7:00 AM | Milder, but somewhat unsettled for the next few days; strong cold frontal passage comes late Friday night

6-Day Forecast

Today

More clouds than sun, milder, highs in the low-to-mid 70’s

Tonight

Mostly cloudy, cool, chance for a couple of showers, maybe a thunderstorm, lows in the upper 50’s

Wednesday

Mostly cloudy, very mild, chance for a few showers and maybe a thunderstorm, upper 70’s

Wednesday Night

Mostly cloudy, mild, can’t rule out a couple of showers, upper 50’s

Thursday

Mostly cloudy, breezy, very mild, chance for a few showers, maybe a thunderstorm, upper 70’s

Friday

Mostly cloudy, windy, mild, chance for showers and thunderstorms late in the day and at night, mid-to-upper 70’s

Saturday

Mostly cloudy, windy, cooler, showers possible in the morning, near 60

Sunday

Mostly sunny, chilly, upper 50’s

Discussion

A weak frontal system will cause somewhat unsettled weather around here for the next few days and then a strong cold front will arrive at the east coast late Friday night. While there can be an occasional shower or thunderstorm over the next couple of days associated with the weak frontal system, a more organized and significant band of showers and thunderstorms is likely to arrive Friday night with the strong west-to-east moving cold front. That front may linger for a bit on Saturday morning and then it will usher in noticeably cooler air for the rest of the weekend, and the overall weather pattern will likely stay on the cool side for much of next week.

Elsewhere, winter hangs on out west. Denver received more significant accumulating snow yesterday and that was just round one for that area as another snowstorm is headed there for tonight and Wednesday with an additional half of foot or more possible. In fact, the entire region from the southern Rockies to the Northern Plains will get pounded once again with significant springtime snow accumulations over the next 48 hours or so. On Sunday, Bismarck, ND received its biggest snowstorm ever, 17.3 inches, and the New York Mets have been postponed on consecutive days - first in Minneapolis on Sunday due to snow and ice and then yesterday in Denver due to ankle-deep snow, and it doesn't look too favorable there for today or tomorrow with more wintry conditions expected.

Video

httpv://youtu.be/Mhb3L64LDu0

12:10 PM | Weather and the Titanic disaster 101 years ago today

Discussion

As we arrive at the 101st anniversary of the sinking of the RMS Titanic (April 14-15, 1912), I thought I’d revisit the overall weather pattern that played a key role in the tragedy. By studying weather maps and written records from that time period, some definitive conclusions can be drawn about the weather during the trip across the Atlantic, and there are also some interesting new theories. First off, the voyage started off with fine weather for the first three days including light winds and mild temperatures. However, by the last night of the fateful trip, a strong cold front sweeping off the east coast of Canada, moved through that part of the North Atlantic and the temperatures dropped from the lows 40’s to near freezing in just a few hours as the ship entered an area of Arctic high pressure (actual US Weather Bureau surface weather map from April 15th, 1912 on the Facebook page). Skies were relatively clear and the stars could be seen rather easily as the moon was in a “new moon” phase. While the seas were relatively calm, a NW flow of air developed behind the front and actually steered a giant ice field towards the ship that night. Finally, at about 20 minutes before midnight, the ship hit an iceberg that has been estimated as possibly weighing up to 300,000 tons, and the ship’s hull was torn open. It then took less than three hours from that point on for the Titanic to sink and there were, of course, too few life rafts for all of the people on board. The temperature of the water was estimated to be as low as 28 degrees – even lower than the conventional 32 degree freezing point as salt helped to lower its freezing point.

Recently, there have been more unconventional theories about nature’s role in the sinking of the Titanic. For example, a recent study suggests that the nearness of the Earth to the Moon and Sun – a proximity not matched in more than 1,000 years – resulted in record tides that help explain why the Titanic encountered so much ice. Specifically, the nearness of the Earth to the Sun and Moon enhanced their gravitational pulls on the ocean and produced record tides in the weeks before the disaster. It is suggested that these record high tides refloated masses of icebergs traditionally stuck along the coastlines of Labrador and Newfoundland and sent them adrift into the North Atlantic shipping lanes.

