conversion. If I was to do a research paper on lake effect snow for English class, it would probably be advised to follow the five-body paragraph plan. But I would stray from that, using a more unique approach while still having an interesting introduction and conclusion with a thesis statement. But there would be a twist and not so much of a cookie-cutter approach. Everything in the world seems to always be a structured approach. Yes, this keeps things organized, but it is not always the answer to everything. Sure, it would be simple to go through a checklist to figure out whether a nor'easter would affect Washington DC or not, but unfortunately forecasting is more than something fitting X,Y,Z. Just like a snowflake, no two are alike. I can say well this winter will be like X, but in reality there will not be too many similarities. But back to the original point, you do not have to pierce your body all over and die your hair pink to be 'different' or 'unique;' all it takes is a bit of character and not being afraid to bend societies set boundaries.
"Current Surface Plot"
(Courtesy of HPC)
(Courtesy of Wunderground)
(Courtesy of NOAA)
"Forecast Discussion"(Pennsylvania, Maryland, Delaware)(Updated 11/02)
High pressure is stationed across the northern United States allowing for a cool airmass to remain over the Northeast. H85 thermals around -2C and 1000-500mb thicknesses near 538dm will translate to surface high temperatures on Tuesday and Wednesday to range about 5-8F below normal. Widespread sunshine is likely on Tuesday with only some high cirrus. Tuesday night will feature very cold temperatures across the entire northern Middle Atlantic. 2m GFS/NAM dewpoints range in the upper 20s to low 30s by evening and fall into the mid 20s overnight north of 40N. With clear skies and decoupling winds, cool air will sink into the valleys for ideal radiational cooling. Favored radational cooling locations such as in northern Pennsylvania in McKean, Potter, and Tioga Counties will drop in the upper teens. The northern half of Pennsylvania in the Alleghany Plateau region will be in the lower 20s with the central ridge and valley region in the mid 20s south to about the Lower Susquehanna Valley. Towards Philadelphia the suburbs will drop in the upper 20s with low to mid 30s for the city center. Across Washington DC, Maryland, and Delaware suburban regions will be in the mid to upper 20s with 30s for city centers. Across western Maryland towards Garret County and Alleghany County, a few low 20s are possible. This is the second night in a row for a regionwide killing frost. Wednesday, the surface high move eastward allowing for a bit more southerly component to the winds aloft. This will bump high temperatures up a bit into the low to mid 50s for locations north of the Mason-Dixon line and mid 50s to upper 50s south into Maryland and Delaware. Across the higher elevations above 1200ft, temperatures will be in the 40s. Sunshine will dominate the region, but some mid to high level clouds will approach from the southwest by early evening. A deepening trough over the mid center of the CONUS will begin to slip eastward. Tropical moisture along the eastern periphery of the trough axis will phase with an approaching upper level low. This will develop a low pressure just north of Cape Hatteras, NC. GFS is my model of choice remaining of highest consistency. ECMWF and GGEM were over-amplifying earlier runs allowing for a slightly inland track. But GFS has remain consistent on a weak 850hPa low tracking a bit farther off the coast by about 100-300mi. By 12z Thursday, GFS/NAM prognostics indicate a 1004mb 850hPa surface low off the coast of the Delmarva with light QPF thrown back into the northern Middle Atlantic. It remains in question of how much QPF is thrown back to the west. SREF probabilities show measurable QPF back to about the Hagerstown-Altoona line. This is in close agreement with GFS QPF fields. Accounting for some initial dry air, about .05in can be subtracted for QPF totals. The NAM is a bit different in its output, showing the surface low farther off the coast with most of the moisture occuring along the trough axis as it approaches the region Thursday night. At the time the NAM prognostics seem to have a few convective feedback problems and basically a messy surface output. QPF fields will be disgarded. ECMWF is slightly similar to the NAM with a washed out approach before the low undergoes cyclogenesis off of Nantucket. H85 thermals remain above 0C, so all rain is likely for the entire northern Middle Atlantic on Thursday. With an approaching trough and clouds, highs will likely be in the 40s regionwide to perhaps 50F near Washington DC. Total QPF will likely range from less than .25in near KMDT to about .5in near KPHI.
