7:00 AM | Less humid today following yesterday's frontal passage

6-Day DC Forecast

Today

Mainly sunny, quite warm, but less humid, highs not far from 90 degrees

Tonight

Mainly clear, comfortable, lows in the middle 60’s

Saturday

Mainly sunny, still quite warm, cannot rule out a shower or thunderstorm late, near 90 degrees

Saturday Night

Partly cloudy skies, mild, cannot rule out a shower or thunderstorm, upper 60’s

Sunday

Mainly sunny, quite warm, near 90 degrees

Monday

Mainly sunny, quite warm, low 90’s

Tuesday

Mainly sunny, quite warm, low 90’s

Wednesday

Mainly sunny, quite warm, near 90 degrees

Discussion

Following yesterday’s frontal passage, less humid air has moved into the Mid-Atlantic region, but it will stay quite warm with high temperatures not far from the 90 degree mark this afternoon. It’ll stay quite warm this weekend as well with plenty of sunshine each day and the warmth will continue into the early part of next week. A cooler pattern, however, will unfold for the latter half of next week as upper level low pressure develops over the Northeast US.

12:35 PM | *Strong-to-severe thunderstorms arrive this afternoon*

[Convective Available Potential Energy (CAPE) values (2500 or higher indicate extreme instability); courtesy NOAA)

Discussion

Strong-to-severe thunderstorms are moving eastward from areas to the west of the I-95 corridor into highly unstable air and should make an early-to-mid-afternoon (1:30-3:00PM) arrival in the DC and Philly metro regions and mid-to-late afternoon (3:00-4:30PM) across New York City. Any thunderstorm can produce heavy amounts of rainfall in a short period of time, frequent lightning, and there can be some potentially damaging wind gusts in some of these storms. The culprit of this activity is the combination of an approaching frontal system, very humid air, and energy in the upper atmosphere.

Severe weather indices are often quite useful to weather forecasters in the determination of atmospheric instability and several of these are raising red flags for the I-95 corridor for this afternoon and early evening. One such index is called Convective Available Potential Energy (CAPE) and readings above 2500 are considered to be “extreme” and suggestive of a very unstable atmosphere. Currently, CAPE values of 2500–3000 extend from SE PA to the DC metro region (circled area) indicating the atmosphere is very unstable. Shut your windows if necessary.

[Latest GOES visible satellite image with N-S frontal boundary zone; courtesy Penn State eWall]

7:00 AM | Strong-to-severe thunderstorm threat this afternoon and evening as front approaches the region...less humid on Friday

6-Day DC Forecast

Today

Partly sunny, hot, humid, afternoon showers and thunderstorms likely, some of the storms can reach strong-to-severe levels and some of the rain can be heavy, highs within a few degrees of 90

Tonight

Chance for lingering early evening showers and thunderstorms; otherwise, becoming partly cloudy late, mild, lows by morning in the mid-to-upper 60's

Friday

Mainly sunny, still quite warm, but less humid, near 90 degrees

Friday Night

Mainly clear skies, comfortable, low-to-mid 60's

Saturday

Partly sunny, quite warm, near 90 degrees; chance for a shower or thunderstorm late in the day or at night

Sunday

Mainly sunny, quite warm, near 90 degrees

Monday

Mainly sunny, quite warm, near 90 degrees

Tuesday

Mainly sunny, quite warm, near 90 degrees

Discussion

Hot and humid weather will continue today, but the bigger story is the threat for afternoon and early evening showers and thunderstorms - some of the storms can reach strong-to-severe levels with brief downpours and potentially damaging wind gusts. All of this activity will be generated by a frontal system that will bring somewhat less humid air to the region on Friday and for much of the weekend. Temperatures today and for the next several days will remain quite warm with highs each afternoon not far from the 90 degree mark. Looking ahead, a cooler weather pattern is likely to become established by the second half of next week in the Mid-Atlantic region. One final note, the moon becomes full by tomorrow and this will actually be the second full moon of the month; otherwise, known as a "blue" moon.

