Hazardous weather outlook

Models continue to indicate a shift in the weather pattern by
Early next week. A shortwave moving through the pacific northwest
This weekend will begin to flatten the ridge a bit as it
Continues to move east. This opens the door to shortwave energy
Dropping out of the gulf of alaska early next week. By monday
Evening an approaching trough is projected to begin spreading
Precipitation chances southward across the district...Continuing
Through at least midweek as additional shortwave impulses track
Across the area. Afternoon high temperatures will drop back to a
Few degrees below seasonal averages during the period...While the
Chilly overnight lows will warm a few degrees with the increasing
Clouds and precipitation.

Confidence is increasing in a shift to a wetter pattern for central california next week. The upper ridge will be flattened a bit and continue shift east sunday as a shortwave moves across the pacific northwest. Then a trough drops out of the gulf of alaska monday...With precipitation spreading into central california by monday evening. A longwave trough establishes itself along the west coast with additional shortwave impulses rotating through it. This will continue the chance of precipitation over the region through at least thursday...And possibly into next weekend. Afternoon high temperatures will drop back to a few degrees below seasonal averages during the period...While the chilly overnight lows will warm a few degrees with the increasing clouds and precipitation.

Hazardous weather outlook
National weather service san joaquin valley - hanford ca
1023 am pst fri feb 11 2011

Caz095>097-121330-
Kern county mountains-sierra nevada from yosemite to kings canyon-
Tulare county mountains-
1023 am pst fri feb 11 2011

...More active weather next week...

This hazardous weather outlook is for the kern county mountains
And the higher elevations of the southern sierra nevada.

.Day one...Today and tonight

No hazardous weather is expected.

.Days two through seven...Saturday through thursday

A significant change to a wet weather pattern will occur next
Week as a series of storm systems move across the area. It is
Still too early to give exact timing and snowfall amounts...But the
First storm is expected monday night mainly north of kings canyon.
Snow levels will start relatively high but could lower to pass
Levels toward the end of the week. Windy conditions can also be
Expected over the sierra crest and through the passes of the
Tehachapi mountains.

.Spotter information statement...

Skywarn spotter activation will not be needed.

Weather spotters are encouraged to report any significant or
Unusual conditions to the national weather service.

$$

A significant change in the weather pattern will occur early next week as a trough drops out of the gulf of alaska and takes up residence along the west coast for the week. Impulses rotating through the trough will bring periods of precipitation beginning monday afternoon and continuing through at least friday. The models continue to have some timing and strength differences with the impulses...But both the gfs and the ecmwf have been consistent over the past 2 days with wednesday being the wettest day. Both models also bring colder air in by wednesday night...Lowering snow levels to around 3000 ft in the northern portions of the sierra zones and around 4500 ft in the mountains of kern county.

Hazardous weather outlook
National weather service san joaquin valley - hanford ca
715 am pst sat feb 12 2011

Caz089>099-131200-
West central san joaquin valley-east central san joaquin valley-
Southwestern san joaquin valley-southeastern san joaquin valley-
Mariposa madera and fresno county foothills-
Tulare county foothills-kern county mountains-
Sierra nevada from yosemite to kings canyon-
Tulare county mountains-indian wells valley-
Southeastern kern county desert-
715 am pst sat feb 12 2011

...Unsettled weather next week...

This hazardous weather outlook is for all of interior central
California.

.Day one...Today and tonight

Hazardous weather is not expected.

.Days two through seven...Sunday through friday

A large change in the weather pattern is expected to develop early
This coming week. The first in a series of storms is expected to
Arrive in central california sometime monday or monday
Evening...Then remain unsettled through much of the week as
Additional storms move across the region.

While it is still too early to say how much precipitation will
Occur...There will be periods of valley rain and mountain
Snow...And some of the snow could be heavy at times. These will
Be seasonably cold storms...And the snow level at times could
Lower to 2 or 3 thousand feet.

Gusty west to southwest winds will develop in the mountains and
High deserts at times. Locally gusty south to southeast winds may
Occur in the san joaquin valley...Especially the south end and
West side. And...Depending on the time of day these systems move
Through...There could be the threat of thunderstorms in the valley
As well. Rain in the high deserts of kern county should be minimal
Until mid week.

If you have travel or outdoor plans next week...You should monitor
The latest forecasts for further statements...Or possible watches
And warnings on this developing winter weather situation.

.Spotter information statement...

Skywarn spotter activation will not be needed.

Weather spotters are encouraged to report any significant or
Unusual conditions to the national weather service.

$$

One more day of above-normal temperatures in on tap...Then the upper-level ridge over the state will be weakened by the first in a series of short-waves moving through the pacific northwest.

Satellite loop show this series of upper-level troughs over the northern pacific. The first of these troughs is located near 33n/141w...About 800 miles northeast of hawaii. This trough will bring a sharp change in the airmass...With 850-mb temperatures over fresno forecast to drop by around 6 c monday. The short-wave will bring a chance of rain and mountain snow to the northern part of the hanford warning/forecast area monday afternoon...With precipitation continuing to spread south monday night.

The next trough is near 48n/162w...Just south of the aleutian islands. This trough is forecast to deepen as it drops out of the gulf of alaska...And is forecast to reach california wednesday night. This trough will bring another strong push of cold air into the central california interior...With 850-mb temperatures plunging another 4-5 c by 12z thursday. Snow levels thursday morning will drop well into the foothills...And mariposa...Oakhurst and springville could see some accumulations.

Another concern is the very cold airmass aloft. The ecmwf has 500-mb temperatures of -30 to -32 c over the central california interior by 000z friday...With the gfs forecasting a tight gradient from -32 c in the north to -24 c over the tehachapi mountains. The gfs has an area of 100+ j/kg surface-computed cape over the western edge of the san joaquin valley...So have added a slight chance of thunderstorms over the western two-thirds of the valley thursday.

For friday...The gfs and ecmwf 500-mb temperatures are reversed. The 12z gfs has a surface-computed cape of 500+ j/kg over northwestern kern county...With a surface-computed lifted index of -3. If the gfs is correct...There will be a better chance for convection friday and have added a slight chance of thunderstorms over the entire central and southern san joaquin valley and parts of the adjacent foothills.

A short-wave is forecast to drop into the trough friday night...Bringing a reinforcing push of cold air to keep snow levels low. The 12z gfs tries to develop a closed 500-mb 5450-meter low over the northern half of the san joaquin valley by 00z sunday...So the end of the week could be unsettled as well.