Area Forecast Discussion
FXUS66 KSTO [Sacramento/WFO CA] 212238 AFDSTO ∨
FXUS66 KSTO 212238 AFDSTO [HEAD]
National Weather Service Sacramento California 3:38pm PDT Thu Aug 21 2014 ∨
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SACRAMENTO CA 338 PM PDT THU AUG 21 2014 [HEAD]
Synopsis. Weak trough over the West Coast with northwest flow aloft will bring dry conditions with a near to a few degrees below normal temperatures through early next week. High pressure moving inland over the West Coast will bring warming to near or a little above normal Tuesday into Thursday. ∨
.SYNOPSIS... WEAK TROUGH OVER THE WEST COAST WITH NORTHWEST FLOW ALOFT WILL BRING DRY CONDITIONS WITH A NEAR TO A FEW DEGREES BELOW NORMAL TEMPERATURES THROUGH EARLY NEXT WEEK. HIGH PRESSURE MOVING INLAND OVER THE WEST COAST WILL BRING WARMING TO NEAR OR A LITTLE ABOVE NORMAL TUESDAY INTO THURSDAY. [DISC]
Discussion. High pressure over the eastern Pacific and a trough over the Pacific Northwest with Northern California in between them with northwest flow aloft today. Low clouds dissipated in the Delta region by 11am this morning but may return again tomorrow morning west of cordelia. Warmer temperatures this afternoon due to higher pressure nudging into the area along with weaker onshore flow and a more shallow marine layer (down to around 1500 ft this afternoon). The Delta region is seeing the biggest warm up (about 12°) compared to yesterday afternoon with weaker winds (25005 kt [28781 mph] versus 24023 kt [27650 mph]). The upper level trough digs down into far Northern California tomorrow bringing a little cooler temperatures especially across the north and locally breezy westerly winds over the ridgetops. Temperatures are expected to be in the mid 80s to low 90s in the valley and 60s and 70s in the mountain tomorrow afternoon which is a few degrees below normal for this time of year. Temperatures will be similar to a little warmer on Saturday and be about the same on Sunday as Northern California lies between ridge of high pressure over the eastern Pacific and a trough over the Western US temperatures are expected to be in the mid 80s to mid 90s in the valley and low 60s to low 80s in the mountains which is near to several degrees below normal for this time of year. ∨
.DISCUSSION... HIGH PRESSURE OVER THE EASTERN PACIFIC AND A TROUGH OVER THE PACIFIC NORTHWEST WITH NORTHERN CALIFORNIA IN BETWEEN THEM WITH NORTHWEST FLOW ALOFT TODAY. LOW CLOUDS DISSIPATED IN THE DELTA REGION BY 11 AM THIS MORNING BUT MAY RETURN AGAIN TOMORROW MORNING WEST OF CORDELIA. WARMER TEMPERATURES THIS AFTERNOON DUE TO HIGHER PRESSURE NUDGING INTO THE AREA ALONG WITH WEAKER ONSHORE FLOW AND A MORE SHALLOW MARINE LAYER (DOWN TO AROUND 1500 FT THIS AFTERNOON). THE DELTA REGION IS SEEING THE BIGGEST WARM UP (ABOUT 12 DEGREES) COMPARED TO YESTERDAY AFTERNOON WITH WEAKER WINDS (25005 KT VERSUS 24023 KT). THE UPPER LEVEL TROUGH DIGS DOWN INTO FAR NORTHERN CALIFORNIA TOMORROW BRINGING A LITTLE COOLER TEMPERATURES ESPECIALLY ACROSS THE NORTH AND LOCALLY BREEZY WESTERLY WINDS OVER THE RIDGETOPS. TEMPERATURES ARE EXPECTED TO BE IN THE MID 80S TO LOW 90S IN THE VALLEY AND 60S AND 70S IN THE MOUNTAIN TOMORROW AFTERNOON WHICH IS A FEW DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. TEMPERATURES WILL BE SIMILAR TO A LITTLE WARMER ON SATURDAY AND BE ABOUT THE SAME ON SUNDAY AS NORTHERN CALIFORNIA LIES BETWEEN RIDGE OF HIGH PRESSURE OVER THE EASTERN PACIFIC AND A TROUGH OVER THE WESTERN U.S. TEMPERATURES ARE EXPECTED TO BE IN THE MID 80S TO MID 90S IN THE VALLEY AND LOW 60S TO LOW 80S IN THE MOUNTAINS WHICH IS NEAR TO SEVERAL DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. [DISC]
Extended discussion (Monday through Thursday) ∨
.EXTENDED DISCUSSION (MONDAY THROUGH THURSDAY) [DISC]
Ridge of high pressure over the eastern Pacific builds into Northern California bringing warmer temperatures into mid-week. Although the ECMWF [European Center for Medium-Range Weather Forecasts model] is showing a cut off low off of the Northern California coast possibly Wednesday and moving inland Thursday which would increase onshore flow bringing some cooling, especially to the Delta and adjacent valley areas. ∨
RIDGE OF HIGH PRESSURE OVER THE EASTERN PACIFIC BUILDS INTO NORTHERN CALIFORNIA BRINGING WARMER TEMPERATURES INTO MID-WEEK. ALTHOUGH THE ECMWF IS SHOWING A CUT OFF LOW OFF OF THE NORTHERN CALIFORNIA COAST POSSIBLY WEDNESDAY AND MOVING INLAND THURSDAY WHICH WOULD INCREASE ONSHORE FLOW BRINGING SOME COOLING, ESPECIALLY TO THE DELTA AND ADJACENT VALLEY AREAS. [DISC]
Northwest flow aloft over interior Northern California with VFR [Visual Flight Rules] conditions the next 24 hours. Southerly wind gusts up to 20 kts [23 mph] through 03Z [8pm PDT] for KRDD [Redding CA] and KRBL [Red Bluff CA]. Local MVFR [Marginal Visual Flight Rules] from stratus/fog in West Delta after 09Z [2am PDT]. ∨
NORTHWEST FLOW ALOFT OVER INTERIOR NORCAL WITH VFR CONDITIONS THE NEXT 24 HOURS. SOUTHERLY WIND GUSTS UP TO 20 KTS THROUGH 03Z FOR KRDD AND KRBL. LOCAL MVFR FROM STRATUS/FOG IN WEST DELTA AFTER 09Z. [AVI2]
STO [Sacramento/WFO CA] Watches/Warnings/Advisories
.STO WATCHES/WARNINGS/ADVISORIES... NONE. [WARN]
18 Miles E Groveland CaSimilar City NA
1:50pm PDT Aug 21 2014
Tonight. Mostly clear, with a low around 57°. WSW wind 6 to 9 mph becoming ENE in the evening.
Friday. Sunny, with a high near 80°. East wind 5 to 13 mph becoming SW in the afternoon. Winds could gust as high as 21 mph.
Friday Night. Mostly clear, with a low around 61°. SW wind 5 to 9 mph becoming light and variable after midnight.
Saturday. Sunny, with a high near 78°. Light south wind becoming WSW 5 to 9 mph in the afternoon.
Saturday Night. Clear, with a low around 60°. WSW wind around 8 mph becoming ENE in the evening.
Sunday. Sunny, with a high near 80°.
Sunday Night. Mostly clear, with a low around 62°.
Monday. Sunny, with a high near 81°.
Monday Night. Mostly clear, with a low around 62°.
Tuesday. Sunny, with a high near 83°.
Tuesday Night. Clear, with a low around 63°.
Wednesday. Sunny, with a high near 85°.
Wednesday Night. Clear, with a low around 65°.
Thursday. Sunny, with a high near 85°.