Ph.D. Student - Earth System Science (UC Irvine), B.Sc. - Atmospheric Sciences (Cornell University)
By: Zachary Labe , 8:55 PM GMT on October 25, 2009
"Afternoon Thoughts"(Updated 10/25)
Good afternoon all!!! Sorry for the delay in the new blog, but it was a hectic week. By the way my winter weekly weather format blog will debut next weekend as we start November 1. Anyways so this weekend I headed out to the grocery store as most all of us do during our free time on the week, but low and behold the holiday decorations were out. "Let it Snow" was playing with Santa Claus hoisted on a sleigh next to the cereal. I thought my goodness people are still buying Halloween candy. It seems every year local retailers push the limit earlier and earlier for the start of the holiday shopping season. While it makes sense local businesses want to take advantage of the extra gross income during that time of year, but there comes a point to where the consumer is almost offended. I even remember seeing Christmas decorations out in the beginning of October displayed next to skeletons, witches, and ghosts. Soon Valentine's decorations will be illuminating store windows, lol. December just does not seem the same anymore, perhaps it is the lack of snow courtesy of global warming (just kidding), or maybe the political garbage of "Happy Holidays", or again maybe it is just the idea that the shopping season is so extended despite the poor economy. When I think of December, which is my favorite month of the year, I think of cozy fires on a clear cold night and holiday lights illuminating the countryside. Now I know I am sort of contradicting myself, because I am talking about Christmas here in October; but this is just one of my rants I had after I went into that store. As a society, myself included, we are always trying to push the limits and always desiring what is to come in the future. In September we longed for Halloween, at Halloween we long for Christmas, in December we long for Spring, in March we long for Summer, then in July we long for snow all over again. It is just part of this vicious cycle. So here again I am pushing the limits in this mix-match of thoughts/rants above. Just a reminder, only 61 days as of October 25 left in the holiday shopping season, hahaha.
(Courtesy of NOAA)
"Current Weather Map"
(Courtesy of Wunderground)
"7-Day Forecast Discussion"(Pennsylvania, Maryland, Delaware)(Updated 10/25)
A 1024mb high pressure remains in control with a zonal flow over the eastern portion of the United States with clear sky across the entire Middle Atlantic. H85s around 7-8C are promoting temperatures a few degrees on either side of normal. High pressure coupled with low dewpoints in the upper 30s will promote an ideal radiational cooling night as winds decouple. Lows will be several degrees below normal with lows in the upper 20s over northern Pennsylvania particularly towards Bradford through Wellsboro. Lows in the low 30s are likely for a majority of Pennsylvania and western Maryland. For southern portions of Pennsylvania south of the Pennsylvania turnpike and east of the Harrisburg-York line, lows will be in the mid 30s to upper 30s near Philadelphia. Lows in the low 40s are likely for much of Delaware and Maryland including coastal areas. Frost and freeze conditions are likely towards morning for western Maryland and most all areas along and north of the Pennsylvania turnpike. Patchy fog is also possible Monday morning especially towards Williamsport where air and water temperature contrasts are near 25degrees which may promote patchy fog formation. Elsewhere just light 3-4mile ground fog is likely. The 1028mb anticyclone continues to dominate the weather for Monday with sunshine across all of the Middle Atlantic. H85s near 7C will promote near normal temperatures for Monday with highs in the 60s for most areas and upper 50s for northern Pennsylvania. Towards Monday night a few upper and mid level clouds will begin to stream over the region as increasing moisture aloft filters in ahead of the next complex storm system. A 1004mb strengthening low will move up through the Mississippi and Ohio River Valleys allowing for moisture to advance northward east of the center of circulation. H85s will rise to near 10C as a warm front lifts over the region towards Tuesday. But first, Monday night will feature some radiational cooling conditions before the cirrus moves overhead with lows ranging for northern Pennsylvania in the lower 30s to upper 30s over southern Pennsylvania and 40s across Maryland and Delaware. Lows will likely be reached around 2-3am and slowly rise or stay steady through daybreak. As the warm front lifts over the region, the 1024mb high pressure will lift northeastward but still be close enough to the region for some cold air damming initially especially along and north of the Blue Ridge Mountains. Weak frontogenesis and rising PWATs near 1-1.3inches will allow for moderate rain to form over much of the east coast with a widespread rainfall. Latest guidance suggests a decent half inch of rain for all areas during the day Tuesday. Highs will vary over the region with upper 50s over eastern and central Pennsylvania courtesy of the cold air damming influence to mid 60s over western Pennsylvania and all of Maryland/Delaware. These highs will still though be near normal just a tad on either side of normal. A developing baroclinic zone offshore will allow a weak transfer of energy to a very weak 1010mb surface low near the Delmarva. The only influence of this low will be the influx of moisture off the Atlantic into the Middle Atlantic. Tuesday night features the heaviest rainfall with a moderate stratiform rain shield over the region. Low stratus will promote ceilings as low as 500ft with IFR conditions at most terminals. At times of heavier rain conditions will deteriorate to LIFR conditions. Lows will be mild and generally in the 50s to low 60s for most locations. Areas towards extreme southwestern Pennsylvania and southern Maryland may even see non-diurnal temperature rises overnight.
