7:00 AM | Continued chilly and breezy today, but much more pleasant weather coming for the latter part of the week

6-Day Forecast

Today

Mostly sunny, breezy, cool, highs near 60 degrees

Tonight

Mostly clear, cold, mid 40’s

Wednesday

Mostly sunny, still quite cool, low 60's

Wednesday Night

Mostly clear, not as cold, upper 40’s

Thursday

Mostly sunny, milder, near 70

Friday

Mostly sunny, mild, near 70

Saturday

Mostly sunny, mild, upper 60’s

Sunday

Mostly sunny, mild, upper 60’s

Discussion

Chilly and breezy conditions will continue around here for another day and then an offshore flow and a building ridge of high pressure will begin a mid-week warming trend. Pleasant weather will rule for the second half of the week with highs back to the 70 degree mark.

Video

httpv://youtu.be/8HeDMr1Mz10

2:15 PM | **The North Pole To Visit the US**

Discussion

A surface cold front has slipped through the I-95 corridor this morning and the Mid-Atlantic region will gradually get back to more seasonal conditions over the next 12-18 hours or so, and then we’ll take another step down in temperatures come Thursday night and Friday following the passage of another cold front; however, that air mass will modify some during the upcoming weekend and the real change in the overall weather pattern will begin early next week.

For a couple of weeks we’ve been talking about a major sudden stratospheric warming (SSW) event that has occurred at high latitudes and it has indeed set off a change of events in the atmosphere that should lead to multiple very impressive cold air outbreaks into the central and eastern US beginning early next week. Major SSW events have in recent decades generated quite dramatic turnarounds in temperature patterns for this part of the world and prospects are growing for the same kind of result this winter from this latest upper-atmospheric episode. Two such major events that bear some similarities to this year occurred during December 1984/January 1985 and December 1998/January 1999 (and they are detailed in the stratospheric warming video in our “Meteorology 101” section). The outbreak of cold air early next week should be quite widespread ranging from the Northern Plains where there will be below zero readings to the Deep South where a rare chill will develop. As far as the Mid-Atlantic region is concerned, the potential is there for temperatures to plunge to at least as low as the single digits in Philly and New York City in the next 7-10 days or so and highs could stay below freezing in DC for much of next week. Stay tuned over the next few days as we fine-tune this frigid outlook for next week and beyond.

Video

httpv://youtu.be/K1Idin8RWcE

7:00 AM | Bitter cold air starts the new week, but much improvement coming

6-Day Forecast

Today

Early morning light snow possible; otherwise, partly sunny skies, very cold, highs in the mid-to-upper teens

Tonight

Mostly clear, bitter cold, low single digits for lows

Tuesday

Partly sunny, not as cold, near 30

Tuesday Night

Partly cloudy, cold, low 20’s

Wednesday

Mostly sunny, milder, mid-to-upper 40’s

Thursday

Partly sunny, mild, upper 40’s

Friday

Mostly sunny, still mild, mid-to-upper 40’s

Saturday

Partly sunny, still mild, mid-to-upper 40’s

Discussion

Bitter cold air moved in over the weekend and the new week will start on the cold side with highs no better than 20 degrees. Temperatures will plunge to the single digits tonight and then a gradual warming trend begins on Tuesday. In fact, by the middle of the week our high temperatures are likely to rise well up into the 40’s.

Video

httpv://youtu.be/225XDoPxxoI

7:00 AM | Gusty winds and continued unseasonable chill begin the new week

6-Day Forecast

Today

Mostly sunny, windy, cool, highs in the mid 50’s

Tonight

Mostly clear, breezy, cold, mid 40’s

Tuesday

Mostly sunny, breezy, still quite cool, low 60’s

Tuesday Night

Mostly clear, cold, mid 40’s

Wednesday

Mostly sunny, still quite cool, low 60’s

Thursday

Mostly sunny, cool, mid-to-upper 60’s

Friday

Mostly sunny, cool, mid 60’s

Saturday

Mostly sunny, cool, mid 60’s

Discussion

Cold air moved in over the weekend and it’ll remain on the chilly side through tonight to start the new week. In fact, temperatures late tonight will be near record lows in many spots in central and southern California. Slight improvement in temperatures is likely on Tuesday and highs in the 60’s will be common for much of the rest of the week.

