A perfect Chamber of Commerce Day for CA with crystal clear skies and abundant visibilities, with a warming trend beginning over CA which will peak on Tue/Wed with many CENCAL stations reaching into the 90°’s at the warm spots. Later in the week forecast models show a weak upper level Low Pressure circulation near the SOCAL coastal area on Fri/Sat which may provide for showers or Thunderstorms over the Southern Sierra. Longer Range into the Fantasyland realm shows CA remaining mild and DRY thru Tue, Apr 22nd.
The Penn State Historic and Record website shows the upcoming mini Heat Wave with a +1 to +2 standard deviation, with the higher values into the Great Basin. Record-Setting Temps are not expected on a widespread basis. The next mini Heat Wave for next Sun, Apr 13th shows a +3 standard deviation over northern NV, and with +1 anomalies over CA…again. Unfortunately DRY wx is the rule for the next 16 Day period.
Shasta Lake Storage past 30 Days, showing a gain of 346,600 AF, with a steep climb commencing on Mar 28th.
Oroville Lake Storage past 30 Days, showing a gain of 225,800 AF, with a steep climb also commencing on Mar 28th.
San Luis Reservoir Storage past 30 Days, showing a gain of 156,600 AF, with lake storage beginning to increase on Mar 31st .
Record Low Streamflows recorded Sunday, April 6th on the;
Truckee River at South Lake Tahoe, beating the prior record set in 1977
Carson River at Markleeville, beating the prior record set in 1977
Tuolumne River above Hetch Hetchy, beating the prior record set in 2012
San Joaquin River middle fork, beating the prior record set in 2012
Tule River beating the prior record set in 2013
Kern River, beating the prior record set in 1961
NORTHERN SIERRA 8-Station Precip Index; update
SAN JOAQUIN 5-Station Precip Index; update
Sun, Apr 6th A strong High Pressure ridge moves onshore and intensifies producing fair skies with warming temps while the storm track pushes northward into BC, Canada. Overnight the ridge axis moves into NORCAL.
Mon, Apr 7th The High Pressure ridge increases to 582dm heights over SOCAL as the axis tilts NE into eastern WA/OR. With light winds over CA, temps continue to rise, with 90°’s at the hot spots in the SJV. Overnight the ridge begins to weaken slightly as a trough digs southward from the GOA containing a trailing cold front that produces heavy rains into Vancouver, BC, Canada.
Tue, Apr 8th The High Pressure ridge over CA slowly erodes from the north, with the 582dm heights retreating southward in SOCAL. Temps in the SJV continue to rise with more widespread 90°’s at the favored warm spots. Further west a trough of Low Pressure develops far west of the CA coast. Overnight the High Pressure over CA continues to slowly weaken, as a minor shortwave disturbance flows into the PACNW. The trough west of CA develops into a cut-off Low Pressure circulation
Wed, Apr 9th While pressures continue to slowly fall over CA, the warm temps continue over the inland regions while temps along the coast begin to lower as an onshore flow pattern develops in response to the approaching upper level Low Pressure circulation. Overnight the Low Pressure disturbance begins to migrate eastward toward SOCAL.
Thu, Apr 10th The 570dm Low Pressure disturbance moves eastward toward Pt Conception, with an onshore SW flow over most of CA which increases the onshore flow, with lowering temps, especially near the coast. The moisture field with this storm is very limited, with only some cloudiness moving onshore into SOCAL. Overnight the circulation reaches Pt Conception, which places CENCAL in a backwash easterly flow pattern.
Fri, Apr 11th The 570dm Low Pressure moves onshore into the LA basin, with wrap-around backwash circulation over CENCAL. Some vorticity accompanies the disturbance which may produce a few showers or Thunderstorms over the Southern Sierra, with anvil blowoff debris moving over the SJV. Overnight the circulation moves eastward into the Imperial Valley with diminishing shower activity over SOCAL.
