Vencore Weather
24Jan/15Sat

11:45 AM | **Snow tomorrow night and Monday from a system that will then explode off the Northeast US coastline…more accumulating snow possible here Monday night/Tuesday along with brutal cold air…as far as the longer-term is concerned – buckle up for that as well!**

Discussion

Sunday night/Monday
As today’s coastal storm affects wind down along the I-95 corridor, another storm is already taking shape upstream. A “clipper” type of system is dropping southeastward today into the Northern Plains and it will reach the coastal waters of the western Atlantic Ocean by later Monday. Snow will move into the I-95 corridor region tomorrow night and continue on Monday with a big impact likely on the Monday morning commute along with possible school closings. This snow will be of the dry, fluffy variety - not like the wet snow that fell last night. Preliminary snowfall estimates by later Monday afternoon are as follows: DC region 3-6 inches, Philly region 3-6 inches, NYC region 2-4 inches.

Monday night/Tuesday
Once this system reaches the western Atlantic Ocean later Monday, the combination of the relatively warm ocean water and an influx of brutally cold Arctic air from the northwest will cause it to explode off the Northeast US coastline from late Monday into Tuesday. As a result, more accumulating snow could fall in the I-95 corridor on Monday night and Tuesday and it could be substantial. New England is quite likely to get walloped by an all-out wind-blown blizzard on Monday night and Tuesday and the I-95 corridor region from DC-to-Philly-to-NYC is going to be a close call. Brutal cold air reaches our region Monday night and it’ll last for much of the week. In fact, the overall weather pattern looks absolutely frigid for the foreseeable future – perhaps right through February -and there will be multiple snow threats.

Filed under: NYC, PHL, WMA Comments Off
23Jan/15Fri

10:00 AM | ****Unfolding weather pattern to bring significant snow and brutal cold to the Mid-Atlantic region during the next few weeks and perhaps right through the month of February****

Discussion

Overview
Some winters in the Mid-Atlantic region never bring significant snow. Some winters never feature the brutal cold that winter can offer. It is quite likely that we’ll get to experience both significant snow and brutal cold here in the Mid-Atlantic region during the next few weeks and that type of pattern with snow and cold could actually last right through the month of February. There will be numerous snow threats along the way beginning with the one from this evening into Saturday and then a second from Sunday night into Monday. In addition, brutal cold air outbreaks are likely to make numerous visits here as well during the next couple of weeks with the first one to arrive by Tuesday of next week. In fact, low temperatures by Wednesday morning could be sub-zero in many parts of the Northeast US and single digits in the I-95 corridor region from DC-to-Philly-to-NYC.

An especially interesting and scary-looking time period will be as we end January and begin February. Not only are there signs for a major coastal storm around February 1st (Super Bowl Sunday) or so, but brutal cold is likely to follow during the first few days of February that could bring temperatures to near zero again in many places across the Northeast US (see forecast map below for 2-meter temperature anomalies in the 5-day period from 2/2 to 2/7).

Feb_cold
[GFS 2-meter temperature anomaly forecast map for 5-day period of 2/2-2/7; map courtesy Weather Bell Analytics at weatherbell.com]

Temperatures and the connection to the 500 millibar height anomaly pattern
One week ago we discussed the likelihood for strong ridging to develop along the west coast of North America as we progress into the latter part of January. Indeed, the forecast map (below) from yesterday’s 12Z GFS Ensemble run for February 1st continues to insist on strong ridging (oranges) along the west coasts of Canada and the US and this type of upper air pattern usually leads to multiple Arctic air mass incursions into the northern US from northern Canada. In fact, this forecast map suggests that the upper-level winds at 500 millibars – which tend to follow the height anomaly lines - could actually bring air directly from the North Pole into the northeastern US by the beginning of February.

f228
[GFS Ensemble height anomaly forecast map for February 1st; courtesy Penn State eWall]

Short-term snow threats
Tonight/Saturday
Precipitation from an intensifying coastal storm should reach the DC metro region early this evening (5pm or so), the Philly region between 9pm – 11pm, and NYC between 1 and 3am. The main thumping of snow from this system will be on its front end before a changeover takes place to freezing rain and sleet and perhaps even to plain rain from the cities to the coast. This event is likely to end in the DC metro region by early tomorrow afternoon, late afternoon in Philly and early evening in NYC. Snow and ice accumulation estimates are as follows:

1-3 inches in the northern and western suburbs of the District; lesser amounts in DC and points south and east
3-6 inches in the Philly and NYC metro regions and in their northern and western suburbs; lesser amounts to the south and east

Sunday night/Monday
Another system will drop southeastward across the Great Lakes region late Sunday in much the same manner as some of the recent “clippers”. This system, however, has more potential than those as it will intensify in the Mid-Atlantic region on Monday, tap into some coastal moisture, and will have a cold air mass in place as it arrives. As a result, snow is likely to be the dominate precipitation type with this system on Sunday night and Monday and anywhere from several inches of snow are possible from DC-to-Philly-to-NYC. There is quite likely to be a significant disruption with the Monday morning commute due to the snowfall.

