Labor Day Weekend. For as long as I can remember, it has never been an easy forecast and has rarely featured perfect weather. Last year was really hot, with Saturday through Monday seeing temperatures of 92, 93 and 92 respectively. 2012 recorded 1.64" of rain to start the holiday weekend, 2011 ended the weekend with 1.36" of rain, and 2010 was near perfect, with plenty of sunshine, temperatures in the 80s and low humidity with dew points in the 40s and 50s.
That leads us to this weekend. The forecast has been favoring higher levels of heat and humidity to return to the region this weekend and hanging around for the start of September.
A warm front will be knocking on D.C.'s doorstep Saturday and high pressure will be centered in the northern Atlantic. This will lead to the aforementioned increase in humidity levels, meaning more clouds and dew points back in the mid to upper 60s. At this point, Saturday looks to be the coolest part of the weekend with highs in the mid 80s under partly sunny skies. It may even be mostly cloudy to start the day, but sunshine should filter overhead by midday. Even with the frontal boundary, Saturday should feature the lowest threat for rain, with the highest possibility in the mountains.
By Sunday, the warm front will move north bringing in warmer air overhead. OK, let's call it hot air, as high temperatures are forecast to be in the lower 90s by the afternoon hours (See image above). Combine that with high dew points and energy sliding in from the west and afternoon thunderstorms appear to be a solid bet. Some storms may also be heavy rainmakers, as there will be abundant moisture in the atmosphere.
Below is a look at the forecast precipitable water values for Sunday, which when are this high in the 2 inch range, may mean the potential for some very heavy downpours. Be sure to keep an eye on Doppler Radar this weekend, and if you're out at the pool, find us on your phone!
Monday will have similarities to Sunday, as the heat and high humidity won't be going anywhere fast. Troughing east of the mountains will set up by the afternoon again allowing for storm chances later in the day. Highs Labor Day aren't forecast to be quite as hot, topping out in the upper 80s to near 90 degrees.
Delmarva Beach Forecast
How will the beaches fare this weekend? With the slight easterly component to the wind on Saturday, it may be on the cooler side to start, with highs around 80 degrees under partly sunny skies Saturday.
Sunday and Monday do look pretty nice at the beach. Temperatures should be in the low to mid 80s each day under partly cloudy skies. There is a slight chance for a few showers and storms late in the day, but right now the possibility is only around 20-30%.
The rip current risk should subside by Friday and ocean conditions should calm down through the weekend. Regardless, you may want to double-check with the lifeguard before entering the water if you're not a strong swimmer.
August has been a crazy cool month, but we get one last hurrah from summer as the month ends. So far there have only been two days when the mercury has reached 90 degrees or better in D.C. and none at Dulles. Reagan National is running about a degree below average while Dulles had the 3rd coolest first half of August on record, and the month is ending about 4 degrees below average as of today. However, the tables are turning and we will be close to 90 starting Saturday and continuing at least into the middle of next week. Check out the latest 6-10 forecast showing well above average (85) temps.
Typically as we enter September the temps wane. Days get shorter and shorter with a loss of more than an hour of daylight by month's end. Less heating of the earth means the average temperature drops from 84 at the start of September to ten degrees cooler when it ends.
Two other notables for the first meteorological month of fall... hurricanes and allergens. First we'll talk hurricanes as Cristobal continues to churn in the Atlantic today. Click here for the latest advisory from the National Hurricane Center. A high risk of rip currents continues on the Mid-Atlantic coast. Check out Lauryn's blog on that. September is the peak of hurricane season. More major hurricanes are recorded this month than any other. Conditions so far haven't been that favorable for tropical development with wind shear and coolish temperatures. However, there is still time for that to change. There are a few areas of possible development. One in the Gulf of Mexico and the other in the Caribbean.
Here in the Mid-Atlantic we should always be prepared for a hurricane this time of the year.
September is also a bummer of a month for allergy sufferers. While pollen has been moderate, the peak of ragweed season is here. The first week of September usual has the highest pollen count for ragweed in the D.C. area.
We definitely have been lucky in the tropical storm department for the most of this year along the eastern seaboard (with the exception of Hurricane Arthur in early July which did lead to some flooding). Hurricane Cristobal, which is churning just about 300 miles of Cape Hatteras, North Carolina, Hurricane Cristobal will continue to move north-northeast avoiding the east coast of the United States.
