Severe Thunderstorm Warning 76, NWS Flagstaff, AZ

000 
WWUS55 KFGZ 052054
SVSFGZ

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
152 PM MST WED SEP 5 2007

AZC007-052102-
/O.EXP.KFGZ.SV.W.0076.000000T0000Z-070905T2100Z/
GILA AZ-
152 PM MST WED SEP 5 2007

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN GILA COUNTY
EXPIRES AT 200 PM MST...

THE STORM THAT HAD PROMPTED THE SEVERE THUNDERSTORM WARNING HAS 
WEAKENED. HEAVY RAIN AND HAIL UP TO A HALF INCH IN DIAMETER ARE 
STILL POSSIBLE ALONG PORTIONS OF HOUSTON MESA ROAD SOUTH OF 
WHISPERING PINES THROUGH 210 PM MST.

LAT...LON 3434 11138 3423 11133 3430 11121 3440 11127

$$

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
950 AM MST WED SEP 05 2007

.SYNOPSIS...AS DEEP MONSOONAL MOISTURE AND THE SOUTHERN EDGE OF A
PACIFIC STORM SYSTEM MOVE INTO NORTHERN ARIZONA TODAY...THERE WILL
BE THUNDERSTORMS WHICH WILL SPREAD ACROSS NORTHERN ARIZONA TODAY AND
TONIGHT. A FEW STORMS WILL BE CAPABLE OF PRODUCING LARGE HAIL...
STRONG WIND GUSTS AND VERY HEAVY RAINFALL. FOR THURSDAY INTO
THE WEEKEND...MOISTURE WILL LINGER FROM THE MOGOLLON RIM SOUTHWARD
WITH A CHANCE OF SHOWERS AND THUNDERSTORMS CONTINUING. THERE WILL BE
SOME DRYING NORTH OF THE MOGOLLON RIM.

&&

.DISCUSSION...AN UPPER LEVEL LOW OVER NORTH CENTRAL NEVADA/SW IDAHO
WILL INFLUENCE OUR WEATHER HERE IN NORTHERN ARIZONA TODAY. A TROUGH
EXTENDS SOUTHWARD FROM SALT LAKE CITY SOUTHWEST TO AROUND LAS VEGAS.
ALONG AND A HEAD OF THIS TROUGH SUBTROPICAL MOISTURE IS MOVING
NORTHWARD THROUGH THE SOUTHERN COLORADO RIVER BASIN AND EASTERN
CALIFORNIA. AT THE SAME TIME DRIER AIR IS MOVING IN ALOFT AS SHOWN
IN WV AND IPW AT KINGMAN AZ. THE EFFECT OF A MOISTENING BOUNDARY
LAYER AND DRYING ALOFT WILL ONLY ENHANCE THE MICROBURST POTENTIAL
FROM STRONG THUNDERSTORMS AND HELP IN THE WET BULBING EFFECTS TO
PRODUCE LARGER HAIL. THE MAIN THREAT AREA BASED ON CURRENT MODEL
SOUNDING EXTENDS ALONG AND NORTHWEST OF A LINE FROM KPRC TO KFLG TO
APPROX. 35NM W OF K0V7 (KAYENTA)...COVERAGE OF THE SEVERE THREAT
WILL BE ISOLATED TO THE STRONGEST STORMS. ALONG AND NORTH OF THE
SAME LINE...COOLING IN THE UPPER LEVELS AND A MOISTENING BOUNDARY
LAYER WILL HELP TO PRODUCE ABOVE AVERAGE CAPE VALUES OVER WHAT WE
NORMALLY SEE IN THE DAY TO DAY MONSOON REGIME WITH CAPE VALUES
RANGING FROM 1200 TO 1800 J/KG WHICH IS SIGNIFICANT FOR THIS AREA.
ANOTHER AID WILL BE WEAK SYNOPTIC LIFT OVER THIS NORTHWEST CORNER OF
THE STATE WITH GOOD SHEAR FROM MID TO UPPER LEVELS WITH A GOOD
PORTION OF THE CAPE BEING IN THIS SHEAR LAYER...SO EXPECTING
ORGANIZED STRONG THUNDERSTORMS WITH MULTIPLE LINEAR BANDS POSSIBLE
ACROSS NORTHWEST SECTIONS OF THE STATE LATER THIS MORNING AND
AFTERNOON. THE CHALLENGE WILL BE DETECTING THE MICRO-BURST POTENTIAL
WITH RADAR BEAMS 12K TO 18K  FEET MSL IN THIS AREA OF CONCERN.
ELSEWHERE ACROSS THE CWA EXPECTING STRONG PULSE STORMS. THERE WILL
ALSO BE AN ISOLATED THREAT OF HEAVY RAIN AND POSSIBLE LOCALIZED
FLOODING.

