SOARING FORECAST, DECEMBER 2 TO 5, 2011

WEEKEND SOARING FORECAST, DECEMBER 2 TO 5, 2011

The NOAA meteorologists have created a succinct synopis of current weather events. These guys live for this kind of weather and their usual terse synopis is filled with adjectives. It’s also a bit longer than normal. I’ll let them describe whats going on without my usual summary in the lower part of this posting.


ALTHOUGH THE NWS IS FORECASTING NORTH TO NORTHEAST WINDS, Dr. Jacks reports indicate South to Southeasterly breezes at the boundary layer over the next four days. I think there is considerable variation in the different weather scenarios due to the unsettled nature of the atmosphere and therefore difficulty in predicting conditions accurately.

IN ANY CASE: Dr. Jacks reports happily forecast excellent lift of up to 500 FPM in our local foothills to 8,500 feet for most of this period. It will be SUNNY AND CLEAR and I assume a good deal of solar energy to hit the ground.

Should the Northeast wind dominate at our location we will likely have good ridge soaring and bow wave occur. Our local weather statistician and CFIG Dale Masters says this weather scenario usually means ridge lift and bow wave.
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This is an excellent time to review with your instructor X-wind takeoffs, landings, headwinds and wind gradient compensation.
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Report below from Thursday AM.
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.SHORT TERM (TODAY-SUN)…
A VERY STRONG AND RATHER ATYPICAL WIND EVENT UNDER WAY. COLD 545DM
UPPER LOW IS OVER NEEDLES. IT IS BRINGING VERY STRONG UPPER LEVEL
NORTH WINDS OVER L.A. COUNTY. THESE NORTH WINDS HAVE COMBINED WITH A
GREAT DEAL OF COLD AIR ADVECTION (WHICH PROMOTES DOWNWARD TRANSPORT
OF THE STRONG WINDS ALOFT) AND VERY STRONG NORTHERLY OFFSHORE SFC
PRESSURE GRADIENT (IN FACT THE KBFL TO KLAX GRADIENT WAS 8.2 MB
WEDNESDAY AFTERNOON WHICH IS THE GREATEST IT HAS EVER BEEN IN
NOVEMBER SINCE 1999) TO CREATE A VERY STRONG NORTH WIND EVENT OVER
L.A. COUNTY. HIGH WIND WARNING LEVEL GUSTS OF 58 MPH OR GREATER HAVE
BEEN RECORDED IN EVERY PORTION OF L.A. COUNTY EXCEPT THE ANTELOPE
VLY AND THE COASTAL SECTION AND EVEN IN THOSE AREAS WINDS HAVE BEEN
STRONG ENOUGH TO CREATE LOTS OF PROBLEMS. NOT TOO MUCH GOING ON IN
THE VTA COUNTY COASTS AND VLYS AS THE WINDS ARE REALLY ONLY FOCUSED
ON L.A. COUNTY. THERE WILL BE SOME WARNING LEVEL GUSTS ACROSS THE
HIGHER PEAKS IN THE VTA MTNS…SOME ADVISORY LEVEL GUSTS IN THE ERN
VLYS (AND MOSTLY THIS MORNING)…AND HARDLY ANYTHING AT THE COAST.
THE WINDS WILL CONTINUE AT THEIR CURRENT VELOCITIES THROUGH THE
MORNING AND THEN WILL DIMINISH A BIT IN THE AFTERNOON AND EARLY
EVENING BEFORE REVING UP AGAIN.

THIS IS A VERY COLD AIRMASS AND WIND SHELTERED AREAS AWAY FROM THE
COAST WILL SEE SOME PATCHY FROST THIS MORNING. THE COLD AIRMASS WILL
REALLY DROP MAX TEMPS WITH MOST COASTAL AND VLY AREAS ONLY MAKING IT
INTO THE MID 60S. THERE IS ENOUGH OFFSHORE DOWNSLOPING WINDS TO
CREATE ENOUGH COMPRESSIONAL HEATING TO PRODUCE SOME MAX TEMPS IN THE
LOWER 70S. THE INTERIOR WILL JUST BE COLD THOUGH WITH HIGHS IN THE
MID 50S.

THERE IS A LITTLE LOW LEVEL MOISTURE WRAPPING AROUND IN THE CYCLONIC
FLOW ALOFT AND THIS IS PILING UP CLOUDS ACROSS THE SAN GABRIEL MTNS
AS WELL AS THE ANTELOPE VLY FOOTHILLS. THE SAN GABRIELS WILL PROVIDE
ENOUGH OROGRAPHIC UPLIFT TO CREATE A SLGT CHC OF SNOW SHOWERS.