The 1000mb surface low will pull off to the northeast by Friday with the trough axis approaching Pennsylvania from the west. 1000-500mb thicknesses will drop into the sub 525dm range as far south as Harrisburg. A very steep trough will settle into the region with a sharp north-northwest flow. H85 heights will drop to near -7C for the northern Middle Atlantic. Surface highs will be particularily well below normal especially towards Saturday. A few lake effect snow showers are likely Friday towards northwest Pennsylvania. See more details below. On Saturday, an upper level low passes through the trough axis over the northeast enhancing a few snow showers. Currently GFS/ECMWF correlated QPF fields show 0.01-0.03in QPF over much of the Northeast. This may signal rain/snow showers over much of the Northeast. Current MREF indicate high temperatures below 40F for the western 2/3rds of Pennsylvania and western Maryland with mid 40s elsewhere. With dewpoints in the low to mid 20s regionwide and temperatures aloft well below 0C, the first snow flakes of the region may occur for many areas Friday night into the first half of Saturday. A flurry or two may even be possible for those immediate areas east of the Appalachians. By Sunday temperatures begin to warm up back to seasonal values with sunshine.
(Courtesy of Penn State Meteo.)
"Current Water Vapor Loop"
(Courtesy of Penn State Meteo.)
"Fall Foliage Outlook" (Updated 10/23)
It is amazing how quick the fall foliage season ended. In fact if you slept through one day, you probably missed the peak. Very dry conditions in August for the northern Middle Atlantic promoted dull colors including browns and dull yellows. This was well forecast months ago, that this fall foliage season would not be the best. Maples still seemed to fair pretty well with brilliant reds and nice oranges, even in the maple forests of northern Pennsylvania above 1900ft. By the oaks suffered greatly regionwide with predominate browns. Past peak conditions have gotten about as far south as the Mason-Dixon line excluding western Maryland. I was up in the Kittatinny Ridge region north of Reading, PA and leaves were completely down above 1200ft. In fact it looked late November with brown conditions and an overcast strato-cumulus sky from the northwest flow. Colors right now are peaking towards southern Maryland and Delaware and towards the immediate Philadelphia suburbs/city center. A few important notes though... Peak conditions were actually quite a bit ahead of schedule in comparison to the last few Falls. In fact I was taking a look at foliage pictures from 2007, and peak conditions did not occur that year until around November 11-18 for the Harrisburg area and even later farther south. But most of that was courtesy to the unusually warm October that year with 80s much of the month including many record highs. I believe it went down as the warmest October on record. Last Fall colors were about a week later than this year. Very often I hear people argue that the weather does not affect Fall leave patterns and it is just the sun angle. This arguement just does not have much support. Every year the peak conditions vary with no pattern from year to year. It is highly dependent on temperatures and soil moisture. Still though, surprisingly, Fall foliage is understood very poorly in the sciences.
Fall Foliage Reports... Link
"Average Date of First Freeze"
(Courtesy of NOAA)
"Lake Effect Snow Conditions" (Updated 11/02)
I am excited. This is the first lake effect snow discussion of the season and signals winter's approach. While here I live in the downsloping capital of the world, my favorite type of weather is still lake effect snow. Anyways the first snow flakes of the region may fall for many locations. A weak sub 1000mb nor'easter will be pulling to the northeast by Friday afternoon resuming a strong northwest flow. A -1SD trough will sink in over the region with surface temperature anomalies around 10-15F below normal. A slightly tight pressure gradient will promote a breezy north-northwest flow with boundary layer gusts around 25mph. Warm lake temperatures in the 50s with surface temperatures in the 30s will promote a highly unstable atmosphere. Shearing winds aloft will CAP off any intense bands, but there still will be some light accumulations. Above freezing ground temperatures Friday and marginal mid to upper 30F boundary layer temperatures will only allow for a mix of rain and snow showers for the snow belts. The flow will be around 330F, which promotes banding into the Laurel Highlands. No accumulation is likely Friday and rain/snow showers will be confined to typical snow belts. But Friday night into Saturday morning, 700mb RH values will increase as an upper level low moves north of the area. This will enhance instability convective cells and orographically enhanced precipitation over the region. GFS/NAM/ECMWF QPF fields indicate a few sprinkles/flurries as far east as the Lower Susquehanna Valley. GFS/NAM show a weak Huron-Erie streamer into the southern Laurel Highlands and northwestern Maryland with light 1-2in snowfall accumulations possible above 2200ft Friday night. Also light coating-1in snowfall amounts are possible in all snow belt regions that Friday night. More widespread non-accumulating snow showers will be likely Saturday. Highs Saturday will be in the 30s for much of Pennsylvania and western Maryland with low to mid 40s for the lower elevations. I would not be surprised to see a 2.5-3in total towards Laurel Summit and Mount Davis in Pennsylvania or around McHenry, MD by early Saturday morning. Drying air will move overhead with an advancing anti-cyclone by late Saturday afternoon. Temperatures will warm back to normal values with sunshine by Saturday. For those with interests in the snow belt regions Friday night, stay tuned for rapidly changing conditions for the first light snow of the year. I would also not rule out a coating of snow for Pittsburgh and Erie overnight. Outside the forecast zone, orographic snows are likely for northern New York, northern Vermont, and northern New Hampshire in this period. Accumulations up to 5in or a bit more especially towards Mount Mansfield and similar favored peaks.
