7:00 AM | More nice weather in the Mid-Atlantic region as we begin a new season

6-Day Forecast

Today

A mix of clouds and sun, cool, highs near 70 degrees

Tonight

Mostly clear, quite chilly, lows by morning in the mid 40's

Tuesday

Mostly sunny, cool, low 70’s

Tuesday Night

Mostly clear, chilly, low 50’s

Wednesday

Mostly sunny, pleasant, mid 70’s

Thursday

Mostly sunny, a bit milder, mid-to-upper 70’s

Friday

Mostly sunny, nice, mid 70’s

Saturday

Mostly sunny, comfortable, mid 70’s

Discussion

The strong cool frontal system that passed through the area this weekend has ushered in another Canadian-born high pressure system and cool air mass for the Mid-Atlantic region. Despite plenty of sunshine for the next couple of days, temperatures will hold at below normal levels for afternoon highs (normal high for DCA is 78 degrees). Elsewhere, there is plenty of moisture around the Gulf of Mexico region, but it appears that this will stay well to our south over the next few days.

Video

httpv://youtu.be/QIuk5x2YDiM

10:00 AM | The Great New England Hurricane of 1938

Track of 1938 hurricane (National Weather Service)

Discussion

Today marks the 75th anniversary of The Great New England Hurricane of 1938 which is also known as The Long Island Express and the Yankee Clipper. With no warning, the powerful category 3 hurricane (previously a category 5) slammed into Long Island and southern New England causing approximately 700 deaths and massive devastation to coastal cities and became the most destructive storm to strike the region in the 20th century. Little media attention was given to the powerful hurricane while it was out at sea as Europe was on the brink of war. There was no advanced meteorological technology such as radar or satellite imagery to warn of the storm’s approach.

The storm began on September 10th near the Cape Verde Islands in the eastern Atlantic. About a week later, the captain of a Brazilian freighter sighted the storm near Puerto Rico and radioed a warning to the US Weather Bureau and it was expected that the storm would make landfall in south Florida where preparations frantically began. By September 19th, however, the storm suddenly changed direction and began moving north, parallel to the eastern seaboard. It had been many decades since New England had been hit by a substantial hurricane and few believed it could happen again. The storm picked up tremendous speed as it moved to the north following a track over the warm Gulf waters.

By the time the fast-moving storm approached Long Island, it was simply too late for a warning. In the middle of the afternoon on September 21st, the hurricane made landfall along the south shore of Long Island right around high tide when there was nearly a new moon (highest astronomical tide of the year). To make matters worse, this part of the country had just been through a long rainy period which saturated grounds before the arrival of this great storm. Waves as high as 40+ feet swallowed up coastal homes and homes that survived the storm surge succumbed to the damaging winds that reached 111-129 mph (lower to the west and higher to the east). By late afternoon, the hurricane raced northward at an amazing 60-70 mph crossing the Long Island Sound and reaching Connecticut. The storm surge of 14-18 feet above normal tide level inundated parts of Long Island and later the southern New England coastline. The waters in Providence harbor rapidly submerged the downtown area of Rhode Island’s capital under more than 13 feet of water and many people were swept away. The accelerating hurricane then continued northward at tremendous speed across Massachusetts generating great flooding in its path. In Milton, a town south of Boston, the Blue Hill Observatory recorded one of the highest wind gusts in history at an incredible 186 mph. Boston was hit hard and “Old Ironsides” – the historic ship USS Constitution – was torn from its moorings in Boston Navy Yard and suffered slight damage. Hundreds of other ships were not so lucky being completely demolished. The hurricane lost intensity as it passed over northern New England, but was still strong enough to cause widespread damage in Canada later that evening before finally dissipating over southeastern Canada later that night. All told, approximately 700 people were killed by the hurricane, 600 of them in Long Island and southern New England, 9000 homes and buildings were destroyed and 3000 ships were sunk or wrecked. It remains the most powerful and deadliest hurricane in recent New England history, eclipsed in landfall intensity perhaps only by the Great Colonial Hurricane of 1635 - the one storm by which all other storms are measured.