Towards Wednesday left-over rain showers will be over the region as the anti-cyclone over Newfoundland, Canada will continue to allow for the slow northward progression of this low pressure. Total QPF for this event will likely range from 1-1.25inches for most areas. This wet pattern will push monthly rainfall totals near 6inches for much of Pennsylvania and northern Maryland. H85s will rise to near +12C with ridging aloft, but cloud cover should prevent temperature rising to high. High temperatures will likely range from low 70s over southern Maryland and extreme southern Delaware to upper 60s over areas along the Mason-Dixon Line. Highs in the mid to upper 60s are likely for much of Pennsylvania with low 60s for elevations above 2500ft. Wednesday night will allow for conditions slowly to clear out of the region with stratus slowly rising throughout the night. Lack of cooler air behind the front will maintain temperatures near normal with lows ranging from the low 50s over southern Maryland to low 40s over the north central Pennsylvania Mountains. A few areas of fog may also form overnight with visibilities dropping to near 1-2mi or less for any areas that can clear out. The highest chance of this is over western Pennsylvania near Pittsburgh up through Erie and Bradford. 1024mb high pressure moves in for Thursday allowing for sunshine over the region. Temperatures will remain near normal for highs with ranges from mid 60s over southern Maryland to low 60s near the Mason-Dixon Line to upper 50s over northern Pennsylvania. Many locales are holding trick-or-treat Thursday night at least here in southern Pennsylvania; at first glance it looks like skies will be partly cloudy with lows dropping into the 40s for most locations with 30s along and north of the interstate 80 corridor. Things turn a bit more uncertain towards the weekend. For now it looks like Friday will feature partly cloudy skies over the Middle Atlantic with slightly above normal temperatures in the mid to upper 60s over the region. A few mid to upper level cirrus will stream in throughout the day with spotty orographic aided cumulus over the higher elevations. Clouds will increase towards evening ahead of the next front, but timing remains uncertain. A deep trough will develop over the western United States with well below normal temperatures and perhaps a northern plains snowstorm. But the eastern extent of the cold air will eventually weaken as the front washes out towards the weekend as it moves across the east coast. Despite this a small frontal band of rain is likely towards Saturday or Saturday night with increasing northwest winds, cooler and drier air for Sunday. Temperatures may get pretty warm on Saturday, Halloween, as H85s rise +1-2deviations above normal.
(Courtesy of Wunderground)
(Courtesy of Penn State Meteo.)
