Severe Thunderstorm Warning 285, NWS Flagstaff, AZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
930 AM MST FRI OCT 06 2006

.SYNOPSIS...A STRONG STORM SYSTEM WILL CONTINUE TO PRODUCE NUMEROUS
SHOWERS AND THUNDERSTORMS WITH HEAVY RAIN AT TIMES TODAY. THIS
SYSTEM WILL ALSO BRING STRONG AND GUSTY SOUTH WINDS. SLIGHTLY DRIER
AIR WILL MOVE OVER ARIZONA TONIGHT WITH A DOWN TREND TO SHOWERS AND
THUNDERSTORMS. UNSETTLED WEATHER WILL STILL PERSIST THROUGH THE
WEEKEND AND INTO EARLY NEXT WEEK.

&&

.DISCUSSION...NORTHERN ARIZONA WILL REMAIN UNDER A VERY STRONG MOIST
SOUTHERLY FLOW THROUGH THIS EVENING. DEWPOINT TEMPERATURES ACROSS
NORTHERN AZ ARE GENERALLY IN THE UPPER 40S TO LOW 50S AND A DEEP
NEARLY SATURATED AND UNSTABLE SOUNDING. A COLD FRONT OVER THE
WESTERN COLORADO RIVER THAT IS MOVING EASTWARD WITH STRONG DYNAMIC
UPLIFT WILL CONTINUE TO PRODUCE NUMEROUS THUNDERSTORMS ACROSS NRN
ARIZONA THROUGH THE DAY. HEAVIER RAIN...HAIL...AND STRONG WINDS ARE
LIKELY WITH THESE STORMS. STRONG SHEAR (STORM RELATIVE HELICITY IS
375 ON THIS MORNING SOUNDING) WILL LEAD TO THE POSSIBILITY OF A FEW
SUPPER CELL THUNDERSTORMS. THE FLASH FLOOD WATCH CONTINUES FOR TODAY
WITH THE POTENTIAL FOR VERY HEAVY RAIN.

AFTER THE COLD FRONT PASSES...MUCH DRIER AND MORE STABLE AIR WILL
MOVE INTO THE AREA. THIS DRYING WILL TAKE PLACE BY THIS EVENING IN
YAVAPAI COUNTY...BUT WILL LIKELY REACH APACHE COUNTY LATE
NIGHT/EARLY MORNING. THIS WILL SIGNIFICANTLY DROP THE CHANCES OF
PRECIPITATION.

&&
.AVIATION...FOR THE 18Z PACKAGE...SCT -SHRA/-TSRA THIS MORNING BCMG
SCT-NMRS SHRA/TSRA THIS AFTERNOON. SOME TSRA BCMG SVR WITH LARGE
HAIL PSBL. DRIER MORE STABLE AIR MOVING SLOWLY INTO WRN YAVAPAI
COUNTY AFTER SUNSET TONIGHT WITH AREAS OF BR/FG BY SUNRISE SATURDAY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.
&&

.FGZ WATCHES/WARNINGS/ADVISORIES...FFA ALL FGZ ZONES UNTIL 6 PM MST
TODAY.

&&

MAS/DL

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
655 AM MST FRI OCT 6 2006

AZZ004>018-037>040-070700-
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-
655 AM MST FRI OCT 6 2006

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

.DAY ONE...TODAY

A FLASH FLOOD WATCH IS IN EFFECT FOR NORTHERN AND CENTRAL ARIZONA
THROUGH 6 PM MST TODAY.

A STRONG AND VERY MOIST PACIFIC STORM SYSTEM WILL CONTINUE TO
AFFECT THE AREA TODAY...WITH STRONG THUNDERSTORMS INCREASING IN
COVERAGE TODAY. STORM TOTAL RAINFALL AMOUNTS WILL GENERALLY BE
1 TO 3 INCHES WITH LOCALLY HEAVIER AMOUNTS OF 3 TO 4 INCHES
POSSIBLE IN FAVORED LOCATIONS. AREA CREEKS AND RIVERS...AS
WELL AS DRY WASHES AND POORLY DRAINED AREAS...WILL SEE A
SIGNIFICANT INCREASE IN WATER FLOW TODAY. IN ADDITION...SOME
STORMS WILL BECOME SEVERE TODAY...WITH LARGE HAIL IN EXCESS OF
3/4 INCH DIAMETER AND SEVERE WIND GUSTS IN EXCESS OF 60 MPH
POSSIBLE. SEVERE THUNDERSTORMS CAN OCCASIONALLY PRODUCE TORNADOS.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

LOW PRESSURE WILL REDEVELOP OVER SOUTHERN CALIFORNIA BRINGING
UNSETTLED WEATHER TO NORTHERN ARIZONA. ADDITIONAL SHOWERS AND
THUNDERSTORMS ARE POSSIBLE...ESPECIALLY NEAR THE NEW MEXICO
BORDER SUNDAY THROUGH EARLY NEXT WEEK.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SEVERE WEATHER
CONDITIONS...INCLUDING HAIL OVER PENNY SIZE OR 3/4 INCH
DIAMETER...WIND GUSTS OVER 58 MPH...OR TORNADIC ACTIVITY.