1:55 PM | The latest on the upcoming colder weather pattern in the Mid-Atlantic and current sunspot activity

Discussion

November continues to run below normal in terms of temperatures in the Mid-Atlantic region and all signs point towards a cold finish to the month with two separate outbreaks of Arctic air. The first outbreak will occur this weekend and it will result in the first widespread, albeit rather short-lived, “lake-effect” snow event of the season so far in places downstream of Lakes Erie and Ontario. Snow flurries/showers and even heavier squalls will occur from late Friday night into early Sunday in the Appalachian Mountains from West Virginia to New England, and a flurry can make it all the way down to the suburbs of the big cities along I-95. After a slight relaxation in temperatures on Monday and Tuesday, another widespread cold air outbreak is expected by the middle of next week and this will send temperatures to well below normal levels from the Central Plains to the Mid-Atlantic coast. Looking even further ahead, there are signs for more cold air outbreaks during the month of December based on the overall pattern change that is now underway. Specifically, the North Atlantic Oscillation (NAO) is about to tank deeper into negative territory which often promotes numerous cold air outbreaks into the northeastern part of the country. The NAO index was talked about at length in the winter outlook video (home page) released several weeks ago as to one of the reasons why a cold and snowy winter is predicted for the Mid-Atlantic region.

Meanwhile, as far as the sun is concerned, yesterday we talked about two large sunspot regions called AR1619 and AR1618 that are now facing the Earth in a pretty direct fashion. AR1618 has now grown to a region 10 times the size of the Earth and it has been active during the past 24 hours resulting in M-class solar flares that appear to have propelled coronal mass ejections towards Earth. If so, the impacts would likely occur on November 23rd with the chance then for some high-latitude auroras. More eruptions are possible from both of these sunspot regions over the next 24-48 hours.

7:00 AM | Decent weather by afternoon on Thanksgiving Day, warmer to close out the week

6-Day Forecast

Today

Low clouds and fog early then gradually becoming partly sunny, still cool, highs in the mid 60’s

Tonight

Mostly clear early, low clouds and fog possible late, cool, lows in the mid 50’s

Turkey Day

Low clouds and fog early then gradually becoming partly sunny, cool, mid-to-upper 60’s

Thursday Night

Mostly clear, cool, mid 50’s

Friday

Mainly sunny, milder, low 70’s

Saturday

Partly sunny, mild, low-to-mid 70’s

Sunday

Mostly sunny, mild, near 70

Monday

Partly sunny, a bit cooler, mid 60’s

Discussion

The weather looks pretty decent for Turkey Day as high pressure builds into the region with weak offshore flow. Temperatures will return to above normal levels on Friday and Saturday as more ridging and offshore flow will continue, but there may be a cooling trend at the beginning of next week.

Video

httpv://youtu.be/oG7qIk6rP3U

7:00 AM | Mild pattern continues with 70 degrees within reach this afternoon

6-Day Forecast

Today

Mostly sunny, warm, highs near 70 degrees

Tonight

Mostly clear, cold, lows in the upper 30’s

Turkey Day

Mostly sunny, breezy, cooler, mid 50’s

Thursday Night

Mostly clear, cold, upper 20’s

Friday

Mainly sunny, chilly, low 50’s

Saturday

Mostly sunny, not as chilly, upper 50’s

Sunday

Mostly sunny, cool, low-to-mid 50’s

Monday

Mostly cloudy, colder, maybe a few snow showers, upper 30's

Discussion

The warm up that began yesterday will continue today as high pressure pushes to our east setting up a nice southwesterly flow of air into the region. Temperatures this afternoon will approach or even surpass the 70 degree mark – well above normal for this time of year. Normal highs this time of year for the Denver region have dropped to just under the 50 degree mark at 49 degrees. It will turn noticeably cooler for Turkey Day, but some sunshine is still in the picture. It’ll begin to warm up again early this weekend, but there are signs for a strong cold frontal passage by the early part of next week that may be accompanied by snow shower activity.

Video

httpv://youtu.be/oG7qIk6rP3U

11:15 AM | Growing sunspot region captured on cool video

Discussion

The sun has been somewhat more active in recent weeks with several sunspot regions and NASA’s Solar and Heliospheric Observatory has just recently captured an interesting expansion of the region officially called AR1619 over a 24-hour period (see video). AR1619 was barely visible at the beginning of the weekend, but it has now blossomed into a large region that is more than three times as wide as the Earth. So far the growing sunspot region has been rather quiet, but sometimes expansion and fast-changing magnetic fields indicate that an eruption may soon take place. AR1619 is now in a position that faces the Earth directly so any near-term eruption could have an impact on the Earth’s upper atmosphere. Additionally, another large sunspot region known as AR1618 is also rotating into a position that faces the Earth directly so this area will also be monitored over the next couple of days here at thesiweather.com.

Video

httpv://youtu.be/Bq61Oh8rNIA

7:00 AM | Back to the 70's by later this week

6-Day Forecast

Today

Mainly sunny, breezy, cool, highs in the mid 60’s

Tonight

Mostly clear, cool, some fog possible late, lows in the mid 50’s

Wednesday

Some fog possible early then becoming mostly sunny, cool, mid 60’s

Wednesday Night

Mostly cloudy, cool, fog possible late, mid 50’s

Thursday

Fog, clouds early then becoming mostly sunny, warmer, upper 60’s

Friday

Partly sunny, mild, low-to-mid 70’s

Saturday

Mostly sunny, warm, mid 70’s

Sunday

Mostly sunny, warm, low 70’s

Discussion

Temperatures will be slightly below normal into mid-week, but then above normal readings are likely at the end of the week as offshore flow develops.

