Flash Flood Warning 20, NWS Flagstaff, AZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
950 AM MST TUE JUL 26 2005

.SYNOPSIS...DRIER AIR ALOFT HAS MOVED INTO NORTHERN ARIZONA UNDER A
NORTHWESTERLY FLOW AND THIS WILL BRING A DRYING TREND TODAY AND
WEDNESDAY...ESPECIALLY NORTH OF FLAGSTAFF. BY THURSDAY INTO
FRIDAY...MOISTURE WILL INCREASE ACROSS THE STATE AS HIGH PRESSURE ALOFT
RE-ESTABLISHES EAST OF ARIZONA...BRINGING AN INCREASING CHANCE FOR
SHOWERS AND THUNDERSTORMS. TEMPERATURES WILL REMAIN NEAR SEASONAL
LEVELS.

&&

.DISCUSSION...CONVECTION ALREADY STARTING OVER SAN FRANCISCO PEAKS
AND IN YAVAPAI COUNTY AT THIS TIME. 12Z KFGZ SOUNDING FROM THIS
MORNING SHOWING THE DRIER WEST TO NORTHWEST FLOW BEGINNING TO TAKE SHAPE.
HOWEVER...SOUNDING INDICATES DRYING IS MAINLY ABOVE THE 500MB LEVEL.
BELOW 500MB THERE IS ENOUGH MOISTURE AROUND TO INITIATE
CONVECTION...PER LOOKING OUT THE WINDOW. DPI SOUNDER SHOWS BETWEEN
1.0 AND 1.2 INCHES OF PW ACROSS THE SOUTHERN SECTIONS OF THE CWA.
STORMS WILL FORM OVER THE HIGH COUNTRY AND BEGIN TO MOVE EAST TO
SOUTHEAST. BASED ON THIS...CURRENT THINKING NOW WILL BE TO INCREASE
THE POP COVERAGE ACROSS THE RIM AND SOUTHERN CWA TO THE 40-50
PERCENT RANGE...WHILE LEAVING THE NORTHERN PORTIONS ALONE. CK

&&

.AVIATION...FOR 18Z PACKAGE...RAPID CONVECTIVE DEVELOPMENT IS
EXPECTED THIS MORNING ALONG AND SOUTH OF THE MOGOLLON RIM. CLOUD
BASES WILL BE AROUND 4-6K FEET AGL WITH CBS LOWERING CEILINGS TO
UNDER 4K FEET AGL. EXPECTING NEAR 50 PERCENT COVERAGE OF SHOWERS AND
THUNDERSTORMS ALONG AND SOUTH OF RIM WITH 20 PERCENT OR LESS NORTH
AND NORTHEAST OF THE RIM WHERE DRIER AIR EXISTS. MICRO-BURST WINDS
OF 40-45 MPH POSSIBLE UNDER STRONGER STORMS TODAY...WITH ISOLATED
TORRENTIAL RAIN AND MAINLY SMALL HAIL. AVIATION DISCUSSION NOT
UPDATED FOR AMENDMENTS. PETERSON

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1003 AM MST TUE JUL 26 2005

AZZ004>018-037>040-270700-
BLACK MESA AREA-CHINLE VALLEY-CHUSKA MOUNTAINS AND DEFIANCE PLATEAU-
COCONINO PLATEAU-EASTERN MOGOLLON RIM-GRAND CANYON COUNTRY-
KAIBAB PLATEAU-LITTLE COLORADO RVR VLY IN APACHE CO-
LITTLE COLORADO RVR VLY IN COCONINO CO-
LITTLE COLORADO RVR VLY IN NAVAJO CO-MARBLE AND GLEN CANYONS-
NORTHEAST PLATEAU AND MESAS SOUTH OF 264-
NORTHEAST PLATEAUS AND MESAS 264 NORTH-NORTHERN GILA COUNTY-
OAK CREEK AND SYCAMORE CANYONS-WESTERN MOGOLLON RIM-WHITE MOUNTAINS-
YAVAPAI COUNTY MOUNTAINS-YAVAPAI COUNTY VALLEYS AND BASINS-
1003 AM MST TUE JUL 26 2005

THIS HAZARDOUS WEATHER OUTLOOK IS FOR...

.DAY ONE...TODAY

NORTHWEST FLOW WILL BRING DRIER AIR INTO THE NORTHERN
PORTIONS OF NORTHERN ARIZONA TODAY. THIS SHOULD LIMITED AREAL
COVERAGE OF STORMS ALONG A LINE NORTH FROM THE GRAND CANYON EAST TO
CHINLE. COVERAGE WILL INCREASE SOUTH OF THIS LINE...ESPECIALLY OVER
THE SOUTHERN PORTIONS OF ARIZONA. SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO FORM OVER YAVAPAI AND NORTHERN GILA
COUNTIES AND THE WHITE MOUNTAINS AROUND 10 AM MST TO 11 AM MST...AND
IT IS EXPECTED THESE WILL BE THE FAVORED LOCATIONS FOR MORE
WIDESPREAD ACTIVITY. STORMS WILL BE MOVING TO THE EAST AND SOUTHEAST
THIS AFTERNOON AND ARE CAPABLE OF PRODUCING POCKETS OF HEAVY RAIN
AND WIND GUSTS TO 45 MPH.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

DRIER NORTHWEST FLOW WILL CONTINUE INTO WEDNESDAY...LIMITING
CHANCES FOR THUNDERSTORM DEVELOPMENT TO ONLY THE HIGH TERRAIN
AREAS...INCLUDING NORTHERN GILA COUNTY. BY THURSDAY...SOUTHEAST FLOW
WILL MARK A RETURN TO MONSOONAL MOISTURE AND WILL INCREASE CHANCES
OF THUNDERSTORMS FOR A MAJORITY OF NORTHERN ARIZONA.

.SPOTTER INFORMATION STATEMENT...

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