Moisture arriving

THIS MORNINGS ANALYSIS AT 500MB SHOWED SOUTHERLY FLOW FROM WEST OF THE TIP OF BAJA INTO CALIFORNIA THEN BACKING FROM THE SOUTHEAST AS IT REACHED INTO THE MOJAVE DESERT….THEN OFF SHORE PULLING AROUND THE SAN DIEGO “WARM-CORE” UPPER CUT-OFF. THIS SUBTROPICAL FEATURE CONTINUES TO PUMP UP QUITE A BIT OF MOISTURE WITH PWAT IN THE COLUMN AS MUCH AS 1.6 OVER SOUTHERN CA. IT APPEARS THAT THE AREA BETWEEN TO THE NORTH OF SANTA BARBARA AND TO THE EXTREME SOUTHWEST PORTION OF THE SAN JOAQUIN VALLEY EAST TO THE ANTELOPE VALLEY WILL BE THE FOCUS OF VERY ACTIVE WEATHER TODAY. THIS AREA IS IN THE DIVERGENT NORTHEAST QUAD OF THE UPPER LOW. THE LI INDEX IS FORECASTED CLOSE TO -5 WITH ENERGY AT 1500 J/KG. 😉

NO REAL CHANGES TO THE FORECAST TODAY IN THE MAMMOTH HIGH COUNTRY WITH SCATTERED SHOWERS AND THUNDER POSSIBLE THIS AFTERNOON AND EVENING. THE COOLING TREND CONTINUES WITH MORE RAPID COOLING EXPECTED SUNDAY INTO TUESDAY WITH THE NEW FORMING “COLD-CORE” CUT-OFF MONDAY PM. THE BIG MESSAGE HERE IS THAT WHETHER OR NOT WE GET ANY SIGNIFICANT PRECIP FROM THE PRESENT INFLUX OF MONSOON MOISTURE, IS NOT AS IMPORTANT AS THE REALIZATION, THAT THE SYSTEM WEST OF SAN DIEGO IS REALLY “PRIMING THE PUMP” MOISTURE WISE FOR THE UPCOMING COLD CORE CUT OFF EARLY NEXT WEEK. THE SLOW MOVING COLD-CORE CUTOFF LOW DIGGING OVER CALIFORNIA AND NEVADA WILL BE ABLE TO TAP MOISTURE FROM OLD MEXICO
AND GENERATE A FAIRLY SIGNIFICANT PRECIPITATION EVENT FOR MUCH OF THE GREAT
BASIN, ESPECIALLY SOUTHWEST PORTIONS, THEN WEST TO EASTERN PARTS OF THE SOUTHERN AND CENTRAL SIERRA AND WHITE MTS.

BY WEDNESDAY, AN ALMOST DUE SOUTHERLY FLOW ALOFT WILL KEEP MEXICAN MOISTURE FLOWING NORTHWARD INTO THE DESERT SOUTHWEST. SHOWERS ASSOCIATED WITH THIS UPPER FEATURE SHOULD CONTINUE UNTIL THE UPPER LOW FINALLY EJECTS OUT IN ABOUT A WEEK. AGAIN, THERE IS CHANCE OF SNOW SHOWERS OVER THE HIGHER ELEVATIONS OF THE SIERRA NEAR THE COLD-CORE OF THE UPPER LOW WHERE 500MB TEMPS MAY FALL TO AS LOW AS -20C. THE ECMWF FROM ITS 00Z SATURDAY RUN HAD THE COLD CORE OVER SEQUOIA NP TUESDAY PM, AND THEN JUST OFF SHORE WEST OF PASO ROBLES WEDNESDAY PM THEN ABOUT MAMMOTH THURSDAY PM. THE SAME OPERATIONAL RUN FOR THE GFS HAD THE UPPER LOW ABOUT DEATH VALLEY TUESDAY PM, THEN OVER THE MOJAVE DESERT WEDNESDAY PM. BY THURSDAY PM IT HAS WOBBLED BACK ABOUT OVER BEATTY, NV AGAIN. SO THE ACTUAL POSITION AND TIMING OF THE UPPER COLD CORE CUT-OFF WILL DETERMINE WHEN AND WHETHER THE MAMMOTH HIGH COUNTRY GETS MUCH SNOW OR NOT. 700MB TEMPS WITHIN THE CORE ARE AS COLD AS -2C WITH A LARGE AREA OF BETWEEN 0C AND -1C. STAY TUNED….IT GOING TO GET INTERESTING! 🙂

DR HOWARD AND “THE DWEEBS”……………………..:-)

Looking ahead

QPF:

1. CRFC HAS .11 AND .05 FOR THE HUNTINGTON LAKE AREA THIS SATURDAY AND SUNDAY RESPECTIVELY. HPC 5 DAY HAS A SWATH OF .5 TO .7 QPF FROM ABOUT YOSEMITE TO SEQUOIA THROUGH TUESDAY OF NEXT WEEK.

