Ph.D. Student - Earth System Science (UC Irvine), B.Sc. - Atmospheric Sciences (Cornell University)
By: Zachary Labe , 08:50 PM GMT die 02o November, anno 2008
"Afternoon Thoughts" (Updated 11/2)
So happy November, and we are less than a month away from the meteorological start to winter. It seems so hard to believe that in about two weeks we will most likely be looking at snow chances almost every week for some part of the Northeast. But today I want to talk a bit about a little rant of mine on official weather reporting sites and their records. KMDT, Middletown, which is just south of Harrisburg PA is my official weather reporting site in my region. The elevation of the weather site is 303ft, but the elevation of my location is 508ft and due north-northeast of Middletown. What bothers me is the reporting information. Temperatures are always higher at Middletown, especially during the night with sometimes a temperature spread of up to 10degrees during radiational cooling nights. And I am not the only one who is colder, almost all the personal weather stations around the region are always colder, even locations within a 5mile radius of Middletown. And then during precipitation events they always record the lowest precipitation totals around the region, and not just during thunderstorms, but also during stratiform rain events where almost everyone sees the same amount of rain. Our local weatherman on the news has to find ways to make excuses for the strange precipitation amounts that Middletown reports. And then during snowstorms the usually measure a good 1-3inches less than I do and almost all locations around the region. Now yes temperatures and precipitation totals do vary around the region, but this occurs ever single time and occurs all across the United States. Many official NOAA climatology stations are found in cities and are located in the urban heat island effect regions. And then there are a few stations outside the city in rural areas such as in Johnstown and Thomasville (York) where temperatures are nearly 5degrees lower than surrounding areas. So then this raises the question that are temperatures really warming all over the United States, or is it just in the cities. We all know the Urban Heat Island effect is a reality, it only takes a short drive on a clear night from the city to the valleys to notice the temperature spread. Then are really these dramatic shifts in temperature readings for little snowfall and warm temperatures really this extreme. Take last winter for example my snowfall total was nearly 27inches of snow, but yet at Middletown it was reported 14inches. Similar COOP reporters had snowfall totals similar to mine across the region. I use accurate techniques to measure snowfall along with averaging in the melted snow then multiplying it using the average ratio reported from rain to snow. Same with my temperatures, I recorded a low of 4degrees during March last winter, which would have tied the coldest March low temperature ever, yet Middletown reported 8degrees, breaking no records. My weather station is a Davis Vantage Pro2 along with the latest 12hr fan aspirated temperature fan. So accuracy is +-.1degree. Yet I am not in a rural location, I am in the suburbs, so I am sure locations on the other side of Blue Mountain were even colder. So why does NOAA not position their weather stations in mean temperature locations in the suburbs instead of placing them near cities and airports? Are temperatures really warming as much as weather stations indicate or is the Urban Heat Island effect causing these temperature extremes each year? The amount of rural land across the world is much higher than city land, so maybe city locations are seeing the warming every year. In any case every year, especially in winter, it bothers me to see the official records from reporting stations across the United States as most of them are obviously warmer than a majority of the region and report less snowfall. Middletown is one of the worst stations in the state and often reports temperatures the same as Philadelphia for the lows yet Middletown is farther away from the bay, ocean, farther northwest, and near the Appalachians. I guess that is one reason I keep track of daily weather records each day throughout the entire year. In any case for those of you who have personal weather stations, I highly recommend those accuracies than your locale official reporting station.
