Severe Thunderstorm Warning 66, NWS Flagstaff, AZ

240 
WWUS55 KFGZ 042124
SVSFGZ

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
224 PM MST TUE OCT 4 2011

AZC025-042145-
/O.CON.KFGZ.SV.W.0066.000000T0000Z-111004T2145Z/
YAVAPAI AZ-
224 PM MST TUE OCT 4 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 245 PM MST
FOR WEST CENTRAL YAVAPAI COUNTY...

AT 218 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS
LOCATED OVER EXTREME WEST CENTRAL YAVAPAI COUNTY...OR 10 MILES WEST 
OF BAGDAD AND 50 MILES WEST OF PRESCOTT...MOVING NORTH AT 35 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  RURAL WESTERN YAVAPAI COUNTY AT 240 PM MST

LAT...LON 3456 11334 3478 11335 3484 11332 3478 11307
      3443 11328 3445 11335 3456 11335
TIME...MOT...LOC 2124Z 195DEG 31KT 3464 11330

$$

RB

934 
WWUS55 KFGZ 042140
SVSFGZ

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
240 PM MST TUE OCT 4 2011

AZC025-042150-
/O.EXP.KFGZ.SV.W.0066.000000T0000Z-111004T2145Z/
YAVAPAI AZ-
240 PM MST TUE OCT 4 2011

...THE SEVERE THUNDERSTORM WARNING FOR WEST CENTRAL YAVAPAI COUNTY
WILL EXPIRE AT 245 PM MST...

THE SEVERE THUNDERSTORM WHICH PROMPTED THE WARNING HAS WEAKENED.
THEREFORE THE SEVERE THUNDERSTORM WARNING HAS BEEN ALLOWED TO EXPIRE.

LAT...LON 3456 11334 3478 11335 3484 11332 3478 11307
      3443 11328 3445 11335 3456 11335
TIME...MOT...LOC 2140Z 195DEG 31KT 3477 11326

$$

RB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
900 AM MST TUE OCT 4 2011

.SYNOPSIS...A COLD FRONT WILL MOVE ACROSS ARIZONA TODAY. ACCOMPANYING
THE FRONT WILL BE SHOWERS AND THUNDERSTORMS...SOME POTENTIALLY
SEVERE...ALONG WITH STRONG SOUTHERLY WINDS. DRIER WEATHER IS EXPECTED
ON WEDNESDAY. A STRONGER COLD FRONT WILL SWEEP ACROSS THE STATE ON
THURSDAY WITH WIDESPREAD PRECIPITATION...INCLUDING HIGH ELEVATION
SNOW...AND MUCH COLDER TEMPERATURES.

&&

.DISCUSSION...WV IMAGERY SHOWS THE UPPER LEVEL TROUGH IS MOVING
ONSHORE ACROSS SRN CALIF THIS MORNING. AHEAD OF THE TROUGH CONVECTION
HAS BEEN ONGOING FOR MANY HOURS ACROSS SERN NV AND SRN CALIF. LIGHT
SHOWERS WERE ALSO NOTED ACROSS EASTERN AZ...INCLUDING NAVAJO AND
APACHE COUNTIES...AND FARTHER EAST IN NM. MUCH OF CENTRAL AND WESTERN
AZ IS CONVECTION FREE AT THIS TIME. SATELLITE IMAGERY ALSO INDICATES
THE TROUGH HAS TAKEN ON A NEGATIVE TILT. NAM AND SREF MODELS HAVE
HANDLED ALL OF THIS QUITE WELL.

TROUGH WILL MOVE ONSHORE DURING THE DAY AND CONVECTION IS EXPECTED TO
FILL IN ACROSS MUCH OF NRN AZ. BEST DEEP-LAYER VERTICAL SHEAR IS
CURRENTLY OVER FAR WRN AZ AND WILL PROGRESS EASTWARD DURING THE DAY.
ENOUGH SHEAR IS PRESENT FOR ORGANIZED CONVECTION TO DEVELOP AND SOME
STORMS COULD BECOME SEVERE. MAIN THREAT WILL LIKELY BE LARGE HAIL AND
STRONG WINDS...BUT CANNOT RULE OUT THE POSSIBILITY OF A TORNADO.

THE TROUGH WILL DEAMPLIFY AS IT TRAVERSES THE STATE TONIGHT IN
RESPONSE TO A STRONGER TROUGH DEVELOPING ACROSS THE ERN PACIFIC AND
WEST COAST. CONSEQUENTLY...EXPECT SHOWER ACTIVITY TO DIMINISH
OVERNIGHT AND WEDNESDAY AS THE SECOND TROUGH APPROACHES.  MODEL
SOUNDINGS CONTINUE TO SHOW MID/HIGH CLOUDS ON WEDNESDAY AND THESE
COULD PRODUCE A LIGHT SHOWER OR VIRGA SO LOW POPS REMAIN IN THE
FORECAST. SOUTHWEST WINDS WILL BECOME STRONG AND GUSTY AND WILL
LIKELY CONTINUE OVERNIGHT ESPECIALLY IN THE LOCATIONS DOWNWIND OF THE
HIGHER TERRAIN...INCLUDING EAST OF THE SAN FRANCISCO PEAKS AND KAIBAB
PLATEAU.

