FXUS65 KVEF 250455 
  AFDVEF 
   
  AREA FORECAST DISCUSSIONAREA FORECAST DISCUSSION
This National Weather Service
product is intended to provide a
well-reasoned discussion of the
meteorological thinking which went
into the preparation of the Zone
Forecast Product. The forecaster
will try to focus on the most
particular challenges of the
forecast. The text will be written
in plain language or in proper
contractions. At the end of the
discussion, there will be a list of
all advisor...
Click for More... 
  NATIONAL WEATHER SERVICENATIONAL WEATHER SERVICE
An agency of the Federal Government
within the Department of Commerce,
National Oceanic and Atmospheric
Click for More... LAS VEGAS NV 
  855 PM PSTPST
Pacific Standard Time
Click for More... TUE NOV 24 2009 
   
  .SYNOPSIS...GUSTY NORTH WINDS DOWN THE COLORADO RIVER VALLEY WILL  
  CONTINUE THROUGH WEDNESDAY...WITH QUIET WEATHER OVER THE REMAINDER  
  OF THE AREA. TEMPERATURES WILL BE A FEW DEGREES ABOVE NORMAL  
  WEDNESDAY AND THANKSGIVING DAY...THEN A COLD FRONTCOLD FRONT
A zone separating two air masses,
of which the cooler, denser mass is
advancing and replacing the warmer.
Click for More... WILL BRING BREEZY  
  AND MUCH COOLER WEATHER OVER THE WEEKEND. 
  && 
   
  .UPDATE...THE 00Z GFSGFS
Global Forecast System - One of the
operational forecast models run at
NCEP. The GFS is run four times
daily, with forecast output out to
384 hours.
Click for More... AND NAMNAM
The operational North Amercian Meso
(NAM, formerly Eta, currently the
same as the WRF) is run four times
per day (00,06,12,18Z), all cycles
run to 84-h.
Click for More... SOLUTIONS SHOW LITTLE THROUGH  
  FRIDAY FROM THE FORECAST TRENDS DETAILED BELOW. NO UPDATE 
  PLANNED. 
  && 
   
  .PREV DISCUSSION.../213 PM PSTPST
Pacific Standard Time
Click for More... TUE NOV 24 2009/ 
   
  .SHORT TERM...SATELLITE SHOWS THIN CIRRUSCIRRUS
(abbrev. CI) High-level clouds
(16,000 feet or higher), composed
of ice crystals and appearing in
the form of white, delicate
filaments or white or mostly white
patches or narrow bands. Cirrus
clouds typically have a fibrous or
hairlike appearance, and often are
semi-transparent. Thunderstorm
anvils are a form of cirrus cloud,
but most cirrus clouds are not
associated with thunderstorms.
Click for More... OVER MUCH OF OUR  
  CWFACWFA
County Warning and Forecast Area
Click for More......WITH A PATCH OF THICKER CIRRUSCIRRUS
(abbrev. CI) High-level clouds
(16,000 feet or higher), composed
of ice crystals and appearing in
the form of white, delicate
filaments or white or mostly white
patches or narrow bands. Cirrus
clouds typically have a fibrous or
hairlike appearance, and often are
semi-transparent. Thunderstorm
anvils are a form of cirrus cloud,
but most cirrus clouds are not
associated with thunderstorms.
Click for More... INVADING FROM THE NORTH.  
  SURFACE OBSOBS
Observation(s)
Click for More... SHOW LOCALLY GUSTY NORTH WINDS CONTINUING...ESPECIALLY  
  DOWN THE COLORADO RIVER. THIS WILL BE THE MAIN FORECAST PROBLEM FOR  
  THE SHORT TERM. PRESSURE GRADIENTGRADIENT
(abbrev. GRAD) A rate of change
with respect to distance of a
variable quantity, as temperature
or pressure, in the direction of
maximum change.
Click for More... BETWEEN KELY AND KEED IS STILL  
  11.9 MBMB
Millibar
Click for More... AS OF 2 PM...COMPARED TO MODEL FORECASTS YESTERDAY OF ABOUT  
  9 MBMB
Millibar
Click for More.... THE MODELS STILL SHOW GRADIENTS WEAKENING TOMORROW...BUT AM  
  SUSPICIOUS OF THAT TREND BASED ON WHAT HAPPENED TODAY. SUSPECT THE  
  MODELS MAY NOT BE HANDLING THE MAINTENANCE/STRENGTHENING OF SURFACE  
  HIGH PRESSURE IN THE GREAT BASINBASIN
An area having a common outlet for
its surface runoff. Also called a
"Drainage Basin."
Click for More... BY THE VERY COLD NIGHTTIME  
  TEMPERATURES THERE. THUS...MANUALLY INCREASED WIND FORECASTS IN THE  
  BULLHEAD CITY AREA FOR TONIGHT AND TOMORROW. WINDS TODAY ARE RIGHT  
  ON THE BORDERLINE OF LAKE WIND ADVISORYWIND ADVISORY
Sustained winds 30 mph and greater
or frequent wind gusts 35 mph or
greater. These thresholds are
slightly higher for desert and
mountain areas.
Click for More... CRITERIA FOR THE SECOND DAY  
  IN A ROW...BUT THE NATIONAL PARK SERVICE REPORTS NO PROBLEMS...SO  
  WILL AGAIN FORGO AN ADVISORYADVISORY
Highlights special weather
conditions that are less serious
than a warning. They are for events
that may cause significant
inconvenience, and if caution is
not exercised, it could lead to
situations that may threaten life
and/or property.
Click for More.... CONDITIONS WILL PROBABLY BE BORDERLINE  
  AGAIN TOMORROW BEFORE THE WINDS FINALLY SUBSIDE A BIT ON  
  THANKSGIVING DAY. AS THE SHORT TERM COMES TO AN END THURSDAY  
  NIGHT...ATTENTION SHIFTS WEST TO A PACIFIC STORMSTORM
Any disturbed state of the
atmosphere, especially affecting
the Earth's surface, and strongly
implying destructive and otherwise
unpleasant weather. Storms range in
scale from tornadoes and
thunderstorms to tropical cyclones
to synoptic-scale extratropical
cyclones.
Click for More... APPROACHING THE  
  COAST. SENSIBLE WEATHER EFFECTS SHOULD BE MINIMAL THROUGH THURSDAY  
  NIGHT...WITH PRESSURE GRADIENTS BEGINNING TO REVERSE AS THE GREAT  
  BASINBASIN
An area having a common outlet for
its surface runoff. Also called a
"Drainage Basin."
Click for More... HIGH GETS ERODED/KICKED TO THE EAST. 
   