Photo of Battery Park on the southern tip of Manhattan during the 1938 storm (National Weather Service)

In terms of weather forecasting for this storm, while the US Weather Bureau did not predict a hurricane landfall, that decision was not without controversy as a junior forecaster named Charlie Pierce believed the storm would curve into Long Island and southern New England due to blocking high pressure to the northeast and trough of low pressure which would guide the storm inland in his opinion. Mr. Pierce was overruled by the chief forecaster, Charles Mitchell. Shortly thereafter, Charles Mitchell resigned and Charlie Pierce was promoted.

Facts of the 1938 Hurricane (Francis, 1998) • Peak Steady Winds - 121 mph • Peak Gust - 186 mph at Blue Hill Observatory, MA. • Lowest Pressure - 27.94 in (946.2 mb) at Bellport, NY • Peak Storm Surge - 17 ft. above normal high tide (RI) • Peak Wave Heights - 50 ft. at Gloucester, MA • Deaths - 700 (600 in New England) • Homeless - 63,000 • Homes, Buildings Destroyed - 8,900 • Boats Lost - 3,300 • Trees Destroyed - 2 Billion (approx.) • Cost - $620 million (1938)

Surface weather map, 9 a.m., September 21, 1938 (National Weather Service)

11:15 AM | Super Typhoon Usagi threatens Taiwan, Philippines, southern China, Hong Kong

[Colorized infrared satellite image of Usagi from early Friday; courtesy NOAA]

Discussion

The strongest tropical system of the year, Super Typhoon Usagi, is currently barreling through the western Pacific Ocean headed for the Luzon Strait which lies between Taiwan and the Philippines. Usagi intensified rapidly between early Wednesday and midday Thursday reaching “super typhoon” status which is equivalent to a strong category 4 or 5 hurricane in the Atlantic Basin with sustained winds of at least 150 mph. Using satellite wind analysis, the central pressure is estimated to have bottomed out near an impressive 882 millibars (26.05 inches) before some weakening in the last several hours. Usagi is expected to weaken slightly over the next 24 hours as it passes south of Taiwan due to some interaction with its mountainous terrain, but it will remain a serious threat to southern China and the densely populated island of Hong Kong, which is often battered by typhoons - perhaps reaching that location by early Sunday. The lack of “hurricane hunters” in the region prevents more exact measurements as to the strength of the storm.

7:00 AM | Strong front to bring rain to the region this weekend and some of it can be heavy late tomorrow

6-Day Forecast

Today

Some patchy fog possible early; otherwise, mostly sunny skies, warm, highs near 80 degrees

Tonight

Partly cloudy, mild, some patchy fog possible late, lows by morning near 60 degrees

Saturday

Increasing clouds, warm, more humid, mid-to-late afternoon showers and possibly a thunderstorm or two, near 80

Saturday Night

Evening showers and possibly a thunderstorm or two, some of the rain can be heavy, low 60’s

Sunday

Mostly cloudy early then partly sunny, cooler, less humid, breezy, mid 70’s

Monday

Mostly sunny, cool, low-to-mid 70’s

Tuesday

Mostly sunny, cool, mid 70’s

Wednesday

Partly sunny, comfortable, mid-to-upper 70’s

Discussion

High pressure off the Northeast US coast will open the door for some changes around here as milder air gets pumped into the region and a cool front closes in this weekend from the Midwest. Temperatures today will rise to near the 80 degree mark and humidity will become a bit more noticeable by tomorrow in the southwest flow of air on the backside of the high pressure system. The next front will generate rain and possible thunderstorms around here from later tomorrow afternoon through tomorrow evening and some of the rain will be heavy at times. Sunday will be cooler and turn less humid with early morning clouds giving way to sunshine and afternoon highs not far from 75 degrees. Nice and cool weather will continue in the Mid-Atlantic region during the early part of next week.

Video

httpv://youtu.be/n30GEKQ-HvQ

1:45 PM | An update on Comet ISON - still expected to be visible to the naked eye in late November

(April 2013 image of Comet ISON through Hubble telescope, courtesy NASA)

Discussion

Comet ISON was first spotted in September 2012 by scientists working with the International Scientific Optical Network (hence its name ISON) and it should become visible to the naked eye in the northern hemisphere in late November. As to how bright the comet will be at the end of the year, it is still somewhat unknown. ISON was once expected to set records for brightness and was dubbed the “comet of the century”, but astronomers now believe it won’t be quite as brilliant as originally thought and it is already dimmer than expected. A comet’s brightness depends not only on how close it passes to Earth and the sun, but also on its size and composition which makes predictions rather tricky.

