Severe Thunderstorm Warning 90, NWS Flagstaff, AZ

NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
230 PM MST SUN SEP 7 2003

.SYNOPSIS...ENOUGH MOISTURE WILL REMAIN OVER THE AREA FOR ISOLATED
THUNDERSTORMS THIS EVENING AND AGAIN ON MONDAY. A STRONG LOW
PRESSURE SYSTEM WILL MOVE INTO UTAH BY TUESDAY...DRAWING TROPICAL
MOISTURE ACROSS NORTHERN ARIZONA. AS A RESULT...WIDESPREAD SHOWERS
AND THUNDERSTORMS ARE EXPECTED TUESDAY ASSOCIATED WITH THIS SYSTEM.
MOISTURE WILL LINGER OVER NORTHERN ARIZONA FOR THE REMAINDER OF THE
WEEK WITH A CHANCE OF THUNDERSTORMS CONTINUING.

.DISCUSSION...THERE WILL BE A FEW LINGERING THUNDERSTORMS THIS
EVENING BUT EXPECT ACTIVITY TO END BY MIDNIGHT AS WARMING MID LEVEL
TEMPERATURES STABILIZE THE ATMOSPHERE.

FOR MONDAY AND TUESDAY A LONG-WAVE TROUGH WILL DEVELOP OVER THE
WESTERN UNITED STATES. THIS WILL RESULT IN LOW TO MID LEVEL WINDS
BECOMING MORE SOUTHERLY AND TAPPING A LARGE POOL OF TROPICAL
MOISTURE JUST TO THE SOUTH OF ARIZONA. IN ADDITION...THE MID LEVELS
WILL BEGIN COOLING MONDAY AFTERNOON...SO ANY CAP THAT MIGHT EXIST
EARLY ON MONDAY WILL DISAPPEAR BY LATE IN THE DAY. MONDAY NIGHT AND
TUESDAY...DEEP LARGE SCALE UPWARD MOTION...MOIST SOUTHWEST FLOW AND
OROGRAPHIC LIFT SHOULD COMBINE TO PRODUCE QUITE A BIT OF RAINFALL
ACROSS ARIZONA. AT THIS TIME IT LOOKS LIKE THE MAIN FOCUS WILL BE
ALONG THE MOGOLLON RIM...WHITE MOUNTAINS AND LOCATIONS SOUTHWARD. IT
WILL BE IMPORTANT TO REMAIN UPDATED ON THIS DEVELOPING SITUATION.

THE THROUGH MOVES EASTWARD ON WEDNESDAY BUT ENOUGH MOISTURE LINGERS
FOR THE CONTINUED THREAT OF THUNDERSTORMS.

IN THE EXTENDED...MUCH CONFLICT IN MODEL SOLUTIONS. THE GFS LEAVES
ARIZONA IN A MONSOON LIKE SETTING WITH WEAK FLOW...PLENTY OF
MOISTURE AND DIURNAL TYPE THUNDERSTORM ACTIVITY. THE EUROPEAN MODEL
BUILDS A LONG WAVE TROUGH OVER THE WESTERN UNITED STATES WITH A
NORTHEAST TO SOUTHWEST TROUGH AXIS INTERSECTING CENTRAL NEVADA AND
CALIFORNIA. THE EUROPEAN SOLUTION HINTS TOWARD ANOTHER VERY WET
PERIOD ON FRIDAY AND SATURDAY. FOR NOW HAVE SETTLED ON A BLEND OF
THE TWO AND WILL WAIT AND SEE WHAT HAPPENS.

MCCOLLUM

.NOTE...EFFECTIVE WEDNESDAY OCTOBER 1 2003...THE TEMPERATURES AND
PROBABILITIES OF PRECIPITATION TABLE (BELOW) WILL NO LONGER BE
APPENDED TO THIS PRODUCT. THE INFORMATION...ALONG WITH PREVAILING
DAYTIME WEATHER...WILL BE AVAILABLE IN THE RECENTLY ADOPTED TABULAR
STATE FORECAST (SFT). THE SFT PROVIDES THESE FORECASTS THROUGH 7
DAYS. THE WMO HEADER FOR THIS PRODUCT IS FPUS65 KPSR. THE PRODUCT
IDENTIFIER IS PHXSFTAZ. USING THE INTERNET...YOU CAN ACCESS THE SFT
DIRECTLY AT HTTP://WWW.WRH.NOAA.GOV/CGI-BIN/GPRODUCT.PL?FLGPHXSFTAZ

.FGZ...NONE.

