7:00 AM | Offshore flow will boost temperatures for the weekend

6-Day Forecast

Today

Becoming mostly sunny, windy, warmer, highs in the upper 70’s

Tonight

Mostly clear, breezy, cool, lows by morning near 60 degrees

Saturday

Mostly sunny, breezy, even warmer, low 80's

Saturday Night

Mostly clear, cool, breezy, near 60

Sunday

Mostly sunny, still warm, breezy, mid-to-upper 70’s

Monday

Mostly sunny, comfortable, low-to-mid 70’s

Tuesday

Mostly sunny, cooler, near 70

Wednesday

Patchy fog early; otherwise, mostly sunny skies, cool, near 70

Discussion

High pressure will combine with an offshore flow of air to bring warmer conditions to the LA Basin beginning today and continuing through the weekend. Winds will continue to be gusty at times today out of the northeast and could turn around again early next week which would return us to cooler conditions.

7:00 AM | Much cooler air has penetrated into the Rocky Mountain States and snow will accumulate across Wyoming, Idaho and Utah

6-Day Forecast

Today

Mainly cloudy, breezy, much cooler, periods of rain, maybe even a thunderstorm, highs in the upper 50's

Tonight

Mostly cloudy, breezy, cold, still the chance for a few showers or maybe some flakes mixed in, lows by morning in the upper 30’s

Saturday

Mainly sunny, cool, mid-to-upper 60’s

Saturday Night

Mainly clear, cold, low 40’s

Sunday

Mainly sunny, warmer, mid 70’s

Monday

Mainly sunny, warm, near 80

Tuesday

Mainly sunny, mild, near 75

Wednesday

Mainly sunny, nice, low-to-mid 70’s

Discussion

A cool frontal system associated with a strong upper level trough has passed through the region and it will usher in much cooler air for the next couple of days. Temperatures this afternoon will struggle to climb above the low-to-mid 60’s and could bottom out in the upper 30’s by early tomorrow morning. Another chilly day on Saturday will be followed by noticeable modification in temperatures by early next week.

7:00 AM | Significant cool shot reaches the southern Rockies on Friday

6-Day Forecast

Today

Mainly sunny, windy, still comfortably warm, highs in the mid-to-upper 70’s

Tonight

Partly cloudy, turning chilly late with a possible shower, windy, lows by morning in the upper 40’s

Friday

Mainly cloudy, cooler, showers possible, maybe a thunderstorm, low-to-mid 60's

Friday Night

Mainly cloudy, quite chilly, maybe a shower or two, near 40

Saturday

Mainly sunny, cool, mid-to-upper 60’s

Sunday

Mainly sunny, pleasant, near 75

Monday

Mainly sunny, milder, mid-to-upper 70's

Tuesday

Mainly sunny, nice, mid 70’s

Discussion

A cool frontal system associated with a strong upper level trough of low pressure will swing through the region later tonight and pave the way for much cooler conditions on Friday to close out the work week. Temperatures today will climb well up into the 70’s ahead of the front, but will be confined to the lower-to-middle 60's for highs on Friday. Moderation in temperatures will take place later this weekend along with plenty of sunshine and highs by early next week will be back up well up in the 70’s.

Video

httpv://youtu.be/aA3pDQJjx7w

7:00 AM | Remains quite cool for today, but a warm up is coming this weekend

6-Day Forecast

Today

Patchy fog early; otherwise, gradual clearing for the afternoon, breezy, cool, highs near 70 degrees along coastal locations

Tonight

Mostly cloudy, breezy, cool, some patchy fog possible late, lows by morning near 60 degrees

Friday

Becoming mostly sunny, breezy, warmer, mid 70’s

Friday Night

Mostly clear, cool, near 60

Saturday

Mostly sunny, even warmer, upper 70’s

Sunday

Mostly sunny, warm, upper 70’s

Monday

Mostly sunny, warm, mid 70’s

Tuesday

Mostly sunny, warm, mid 70’s

Discussion

Low pressure will continue to bring unsettled and cool weather to the region with some gusty winds up to 25 mph. High pressure will combine with an offshore flow of air to bring warmer conditions to the LA Basin beginning tomorrow and lasting into the early part of next week.

