Wednesday, August 16, 2017

Weather Discussion for Wednesday August 16, 2017

Normal high and low temperatures for Aug 14-Aug 21 (high/low)...Redding 97/63, Chico 95/58, Quincy 88/41, Chester 83/43, Susanville 87/49, Grass Valley 86/55, Weaverville 92/47, Mt. Shasta 84/48, Yreka 89/50, Alturas 87/41

This blog will be issued every Monday, Wednesday, and Saturday morning and updated if the weather is changing or critical or interesting weather events are occurring.

Things are going to get hotter as the high pressure ridge just off the coast continues to build.  Temperatures today will be above normal with some areas of the north valley hitting the 100 degree mark.   Thursday through Saturday we will have high temperatures 6 to 12 degrees above normal.  Skies will be mostly sunny with afternoon cumulus over the mountains.  There is a chance of isolated afternoon and evening thunderstorms over the Sierra Cascades south of Mt Lassen today and Thursday and over the mountains north and east of the valley Friday and Saturday.  

Over the weekend the high will shift a little westward as a weak upper level low pressure area forms off the coast (see map below).  This low will linger off the coast through early next week.   Temperatures start cooling Sunday and by early next week will down to 2 to 4 degrees above normal.  The low will increase the afternoon and evening thunderstorms.   Sunday and Monday they will confined to the higher elevations but by Tuesday and Wednesday there will be chance of thunderstorms in the valley.

The Old Forecaster.

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Monday, August 14, 2017

Weather Discussion for Monday August 14, 2017

Normal high and low temperatures for Aug 14-Aug 21 (high/low)...Redding 97/63, Chico 95/58, Quincy 88/41, Chester 83/43, Susanville 87/49, Grass Valley 86/55, Weaverville 92/47, Mt. Shasta 84/48, Yreka 89/50, Alturas 87/41

This blog will be issued every Monday, Wednesday, and Saturday morning and updated if the weather is changing or critical or interesting weather events are occurring.

This morning's satellite picture below shows a low pressure trough and frontal system moving into western Canada with the southern end bring some clouds to Northern California.  Further out to the west another frontal system is moving toward the Canadian coast and the southern end of this system will bring a few clouds to the north state tonight and early Tuesday.  These systems could trigger a few light showers over the higher elevations north of Redding.  Temperatures today will cool to 3 to 8 degrees below normal and will remain there Tuesday.  Gusty south to southwest winds are expected this afternoon and gusty southwest to northwest winds Tuesday afternoon.

Late Tuesday a high pressure ridge will be build off the west coast.  This will bring clear skies to our area and warm temperatures back up.  Temperatures Thursday will be 8 to 12 degrees above normal.  Winds will be light.  Friday the high pressure ridge begins to weaken as another low pressure trough moves into Canada (see map below).  Skies will remain mostly clear through the weekend but temperatures will start to cool Friday and should be back to normal by the weekend. 

The Old Forecaster.

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Saturday, August 12, 2017

Weather Discussion for Saturday August 12, 2016

Normal high and low temperatures for Aug 7-Aug 14 (high/low)...Redding 98/63, Chico 96/58, Quincy 90/43, Chester 86/44, Susanville 89/51, Grass Valley 89/57, Weaverville 95/49, Mt. Shasta 86/49, Yreka 92/53, Alturas 89/43

This blog will be issued every Monday, Wednesday, and Saturday morning and updated if the weather is changing or critical or interesting weather events are occurring.

Finally some changes in the large scale weather pattern.   High pressure continues over the west and today will be mostly sunny with some afternoon cumulus over the mountains.    However, this morning's satellite picture shows a low pressure trough and frontal system approaching Canada.   The southern end of this system will brush the far north end of California Sunday and late Monday with a few clouds and maybe an isolated thunderstorm near the Oregon border.  Sunday temperatures will be slightly cooler than and then on Monday temperatures will be a few degrees below normal.  Gusty south to southwest winds will occur this afternoon and Sunday afternoon.  

Tuesday high pressure begins to rebuild off the coast and will hold there for at least the next 5 days (see map below).  Having the high off the coast rather just to our east, like we have had for the last several weeks, will block subtropical moisture from moving northward and will give us periods of northerly winds.  Skies will mostly sunny with temperatures back to 4 to 8 degrees above normal by Thursday and Friday.

The Old Forecaster.

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Wednesday, August 9, 2017

Weather Discussion for Wednesday August 9, 2017

Normal high and low temperatures for Aug 7-Aug 14 (high/low)...Redding 98/63, Chico 96/58, Quincy 90/43, Chester 86/44, Susanville 89/51, Grass Valley 89/57, Weaverville 95/49, Mt. Shasta 86/49, Yreka 92/53, Alturas 89/43

This blog will be issued every Monday, Wednesday, and Saturday morning and updated if the weather is changing or critical or interesting weather events are occurring.

If you look at climatology we are now out of our hottest time of year...the last week of July and the first week of August.  It has been hot, Redding has now had 49 days of 100 degrees or more.