However, areas along the eastern seaboard will still indirectly get in on some of the action of Hurricane Cristobal and beachgoers are already starting to feel the effects.
All along the eastern seaboard, from Florida up through New York and Boston, a moderate to high risk for rip currents are being forecast as well as high surf advisories with large crash waves. Rip currents could occur so frequently that a lot of beachgoers for this last week in August are forbidden to enter the water considering the threat for rip currents is so high that it would be life-threatening to anyone entering the surf. These forecast include local Maryland, Delaware and Virginia beaches.
Heading into Labor Day weekend and with the unfortunate and untimely death of an 18 year old whom drowned Tuesday night in Ocean City, Maryland from getting caught in a rip current, I think it would be great to revisit rip current safety: how to recognize a rip current and how to properly save yourself. These currents can occur along any beach that features breaking waves (including the Great Lakes) and they are unfortunately subject to formation at any time during the day and more likely right before or just after low tide. The swells generated by Hurricane Cristobal and brisk onshore flow are creating the environment for a higher risk of rip currents.
According to the U.S. Lifesaving Association statistics, rip currents cause more than 100 drowning fatalities each year and 80% of all rescues on surf beaches nationwide are rip current related. Now, rip current speeds can vary and although rip currents at any speed are particularly dangerous for weak or non-swimmers, some have even been measured as fast as 8 feet per second-which is faster than an Olympic swimmer can swim! Generally though rip current speeds are typically 1 - 2 feet per second.
So how do these things form and why? Well first what is a rip current? It can be summed up as a fast-moving narrow section of water that travels in the offshore direction. In some cases, the width of the rip current can extend to hundreds of yards.
Now how do these rip currents form? As waves near the shore and heads from deep water to shallow water, they break. As the waves break, they generate currents that flow in both offshore/seaward (away from the coast) and alongshore directions. Currents that flow away from the coast are called rip currents.
Although all beaches are susceptible to rip currents, the shape of the shoreline, the location of jetties, sandbars, groins and piers and the nearshore bottom design or bathymetry can all influence rip current development. Therefore, there are some beaches that are more prone to rip currents due to their topography.
So how to you identify rip currents?
Look for either one or more of these clues:
1. a channel of churning, choppy water
2. an area having a notable difference in water color
3. a line of foam, seaweed or debris moving steadily seaward
4. a break in the incoming wave pattern
Some rip currents can be weak and slow and be little to no threat for experienced swimmers, however, that can all change with a size or intensity of the next incoming wave. A strong wave can causes pulses in the strength of a rip current-so always be aware although most of the time, rip currents are not easily identifiable. *Safety tip - Polarized sunglasses make it easier to see rip currents*
Now on to the next: How do you survive rip currents?
First thing first: if you find yourself caught in a rip current, REMAIN CALM. A rip current is a horizontal current. They do not pull people under water but instead, pull them away from the shore. Most of the deaths that occur from rip currents happen when people are pulled offshore and are unable to keep themselves afloat because they can't swim to shore.
So here are some tips: Once you calm yourself, you can think more clearly so remaining calm is number one!
Secondly, DON'T FIGHT THE CURRENT. Swim out of the current parallel to the beach/shoreline. When you feel that you are out of the current, swim back towards the shore. If you are unable to swim out of the rip current, float or calmly tread water until you feel that you are not being pulled anymore. Don't exert any extra energy. Now, if these tips do not work, draw attention to yourself: face the shore, wave your arms and yell for help.
(Photo courtesy of National Weather Service)
Contact a lifeguard or 911 if needed! Many people drown while trying to save someone else from a rip current. The best thing you can do it throw the victim something that floats and yell instructions on how to escape.
Fog is a subtle weather condition that can quickly become dangerous for commuters, walkers, bikers and runners without advanced warning. It doesn’t come with a bang like a thunderstorm or can be seen slowly piling up like snow, but rather slowly and quietly develops, usually at night, and can cause serious and abrupt visibility problems the following morning.
Fog is typically found in the cooler season because of the longer nights, which allow the temperature to drop to the dew point and condense suspended moisture in the air. Also, stronger storm systems often occur later in the fall (November particularly) which can produce foggy scenarios.
A recent study from the National Weather Service in Blacksburg, Va., showed that nearly 65% of fog events for the Blue Ridge foothills and Piedmont occurred November through February. Only 13% widespread dense fog events happen in the spring and summer.
