Flash Flood Warning 10, NWS Flagstaff, AZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
910 AM MST THU SEP 10 2009

.SYNOPSIS...LINGERING MONSOON MOISTURE WILL ALLOW FOR A CONTINUED
CHANCE OF SHOWERS AND THUNDERSTORMS THE NEXT SEVERAL DAYS. NEAR
NORMAL TEMPERATURES AND LIGHT WINDS ARE EXPECTED.

&&

.DISCUSSION...AN UPPER LEVEL LOW REMAINS OVER NORTH CENTRAL AZ THIS
MORNING PRODUCING SCATTERED AND MAINLY LIGHT SHOWERS. THIS FEATURE
IS EXPECTED TO BEGIN MOVING SOUTHEASTWARD AND SHOULD BEGIN TO
PROMOTE NORTHERLY FLOW OVER MUCH OF NORTHERN AZ TOWARD LATE
AFTERNOON OR EVENING. THIS FEATURE SHOULD BRING GOOD COVERAGE OF
SHOWERS AND THUNDERSTORMS TO MUCH OF NORTHERN AZ TODAY AS IT
INTERACTS WITH A MOIST AND UNSTABLE AIRMASS ALREADY IN PLACE OVER
THE REGION. STORM COVERAGE WILL LIKELY DEVELOP LATE IN THE MORNING
OR EARLY AFTERNOON OVER THE HIGHER TERRAIN AND SPREAD SOUTHWARD INTO
LOWER ELEVATIONS LATE IN THE LATE AFTERNOON AND EVENING. FORECAST
PACKAGE HAS BEEN UPDATED FOR COVERAGE OF MORNING SHOWER ACTIVITY AND
CLOUD COVER.

.PREVIOUS DISCUSSION/418 AM MST/...WIDELY SCATTERED AND GENERALLY
LIGHT SHOWERS ARE CONTINUING EARLY THIS MORNING MAINLY NORTH OF I-40
IN NORTHERN ARIZONA. FOR THE REST OF TODAY...THE PERSISTENTLY MOIST
AIR MASS WILL ALLOW THUNDERSTORM DEVELOPMENT ACROSS THE NORTHLAND
YET AGAIN...WITH THE BEST CHANCES ACROSS THE HIGHER TERRAIN FROM
FLAGSTAFF EASTWARD.

A WEAK FLOW PATTERN WILL ALLOW FOR THIS MOISTURE TO CONTINUE FOR THE
FOLLOWING SEVERAL DAYS...WITH NO STRONG INDICATION FOR THE UNSETTLED
WEATHER ENDING UNTIL PERHAPS THE MIDDLE OF NEXT WEEK. DAYTIME TEMPS
NEAR SEASONAL NORMALS ARE ANTICIPATED.

&&

.AVIATION...FOR THE 18Z PACKAGE...MOST AREAS WILL SEE SCATTERED TO
BROKEN SKY CONDITIONS THROUGH THE DAY AND INTO THE EARLY EVENING
HOURS. IN ADDITION...WIDELY SCATTERED SHOWERS AND THUNDERSTORMS CAN
BE EXPECTED THROUGH THE EARLY EVENING HOURS...WITH ISOLATED MVFR
CONDITIONS IN THE HEAVIEST SHOWERS. SKIES WILL PARTIALLY CLEAR WITH
VFR CONDITIONS OVERNIGHT. AVIATION DISCUSSION NOT UPDATED FOR
AMENDMENTS.

&&

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

&&

PUBLIC.......................ONTON
AVIATION/FIRE WEATHER........MCCOLLUM

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

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1008 AM MST THU SEP 10 2009

AZZ004>018-037>040-110830-
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-
1008 AM MST THU SEP 10 2009

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

LINGERING MONSOON MOISTURE WILL RESULT IN SCATTERED SHOWERS AND
THUNDERSTORMS ACROSS MOST OF NORTHERN ARIZONA TODAY. LOCALIZED
FLOODING AND HAIL WILL BE THE MAIN THREAT FROM THE STRONGEST
STORMS TODAY.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

MOISTURE WILL LINGER OVER THE AREA FOR THE NEXT SEVERAL DAYS.
ISOLATED TO SCATTERED THUNDERSTORMS WILL DEVELOP EACH
DAY...PRIMARILY DURING THE AFTERNOON AND EVENING...WITH SUBTLE
DAY TO DAY CHANGES IN WEATHER IMPACTS. LOCALIZED AREAS OF HEAVY
RAINFALL AND FLASH FLOODING ARE POSSIBLE EACH DAY.

.SPOTTER INFORMATION STATEMENT...

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