7:00 AM | Mild today through Monday, but another cold shot follows for Tuesday/Wednesday

6-Day Forecast

Today

Mostly sunny, noticeably milder, highs near 60 degrees

Tonight

Mostly cloudy, not as cold as recent nights, maybe a shower late, lows in the low 40’s

Saturday

Partly sunny, mild, near 60

Saturday Night

Mostly cloudy, cool, maybe a shower, upper 40’s

Sunday

Mostly cloudy, mild, showers likely, mid 60’s

Monday

Mostly cloudyin the morning with showers likely then afternoon clearing, mild, mid 60’s

Tuesday

Mostly sunny, windy and colder, mid-to-upper 40’s

Wednesday

Mostly sunny, cold, low 40's

Discussion

There is good news and bad news with respect to the temperature department for the next several days. The good news is that temperatures will climb this weekend and into the first part of next week to noticeably milder levels. The bad news is that another strong cold front will plow through the region on Monday and much colder air will return for Tuesday and Wednesday. In fact, this next cold shot could be as cold as or even colder than the air mass we just suffered through this week.

7:00 AM | Another chilly day, but milder air returns tomorrow; another strong cold front on the horizon

6-Day Forecast

Today

Mostly sunny, still chilly for this time of year, but not quite as cold as yesterday, highs near 55 degrees

Tonight

Mostly clear, cold, lows near 30 degrees

Friday

Mostly sunny, milder, upper 50’s

Friday Night

Mostly cloudy, not as chilly as recent nights, low 40’s

Saturday

Partly sunny, cool, upper 50’s

Sunday

Mostly cloudy, mild, showers possible, low-to-mid 60's

Monday

Mostly cloudy, mild, some rain likely, mid 60’s

Tuesday

Mostly sunny, windy, colder, upper 40's

Discussion

Strong high pressure that has anchored this unseasonal Arctic air mass will drift towards the east coast today and then shift off the coast on Friday. This movement will allow for a shift in low levels winds to a south-to-southwest direction by the weekend which will pump in milder air. Along with the milder conditions, there will be an increasing shot at showers by the end of the weekend and Monday looks to be wet as another strong cold front passes through the region. It’ll turn colder and windy on Tuesday and Wednesday following the frontal passage as yet another colder-than-normal air mass pushes into the Mid-Atlantic region.

Video

httpv://youtu.be/jzNsARVgnpw

7:00 AM | Another day with Arctic chill and temperatures way below normal; much milder by the weekend

6-Day Forecast

Today

Mostly sunny, brisk and quite cold, highs in the low 40’s

Tonight

Mostly clear, very cold, lows in the mid-to-upper 20’s

Thursday

Mostly sunny, still chilly for this time of year, but not as cold as Wednesday, low-to-mid 50’s

Thursday Night

Mostly clear, cold, near 30

Friday

Mostly sunny, cool, mid 50’s

Saturday

Partly sunny, cool, mid-to-upper 50’s

Sunday

Mostly cloudy, mild, showers possible, near 60

Monday

Mostly cloudy, mild, some rain likely, low 60's

Discussion

The core of the cold Arctic air mass is sitting on top of the region this morning and today will turn out to be another day with well below normal temperatures. High temperatures this afternoon will struggle to pass the 40 degree mark despite plenty of sunshine and wind chills will be even lower. Some modification in temperatures will occur on Thursday and then the rebound will intensify this weekend. In fact, high temperatures on Sunday afternoon could be some twenty degrees warmer than today although showers may dampen that milder weather. It stays mild on Monday with some rain likely as the next cold front sweeps towards us and that frontal passage will likely usher in another cold air mass on Tuesday.

Video

httpv://youtu.be/EjtdOOvt3OM

12:00 PM | 2013-2014 Winter Outlook for the Mid-Atlantic Region

Video

httpv://youtu.be/KMh5WcZwBCo

Discussion

Looks like the Mid-Atlantic region is leaning towards the colder and snowier side of normal for the upcoming winter of 2013-2014…

Recap of last winter Last winter featured warmer-than-normal conditions in the Mid-Atlantic region during December and January, but then temperatures slid to slightly below normal during February and well below normal in March. Perhaps the most memorable feature from last winter is that there, in fact, were no memorable snowstorms. While several small snow accumulation events did occur in the region, there were no significant storms last winter with anything above 4 inches or so. This winter, however, should feature some episodes in which the timing will be just right between cold air outbreaks, an active southern jet, and storminess to produce significant snow events.