.PREV DISCUSSION (330 AM)...THURSDAY AND FRIDAY...A POWERFUL COLD
FRONT AND UPPER LEVEL TROUGH WILL AFFECT AZ. ON THURSDAY...A STRONG
COLD FRONT WILL CROSS OUR AREA DURING THE DAY. THERE ARE SEVERAL
IMPACTS FROM THIS FRONT...INCLUDING SOUTHWEST WIND GUSTS IN THE 40 TO
50 MPH RANGE. A BAND OF RAIN AND POSSIBLY A FEW THUNDERSTORMS ARE
EXPECTED ALONG THE FRONT...STARTING IN NW AZ AFTER MIDNIGHT THURSDAY
MORNING...REACHING THE WHITE MTNS BY EARLY AFTERNOON. THE VERY COLD
AIRMASS BEHIND THE FRONT SUGGESTS SNOW SHOWERS THURSDAY EVENING ABOVE
6500 FEET ELEVATION WEST OF A LINE FROM PAYSON TO WINDOW ROCK ...WITH
FREEZING TEMPS FRIDAY MORNING IN THIS AREA. UNSETTLED WEATHER WITH
SHOWERS ARE EXPECTED FRIDAY AS THE UPPER TROUGH LINGERS OVER THE FOUR
CORNERS. HIGH TEMPS BOTH DAYS WILL BE AROUND 20 DEGREES BELOW NORMAL
FOR EARLY OCTOBER.

SATURDAY THROUGH MONDAY...DRY NORTHWEST TO NORTHERLY FLOW ALOFT IS
EXPECTED FOR THE WEEKEND WITH FAIR WEATHER ACROSS THE AREA.

&&

.AVIATION...FOR THE 18Z PACKAGE...SHOWER AND THUNDERSTORM COVERAGE
WILL INCREASE THROUGH THE DAY AS A LOW PRESSURE SYSTEM MOVES ACROSS
ARIZONA. SOUTHERLY SURFACE WINDS OF 15-20 KT GUSTING 30-35 KT WILL
SPREAD ACROSS NORTHERN ARIZONA. STRONGER STORMS WILL PRODUCE MVFR TO
LOCAL IFR CONDITIONS...AND WILL ALSO BE CAPABLE OF WIND GUSTS IN
EXCESS OF 45 KT AND LARGE HAIL. SHOWER AND THUNDERSTORM COVERAGE
WILL DECREASE AFTER 06Z AS THE LOW HEADS EASTWARD. AVIATION
DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

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

&&

PUBLIC....................DB/DL
AVIATION..................MAS

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

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
455 AM MST TUE OCT 4 2011

AZZ004>018-037>040-050700-
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-
455 AM MST TUE OCT 4 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

A FAST MOVING UPPER LEVEL DISTURBANCE WILL CROSS NORTHERN
ARIZONA. SOUTH TO SOUTHWEST SURFACE WIND GUSTS TO NEAR 40 MPH ARE
FORECAST. SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE...AND
A FEW SEVERE THUNDERSTORMS ARE POSSIBLE FOR AREAS WEST OF A LINE
FROM PAGE TO PAYSON THIS AFTERNOON AND EVENING.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

ON WEDNESDAY...MAINLY DRY WEATHER IS EXPECTED...ALONG WITH
SOUTHWEST WIND GUSTS TO NEAR 40 MPH DURING THE AFTERNOON. GUSTY
WINDS MAY PERSIST WEDNESDAY NIGHT IN THE DONEY PARK AND HOUSEROCK
VALLEY AREAS.

THURSDAY...A STRONG COLD FRONT WILL SWEEP ACROSS ARIZONA.
SOUTHWEST WIND GUSTS FROM 40 TO 50 MPH ARE EXPECTED WITH THE
FRONT. PRECIPITATION SHOULD START OVER THE KAIBAB PLATEAU EARLY
THURSDAY MORNING AND SPREAD SOUTHEASTWARD THROUGH THE DAY. SNOW
SHOWERS MAY DEVELOP OVER AREAS ABOVE 6500 FEET THURSDAY NIGHT.
FREEZING TEMPERATURES PROBABLE FOR MUCH OF THE HIGH COUNTRY FRIDAY
AND SATURDAY MORNINGS.

.SPOTTER INFORMATION STATEMENT...

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

41

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
928 AM MST TUE OCT 04 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0415 PM     FLASH FLOOD      6 NNE GRAND CANYON VILL 36.13N 112.11W
09/11/2011                   COCONINO           AZ   PARK SERVICE

            FLASH FLOOD 6 FT DEEP FLOWED OUT OF PHANTOM CANYON INTO
            BRIGHT ANGEL CR. CREEK REARRANGED...BOULDERS
            MOVED...TREES PULLED OUT FROM PHANTOM CR DEPOSITED AT
            INTERSECTION WITH BRIGHT ANGEL CR. HIGHEST FLOOD SINCE
            1997.

&&

EVENT NUMBER FGZ1100267

DGV