ZONES AND GRIDS WILL BE UPDATED FOR THE TODAY PERIOD TO REFLECT THE
CONVECTIVE THREAT OVER THE NORTHWEST AND THE HEAVY RAIN THREAT.

&&

.AVIATION...FOR THE 18Z PACKAGE...ISOLD-SCT SHRA/TSRA WILL DEVELOP
OVER THE HGHR TRRN MVG NEWD INTO LOWER ELEVATIONS AFT 20Z. SOME
+TSRA WITH SFC WIND GUSTS TO 35 KTS AND HAIL PSBL MAINLY NORTH AND
WEST OF A KPRC-KFLG-K0V7 LINE BTWN 20Z WED - 02Z THURSDAY.
CONVECTION DIMINISHING BTWN 03-06Z THURSDAY. AVIATION DISCUSSION NOT
UPDATED FOR AMENDMENTS.

&&

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

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
910 AM MST WED SEP 5 2007

AZZ004>018-037>040-060700-
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-
910 AM MST WED SEP 5 2007

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

.DAY ONE...TODAY

AN UPPER LEVEL TROUGH OF LOW PRESSURE WILL MOVE ACROSS PORTIONS OF
NORTHERN ARIZONA TODAY. SUBTROPICAL MOISTURE IS BEING PULLED
NORTHWARD A HEAD OF THE LOW PRESSURE TROUGH. THIS MOISTURE WILL
INTERACT WITH THE TROUGH INCREASING THE THREAT OF SEVERE WEATHER
TODAY ALONG AND NORTHWEST OF A LINE FROM PRESCOTT TO FLAGSTAFF TO
NAVAJO NATIONAL MONUMENT. THE MAIN THREAT WILL BE ISOLATED STRONG
STORMS PRODUCING LARGE HAIL AND DAMAGING WINDS. ELSEWHERE ACROSS
NORTHERN ARIZONA STRONG THUNDERSTORM COULD PRODUCE AN ISOLATED HEAVY
RAIN THREAT AND POSSIBLE LOCALIZED FLOODING.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

FOR THURSDAY...CURRENT THINKING IS THAT THE REMAINS OF HENRIETTE
WILL MOVE ACROSS THE EASTERN MOGOLLON RIM AND WHITE MOUNTAINS WITH
HEAVY RAIN POSSIBLE. ELSEWHERE ON THURSDAY...DRIER AIR FROM THE
NORTHWEST ALONG WITH SINKING MOTION ALOFT WILL INHIBIT RAINFALL
POTENTIAL.

STAY TUNED FOR UPDATES CONCERNING THIS DEVELOPING WEATHER SITUATION.

FOR FRIDAY AND THE WEEKEND...AS HENRIETTE MOVES TO THE EAST...THE
THREAT FOR AFTERNOON AND EVENING THUNDERSTORMS WILL CONTINUE AS
SUBTROPICAL MOISTURE WILL LINGER OVER PORTIONS OF NORTHERN ARIZONA.

.SPOTTER INFORMATION STATEMENT...

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