Video

httpv://youtu.be/Qjp5WbdXSk4

7:00 AM | Hot weather continues today with a threat of showers and thunderstorms...approaching front brings another round of showers/storms late tomorrow

6-Day DC Forecast

Today

Partly sunny, hot, humid, cannot rule out a few showers and thunderstorms, some of the rain can be heavy, highs in the low 90’s

Tonight

Partly cloudy, balmy, muggy, cannot rule out a shower or two late, lows in the mid 70’s

Thursday

Partly sunny, hot, humid, chance for showers and thunderstorms, some of the storms can be on the strong side, low 90’s

Thursday Night

Chance for evening showers and thunderstorms; otherwise, mostly cloudy skies, mild, near 70 degrees

Friday

Mainly sunny, still very warm, but a bit less humid, near 90 degrees

Saturday

Mainly sunny, very warm, near 90 degrees

Sunday

Mainly sunny, quite warm, near 90 degrees

Monday

Mainly sunny, quite warm, near 90 degrees

Discussion

One of the hottest stretches of the summer will peak today and tomorrow with some areas along the I-95 corridor reaching the middle 90's for afternoon highs on each day. There will likely be scattered afternoon showers and thunderstorms today and then an approaching frontal system will likely bring a fresh round of showers and thunderstorms to the region later tomorrow and some of the rain can be heavy at times. Following the front, it’ll turn a bit less humid on Friday, but also remain quite warm with highs flirting again with the 90 degree mark. The hot weather is likely to continue this weekend with highs near the 90 degree mark, but a significant pattern change to cooler-than-normal will develop later next week in the Northeast US.

7:00 AM | Hot stretch of weather begins today...change in the pattern develops next week

6-Day DC Forecast

Today

Mainly sunny, hot, humid, cannot rule out an isolated shower or thunderstorm, highs near 90 degrees

Tonight

Mostly clear, mild, muggy, lows not far from 70 degrees

Wednesday

Mainly sunny, hot, humid, cannot rule out a shower or thunderstorm, low 90’s

Wednesday Night

Partly cloudy, mild, low-to-mid 70’s

Thursday

Partly sunny, hot, humid, chance for showers and thunderstorms, low 90’s

Friday

Mainly sunny, still pretty hot, but a bit less humid, near 90 degrees

Saturday

Mainly sunny, hot, near 90 degrees

Sunday

Partly sunny, hot, near 90 degrees

Discussion

The hottest stretch of weather this summer will take place in the I-95 corridor during the next several days as high pressure builds into the region from the Great Lakes. Temperatures should reach or surpass the 90 degree mark each of the next several days with plenty of sunshine expected thanks to the high pressure system. A frontal system will approach the region late Thursday likely generating another round of showers and thunderstorms. This frontal system can really be characterized as a "dry" front as it'll stay pretty hot following the frontal passage on Friday and Saturday, but perhaps a bit less humid. Looking ahead, while this week will feature lots of hot weather, the overall weather pattern will undergo a change next week to cooler-than-normal conditions in the Mid-Atlantic region as we progress through early August.

7:00 AM | Heavy showers and strong storms possible later today...hot weather Tuesday, Wednesday and Thursday...pattern change unfolds next week to cooler-than-normal

6-Day DC Forecast

Today

Mainly cloudy skies, warm, humid, chance for afternoon showers and thunderstorms and some of the rain can be heavy, highs in the mid-to-upper 80’s

Tonight

Scattered evening showers and thunderstorms then becoming partly cloudy late, mild, muggy, lows in the upper 60’s

Tuesday

Mainly sunny, hot, near 90 degrees

Tuesday Night

Partly cloudy, mild, near 70 degrees

Wednesday

Mainly sunny, hot, low 90’s

Thursday

Partly sunny, hot, humid, chance for showers and thunderstorms, low 90’s

Friday

Mainly sunny, warm, less humid, upper 80’s

Saturday

Mainly sunny, quite warm, near 90 degrees

Discussion

A weak cool front will dissipate in the Mid-Atlantic region today, but it will likely provide enough instability in the atmosphere to set off shower and thunderstorm activity as we progress through the day and some of the rain can be heavy. The threat for showers and thunderstorms will continue this evening, but then high pressure will build back into the region for Tuesday and Wednesday and it’ll turn hot. A cool front will then approach the area on Thursday and it is likely to set off more shower and thunderstorm activity which will all be followed by lower humidity conditions on Friday. Looking ahead, while this week will feature hot weather on Tuesday, Wednesday and Thursday, cooler-than-normal weather is likely in the Mid-Atlantic region next week.