"Lower Susquehanna Valley Forecast"(Franklin, Adams, York, Lancaster, Cumberland, Perry, Dauphin, Lebanon Counties)(Updated 10/25)
High pressure remains in control through Monday night creating pleasant fall conditions over the entire Lower Susquehanna Valley. After some initial cirrus moves eastward away from the region Sunday evening, winds will decouple combined with low dewpoints producing ideal radiational cooling conditions. With dewpoints in the upper 30s, temperatures will quickly fall throughout the night to low 30s over favored cooler locales such as Fishing Creek Valley, Clarks Valley, Powell’s Valley, Stony Creek Valley in Dauphin County, also valleys in northern Franklin County such as Amberson Valley. Locations along South Mountain and Blue Mountain may also see low 30s. Elsewhere mid to upper 30s are possible. Frost is possible over areas especially along and north of the turnpike where dewpoints will be a tad lower. Patchy fog is also possible Monday morning especially in northern Dauphin and Perry Counties along the Susquehanna River where there remains a sharp water/air temperature gradient. Watch out along the Clarks Ferry Bridge along 22/322 Monday morning for fog with visibilities below 1mi. Elsewhere patchy radiation/ground fog is possible with visibilities generally around 2-3mi. Monday will feature sunshine prevailing over the entire Lower Susquehanna Valley as high pressure remains in control, but will slowly be pulling out of the region towards the Canadian Maritimes. Highs will be near normal over the region with low 60s likely with a few mid 60 readings especially in downtown Harrisburg, York, and Lancaster. Monday night will feature more radiational cooling conditions with low dewpoints, generally clear skies, and calm winds. Lows will drop to numbers a few degrees warmer than Sunday night with lows ranging from the mid 30s in the colder valleys to upper 30s for areas south of the Pennsylvania turnpike. Patchy frost is possible towards rural areas north of the Pennsylvania turnpike particularly in northern Dauphin County to all of Perry County. A few cirrus clouds may approach the region overnight allowing for temperatures to take a bit of a rise towards daybreak with lows likely reached around 3-4am. Tuesday will feature increasing clouds in the morning ahead of a low pressure in the Midwest. An easterly flow will allow for weak cold air damming from the high pressure to the northeast keeping highs in the 50s throughout the day with a few low 60 readings over southeastern Lancaster County. These highs will be slightly below normal. Rain showers will advance from the southwest to the northeast during the afternoon hours likely affecting the southwestern portions of the Lower Susquehanna Valley in Adams, Franklin, and York Counties by a little after noon. By late afternoon rain showers will be widespread with a lowering stratus deck with ceilings near 900-1000ft. Rainfall totals for Tuesday will likely be around .1-.25inches over the valley. Tuesday night will feature the heaviest rain as the storm system allows more moisture to advance into the region with the warm front continuing to lift northward into southern New York State. Rain may be heavy at times as moisture continues to pool aloft from the anomalous easterly flow as a weak surface low forms near the Delmarva and quickly scoots northeastward. Total rainfall overnight may be near .75inches. Ceilings will continue to lower throughout the night with them reaching as low as 500ft with IFR conditions. Lows overnight will be mild in the 50s across the entire Lower Susquehanna Valley with upper 40s possible for elevations above 1650ft.
Wednesday will feature morning low stratus and spotty rain showers. The storm system will progress northeastward through southern Canada allowing for a clearing line to approach the Lower Susquehanna Valley likely during the latter half of Wednesday. Highs will be slightly above normal as the warm air will finally overcome the cold air damming. Highs will be in the mid to upper 60s with a few 70degree readings possible along the Mason-Dixon Line in extreme southern Lancaster, York, and Adams Counties. Clearing skies will prevail from west to east overnight Wednesday as an advancing high pressure over the Tennessee Valley moves towards south-central Pennsylvania. Lows will be near normal in the lower 40s over the entire Lower Susquehanna Valley. Urbanized areas will likely see mid 40s including York, Lancaster, Harrisburg, and Middletown. Thursday will feature partly cloudy skies over the region with patchy morning fog. Highs will be near normal in the lower 60s over the entire region. For many local townships, boroughs Trick-or-Treat is Thursday night in the Lower Susquehanna Valley; and at this time it looks like skies will generally be clear with temperatures falling into the low to mid 40s over the valley. A few upper 30s are possible towards upper Dauphin County near Lykens and Williamstown. Towards Friday high thin clouds will stream overhead as a strong, but weakening front pushes through the Mississippi Valley. But despite this, sunshine will generally prevail with slightly above normal temperatures in the mid to upper 60s over the region. The southwesterly flow will aid in these mild temperatures. Towards Friday night a bit thicker cirrus deck moves overhead promoting a mild night with lows in the upper 40s. For information on the weekend weather, look at the end of the regional discussion posted above.
