7:00 AM | 90+ degrees for several days to come

6-Day Forecast

Today

Mostly sunny, hot, chance for showers and thunderstorms during the mid-to-late afternoon hours, highs in the low-to-mid 90’s

Tonight

Mostly cloudy, mild, chance for a shower and thunderstorm, lows in the mid 60’s

Saturday

Mostly sunny, hot, chance for a shower or thunderstorm, low-to-mid 90’s

Saturday Night

Partly cloudy, mild, chance for a shower and thunderstorm, mid-to-upper 60’s

Sunday

Partly sunny, hot, chance for a shower and thunderstorm, low-to-mid 90’s

Monday

Mostly sunny, hot, low 90’s

Tuesday

Mostly sunny, hot, low 90’s

Wednesday

Partly sunny, hot, near 90

Discussion

Our hot weather pattern will continue for the next several days here in the southern Rockies as an upper level trough over the Pacific Northwest will combine with an upper level ridge over the Central Plains to bring strengthening southwesterly flow to the region. Enough moisture will advect into this region from the desert southwest with the southwest flow of air to bring us the chance for scattered showers and thunderstorms over the next few days. By the early and middle of next week the upper level ridge centered over the Plains will expand westward effectively cutting off the moisture source of air to our south and hot conditions will likely be accompanied by rain-free conditions.

Video

httpv://youtu.be/dcBgBH0cY34

7:00 AM | Close to seasonal norms for the weekend; warming trend early next week

6-Day Forecast

Today

Patchy early morning fog then becoming partly sunny, breezy, seasonably cool, highs in the low-to-mid 70’s along coastal locations

Tonight

Mostly cloudy, breezy, cool, fog possible late, lows in the low-to-mid 60’s

Saturday

Patchy fog early; otherwise, remaining mostly cloudy, breezy, cool, near 70

Saturday Night

Mostly cloudy, mild, fog possible late, low 60’s

Sunday

Patchy fog early then becoming partly sunny, milder, mid 70’s

Monday

Patchy fog early; otherwise, mostly cloudy skies, breezy, mild, mid 70’s

Tuesday

Patchy fog early then becoming partly sunny, mild, mid 70’s

Wednesday

Patchy fog early then becoming partly sunny, mild, mid-to-upper 70’s

Discussion

Yesterday’s surge of subtropical moisture has moved out of the region and, while there can be a lingering shower or thunderstorm in the nearby mountains, dry weather should prevail along coastal sections. High pressure will build into the region over the weekend and a warming trend will result early next week following rather seasonal temperatures during the next couple of days.

Video

httpv://youtu.be/dcBgBH0cY34

7:00 AM | Scattered showers and thunderstorms converging on the region

6-Day Forecast

Today

Mostly cloudy skies with scattered showers and thunderstorms, seasonably cool, highs in the low-to-mid 70’s along coastal locations

Tonight

Mostly cloudy, breezy, mild, fog possible late, lows in the low-to-mid 60’s

Friday

Patchy fog early then becoming partly sunny, breezy, seasonably cool, low-to-mid 70’s

Friday Night

Mostly cloudy, mild, fog possible late, low 60’s

Saturday

Patchy fog early then becoming partly sunny, breezy, cool, near 70

Sunday

Patchy fog early; otherwise, mostly cloudy skies, breezy, milder, mid 70’s

Monday

Patchy fog early then becoming partly sunny, mild, mid 70’s

Tuesday

Patchy fog early then becoming partly sunny, mild, mid-to-upper 70’s

Discussion

A surge of subtropical moisture has moved into southern California and has generated scattered showers and thunderstorms converging on the LA metro region. By the weekend, the moisture will diminish and temperatures will trend a little cooler before warming up early next week as high pressure builds into the region.

Video

httpv://youtu.be/aFXh6szkeYE

7:00 AM | Hot weather pattern continues with highs at or above 90 degrees right into next week

6-Day Forecast

Today

Mostly sunny, hot, chance for showers and thunderstorms, highs in the low-to-mid 90’s

Tonight

Mostly cloudy, breezy, mild, chance for a few showers and thunderstorms, lows in the mid 60’s

Friday

Mostly sunny, hot, chance for a shower or thunderstorm, low-to-mid 90’s

Friday Night

Partly cloudy, mild, chance for a shower and thunderstorm, upper 60’s

Saturday

Partly sunny, hot, chance for a shower and thunderstorm, low-to-mid 90’s

Sunday

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

Monday

Partly sunny, hot, low 90's

Tuesday

Partly sunny, hot, slight chance for showers and thunderstorms, near 90

Discussion

Very warm pattern continues in the southern Rockies as strong upper level ridge remains over the Rockies. High temperatures will remain at or slightly above the 90 degree mark during the next several days.