Today through Friday we will be dealing with the weak upper level low pressure area that is along the coast.  The system will try to move eastward but will be stopped by the strong high pressure ridge that continues just to our east.  This means through Friday we will continue have afternoon and evening thunderstorms over the higher elevations with a slight chance in the Redding area. Temperatures will be at or just above normal.  Winds will be light nights and mornings and southerly in the afternoon.

During the weekend a low pressure trough will move through western Canada and the Pacific Northwest (see map below).  This will push the high pressure ridge eastward and kick the low pressure area northeastward.  The trough will bring a few clouds to the far north end of the state and could trigger a shower or thunderstorm over the areas near the Oregon border.   Temperatures will be near or just below normal and gusty southwest winds will occur in the afternoons.  

Monday and Tuesday the north state will see mostly sunny skies.   The cooler air that follows the trough will keep temperatures a little below normal.   Wednesday high pressure will build off the coast.  This means sunny skies and hotter temperatures.  

The Old Forecaster.

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Monday, August 7, 2017

Weather Discussion for Monday August 7, 2017

Normal high and low temperatures for Aug 7-Aug 14 (high/low)...Redding 98/63, Chico 96/58, Quincy 90/43, Chester 86/44, Susanville 89/51, Grass Valley 89/57, Weaverville 95/49, Mt. Shasta 86/49, Yreka 92/53, Alturas 89/43

This blog will be issued every Monday, Wednesday, and Saturday morning and updated if the weather is changing or critical or interesting weather events are occurring.

First a answer to the question i missed in the comments section...These weak upper level lows are common during the summer when high pressure is just to our east.  They can shear off of low pressure trough passing by to the north.

The weak upper level low pressure area is now over northern California and will dissipate as it moves into the high pressure ridge that is over the western U.S.  However, another weak low pressure area will form off the coast by Tuesday afternoon and that system will linger there until Friday.   The lows will cause enough instability to continue the afternoon and evening cumulus cloud development with showers and thunderstorms expected over the mountains.   There is a slight chance of the showers and thunderstorms moving across the north end of the valley.  Temperatures will continue near normal.

This weekend the high pressure ridge will will shift a little eastward as a low pressure area develops in the Gulf of Alaska (see map below).   This will finally allow the weak low pressure area to move northeastward.  Weeekend weather for the north state sunny with temperatures normal of slightly below. 

The Old Forecaster.

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Saturday, August 5, 2017

Weather Discussion for Saturday August 5, 2017

Normal high and low temperatures for July 31-Aug 7 (high/low)...Redding 99/65, Chico 96/58, Quincy 90/43, Chester 86/45, Susanville 89/51, Grass Valley 89/57, Weaverville 95/49, Mt. Shasta 86/50, Yreka 92/53, Alturas 89/43

This blog will be issued every Monday, Wednesday, and Saturday morning and updated if the weather is changing or critical or interesting weather events are occurring.

Redding has now had 46 days of 100 degrees or hotter this summer.

This morning's satellite picture (below) shows the high pressure area over the western U.S. with a weak upper level low pressure area off the coast.   The low has pulled subtropical moisture and clouds northward and you can see the clouds wrapped around the low.  The low will continue moving slowly eastward and will be over Northern California Sunday.   This system will weaken and dissipate Monday and Tuesday as it pushes eastward and runs into the high pressure area.   Today and Sunday the north state will be partly cloudy to partly sunny with a few showers and thunderstorms over the foothills and mountains and a chance of isolated showers and thunderstorms in the valley.  The clouds will affect the temperatures and afternoon readings will range from a couple of degrees below normal to a couple of degrees above normal.   Winds will increase from the south and southwest in the afternoon.  Monday and Tuesday we will see mostly sunny skies with afternoon cumulus clouds and possible thunderstorms over the higher elevations.   Temperatures will be near normal. 

While the high pressure ridge is expected to remain over the western U.S. for at least the next week, there will be another weak low pressure area off the coast by next Thursday (see map below).   This won't have as much sub tropical moisture but could trigger isolated afternoon thunderstorms over the mountains Thursday through the weekend.  Temperatures Wednesday through the weekend will be normal to 5 degrees above normal.

The Old Forecaster.

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Wednesday, August 2, 2017

Weather Discussion for Wednesday August 2, 2017


Normal high and low temperatures for July 31-Aug 7 (high/low)...Redding 99/65, Chico 96/58, Quincy 90/43, Chester 86/45, Susanville 89/51, Grass Valley 89/57, Weaverville 95/49, Mt. Shasta 86/50, Yreka 92/53, Alturas 89/43

This blog will be issued every Monday, Wednesday, and Saturday morning and updated if the weather is changing or critical or interesting weather events are occurring.

Today we will see record or near record temperatures as a strong high pressure area remains over the western U,S,  However, over the next week the high will slowly weaken and weak upper level low pressure area develops off the coast (see map below).   The combination of these events will start a cooling trend Thursday and by Sunday and early next week temperatures will be down to normal or a few degrees above.  

The other feature to watch is the sub tropical moisture which is being drawn northward.   This moisture started reaching our area yesterday and triggered thunderstorms over the Sierra Cascade Crest.   Afternoon and evening mountains thunderstorms will increase across Northern California over the next several days with a chance of thunderstorms at the lower elevations on Friday and the weekend. 

The Old Forecaster.

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