Area Forecast Discussion
FXUS66 KSTO [Sacramento/WFO CA] 252146 AFDSTO ∨
FXUS66 KSTO 252146 AFDSTO [HEAD]
National Weather Service Sacramento California 2:46pm PDT Tue Apr 25 2017 ∨
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SACRAMENTO CA 246 PM PDT TUE APR 25 2017 [HEAD]
Synopsis. Weak weather systems will bring light precipitation through Wednesday. Gusty north winds develop late in the week. ∨
.SYNOPSIS... WEAK WEATHER SYSTEMS WILL BRING LIGHT PRECIPITATION THROUGH WEDNESDAY. GUSTY NORTH WINDS DEVELOP LATE IN THE WEEK. [DISC]
Discussion. Dry weather persists across most of interior Northern California as a shortwave ridge nudges into the region. A few showers are moving through the far northern portions of the state as warm advection starts to take hold. Under partly cloudy skies, Central Valley locations have warmed into the upper 60s to lower 70s, with 40s to 60s over the mountains. ∨
.DISCUSSION... DRY WEATHER PERSISTS ACROSS MOST OF INTERIOR NORTHERN CALIFORNIA AS A SHORTWAVE RIDGE NUDGES INTO THE REGION. A FEW SHOWERS ARE MOVING THROUGH THE FAR NORTHERN PORTIONS OF THE STATE AS WARM ADVECTION STARTS TO TAKE HOLD. UNDER PARTLY CLOUDY SKIES, CENTRAL VALLEY LOCATIONS HAVE WARMED INTO THE UPPER 60S TO LOWER 70S, WITH 40S TO 60S OVER THE MOUNTAINS. [DISC]
A series of weak weather systems will pass through the region tonight through Wednesday. Only light precipitation totals are expected with these systems and should occur mainly over the mountains. The timeframe of most widespread precipitation should occur during the day Wednesday. ∨
A SERIES OF WEAK WEATHER SYSTEMS WILL PASS THROUGH THE REGION TONIGHT THROUGH WEDNESDAY. ONLY LIGHT PRECIPITATION TOTALS ARE EXPECTED WITH THESE SYSTEMS AND SHOULD OCCUR MAINLY OVER THE MOUNTAINS. THE TIMEFRAME OF MOST WIDESPREAD PRECIPITATION SHOULD OCCUR DURING THE DAY WEDNESDAY. [DISC]
After these systems pass by, a longwave trough will deepen over the Great Basin in an "inside slider" pattern. This is traditionally a favorable pattern for breezy north winds across Northern California. At this stage it looks like wind gusts in the range of 30–40 mph will be possible Thursday through Friday in the valley… strongest in the San Joaquin Valley. ∨
AFTER THESE SYSTEMS PASS BY, A LONGWAVE TROUGH WILL DEEPEN OVER THE GREAT BASIN IN AN "INSIDE SLIDER" PATTERN. THIS IS TRADITIONALLY A FAVORABLE PATTERN FOR BREEZY NORTH WINDS ACROSS NORTHERN CALIFORNIA. AT THIS STAGE IT LOOKS LIKE WIND GUSTS IN THE RANGE OF 30-40 MPH WILL BE POSSIBLE THURSDAY THROUGH FRIDAY IN THE VALLEY...STRONGEST IN THE SAN JOAQUIN VALLEY. [DISC]
Extended discussion (Saturday through Tuesday) ∨
.EXTENDED DISCUSSION (SATURDAY THROUGH TUESDAY) [DISC]
High amplitude upper ridging in the Eastern Pacific extends over interior Northern California through the weekend resulting in dry conditions with above normal temperatures. Breezy northerly winds from Friday continue into Saturday. Ridging weakens over northern portions of California Monday as a short wave trough digs through the Pacific Northwest into the Great Basin. This will result in minor cooling over northern portions of the forecast area. High pressure rebuilds behind the wave Monday night into Tuesday resulting in a return of breezy northerly wind. Low level CAA [Cold Air Advection - the advection (movement) of cold air into a region] with this flow will offset downslope warming and maintain slightly cooler temps of northern portions Tuesday. ∨
