Special Weather Statement, NWS Flagstaff, AZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
859 PM MST SUN SEP 11 2011

.SYNOPSIS...A LOW PRESSURE SYSTEM OVER THE SOUTHWESTERN STATES WILL
BRING A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH WEDNESDAY.
STORMS TODAY MAY PRODUCE LOCALLY HEAVY RAIN AND HAIL. COOLER THAN
NORMAL TEMPERATURES WILL CONTINUE.

&&

.DISCUSSION...THUNDERSTORMS HAVE BEEN GENERALLY DECREASING IN
COVERAGE AND INTENSITY SO FAR THIS EVENING. STILL...SHOWERS WILL
CONTINUE INTO THE NIGHT FOR MANY LOCATIONS. POP GRIDS AND FORECAST
AS A WHOLE SEEM TO BE IN RATHER GOOD SHAPE...WITH NO MAJOR UPDATES
PLANNED IN THE NEAR TERM.

&&

.PREV DISCUSSION /220 PM MST/...A CUTOFF LOW WAS LOCATED OVER
SOUTHERN CALIFORNIA THIS AFTERNOON...WITH EMBEDDED DISTURBANCES
ROTATING THROUGH THE LOW MAKING IT HARD TO PINPOINT THE LOW CENTER.
ONE DISTURBANCE AND ITS ASSOCIATED MID-LEVEL WIND SPEED MAX IS
AFFECTING MUCH OF NORTHERN ARIZONA THIS AFTERNOON AND WILL CONTINUE
TO DO SO WELL INTO THIS EVENING. SCATTERED TO NUMEROUS THUNDERSTORMS
HAVE DEVELOPED...MOST WIDESPREAD OVER YAVAPAI AND COCONINO COUNTIES.
WITH THE INCREASED VERTICAL WIND SHEAR AND SUFFICIENT CAPE...SOME OF
THE STORMS HAVE BECOME STRONG OR SEVERE...WITH LARGE HAIL...STRONG
POSSIBLY DAMAGING WINDS...AND FREQUENT LIGHTNING. THERE IS ALSO A
RISK OF LOCALIZED FLASH FLOODING DUE TO THE INTENSITY OF THE
RAINFALL. RAIN CHANCES WERE INCREASED FOR THE OVERNIGHT PERIOD
TONIGHT.

MONDAY THROUGH WEDNESDAY...GENERAL MODEL AGREEMENT THAT THE CLOSED
LOW WILL MOVE SLOWLY TOWARD ARIZONA DURING THIS TIME FRAME...WITH
THE LOW CENTER REACHING NORTHERN AZ TUESDAY NIGHT INTO WEDNESDAY.
MOISTURE WILL LINGER OVER ARIZONA AND SHOULD BE SUFFICIENT FOR A
GOOD CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY. WITH AT LEAST
WEAK WIND SHEAR CONTINUING AND COOL TEMPERATURES AT THE MID
LEVELS...STORM CHANCES WERE RAISED WITH THE LATEST FORECAST PACKAGE.
THERE IS ALSO A CHANCE OF ADDITIONAL STRONG STORMS AT SOME
POINT...THE BEST LIKELIHOOD APPEARS TO BE TUESDAY AFTERNOON THROUGH
TUESDAY NIGHT AT THIS TIME.

THURSDAY AND BEYOND...THE UPPER LOW WILL CROSS ARIZONA AND MOVE
EASTWARD. WE WILL KEEP A SLIGHT CHANCE OF DAYTIME STORMS ACROSS THE
AREA ON THURSDAY THEN DRY FRIDAY AND SATURDAY.

&&

.AVIATION...FOR THE 06Z PACKAGE...EXPECT WIDELY SCATTERED SHOWERS
WITH ISOLATED EMBEDDED THUNDERSTORMS TO CONTINUE THROUGH THE NIGHT.
STORM COVERAGE WILL INCREASE AGAIN AFTER 18Z MONDAY. AVIATION
DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

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

&&

PUBLIC..................KD/JJ
AVIATION................KD

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

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
612 AM MST SUN SEP 11 2011

AZZ004>018-037>040-120700-
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-
612 AM MST SUN SEP 11 2011

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
SCATTERED TO NUMEROUS THUNDERSTORMS ARE EXPECTED OVER NORTHERN
ARIZONA THROUGH THIS EVENING. SOME OF THE STORMS MAY BECOME
SEVERE...PRODUCING ONE INCH DIAMETER HAIL AND OR WIND GUSTS OVER
58 MPH. FLASH FLOODING WILL BE POSSIBLE WITH THE STRONGER STORMS.
AREAS WITH THE BEST CHANCE OF SEVERE WEATHER ARE YAVAPAI AND
COCONINO COUNTIES.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THUNDERSTORMS CHANCES WILL PERSIST FROM MONDAY THROUGH AT LEAST
WEDNESDAY...THOUGH THE RISK OF SEVERE WEATHER WILL DECREASE.

SPOTTER INFORMATION STATEMENT...

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

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
221 AM MST MON SEP 12 2011

AZZ015-120930-
COCONINO AZ-
221 AM MST MON SEP 12 2011

THE NATIONAL WEATHER SERVICE IN FLAGSTAFF HAS ISSUED A

SIGNIFICANT WEATHER ADVISORY FOR...
  CENTRAL COCONINO COUNTY IN NORTH CENTRAL ARIZONA

UNTIL 230 AM MST

AT 215 AM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS MOVING OVER THE SCHULTZ BURN SITE...MOVING
NORTHEAST AT 15 MPH. AUTOMATED GAGES ON THE BURN SITE INDICATE THAT
UP TO ONE-HALF INCH OF RAIN HAS FALLEN IN THE PAST HALF HOUR. NO
FLOODING IS EXPECTED AT THIS TIME BUT WASHES AND STREAMS MAY HAVE
INCREASED FLOW FOR THE NEXT HOUR.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

VERY HEAVY RAINFALL MAY CAUSE TEMPORARY PONDING ON SOME ROADS AND
MINOR FLOODING OF POOR DRAINAGE AND BURNED AREAS.

&&

LAT...LON 3536 11151 3524 11157 3532 11168 3540 11160
TIME...MOT...LOC 0920Z 225DEG 2KT 3535 11157

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