Flash Flood Warning 16, NWS Flagstaff, AZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF
245 AM MST SAT FEB 19 2005

.SYNOPSIS...A LOW PRESSURE SYSTEM OFF THE COAST OF CALIFORNIA WILL
BRING PERIODS OF RAIN AND SNOW TO ARIZONA THROUGH THE WEEKEND AND
INTO NEXT WEEK. SNOW LEVELS WILL LOWER TO NEAR 6000 FEET TODAY WITH
ACCUMULATING SNOW EXPECTED OVER THE HIGHER TERRAIN.

&&

.DISCUSSION...A BROAD TROUGH REMAINED ACROSS THE SOUTHWEST UNITED
STATES AND EASTERN PACIFIC THIS MORNING. AS A RESULT...A FETCH OF
MOISTURE CONTINUED TO MOVE ACROSS ARIZONA FROM THE PACIFIC. FAST
MOVING SHORT-WAVE DISTURBANCES IN THIS GENERAL FLOW WILL CONTINUE TO
CAUSE PERIODIC ENHANCEMENTS OF PRECIPITATION. ONE SUCH DISTURBANCE
WAS MOVING INTO CENTRAL ARIZONA THIS MORNING AND PROMISES TO BRING
WIDESPREAD RAIN AND SNOW TO THE AREA UNTIL AROUND NOON. THE SNOW
LEVEL WILL LOWER TO NEAR 6000 FEET BY AROUND NOON. EVEN AFTER THE
CURRENT DISTURBANCE PASSES EXPECT IT TO REMAIN SHOWERY AS THE AIR
MASS WILL REMAIN VERY MOIST AND UNSTABLE. YET ANOTHER DISTURBANCE
WILL MOVE ACROSS CENTRAL ARIZONA OVERNIGHT BRINGING ANOTHER ROUND
OF ENHANCED RAIN AND SNOW SHOWER ACTIVITY. THE SNOW LEVEL
OVERNIGHT WILL REMAIN AROUND 6000 FEET.

FOR THE DAY SUNDAY...EXPECT SOME SHOWER ACTIVITY BUT A STRENGTHENING
LOW OFF THE COAST OF CALIFORNIA WILL HELP TO BUILD A SHORT-WAVE
RIDGE ACROSS ARIZONA. THIS WILL STABILIZE THE AIR MASS AND HELP
LIMIT SHOWER ACTIVITY. THE RIDGE WILL BE SHORT-LIVED AS THE LOW OFF
THE CALIFORNIA COAST APPROACHES ARIZONA MONDAY NIGHT OR TUESDAY. THE SNOW
LEVEL IS EXPECTED TO BE IN THE 6000 TO 6500 FOOT RANGE WITH
SIGNIFICANT SNOW ACCUMULATION A POSSIBILITY OVER THE HIGHER TERRAIN
OF NORTHERN ARIZONA ON TUESDAY. WIDESPREAD RAIN WILL BE POSSIBLE OVER AREAS
SOUTH OF THE MOGOLLON RIM.

MCCOLLUM

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...FFA UNTIL SATURDAY EVENING FOR
ARIZONA ZONES 006/007/008/018/037/038.

SNOW ADVISORY UNTIL NOON MST SATURDAY FOR ARIZONA ZONES
004/006/007/015/016.

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
700 AM MST FRI FEB 18 2005

AZZ004>018-037>040-191400-
WESTERN MOGOLLON RIM-GRAND CANYON COUNTRY-YAVAPAI COUNTY MOUNTAINS-
YAVAPAI COUNTY VALLEYS AND BASINS-OAK CREEK AND SYCAMORE CANYONS-
MARBLE AND GLEN CANYONS-KAIBAB PLATEAU-COCONINO PLATEAU-
NORTHEAST PLATEAU AND MESAS HWY 264 NORTHWARD-
NORTHEAST PLATEAU AND MESAS SOUTH OF HWY 264-
CHINLE VALLEY-CHUSKA MOUNTAINS AND DEFIANCE PLATEAU-
BLACK MESA AREA-LITTLE COLORADO RIVER VALLEY IN COCONINO COUNTY-
LITTLE COLORADO RIVER VALLEY IN NAVAJO COUNTY-
LITTLE COLORADO RIVER VALLEY IN APACHE COUNTY-
EASTERN MOGOLLON RIM-WHITE MOUNTAINS-NORTHERN GILA COUNTY-
700 AM MST FRI FEB 18 2005

THIS HAZARDOUS WEATHER OUTLOOK IS FOR APACHE...COCONINO...NORTHERN
GILA...NAVAJO...AND YAVAPAI COUNTIES IN NORTHERN ARIZONA.

.DAY ONE...TODAY

A LOW PRESSURE SYSTEM NEAR THE SOUTHWEST UNITED STATES WILL BRING
SIGNIFICANT PRECIPITATION TO NORTHERN ARIZONA TODAY. RAINFALL
AMOUNTS OF ONE TO TWO INCHES CAN BE EXPECTED WITH LOCALLY HIGHER
AMOUNTS POSSIBLE. THIS RAINFALL COULD RESULT IN FLOODING ACROSS
PORTIONS OF ARIZONA TODAY. A FLASH FLOOD WATCH HAS BEEN ISSUED. SEE
PHXFFAFGZ FOR DETAILS.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

LOW PRESSURE WILL CONTINUE TO BRING SIGNIFICANT PRECIPITATION TO
NORTHERN ARIZONA ON SATURDAY AND A FLASH FLOOD WATCH WILL REMAIN IN
EFFECT THROUGH SATURDAY EVENING.

SNOW LEVELS WILL FALL TO AROUND 6500 FEET EARLY SATURDAY MORNING.
MODERATE SNOWFALL ACCUMULATIONS ARE LIKELY AT THE HIGHER ELEVATIONS
AND A SNOW ADVISORY MAY BE NECESSARY.

.SPOTTER INFORMATION STATEMENT...

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