Severe Thunderstorm Warning 84, NWS Flagstaff, AZ

NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
230 PM MST THU SEP 04 2003

.SYNOPSIS...DEEP MOISTURE WILL REMAIN ACROSS NORTHERN ARIZONA
FRIDAY WHICH WILL LEAD TO SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS. DRIER AIR WILL MOVE OVER THE STATE FOR THE WEEKEND
AND INTO EARLY NEXT WEEK WITH ONLY ISOLATED THUNDERSTORM ACTIVITY
OVER THE HIGHER TERRAIN. SOME BREEZY CONDITIONS MAY DEVELOP ACROSS
NORTHERN PORTIONS OF THE STATE BY MONDAY AND TUESDAY AS A STORM
SYSTEM MOVES ACROSS UTAH.

.DISCUSSION...THUNDERSTORM ACTIVITY DEVELOPING OVER THE HIGHER
TERRAIN AND GRADUALLY MOVING INTO SOME OF THE ADJACENT VALLEYS.
EXPECT THIS ACTIVITY TO LINGER INTO THE EVENING HOURS AND THEN
DECREASE. EXPECT ADDITIONAL STORMS TO DEVELOP TOMORROW AS THE
MOISTURE REMAINS IN PLACE ALONG WITH SUFFICIENT INSTABILITY. BY
SATURDAY STRONGER NORTHWEST FLOW BEGINS TO ADVECT MUCH DRIER AIR
ALOFT INTO THE REGION. THIS WILL BEING A DRYING TREND AND DECREASE
THUNDERSTORM ACTIVITY...ESPECIALLY WEST AND CENTRAL PORTIONS. BY
SUNDAY AND MONDAY...DRIER AIR SHOULD MIX TO THE SURFACE ACROSS ALL
OF NORTHERN ARIZONA LOWERING DEWPOINTS AND FURTHER REDUCING THE
THUNDERSTORM THREAT. GFS INDICATES MOISTURE FROM THE TROPICS WILL
WORK AROUND THE HIGH AND BY TUESDAY MOVE OVER NORTHERN ARIZONA.
MODELS INDICATE SOME COOLER AIR ALOFT TO MOVE OVER THE AREA FROM THE
NORTH AT THE SAME TIME...WHICH MAY INCREASE INSTABILITY JUST ENOUGH
TO BRING A SLIGHT INCREASE TO THUNDERSTORM ACTIVITY ESPECIALLY NEAR
THE NORTHEAST CORNER. ADDITIONAL DRY AIR MOVES IN BEHIND THIS SYSTEM
BY WEDNESDAY. HAVE INTRODUCED A SLIGHT CHANCE OF POPS IN THE NORTHEAST
PART OF THE FORECAST AREA ON TUESDAY AND KEPT DRY POPS IN THE FORECAST
FROM WEDNESDAY ON. WINDS ALOFT STRENGTHEN DUE TO THESE SYSTEMS
PASSING TO OUR NORTH...BUT DONT APPEAR STRONG ENOUGH TO WARRANT ANY
SPECIAL WORDING IN THE FORECAST. LOOKS LIKE WE ARE IN THE TRANSITION
OUT OF MONSOON SEASON AND INTO THE FALL SEASON. STAUDENMAIER

.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 FRI   SAT     SUN        TON FRI   SAT     SUN
FLAGSTAFF        049/076 048/078 048/079      030 050 030 030 020 020
WINSLOW          059/090 060/091 060/093      020 030 020 020 000 000
PRESCOTT         060/084 059/086 059/087      030 040 030 020 000 010
PAGE             071/092 070/093 070/095      030 030 020 020 000 000
WINDOW ROCK      051/082 049/084 049/085      030 050 040 040 020 020
CANYON DE CHELLY 059/090 056/091 056/093      020 040 030 030 010 010
COTTONWOOD       067/097 066/099 066/100      020 030 020 020 010 010
GRAND CANYON     050/079 049/081 049/082      030 040 030 020 000 010
GREER            050/072 047/073 047/074      040 050 040 040 020 020
HEBER            052/079 051/081 051/082      040 050 040 030 020 020
JACOB LAKE       049/073 048/075 048/076      030 040 030 020 010 010
NAVAJO N.M.      056/080 055/082 055/083      030 040 040 030 010 020
PAYSON           060/088 058/089 058/091      030 040 030 020 010 000
SEDONA           066/095 065/097 065/098      030 040 030 020 010 010
SELIGMAN         058/088 057/090 057/091      030 030 030 020 000 000
SHOW LOW         053/083 052/085 052/086      040 050 040 030 020 020
ST. JOHNS        061/090 060/091 060/092      030 050 030 030 010 010
WUPATKI N.M.     067/088 062/091 062/094      030 040 020 020 010 010

AZZ004>018-037>040-050200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1000 AM MST THU SEP 4 2003

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

.DAY ONE...TODAY

SCATTERED SHOWERS AND THUNDERSTORMS WILL FORM OVER THE HIGHER
TERRAIN OF NORTHERN ARIZONA BY THE LATE IN THE MORNING BUT BE MOST
NUMEROUS OVER THE MOGOLLON RIM...KAIBAB PLATEAU AND GRAND CANYON
PARK AREAS. WINDS ALOFT WILL BE WEAK AND FROM THE WEST NORTHWEST.
ANY STORMS THAT FORM TODAY WILL BE SLOW MOVERS WITH A GENERAL
MOTION TOWARD THE SOUTHEAST AT 5 MPH.

THE MAIN AREA OF FOCUS WILL BE THE AREA OF FLAGSTAFF...THE GRAND
CANYON AND PRESCOTT WHERE INCREASING MOISTURE AND BRIGHT SUNSHINE
WILL COMBINE TO PRODUCE A VERY UNSTABLE AIR MASS. EXPECT ISOLATED
STORMS TO PRODUCE 1 INCH DIAMETER HAIL AND LOCALIZED FLOODING.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.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.