"Current Surface Plot"
(Courtesy of HPC)
(Courtesy of Wunderground)
(Courtesy of NOAA)
"Forecast Discussion" (Updated 11/2)
A pretty quiet weather week is ahead, but a few minor nuisances could cause a slightly tough forecast for southeastern Pennsylvania. The backdoor cold front lifts northeastward out of the Northeast for Monday giving way to a move southerly flow. The 1038mb high pressure will lift northeastward across the Canadian Maritimes. Meanwhile a very amplified ridge over the mid section of the nation will move eastward. A shortwave rotating along the northern peripheral of the ridge will move across western Pennsylvania during Monday. Rain showers will be confined to far northwestern Pennsylvania with QPF generally less than .1inches. An easterly flow will develop in eastern Pennsylvania keeping cool maritime air over the southeastern ridge along with upsloping stratus. No precipitation is expected other than clouds and cool temperatures. Across central Pennsylvania sunshine will prevail with H85s near +5C. Meanwhile a disturbance off the coast of North Carolina will organize during Tuesday and very slowly move northward along the Middle Atlantic Coastline keeping a marine air mass over eastern Pennsylvania, while sunshine prevails across the west. 850s will rise to nearly 10C across western Pennsylvania with boundary layers highs well above normal, but eastern Pennsylvania should see near normal temperatures as clouds keep a hold on temperatures. Precipitation will develop to the northwest of the center of circulation with the coastal low and move inland late Tuesday and Wednesday with some .1-.25 QPF across southeastern Pennsylvania. This coastal low will stay generally weak with pressure around 1008mb. But it will keep an easterly flow all week over southern Pennsylvania and eastern Pennsylvania. Western Pennsylvania though will see above normal temperature in the 60s and maybe 70degrees a day or two in the metropolitan region of Pittsburgh. By late in the week a cold front approaches from the west with some light QPF. H85s stay near 10C across western Pennsylvania and lower values in the eastern and central part of the state. So for most of the week it will be quiet with sunshine over the west and very mild temperatures, but cool and damp conditions over the eastern part of the state.
(Courtesy of Penn State Meteo.)
"Current Water Vapor Loop"
(Courtesy of Penn State Meteo.)
"Weekly Forecasts" (Updated 11/2)
Monday- Easterly flow will dominate eastern Pennsylvania as high pressure off the coast keeps high level moisture funneling in from the east resulting in clouds to about as far west as State College. Over western Pennsylvania a shortwave will result in partly to mostly cloudy skies with some light rain showers up towards Erie. Rainfall should be generally less than a tenth of an inch. Across northern and central Pennsylvania sunshine will prevail with mild temperatures. Highs will vary greatly over the state with highs in the 50s over eastern Pennsylvania, highs in the low 60s in the western part of the state, and highs in the mid 60s in areas that see sunshine in the north and central part of the state. For Monday night easterly winds will keep the southeast socked in clouds with mild lows in the 40s, elsewhere radiational cooling should result in lows in the upper 30s with clear skies. Some late night fog may form in the east along with low stratus particularly the closer you are to the bay. Ceilings may fall as low as 500ft with IFR conditions.
Tuesday- Sunshine will persist west of the Chambersburg-State College-Williamsport line with very mild temperatures. Meanwhile an offshore coastal low keeps an easterly flow with a marine air mass. Cloud over will be widespread over the east with drizzle at times. Precipitation amounts will not be greater than .05inches. Highs will vary greatly with areas that see cloud cover and areas that do not. Highs will be in the mid to upper 60s for western, central, and northern Pennsylvania. While highs in the south-central region to the southeast region will see highs in the upper 50s which are right around normal. Ceilings will be very low across the southeast towards evening lowering to near 800ft close to Philadelphia. Rain showers will overspread the southern and eastern part of the state with some moderate intensity with rainfall amounts up to .25inches in some areas. Lows will be mild in the southeast generally in the upper 40s with lows in the mid to upper 30s elsewhere across the state under radiational cooling conditions.
Wednesday- Rain showers will be across the eastern part of the state for Wednesday with low clouds and MVFR conditions. Rainfall amounts should on average be less than .25inches with highest amounts near Philadelphia. Some morning fog cannot be ruled out. Sunshine will be over the rest of the state with high temperatures nearly 15degrees above normal in the mid to upper 60s. Highs in the east will be in the upper 50s near to slightly below normal. Towards night the rain should generally turn to drizzle with some patchy fog over the east. Lows will be in the mid 40s in the south and east with lows elsewhere in the mid to upper 30s under great radiational cooling conditions. Some breezy winds may occur near Philadelphia as the coastal storm pulls away Wednesday night.
Thursday- Finally eastern Pennsylvania may break out of the easterly flow and see some sunshine and feel the warmer temperatures. Still though going to go a little pessimistic for now with partly to mostly cloudy skies over the east and partly cloudy skies over the western part of the state. Sunshine should boost highs well above normal statewide with highs in the 60s to even upper 60s in a few areas. Winds will turn southerly later in the day moving more dry air into the region. Thursday night should be a mild night statewide with partly cloudy skies over the west with high cirrus ahead of next front; over the east skies should be clear. Lows will generally be in the 40s with a few upper 30s in the north.