Video

httpv://youtu.be/aA3pDQJjx7w

7:00 AM | Sunshine and 80 degrees for hump day; much cooler at end of week

6-Day Forecast

Today

Mainly sunny, warm, highs near 80 degrees

Tonight

Mostly clear, cool, lows by morning near 50 degrees

Thursday

Mostly sunny, pleasant, mid 70’s

Thursday Night

Partly cloudy, chilly late, maybe a shower or two, mid 40’s

Friday

Mainly cloudy, breezy, cooler, showers possible, near 60

Saturday

Mainly sunny, cool, low-to-mid 60’s

Sunday

Mainly sunny, milder, near 70

Monday

Mainly sunny, nice, low-to-mid 70's

Discussion

An upper level trough will be dropping into the northern Great Basin today from the Pacific Northwest and this will increase southwesterly winds in our region. As a result, high temperatures this afternoon will climb to near the 80 degree mark and relative humidities will drop into the teens. By Friday, the upper level trough will push a cool front through the southern Rockies and it’ll turn noticeably cooler to close out the work week.

Video

httpv://youtu.be/G85YAbC6zFY

7:00 AM | Cooler along the coast for the next couple of days, but weekend looks warmer again

6-Day Forecast

Today

Patchy fog early; otherwise, mostly cloudy skies, breezy, cooler, highs near 70 degrees along coastal locations

Tonight

Mostly cloudy, mild, some patchy fog and drizzle possible late, lows by morning near 60 degrees

Thursday

Early low clouds, fog and possible drizzle then becoming mostly sunny, breezy, cool, near 70

Thursday Night

Mostly cloudy, cool, some patchy fog possible late, near 60

Friday

Becoming mostly sunny, warmer, mid 70’s

Saturday

Mostly sunny, warm, upper 70’s

Sunday

Mostly sunny, warm, upper 70’s

Monday

Mostly sunny, warm, mid-to-upper 70’s

Discussion

Cooler weather will return to the region for the mid-week, but a warming trend will begin on Friday and the warm up looks likely to last through the upcoming weekend.

Video

httpv://youtu.be/G85YAbC6zFY

9:00 AM | Global sea ice update and the connection between the Atlantic Ocean and the Arctic

Discussion

The northern hemisphere sea ice areal extent has increased significantly from last year’s record low amount and is above four other recent years (2007, 2008, 2010, 2011), but it remains below normal for this time of year. Meanwhile, the southern hemisphere continues at above normal levels and recent measurements suggest it has reached the highest level in decades. On a global basis, sea ice areal extent is currently relatively close to normal with the northern hemisphere near its low point for the year (winter approaching) and southern hemisphere near its high (summer approaching). Oceanic cycles play a major role in weather and climate and can also have a significant impact on sea ice in the polar regions and we’ll focus in on that in this discussion with respect to the Arctic region.

(Courtesy University of Illinois "cryosphere")

Two distinct trend lines can be seen in the northern hemisphere sea ice areal extent dating back to the beginning of satellite era observations in 1979 and there seems to be a direct connection with an oceanic cycle in the north Atlantic involving sea surface temperatures. The Arctic region north of the Atlantic Ocean is open to the warmer waters from the south because of the way the ocean currents flow. These warmer waters can flow into the Arctic and prevent sea ice from forming in the North Atlantic. The northern Atlantic Ocean sea surface temperatures are tracked by meteorologists through an index called the Atlantic Multidecadal Oscillation (AMO) and the two distinct trend lines for northern hemisphere sea ice areal extent are quite well correlated with a flip in phases of the AMO in the mid 1990’s from negative (colder water) to positive (warmer water). Specifically, the northern hemisphere sea ice areal extent featured a general sideways trend at above normal levels from 1979 to the mid 1990’s and then, following that flip in the AMO, there has been an overall downward trend to the current below normal values. These oceanic cycles can last for two or three decades and I believe that when the northern Atlantic sea surface temperatures flip back to cooler-than-normal values – perhaps 5 or 10 years from now - the northern hemisphere sea ice areal extent will return to normal or above normal levels - much like it was before the mid 1990’s while the AMO was negative.

In addition to “areal extent”, “volume” is an important parameter to monitor with respect to sea ice to determine possible long-term climatic trends, but it is harder to measure. In fact, there are no Arctic-wide or Antarctic-wide measurements of the volume of sea ice, but it can be estimated for the Arctic using the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) developed at the University of Washington Applied Physics Laboratory/Polar Science Center. PIOMAS blends satellite-observed sea ice concentrations into model calculations to estimate sea ice thickness and volume and comparisons with submarine, mooring, and satellite observations help to increase the confidence of the model results. In general, the overall trends seen for the modeled sea ice volume in the northern hemisphere seem to correlate pretty well with the observed trends seen for areal extent dating back to the beginning of the satellite era. Namely, similar to sea ice areal extent, the volume features a general sideways trend at above normal levels from 1979 to the middle 1990’s and then a downward trend began at that time when the AMO flipped to a positive phase. We’ll continue to monitor all of this at thesiweather.com over the weeks and months to come as we head into the northern hemisphere winter season.