There are three major factors that will play an important role in the winter weather around here:

1) Lack of a strong El Nino/Southern Oscillation (ENSO) signal in the tropical Pacific Ocean 2) Low solar activity that frequently leads to high latitude blocking and, in turn, Arctic air outbreaks for the central and eastern US 3) Above normal snowpack across the Northern Hemisphere

Neutral ENSO signal in the tropical Pacific Ocean All indications are that the sea surface temperature (SST) anomalies in the tropical Pacific Ocean will stay rather close to neutral during the upcoming winter season. It is very likely that there will be not be a strong El Nino (warmer-than-normal SSTs) or La Nina (colder-than-normal SSTs) any time soon in the tropical Pacific Ocean and that tends to open the door for a bigger influence around here from another part of the world such as in the northern latitudes and the North Atlantic Ocean. A strong signal from the tropical Pacific Ocean would typically become the dominating factor with respect to Mid-Atlantic winter weather no matter what takes place elsewhere around the world; however, with a neutral signal expected this winter, it is time to look elsewhere.

Low solar activity and high latitude blocking Research has shown that low solar activity tends to lead to the formation of a blocking pattern in the high latitudes (e.g., Greenland) during winter months which, in turn, leads to numerous Arctic air outbreaks into the central and eastern US from central Canada. While we are actually in a period of solar maximum for the current solar cycle, #24, it happens to be one of the weakest solar cycles in many decades and low solar activity is expected to continue this winter. Indeed, a look at numerous analog years with low solar activity reveals an unmistakable signal for high latitude blocking during winter months. This type of blocking pattern can be tracked through an index called the North Atlantic Oscillation (NAO) which would typically turn negative in times of high latitude blocking, and I expect that to happen frequently during this upcoming winter season as this may turn out to be the most important factor of all.

Above-normal snowpack in the Northern Hemisphere An important source region for cold air in this part of the US during the winter season is Eurasia - on the other side of the North Pole - and studies have shown that when snowpack increases in that part of the world during the month of October, and is above normal at the end of the month, then Arctic cold air outbreaks are sure to follow during the subsequent winter months in the central and eastern US. Indeed, snow cover in Eurasia increased dramatically during October reaching above normal levels by the end of the month. In fact, the Eurasian snowpack reached the 4th highest level in the past 46 years and the entire Northern Hemisphere snow cover reached the 7th highest level in that same 46 year period.

Summary of Winter Outlook for the Mid-Atlantic Region: The Mid-Atlantic region will lean towards the colder and snowier side of normal with temperatures some 0.5 to 1.0 degrees below normal for the winter season (November through March) and snowfall at 100-140% of normal. Normal snowfall amounts (which should be the minimal amounts this winter) are as follows: 15” at DCA, 21” at BWI, 21” at PHL, 29” at Central Park, NY

7:00 AM | Arctic chill for the next couple of days; temperatures drop this morning with scattered rain and/or snow showers and increasing northerly winds

6-Day Forecast

Today

Morning clouds and possible rain and/or snow showers will give way to mostly sunny skies this afternoon with windy and cold conditions, temperatures this afternoon holding near 40 degrees after dropping this morning

Tonight

Partly cloudy, brisk, very cold, lows in the mid-to-upper 20’s

Wednesday

Mostly sunny, brisk and cold, low-to-mid 40’s

Wednesday Night

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

Thursday

Mostly sunny, cold, upper 40’s

Friday

Mostly sunny, chilly, mid 50’s

Saturday

Partly sunny, cool, maybe a shower, mid-to-upper 50’s

Sunday

Mostly cloudy, mild, showers possible, near 60

Discussion

An Arctic front has passed through the region and there are a few rain and snow showers immediately behind the front that will move into the region later this morning. The afternoon will bring about clearing skies, but with windy and cold conditions and temperatures will hold near 40 degrees after dropping this morning. Strong Canadian high pressure will push towards the east coast over the next couple of days and it is anchoring an Arctic air mass that will result in some of the coldest temperatures yet this season across portions of the East and Deep South. The unseasonal chill should last through Thursday, but then as the high approaches the east coast late this week, the low-level flow will back around to a southwesterly direction and temperatures will rebound quite nicely by the weekend.

Video

httpv://youtu.be/Ce6_Mwf8s3Q

1:30 PM | Flakes could accompany the arrival of the Arctic blast

Discussion

An Arctic front will arrive in the region during the pre-dawn hours and while there won’t be a lot of precipitation associated with the frontal system, some of it will occur behind the front in the increasingly colder air. As a result, there can be a rain shower or two later tonight and then, after the surface cold front has passed through the region, snow showers could fall towards morning and right into the mid-morning hours. The winds will abruptly switch from the southwest to northwest at the time of the frontal passage and will pick up in intensity by tomorrow afternoon. Despite increasing amounts of sunshine Tuesday afternoon, temperatures will struggle to pass the low 40’s which is way below normal for this time of year (normal highs: 56 in Central Park, NY; 58 at PHL, and 60 at DCA). Tomorrow night promises to be perhaps the coldest night yet this season, but the cold snap will only last through Thursday as temperatures should rebound rather nicely at the end of the week.

