Winter Storm in California, May 20, 2014

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
938 AM PDT TUE MAY 20 2014

.UPDATE...RAISED POPS...QPF AND SKY COVER.

&&

.SYNOPSIS...
A LOW PRESSURE SYSTEM ACROSS CENTRAL CALIFORNIA TODAY. UNSETTLED
AND COOL WEATHER WILL RESULT INCLUDING A THREAT OF THUNDERSTORMS
OVER PARTS OF THE AREA AS WELL AS HIGH ELEVATION SNOW. THE LOW WILL
MOVE EAST OF THE AREA LATER IN THE WEEK.

&&

.DISCUSSION...RAISED POPS AND SKY COVER TO BETTER REFLECT
CURRENT CONDITIONS FOR THIS MORNING THROUGH TONIGHT. LATEST RADAR
IMAGERY SHOWS ISOLATED SHOWERS DEVELOPING ALONG THE WEST SIDE OF
THE SJ VALLEY...INCLUDING OVER FAR SOUTHWEST KINGS COUNTY. UPPER
LOW CONTINUES TO PROGRESS SOUTHWARD ALONG CA COAST OR JUST SOUTH
OF THE SF BAY AREA. WE WILL SEE MORE WARP-AROUND MOISTURE MOVING
AROUND THE CENTER OF THE LOW AS THE DAY PROGRESSES OR STORM MOTION
SHIFTING FROM THE NORTHWEST TO A MORE EASTERLY DIRECTION. EXPECT
MORE CONVECTIVE DEVELOPMENT TO CONTINUE AS WE ARE ALREADY SEEING
SOME CUMULUS CLOUDS OVER THE AREA.

&&

.PREV DISCUSSION...RADAR...SATELLITE IMAGERY AND LIGHTNING
DETECTION NETWORKS SHOW ISOLATED THUNDERSTORMS INCREASING IN
COVERAGE ALONG AND EAST OF A LINE FROM KERMAN O LAKE MCCLURE IN
MARIPOSA COUNTY. THUS FAR THE STORMS APPEAR TO WET AS SMITH PEAK
RAWS IN MARIPOSA COUNTY HAS RECEIVED 0.14" OF RAIN THUS FAR. THE
BIG UPPER LOW IS WELL SHOWN ON SATELLITE IMAGERY MOVING OVER THE
BAY AREA AS IT HEADS TO THE EAST/SOUTHEAST. THIS TRAJECTORY WILL
TAKE IT DIRECTLY ACROSS CENTRAL CALIFORNIA DURING THE NEXT FEW
HOURS AND THEN PER FORECAST GUIDANCE INTO THE SOUTHERN SIERRA THIS
AFTERNOON. THIS SCENARIO WILL PRESENT A MYRIAD OF WEATHER,
INCLUDING SIERRA SNOW ABOVE 6500 FEET, LOWER ELEVATION SHOWERS AND
THUNDERSTORMS. THE MOST CONCENTRATED AREA OF PRECIPITATION WILL BE
OVER THE SIERRA WHERE UP TO SEVERAL INCHES OF ACCUMULATION WILL
OCCUR ABOVE 7000 FEET. PROBABLY THE EASIEST FORECAST ELEMENT IS
TEMPERATURE WHERE THE BIG COOLDOWN WILL LIKELY BOTTOM OUT TODAY.

JUST WHERE THE LOW TRACKS AND ITS POSITION WEDNESDAY AND THURSDAY
REMAIN SOMEWHAT QUESTIONABLE. CONFIDENCE IS HIGH THAT FOR TODAY
THE LOW WILL MOVE INTO THE SIERRA. MODELS CONTINUE TO FORECAST THE
LOW TO CROSS THE SIERRA TONIGHT AND SET UP IN THE GREAT BASIN BY
WEDNESDAY MORNING. THIS POSITION OF THE LOW WILL ALLOW FOR WRAP
AROUND SHOWERS AND THUNDERSTORMS TO CONTINUE IN THE SIERRA AND
THEN WORK SOUTHWARD INTO THE KERN COUNTY MOUNTAINS AND DESERT. THE
LOW IS THEN PROJECTED TO SPLIT WITH AND A SECONDARY WEAKER CENTER
TAKING SHAPE OVER SOUTHERN CALIFORNIA ON THURSDAY. THE SMALL
THREAT OF MAINLY SIERRA SHOWERS WILL CONTINUE INTO THURSDAY
EVENING BEFORE FINALLY ON FRIDAY THE LOW MOVES EAST.