In most of the fog events studied, a key feature was the position of a strong surface high pressure. High pressure produces sinking air, which results in clear skies and light wind (the perfect recipe for fog). When high pressure is anchored along or off the East Coast, the Mid-Atlantic tends to have foggy nights.
The upcoming pattern this week favors a similar set up where high pressure will be focused across the Mid-Atlantic and southern New England.
The type of fog most common across the Mid-Atlantic from April to August is Radiation Fog. Clear skies and calm wind at night allow temperatures to drop to the dew point. During times when the ground is wet from recent rain or a surplus in precipitation (as it is now across the Washington area), the surface dew point increases, making it easier for the temperature to drop to the dew point before the sun rises.
This often occurs along river valleys or near lakes and bays due to the high moisture content that is able to condense as suspended moisture, resulting in morning fog. Wind tends to be calm in valleys and higher in speed in the mountains, so that is why the Shenandoah Valley (highlighted in the image below) and towns adjacent to the Chesapeake Bay are favored for fog formation as well. This type of fog is usually shallow and lifts quickly following sunrise.
Another way in which fog forms is by means of a warm front. Fall is the time of year when the contrast in temperature in the Northern Hemisphere increases, resulting in stronger storms. The Mid-Atlantic is prone to the influence of warm fronts ahead of low pressures later in the fall season (see image below).
Warm air overrides cooler air at the surface producing widespread thick layer of fog that can linger for many hours. Southeast winds ahead of warm fronts in our region often produce upslope fog. An already moist air mass originating from the Chesapeake Bay and Atlantic Ocean glides up the eastern side of the Blue Ridge (western Frederick and Loudoun County, northern Fauquier County) and the air condenses to form fog just on the eastern flank of the mountain. This often limits visibility on Interstate 70 between Frederick and Hagerstown, for instance.
So, as the daylight shrinks in the coming months, be aware that morning fog will become more common across the Washington area. As always, get your latest 7-day forecast here.
An Air Force Reserve Hurricane Hunter aircraft investigating a disturbance near the southeastern Bahamas determined that the system has become organized enough with a well-defined circulation to be classified Saturday night and as of Sunday Cristobal becomes our third tropical storm of the season.
Latest models continue to have it slowly meander north/northwest bringing torrential rains and gusty winds to the Turks and Caicos as well as the Bahamas through the weekend. After the weekend it would appear that the storm should make more of a shift to the north/northeast but running parallel to the coast of the US. Here is the official track from the National Hurricane Center as of Saturday night.
The bulk of the models keep the storm out to sea which would make for rough surf and increase threat of rip currents. As you can see from the latest spaghetti plot (all models plotted together) a few outlier models want to bring the storm to the US, so we will need to watch this carefully over the coming days - the track it takes and the intensity it attains.
Anyone with interests along the Eastern Seaboard, Florida and even the Gulf Coast should pay close attention to updates into early next week. It is not out of the question that it could shift closer to the US if not directly impact it.
If you like cloudy, muggy and gloomy weather then this week is your week. Fortunately, temperatures will be held at bay, only reaching into the lower to mid-80s for daytime highs Tuesday, Wednesday and Thursday but the humidity will continue to stream into viewing area as the region is wedged between an area of high pressure to the north and an area of high pressure to the southwest (take a peek at the graphic below).
Courtesy of The National Weather Service Baltimore-Washington
A frontal boundary will also continue to be draped across our region and will continue to meander in the vicinity of central Virginia and the D.C. metro area at least through Thursday. That frontal boundary will be the main forcing mechanism for any showers or small thunderstorms that pop up around the region Tuesday afternoon. This means that generally any rain that pops up will be around the stationary front getting caught up in our easterly flow and will preside mainly just south of the Washington D.C. metro area on Tuesday afternoon and evening. Unfortunately, since there is so much moisture and the fact that there is no element that is moving these cells along quickly, are few could contain isolated downpours. Good news is that I don’t anticipate any widespread severe weather for Tuesday evening and into Tuesday night.
The frontal boundary is just to the south of Washington D.C. on Tuesday afternoon, draped across Fredericksburg through Southern Maryland and back to the west around the Eastern West Virginia Panhandle.
If you are headed out to Nats Park tonight, just know it will be a little on the steamy side but I do believe that we will remain dry. Plenty of clouds will stick around through the duration of the game against the Arizona Diamondbacks as temperatures drop through the 70s. There could even be some areas of fog that form while you make your way home from the stadium.