HIGH AMPLITUDE UPPER RIDGING IN THE EPAC EXTENDS OVER INTERIOR NORCAL THROUGH THE WEEKEND RESULTING IN DRY CONDITIONS WITH ABOVE NORMAL TEMPERATURES. BREEZY NORTHERLY WINDS FROM FRIDAY CONTINUE INTO SATURDAY. RIDGING WEAKENS OVER NORTHERN PORTIONS OF CA MONDAY AS A SHORT WAVE TROUGH DIGS THROUGH THE PACNW INTO THE GREAT BASIN. THIS WILL RESULT IN MINOR COOLING OVER NORTHERN PORTIONS OF THE FORECAST AREA. HIGH PRESSURE REBUILDS BEHIND THE WAVE MONDAY NIGHT INTO TUESDAY RESULTING IN A RETURN OF BREEZY NORTHERLY WIND. LOW LEVEL CAA WITH THIS FLOW WILL OFFSET DOWNSLOPE WARMING AND MAINTAIN SLIGHTLY COOLER TEMPS OF NORTHERN PORTIONS TUESDAY. [DISC]
North winds to 25 mph over the San Joaquin Valley into the evening… then generally light winds through Wednesday morning. Scattered light showers over the northern Sacramento Valley after 11pm. ∨
NORTH WINDS TO 25 MPH OVER THE SAN JOAQUIN VALLEY INTO THE EVENING...THEN GENERALLY LIGHT WINDS THROUGH WEDNESDAY MORNING. SCATTERED LIGHT SHOWERS OVER THE NORTHERN SACRAMENTO VALLEY AFTER 11 PM. [AVI2]
STO [Sacramento/WFO CA] Watches/Warnings/Advisories
.STO WATCHES/WARNINGS/ADVISORIES... NONE. [WARN]
25 Apr 2:35pm PDT
Tonight Mostly cloudy, with a low around 50°. WSW wind 5 to 7 mph becoming calm.
Wednesday A 50% chance of showers. Mostly cloudy, with a high near 63°. SSE wind 5 to 10 mph. New precipitation amounts of less than a tenth of an inch possible.
Wednesday Night A 30% chance of showers before 11pm. Partly cloudy, with a low around 48°. South wind 5 to 8 mph becoming light and variable after midnight.
Thursday Mostly sunny, with a high near 68°. Light and variable wind becoming WNW 5 to 9 mph in the afternoon.
Thursday Night Mostly clear, with a low around 45°. NW wind 5 to 8 mph becoming light and variable in the evening.
Friday Sunny, with a high near 69°.
Friday Night Mostly clear, with a low around 48°.
Saturday Sunny, with a high near 74°.
Saturday Night Clear, with a low around 50°.
Sunday Sunny, with a high near 77°.
Sunday Night Mostly clear, with a low around 50°.
Monday Sunny, with a high near 74°.
Monday Night Mostly clear, with a low around 52°.
Tuesday Sunny, with a high near 72°.
Mostly cloudy, with a low around 50. West southwest wind 5 to 7 mph becoming calm.
A 50 percent chance of showers. Mostly cloudy, with a high near 63. South southeast wind 5 to 10 mph. New precipitation amounts of less than a tenth of an inch possible.
A 30 percent chance of showers before 11pm. Partly cloudy, with a low around 48. South wind 5 to 8 mph becoming light and variable after midnight.
Mostly sunny, with a high near 68. Light and variable wind becoming west northwest 5 to 9 mph in the afternoon.
Mostly clear, with a low around 45. Northwest wind 5 to 8 mph becoming light and variable in the evening.
Sunny, with a high near 69.
Mostly clear, with a low around 48.
Sunny, with a high near 74.
Clear, with a low around 50.
Sunny, with a high near 77.
Mostly clear, with a low around 50.
Sunny, with a high near 74.
Mostly clear, with a low around 52.
Sunny, with a high near 72.