000
FXUS66 KSTO 192214
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
315 PM PDT FRI MAR 19 2010
.DISCUSSION...WATER VAPOR IMAGERY SHOWS A HIGHLY AMPLIFIED RIDGE OF
HIGH PRESSURE ALONG THE WEST COAST THIS AFTERNOON...WITH AN UPPER
LEVEL LOW MOVING INSIDE OF 140 WEST NEAR 40 NORTH. THIS LOW WILL
SLOWLY HELP SHIFT THE RIDGE AXIS INLAND OVER THE NEXT 24
HOURS...KEEPING TEMPERATURES ABOVE NORMAL AND CONDITIONS DRY ACROSS
THE NORTHERN INTERIOR INTO SATURDAY. HOWEVER...THINGS START TO
CHANGE ON SUNDAY...AS THIS SYSTEM SPLITS AND MOVES INLAND. AT THIS
POINT IN TIME...LIKE THE THINKING OF THE GFS AND NAM...WHICH KEEP
THE MAJORITY OF THE MOISTURE TO OUR NORTH...AS THE CURRENT
ATMOSPHERE ACROSS THE NORTHERN INTERIOR IS VERY DRY. MORNING
SOUNDINGS AT OAKLAND AND RENO SHOWED PWS RANGING BETWEEN 0.08 AND
0.11 INCHES. THEREFORE...THINK THE ECMWF IS OVER DOING THE
PRECIPITATION...WHICH BRINGS SHOWERS DOWN TO THE INTERSTATE 80.
THEREFORE...WILL JUST KEEP A SLIGHT CHANCE OF SHOWERS OVER THE FAR
NORTHERN AREAS FOR SUNDAY AFTERNOON AND NIGHT...WITH JUST SOME HIGH
CLOUDS AND COOLER CONDITIONS ELSEWHERE. DRIER CONDITIONS WILL
DEVELOP ONCE AGAIN BY MONDAY. PALMER
.EXTENDED DISCUSSION (TUESDAY THROUGH FRIDAY)...AREAS OF BREEZY
NORTH TO EAST WIND OVER INTERIOR NORCAL TUESDAY AS MODERATE TO
STRONG UPPER NORTHERLY WIND COMBINES WITH A TIGHT NE-SW SURFACE
PRESSURE GRADIENT. UPPER RIDGE FLATTENS WED AS SHORT WAVE MOVES INTO
THE PAC NW. RIDGING REBOUNDS SLIGHTLY THURSDAY BEFORE A DEEPER
TROUGH MOVES THROUGH FRIDAY. MODELS ARE SIGNIFICANTLY DIFFERENT ON
TIMING/TRACK WITH THIS WAVE LATE IN THE FORECAST PERIOD. ECMWF
HI-RES CONTINUES TO BE WETTEST SOLUTION DEVELOPING PRECIP FARTHER
SOUTH OVER THE INTERIOR FRIDAY. MODEL HAS BEEN OVERDOING PRECIP
LATELY AND FAVOR THE DRIER SOLUTIONS THROUGH THE EXTENDED ATTM.
&&
.AVIATION...VFR MAINLY SKC CONDITIONS THE NEXT 24 HOURS. GENERALLY
LIGHT WINDS ARE EXPECTED AT THE TAF SITES...WITH NORTHEASTERLY WIND
GUSTS UP TO AROUND 25 KT POSSIBLE OVERNIGHT ALONG THE WEST SLOPES OF
THE NORTHERN SIERRA.
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
