Expires:No;;819787
FXUS66 KSTO 191100
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
400 AM PDT WED JUN 19 2013
.SYNOPSIS...
A LOW PRESSURE SYSTEM MOVING THROUGH THE PACIFIC NORTHWEST WILL
CONTINUE TO BRING A CHANCE FOR A FEW SHOWERS TO FAR NORTHERN
CALIFORNIA THIS MORNING...OTHERWISE DRY WEATHER IS EXPECTED. HIGH
PRESSURE BEGINS TO REBUILD THURSDAY LEADING TO WARMER WEATHER
ACROSS THE REGION HEADING INTO THE WEEKEND.
&&
.DISCUSSION...
CENTER OF THE DEEP UPPER LOW IS JUST OFF THE MOUTH OF THE COLUMBIA
RIVER EARLY THIS MORNING WHILE THE AXIS OF THE UPPER TROUGH
EXTENDS SOUTHWARD INTO NORCAL. A FEW SHOWERS ARE CONTINUING
AHEAD OF THE TROUGH ACROSS NORTHEAST CALIFORNIA...BUT THESE ARE
EXPECTED TO TAPER OFF DURING THE MORNING AS THE TROUGH LIFTS OUT
TO THE NORTHEAST.
WELL BELOW NORMAL TEMPERATURES WILL CONTINUE ACROSS THE REGION 
TODAY AS COLD ADVECTION CONTINUES ACROSS NORCAL IN THE WAKE OF THE
TROUGH. SURFACE WINDS WILL TRANSITION FROM SOUTHWEST TO NORTHWEST
ACROSS MOST OF THE REGION. CYCLONIC FLOW ALOFT WILL CONTINUE
THURSDAY AS THE UPPER LOW MOVES SLOWLY EAST INTO THE NORTHERN
ROCKIES. TEMPERATURES WILL INCREASE SLIGHTLY ACROSS NORCAL AS THE
AIRMASS ACROSS THE REGION MODIFIES A BIT.
SHORT-WAVE RIDGING RETURNS FOR FRIDAY AND SATURDAY ALLOWING
TEMPERATURES TO RETURN TO AROUND NORMAL OR SLIGHTLY ABOVE...BUT
THE TREND IN THE MODELS THE PAST FEW DAYS HAS BEEN TOWARD WEAKER
RIDGING AND LESS SIGNIFICANT WARMING. FORECAST UNCERTAINTY
INCREASES NEXT WEEK...BUT MODELS ARE HINTING AT PRECIP CHANCES
POTENTIALLY EARLY NEXT WEEK AS DEEPER MOISTURE MOVES ACROSS THE
EPAC INTO NORCAL. THE EC ADVERTISES SIGNIFICANT PRECIP SOUTH TO
AROUND I-80 WITH CYCLONIC FLOW AND LOWER HEIGHTS ACROSS NORCAL
WHILE THE GFS LIMITS PRECIP TO NORTHWEST CALIFORNIA AS WEAK ANTI-
CYCLONIC FLOW IS MAINTAINED OVER NORCAL. WE/LL MONITOR THESE
TRENDS THE NEXT DAY OR SO AND MAY NEED TO BUMP UP PRECIP CHANCES
IN THE FORECAST.
&&
.AVIATION...
GENERALLY VFR CONDITIONS AS THE UPPER LEVEL LOW MOVES TO THE EAST
TODAY. AREAS OF MVFR IN THE DELTA DUE TO STRATUS UNTIL 18Z.
ISOLATED SHOWERS ACROSS SHASTA AND WESTERN PLUMAS COUNTIES THIS
MORNING AS LOW MOVES THROUGH THE AREA.
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$