Severe Thunderstorm Warning 71, NWS Flagstaff, AZ

000 
WWUS55 KFGZ 312051
SVSFGZ

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
150 PM MST FRI AUG 31 2007

AZC007-312100-
/O.CON.KFGZ.SV.W.0071.000000T0000Z-070831T2100Z/
GILA AZ-
150 PM MST FRI AUG 31 2007

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 200 PM MST
FOR NORTHWESTERN GILA COUNTY...

AT 145 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 2 MILES NORTHEAST OF STAR VALLEY...OR ABOUT 8 MILES NORTHEAST 
OF PAYSON...MOVING SOUTHWEST AT 5 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  STAR VALLEY BY 155 PM MST...

LAT...LON 3432 11115 3434 11126 3420 11129 3418 11107

$$
JJ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
915 AM MST FRI AUG 31 2007

.SYNOPSIS...EXPECT SCATTERED AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS TO CONTINUE EACH DAY WELL INTO NEXT WEEK. THE BEST
CHANCE FOR STORMS WILL BE ALONG AND SOUTH OF THE MOGOLLON RIM AND
WHITE MOUNTAINS. TEMPERATURES WILL REMAIN SLIGHTLY ABOVE NORMAL
READINGS FOR THIS TIME OF YEAR.

&&

.DISCUSSION...
AT 9 AM...DEBRIS CLOUDS ARE THINNING ACROSS EASTERN COCONINO AND
NORTHERN NAVAJO COUNTIES. THIS CLOUD COVER HAS 9 AM TEMPS SOME 2 TO
5 DEGREES COOLER THAN 24 HOURS AGO AND SHOULD LEAD TO A LATER START
AND LESS COVERAGE OF TSTORMS IN THESE AREAS THIS AFTERNOON.
THE 12Z BELLEMONT SOUNDING SHOWS HIGHER CAPE AND BETTER INSTABILITY
ALONG WITH LIGHT WEST TO EAST STORM MOTION. OUR POP GRIDS FOR THIS
AFTERNOON ALREADY SHOW GREATEST CHANCES FOR AREAS WEST OF A LINE
FROM JACOB LAKE TO ST JOHNS AND THIS LOOKS GOOD GIVEN THE CURRENT
CLOUD COVER.

DL

PREV DISCUSSION...220 AM MST...NUMEROUS OUTFLOWS MEANDERING AROUND
THE STATE TONIGHT COUPLED WITH WITH WEAK FORCING FROM A S/WV OVER
NORTHWEST ARIZONA HAS PROVIDED QUITE A BIT OF DEBRIS CLOUD. SOME
WEAK CONVECTION CONTINUES EAST OF FLAGSTAFF...WITH AREAS OF VERY
LIGHT STRATIFORM RAIN FALLING OVER THE WESTERN MOGOLLON RIM.

A MID-LEVEL HIGH LOCATED WEST OF THE CWA WILL STAY IN PLACE THROUGH
TUESDAY OF NEXT WEEK...WITH NO MAJOR CHANGES EXPECTED IN THE
SYNOPTIC PATTERN. WEAK FLOW WITH EASTERLIES ALOFT WILL FAVOR
CONVECTION FORMING OVER THE HIGHER TERRAIN...AND THEN DRIFTING WEST
TO SOUTHWEST THROUGH THE AFTERNOON OF EACH DAY. A S/WV (MENTIONED
ABOVE) WILL MOVE THROUGH SOUTHERN UTAH TODAY AND EARLY SATURDAY.
THIS WAVE MAY PROVIDE A BIT MORE ACTIVITY TO THE NORTHERN ZONES IN
THE NEXT 24 HOURS. OTHERWISE...THE NORTHERN ZONES ARE CLOSEST TO
SOMEWHAT DRIER AND SLIGHTLY MORE STABLE AIR...SO THESE ZONES WILL BE
THE LEAST ACTIVE OVERALL IN THE NEXT SEVERAL DAYS.