For now, ISON can be seen in the northern hemisphere through telescopes – a faint smudge in the constellation of Cancer about 183 million miles from the sun. ISON is currently speeding through the cosmos at around 67,000 mph and is expected to accelerate to about 844,000 mph as it swings around the sun. By late November, ISON is expected to move to near 700,000 miles above the sun’s surface. Around this time and into December, astronomers expect that ISON will become visible to the naked eye low in the eastern sky, but it does not look like it will reach the brightness of the full moon as originally hoped. The last truly great comet viewable in the northern hemisphere was Hale-Bopp, which was first spotted in 1995 and remained visible for a record 18 months.

7:00 AM | Showers this weekend from next cool frontal system centered around Saturday night and some of the rain can be heavy

6-Day Forecast

Today

Mostly sunny, pleasant, highs in the mid-to-upper 70’s

Tonight

Partly cloudy, cool, some patchy fog late, lows by morning in the upper 50’s

Friday

Some patchy fog early; otherwise, mostly sunny skies, warm, near 80

Friday Night

Partly cloudy, mild, some patchy fog late, near 60

Saturday

Partly sunny, warm, humid, mid-to-late afternoon and nighttime showers likely and possibly a thunderstorm or two, near 80

Sunday

Mostly cloudy, a bit cooler, chance for a shower or thunderstorm, mid-to-upper 70’s

Monday

Partly sunny, cool, low-to-mid 70’s

Tuesday

Partly sunny, cool, low-to-mid 70’s

Discussion

High pressure sliding off the Mid-Atlantic coast will pump in milder air over the next couple of days and open the door for a cool frontal system to approach the region from the middle of the country. Temperatures today will climb into the comfortable upper 70’s and conditions may be favorable by late tonight for patchy fog to form in some suburban locations. Once that fog burns off tomorrow morning, skies should clear and temperatures will head towards the 80 degree mark. Saturday will start off dry, but showers and possible thunderstorms are likely later Saturday and Saturday night as the front closes in on the region. The front moves through on Sunday, but another shower or thunderstorm is possible as we close out the weekend. It'll turn slightly cooler following the frontal passage for the early part of next week and we'll be watching an area of moisture in the Southeast US that should slide off the coast before ever reaching this far north.

Video

httpv://youtu.be/eqLjbUG58IM

12:00 PM | Potential east coast storm early next week with tropical connections

Discussion

There is potential for an east coast storm early next week that would have tropical connections and possible significant rains for the Mid-Atlantic region. Tropical moisture is in abundance today from the eastern Pacific Ocean to the western Caribbean Sea and signs are that this may consolidate into an area of low pressure this weekend over the Gulf of Mexico and then ride up the east coast early next week. This copious tropical moisture is associated with three different tropical systems: Tropical Depression Manuel along the west coast of Mexico, the remains of Hurricane Ingrid in eastern Mexico, and a tropical disturbance in the western Caribbean/Yucatan Peninsula region which could become Tropical Storm Jerry.

Last night's computer forecast models tend to differ somewhat for a potential east coast storm. The 00Z GFS model (NOAA) does bring a soaking storm into the Southeast US early next week, but it then shifts it off the coast in time to spare the I-95 corridor between DC and NYC with much wind and rain. The 00Z European computer forecast model, however, brings significant rainfall to the Mid-Atlantic region and it often performs better than the GFS model in the medium range with respect to coastal storms. The difference between the two models appears to be in the handling of the upper level features as the GFS has a less-impressive (but still noticeable) “open” upper level wave early next week whereas the European has a distinct healthy-looking “closed” wave leading to a stronger surface wave that is closer to the Mid-Atlantic coastline (upper level forecast maps below). Stay tuned; morning video focuses on this possible scenario.