Video

httpv://youtu.be/225XDoPxxoI

7:00 AM | Arctic air returns today and sticks around into next week; brutal cold for the Broncos game tomorrow afternoon

6-Day Forecast

Today

Partly sunny, windy, much colder, snow showers possible, highs in the mid 30’s early in the day and then falling through the 20's this afternoon

Tonight

Mostly cloudy, breezy, very cold, snow showers possible, lows in the single digits

Saturday

Mostly cloudy, windy, bitter cold, scattered snow showers with small accumulations, highs in the middle teens with much lower wind chills

Saturday Night

Mostly cloudy, brutal cold, breezy, snow showers, lows not far from 0 degrees

Sunday

Mostly sunny, very cold, highs near 20

Monday

Partly sunny, cold, mid 20’s

Tuesday

Mostly sunny, cold, near 30

Wednesday

Partly sunny, not as cold, mid 40’s

Discussion

Our January thaw is over as Arctic air has moved into the region and it will stay quite cold right into the early part of next week. An upper low will moves from the Great Basin into Wyoming and there can be some snow shower activity over the next 24 hours in and around the Denver metro region with several inches of snow possible in the mountains north of the I-70 corridor.

Video

httpv://youtu.be/-seh01wHchQ

7:00 AM | Coldest air yet this season to cause a damaging freeze in many valley locations late tonight/early Saturday

6-Day Forecast

Today

Mostly sunny, breezy, unseasonably cool, highs only reaching the mid 50’s

Tonight

Mostly clear, unseasonably cold, possible damaging frost in some coastal valley locations, upper 30’s

Saturday

Mostly sunny, breezy, unseasonably cool, low-to-mid 50’s

Saturday Night

Mostly clear, cold, low 40’s

Sunday

Mostly sunny, still quite cool, mid 50’s

Monday

Mostly sunny, cool, mid 50’s

Tuesday

Mostly sunny, not quite as cool, near 60

Wednesday

Mostly sunny, cool, near 60

Discussion

The coldest air of the season so far has moved into the region as a strong, cold upper level low pressure system has moved in from the north. The below normal temperatures will continue into early next week and tomorrow morning could very well feature the lowest temperatures so far this winter with a potentially damaging freeze event in many coastal valley locations.

Video

httpv://youtu.be/-seh01wHchQ

12:20 PM | Major stratospheric warming event splits polar vortex; dramatic temperatures changes coming to the Mid-Atlantic later next week

Discussion

A milder weather pattern continues here in the Mid-Atlantic region and it will remain into the early part of next week with a peak in temperatures to occur this weekend. By the middle of next week, however, another pattern change will begin to be seen in the northeastern US and it could become quite dramatic. A major “sudden stratospheric warming” (SSW) event has occurred during the last week or so and it has resulted in a breakdown of the stratospheric polar vortex. In fact, the normally “single-entity” upper-atmosphere vortex has split into two as a result of this dramatic SSW event.

A major SSW event such as this is seemingly setting off a series of events that will soon lead to a resurgence of cold air masses into the central and eastern US. Specifically, the SSW event suppresses and cools the troposphere and weakens the polar jet stream which, in turn, helps to generate high latitude blocking in the atmosphere. Once the blocking becomes established, usually near Greenland, it acts to force the coldest air normally bottled up over the Arctic to move southwards into the mid-latitudes. This whole process of Arctic cold spilling southward to the surface levels in the mid-latitudes typically occurs some 10-20 days after the initial sudden stratospheric warming and the change to a cold pattern can last for a few weeks. The blocking in the atmosphere at high latitudes can be tracked through the Arctic Oscillation (AO) and North Atlantic Oscillation (NAO) indices which, when negative, indicate blocking is occurring in the North Atlantic region. Indeed, these indices are in the process of changing from slightly positive readings to negative values as this SSW event continues to unfold and impact the global weather patterns.