.CODED TEMPERATURES/POPS FOR SELECTED CITIES IN NORTHERN ARIZONA

CITY             TEMPERATURES LO/HI           PROBABILITY OF PRECIP
                 TON MON   TUE     WED        TON MON   TUE     WED
FLAGSTAFF        046/072 049/067 051/070      020 030 030 060 040 040
WINSLOW          057/085 058/079 060/082      000 020 030 050 030 030
PRESCOTT         058/083 060/078 062/081      010 030 030 050 030 030
PAGE             067/088 068/084 070/087      000 010 020 050 020 020
WINDOW ROCK      048/075 050/070 052/073      020 020 030 050 030 040
CANYON DE CHELLY 055/081 057/076 059/079      010 020 020 050 030 030
COTTONWOOD       066/094 068/089 070/092      000 020 030 050 030 020
GRAND CANYON     047/073 050/068 052/071      010 020 030 050 030 030
GREER            045/069 048/064 050/067      020 030 030 060 040 040
HEBER            049/077 052/072 054/075      020 030 030 060 040 030
JACOB LAKE       046/069 049/064 051/067      010 020 020 050 030 030
NAVAJO N.M.      054/073 056/068 058/071      020 020 020 050 030 030
PAYSON           058/087 060/082 062/085      020 020 030 050 030 030
SEDONA           065/091 067/086 069/089      010 020 030 050 040 030
SELIGMAN         056/085 058/080 060/083      010 020 030 050 030 030
SHOW LOW         055/078 058/073 060/076      020 020 030 060 040 030
ST. JOHNS        053/081 054/075 056/078      020 020 030 050 030 030
WUPATKI N.M.     059/087 060/081 062/084      010 020 030 050 030 030

AZZ004>018-037>040-080200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1000 AM MST SUN SEP 7 2003

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

.DAY ONE...TODAY

THERE WILL BE ISOLATED SHOWERS AND THUNDERSTORMS ACROSS NORTHERN
ARIZONA TODAY. A FEW OF THESE WILL BECOME STRONG WITH THE POTENTIAL
FOR 1 INCH DIAMETER HAIL. THE MAIN THREAT FOR THE ISOLATED SEVERE
STORMS WILL BE FROM ABOUT THE GRAND CANYON SOUTHWARD TO THE MOGOLLON
RIM...YAVAPAI COUNTY AND NORTHERN GILA COUNTY.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THERE IS THE POTENTIAL FOR A SIGNIFICANT RAINFALL EVENT STARTING
MONDAY NIGHT AND LASTING MOST OF TUESDAY. AT THIS TIME THE PRIMARY
FOCUS APPEARS TO THE THE MOGOLLON RIM...YAVAPAI COUNTY AND NORTHERN
GILA COUNTY. DEEP TROPICAL MOISTURE WILL BE PULLED INTO THESE AREAS
BY A DEVELOPING LOW PRESSURE SYSTEM OVER UTAH. AS MUCH AS 1 INCH OF
RAINFALL COULD FALL OVER A WIDE AREA WITH LOCALLY HIGHER
AMOUNTS. PLEASE STAY TUNED TO THE LATEST WEATHER INFORMATION
CONCERNING THIS DEVELOPING SITUATION.

.SPOTTER INFORMATION STATEMENT...

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

DEFINITION OF HAZARDOUS WEATHER...A WEATHER EVENT POSING A THREAT
TO LIFE AND PROPERTY.

AZZ004>018-037>040-081200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
345 PM MST SUN SEP 07 2003

...WIDESPREAD SHOWERS AND THUNDERSTORMS ON TUESDAY SOME WITH HEAVY
RAIN...

A STRONG LOW PRESSURE SYSTEM WILL COMBINE WITH DEEP TROPICAL
MOISTURE ON TUESDAY TO PRODUCE WIDESPREAD SHOWERS AND THUNDERSTORMS.
THE DEEPEST MOISTURE AND MOST UNSTABLE AIR MASS WILL BE LOCATED
ALONG AND SOUTH OF THE MOGOLLON RIM INCLUDING MUCH OF YAVAPAI AND
GILA COUNTIES.

SHOWERS AND THUNDERSTORMS WILL BE ON THE INCREASE TUESDAY MORNING
WITH THE HEAVIEST RAINFALL EXPECTED TO HIT TUESDAY AFTERNOON AND
NIGHT. BY WEDNESDAY MORNING MANY LOCATIONS ALONG AND SOUTH OF THE
MOGOLLON RIM ARE EXPECTED TO RECEIVE UP TO 1 INCH OF RAIN WITH LOCAL
ACCUMULATIONS OF UP TO 2 INCHES. THE SOIL ACROSS THIS AREA IS
SATURATED AND MOST RAINFALL WILL BE CONVERTED INTO RUNOFF IN AREA
WASHES...CREEKS AND RIVERS. THE LOCATION...TIMING AND AMOUNT OF
RAINFALL WILL BE ADJUSTED AS THE EVENT DRAWS NEAR. PLEASE STAY TUNED
FOR FURTHER UPDATES ON THIS DEVELOPING WEATHER SYSTEM.

FOR THE LATEST WEATHER UPDATES...CHECK THE NATIONAL WEATHER SERVICE
HOME PAGE AT WWW.WRH.NOAA.GOV/FLAGSTAFF...OR TUNE TO NOAA WEATHER
RADIO...COMMERCIAL RADIO OR TELEVISION.