HAMweather.com Area Forecast Discussion for County Warning Area HNX

Thu, 16 Feb 2012 13:18:34 GMT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
235 AM PST THU FEB 16 2012

.SYNOPSIS...
FROSTY CONDITIONS ARE POSSIBLE IN THE SAN JOAQUIN VALLEY DURING THE 
NIGHT AND MORNING HOURS THROUGH FRIDAY. GUSTY DESERT WINDS ARE ALSO 
EXPECTED IN KERN COUNTY THROUGH THIS AFTERNOON. ANOTHER LOW PRESSURE 
SYSTEM MAY BRING SOME SNOW SHOWERS TO THE SIERRA CREST THIS 
WEEKEND...OTHERWISE DRY CONDITIONS ARE EXPECTED THROUGH PRESIDENTS 
DAY.

.DISCUSSION...
SATELLITE LOOPS SHOW CLOUDS BANKED ALONG THE VALLEY-FACING SLOPES OF 
THE KERN COUNTY MOUNTAINS SOUTH OF THE KERN RIVER CANYON. THE CLOUDS 
THAT HAD BEEN OVER THE SOUTH END OF THE SAN JOAQUIN VALLEY HAVE 
MOSTLY DISSIPATED...AND WITH A COLD DRY AIRMASS MOVING INTO THE SAN 
JOAQUIN VALLEY...EXPECT STRONG RADIATIONAL COOLING TOWARD DAYBREAK. 
LOWS IN THE COLDEST SAN JOAQUIN VALLEY LOCATIONS THIS MORNING WILL 
BE IN THE 29-32 DEGREE RANGE...ALTHOUGH DURATIONS IN MOST AREAS MAY 
BE A COUPLE OF HOURS LESS THAN ORIGINALLY FORECAST.

THE UPPER-LEVEL LOW IS OVER THE CALIFORNIA/BAJA CALIFORNIA BORDER 
THIS MORNING. THE MODELS FORECAST THE LOW TO DROP SOUTHEAST... 
ALLOWING AN UPPER-LEVEL RIDGE TO BUILD INTO CENTRAL CALIFORNIA. THIS 
WILL BRING STABLE CONDITIONS WITH THE POTENTIAL FOR EITHER FROST OR 
FOG IN THE CENTRAL AND SOUTHERN SAN JOAQUIN VALLEY TONIGHT...AND SOME
SPOTS MAY SEE BOTH. LOWS FRIDAY MORNING ARE FORECAST TO BE SLIGHTLY 
COLDER THAN THIS MORNING...BUT WILL HOLD OFF ANY ADVISORY FOR NOW AS 
FOG DEVELOPMENT MAY MITIGATE THE COOLING.

AN UPPER-LEVEL LOW IS FORECAST TO APPROACH VANCOUVER ISLAND FRIDAY 
NIGHT. THE ASSOCIATED TROUGH WILL MOVE INTO THE PACIFIC NORTHWEST... 
THEN DIG SOUTH INTO CALIFORNIA DURING THE DAY SATURDAY. THIS WILL 
BRING A SLIGHT CHANCE OF SHOWERS TO THE SOUTHERN SIERRA NEVADA FOR 
THE WEEKEND. ALTHOUGH THE TROUGH IS FORECAST TO MOVE INTO THE GREAT 
BASIN SUNDAY MORNING...A TRAILING IMPULSE WILL KEEP A SLIGHT CHANCE 
OF SNOW SHOWERS OVER THE HIGH COUNTRY INTO SUNDAY EVENING.

AN EAST-PACIFIC UPPER-LEVEL RIDGE IS FORECAST TO BUILD ONSHORE INTO 
CALIFORNIA NEXT WEEK. THE GFS AND ECMWF ARE IN AGREEMENT THROUGH 
MIDWEEK...THEN THE GFS BRINGS ANOTHER TROUGH INTO THE PACIFIC 
NORTHWEST NEXT THURSDAY WHILE THE ECMWF HAS RIDGING ALONG THE COAST.
THE FORECAST WILL BE DRY NEXT MONDAY THROUGH WEDNESDAY...AND HAVE 
NOT ADDED ANY PRECIPITATION TO THE DAY 8 GRIDS DUE TO MODEL 
DIFFERENCES.

.AVIATION...
MAINLY VFR CONDITIONS ACROSS THE CENTRAL CALIFORNIA INTERIOR THROUGH 
12Z FRIDAY...EXCEPT AREAS OF IFR IN FOG AFTER 08Z IN THE SAN JOAQUIN 
VALLEY. WINDS GUSTING AT OR ABOVE 35 KNOTS ARE EXPECTED IN THE KERN 
COUNTY MTNS AND DESERT FROM 12Z THURSDAY UNTIL 06Z FRIDAY.

.AIR QUALITY ISSUES...
NONE.

.HNX WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY UNTIL 10 AM PST THIS MORNING FOR THE CENTRAL AND
SOUTHERN SAN JOAQUIN VALLEY /CAZ089>092/.

WIND ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR THE KERN COUNTY
DESERTS /CAZ098-099/.