Video

httpv://youtu.be/Zkb2gw1pPvU

7:00 AM | Nice weather pattern continues

6-Day Forecast

Today

Mostly sunny, mild, highs in the mid 60’s

Tonight

Mostly clear, cold, lows in the upper 30’s

Wednesday

Mostly sunny, warm, mid-to-upper 60’s

Wednesday Night

Mostly clear, chilly, mid 30’s

Thursday

Mainly sunny, not as warm, mid 50’s

Friday

Partly sunny, chilly, low-to-mid 50’s

Saturday

Mostly sunny, milder, low 60’s

Sunday

Mostly sunny, mild, upper 50’s

Discussion

An upper level ridge over the central Plains and an upper level trough over the Pacific Northwest will combine to produce a southwest flow of air over the Colorado Rockies into the mid-week time period. Highs will actually climb back to the 60’s on both days and there is still no precipitation in sight as our dry weather pattern continues.

Video

httpv://youtu.be/Zkb2gw1pPvU

7:00 AM | Dry pattern continues with warm temperatures

6-Day Forecast

Today

Mostly sunny, warm, highs in the low 60’s

Tonight

Mostly clear, cold, lows in the low 30’s

Tuesday

Mostly sunny, warm, mid 60’s

Tuesday Night

Mostly clear, chilly, low 30’s

Wednesday

Mainly sunny, warm, upper 60's

Thursday

Partly sunny, cooler, mid-to-upper 50’s

Friday

Mostly sunny, cool, low 50’s

Saturday

Mostly sunny, milder, low 60's

Discussion

A weak disturbance approaches the region today, but as has been the case recently, it is moisture-starved. As a result, our dry stretch of weather will continue right through much of the week and our temperatures will remain on the warm side for this time of year through mid-week with a little bit of a cool down for Turkey Day.

Video

httpv://youtu.be/CO2PC2s7XTw

7:00 AM | Unsettled weekend weather gives way to a warmer and drier week

6-Day Forecast

Today

Mostly cloudy, breezy, cool, highs in the low 60’s

Tonight

Mostly clear early, clouds and fog late, cool, lows in the mid 50’s

Tuesday

Clouds and fog early then becoming partly sunny, cool, mid 60’s

Tuesday Night

Mostly cloudy, cool, fog possible late, mid 50’s

Wednesday

Mostly sunny, warmer, upper 60’s

Thursday

Partly sunny, mild, upper 60’s

Friday

Mostly sunny, warm, low-to-mid 70’s

Saturday

Mostly sunny, warm, low-to-mid 70’s

Discussion

After an unsettled weekend, the weather will turn warmer and drier this week as high pressure builds into the region. By the end of the week, high temperatures are likely to surpass the 70 degree mark.

Video

httpv://youtu.be/CO2PC2s7XTw

11:30 AM | Leonid meteor shower peaks in the pre-dawn hours with excellent viewing conditions

Discussion

It is time for the annual mid-November Leonid meteor shower which peaks before dawn (2-6am) as the Earth passes through the debris left behind by the comet Tempel-Tuttle. This comet, like all others, is slowly disintegrating and over the centuries its remains have spread all along its orbit to form a moving river of rubble millions of miles wide and hundreds of millions of miles long. This year has the advantage of a lunar phase (1st quarter) that should not interfere with sky gazers in the late night time period; however, it is not expected that the show will be nearly as good as it was from 1998 to 2002 when the comet was in closer proximity to the Earth. The rate of meteors during those great viewing years of 1998 to 2002 ranged from a few hundred to a few thousand per hour whereas the expectation for tonight’s show is on the order of around 10-15 meteors per hour. The particles are traveling at 45 miles per second with respect to the Earth and when one of them strikes the Earth’s upper atmosphere about 50 to 80 miles up, friction vaporizes it into a quick, white-hot streak. The vast majority of Leonids are not strong enough to survive the atmospheric flight and as such they cannot reach the Earth’s surface. The meteors will appear as if they are originating from the constellation Leo (hence the name) - to find Leo look to the eastern sky and then look up. As far as viewing conditions are concerned, they look excellent in the Mid-Atlantic region for the pre-dawn hours with mostly clear skies expected, but it'll be downright cold.

One other note, there actually will be a 2nd chance at viewing this meteor shower during the early morning hours of Tuesday, the 20th, when it peaks for a second time. A second peak is somewhat unusual, but is possible as the Earth passes through a second debris shield left by the comet. In fact, the second peak may produce a slightly higher number of meteors per hour in the pre-dawn hours of next Tuesday.

7:00 AM | Cool and unsettled right through the weekend; Leonid meteor shower in the pre-dawn hours

6-Day Forecast

Today

Mostly cloudy, cool, showers possible, highs in the low 60’s

Tonight

Mostly cloudy, cool, showers likely, lows in the mid-to-upper 50’s

Saturday

Mostly cloudy, cool, showers likely, low 60’s

Saturday Night

Mostly cloudy, cool, showers still possible, mid 50’s

Sunday

Partly sunny, showers still possible, cool, low 60’s

Monday

Partly sunny, cool, low 60’s

Tuesday

Mostly sunny, cool, mid 60’s

Wednesday

Mainly sunny, cool, mid 60’s

Discussion

A series of storms will affect the Pacific coast over the next few days and rain is likely to expand into Southern California to close out the work week. The higher elevations of eastern and northern California will receive accumulating snows from this system. Temperatures will hold at below normal levels right through the weekend and into the early part of next week. One final note - the annual Leonid meteor shower will peak in the pre-dawn hours (2-6am) with favorable viewing conditions expected.

Video

httpv://youtu.be/fhvnP2fou9w