MAX MIN PRECIP
Sat, Apr 12th The SOCAL Low Pressure circulation moves SE into southern AZ and Northern Mexico as High Pressure ridging moves over NORCAL, producing an offshore NE flow pattern over CENCAL with a slow warming trend commencing. Overnight as the Low Pressure kicks into southern NM, the High Pressure ridge over CA strengthens.
Days 8-16, Long Range into Fantasyland Outlook; Day 8 begins;
Sun, Apr 13th shows High Pressure once again rebuilding over CA, with 582dm heights moving onshore over Pt Conception and the ridge axis pushing northward into the PACNW. Warming continues over CA with fair skies.
Mon, Apr 14th shows the High Pressure ridge axis moves over CA and into the Great Basin, with fair skies and warm temps continuing under a dry SW flow pattern.
Tue, Apr 15th shows a weak shortwave trough moves onshore into NORCAL, with lowering pressures and an increase in the onshore flow pattern. Fair skies continue with cooler temps.
Wed, Apr 16th shows the Low Pressure trough axis moves thru CA with only winds and a few clouds, and slightly lower temps, followed by a NW breeze overnight as High Pressure offshore rebuilds and the trough moves into the Great Basin.
Thu, Apr 17th shows steep High Pressure which has built northward into southern Alaska, begins to move onshore over the WCONUS, while troughing continues into the Great Basin, which increases the NW flow pattern with higher winds overnight.
Fri, Apr 18th shows the High Pressure ridge moves over the West Coast with lighter winds and warmer temps under fair skies. Further NW a deep cold trough in the GOA pivots NE into BC, Canada overnight with heavy rains.
Sat, Apr 19th shows flat pressures over CA with a weak onshore flow pattern, while the storm track is far to the north into BC, Canada and CA continues to bask in fair/mild/dry conditions. Overnight a weak shortwave trough develops west of NORCAL.
Sun, Apr 20th shows the shortwave Low Pressure trough sliding down the coast with weak vorticity and little to no moisture field associated with this feature, therefore the sensible impact on CA will be to lower temps again.
Mon, Apr 21th shows the weak Low Pressure trough slides into the coastal region of SOCAL with a NE offshore flow pattern developing over NORCAL.
Tue, Apr 22th shows the Low Pressure trough kicking eastward as High Pressure once again rebuilds over CA.
NEW CA RECORDS
Station New Record Old Record__
Lancaster 30° (Ties) 30° set in 1986
Day 1 – 5 QPF:
At 12Z (9am) Sunday thru the period Thursday night (Friday @4am);
7 Day QPF Chart; the WPC 7-Day QPF showing up to 0.2 inch for portions of the Southern Sierra and near Julian, east of San Diego, with NORCAL and the SJV remaining dry.
16-Day QPF estimates (from the 0Z GFS model) for;
Days 1-7; shows light amts of precip across the Southern Sierra and along the Central and Southern Coastal areas up to 0.1 to 0.2 inch.
Days 8-16; depicts CA DRY thru Tuesday, April 29th.
GFS 384hr, 16Day QPF Chart shows up to >0.1 inch for most of NORCAL, with CEN/SOCAL remaining dry.
Weekly Evapotranspiration rates for the local 7 Counties shows up to 1.25 inch near Merced/Madera up to 1.54 to 1.61 inches in western Kings/Kern Co during the next 7 Days. The Sierra Crest evaporation loss is 0.98 inch in the upper Tuolumne River basin up to 1.47 inch near Isabella.
Water Vapor 4KM Image of the West Coast Sunday, April 6th, 2014, shows a dome of High Pressure moving closer to the CA coastline, with a dry NW flow pattern.
Visible Satellite Image of the CA Sunday, April 6th, 2014, shows abundantly clear skies over CA with offshore winds pushing the coastal stratus far offshore.
If you have any questions please call or text at any time of day or night.
Comments and suggestions always welcome.
Atmospherics Group International
Dan Gudgel Steve Johnson