Additionally, a second theory regarding nature’s role in the disaster contends that the icy waters created ideal conditions for an unusual cold water type mirage called a superior mirage. A superior mirage would act to bend light rays downward resulting in warped images which may have confused nearby ships trying to help with rescue efforts and could explain why icebergs may have been temporarily hidden from the lookouts on the ship that night. A superior mirage occurs when warmer, less dense air sits atop colder, more dense air – a condition known as a temperature inversion. This is the opposite of the more familiar “desert mirage” atmospheric scenario in which case the surface is very hot causing light to bend upward towards the sky which then shows the sky on the ground that looks like water. One piece of evidence that a temperature inversion existed that fateful night has to do with the fact that some of the life boat survivors recalled seeing a smoke plume “flatten” as it rose from the Titanic to a certain height. This is typical in an inversion since as the smoke plume reaches a stable layer in the atmosphere it tends to “flatten” out rather than continuing to rise. The superior mirage theory suggests that the freighter SS Californian was unable to identify the Titanic on the moonless night because even though the Titanic sailed into the Californian's view, it appeared to the crew on that ship to be too small to be the great ocean liner. Also, the crew on the SS Californian testified later that they weren’t quite sure what they were seeing on the horizon when the Titanic was shooting distress rockets into the air. The Titanic’s rockets appeared quite low in the sky – perhaps as a result of a superior mirage – not at the higher heights that the crew would have expected if indeed they were distress signals. Finally, the superior mirage may have also disrupted signals sent by the Titanic to the SS Californian with a powerful electric Morse lamp as the crew later reported that the carefully timed flashes arrived distorted and jumbled. History will never know exactly what events and conditions precipitated the Titanic disaster, but the mirage theory is backed by some eyewitness accounts and raw meteorological data.

Finally, in a strange twist to this story, the SS Californian actually suffered a similar fate as the Titanic as it was sunk during World War 1 (November 9th, 1915) by a German submarine in the eastern Mediterranean Sea. One person lost their life and the ship has never been found.

7:00 AM | Cool and damp today; milder by mid-week, but a strong cold front will end the work week

6-Day Forecast

Today

Overcast skies this morning with occasional showers; otherwise, remaining mostly cloudy, highs in the low-to-mid 60's

Tonight

Mostly cloudy, cool, lows in the low 50’s

Tuesday

Mostly cloudy, milder, chance for a shower, mid 70’s

Tuesday Night

Mostly cloudy, cool, mid 50’s

Wednesday

Partly sunny, very mild, chance for a shower or thunderstorm, upper 70’s

Thursday

Mostly cloudy, breezy, very mild, chance for showers, maybe a thunderstorm, near 80

Friday

Mostly cloudy, windy, mild, PM showers likely and possible thunderstorms, mid 70’s

Saturday

Mostly cloudy, windy and cooler, chance for a few showers, near 60

Discussion

After a rather seasonal weekend, it’ll turn milder by mid-week and the second half of the week looks well above normal temperature-wise. A weak frontal system could cause a few showers around here each day through Thursday and then a more important strong cold front will approach from the west at the end of the work week. That front will likely bring some shower and thunderstorm activity to the Mid-Atlantic region later Friday and it’ll turn noticeably cooler behind it this weekend. In fact, the overall weather pattern looks like it’ll be cooler-than-normal next week following this end-of-the-week frontal passage.

Elsewhere, winter-like weather continues today across much of the country from the Rockies to the Northern Plains and another snowstorm is destined to hit places that got hit last week with accumulating snow likely in the zone between Denver, CO and Minneapolis, MN over the next few days.

Video

httpv://youtu.be/vWVgQdxSdYY

10:00 AM | Incoming solar storm...possible northern lights tonight

Discussion

Several sunspot regions have emerged in recent days during the current solar cycle (#24) and one such region, officially called AR1719, erupted on Thursday morning resulting in a coronal mass ejection (CME) directed towards the Earth. That CME is expected to reach the Earth’s upper atmosphere this evening as it is traveling some 600 miles per second. As a result, northern lights are quite possible across the northern tier of states Saturday night – perhaps as far south as Pennsylvania, New Jersey and Delaware where viewing conditions should be quite good. The eruption on the sun Thursday morning was officially classified as an M6-class eruption. Solar flares create auroras when radiation from the sun reaches Earth and interacts with charged protons in our atmosphere. The effects are greater at the magnetic poles and weaken as they move south from the Arctic or north of the Antarctic. The CME emerged from the circled area on the sun early Thursday morning (image on Facebook page).

7:00 AM | A decent weekend coming following today's cold front generated heavy rainfall

6-Day Forecast

Today

Cloudy, periods of rain and thunderstorms likely during the morning hours, some of the rain will be heavy, highs in the low-to-mid 70’s

Tonight

Becoming partly cloudy, chilly, lows in the upper 40’s

Saturday

Mostly sunny, breezy and seasonably cool, highs near 65

Saturday Night

Partly cloudy, chilly, low 40’s

Sunday

Mostly sunny, seasonably cool, mid 60’s

Monday

Mostly sunny, milder, mid 70’s

Tuesday

Mostly cloudy, mild, chance for a couple of showers, upper 70’s

Wednesday

Mostly cloudy, mild, chance for a few showers and thunderstorms at night, upper 70’s

Discussion

A strong cold front is heading for the east coast and it will cause periods of rain and thunderstorms in the DC metro region this morning and some of the rain will fall heavily at times. The soaking and beneficial rains of today will make for a "green explosion" this weekend as lawns will suddenly take on a nice dark green appearance. The front will slide off the east coast tonight and drier air will filter into the region just in time for the weekend. Both weekend days should feature some sunshine and seasonably cool conditions with highs not far from 65 degrees. It’ll turn milder early next week, but a couple of fronts could bring us a couple of showers by mid-week.