"Current Lower Susquehanna Valley Radar"
(Courtesy of Wunderground)
"Chesapeake Bay and Atlantic Coast Marine and Boating Forecast"(Maryland and Delaware Coastal Forecast)(Updated 10/25)
High pressure dominates the weather through Monday night across local waterways including the Chesapeake Bay basin, Delaware Bay basin, and Atlantic coast along Maryland/Delaware. Wind remains a bit on the breezy side along the Atlantic Ocean coastline where a small craft advisory remains in effect through Sunday night with a chance of 6-8ft waves and winds near 25knots. Temperatures remain warm on Monday with sunshine and winds quite calm for the perfect Fall boating day. Towards Tuesday a cold front and low pressure over the Ohio Valley will be moving northeast allowing a southwest flow to sharpen over the region. Small Craft Advisory thresholds will likely reached for all local waterways with winds out of the southwest around 25-30knots. During the later part of the day Tuesday winds will shift more easterly allowing a marine layer to encompass the region. Rainfall is possible across coastal waterways towards Tuesday night as the storm system continues to approach the region. Poor boating conditions are likely through Wednesday night as high pressure to the north maintains a slow progression for this storm system. Guidance suggests a chance of heavy rain on Wednesday with an anomalous easterly flow and develop baroclinic zone off the coast where secondary low may form near the Delmarva and move northward. Towards Thursday a lull between storm systems is likely with some sunshine. The flow will shift out of the northwest and gust around 15knots maintaining conditions less than Small Craft Advisory Thresholds. It remains uncertain how quickly the low stratus dissipates towards Thursday, but with minimal inversion we should be able to see sun by later in the day along local waterways. Towards Friday weak high pressure remains in control for a decent boating day. Looking at the calendar this may be one of my last Chesapeake/Delaware/Atlantic waterway outlooks as I likely transition to my winter blog format next week for the start of November. Anyways by the weekend a very sharp cold front approaches the region and may pose some issues on the coastal areas for possible coastal flood statements and high winds before and after the frontal passage. Colder air moves in for the start of November under a northwest flow with downsloping conditions over the coastal areas. Happy Boating!!!
"Current Atlantic Coast Forecast Wave Heights and Chesapeake Bay Forecast Wind Direction/Speed"
(Courtesy of NOAA)
"Updates on Winter Predictions" (Updated 10/25)
For this update I am going to post my concerns for this upcoming winter. For the past few discussions I had been posting discussions on recent teleconnection updates and/or ENSO updates. But this time around I would like to post my concerns for this upcoming winter forecast, which I really have not mentioned. My biggest concern is the possibility of the trough axis being centered over the Midwest generally promoting an inland storm track. If this scenario would occur, the high negative temperature departures would be over the Midwest and especially the Northern Plains. But when I was going through analogs with a similar scenario to this; they were extremely difficult to find. The only winter that had a similar trough axis for a majority of the winter months was 1958-1959. In all other instances for moderate El Ninos there were not any other similar trough axis placements. Generally El Ninos promote an inland storm track into November and the first half of December which goes right along with forecast. So for those concerned about the recent weather pattern and the one that we will be facing going into November; I would not be too concerned. Rarely has a moderate El Nino not produced a decent winter across the Middle Atlantic. Another concern of mine is this disjunction of teleconnections, which is similar to what we are seeing now. Current teleconnections are all over the place with a negative NAO according to the CPC, but it really is not negative. It is just a cool pocket displacing a weak negative east-based NAO. Also the PNA and EPO are near neutral again not pointing to any signs of a significant weather pattern. Generally a zonal flow with an occasional deep trough over the west. If for some reason we are faced with an inland storm track this winter, it is likely due to the fact of the lingering effects of La Nina and the negative PDO despite indices which say it is positive. For now things look like they are going perfect according to my forecast issued back on Labor Day with a moderate El Nino looking to dominate the weather pattern.