Video

httpv://youtu.be/aFXh6szkeYE

1:15 PM | 100 years ago today in Death Valley, California the highest temperature ever recorded

Discussion

Today’s forecast high temperature for Death Valley, California is a rather pedestrian 120 degrees. Exactly one hundred years ago today, on July 10th 1913, the weather observer at Greenland Ranch in Death Valley recorded a high temperature of 134 degrees. This is the highest air temperature ever reliably recorded on Earth, but it didn’t get that distinction until just recently. The Greenland Ranch weather station was located across the street from what is known today as the Furnace Creek Ranch and it is about 180 feet below sea level.

Death Valley National Park is the largest national park in the continental US and is located in the Mojave Desert of southeast California. It contains a vast range of elevations and landscapes and is known for being a land of extremes including its climate. In fact, the depth and shape of Death Valley contribute greatly to its extreme heat. Specifically, the extreme heat is due to a combination of several factors including the elevation below sea level, the lack of vegetation especially on the lowest part of the valley floor which allows sunlight to directly heat the desert surface, the narrow width of the valley and its north-south orientation which traps air in the valley allowing it to be recycled back down to the valley floor, radiation of heat from the rocky surfaces of the mountains that surround the valley, and the low humidity as dry air heats at a much quicker rate than moist air. Temperatures in Death Valley normally reach or exceed 100 degrees from Mid-May until early October.

During July of 1913, Death Valley endured an intense stretch of hot weather from the 5th through the 14th when the high temperature reached 125 degrees or higher each and every day. In fact, this 10 day stretch ranks as the hottest stretch of weather ever recorded in Death Valley. The hottest days in this stretch occurred from the 9th through the 13th when the high temperature reached at least 129 degrees with the hottest being on July 10th when the record-breaking 134 degrees was measured.

And now for an interesting recent twist to the story. The Death Valley record of 134 degrees was less than a decade old when it fell to a new record. On September 13, 1922, a temperature of 136 degrees was recorded at El Azizia, Libya and this was indeed cited by the World Meteorological Organization (WMO) for nine decades as the world’s highest temperature ever recorded. However, on September 12, 2012, the WMO officially re-certified the 134 degree reading of July 10th 1913 at Death Valley as the all-time highest air temperature ever recorded on Earth after evidence surfaced suggesting the Libya record of 136 degrees was based on a reading from a bad thermometer which was placed in the wrong place (near asphalt) and, in addition, read by an untrained observer.

This particular example of the rewriting of weather history actually cites the many difficulties of comparing high temperature records of today to those from decades ago. One important problem has to do with the fact that many official weather stations have had significant growth in development (housing, roads, concrete, asphalt, etc.) in the immediate regions surrounding the stations. This urban development very likely contributes to some of today’s warmth (“heat island effect”) at many locations; especially, in the Southwest US where populations have doubled or tripled in the past 50 years near official weather stations (e.g. Las Vegas, Phoenix) making record high temperature records of today in those locations somewhat dubious. Even the inhospitable region of Death Valley has had some development in the area surrounding the Furnace Creek weather station with asphalt roads leading to the nearby visitor’s center - all of which makes this long-surviving 100-year old record of 134 degrees very impressive indeed.

7:00 AM | Seasonably cool weather for coastal regions over the next several days

6-Day Forecast

Today

Patchy early morning fog then becoming partly sunny, breezy, seasonably cool, highs in the low 70’s along coastal locations

Tonight

Mostly clear, breezy, mild, fog possible late, lows in the middle 60’s

Thursday

Patchy fog early then becoming partly sunny, breezy, seasonably cool, low 70’s

Thursday Night

Mostly cloudy, mild, fog possible late, low 60’s

Friday

Patchy fog early then becoming partly sunny, breezy, seasonably cool, low 70’s

Saturday

Patchy fog early; otherwise, mostly cloudy skies, breezy, seasonably cool, low 70’s

Sunday

Patchy fog early then becoming partly sunny, milder, mid 70’s

Monday

Patchy fog early then becoming partly sunny, mild, mid-to-upper 70’s

Discussion

An upper level trough will bring in slightly cooler air for the second half of the week with coastal temperatures not far from normal for this time of year. A persistent marine flow of air will keep the usual pattern of late night and early morning low clouds and fog in the region through the end of the week.