7:00 AM | An Arctic blast arrives tomorrow morning

6-Day Forecast

Today

Partly sunny, chilly, highs in the mid 50’s

Tonight

Mostly cloudy, becoming breezy, turning cold late, rain showers possible before midnight and snow showers possible towards morning, lows in the mid 30’s

Tuesday

Clouds in the morning with scattered snow showers possible then mostly sunny, windy and very cold for the afternoon, low-to-mid 40’s

Tuesday Night

Mostly clear, cold, mid-to-upper 20’s

Wednesday

Mostly sunny, very cold, low 40’s

Thursday

Mostly sunny, cold, upper 40’s

Friday

Mostly sunny, chilly, low-to-mid 50’s

Saturday

Partly sunny, cool, mid-to-upper 50’s

Discussion

An Arctic blast will move into the region early Tuesday accompanied by some rain and snow shower activity and the unseasonal chill will last through Thursday. A very strong high pressure system is anchoring this cold air mass and it will head from the middle of the country today towards the eastern states over the next couple of days. By late this week, as the high shifts to the coast and a southwest flow develops, temperatures will rebound back to near normal conditions and the milder weather should last for several days before another cold front pushes in.

Video

httpv://youtu.be/nSXcxb4pvrU

1:40 PM | Arctic cold is coming next week...coastal storm may stay offshore

Discussion

Yesterday we talked about an extremely strong Arctic high pressure system that is headed into the northern US by early next week and it will indeed send an Arctic cold frontal system through the Mid-Atlantic region on Tuesday. In fact, the coldest air mass of the season will invade much of the eastern half of the nation next week in the Tuesday, Wednesday, Thursday time frame. An east coast storm will try to get organized later next week, but the widespread cold air intrusion may very well keep it far enough offshore to prevent any snow possibilities in the Mid-Atlantic region. The US GFS model runs of recent days has featured more of an “out to sea” solution and the latest 12Z Euro model has now flipped from a “coastal-hugging storm” to more of an “out to sea” solution - similar to the GFS. An "out to sea" solution is certainly feasible given the strength and track of the incoming high pressure system. It is all still several days away so there is still some time for this potential scenario to change. The Arctic cold air is certainly coming, but the coastal storm may form too late to affect the I-95 corridor between DC and NYC. Stay tuned.

7:00 AM | Much colder air has moved into the region and it stays chilly through the weekend

6-Day Forecast

Today

Mostly sunny, becoming windy and noticeably colder than yesterday, highs in the low 50’s

Tonight

Mostly clear, quite cold, lows near 30 degrees

Saturday

Mostly sunny, chilly, mid-to-upper 50’s

Saturday Night

Partly cloudy, cold, mid-to-upper 30’s

Sunday

Mostly sunny, windy and chilly, mid-to-upper 50’s

Monday

Mostly sunny, still chilly, mid 50’s

Tuesday

Increasing clouds, cold, upper 40’s

Wednesday

Mostly cloudy, cold, chance for rain or snow, low-to-mid 40’s

Discussion

Much colder air has moved into the Mid-Atlantic region following the passage of yesterday’s cold frontal system and it will stay chilly right into the early part of next week. Another shot of very cold air for this time of year will reach the eastern states by the middle of next week anchored by a remarkably strong high pressure system dropping southward from central Canada. There is even the potential for some snow in parts of the Mid-Atlantic region later next week as a storm tries to take shape near the east coast.

Video

httpv://youtu.be/jWQxzKEXinc

12:15 PM | Could there be a snowstorm next week?

Discussion

It is that time of year again and let the games begin! If the last couple of years have proven anything from a weather point of view it is that accumulating snow in October and early November is not impossible in this part of the country. While there certainly has been some inconsistency among the numerous computer forecast models and it is several days away, an interesting scenario is unfolding for the middle and latter parts of next week that could result in the first accumulating snows in parts of the Mid-Atlantic region.

A very chilly air mass for this time of year will drop into the Northern Plains early next week anchored by an impressively strong Canadian high pressure system. As is often the case around here in the Mid-Atlantic region during winter storm events, the high pressure system may be the key as to how much precipitation may fall around here later next week and of what form will it be. It appears that this remarkably strong high pressure system will ultimately break into two segments with one part heading southward into the Tennessee Valley and significantly, a second part builds into New England. The result will be an imposing “banana-shaped” high pressure region that will extend from the Midwest to New England and this type of pressure pattern typically can indeed support the funneling of cold air southward into the Mid-Atlantic region from New England. Both the 00Z GFS and European computer forecast models develop this “banana-shaped” high pressure system later next week at the same time a storm forms near the east coast, but exactly where that storm winds up is still to be determined. Stay tuned, everything has to come together for accumulating snow in November in the Mid-Atlantic region (really that holds true for any time of year), but the potential is there for the first time this season. More details on the 00Z computer forecast model runs in today’s video discussion.

Video

httpv://youtu.be/QFhOSt_ElNo