Winter Outlook 2009-2010...Link
"Equatorial Pacific SST Anomalies"
(Courtesy of NOAA)
"Average Date of First Freeze"
(Courtesy of NOAA)
"Fall Foliage Outlook" (Updated 10/25)
Well it is hard to believe the end of October is already here with Halloween less than a week away. Basically another month before we enter winter, which is even harder to believe. Anyways looking across the northern Middle Atlantic many areas are at or past peak conditions. Across the northern counties in Pennsylvania and Garret County, Maryland fall colors have already peaked as many trees in this region are hardwoods and primarily maples. There is still some color along the Pine Creek Gorge from Wellsboro southward towards Jersey Shore/Lock Haven. Color is also reported around peak conditions near the lake shore in Erie County where slightly warmer lake temperatures have helped to prevent the coldest of air along the countryside within 25mi of the lake. But generally most trees have shed their leaves in this region with mountains quickly transitioning to brown with a touch of yellow from nearby oaks. Hard freezes gave way to the early Fall foliage season in this region. Also the heavy snow last weekend helped to drop most leaves that remained on trees in the interstate 80 corridor on northward. Across the central third of Pennsylvania including Butler-State College-Williamsport-Mt. Pocono conditions are at or past peak. Heavy snow resulting in moderate to heavy accumulations caused widespread destruction in Fall foliage creating a very short fall color season in this region. Many elevations above 2100ft have very little if any leaves remaining on the trees. The best color is being reported across the southern end of this region towards Selinsgrove in Northumberland County through the southern Poconos in southern Carbon and Monroe County. By the end of this week towards Saturday all areas will be past peak conditions. Across the southern third of Pennsylvania conditions vary from patchy to at peak conditions. Starting from west to east, Pittsburgh through the Laurel Highlands is reporting past peak conditions as recent winds and light snow have knocked most foliage off the mountainsides. Towards Mt. Davis and Laurel Summit, snowfall totals around 2inches helped to cause a widespread shade of brown on the mountains especially above 1800ft. Towards the southern ridge and valley region from Raystown Lake through Indiantown Gap along Blue Ridge conditions are at peak and are absolutely wonderful. South Mountain is also reporting peak colors with oaks even showing decent shades of yellows. Fall colors are reported by local foresters to be the best in years. I was comparing pictures from the warm October of 2007. In 2007, Blue Mountain peaked around the 10-15th of November. This year we are peaking from the 24-31st of October. Best viewing locations include the Appalachian train scaling Peters Mountain (1600ft elevation), Boyd’s Big Tree Conservation area scaling Blue Mountain (1250ft elevation) and along the northern side of Blue Mountain (600-800ft). Also a trip to Caledonia State Park, Kings Gap state Park, Memorial Lake State Park should produce wonderful picture opportunities along the scenic vistas facing the Dutch Country and the Blue Ridge Mountains. Across northern Dauphin County Joseph E. Iberson Conservation area and the Ned Smith Center will provide beautiful views of the countryside in that region along Peters and Berryburg Mountain. Towards York and Lancaster County colors will be approaching peak by the end of this week with areas along the Susquehanna River in Lancaster County producing beautiful views of the Dutch Country. The Lehigh Valley is reporting peak fall color conditions with wonderful viewing locations towards Hamburg near Hawk Mountain up through Ralph Stover State Park. Closer to Philadelphia conditions remain patchy but are progressing quite quickly. A trip near Valley Forge and towards the Brandywine Susquehanna River Museum should result in great pictures possibilities. Farther south towards the rest of Maryland excluding the far west, conditions remain a few steps above patchy with near peak conditions towards Hagerstown, Maryland through Frederick, Maryland. Antietam National Historic Area would provide great fall color viewing possibilities this week. Towards southern Maryland into Delaware conditions are near patchy with oaks showing little to no color change. Maples are showing brilliant reds and oranges along with ornamental trees. This week through next week is the final week for great Fall foliage conditions over the mountains of the northern Middle Atlantic. Take in the advantage of the great colors this year courtesy of the wet Summer and chilly Fall.