Video

httpv://youtu.be/VraJH6M08pg

9:00 AM | Global sea ice update and the connection between the Atlantic Ocean and the Arctic

Discussion

The northern hemisphere sea ice areal extent has increased significantly from last year’s record low amount and is above four other recent years (2007, 2008, 2010, 2011), but it remains below normal for this time of year. Meanwhile, the southern hemisphere continues at above normal levels and recent measurements suggest it has reached the highest level in decades. On a global basis, sea ice areal extent is currently relatively close to normal with the northern hemisphere near its low point for the year (winter approaching) and southern hemisphere near its high (summer approaching).

Two distinct trend lines can be seen in the northern hemisphere sea ice areal extent dating back to the beginning of satellite era observations in 1979 and there seems to be a direct connection with an oceanic cycle in the north Atlantic involving sea surface temperatures. The Arctic region north of the Atlantic Ocean is open to the warmer waters from the south because of the way the ocean currents flow. These warmer waters can flow into the Arctic and prevent sea ice from forming in the North Atlantic. The northern Atlantic Ocean sea surface temperatures are tracked by meteorologists through an index called the Atlantic Multidecadal Oscillation (AMO) and the two distinct trend lines for northern hemisphere sea ice areal extent are quite well correlated with a flip in phases of the AMO in the mid 1990’s from negative (colder water) to positive (warmer water). Specifically, the northern hemisphere sea ice areal extent featured a general sideways trend at above normal levels from 1979 to the mid 1990’s and then, following that flip in the AMO, there has been an overall downward trend to the current below normal values. These oceanic cycles can last for two or three decades and I believe that when the northern Atlantic sea surface temperatures flip back to cooler-than-normal values – perhaps 5 or 10 years from now - the northern hemisphere sea ice areal extent will return to normal or above normal levels - much like it was before the mid 1990’s while the AMO was negative.

In addition to “areal extent”, “volume” is an important parameter to monitor with respect to sea ice to determine possible long-term climatic trends, but it is harder to measure. In fact, there are no Arctic-wide or Antarctic-wide measurements of the volume of sea ice, but it can be estimated for the Arctic using the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) developed at the University of Washington Applied Physics Laboratory/Polar Science Center. PIOMAS blends satellite-observed sea ice concentrations into model calculations to estimate sea ice thickness and volume and comparisons with submarine, mooring, and satellite observations help to increase the confidence of the model results. In general, the overall trends seen for the modeled sea ice volume in the northern hemisphere seem to correlate pretty well with the observed trends seen for areal extent dating back to the beginning of the satellite era. Namely, similar to sea ice areal extent, the volume features a general sideways trend at above normal levels from 1979 to the middle 1990’s and then a downward trend began at that time when the AMO flipped to a positive phase. We’ll continue to monitor all of this at "thesiweather.com" over the weeks and months to come as we head into the northern hemisphere winter season.

Video

httpv://youtu.be/VraJH6M08pg

7:00 AM | Much improvement compared to yesterday's chilly, wet start to the week

6-Day Forecast

Today

Mainly sunny, noticeably warmer, highs in the upper 70’s

Tonight

Mostly clear, cool, lows by morning in the upper 40’s

Wednesday

Mostly sunny, even warmer, near 80

Wednesday Night

Partly cloudy, cool, near 50

Thursday

Mainly sunny, cooler, low 70’s

Friday

Mainly cloudy, cooler, showers possible, near 60

Saturday

Mainly sunny, cool, mid 60’s

Sunday

Mainly sunny, nice, near 70

Discussion

Yesterday’s main feature, a vigorous upper level trough, has passed by to our northeast and a ridge of high pressure will follow in its wake. This high pressure system will promote warming and drier conditions in the southern Rockies for the next couple of days. Another strong cool shot is likely to reach the area at the end of the week.

7:00 AM | Topsy-turvy week with temperatures - mild today, cool mid-week, mild late week

6-Day Forecast

Today

Mostly sunny, mild, breezy, highs in the mid-to-upper 70’s along coastal locations

Tonight

Mostly cloudy, mild, some patchy fog possible late, lows by morning in the low 60’s

Wednesday

Early low clouds and fog then becoming partly sunny, breezy, cooler, near 70

Wednesday Night

Mostly cloudy, cool, some patchy fog possible late, near 60

Thursday

Early low clouds and fog then becoming mostly sunny, cool, near 70

Friday

Becoming mostly sunny, warmer, mid 70’s

Saturday

Mostly sunny, warm, upper 70’s

Sunday

Mostly sunny, warm, upper 70’s

Discussion

Another mild day in the region will be followed by a cool-down for the mid-week as upper low approaches from the Gulf of Alaska. Once that features passes by, another ridge of high pressure will build into the area and generate warmer conditions by the weekend.