Overnight temperatures on Tuesday will only fall to right around 70 degrees in most locations and warm back up into the mid-80s once again tomorrow. There could be a few peeks of sunshine once again Wednesday but an upper level low, diving out of the northwest, will be headed this way.
A piece of energy out in front of that low will move into the region Wednesday afternoon through Wednesday evening. This means we have a good chance to see some showers and thunderstorms around the region. Most of the activity will die off in the evening hours as we lose our heating from the day but there is a about a 20% chance that a few showers or storms could linger into the late evening hours leading into Thursday.
By Thursday morning, that upper level low (reference the first graphic from the National Weather Service for more information on the upper level low) will be nearing our area, crossing through during Thursday afternoon and Thursday evening bringing us yet another chance of some showers and thunderstorms. This time, there is about at 50% chance of scattered showers and thunderstorms around the region on Thursday.
The best chance for a good soaking rain comes on Thursday but all in all expect less than a 1.00” in total rain accumulation from Tuesday throughThursday night. This will be good because if you have found yourself sniffling a little through the weekend and into the first part of this week, around the D.C. region mold, grasses and weed pollen is all running a little on the elevated side. So it will be good to get some rain to alleviate some of those allergies.
Due to the rain that we received through the first half of August, we are well over our normal averages for rain during the summer (June – August 19th) at Reagan National Airport as well as Baltimore-Washington Airport (in fact, the rain that fell on Tuesday, August 12th put BWI +4.38” over their normal rainfall amount for the summer). Dulles International Airport could still use some rain however, as they are behind a little over 1.50” for rain accumulation for the summer months.
And while we are at it, to be completely honest, I am still not sold on keeping Friday through the weekend dry. I have continued to have it dry in my forecast for the last two days but I believe it is going to be a wait and see game to if this pattern sticks through Friday and into the weekend or to see if high pressure can edge out bringing some more pleasant conditions. Either way, we will keep an eye on it for you and let you know as the picture becomes clearer.
While we have experienced some seriously beautiful weather so far this August we have also had several very chilly mornings in the Mid-Atlantic. When you average the high and low temperatures together, we rank in the top three coolest months of August up to this point at Dulles and Baltimore. Here is a graphic from the National Weather Service that shows our average temperature so far from August 1st through the 15th compared to the averages and records for the month.
Not once did the thermometer at Dulles or BWI reach 90 degrees in August of 2014. 87 was the hottest day of the month at Dulles, VA on the 5th. If we take a look at Reagan National, while it was also cooler than average, it definitely tells a different story.
The average temperature here is less than two degrees below the normal of 77.1. It did hit 90 degrees, but only once on the 5th. And it doesn't even make the top ten coolest Augusts on record. It really goes to show you how different weather can be just a few miles apart in our region. Now that the month is half over, what can we expect as we end it? Will there be a big warm up?
Well, at least a bit of one... The medium range forecast has temperatures near the seasonal average with above average temps nearby . We could hit 90 in there for a day or two if we're lucky (yeah, I wouldn't mind one more). So far, D.C. has had 16 days at 90 degrees or above. On average, we get between 25 and 30 of them in a year. The summers with the fewest 90 degree days were in 1905 and 1886 when there were only 7 days. (Thanks to Alex Liggitt and a previous blog for those last two stats).
At this point in time, I think a lot of us Washingtonians are wondering where the summer has gone. With temperatures in the 50s to low 60s this morning, and highs only near 80 this afternoon, we'll be 7-10 degrees below average across the area. Looking ahead to the 7-Day forecast, summer is expected to return by the end of the weekend. But with the increasing levels of heat and humidity will come a higher likelihood for showers and thunderstorms.
The eastern part of the U.S. has been beautiful this morning due to high pressure filtering in behind yesterday's weak reinforcing cold front. Temperatures were thought to possibly break into the 50s at Reagan National this morning, which would have been the first time in 10 years that has occurred, but low and behold, it only dropped to 62 degrees. I'm guessing chalk that up to the warm water temperature at 77 degrees in the Potomac next to the sensor.
Temperatures will rise slightly into Saturday, back into the mid 80s. By Sunday, a cold front currently situated over Canada will move into the region, bringing a chance for showers and storms by the afternoon and evening. Highs Sunday should reach the upper 80s.
