Wildfire in Arizona, August 8 to 17, 2015

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
1000 AM PDT SAT AUG 8 2015

.SYNOPSIS...MAINLY DRY AND QUIET CONDITIONS ARE EXPECTED ACROSS THE
REGION THIS WEEKEND. NEXT WEEK HIGH PRESSURE OVER THE SOUTHWEST
WILL BRING SEASONABLY HOT TEMPERATURES AND OPEN THE DOOR FOR MONSOON
MOISTURE DURING THE MIDDLE OF THE WEEK. DURING THIS TIME FRAME IT
APPEARS THE BEST CHANCES FOR THUNDERSTORMS WILL BE FROM ROUGHLY LAS
VEGAS EAST.
&&

.UPDATE...THE LATEST OBSERVATIONS AND MODEL GUIDANCE SUPPORT THE
TRENDS DETAILED IN THE PREVIOUS DISCUSSION. NO CHANGES NEEDED.
&&

.PREV DISCUSSION...
153 AM PDT SAT AUG 8 2015

.SHORT TERM...TODAY THROUGH MONDAY NIGHT.

CONVECTION HAS PUSHED EAST OF THE AREA AND MOSTLY DRY CONDITIONS ARE
EXPECTED TO PREVAIL INTO EARLY NEXT WEEK. HI-RES GUIDANCE DOES
INDICATE A SLIGHT CHANCE OF SHOWERS OVER THE SIERRA TODAY AND A
MENTION OF THUNDERSTORMS WAS KEPT IN THE FORECAST THERE. THE ONLY
OTHER AREA OF CONCERN IS THE EASTERN FRINGE OF MOHAVE COUNTY. THE
MOISTURE BOUNDARY THAT WAS DRAPED ACROSS OUR CWA YESTERDAY HAS
PUSHED EAST AND IS EXPECTED TO LINGER IN THE VICINITY OF THE EASTERN
MOHAVE COUNTY LINE. HAVE LEFT OUT MENTION OF PRECIP FOR NOW...BUT
THIS WILL NEED TO BE MONITORED THROUGH THE DAY. IN FACT...THIS
SCENARIO IS EXPECTED TO PLAY OUT SIMILARLY FOR SUNDAY AND
MONDAY...BUT HAVE KEPT ANY MENTION OF WEATHER OUT OF THE FORECAST
FOR THOSE DAYS AT THIS TIME. THE ONLY APPRECIABLE DIFFERENCE BETWEEN
THE DAYS WILL LIKELY BE GRADUALLY WARMING TEMPERATURES AND SLIGHTLY
ENHANCED SOUTHERLY BREEZES ON SUNDAY AND MONDAY.

.LONG TERM...TUESDAY THROUGH FRIDAY.

MODELS AGREE IN PRINCIPLE ON THE OVERALL PATTERN THROUGH THE PERIOD
WITH A FEW MINOR DIFFERENCES IN DETAILS. PICKING UP TUESDAY
MORNING...OUR CWA IS UNDER SOUTH-SOUTHWEST FLOW BETWEEN A STRONG
TROUGH ALONG 130W AND STRONG RIDGING OVER THE HIGH PLAINS AND
ROCKIES. THE OVERALL PATTERN MOVES VERY LITTLE THROUGH
WEDNESDAY...THEN THURSDAY THE TROUGH WEAKENS AND MOVES INTO THE
PACIFIC NORTHWEST COAST...ALLOWING THE RIDGE TO BULGE WESTWARD. AS
THE TROUGH WEAKENS FURTHER ON FRIDAY...THE RIDGE SLIDES WEST TO NEAR
THE FOUR CORNERS. THE PRIMARY DETAIL PROBLEM IS MOISTURE. THE ECMWF
STARTS OUT TUESDAY SHOWING MONSOON MOISTURE CONFINED EAST OF OUR
AREA...WHILE THE GFS SHOWS IT ALREADY INTO MOHAVE COUNTY. THAT TREND
CONTINUES ON WEDNESDAY...WITH THE GFS AGGRESSIVELY SPREADING
MOISTURE NEARLY CWA-WIDE WHILE THE ECMWF KEEPS IT CONFINED TO THE
EASTERN ZONES. INHERITED GRIDS LOOKED A LOT LIKE THE ECMWF
SOLUTION...AND CHOSE TO NUDGE THEM A LITTLE MORE TOWARD A
COMPROMISE...BUT NO RADICAL CHANGES. TEMPERATURES WILL BE A PROBLEM
FOR THE SAME REASON. GFS MOS HIGH TEMPS ARE RUNNING SEVERAL DEGREES
LOWER THAN ECMWF MOS THROUGH THE PERIOD DUE TO THE MOISTURE
DIFFERENCES. STUCK WITH PREVIOUS FORECASTS...WHICH WERE A COMPROMISE
SOLUTION OF ROUGHLY TWO THIRDS GFS AND ONE THIRD ECMWF.
&&

.AVIATION...FOR MCCARRAN...MOSTLY CLEAR AND QUIET CONDITIONS ARE
EXPECTED THIS WEEKEND WITH RELATIVELY LIGHT WINDS OUT OF THE
SOUTHWEST OVERNIGHT AND FAVORING AN EASTERLY DIRECTION DURING THE
AFTERNOON.

FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...MOSTLY CLEAR AND QUIET CONDITIONS ARE EXPECTED THIS
WEEKEND WITH WINDS FAVORING TYPICAL DIURNAL TRENDS TODAY. SOUTHERLY
WINDS WILL BECOME ENHANCED ON SUNDAY.
&&

.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&

SHORT TERM/AVIATION...WOLCOTT
LONG TERM.............MORGAN

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