Friday- Cold front will be approaching from the west with thin high cirrus over much of Pennsylvania during the day with rain showers approaching the region by afternoon. Some rain showers may occur in the afternoon over western Pennsylvania with precipitation totals up to .25inches. Highs will be slightly cooler than past days over western Pennsylvania with highs in the lower 60s and mid 60s over the east. Friday night we will see lows mild in the 40s statewide with rain showers statewide. Rainfall amounts generally up to .25inches statewide. Eastern Pennsylvania will see the least amount of rainfall. Colder air will push into the state late at night for the weekend.
Saturday- Colder air will be felt over much of the state with instability lake effect rain showers and snow showers over the mountains. No snow accumulations are anticipated. Downsloping winds will keep partly cloudy skies over the central and eastern part of the state. Highs will be near 5-10degrees below normal with highs in the upper 40s over the central part of the state and western valleys, 50s over the east, and upper 30s in the north and western mountains. Saturday night snow showers will be across the north and west with a coating of snow possible on the highest ridges. Lows will be cold in the low 30s across the mountains and mid to upper 30s elsewhere.
"Current River Ice Reports and Ski Conditions" (Updated 11/2)
As we all know there are no ice reports to be reported and all ski resorts have yet to open in Pennsylvania, but we are starting to get close to that opening time period especially towards to end of November. Taking a look at water temperatures, they are really dropping in area lakes, streams, and rivers. Lake Erie has reported some substantial temperature drops after the recent cold outbreak with water temperatures in the shallow parts along the northern coastline in the extreme low 50s with mid 50s elsewhere. Still though this is plenty warm enough to develop some pretty intense instability when lake effect snow outbreaks occur. Also during cold nights, hypothermia can still occur, as temperatures are pretty low in some lake beds and river beds, so take precaution when doing some late night fishing or boating. As for fishing, local summer fish such as panfish, bass, pike, etc. are quieting down, but still fishing for trout, walleye, muskees is still pretty good around the state. Some local lakes have even recently stocked a session of Fall trout. I was up at Little Buffalo State Park where they recent stocked some trout; they were jumping around at mayflies, but were not interested in any other bait. So I would recommend fly-fishing for the trout this time of year. Here are a few Pennsylvania ski resorts and their local opening times…
Ski Sawmill… 12/08
Ski Liberty… 12/05
Shawnee Mountain Ski Area… 11/29
Camelback Ski Area… 12/05
-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 11/2)
No lake effect snow worries for this week and very few maritime concerns this week with low wind speeds and waves. So I want to summarize the recent lake effect snow outbreak last week, which was not really talked about much because of the coastal storm and record snow amounts in northeastern Pennsylvania. I was extremely impressed by the setup we had with the recent lake effect snow outbreak. At first it took a while for the lake effect machine to get going on Monday as most of the moisture was taken to the coastal storm. A few strong little bands developed in far northwestern Pennsylvania in Erie County with mostly thunder sleet and little snow. Through Monday night the flow became a little more favorable with some light snow/sleet showers in southwestern Pennsylvania, but most of that activity was confined in Garret County, Maryland. As the coastal storm pulled up through the Hudson River Valley the flow turned northwesterly creating a few strong lake effect snow bands on Tuesday in parts of western Pennsylvania. But from the Bedford-Altoona-Philipsburg-Bradford line it seemed no snow showers wanted to make it east of there. Snow advisories and winter storm warnings were then issued for northwestern Pennsylvania and the Laurel Highlands. Snow accumulations began to occur as boundary layer temperatures dropped during late Tuesday afternoon and the flow turned more west-northwesterly turning lake effect showers across all of Pennsylvania as far south as Lancaster. Snow accumulations were really beginning to be reported with some very impressive bands forming. By early evening a very strong Huron-Erie streamer formed from northwestern Pennsylvania into State College and south along 322. During winter and with slightly colder temperatures this band would have been referred to as the classic 322 streamer that often carries snow accumulations as far south as Harrisburg, Pennsylvania. Snow accumulations ranged up to 8inches in parts of the Laurel Highlands near Mt. Davis and Laurel Summit. Also in the mountains of northwestern Pennsylvania in Warren County, significant snow accumulations occurred up to 9inches. Areas in the valleys even saw snow with .8inches of snow in Pittsburgh breaking a daily record snowfall for that day in October. The first flakes of the season occurred in most all other locations across the state along with an additional C-1inch of snow in northeastern Pennsylvania in Susquehanna and Wayne Counties where already over a foot of snow had already occurred from the coastal storm. All in all this was a very impressive lake effect snow event more similar to an early December Outbreak. It does not appear I will be talking about lake effect snow forecasts for about two weeks until we get into mid November when the pattern looks a bit more colder.