Video

httpv://youtu.be/IzHl53UeeVA

7:00 AM | Nice weather to end the work week...weakening cool front approaches the region on Sunday

6-Day DC Forecast

Today

Mainly sunny, still pretty comfortable, highs in the mid-to-upper 80’s

Tonight

Mostly clear, pleasant, lows in the low-to-mid 60’s

Saturday

Mainly sunny, a bit warmer, upper 80’s

Saturday Night

Partly cloudy, mild, upper 60’s

Sunday

Partly sunny, warm, more humid, chance for showers and thunderstorms late, upper 80’s

Monday

Partly sunny, warm, humid, chance for showers and thunderstorms, upper 80’s

Tuesday

Mainly sunny, warm, upper 80’s

Wednesday

Mainly sunny, warm, upper 80’s

Discussion

High pressure remains in control of the weather, but it will pass off the Mid-Atlantic coastline on Saturday. A weakening cool front will approach the region on Sunday and this will increase the chances for shower and thunderstorm activity early next week before another high pressure system builds back into the area.

7:00 AM | The beat goes on...nice weather continues through Saturday and Sunday doesn't look bad either

6-Day DC Forecast

Today

Mainly sunny, comfortable, highs in the low-to-mid 80’s

Tonight

Mostly clear, pleasantly cool, lows in the lower 60’s

Friday

Mainly sunny, nice, mid 80’s

Friday Night

Mainly clear, still quite pleasant, low-to-mid 60’s

Saturday

Mainly sunny, comfortable, mid 80’s

Sunday

Partly sunny, warm, chance for showers and thunderstorms late in the day or at night, upper 80’s

Monday

Partly sunny, warm, chance for showers and thunderstorms, upper 80’s

Tuesday

Mainly sunny, warm, upper 80’s

Discussion

High pressure is in control of the weather in the Northeast US and will remain so right into the weekend. The next chance for showers and thunderstorms is likely to hold off until late in the weekend with the approach of the next cool frontal system.

7:00 AM | Nice weather right into the weekend

6-Day DC Forecast

Today

Sunny, comfortable, highs in the low-to-mid 80’s

Tonight

Mostly clear, pleasantly cool, lows in the lower 60’s

Thursday

Mainly sunny, nice, mid 80’s

Thursday Night

Mainly clear, still quite pleasant, low 60’s

Friday

Mainly sunny, comfortable, mid 80’s

Saturday

Mainly sunny, nice, mid-to-upper 80’s

Sunday

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

Monday

Partly sunny, warm, chance for showers and thunderstorms, mid-to-upper 80’s

Discussion

A cool front slid through the region last night and its passage ushered in much more comfortable air mass that will stick around right into the weekend. High pressure centered over the Northern Plains this morning will control the weather in the Northeast US right into the weekend. The next chance for showers and thunderstorms is likely to hold off until late in the weekend with the approach of another cool frontal system.

7:00 AM | A much more comfortable second half of the week

6-Day DC Forecast

Today

More clouds than sun, still pretty hot, humid, chance for a couple of mid-day or afternoon showers and perhaps a thunderstorm or two, highs near 90 degrees

Tonight

Slight chance for an early evening shower or thunderstorm then becoming partly cloudy and turning noticeably less humid, lows by morning in the middle 60’s

Wednesday

Mainly sunny, much more comfortable, mid-to-upper 80’s

Wednesday Night

Mainly clear, cool, low 60’s

Thursday

Mainly sunny, pleasant, mid 80’s

Friday

Mainly sunny, nice, mid-to-upper 80’s

Saturday

Mainly sunny, warm, mid-to-upper 80’s

Sunday

Partly sunny, quite warm, chance for showers and thunderstorms, upper 80’s

Discussion

A cool front will slide through the region this evening and this will pave the way for a much more comfortable second half of the week. Temperatures today will approach the 90 degree mark and there can be a couple of mid-day or afternoon showers and perhaps even a thunderstorm or two, but then it’ll become much more comfortable in the overnight hours as a new air mass moves into the region. The rest of the week looks quite pleasant with plenty of sunshine each day and comfortable temperatures and humidity levels.

Video

httpv://youtu.be/CSSbPdFEmF8