FXUS66 KHNX 242150
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
150 PM PST SUN JAN 24 2010
.SYNOPSIS...
DRIER CONDITIONS ARE EXPECTED TODAY, CLOUDS WILL BEGIN TO ENTER THE
AREA THIS AFTERNOON AS THE WEAK HIGH PRESSURE RETREATS TO THE EAST.
ANOTHER LOW PRESSURE SYSTEM WILL BRING A CHANCE OF RAIN AND SNOW TO
THE AREA LATER THIS AFTERNOON.
&&
.DISCUSSION...
INCREASING MID/HIGH CLOUDS PUSHING INTO THE CENTRAL CA INTERIOR
THIS AFTERNOON AHEAD OF A COLD FRONT WHICH IS APPROACHING THE
WESTERN CONUS COAST. MUCH OF THE DEEPER MOISTURE WITH THIS SYSTEM
IS BEING PULLED NORTHWARD BY A LARGE UPPER LOW CENTERED NEAR
46N/136W AND DRIFTING NORTHWARD AT THIS TIME. WRF CROSS SECTION RH
PROGS INDICATING DEEPER MOISTURE SPREADING SOUTHWARD INTO OUR AREA
TONIGHT AND MONDAY AS THE MOISTURE BAND AHEAD OF THE COLD FRONT SAGS
SLOWLY SOUTHWARD. HAVE GONE WITH CATEGORICAL POPS FOR MERCED AND
MARIPOSA COUNTIES FOR TONIGHT AND HAVE INCREASED POPS FOR ALL
AREAS FOR MONDAY. SINCE THE STRONGER DYNAMICS ARE NOT EXPECTED
UNTIL MONDAY EVENING...THIS LOOKS TO BE MORE OF A HIGH POP/LOW QPF
EVENT THROUGH MONDAY AFTERNOON UNTIL A SHORTWAVE AT THE TRAIL END OF
THE FRONTAL BAND REACHES CENTRAL CA. THIS SYSTEM WILL BRING A SHOT
OF PRECIPITATION TO OUR AREA MONDAY EVENING AND HAVE SUBSEQUENTLY
MENTIONED LIKELY TO CATEGORICAL POPS FOR MOST OF OUR AREA ON
MONDAY NIGHT. RFC QPF PROGS INDICATE THAT SNOWFALL TOTALS IN THE
SOUTHERN SIERRA WILL REMAIN BELOW ADVISORY CRITERIA SO WILL
CONTINUE THE SPECIAL WEATHER STATEMENT EMPHASIZING ADVERSE TRAVEL
CONDITIONS OVER THE HIGHER MOUNTAINS. MEAN THICKNESS VALUES
SUGGEST SNOW LEVELS WILL RANGE BETWEEN 6000 AND 6500 FEET FOR MOST
OF THIS EVENT MONDAY AND MONDAY NIGHT AS MOST OF THE PRECIPITATION
WILL BE IN THE WARM SECTOR AHEAD OF THE COLD FRONT.
BY TUESDAY THE AREA OF EMPHASIS SHIFTS SOUTHWARD AS AN UPPER LOW
BEING EJECTED FORM A CENTRAL PAC SYSTEM APPROACHES THE SOCAL COAST
PROVIDING OUR AREA WITH ANOTHER ROUND OF RAIN AND HIGHER ELEVATION
SNOW. DEPENDING ON THE EXACT TRACK OF THIS SYSTEM...IT HAS THE
POTENTIAL TO BRING SIGNIFICANT PRECIPITATION TO KERN COUNTY...AND
HAVE MENTIONED LIKELY POPS FOR THE KERN COUNTY MOUNTAINS AND
DESERTS FOR TUESDAY NIGHT. HOWEVER...IF THE SYSTEM TAKES A MORE
SOUTHERLY TRACK THAN ANTICIPATED...AS OFTEN IS THE CASE IN THESE
TYPES OF SYSTEMS...OUR AREA MIGHT NOT RECEIVE MUCH PRECIPITATION
FROM IT. CONFIDENCE REMAINS VERY LOW FOR THE TUESDAY AND TUESDAY
NIGHT TIME FRAME...BUT HAVE DECIDED TO NOT MAKE MUCH IN THE WAY OF
CHANGES FOR THIS PERIOD. SOME RESIDUAL BACKWASH PRECIPITATION WILL
BE POSSIBLE OVER THE MOUNTAINS AND KERN DESERTS ON WEDNESDAY
BEFORE A LARGE RIDGE BUILDS INTO CA BY WEDNESDAY NIGHT.
MEDIUM RANGE MODELS CONTINUE TO INDICATE HIGH PRESSURE KEEPING
DRY CONDITIONS OVER THE AREA WEDNESDAY NIGHT THROUGH THURSDAY
NIGHT. HOWEVER...DO NOT EXPECT MUCH IN THE WAY IN TEMPERATURE
RECOVERY AS ANOTHER TROUGH MOVES INTO CA BY LATE FRIDAY. BOTH THE
GFS AND ECMWF INDICATE THIS SYSTEM SPLITTING AS IT NEAR THE COAST
SO IT MIGHT NOT BE MUCH OF A PRECIPITATION PRODUCER AS THE
SOUTHERN PIECE OF IT CROSSES SOCAL FRIDAY NIGHT AND SATURDAY.
THE MODELS ARE ALSO IN AGREEMENT WITH RIDGING RETURNING TO CA BY
NEXT SUNDAY SO HAVE GONE WITH A SLOW DRYING TREND NEXT SATURDAY
NIGHT AND SUNDAY.
&&
.AVIATION...
ACROSS THE SAN JOAQUIN VALLEY AND LOWER FOOTHILLS...VFR WILL PREVAIL
THROUGH 00Z TUESDAY. ISOLATED RAIN NORTH OF FRESNO THIS AFTERNOON...
SPREADING SOUTH THROUGH THE EVENING AND INCREASING IN COVERAGE.
IN THE SOUTHERN SIERRA NEVADA...AREAS MOUNTAIN OBSCURATION IN CLOUDS
AND RAIN/SNOW AFTER 22Z SUNDAY.
IN THE KERN COUNTY MOUNTAINS...VFR WILL PREVAIL THROUGH 00Z TUESDAY
EXCEPT LOCAL IFR CEILINGS IN UPSLOPE CLOUDS AND ISOLATED RAIN/HIGH
ELEVATION SNOW AFTER 08Z MONDAY.
IN THE KERN COUNTY DESERTS...VFR CONDITIONS WILL PREVAIL THROUGH
00Z TUESDAY.
&&
.AIR QUALITY ISSUES...
NONE.
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