By late next week, it looks like there will be another strong cold front closing in on the east coast and it will likely generate another significant rain event for the East - perhaps including more strong thunderstorms. Following that end-of-the-week frontal passage, the overall weather pattern could turn chilly again in the East. Also next week, there will be another snowstorm for the places that got hit this week (e.g. Denver, Minneapolis).

Video

httpv://youtu.be/JrBUXy7oQjk

7:00 AM | We'll try to squeeze out one more 80 degree day before showers and thunderstorms move in later tonight and on Friday with strong cold front

6-Day Forecast

Today

Partly sunny, a little bit cooler than yesterday, but still quite warm, light E-NE winds, highs near 80 degrees

Tonight

Mostly cloudy, showers and thunderstorms likely, some of the rain will be heavy, lows in the low-to-mid 50’s

Friday

Mostly cloudy, showers and thunderstorms likely, some of the rain will be heavy, mid 70’s

Friday Night

Becoming partly cloudy, chilly, mid-to-upper 40’s

Saturday

Mostly sunny, breezy, seasonably cool, mid 60’s

Sunday

Mostly sunny, seasonal, mid-to-upper 60's

Monday

Mostly sunny, milder, mid 70’s

Tuesday

Partly sunny, warm, chance for showers and thunderstorms late in the day, upper 70’s

Discussion

A back door cold front has dropped southward overnight through the Mid-Atlantic region and this has generated a light ocean flow of air around here. Given the still quite cold ocean temperatures, this will make it slightly cooler today compared to yesterday's record-breaking heat (91 degrees at Reagan National), but we’ll still likely come close to 80 degrees. Farther north, the ocean flow of air will have a much more dramatic effect on temperatures as Philly will likely hold in the 60’s, NYC metro region in the 50’s, and Boston in the 40's.

A more conventional west-to-east moving cold front will approach the region later tonight and Friday bringing with it periods of rain and perhaps a few strong thunderstorms. Once the front sweeps off the east coast by tomorrow night, drier air will return to the region and the weekend is shaping up to be pretty decent with highs in the 60's on both days. It'll turn warmer early next week with highs back up in the 70's on Monday and Tuesday.

Video

httpv://youtu.be/jdi_andtRF0

3:00 PM | Shower and strong thunderstorm threat this evening from Philly to NYC

Discussion

The stage is being set in the atmosphere for some potential fireworks this evening across the I-95 corridor from Philly to New York City. An increasingly cool air mass is now sliding down through New England into southern New York (back door cold front) while simultaneously, record or near record-breaking warmth has settled in across southern Pennsylvania, northern Maryland, Virginia and the DC metro region. In fact, temperatures today have climbed to near 90 degrees in the DC metro region and into the middle 80’s around Philly, but have dropped into the low 50’s up the coastline in Boston, MA. Meanwhile, an impressive band of showers and strong thunderstorms has fired up this afternoon across eastern Ohio and western Pennsylvania, and it is charging eastward right into this clash of air masses along the I-95 strip. Additional showers and thunderstorms are lining up farther to the west across the Ohio Valley and they too will likely affect the I-95 corridor in the overnight hours. The end result will be numerous showers and strong thunderstorms between about 6pm and midnight in the region from Philly to NYC and some of the rain will fall heavily at times. Also, hail is a possibility with some of the strong storms as well as frequent lightning and wind gusts to 50 mph or so.

The cool air mass now in place across New England will continue to press to the southwest overnight, and it’ll be noticeably cooler tomorrow in NYC and Philly as compared to today, but the DC metro region will likely have a minimal impact by this back door cold front and should still reach the 80 degree mark for highs tomorrow afternoon. More rain and thunderstorms threaten the entire Mid-Atlantic region later tomorrow night and Friday from a more conventional west-to-east moving cold front and some of that rain is likely to be heavy.

