Sunrise 5:41 AM   Sunset 8:11 PM Moonrise 4:39 PM   Moonset 3:39 AM

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FXUS66 KSTO 191957 AFDSTO

Area Forecast Discussion National Weather Service Sacramento CA 1257 PM PDT Sun May 19 2024


SYNOPSIS
Seasonable temperatures will continue today and into early next week. Mostly sunny and dry conditions with periods of breezy winds expected through the next 7 days, strongest winds expected tonight-Monday.

DISCUSSION

Afternoon GOES-18 Satellite analysis reveals some passing mid and upper level clouds across interior NorCal, mostly in the central Sacramento Valley. Locally breezy winds have been observed this morning, with some 10-20 mph speeds reported across the Valley. The strongest winds are expected to begin later tonight and last through Monday.

A trough is currently digging through northeastern WA and will continue to dig into the Great Basin region through Monday, where it will phase with a closed low in SoCal. As the trough and closed low phase together, our current northwesterly flow will transition into a northerly component, and pressure gradients will increase setting up for gusty northerly winds tonight and tomorrow, mainly in the wind prone areas of the western Sacramento Valley along the I-5 corridor. Wind gusts of 30-35 mph are anticipated, along with sustained winds of around 20-25 mph. Strongest winds are expected to develop just after sunrise tomorrow morning, around 7am and last through the evening. The National Blend of Models (NBM) continues to show roughly 50-80% probabilities that there could be local gusts greater than 40 mph during the timeframe of peak winds. At this time, we are not expecting widespread wind gusts greater than 40 mph, however some areas between Red Bluff and Arbuckle could experience local wind gusts of 40 mph. Minimum Relative Humidity (RH) values will fall, with widespread less than 15% RH values forecast for much of the Sacramento Valley tomorrow.
As such, with low RH values and breezy/gusty northerly winds, locally elevated fire weather conditions will exist tomorrow across the western Sacramento Valley.

Tuesday we will see some relief from the gusty northerly winds as northerly flow will weaken as the trough translates to the east.
Our upper level pattern will transition into a northwesterly flow again, and pressure gradients will weaken as a result.
Temperatures will climb on Tuesday into the mid 80s to low 90s across the Delta and Valley and upper 60s to low 80s for the Foothills and mountains. While we remain in northwesterly flow aloft, another shortwave is progged to dig into Washington and Oregon on Wednesday, which will bring another round of northerly winds and cooler temperatures. There is very limited moisture associated with this system, so we are not anticipating any precipitation chances for the area.

.EXTENDED DISCUSSION (Thursday THROUGH Sunday)...

On Thursday, an upper level closed low is forecast to develop over Idaho and place our area under upper troughing. Right now, main weather impacts from this troughing will be cooler temperatures and breezy northerly winds for the western Sacramento Valley. Friday and Saturday, another trough in the PacNW begins to dig southward and keep the area under the influence of upper troughing extending through SoCal, again keeping temperatures cooler. The NBM introduces slight precipitation chances in the northern and eastern foothills and mountains Saturday afternoon, however current probabilities of seeing a trace of rainfall are below 25%, which highlights some of the uncertainty with exact track, strength, and timing of the system. Cluster analysis reveals general agreement that the area will be under the influence of troughing, however the uncertainty lies on the exact track/location.

High temperatures on Saturday will struggle to reach 80 for the Valley, with cooler low 50s to upper 60s for the mountains and Foothills. Sunday, we will warm up slightly as upper level heights are projected to flatten into a more zonal component, with highs reaching the 80s for the Valley and 60s to upper 70s for the foothills/mountains.

AVIATION

VFR conditions prevail over interior NorCal through the forecast period. Light to breezy surface winds, 12 kts or less, expected through 06z. Winds then shift to a predominantly northerly direction overnight, with gusts increasing to 20 to 30 kts within the Sacramento Valley after 09z.

STO WATCHES/WARNINGS/ADVISORIES
None.

Bishop Cut
Click for Map
Sun -- 03:45 AM PDT     Moonset
Sun -- 04:20 AM PDT     3.57 feet High Tide
Sun -- 05:51 AM PDT     Sunrise
Sun -- 11:07 AM PDT     0.16 feet Low Tide
Sun -- 04:45 PM PDT     Moonrise
Sun -- 04:54 PM PDT     2.49 feet High Tide
Sun -- 08:13 PM PDT     Sunset
Sun -- 10:21 PM PDT     0.62 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION

Bishop Cut, Disappointment Slough, San Joaquin River, California, Tide feet

Brandt Bridge
Click for Map
Sun -- 12:40 AM PDT     0.00 knots Slack
Sun -- 03:45 AM PDT     Moonset
Sun -- 03:48 AM PDT     0.67 knots Max Flood
Sun -- 05:51 AM PDT     Sunrise
Sun -- 06:27 AM PDT     -0.00 knots Slack
Sun -- 10:32 AM PDT     -1.04 knots Max Ebb
Sun -- 02:07 PM PDT     0.00 knots Slack
Sun -- 04:42 PM PDT     0.49 knots Max Flood
Sun -- 04:44 PM PDT     Moonrise
Sun -- 06:47 PM PDT     -0.00 knots Slack
Sun -- 08:12 PM PDT     Sunset
Sun -- 10:06 PM PDT     -0.66 knots Max Ebb
Tide / Current data from XTide NOT FOR NAVIGATION

Brandt Bridge, San Joaquin River, California Current, knots

Full Color Weather Map

Link to Loop


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