7:00 AM | Chilly start to the day and a pleasant finish; weekend cool front to bring showers to the region; potential east coast storm early next week

6-Day Forecast

Today

Sunny, chilly start, pleasant afternoon, highs in the low 70’s

Tonight

Mostly clear, chilly, patchy fog possible late, lows by morning in the low-to-mid 50’s

Thursday

Mostly sunny, comfortable, upper 70’s

Thursday Night

Partly cloudy, cool, patchy fog late, upper 50’s

Friday

Patchy fog early then becoming mostly sunny, seasonably warm, near 80

Saturday

Partly sunny, seasonably warm, chance for showers possibly a thunderstorm late in the day or at night, near 80

Sunday

Mostly cloudy, a bit cooler, chance for showers and possible thunderstorms, mid 70’s

Monday

Mostly cloudy, cool, some rain possible, low-to-mid 70’s

Discussion

Today will be another day with plenty of sunshine and below normal temperatures with afternoon highs reaching the low 70's after a chilly start to the day. Strong and widespread high pressure continues to dominate the weather scene in the northeastern part of the country and it will do so for another few days. As the high slips off the east coast tomorrow, warmer air will advance this way and high temperatures will climb to 80 degrees by the end of the week. Fog will become more of an issue as we progress through late September and October given the increasing length of the nights and there can be some patchy fog late tonight/early tomorrow in suburban locations and again late tomorrow night/early Friday morning.

Looking ahead, a cool front will head to the eastern states this weekend and it is likely to generate showers around here and possibly a thunderstorm later Saturday into Sunday. Beyond that, there is a lot of tropical moisture hanging around the Gulf of Mexico and there are signs that a storm may pull out of the Gulf region early next week and possibly ride up the east coast. If this does happen, it could bring some significant rainfall to the region in the Monday/Tuesday time frame. Stay tuned on that.

Finally, tonight's moon will be full and it is known as the "harvest moon" which is the full moon closest to the autumnal equinox. And, after a week of deep quiet, the sun seems to be waking up with five new sunspots now visible on its Earth-facing side.

Video

httpv://youtu.be/sAT8VtrVdAU

7:00 AM | Unseasonably cool weather as normal highs are still around 80 degrees

6-Day Forecast

Today

Sunny, refreshingly cool, highs near 70 degrees

Tonight

Clear, quite chilly, lows by morning near 50 degrees

Wednesday

Mostly sunny, comfortably cool, low-to-mid 70’s

Wednesday Night

Mostly clear, chilly, low 50’s

Thursday

Mostly sunny, pleasant, upper 70’s

Friday

Patchy fog possible early then becoming mostly sunny, a bit warmer, near 80

Saturday

Partly sunny, seasonably warm, chance for showers and thunderstorms, near 80

Sunday

Partly sunny, cooler, chance for showers, mid 70’s

Discussion

A cool front passed through the region early yesterday and set the stage for more cool weather and today may turn out to be the coolest day of the week with unseasonable highs near 70 degrees this afternoon. Strong high pressure sitting on top of the region this evening will help generate more chilly overnight lows in the 40’s in many suburbs with the expected clear skies and calm conditions. Some moderation in temperatures is expected later this week, but that will only return us to near seasonable levels and another cool frontal passage is possible this weekend.

Video

httpv://youtu.be/jonIiRu6JDw

7:00 AM | Yet another Canadian-born high pressure system to take control of our weather for the next few days with more cool air

6-Day Forecast

Today

Showers likely during the morning and mid-day hours; otherwise, mostly cloudy skies, cool, highs in the low-to-mid 70’s

Tonight

Mostly clear, quite chilly, lows by morning in the low 50’s

Tuesday

Mostly sunny, refreshingly cool, low 70’s

Tuesday Night

Mostly clear, quite chilly, near 50

Wednesday

Mostly sunny, still comfortably cool, low-to-mid 70’s

Thursday

Mostly sunny, pleasantly warm, upper 70's

Friday

Partly sunny, warm, chance for showers and thunderstorms at night, near 80

Saturday

Partly sunny, warm, chance for showers and thunderstorms, near 80

Discussion

A cool front is likely to generate light showers around here during the morning and mid-day hours and then its passage will usher in another cool air mass to the Mid-Atlantic region for the next few days. Temperatures today will stay on the cool side in the low-to-middle 70’s, and then drop to the low 50’s late tonight as this next cool air mass becomes well established in the region. Highs on Tuesday will be confined to the low 70’s despite plenty of sunshine. Some moderation in temperatures is expected by Thursday afternoon, but overall conditions will remain quite comfortable.

Video

httpv://youtu.be/nFY8sIyy_Hc