Buckle up, it’s going to be a wild ride.

Video

Filed under: Climate Info, NYC, PHL, WMA Comments Off
23Jan/15Fri

6:00 AM | **Winter storm arrives overnight…another storm generates accumulating snow here late Sunday night into Monday**

6-Day Forecast

Today

Mostly sunny, cold, highs in the upper 30’s

Tonight

Becoming cloudy, cold, snow develops after midnight, lows in the upper 20’s

Saturday

Snow changes to freezing rain and sleet and eventually to plain rain in the immediate metro region, freezing precipitation could hold on in the northern and western suburbs, cold, upper 30’s

Saturday Night

Snow possible early or a mixture of precipitation, total snow and ice accumulations in the 3-6 inch range are likely in the NYC metro region and points north and west, cold, upper 20’s

Sunday

Partly sunny, cold, mid-to-upper 30’s; snow possible late at night

Monday

Mostly cloudy, snow likely, cold, low 30’s

Tuesday

Mostly sunny, very cold, mid 20’s

Wednesday

Partly sunny, very cold, mid-to-upper 20’s

Discussion

A significant coastal storm will move from the Virginia coastline early tomorrow to just east of the Massachusetts coastline by Saturday night and the result will be some accumulating snow and ice in the I-95 corridor. This storm will undergo rapid intensification between tonight and tomorrow night as it treks northeastward just off the east coast. One important limiting factor for significant snow from this storm in the Mid-Atlantic region is the fact that there will be no Arctic air mass in place ahead of the system and no strong high pressure system will be located to the north during the event acting as an all-important cold air source. Nonetheless, despite a likely mixture of precipitation during this event, snow accumulations in the 3-6 inch range are likely in the NYC metro region given the expected storm track and rapid intensification which can "generate" its own cold air. The main thumping of snow from this storm will come on its front end later tonight into early Saturday.

Another system will drop southeastward across the Great Lakes region late Sunday in much the same manner as some of the recent “clippers”. This system, however, has more potential that those recent ones as it will intensify in the Mid-Atlantic region on Monday, tap into some Atlantic Ocean moisture, and will have a cold air mass in place as it arrives. As a result, snow is likely to be the dominate precipitation type with this system on Sunday night and Monday and several inches of snow accumulation is possible from DC-to-Philly-to-NYC. There is the strong likelihood that the Monday morning commute will be significantly disrupted by this early week snow event. Brutal cold air follows this second system and lows by Wednesday morning will likely reach the single digits.

Video

Filed under: NYC Comments Off
23Jan/15Fri

6:00 AM | **Winter storm arrives early this evening…another storm generates accumulating snow here Sunday night into Monday**

6-Day Forecast

Today

Increasing clouds, cold, snow or snow and sleet arrives at the end of the day, highs near 40 degrees

Tonight

Cloudy, cold, snow or snow and sleet early this evening likely mixing with freezing rain late, lows in the lower 30’s

Saturday

Mixed precipitation changes to plain rain except possibly in the far northern and western suburbs where freezing can still occur, cold, total snow and ice accumulations in the 1-3 inch range are likely in the northern and western suburbs of the District, lesser amounts in the District and points south and east, upper 30’s

Saturday Night

Becoming partly cloudy, cold, mid-to-upper 20’s

Sunday

Partly sunny, cold, mid-to-upper 30’s; snow likely at night

Monday

Mostly cloudy, snow likely, cold, mid 30’s

Tuesday

Mostly sunny, very cold, upper 20’s

Wednesday

Partly sunny, very cold, upper 20’s

Discussion

A significant coastal storm will move from the Virginia coastline early tomorrow to just east of the Massachusetts coastline by Saturday night and the result will be some accumulating snow and ice in the I-95 corridor. This storm will undergo rapid intensification between tonight and tomorrow night as it treks northeastward just off the east coast. One important limiting factor for significant snow from this storm in the Mid-Atlantic region is the fact that there will be no Arctic air mass in place ahead of the system and no strong high pressure system will be located to the north during the event acting as an all-important cold air source. Nonetheless, despite a likely mixture of precipitation during this event, total snow and ice accumulations in the 1-3 inch range are likely in the northern and western suburbs of the District given the expected storm track and rapid intensification which can "generate" its own cold air. The main thumping of snow from this storm will come on its front end later this evening.

Another system will drop southeastward across the Great Lakes region late Sunday in much the same manner as some of the recent “clippers”. This system, however, has more potential that those recent ones as it will intensify in the Mid-Atlantic region on Monday, tap into some Atlantic Ocean moisture, and will have a cold air mass in place as it arrives. As a result, snow is likely to be the dominate precipitation type with this system on Sunday night and Monday and several inches of snow accumulation is possible from DC-to-Philly-to-NYC. There is the strong likelihood that the Monday morning commute will be significantly disrupted by this early week snow event. Brutal cold air follows this second system and lows by Wednesday morning will likely reach the single digits.

Video

Filed under: WMA Comments Off