Flash Flood Warning 12, NWS Flagstaff, AZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
815 PM MST MON AUG 3 2008

.SYNOPSIS...EXPECT INCREASED CHANCES FOR AFTERNOON AND EVENING
THUNDERSTORMS THROUGH THE WORK WEEK WITH DAYTIME TEMPERATURES
HOVERING NEAR AVERAGE FOR THIS TIME OF YEAR AS A MOIST AIRMASS
CONTINUES TO SIT OVER NORTHERN ARIZONA.

&&

.DISCUSSION...ANOTHER DAY OF SCATTERED SHOWERS AND THUNDERSTORMS
FREQUENTED NORTHERN ARIZONA TODAY. FROM A LOOK AT THE STORM TOTAL
PRECIPITATION PRODUCT...MOST OF THE RAIN FALL OVER WESTERN COCONINO
COUNTY WITH SOME LIGHTER AMOUNTS SEEN MORE TO THE SOUTH OVER
NORTHERN GILA COUNTY. ONE FLASH FLOOD WARNING WAS ISSUED EARLIER FOR
THE LANE 2 BURN AREA...BUT OTHERWISE PRETTY QUIET.

SURFACE DEWPOINTS ARE GENERALLY IN THE 50S ACROSS ALL SITES THIS
EVENING AS A MOIST AIR MASS SITS ATOP THE STATE. THIS EVENINGS
SOUNDING CHECKS IN AT ALMOST AN INCH OF PRECIPITABLE WATER.
SATELLITE IMAGERY SHOWS MAINLY MOSTLY CLOUDY SKIES OVER THE
NORTHLAND WITH SOME CLEARING OVER PHOENIXS AND TUCSONS COUNTY
WARNING AREA.

HAVE UPDATED POP AND ASSOCIATED GRIDS EARLIER THIS EVENING TO
REFLECT HIGHER CONVECTIVE ACTIVITY OVER THE WESTERN PORTIONS OF THE
FORECAST AREA...AS WELL AS FOR THE LITTLE COLORADO RIVER VALLEY
NORTH TO WINDOW ROCK. LOOKS LIKE THE ACTIVITY OVER THE LCR IS
STARTING TO WEAKEN A BIT PER LATEST RADAR TRENDS...BUT WILL KEEP AN
EYE ON IT AND UPDATE FURTHER IF NECESSARY.

.PREVIOUS DISCUSSION (230 PM MST)...CONVECTION BEGAN OVER HIGHER
TERRAIN LEFT CLOUD-FREE EARLIER TODAY. AT THIS POINT...NONE OF THE
STORMS HAS BEEN SEVERE...THOUGH THEY ARE PRODUCING APPRECIABLE
RAINFALL /AS MUCH AS 1.3 INCHES STORM TOTAL PRECIPITATION/.

AT 500 MB...A RIDGE OF HIGH PRESSURE STRETCHES ACROSS THE SOUTHERLY
LATITUDES OF THE LOWER 48 STATES. THE RIDGE AXIS REACHES FROM THE
MISSOURI-ARKANSAS BORDER WESTWARD THROUGH THE FOUR CORNERS. THIS
POSITIONING PLACES NORTHERN ARIZONA IN A FAVORABLE LOCATION FOR
CONTINUED MOISTURE INFLUX. AND THIS IS JUST WHAT MODELS ARE
INDICATING THROUGH THE FORECAST PERIOD. THE ONLY EXCEPTION MAY BE
LATE WEDNESDAY INTO THURSDAY WHEN MODELS INDICATE SLIGHTLY DRIER AIR
TRANSITING NORTHERN ARIZONA FROM EAST TO WEST. AREAL COVERAGE OF
STORMS WILL VARY FROM DAY TO DAY DEPENDING TO A CONSIDERABLE EXTENT
ON WHICH LOCATIONS CAN WARM UP MOST QUICKLY TO TRIGGER CONVECTION.
AREAS WHERE MORNING CLOUD COVER PREVENTS SURFACE HEATING OR
CLOUD-FREE AREAS WHERE INSOLATION IS FIRST PUT TO USE FOR
EVAPORATION OF EARLIER PRECIPITATION WILL LAG BEHIND IN STORM
DEVELOPMENT.
&&

.AVIATION...FOR THE 06Z PACKAGE...ISOLATED TO WIDELY SCATTERED
SHOWERS WITH EMBEDDED THUNDERSTORMS ARE EXPECTED TO SLOWLY DIMINISH
THIS EVENING ACROSS CENTRAL ARIZONA WITH MVFR/IFR CONDITIONS IN
THESE SHOWERS AND STORMS. WITH ABUNDANT MOISTURE REMAINING OVER THE
AREA...ANOTHER ROUND OF THUNDERSTORMS IS EXPECTED AFT 18Z TUESDAY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.
&&

.FIRE WEATHER...SEE FIRE WEATHER FORECAST (FWFFGZ) FOR DISCUSSION OF
DAYS 1 AND 2.

THURSDAY THROUGH SATURDAY...EXPECT ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS EACH AFTERNOON AND EVENING.
&&

PUBLIC.............42
AVIATION/FIRE WX...42

VISIT WEATHER.GOV/FLAGSTAFF FOR NORTHERN ARIZONA WEATHER INFORMATION.

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
948 AM MST MON AUG 4 2008

AZZ004>018-037>040-050800-
KAIBAB PLATEAU-MARBLE AND GLEN CANYONS-GRAND CANYON COUNTRY-
COCONINO PLATEAU-YAVAPAI COUNTY MOUNTAINS-
NORTHEAST PLATEAUS AND MESAS HWY 264 NORTHWARD-CHINLE VALLEY-
CHUSKA MOUNTAINS AND DEFIANCE PLATEAU-
LITTLE COLORADO RIVER VALLEY IN COCONINO COUNTY-
LITTLE COLORADO RIVER VALLEY IN NAVAJO COUNTY-
LITTLE COLORADO RIVER VALLEY IN APACHE COUNTY-
WESTERN MOGOLLON RIM-EASTERN MOGOLLON RIM-WHITE MOUNTAINS-
NORTHERN GILA COUNTY-YAVAPAI COUNTY VALLEYS AND BASINS-
OAK CREEK AND SYCAMORE CANYONS-BLACK MESA AREA-
NORTHEAST PLATEAUS AND MESAS SOUTH OF HWY 264-
948 AM MST MON AUG 4 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EAST CENTRAL
ARIZONA...NORTH CENTRAL ARIZONA...NORTHEAST ARIZONA AND WEST
CENTRAL ARIZONA.

.DAY ONE...TODAY AND TONIGHT
EXPECT SCATTERED RAIN SHOWERS AND THUNDERSTORMS TO DEVELOP BY
EARLY- TO MID-AFTERNOON OVER MOST HIGHER TERRAIN LOCATIONS. MOST
FAVORABLE CONDITIONS EXIST OVER THE EASTERN MOGOLLON RIM...IN THE
WHITE MOUNTAINS...AND OVER NORTHEASTERN GILA COUNTY. STORM
MOVEMENT WILL BE RATHER SLOW AND TOWARD THE WEST-NORTHWEST. THE
GREATEST HAZARD FROM TODAYS STORMS WILL BE THE AMOUNT OF WATER
PRODUCED BY HEAVILY-PRECIPITATING...SLOW-MOVING STORMS. EXPECT
ACTIVITY TO DIE OFF WITHIN A COUPLE OF HOURS AFTER SUNSET.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY
EXPECT CONTINUED CHANCES FOR DAILY AFTERNOON AND EVENING
THUNDERSTORMS.

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

HOWARD