A ROBUST WARMING TREND WILL OCCUR FROM WEDNESDAY THROUGH FRIDAY AS
HEIGHTS RAPIDLY INCREASE IN THE WAKE OF TODAY'S RATHER DEEP LOW.
THE UPCOMING MEMORIAL DAY WEEKEND LOOKS ABOVE NORMAL WITH DRY
WEATHER.

&&

.AVIATION...
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS CAN BE EXPECTED
IN THE SAN JOAQUIN VALLEY AND ADJACENT FOOTHILLS THROUGH 06Z
WEDNESDAY. SHOWERS AND THUNDERSTORMS WILL BE MORE NUMEROUS
OVER THE MOUNTAINS DURING THIS PERIOD WITH AREAS OF MVFR AND
IFR. VFR CONDITIONS WILL PREVAIL ELSEWHERE ACROSS THE CENTRAL
CALIFORNIA INTERIOR DURING THE NEXT 24 HOURS.

&&

.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.

THIS INFORMATION IS PROVIDED AS PART OF A TRIAL PROJECT CONDUCTED
BY THE NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD.
CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL
INFORMATION AND/OR TO PROVIDE FEEDBACK.

&&

.CLIMATE...
             RECORDS
SITE DATE    HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR

KFAT 05-20      102:1947     61:1921     71:1897     44:1962
KFAT 05-21      104:1892     56:1933     69:2001     42:1975
KFAT 05-22      104:1967     67:2010     71:1892     43:1909

KBFL 05-20      103:1942     65:1923     70:2001     42:1902
KBFL 05-21      103:1988     65:1903     71:2001     42:1902
KBFL 05-22      102:2001     68:2010     73:1967     36:1903
&&

.HNX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 11 PM PDT THIS EVENING ABOVE 7000
FEET FOR THE CAZ096-097.

&&

PUBLIC...BSO
AVN/FW...DS
PREV DISCUSSION...DUDLEY
SYNOPSIS...JDB

WEATHER.GOV/HANFORD

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
1208 PM PDT MON MAY 19 2014

CAZ096-097-201915-
SIERRA NEVADA FROM YOSEMITE TO KINGS CANYON-
TULARE COUNTY MOUNTAINS-
1208 PM PDT MON MAY 19 2014

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE HIGHER ELEVATIONS OF
THE SOUTHERN SIERRA NEVADA.

WINTER WEATHER ADVISORY IN EFFECT FROM 11 AM TO 11 PM PDT
TUESDAY.

...HIGH COUNTRY SNOW...

.DAY ONE...THIS AFTERNOON AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

HIGH ELEVATION SNOW POSSIBLE TUESDAY AND TUESDAY NIGHT. SEE
SFOWSWHNX FOR MORE DETAILS.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION IS NOT ANTICIPATED.

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT OR
UNUSUAL CONDITIONS TO THE NATIONAL WEATHER SERVICE.

CAZ089>094-201915-
WEST CENTRAL SAN JOAQUIN VALLEY-EAST CENTRAL SAN JOAQUIN VALLEY-
SOUTHWESTERN SAN JOAQUIN VALLEY-SOUTHEASTERN SAN JOAQUIN VALLEY-
MARIPOSA MADERA AND FRESNO COUNTY FOOTHILLS-
TULARE COUNTY FOOTHILLS-
1208 PM PDT MON MAY 19 2014

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE CENTRAL AND SOUTHERN
SAN JOAQUIN VALLEY AND THE ADJACENT FOOTHILLS.

...POSSIBLE THUNDERSTORMS...

.DAY ONE...THIS AFTERNOON AND TONIGHT

NO HAZARDOUS WEATHER EXPECTED.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

* TIMING: POSSIBLE AFTERNOON AND EVENING THUNDERSTORMS TUESDAY
  AFTERNOON AND CONTINUING THROUGH THURSDAY.

* LOCATIONS INCLUDE: MOST OF THE SIERRA NEVADA FOOTHILLS AND IN THE
  SAN JOAQUIN VALLEY MAINLY NORTH OF KERN COUNTY.

* IMPACTS: THUNDERSTORMS CAN PRODUCE LOCALLY HEAVY RAIN, FREQUENT
  LIGHTNING AND SMALL HAIL.

* STAY TUNED TO NOAA WEATHER RADIO...OR YOUR FAVORITE NEWS
  SOURCE...FOR FURTHER INFORMATION.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION IS NOT ANTICIPATED.

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT OR
UNUSUAL CONDITIONS TO THE NATIONAL WEATHER SERVICE.

JDB