MOISTURE BOTH ALOFT...AND IN THE BOUNDARY LAYER...HAS BECOME DEEPER
IN THE LAST 24 HOURS DUE TO CONVECTIVE RECYCLING...AND CONTINUOUS
PRESSURE FROM THE LARGE POOL OF HIGH PW AIR TO OUR WEST. WE HAVE
BUMPED POPS UP SLIGHTLY YET AGAIN FOR THE NEXT SEVERAL DAYS TO
ACCOUNT FOR THE AIRMASS CONTINUING TO BECOME MORE MOISTURE RICH DUE
TO THE PROCESSES MENTIONED ABOVE.

BY TUESDAY OR WEDNESDAY OF NEXT WEEK...MODELS STILL DEVELOP A TROUGH
OF LOW PRESSURE IN THE GREAT BASIN WHICH MAY AFFECT NORTHERN AND
CENTRAL ARIZONA THROUGH AT LEAST THURSDAY. THIS TROUGH MAY BE THE
TYPICAL SEASON ENDER FOR OUR REGION...WHICH FREQUENTLY MEANS LOTS
OF HEAVY RAIN AND ORGANIZED CONVECTION...WE WILL HAVE TO WAIT AND
SEE. PREVIOUS RUNS ALSO PHASED IN A TROPICAL SYSTEM OVER SOUTHERN
ARIZONA WITH THIS TROUGH...THIS NO LONGER SEEMS TO BE THE CASE
ALTHOUGH IT CANNOT BE RULED OUT JUST YET. FOR NOW...WE WILL CONTINUE
TO SHOW A HIGHER CHANCE OF PRECIPITATION LATE IN THE SEVEN DAY
PERIOD...ALONG WITH DECREASED TEMPERATURES. PETERSON.

&&

AVIATION...FOR THE 18Z PACKAGE...DEEP LAYER HIGH PRESSURE AND A
MOIST AIR MASS WILL REMAIN OVER ARIZONA. AS A RESULT...EXPECT
SCATTERED THUNDERSTORMS AFTER 18Z TENDING TO DEVELOP FIRST OVER THE
HIGHER TERRAIN. IN ADDITION...INCREASED MOISTURE HAS MOVED ACROSS
EXTREME NORTHEAST ARIZONA WITH AN UP-TICK IN THUNDERSTORM COVERAGE
ANTICIPATED NORTH OF THE MOGOLLON RIM. IN THE VICINITY OF STRONGER
STORMS EXPECT CEILINGS OF 3-6 KFT AGL AND WIND GUSTS TO 30 KTS.
SHOWERS AND THUNDERSTORMS WILL GRADUALLY DIMINISH AFTER 02Z.
AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

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

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
934 AM MST FRI AUG 31 2007

AZZ004>018-037>040-010700-
BLACK MESA AREA-CHINLE VALLEY-CHUSKA MOUNTAINS AND DEFIANCE PLATEAU-
COCONINO PLATEAU-EASTERN MOGOLLON RIM-GRAND CANYON COUNTRY-
KAIBAB PLATEAU-LITTLE COLORADO RVR VLY IN APACHE CO-
LITTLE COLORADO RVR VLY IN COCONINO CO-
LITTLE COLORADO RVR VLY IN NAVAJO CO-MARBLE AND GLEN CANYONS-
NORTHEAST PLATEAU AND MESAS SOUTH OF 264-
NORTHEAST PLATEAUS AND MESAS 264 NORTH-NORTHERN GILA COUNTY-
OAK CREEK AND SYCAMORE CANYONS-WESTERN MOGOLLON RIM-WHITE MOUNTAINS-
YAVAPAI COUNTY MOUNTAINS-YAVAPAI COUNTY VALLEYS AND BASINS-
934 AM MST FRI AUG 31 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR...

.DAY ONE...TODAY

SCATTERED THUNDERSTORM ACTIVITY IS EXPECTED TODAY WEST OF
A LINE FROM JACOB LAKE TO ST JOHNS. ISOLATED THUNDERSTORMS ARE
EXPECTED EAST OF THIS LINE.

.DAYS TWO THROUGH SEVEN... SATURDAY THROUGH FRIDAY.

THE CURRENT FORECAST IS FOR SCATTERED AFTERNOON AND EVENING SHOWER
AND THUNDERSTORM ACTIVITY TO CONTINUE THROUGH NEXT FRIDAY.

.SPOTTER INFORMATION STATEMENT...

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

41