Thomas is an avid weather enthusiast, landscaper and organic gardener. This blog is dedicated to Northeast and tropical weather forecasting. Enjoy!
By: sullivanweather , 9:20 AM GMT on November 27, 2008
Current watches, warnings and advisories.
Synopsis - Issued 11/27 @4:20am
Lake enhanced snow showers will linger through Thanksgiving as the pesky upper low that has brought unsettled weather to the Northeast over the last several days slowly rotates north towards Hudson Bay. A weak clipper blows by the region on Black Friday with light showery precipitation mainly confined to the North Country then a possible winter storm will move up the Eastern Seaboard as a deep trough carves out over the Ohio Valley late this weekend into early next week.
Short-term - Issued 11/27 @4:20am
Vertically stacked low pressure over southern Ontario will finally begin to move north today, away from the Northeast, but we will still feel some of the fringe effects of this system as lake enhanced snow showers continue across upstate New York in cold, moist cyclonic flow. Areas in and around the Adirondacks and St.Lawrence River Valley/Thousand Island region remain under lake effect snow warnings/advisories as anywhere from 3-10 inches of snow can be expected between the time of this writing and late tonight. The Niagara Frontier will also see some lake enhanced snow showers but accumulations will be much lighter, on the order of an inch or two, as deeper moisture has left this region and the air aloft warms, reducing lake induced instabilities. Additional flurries and snow showers extend over central New York and north-central Pennsylvania but these won’t amount to anything more than a dusting and should end by the late morning. Elsewhere across the region skies will be party to mostly clouds, meaning that there will be some periods of sunshine for the first time in many days for some areas. Temperatures will still run near to slightly below normal. Highs will range from the 30’s across the interior, with 40’s across the interior river valleys, such as the Hudson, Susquehanna and Connecticut, as well as along the coastal plain. A few locations may even may the low 50’s across southern New Jersey and extreme southeastern Pennsylvania around the Philadelphia area. Winds will be out of the west to west-southwest around 5-10mph.
Lake effect winds down tonight across upstate New York as the remainder of the region stays dry. High clouds will increase after midnight as a fairly weak clipper system drops down out of the Great Lakes region towards the Northeast. Lows will fall into the 20’s across the north, with a few teens in the higher terrain, with 30’s along the coastal plain. Winds will be generally under 5mph.
Aforementioned clipper low slides through the Northeast on Black Friday, bringing nothing more than an increase in mid/high clouds and perhaps a few snow showers to the higher terrain of northern New York and New England. Once again, temperatures will be seasonal, with highs ranging from the 30’s across the north with 40’s across the southern interior and New England coastal plain. From the New York City metropolitan area on south across the I-95 corridor temperatures should crack the 50°F mark once again. Winds will be from a southerly direction at 5-10mph, shifting from the west after an afternoon cold frontal passage around the same speeds.
The moisture-starved clipper is finally able to tap into some Atlantic moisture that could bring an inch or so of snow across Downeast Maine Friday night. A few snow showers may come off the lakes as weak cold air advection drops 850mb temps down to –6 to –8°C, creating marginal/conditional lake instability parameters, but these won’t amount to much. The remainder of the region will see partly cloudy skies. Lows will range from the 20’s across the interior to the 30’s along the coastal plain.
The clipper will be pulling out to sea by Saturday morning, leaving behind fair skies and a continuation of seasonable temperatures. A couple nuisance flurries will dot the Tug Hill Plateau/Adirondacks region but these won’t amount to anything.
Mid-term - Issued 11/27 @4:20am
Lots of uncertainty in the mid-term as a complex interaction of northern and southern stream disturbances will make for a very challenging forecast. Models do agree that there will be some level of phasing between the two branches of the jet, which will ultimately lead to cyclogenesis somewhere across the Southeast, as the northern stream branch of the jet buckles into a deep trough over the Mississippi/Tennessee Valley. What track the low takes from there is where the models are at odds with each other. The GFS is showing more of an inland runner due to a deeper trough and greater phasing, with the rain/snow line pushing into the interior. On the other hand, the ECMWF, GGEM, UKMET models show less phasing and an offshore track to the low pressure. This puts the rain/snow line much further southeast, bringing more snow to the interior, although QPF is much less than the GFS. Bottom line is that a storm will be affecting at least the southern half of the region to close out the holiday weekend and any traveling plans may need to be pushed up a day to Saturday to avoid delays, especially across the interior. Low pressure moves into New England on Monday with the upper trough axis swinging through keeping unsettled weather over the Northeast. Temperatures will return back to slightly below seasonal averages for late November.
Long-term - Issued 11/27 @4:20am
In the long term, the GFS lifts out the trough, bringing a moderating trend to the region on Tuesday and Wednesday before a cold front blasts through the region on Thursday bringing much colder air back over the Northeast for Friday into next weekend. This solution has little support from other global models, which lingers the trough over the region, keeping the cooler air locked over the Northeast. In addition, a clipper system is progged to drop down from Canada by the GGEM/ECMWF, reaching the Northeast by Wednesday bringing renewed chances for snow across the interior and rain to the coastal plain. In fact, both of these models maintain an active storm track across the eastern US the second half of next week into next weekend with plenty of cold air around for wintry precipitation types. Since the models have shown very little consensus beyond next Tuesday I’ll forego mentioning any individual systems until better run to run consistency develops.
Radar: Northeast Region Loop
2008-09 Winter Forecast
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