Hail in Arizona, August 19, 2003

NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
915 AM MST TUE AUG 19 2003

.SYNOPSIS...HIGH PRESSURE ALOFT WILL MOVE TO NEAR THE FOUR CORNERS
TODAY. THIS WILL RESULT IN A MORE SOUTHEASTERLY FLOW AND AN INCREASE
IN MOISTURE LASTING INTO THE WEEKEND. EXPECT SCATTERED SHOWERS AND
THUNDERSTORMS...MAINLY DURING THE AFTERNOON AND EARLY EVENING HOURS.

.DISCUSSION...RADAR AND SATELLITE INDICATE REMNANT CONVECTION OVER
FAR SOUTHERN YAVAPAI COUNTY FROM OVERNIGHT CONVECTIVE COMPLEX OVER
SOUTHERN AZ...ALONG WITH NEW CONVECTIVE DEVELOPMENT NORTH OF THAT
REGION. MORNING KFGZ SOUNDING HAS SIGNIFICANTLY COOLER BOUNDARY LAYER
ALONG WITH INCREASED MOISTURE PROFILE. GULF SURGE CONTINUES TO ADD
MOISTURE TO THE LOW LEVELS AS WELL ACROSS SOUTHERN PORTIONS OF THE
FORECAST AREA. ONCE AIRMASS HEATS UP...CAPE OF AROUND 1500 J/KG
SHOULD MAKE FOR AN ACTIVE CONVECTIVE DAY ...ESPECIALLY WHERE THERE
IS LITTLE CLOUD COVER. CURRENT CLOUD COVER OVER YAVAPAI COUNTY WILL
LEAD TO A LATE START TO CONVECTION THERE...BUT NORTH OF THIS CLOUD
SHIELD...EXPECT ADEQUATE HEATING AND DESTABILIZATION TO LEAD TO HIGH
CHANCE POPS ALONG THE RIM WITH DECREASING POPS TOWARD THE UTAH
BORDER FURTHER FROM THE DEEPER MOISTURE. PREC WATER VALUES OF AROUND
AN INCH ALONG WITH WEAK CLOUD LAYER WINDS WILL ALLOW SOME STORMS TO
PRODUCE LOCALLY HEAVY RAINS. WITH THESE CAPE VALUES...HAIL IS ALSO
POSSIBLE THIS AFTERNOON.

MODELS INDICATE A CONVECTIVELY GENERATED CIRCULATION OVER NORTHERN
MEXICO TO MOVE NORTHWESTWARD AROUND THE HIGH THAT IS FORMING OVER
NEW MEXICO. THIS WILL HELP TO GENERATE THUNDERSTORM ACTIVITY OVER
WESTERN PORTIONS OF THE FORECAST AREA THIS AFTERNOON...AND AS IT
MOVES NORTHWARD OVERNIGHT SHOULD HELP TO KEEP CONVECTION GOING OVER
WESTERN ZONES THROUGH THE NIGHT. WOULDNT BE SURPRISED TO SEE A
CONVECTIVE COMPLEX DEVELOP OVER THIS REGION OVERNIGHT. ADDITIONALLY
AS THIS SYSTEM MOVES NORTHWARD...SOUTHEAST FLOW INCREASES AHEAD OF
IT WHICH WILL INCREASE THE MID-LEVEL SHEAR LATER THIS AFTERNOON AND
ESPECIALLY THIS EVENING. ANOTHER CIRCULATION CENTER FURTHER SOUTH IN
MEXICO WILL LIKELY LEAD TO ANOTHER CONVECTIVE COMPLEX TO OUR SOUTH
AS WELL. SHOULD BE AN INTERESTING 36 HOURS. WILL UPDATE GRIDS AND
ZONE PRODUCTS TO REFLECT CURRENT THINKING. STAUDENMAIER

.CODED TEMPERATURES/POPS FOR SELECTED CITIES IN NORTHERN ARIZONA

CITY             TEMPERATURES HI/LO           PROBABILITY OF PRECIP
                 TDY TON   WED     THU        TDY TON   WED   THU
FLAGSTAFF        079/053 077/051 077/053      050 030 040 030 040 030
WINSLOW          089/063 087/062 088/063      030 030 030 030 030 020
PRESCOTT         086/062 084/061 084/063      040 030 040 030 040 030
PAGE             098/071 094/068 093/071      020 020 020 020 020 020
WINDOW ROCK      084/053 083/052 081/051      040 030 040 030 040 020
CANYON DE CHELLY 090/061 089/060 087/059      030 030 030 020 030 020
COTTONWOOD       097/070 095/069 095/071      040 030 030 030 030 020
GRAND CANYON     084/051 082/051 080/054      030 030 030 030 030 020
GREER            074/050 072/048 072/050      050 040 050 040 050 030
HEBER            084/055 082/053 082/055      050 030 040 040 040 030
JACOB LAKE       077/053 075/051 075/053      030 020 030 030 030 020
NAVAJO N.M.      084/058 083/057 081/056      030 020 030 030 030 020
PAYSON           090/063 088/062 088/064      040 030 040 030 040 020
SEDONA           094/068 092/067 092/069      040 030 030 030 040 020
SELIGMAN         089/061 087/060 087/062      040 030 030 030 030 020
SHOW LOW         084/061 082/059 082/061      050 040 040 040 040 030
ST. JOHNS        089/060 088/059 089/060      040 030 040 030 040 020
WUPATKI N.M.     091/064 089/063 090/064      030 030 030 030 030 020

AZZ004>018-037>040-200200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1000 AM MST TUE AUG 19 2003

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

.DAY ONE...TODAY

ADDITIONAL MOISTURE HAS MOVED INTO THE AREA FROM THUNDERSTORM ACTIVITY
TO THE SOUTH OVERNIGHT. AN AREA OF THUNDERSTORMS HAS ALREADY DEVELOPED
AROUND PHOENIX AND WILL MOVE NORTHWEST INTO SOUTHERN YAVAPAI COUNTY.
ADDITIONAL SHOWERS AND THUNDERSTORMS WILL DEVELOP THROUGHOUT THE
MORNING HOURS...ESPECIALLY ALONG THE MOGOLLON RIM AND LOCATIONS SOUTH
WHERE THE DEEPER MOISTURE RESIDES. A CIRCULATION CENTER OVER
SOUTHWEST ARIZONA WILL HELP TO ORGANIZE CONVECTION AND ENHANCE
THE SOUTHEASTERLY WIND FLOW OVER THE WESTERN PORTION OF THE FORECAST
AREA. THIS WILL RESULT IN STORM MOVEMENT GENERALLY TOWARD THE WEST. OVER
NORTHEASTERN PORTIONS OF THE FORECAST AREA...LIGHTER WINDS WILL RESULT IN
LITTLE STORM MOVEMENT. THE MAIN THREAT FROM THUNDERSTORMS TODAY WILL
BE HEAVY RAIN...ALONG WITH THE THREAT OF HAIL.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.
A MOIST AND UNSTABLE AIR MASS WILL REMAIN OVER ARIZONA RESULTING IN
A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY.

.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.