The bottom line, after a significant warm up that peaks this weekend in the Mid-Atlantic with a “spring fever alert”, the overall weather pattern here will likely change to colder-than-normal towards the middle and latter part of next week and that change to cold could persist for awhile. The first waves of cold air as a result of this pattern change will strike the western and central US, but by later next week, they should reach the northeastern states. There is the potential that during the time period from mid-January to early February parts of the US experience some of the coldest air seen in quite some time and snow chances will no doubt be on the rise. One final note, on the other side of the pole, brutal cold air will invade a very large area from Europe to Asia over the next couple of weeks – perhaps some of the coldest air seen there in several decades.

Video

httpv://youtu.be/N_Dw_jWtQq0

7:00 AM | Coldest air of the season so far floods southern California over the next couple of days; potentially damaging freeze event by early Saturday in the coastal valleys

6-Day Forecast

Today

Considerable clouds, windy, cool, showers likely, highs holding in the mid 50’s

Tonight

Partly cloudy, windy and cold, lows in the mid 40’s

Friday

Mostly sunny, breezy, cold, low-to-mid 50’s

Friday Night

Mostly clear, breezy, very cold, upper 30’s; potential damaging freeze by early morning in some coastal valley locations

Saturday

Mostly sunny, quite cool, mid 50’s

Sunday

Mostly sunny, cool, upper 50’s

Monday

Mostly sunny, cool, near 60

Tuesday

Mostly sunny, cool, near 60

Discussion

The coldest air of the season so far will pour into the region on Thursday and Friday as a strong, cold low pressure system approaches from the north. Showers can accompany this change to cold and winds will be quite gusty at times out of the north. The below normal temperatures will continue into early next week and Saturday morning could very well feature the lowest temperatures so far this winter with a potentially damaging freeze event possible in coastal valleys.

Video

httpv://youtu.be/HQ_OSJVvTGI

7:00 AM | Dramatic change to Arctic cold to end the week; bitter cold continues through the weekend

6-Day Forecast

Today

Mostly sunny, breezy, still mild, highs in the mid 50’s

Tonight

Mostly cloudy, cold, lows in the mid 20’s

Friday

Mainly cloudy, windy, much colder, some snow possible, low 30’s

Friday Night

Mostly cloudy, very cold, some more snow possible, lows near 10 degrees

Saturday

Mostly cloudy, very cold, near 20

Sunday

Partly sunny, very cold, near 20

Monday

Mostly sunny, very cold, low 20’s

Tuesday

Partly sunny, very cold, upper 20’s

Discussion

Our January thaw will continue for one more day as temperatures will likely to move up into the 50’s again which is way above normal for this time of year. However, a major change is about to take place as it’ll turn much colder by tomorrow and that transition back to winter could be accompanied by some snow. An Arctic cold front will usher in the dramatic change and the very cold temperatures will persist right through the upcoming weekend.

Video

httpv://youtu.be/HQ_OSJVvTGI

7:00 AM | What a difference between today and Friday!

6-Day Forecast

Today

Mostly sunny, unseasonably mild, highs in the mid 50’s

Tonight

Mostly clear, becoming windy, colder late, lows in the upper 20's

Thursday

Mainly sunny, still unseasonably mild, mid-to-upper 50’s

Thursday Night

Mostly cloudy, turning much colder late, mid 20’s

Friday

Mostly cloudy, much colder, maybe some snow, low 30’s

Saturday

Partly sunny, very cold, near 20

Sunday

Mostly sunny, very cold, low 20’s

Monday

Partly sunny, very cold, mid 20’s

Discussion

The January thaw will continue today and tomorrow with high temperatures likely to move well up into the 50’s - way above normal for this time of year. However, a major change is about to take place as it’ll turn much colder by Friday and that transition back to winter could be accompanied by some snow. The very cold temperatures will persist right through the upcoming weekend.

Video

httpv://youtu.be/x9ILedcyOPA