Beyond Sunday, the forecast can be summed up by the one word many of you don't like hearing...unsettled. Monday and Tuesday will feature a chance for storms from a disturbance currently located over the northern Rockies. By Wednesday and Thursday, we'll be under the influence of a trough which is currently over the Pacific Northwest. This set-up will feature dewpoints in the upper 60s all week, along with showers and the chance for afternoon storms.
Taking a look at the precipitation forecast from the Weather Prediction Center above, the D.C. area may see 2 inches of rain or more with locally higher amounts through Friday morning of next week. Not exactly something we really need after the terrible flooding last week. Be sure to dust off the umbrella heading into next week!
So far, the month of August has been slightly cooler than normal. There have only been two days this month with above-average temperatures. Now, let me set the record straight: It hasn't been abnormally cold so far this month, but it will definitely be much cooler than normal over the next two days.
Low temperatures Friday morning and Saturday morning may drop into the 50s at Reagan National Airport. This hasn't happened in 10 years, since August 7th, 2004, when the mercury dropped to 58 degrees. Since 2009, temperatures haven't dropped into the 50s at Reagan National until September 1st, the 11th twice, the 14th and the 15th, so we're nearly a month ahead of where we've been over the past few years.
The average low doesn't eclipse the 50s until September 24th. Looking back a little further into the climate data, temperatures in the 50s in the month of August have been largely absent in D.C. after 2004.
There were numerous times prior to that date though, as Reagan National reached the 50s in August in 2000, 1998, and 1997, four times in 1994, once in 1992 and two times in 1989. That gives 12 occasions in the past 25 years, though none in the past 10. I guess we'll see if we can break the warm streak starting tonight.
The forecast low tonight for D.C. is 60 degrees. As a secondary frontal boundary pushes through the region this afternoon and evening, drier air will settle overhead along with clearing skies overnight. By the early morning, clear skies and light winds should lead to plenty of radiational cooling, which may help D.C. reach its potential. The wild card: The Potomac's water temperature still stands at 77.5 degrees. A slight shift in the wind could keep the temperature from dropping below 60.
BRANDYWINE, Md. (WJLA) – Prince George's County police have closed a bridge in Brandywine until further notice.
Police said the bridge, which is located on South Springfield Road, was washed away by all of the rain on Tuesday.
An estimate on when the bridge and road would reopen to traffic was not available.
Several parts of the D.C. metropolitan region are still recovering from Tuesday’s storms which brought record rainfall to sections of Maryland, D.C. and Virginia.
Anne Arundel County in Green Haven, Maryland received more than 10 inches of rain while Baltimore-Washington International Airport saw a record six inches of rain, the highest recorded in a 24-hour period for that area. Comparatively, Dulles International Airport and Reagan National Airport received 1.13 and 1.16 inches of rain, respectively.
The rain triggered Flash Flood Warnings and closed several low-lying roads in Prince George’s County in Maryland and Fairfax County in Virginia due to high-standing water.
By Wednesday, some roads remained closed with parts of Maryland still experiencing leftover flooding.
BALTIMORE, Md. (AP) - Not since 1933 has Baltimore recorded a rainfall that matched Tuesday's deluge.
Meteorologist Jason Elliott with the National Weather Service said that the 6.3 inches recorded at Baltimore Washington International Thurgood Marshall Airport is the highest total recorded for the city in a single day since a 1933 hurricane that measured 7.6 inches.
Tuesday's rainfall also marks the second-highest total since measurements were first taken in 1871.
And some areas received even higher totals. The weather service reported 10.3 inches of rainfall in Green Haven in Anne Arundel County.
The rainfall caused flash flooding Tuesday that necessitated numerous water rescues around the state.
The good news, Elliott said, is that the heaviest rain occurred in areas close to the Chesapeake, where rivers can more easily drain into the bay.
Yesterday's deluge was a significant one, with record rainfall in parts of the area. BWI recorded its second rainiest day in record history with 6.3 inches of rain (BWI's still-standing record is the 7.62 inches of rain that fell on July 23, 1933 during the 1993 Chesapeake-Potomac hurricane).
Over half (59%) of the rain that we've picked up in #DC so far this summer fell on 3 days. 7/10, 7/15 & yesterday.— Ryan Miller (@RyanMillerABC7) August 13, 2014
Yesterday's rain was courtesy of a strong frontal system sliding through the area. Heavy rain continues for New England today, while we begin to dry out.
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