Severe Thunderstorm Warning 68, NWS Flagstaff, AZ

NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
910 AM MST MON AUG 25 2003

.SYNOPSIS...HIGH PRESSURE WILL CONTINUE TO BRING ABUNDANT MOISTURE
TO THE REGION...RESULTING IN A CONTINUATION OF AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS. AN INCREASE IN TROPICAL MOISTURE IS
EXPECTED ACROSS THE REGION BY LATE TUESDAY AND WEDNESDAY. THIS WILL
BRING AN INCREASE IN SHOWER AND THUNDERSTORM ACTIVITY THROUGH AT
LEAST THURSDAY. A SLIGHT DRYING TREND IS EXPECTED BY NEXT WEEKEND.

.DISCUSSION...MOISTURE VALUES ACROSS THE REGION UP SLIGHTLY FROM
YESTERDAY...AND THE AIRMASS IS A BIT MORE STABLE. 12Z SOUNDING LOOKS
MUCH MORE MOIST ADIABATIC THAN 24 HOURS AGO...WHICH SUPPORTS THE
CURRENT TRENDS. STILL NOT VERY MUCH IN THE WAY OF A TRIGGER TODAY
AND NOT MUCH UPPER LEVEL SUPPORT EITHER. EXPECT HEAVY RAIN PRODUCING
STORMS TO DEVELOP OVER HIGHER TERRAIN...AND THEN DRIFT SLOWLY SOUTH.
FAR NORTHERN ZONES WILL PROBABLY SEE THE LEAST ACTIVITY AS TERRAIN
FEATURES AND DYNAMICS ARE MINIMIZED. THE STORMS THAT MOVE SOUTH OF
THE RIM MAY BE ENHANCED LATE TODAY AND THIS EVENING AS SOME UPPER
LEVEL DIV...ASSOCIATED WITH THE SEEMINGLY PERMANENT TROUGH SOUTH OF
THE BIG BEND...DEVELOPS OVER THE DESERTS.

MOISTURE WILL INCREASE FURTHER TUESDAY AND WEDNESDAY AS IGNACIO
INFLUENCES THE GULF OF CALIFORNIA. YUMA DEWPOINT ALREADY 77 THIS
MORNING...SO DO NOT KNOW HOW MUCH WETTER IT CAN GET. IGNACIO DOES
HAVE THE CAPACITY TO ADD MID LEVEL MOISTURE...AND INCREASE THE
DIVERGENCE AT THE UPPER LEVELS. AS IGNACIO NEARS...THE PROBABILITY
FOR LARGE COMPLEXES NEAR THE SOUTHERN BORDER WILL ALSO INCREASE. ALL
IN ALL...IGNACIO WILL IMPROVE THE MOISTURE FLUX NORTHWARD AND
IMPROVE THE DYNAMIC SITUATION FOR WIDESPREAD AND LONG-LIVED
CONVECTION. ZONES HANDLE THESE TRENDS FINE FOR NOW. PETERSON.

.FGZ...NONE.

.CODED TEMPERATURES/POPS FOR SELECTED CITIES IN NORTHERN ARIZONA

CITY             TEMPERATURES HI/LO           PROBABILITY OF PRECIP
                 TDY TON   TUE     WED        TDY TON   TUE   WED
FLAGSTAFF        078/052 076/052 072/051      040 040 050 050 050 050
WINSLOW          090/064 089/063 085/062      020 020 030 030 030 030
PRESCOTT         085/062 083/061 078/060      040 040 050 050 050 040
PAGE             094/068 094/066 089/065      020 020 020 020 020 020
WINDOW ROCK      083/051 083/051 079/050      030 030 030 030 040 040
CANYON DE CHELLY 089/059 089/059 085/058      020 020 030 030 030 030
COTTONWOOD       096/070 094/069 089/068      040 040 050 050 040 040
GRAND CANYON     081/051 079/050 074/051      030 030 040 040 040 040
GREER            073/049 071/049 067/048      050 050 050 050 060 050
HEBER            083/054 081/054 077/053      040 040 050 050 050 050
JACOB LAKE       076/052 074/052 070/051      030 030 030 030 040 040
NAVAJO N.M.      083/056 083/056 079/055      030 030 030 030 030 030
PAYSON           089/063 087/062 082/061      040 040 040 040 040 040
SEDONA           093/068 091/067 086/066      040 040 040 040 040 040
SELIGMAN         088/061 086/060 081/059      030 030 040 040 040 030
SHOW LOW         083/060 081/060 077/059      040 040 050 050 050 050
ST. JOHNS        090/060 089/061 085/062      030 030 040 040 040 040
WUPATKI N.M.     092/065 091/064 087/063      030 030 030 030 030 030

AZZ004>018-037>040-260200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
930 AM MST MON AUG 25 2003

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

.DAY ONE...TODAY

A VERY MOIST AND UNSTABLE AIRMASS REMAINS ACROSS THE REGION TODAY.
LIGHT NORTHERLY FLOW WILL FAVOR THUNDERSTORM DEVELOPMENT ACROSS THE
HIGH TERRAIN OF CENTRAL ARIZONA BY LATE THIS MORNING. STORMS WILL
DRIFT SLOWLY SOUTH OFF THE RIM AND INTO PORTIONS OF YAVAPAI AND GILA
COUNTIES LATER THIS AFTERNOON. NORTHEAST AND NORTHERN SECTIONS OF
THE STATE WILL SEE ONLY ISOLATED THUNDERSTORM COVERAGE TODAY.

DUE TO THE VERY MOIST ATMOSPHERE ACROSS THE STATE...ISOLATED
STRONGER STORMS WILL PRODUCE TORRENTIAL RAIN THIS AFTERNOON. THIS IS
MOST LIKELY OVER PORTIONS OF THE MOGOLLON RIM AND IN PORTIONS OF
YAVAPAI COUNTY. SATURATED SOIL CONDITIONS MAY LEAD TO SOME FLOODING
WITH THE STRONGEST STORMS TODAY. THESE STORMS MAY ALSO PRODUCE
MAINLY SMALL HAIL...AND GUSTY WINDS.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

MOISTURE WILL INCREASE ACROSS THE STATE TUESDAY THROUGH THURSDAY
ASSOCIATED WITH A TROPICAL DISTURBANCE OVER THE GULF OF CALIFORNIA.
WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY WILL DEVELOP WEDNESDAY
AND THURSDAY...BEFORE SLOWLY DECREASING AGAIN BY NEXT WEEKEND.
FREQUENT HEAVY RAIN MAY LEAD TO FLOODING PROBLEMS BY MID WEEK...BUT
IT IS TOO EARLY TO PINPOINT WHERE AND WHEN.

.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.