829  
FXUS66 KHNX 192359 AAA  
AFDHNX  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA  
459 PM PDT THU OCT 19 2017  
   
SYNOPSIS
 
 
TEMPERATURES WILL TREND MUCH COOLER THROUGH FRIDAY AS A STORM  
SYSTEM MOVES OVER NORTHERN CALIFORNIA. THIS SYSTEM WILL BRING A  
CHANCE FOR LIGHT PRECIPITATION THURSDAY NIGHT AND FRIDAY ALONG  
WITH AN INCREASE IN WINDS. DRY WEATHER WILL RETURN LATER THIS  
WEEKEND WITH A WARMING TREND INTO EARLY NEXT WEEK.  
 

 
   
DISCUSSION
 
 
SOME MID LEVEL CLOUDS DEVELOPING TOWARDS THE MERCED AREA AHEAD  
OF AN APPROACHING WEATHER SYSTEM. OTHERWISE CLEAR AND DRY  
CONDITIONS ACROSS THE CENTRAL CA INTERIOR. TEMPERATURES RUNNING A  
BIT COOLER TODAY ACROSS MOST OF THE DISTRICT DUE TO THE INCREASED  
ONSHORE FLOW IN ADVANCE OF A LOW PRESSURE SYSTEM DROPPING OUT OF  
THE GULF OF ALASKA. MODELS IN GOOD AGREEMENT WITH THE TIMING OF  
THE SYSTEM AS IT PUSHES SE ACROSS CENTRAL CA LATE TONIGHT AND  
FRIDAY.  
 
SATELLITE IMAGES SHOW A COLD FRONT MOVING INTO N CA AND OR WITH  
LOTS OF COLD UNSTABLE CUMULUS CLOUD FIELD BEHIND THE FRONT.  
MODELS KEEP THE MAIN ENERGY AND MOISTURE TO THE NORTH OF OUR AREA,  
BUT PROG SOME PRECIPITATION ACROSS CENTRAL CALIFORNIA, ESPECIALLY  
NEAR YOSEMITE. THE COLD FRONT AND MOISTURE WILL APPROACH YOSEMITE  
LATE TONIGHT AND MOVE SOUTHWARD INTO KERN COUNTY BY FRIDAY  
MORNING. THE GREATEST AMOUNT OF PRECIPITATION WILL BE TOWARDS THE  
YOSEMITE AREA WHERE A QUARTER TO AS MUCH AS HALF AN INCH WILL BE  
PROBABLE. EVEN THE TEHACHAPI MOUNTAINS COULD SEE A TENTH OF AN  
INCH IN THE NW FACING SLOPES DUE TO STRONG UPSLOPE WINDS.  
OTHERWISE, JUST A FEW HUNDRETHS OF AN INCH IS EXPECTED IN THE SAN  
JOAQUIN VALLEY AND A TENTH OR TWO IN THE FOOTHILLS AS THE FRONTAL  
BAND QUICKLY PUSHES SOUTH THROUGH THE AREA. MOST PRECIPITATION  
OCCURS LATE TONIGHT AND FRIDAY MORNING. SNOW LEVELS START ABOVE  
10000 FT TONIGHT FALLING 8000 FT IN THE SIERRA BY 12Z FRIDAY.  
SNOWFALL AMOUNTS OF 1 TO 3 INCHES ARE POSSIBLE IN THE HIGHER  
ELEVATIONS OF YOSEMITE, WITH LESS THAN AN INCH FARTHER SOUTH. THIS  
SYSTEM MOVES THROUGH QUICKLY. THUS BY FRIDAY AFTERNOON, SHOULD  
SEE JUST SOME LINGERING UPSLOPE SHOWERS IN THE KERN COUNTY  
MOUNTAINS.  
 
A BRIEF PERIOD OF GUSTY WINDS COULD ACCOMPANY THE FRONT ESPECIALLY  
ALONG THE WEST SIDE OF THE VALLEY AS IT MOVES SOUTH THROUGH THE  
VALLEY LATE TONIGHT AND FRIDAY. EXPECT THE STRONGEST WINDS  
BELOW THE PASSES OF THE KERN COUNTY MOUNTAINS AND DESERT AS A  
STRONG UPPER LEVEL WEST WINDS ALIGNS WITH THE SURFACE PRESSURE  
GRADIENTS. ADDITIONAL UPPER LEVEL ENERGY BEHIND THE TROUGH WILL  
MAINTAIN THE STRONG WIND POTENTIAL THROUGH FRIDAY EVENING. A WIND  
ADVISORY HAS BEEN POSTED FOR THE KERN COUNTY MOUNTAINS AND DESERT  
FOR GUSTS UP TO 50 MPH POSSIBLE.  
 
TEMPERATURES WILL COOL BELOW NORMAL FOR THE WEEKEND WITH  
THE COLD AIR BEHIND THE SYSTEM. HOWEVER, THESE COOL TEMPERATURES  
WILL NOT REMAIN FOR LONG. MODELS REMAIN IN GOOD AGREEMENT WITH  
HIGH PRESSURE STRENGTHENING OVER THE REGION BY EARLY NEXT WEEK.  
THIS WILL BRING DRY AND WARMING CONDITIONS FOR NEXT WEEK.  
 

 
   
AVIATION
 
 
AREAS OF MVFR VISIBILITIES DUE TO SMOKE AND HAZE WILL CONTINUE IN  
THE SAN JOAQUIN VALLEY AND ACROSS THE ADJACENT SIERRA NEVADA AND  
FOOTHILLS. AN APPROACHING COLD FRONT WILL SPREAD PRECIPITATION FROM  
NORTH TO SOUTH AFTER 03Z FRIDAY WITH AREAS OF MVFR AND LOCAL IFR  
CONDITIONS WITH MOUNTAIN OBSCURATIONS. CONDITIONS IMPROVING FROM  
NORTH TO SOUTH AFTER 15Z FRIDAY. VFR CONDITIONS WILL PREVAIL IN THE  
KERN COUNTY DESERT.  
 

 
   
AIR QUALITY ISSUES
 
 
NONE.  
 

 
   
CERTAINTY
 
 
THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS MEDIUM.  
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS HIGH.  
 
CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT  
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP FOR ADDITIONAL INFORMATION  
AN/OR TO PROVIDE FEEDBACK.  
 

 
   
HNX WATCHES/WARNINGS/ADVISORIES
 
 
WIND ADVISORY FROM 11 PM THIS EVENING TO 11 PM PDT FRIDAY  
CAZ095-098-099.  
 

 
 

 
 
PUBLIC...MV  
AVN/FW...JEB  
SYNOPSIS...MV  
 
WEATHER.GOV/HANFORD  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab CA Page Main Text Page