Fall Foliage Reports... Link
"Long Term Outlook" (7-14 Day Time Frame) (Updated 10/25)
The long term forecast is a bit more uncertain than typical. Lacking any strong indicators from the teleconnections and model confusion promotes forecast confusion. But I will make an attempt at my generalization for the weather pattern as we enter November. By the way my November outlook will be out next weekend. Anyways a weakening cold front will move towards the region for this upcoming weekend. This front will be responsible for nearly -20degree temperature departures over the western United States and northern plains. Highs even in Denver may struggle to reach 32 as the trough deepens over the region. The extent of this (-2)-(-3)deviation trough will weaken in its eastward extent only bringing marginally cool air towards the eastern Great Lakes and Northeast for the beginning of November. Remember November starts next Sunday. H85s will drop to around -2 over the Middle Atlantic with highs in the mid 50s and lows near freezing. The question remains where we go as this trough quickly moves through the region and out of the northern Middle Atlantic by the Wednesday to Thursday time frame. It looks like the pattern is transient with the generally trough axis shifting a bit eastward over the central Great Lakes. But still weak southeast ridging may allow for slightly above normal temperatures over the east coast. Latest ECMWF runs indicate a building negative EPO ridge over the west, which favors east coast troughing down the road. Generally looking ahead I do not see any extreme arctic blast as even the GFS has backed off on the long term arctic blast it was forecasting a few days ago. If anything the pattern looks relatively benign with near normal to slightly above normal temperatures. By as far as precipitation it appears the storm track remains active and very wet for the long term.
"Current NAO and PNA Predictions"
(Courtesy of NOAA)
"Monthly Temperature/Precipitation Outlook"(October)(Updated 9/13)
This monthly outlook is going to be posted a bit early this year for October. I never issued a September forecast and now it is the middle of the month so I decided to forecast October instead of the last two weeks in September. Therefore this outlook is a bit lower than normal for confidence. As many probably could guess I am going with a colder than normal October. Long term GFS especially is consistent with trough formation over the east coast and an amplified western ridge. Latest ECMWF is also steadfast, but not amplified with weaker western ridge and a weaker trough, but they are still evident. Teleconnections are a bit more favorable also for a cool pattern across the east coast. It appears the PNA will be spiking highly positive towards October 1 with the NAO and AO more towards neutral. As far as precipitation it appears near normal precipitation is likely with a drier start to the month gradually becoming more active. If the cooler than normal October verifies historical odds definitely favor a colder than normal with quite a bit of snow for the upcoming winter. I guess all we can wish for is not another October 2008 which was extremely mild and again followed by a mild winter. Looking on a more global perspective there is a building dome of cold air over the Arctic towards Greenland and northern Canada. This cold air will continue to build and likely be a catalyst for bits of cold air to break off and surge to the United States with strong cold fronts.
Temperature- As I already mentioned I believe this month will feature cooler than normal temperatures will a general trough over the Middle Atlantic. I think areas north of I-80 will have the colder anomalies as occasional stalled fronts affect southern Pennsylvania, Maryland and Delaware with clouds and precipitation while highs to the north allow radiational cooling for northern Pennsylvania. I am going with a general (-1)-(-2) temperature anomaly for most areas with a generally (0)-(-.5) for the metros of Philadelphia and Washington DC. Frosts and freezes do look likely for most all locations this month with periods of colder than normal weather. Especially early in the month frosts may occur with a high pressure over the region and a trough.
Precipitation- Precipitation looks to be near normal for the month with a dry start to the month as a strong high pressure looks to be over much of the eastern United States in a general benign weather pattern. Towards the middle of the month and the end the active storm track should resume similarities to earlier in the month of September. The subtropical jet will feature periods of storms tracking up the east coast. As far as snowfall, most likely at some point in the month areas, in the lake effect snow belts of Maryland and Pennsylvania will see at least flurries. It is too early to tell whether any system like October 2009 will affect the region.
"Temperature and Precipitation Outlooks from Climate Prediction Center for next 30 days"
(Courtesy of NOAA)
"Here 10mi Northeast of Harrisburg, PA 2009 Statistics"
(Severe Weather Stats...)
Severe Thunderstorm Watches- 8
Severe Thunderstorm Warnings- 9
Tornado Watches- 0
Tornado Warnings- 0
Total Thunderstorms- 33
Flood Watches- 4
Flood Warnings- 1
Monthly Precipitation- 6.19inches
Yearly Precipitation- 38.72inches
Heat Advisories- 2
Excessive Heat Warnings- 0
90degree Days- 9
Highest Temperature- 95degrees
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