  .LONG TERM...AFTER SOME BETTER MODEL CONTINUITY DURING THE SECOND  
  HALF OF THE HOLIDAY WEEKEND...12Z SOLUTIONS DECIDED TO DIVERGE  
  AGAIN. MODELS ARE HAVING A DIFFICULT TIME WITH EXACT PLACEMENT AND  
  DEPTH OF TROUGHTROUGH
An elongated area of relatively low
atmospheric pressure, usually not
associated with a closed
circulation, and thus used to
distinguish from a closed low. The
opposite of ridge.
Click for More... AS IT DIGS TO OUR EAST OVER THE FOUR CORNER STATES  
  THIS WEEKEND. NOT TO BORE EVERYONE WITH EXACT DETAILS LAST NIGHT 06Z  
  AND THE NEW 18Z DGEX ARE A GOOD COMPROMISE BETWEEN THE DEEPER ECMWFECMWF
European Center for Medium-Range
Weather Forecasts. Operational
references in forecast discussions
typically refer to the ECMWF's
medium-range numerical forecast
model, which runs out to 10 days.
Click for More...  
  AND THE WEAKER/MORE PROGRESSIVE GFS/GEM. AS TROUGHTROUGH
An elongated area of relatively low
atmospheric pressure, usually not
associated with a closed
circulation, and thus used to
distinguish from a closed low. The
opposite of ridge.
Click for More... SLIDES ACROSS  
  FRIDAY NIGHT/SATURDAY THERE IS A SLIGHT CHANCE OF SHOWERS OVER THE  
  HIGHER TERRAIN OF SOUTHERN NEVADA AND NORTHWEST ARIZONA. ON THE  
  BACKSIDE OF THE TROUGHTROUGH
An elongated area of relatively low
atmospheric pressure, usually not
associated with a closed
circulation, and thus used to
distinguish from a closed low. The
opposite of ridge.
Click for More......NORTH WINDS WILL USHER IN COOLER  
  TEMPERATURES FOR THE WEEKEND. THE NORTH WIND WILL BE STRONGEST ON  
  SATURDAY AND SUNDAY WITH BREEZY CONDITIONS DOWN THE COLORADO RIVER  
  VALLEY. WINDS WILL DECREASE AND TEMPERATURES REBOUND EARLY NEXT WEEK  
  AS RIDGERIDGE
An elongated area of relatively
high atmospheric pressure; the
opposite of trough.
Click for More... BUILDS OVER THE SOUTHWEST STATES. 
  && 
   
  .AVIATION...FOR MCCARRAN...FEW-SCT CIRRUSCIRRUS
(abbrev. CI) High-level clouds
(16,000 feet or higher), composed
of ice crystals and appearing in
the form of white, delicate
filaments or white or mostly white
patches or narrow bands. Cirrus
clouds typically have a fibrous or
hairlike appearance, and often are
semi-transparent. Thunderstorm
anvils are a form of cirrus cloud,
but most cirrus clouds are not
associated with thunderstorms.
Click for More... THROUGH WEDNESDAY. LIGHT  
  WEST TO NORTHWEST WIND OVERNIGHT. NORTHEAST WIND LESS THAN 10 KTSKTS
Knots
Click for More...  
  WILL DEVELOP AFTAFT
After
Click for More... 17Z WEDNESDAY.  
   
  FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST  
  CALIFORNIA...NORTH TO NORTHEAST WINDS WILL CONTINUE INTO THE EARLY  
  EVENING THEN BECOME DOWNVALLEY LESS THAN 7 KTSKTS
Knots
Click for More... THE REST OF TONIGHT.  
  NORTH WINDS OF 15-25KTS WILL AGAIN DEVELOP DOWN THE LOWER COLORADO  
  RIVER VALLEY AFTAFT
After
Click for More... 16Z WEDNESDAY IMPACTING THE AREA BETWEEN KIFP AND  
  KEED. FEW-SCT CIRRUSCIRRUS
(abbrev. CI) High-level clouds
(16,000 feet or higher), composed
of ice crystals and appearing in
the form of white, delicate
filaments or white or mostly white
patches or narrow bands. Cirrus
clouds typically have a fibrous or
hairlike appearance, and often are
semi-transparent. Thunderstorm
anvils are a form of cirrus cloud,
but most cirrus clouds are not
associated with thunderstorms.
Click for More... THROUGH WEDNESDAY.  
  && 
   
  .VEF WATCHES/WARNINGS/ADVISORIES... 
  NV...NONE. 
  AZ...NONE. 
  CACA
California
Click for More......NONE. 
  && 
   
  
 
   
  ADAIR/MORGAN/PIERCE 
   
  HTTP://WEATHER.GOV/LASVEGAS