Occasional high cloudiness capped afternoon temps by a few degrees over CENCAL Tuesday afternoon as many CENCAL stations reached into the 90°’s at the warm spots. These temps are about +15° above average. There were a few new Max Temp records set on Tuesday, including the most significant …San Diego, which beat a 127 year old record. Fresno missed a new record by -4° and Bakersfield missed a new record by -3°. The Penn State Record and Historic website places this event with a +2 standard deviation anomaly over SOCAL, with possible new high temps and a +3 standard deviation anomaly over western NV overnight which may also produce a higher chance of high minimum records. The unseasonably warm temps will continue Wed/Thu, then 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, with some cooling for the region.
Record-Setting heat is causing snow-melt as well as evaporation in the Sierra watersheds, an unwelcomed early event.
FORECAST SUMMARIES
Days 1-7;
Wed, Apr 9th While pressures 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 an approaching upper level Low Pressure circulation. Periodic high cloudiness arriving on the SW flow aloft may dampen afternoon temps by a few degrees from their potential max readings. Overnight the Low Pressure disturbance begins to migrate eastward toward SOCAL.
MAX MIN
Thu, Apr 10th The 564dm Low Pressure disturbance moves ENE toward Pt Conception, with an onshore WSW 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 noses closer toward Pt Conception, which places CENCAL in an increasingly southerly backed flow pattern.
MAX MIN
Fri, Apr 11th The 570dm Low Pressure moves onshore near Vandenberg, with wrap-around backwash circulation over CENCAL. Some vorticity accompanies the disturbance which should produce a few showers or Thunderstorms over the Southern Sierra, with anvil blowoff debris moving WNW over the SJV. Overnight the circulation moves eastward into the LA basin, accompanied with a tiny 564dm Low Pressure vort center with a few showers possible over SOCAL, especially the higher terrain.
MAX MIN PRECIP
Sat, Apr 12th The SOCAL Low Pressure circulation moves east into SW AZ as High Pressure ridging moves over NORCAL and up into BC, Canada, 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.
MAX MIN PRECIP
Sun, Apr 13th The 576dm High Pressure ridge axis moves over CA, as a shortwave disturbance pivots into southern BC, Canada bringing light rains as far south as Vancouver, BC. Overnight the rapidly decaying cold front moves into NORCAL with partly cloudy skies. CA remains fair/mild/dry.
MAX MIN
Mon, Apr 14th Flat High Pressure and a westerly flow pattern keep partly cloudy skies over NORCAL and occasionally into CENCAL. Overnight a large slug of moisture aims at the OR coastline.
MAX MIN
Tue, Apr 15th The flow pattern over CA veers NW as High Pressure begins to increase offshore. 700mb charts shows increasing clouds and showers spreading over NORCAL, with precip as far south as Cape Mendocino to Lassen. This is a warm/moist subtropical disturbance containing rich 1.25 inch PWAT atmospheric moisture which brings brief mod/heavy precip into portions of NORCAL.
MAX MIN
Days 8-16, Long Range into Fantasyland Outlook; Day 8 begins;
Wed, Apr 16th shows the moist flow entering NORCAL lifts northward into OR, with partly cloudy skies over CENCAL.
Thu, Apr 17th shows weak High Pressure ridging over CA, shunting the active storm track northward into WA/Vancouver, BC. A large storm is situated into the GOA with a moist SW flow reaching into western Canada. Overnight the large system moves eastward toward western Canada as rainfall increases, as far south as the WA coastline.
Fri, Apr 18th shows the large 522dm Low Pressure storm is nearly stationary west of Vancouver, with a trailing cold front passing thru the PACNW and reaching the far NW corner of CA. A southerly flow aloft develops over CEN/SOCAL, with fair skies and warm temps.
Sat, Apr 19th shows the large storm in the GOA pivots around, while the moist SW flow and mod/heavy rains continue into western Canada as far south as Portland/OR. CA stays fair/mild/dry.
Sun, Apr 20th shows the GOA Low Pressure fading as it pivots NE into the Alaskan panhandle with some precip continuing to reach into western Canada as far south as the Olympic peninsula.
Mon, Apr 21th shows High Pressure rebuilding offshore west of CA as weak Low Pressure fills the Great Basin with a cool NORTH flow pattern developing over CA.
Tue, Apr 22th shows High Pressure nosing into southern BC, Canada as Low Pressure resides into the Great Basin which keeps the cool/dry NORTH flow pattern ongoing over CA, with a few high clouds periodically, especially over the Sierra.
Wed, Apr 23rd shows a new Low Pressure trough approaching the PACNW, as skies over CA remain fair/mild/dry. Overnight the -30°C disturbance intensifies offshore west of OR, with increasing onshore flow moving into NORCAL.
Thu, Apr 24th shows a strong cold front moving into NORCAL with mod/heavy rains reaching as far south as the Golden Gate to Tahoe with post frontal Thunderstorms spreading over NORCAL as the -26°C isotherm reaches Cape Mendocino and cold air advection destabilizes the atmosphere. Partly cloudy skies reach into CENCAL.
NEW CA RECORDS
Station New Record Old Record__
Merced 88° 80° set in 2004
Madera 88° 82° set in 2003
Hanford 90° 84° set in 2000
Long Beach 92° 89° set in 1968
San Diego 87° 82° set in 1885 Beats a 129 year old record!
San Diego 61° Ties 61° set in 2004
PRECIPITATION FORECAST
Day 1 – 5 QPF:
At 12Z (9am) Wednesday thru the period day Sunday night (Monday @4am);
7 Day QPF Chart; shows up to 0.3 inch for the Southern Sierra and up to 0.1 to 0.2 inch for much of NORCAL.
16-Day QPF estimates (from the 0Z GFS model) for;
Days 1-7; shows light amts of precip across the Southern Sierra with up to 0.1 to 0.3 inch.
Days 8-16; depicts >0.3 inch for the far northern portion of NORCAL, with CEN/SOCAL remaining dry.
GFS 384hr, 16Day QPF Chart shows up to 0.5-0.75 inch for the far northern portion of NORCAL, with CEN/SOCAL remaining dry for the period ending thru Thu, April 24th.
EVAPOTRANSPIRATION
Weekly Evapotranspiration rates for the local 7 Counties shows up to 1.34 inch near Merced up to 1.64 to 1.67 inches in western Kings/Kern Co during the next 7 Days. The Sierra Crest evaporation loss is 1.00 inch in the upper Tuolumne River basin up to 1.64 inch near Isabella.
SATELLITE
Water Vapor 4KM Image of the West Coast Tuesday, April 8th, 2014, shows a dome of High Pressure moving over CA, with a contaminated SW flow pattern advecting high level moisture into the region.
Visible Satellite Image of the CA Tuesday, April 8th, 2014, shows partly cloudy skies over CA with SW winds aloft bringing occasional high cloudiness over the region.
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
559-696-9697 559-433-7316