"Current Great Lakes Water Temperatures"
(Courtesy of NOAA)
"Long Term Outlook" (Updated 11/02)
The long term pattern will be dominated by rising heights over the eastern seaboard. The NAO is on the rise along with the EPO as they entire the positive range. This will allow the cool air to reload a bit into Canada and help to build a snowpack up for the northern parts of North America. The week of November 8-15 will likely be at or above normal with highs maxing out in the mid 60s during the height over the northern Middle Atlantic. The GFS and ECMWF have both been advertising this warmth in that time frame and wavelengths are in full support. What remains interesting is the wavelength period by the third week of November. The NAO looks to head slightly negative again and the EPO will definitely nose dive. At the time it appears arctic air will be diving into the western Plains. In fact a few 384hr GFS runs show near -20C H85 thermals into Montana. Eventually this cold air will slide eastward, but will be a bit modified as the core of the cold air moves more south than east. The cold air will eventually move in towards the east coast as November probably ends on a cold note. For those looking for their first synoptic snow, it is not likely through at least November 12 for most areas outside the higher elevations of New England. Patience is key in this pattern. It is nice to see though a pattern defying the typical La Nina structure especially considering the strength or anomaly of the equitorial Pacific SST deviations. MJO phase wavelengths support the colder air through early December over the east coast. I still believe much of the Middle Atlantic will receive a synoptic snow before the month's end excluding maybe the coastal regions. But for now this snow chance is a good two weeks away at least...
"Current NAO and PNA Predictions"
(Courtesy of NOAA)
"Anchorage, Alaska Tower Cam"
*Back due to popular demand!
"Monthly Temperature/Precipitation Outlook"(November)(Updated 10/23)
I think I am going to trend a bit on the mild side for the upcoming November despite interesting teleconnections. Mean 500mb guidance from the past week show a bit a southeast ridge beginning to flex its muscle into the southern Middle Atlantic. Latest 10/23/10 0utc GFS 10-14day 500mb mean actually supports this continuing in that range with a 588dm ridge over the southeast. Right now the polar vortex is just north of Alaska by about 200mi, which is good for now. But guidance suggests this may sink southward towards November. This tends to favor ridging over the east coast and troughing over the western United States up through Alaska and the Canadian Rockies. But current ensemble runs indicate a negative NAO to open up November. There will likely be an eastern cool pattern during the first week of November. The La Nina continues to show that it is already one of the strongest La Ninas on record. But it is encouraging to see little temeperature drops in Nina 3.4 SSTs. For those looking for an early season snowstorm this year, a few encouraging signs can be found in the cryosphere. Levels are at around normal values, which are actually higher than the previous few years. Siberian snow cover has shown impressive gains in the last two weeks and has reached above normal levels. Also North America snow levels have increased in northern Canada and Alaska courtesy of the trough moving through and associated low presssure system. None the less, I believe typical La Nina conditions will dominate November's weather with a southeast ridge. But cooler weather may return towards the end of the month with perhaps the first inland snowfall in this time period around or just after Thanksgiving. We shall see how those wavelengths turn out. Precipitation chances are right around normal for all areas. The farther south one goes in the Middle Atlantic will dictate how anomalous the warmth is this month as weak troughing from the negative NAO may be enough to save some areas in Pennsylvania from the warmth.
"Temperature and Precipitation Outlooks from Climate Prediction Center for next 30 days"
(Courtesy of NOAA)
-Winter Outlook 2010-2011...Link.
"Here northeast of Harrisburg 2010-2011 winter statistics"
Current Snow Cover- 0in
Monthly Total (November)- 0in
Seasonal Total- 0in
Winter Weather Advisories- 0
Winter Storm Warnings- 0
Ice Storm Warnings- 0
Blizzard Warnings- 0
Freezing Rain Advisories- 0
Winter Storm Watches- 0
Lowest High Temperature- 49.7F
Lowest Low Temperature- 24.9F
Wind Chill Advisories- 0
Wind Chill Warnings- 0
(Snow Storms Stats)
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|Dew Point:||15.2 °F|
|Wind Gust:||9.0 mph|
Updated: 10:37 AM EST on January 18, 2014