ROUND TWO OF THIS WIND EVENT WILL OCCUR OVERNIGHT TONIGHT AS THE
UPPER SUPPORT TURNS MORE NORTH EASTERLY AND MORE OF A TYPICAL SANTA
ANA SETS UP. THIS WILL CREATE MORE WINDY CONDITIONS THROUGH VENTURA
COUNTY AND LESS WINDY CONDITIONS ACROSS THE SAN GABRIEL VLY. WOULD
NOT BE SURPRISED IF THE SAN GABRIEL VLY WIND WARNING IS CANCELLED
LATER THIS AFTERNOON. THERE WILL BE MUCH LESS WIND ACROSS THE
INTERIOR AND ALL ACROSS SLO AND SBA COUNTIES. WITH A VERY COLD
AIRMASS IN PLACE THERE WILL LIKELY BE QUITE A FEW AREAS WITH BELOW
FREEZING OVERNIGHT LOWS. THERE IS A GOOD POSSIBILITY THAT A FEW
FROST OR FREEZE ADVISORIES WILL BE ISSUED THIS AFTERNOON.

NEW WRF WRAPS UP THE WIND EVENT PRETTY QUICKLY ON FRIDAY MORNING. IT
STILL LOOKS GOOD FOR MANY WARNING LEVEL GUSTS TO OCCUR THROUGH MID
MORNING…BUT IF THE WRF IS RIGHT THE WARNINGS MAY HAVE TO CANCELLED
A FEW HOURS EARLY. STILL CHILLY WITH 566 DM HGTS OVERHEAD AND WITH
LESS COMPRESSIONAL HEATING THE COAST AND VLYS WILL LIKELY COOL A FEW
DEGREES FROM TODAYS VALUES.

INTERESTING FORECAST FOR THE WEEKEND. TODAYS UPPER LOW KICKS OUT
FRIDAY EVENING AND THE OFFSHORE SFC FLOW RELAXES AS DOES THE UPPER
SUPPORT. SO THERE WILL NOT BE MUCH IN THE WAY OF WINDS FRIDAY
EVENING THROUGH EARLY SATURDAY MORNING. THE DRY COLD AIRMASS SITTING
UNDER CLEAR SKIES WITH LIGHT WINDS WILL MAKE FOR A PERFECT RECIPE
FOR GOOD COOLING AND MANY AREAS WILL LIKELY SEE BELOW FREEZING
TEMPERATURES.

LATER SATURDAY MORNING ANOTHER SHOT OF COLD AIR ARRIVES COURTESY OF
ANOTHER UPPER LOW EMBEDDED IN A POS TILT TROF THAT RUNS FROM LAS
VEGAS TO MINNESOTA. THIS IS GOOD COLD WINTER AIR FROM THE INTERIOR.
THIS COLD AIR WILL KICK OFF ANOTHER WIND EVENT DURING THE DAY SORT
OF OPPOSITE OF A NORMAL PRESSURE GRADIENT WIND EVENT THAT PEAKS IN
THE MORNING AND RELAXES IN THE AFTERNOON. THIS WILL BE A MODERATE
NORTHEAST WIND EVENT AND WIND ADVISORIES WILL LIKELY BE NEEDED FOR
THE NORTHEAST WIND PRONE AREAS. THE REINFORCING SHOT OF COLD AIR
WILL KEEP MAX TEMPS ON THE COOL SIDE.

THERE WILL LIKELY BE A BETTER WIND EVENT SUNDAY MORNING AS CONTINUED
COLD AIR ADVECTION ALIGNS WITH THE NORTHEAST UPPER WIND SUPPORT AND
LAST BIT OF COLD AIR ADVECTION. THIS WILL BE A MORE TYPICAL WIND
EVENT PEAKING IN THE MORNING AND THEN DIMINISHING IN THE AFTERNOON.
MORE WIND ADVISORIES WILL LIKELY BE NEEDED AND AT THIS TIME CANNOT
RULE OUT THE POSSIBILITY OF A FEW LOW LEVEL WIND WARNINGS. AGAIN MAX
TEMPS WILL BE COOL PROBABLY WITHIN A DEGREE OF SATURDAYS VALUES.

.LONG TERM (MON-WED)…
GFS AND EC BOTH KEEP THE POS TILT LONG WAVE TROF IN PLACE THROUGH
TUESDAY. NEITHER BRING ANY IMPULSES THROUGH THE AREA DURING THE TIME
PERIOD AND THE FORECAST WILL BE PRETTY BLAND WITH CLEAR
SKIES…LOCAL MORNING LIGHT CANYON BREEZES…AND BELOW NORMAL MAX
AND MIN TEMPERATURES.

THE UPPER TROF FINALLY MOVES AWAY WEDNESDAY AND WILL ALLOW FOR A FEW
DEGREES OF WARMING.




The National Weather Service is predicting the following local surface conditions for Friday through Monday:

FRIDAY:
Sunny. Temperature: 50 degrees
Wind: Northeast 10 to 20 mph. Gusty.

SATURDAY:
Sunny, Temperature: 49 degrees
Wind: Northeast 10 to 15 mph. Increasing to 20. Gusty.

SUNDAY
Sunny, Temperature: 48 degrees
Wind: Northeast 15 to 20 mph.

MONDAY:
Sunny, Temperature: 50 degrees
Wind: Northeast 15 to 20 mph.

-Robert….