"Current Lake Erie Wind Direction and Speed"
(Courtesy of NOAA)
"Current Lake Erie Water Temperature"
(Courtesy of NOAA)
"Long Term Outlook" (Updated 11/2)
A very interesting long-term pattern is setting up for mid month. Teleconnections are favoring a very amplified jet stream with a deep east coast trough and ridge in the west. The AO has been highly positive since about early October. This has been causing below normal temperatures over the Arctic, and this is evident with the dramatic buildup of sea ice. Snow cover has also been building up in northern Canada. Meanwhile over Greenland a ridge has been over that region with above normal temperatures. A dramatic shift in the polar air will occur come mid month with AO heading negative near –2 with some ensembles even as low as –4. This will cause high pressure over Greenland with a trough over that region and a more ridge over the arctic. The cold Siberian air will head southeast towards the United States in the Midwest and Northeast. Meanwhile closer to home teleconnections will favor east coast troughing with a marginal negative NAO and a marginal positive PNA. Current GFS ensembles forecast the switch around the 9th of the month, while the operational GFS delays the switch until more midmonth. EURO weeklies are generally in support of GEFS. I am leaning towards a very mild start to the month with a gradual cool down this coming weekend. Then I think the real cold air penetrates in time for around the 16th of the month. So it should be an interesting long term and this will really show how potentially the pattern of how the first half of winter will shape up. I still am liking my winter outlook with a very cold December and gradually warming months thereafter.
"Current NAO and PNA Predictions"
(Courtesy of NOAA)
"Monthly Outlook" (November)
So hard to believe October has already passed, but it has and we are now entering November. Looking at my October outlook I called for normal to slightly below normal temperatures with normal precipitation. Looking at most official climate stations most areas came in with below normal temperatures around 1-2degrees below normal. I am very pleased with my temperature forecast, but as for precipitation almost all areas were below normal in precipitation and many areas did not see rain until the last few weeks in the month. It seems the Fall season has been pretty dry in consideration to normal. Snowfall was highly above normal in all locations with snowfall totals over a foot in parts of the Poconos and areas in western Pennsylvania saw record monthly snow totals including Pittsburgh which I believe saw the 8th snowiest October on record. Looking at now November there are some better signals for the temperature and precipitation totals than there were last month. Last month there were few signals for the overall pattern.
Temperature- Temperatures look to be near normal across much of Pennsylvania, except southern Pennsylvania which should see below normal temperatures. Across other parts of Pennsylvania I cannot rule out some slightly below normal reports. It seems that the first half of the month will favor above normal temperatures, but clouds from marine layers in an easterly flow will keep temperatures closer to normal in the south. The positive temperature departure should be much higher in the north and west than in the south and east come mid month. By midmonth teleconnective signals are showing a dive-bombing AO along with a positive PNA and a negative NAO. I am thinking the second half of the month will be very cold and that pattern should continue through December. Looking like some nice Greenland Blocking will develop. EURO weeklies and GEFS indicate this pattern switch come midmonth, but the operational GFS is a bit slower to show this pattern change. So overall looking at normal to below normal temperatures statewide.
Precipitation- I think precipitation will be near normal. I am looking at a more active storm track than recent months, but still not anomalous in comparison to normal. Coastal storms look possible along with warm air advection events especially near the pattern switch come midmonth. Snowfall looks to be near normal with almost all areas likely seeing their first accumulating snow before the month’s end. Lake effect snows look possible along with some nuisance clipper type events. Looks like snowfall will be in quite a positive start in comparison to normal for parts of eastern and western Pennsylvania as we head into the start of winter.
"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- 0.00inches
Seasonal Total- Trace
Winter Storm Warnings- 0
Heavy Snow Warnings- 0
Blizzard Warnings- 0
Lowest Temperature- 26
Wind Chill Advisories- 0
Wind Chill Warnings- 0
(Snow Storms Stats)
First Snow - October 29 - Trace
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