2. 5 DAY PLAYERS: LOOKING AT THE NEW FRIDAY 12Z WRF

TODAY FRIDAY, MOISTURE CONTINUES TO INCREASE OVER THE AREA IN RESPONSE TO THE CHANNELING BETWEEN TO THE CUT OFF STL OFF THE SC COAST AND THE UPPER HIGH OVER SOUTHERN AZ. THE UPPER LOW IS WEST OF SAN DIEGO. SPOKES OF VORTICITY WILL SPIN OFF THE UPPER CENTER INTO CA TODAY PROVIDING SOME LIFT FOR SHOWERS LATER TODAY.

SATURDAY:

THE UPPER SUB-TROPICAL LOW REMAINS QUASI STATIONARY THROUGH SATURDAY EVENING OFF THE SC COAST UNTIL SATURDAY NIGHT. A DEFORMATION ZONE OF SURFACE CONVERGENCE ASSOCIATED WITH THE SO-CAL LOW WILL PROVIDE SOME BETTER FORCING AND INSTABILITY OVER THE SIERRA SATURDAY PM, FOR A CHANCE OF SHOWERS AND THUNDERSTORMS.

THEN LATE SATURDAY NIGHT, THE UPPER LOW BEGINS TO OPEN AND LIFT NE INTO CALIF0RNIA, AHEAD OF AN APPROACHING UPPER TROF. A MAJOR CHANGE IN THE WEATHER PATTERN WILL THEN BEGIN AS A LONG WAVE TROF APPROACHES THE WEST COAST, PUTTING AN END TO A HOT SUMMER LIKE WEEK OF UNSEASONABLY WARM TEMPS.

THIS TROF WILL COMBINE WITH THE UPPER LOW, CURRENTLY TO THE SOUTH OF US, LIFTING ITS REMAINS; INCLUDING ITS MOISTURE, INSTABILITY AND UVV INTO THE SIERRA BEGINNING EARLY SUNDAY MORNING. AT THE MOMENT, THE TRACK OF THE DYNAMICS OF THE EJECTING LOW IS FAVORED OVER THE CENTRAL SIERRA SUNDAY. THIS IS WHY, HPC IS FAVORING THE SOUTHERN PORTIONS OF THE CENTRAL SIERRA AND THE NORTHERN PORTIONS OF THE SOUTHERN SIERRA FOR THE BULLS-EYE OF PRECIP.

AS THE UPPER SPLITTING TROF DIGS SOUTH INTO CA MONDAY MORNING…WEST WINDS WILL DEFINITELY PICK UP OVER THE SIERRA CREST IN THE MAMMOTH AREA UNTIL THE CUT OFF PROCESS COMPLETES. THE SPLIT THIS TIME IS OVER NORTHERN CALIFORNIA, WITH MOST OF THE ACTION OVER THE CENTRAL AND SOUTHERN SIERRA. IN ADDITION TO SHOWERS IN THE HIGH COUNTRY. THE TREND NOW IS TO DIG THIS SYSTEM A BIT FURTHER WEST NOW WITH A COLD CORE CUT-OFF OVER CENTRAL/SOUTH CENTRAL CALIFORNIA MONDAY NIGHT/TUESDAY AM NEXT WEEK WITH THE 700MB UPPER LOW NEAR BISHOP TUESDAY AM. THIS SHOULD HAVE THE EFFECT OF RECIRCULATING TS/RW’S HERE AND THERE WITH “UPSLOPE PRECIP POSSIBLE”. SOME SNOW IS POSSIBLE IN THE HIGH COUNTRY WITH THIS PATTERN WITH SEVERAL INCHES POSSIBLE BETWEEN MONDAY NIGHT AND TUESDAY NIGHT. HIGH TEMPS ARE HEADED FOR THE UPPER 40S BY TUESDAY PM AT 8000FT. BY TUESDAY AM 12Z, 700MB TEMPS WILL BE ABOUT 0C OR EVEN SLIGHTLY BELOW THERE AFTER. SNOW LEVEL ABOUT 7500 TUESDAY AM?

NEXT WARM UP WILL BEGIN ABOUT THURSDAY, THEN INTO THE FOLLOWING WEEKEND….. DEPENDING UPON HOW QUICKLY EITHER THE LOW FILLS OR MOVES EAST. THE EARLY PART OF THE FOLLOWING WEEK MAY AGAIN REACH THE LOW 70S…

DR HOWARD AND THE DWEEBS………………..:-)