FXUS65 KLKN 252248
AFDLKN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ELKO NV
248 PM PST FRI DEC 25 2009

.SYNOPSIS...HIGH PRESSURE THROUGH SATURDAY NIGHT WILL KEEP SKIES 
CLEAR AND TEMPERATURES BITTERLY COLD OVERNIGHT. A SERIES OF LOW 
PRESSURE SYSTEM LATE THIS WEEKEND AND NEXT WILL WILL BRING A CHANCE 
OF PRECIPITATION AND CLOUD COVER WILL HELP MODERATE LOW
TEMPERATURES.

&&

.SHORT TERM...CURRENTLY...THE LONGWAVE PATTERN FEATURES AN
AMPLIFIED RIDGE ALONG THE WEST WITH A CLOSED LOW OVER THE GULF OF
ALASKA. THIS AREA OF HIGH PRESSURE WILL CONTINUE TO INFLUENCE THE
LKN CWA FOR THE REMAINDER OF TODAY AND SATURDAY...RESULTING IN
PREDOMINATELY CLEAR SKIES AND BITTERLY COLD TEMPERATURES DURING
THE NIGHT AND EARLY MORNINGS. EXPECT TEMPERATURES BELOW ZERO ACROSS
PORTIONS OF ELKO...WHITE PINE...LANDER AND EUREKA COUNTIES.
HOWEVER...ON THE HORIZON...A PACIFIC STORM WILL BE CLOSING IN ON
CALIFORNIA...BRINGING CLOUDS INTO THE REGION LATE SATURDAY AND
SUNDAY WHICH WILL REDUCE THE AMOUNT OF RADIATIONAL COOLING AT NIGHT.
THIS SYSTEM WILL GET SHEARED APART BY THE TERRAIN OF THE
SIERRA...ALTHOUGH THERE IS A SLIGHT CHANCE OF SHOWERS OVER
THE WESTERN PORTIONS OF THE LKN CWA ON SUNDAY...SIGNIFICANT
ACCUMULATIONS ARE NOT EXPECTED.

.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...SPLIT FLOW PATTERN TO 
START OF THE PERIOD WITH STRONG RIDGE OF HIGH PRESSURE JUST EAST OF 
THE FORECAST AREA AND LOW PRESSURE OFF THE COAST.  PATTERN 
TRANSITIONS TO A BROAD TROF WITH WEAK UPPER LOW FOR NEVADA BY 
MONDAY...SLIGHT CHANCE OF PRECIP MAINLY FOR NORTHERN NEVADA. THEN 
BACK TO HIGH PRESSURE FOR THE END OF THE WEEK. TRANSIENT SHORTWAVES 
EXPECTED TO PROPAGATE OVER THE FORECAST AREA...BEST POPS EXPECTED 
TUESDAY NIGHT AND WEDNESDAY MORNING AS UPPER 130KT JET SPILLS OVER 
THE RIDGE OVER THE FORECAST AREA ALONG WITH S/W TROF WITH BEST 
POSITIVE VORTICITY ADVECTION OVER NORTHERN NEVADA. 700MB TEMPS OF -8 
OR COLDER MEANS ANY PRECIP SHOULD COME DOWN AS SNOW...BEHIND THE 
SYSTEM 700MB TEMPS PLUMMET TO -15C ACROSS CENTRAL NEVADA. WARMER 
TEMPERATURES ARE EXPECTED FOR THE END OF THE WEEK AS HIGH PRESSURE 
BUILDS IN WITH WARMER TEMPS ALOFT.

&&

.AVIATION...WITH RIDGING IN PLACE...EXPECT LIGHT WINDS AND VFR 
CONDITIONS AT ALL TAF SITES. PATCHY FREEZING FOG MAY DEVELOP IN THE 
OVERNIGHT AND EARLY MORNING HOURS IN THE VICINITY OF WMC.

&&

.LKN WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

97/84/97