7:00 AM | Two more days with very warm conditions, but transition back to more seasonal conditions may bring some heavy rain and strong thunderstorms to the region later in the week

6-Day Forecast

Today

Mostly sunny, very warm, highs in the mid-to-upper 80’s

Tonight

Mostly cloudy, mild, lows in the low 60’s

Thursday

Partly sunny, still very warm, chance for showers and thunderstorms at the end of the day, mid 80’s

Thursday Night

Mostly cloudy, mild, showers likely and maybe a couple of thunderstorms, some of the rain can be heavy at times, upper 50’s

Friday

Mostly cloudy, cooler, periods of rain and maybe a few thunderstorms, some of the morning rain can be heavy at times, low 70’s

Saturday

Mostly sunny, breezy, cooler, low-to-mid 60’s

Sunday

Mostly sunny, cool, low 60’s

Monday

Partly sunny, a bit milder, maybe a late day shower or thunderstorm, low-to-mid 70’s

Discussion

An active and complicated weather pattern continues today across much of the country ranging from near record warmth in the East to blizzard conditions in the nation’s mid-section and there will be a series of frontal systems to deal with around here between tonight and late Friday. Today will be another very warm day around here with 85+ degrees possible for high temperatures this afternoon along with plenty of sunshine. The middle 80’s are likely again here on Thursday; however, we’ll be watching the dreaded back door cold front which is likely to dramatically cool things down in the NYC metro region, but most likely not this far south. A strong west-to-east moving cold front will then approach the region from the Great Lakes region tomorrow night and Friday, and the transition back to more seasonal conditions by the weekend could be quite a bumpy ride with possible strong thunderstorms and heavy rainfall. This strong cold front will clear out of here by Saturday and sunshine will return, but it’ll be breezy and noticeably cooler.

Video

httpv://youtu.be/Tgls9bxayUc

11:40 AM | Global sea ice update...now running slightly above normal

Discussion

Sea ice occupies about 7% of the surface area of planet Earth and is especially important in polar regions. Even though sea ice is found predominately in polar regions, it does have an influence on global climate as its bright surface reflects much sunlight back into space. The North Pole region is considerably different than the South Pole in that up north there is an ocean (Arctic) that is surrounded by land whereas down south there is land (continent of Antarctica) surrounded by ocean. The Arctic responds much more directly to changes in air and sea-surface temperatures than does Antarctica. Currently, the northern hemisphere sea ice content is below normal while the southern hemisphere is well above normal and the combination of the two has produced a global sea ice content that is now actually slightly above normal.

The below normal trend for northern hemispheric sea ice began in the mid-90’s at which time the Atlantic Ocean entered a warm (positive) phase. Atlantic Ocean sea surface temperatures can be tracked through an index called the Atlantic Multidecadal Oscillation (AMO). Specifically, sea-surface temperatures in the north Atlantic have been running at above normal levels in recent years and this is having an influence on the northern hemisphere sea ice content. Oceanic cycles can last two or three decades and it is quite likely that when the AMO returns to a cold (negative) phase the sea ice in the Arctic region will return to normal or even above normal levels on a consistent basis similar to what happened prior to the mid-90’s. Meanwhile, way down south the sea surface temperatures have been running below normal in recent times in those areas surrounding the continent of Antarctica and this is contributing to the above normal levels of sea ice in that part of the world.

Video

httpv://youtu.be/CxRFJYy_yk0

7:00 AM | From spring to summer for the next few days; turns much cooler again by the weekend

6-Day Forecast

Today

Mostly sunny, very warm, highs in the low-to-mid 80’s

Tonight

Mostly cloudy, mild, lows near 60 degrees

Wednesday

Mostly sunny, very warm, mid 80’s

Wednesday Night

Mostly cloudy, mild, low 60’s

Thursday

Partly sunny, warm, chance for showers and thunderstorms late in the day and at night, low-to-mid 80’s

Friday

Mostly cloudy, cooler, chance for showers and thunderstorms, near 70

Saturday

Mostly sunny, breezy, cool, low 60's

Sunday

Partly sunny, cool, low 60's

Discussion

The weather in the DC metro region will produce a touch of summer today and tomorrow as temperatures climb past 80 degrees on both days. Warm weather continues on Thursday as well with temperatures moving to 80+ degrees once again as a strong cold front approaches the region from the Midwest. That frontal system will bring us increasing clouds on Thursday and the chance for late day and nighttime showers and thunderstorms. Much cooler air will move in behind the front on Friday and there can be some steady rain accompanying the cool down to close out the work week. Cooler weather will then continue this weekend, but skies should clear on Saturday allowing for sunshine although there will be a stiff breeze. Elsewhere, an active weather pattern continues today across much of the country with a springtime snowstorm from the southern Rockies to the Northern Plains, and a severe weather threat across the central Plains from Texas to Iowa.

Video

httpv://youtu.be/e1FGlK8TWPg