7:00 AM | Hot pattern continues along with a daily thunderstorm threat

6-Day Forecast

Today

Mostly sunny, hot, chance for a few showers and thunderstorms and any storm that forms can get quite strong, highs near 90 degrees

Tonight

Mostly cloudy, breezy, mild, chance for a shower and thunderstorm, lows in the mid 60’s

Thursday

Mostly sunny, hot, slight chance for a shower or thunderstorm, low-to-mid 90’s

Thursday Night

Partly cloudy, mild, chance for a shower and thunderstorm, upper 60’s

Friday

Partly sunny, hot, chance for a few showers and thunderstorms, low-to-mid 90’s

Saturday

Partly sunny, hot, chance for showers and thunderstorms, near 90

Sunday

Partly sunny, not as hot, chance for showers and thunderstorms, mid 80’s

Monday

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

Discussion

A cold front moved across the area in the overnight hours and increased low level moisture throughout the region. A disturbance this afternoon will add some instability into the atmosphere and the result could be scattered strong thunderstorms. The threat for thunderstorms may diminish slightly on Thursday, but subtropical moisture will enhance the threat in the Friday through Sunday time period.

7:00 AM | Upper ridge brings above normal temperatures for today to inland locations

6-Day Forecast

Today

Fog early then becoming mostly sunny, breezy, warm, highs in the mid 70’s along coastal locations and higher inland

Tonight

Mostly clear, breezy, mild, fog possible late, lows in the middle 60’s

Wednesday

Patch fog early then becoming mostly sunny, seasonably cool, low 70’s

Wednesday Night

Mostly cloudy, mild, fog possible late, low 60’s

Thursday

Patch fog early then becoming partly sunny, seasonably cool, low 70’s

Friday

Patch fog early then becoming partly sunny, seasonably cool, low 70’s

Saturday

Patch fog early then becoming mostly sunny, milder, mid 70’s

Sunday

Patch fog early then becoming mostly sunny, mild, mid-to-upper 70’s

Discussion

An upper level ridge will continue to build into the area today and this will cause mild conditions with above normal temperatures for this time of year; especially, at inland locations. It’ll turn slightly cooler for the second half of the week as an upper trough reaches the region with temperatures near seasonal norms.

Video

httpv://youtu.be/P9y3tujmSto

7:00 AM | Stays hot today; chance for a strong thunderstorm later today and again on Wednesday afternoon

6-Day Forecast

Today

Mostly sunny, hot, chance for a shower and thunderstorm, highs in the low-to-mid 90’s

Tonight

Partly cloudy, mild, chance for a shower and thunderstorm, lows in the mid 60’s

Wednesday

Mostly sunny, hot, chance for a few showers and thunderstorms and some of the storms can be strong, near 90

Wednesday Night

Partly cloudy, mild, slight chance for a shower and thunderstorm, mid 60’s

Thursday

Mostly sunny, hot, chance for a thunderstorm or two, low 90's

Friday

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

Saturday

Partly sunny, hot, slight chance for showers and thunderstorms, near 90

Sunday

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

Discussion

An upper level ridge will stretch across the region today from the desert southwest to the central Plains and this will keep a rather hot and dry northwesterly flow of air over us. A couple of disturbances will bring us the chance for showers and strong thunderstorms each of the next two afternoons and then the upper ridge will resume control late in the week.

Video

httpv://youtu.be/P9y3tujmSto

12:40 PM | Tropical Storm Chantal heads for the Caribbean

Discussion

It has been quiet in the Atlantic Basin since mid-June with respect to tropical systems, but now Chantal has reached tropical storm status and is churning towards the Caribbean Sea at a pretty good clip. Chantal developed from a strong easterly wave that slipped off the African west coast a few days ago in what is likely to be a pattern that is frequently repeated over the next few months. The 11AM readings on Chantal have sustained winds at 45 mph with gusts to 60 and rapid movement to the west-northwest at 25 mph. An index that we track here at thesiweather.com called the Madden-Julian Oscillation (MJO) is quite supportive of an active period into at least mid-July as the index will remain in territory (i.e., phases 2 and 3) that favor Atlantic Basin tropical activity. The MJO is a tropical disturbance that propagates eastward around the global tropics with a cycle on the order of 30-60 days.

All indications suggest Chantal will reach the Caribbean Sea within the next 36 hours and then approach the island of Hispaniola later this week. A track over this island would likely, at least temporarily, prevent or slow down intensification of Chantal as mountain peaks tend to interrupt the low-level circulation flow (10,000 foot peaks in Dominican Republic). By the weekend, Chantal could very well be in the vicinity of the Bahamas and, ultimately, it could have an effect on the Southeast US.