Severe Thunderstorm Warning 13, NWS Flagstaff, AZ

NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
230 PM MST MON JUL 21 2003

.SYNOPSIS...SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGHOUT THIS WEEK AS A MOIST AIRMASS REMAINS IN PLACE OVER
NORTHERN ARIZONA. HIGH PRESSURE TO THE NORTH WILL KEEP SEASONABLY
WARM AFTERNOON CONDITIONS OVER MUCH OF THE STATE FOR THE NEXT
SEVERAL DAYS.

.DISCUSSION...AS EXPECTED...SCATTERED THUNDERSTORMS DEVELOPED OVER
THE WESTERN RIM AND NORTHERN MOUNTAINS AND EVENTUALLY OVER THE
EASTERN RIM/WHITES EARLY THIS AFTERNOON. CONVECTION GENERATING
STRONG OUTFLOWS AND COMBINED WITH NORTHEAST FLOW ALOFT...CELLS ARE
PROPAGATING OFF THE HIGHER TERRAIN AND INTO THE LOWER VALLEYS.
OUTFLOW PROPAGATING NORTHEASTWARD OFF THE RIM GENERATING MORE
CONVECTION WHICH IS THEN PUSHING SOUTHWESTWARD SO EXPECT ADDITIONAL
THUNDERSTORM DEVELOPMENT ON THE RIM EARLY THIS EVENING.
OTHERWISE...MAIN ACTIVITY SHOULD BE IN YAVAPAI/NORTHERN GILA COUNTY
THIS EVENING. WEAK INERTIAL STABILITY OVER YAVAPAI COUNTY THIS
EVENING SHOULD ALLOW CONVECTION TO LINGER THERE LONGEST...AND
GRIDS/ZONES REFLECT THIS.

WEAK WAVE IN NM TO SWING THROUGH THE SOUTHERN PART OF THE STATE
TOMORROW AS THE HIGH PRESSURE CELL BEGINS TO REFORM OVER NM. THIS
SETS UP EASTERLY FLOW OVER THE FORECAST AREA TOMORROW. HAVE KEPT
POPS HIGHER IN THE EVENING OVER YAVAPAI COUNTY TO REFLECT THIS
STEERING FLOW. BY WEDNESDAY...HIGH BECOMES ESTABLISHED OVER NM WITH
SOUTHEAST FLOW DEVELOPING OVER THE FORECAST AREA. HAVE GONE WITH
MODERATE-GRADE POPS THROUGH THE EXTENDED AS HIGH REMAINS TO OUR EAST
AND NO STRONG DRYING TREND APPEARS IN SIGHT. NORTHWEST CORNER MAY
SEE SOME SLIGHT DRYING AS SOUTHWEST FLOW MOVES INTO THE AREA BY
THURSDAY...BUT WITH MODEL UNCERTAINTY TO THE EXACT LOCATION OF THE
HIGH THAT FAR OUT...HAVE NOT INCLUDED THIS IN THE FORECAST.
STAUDENMAIER

.FGZ...NONE.

.CODED TEMPERATURES/POPS FOR SELECTED CITIES IN NORTHERN ARIZONA

CITY             TEMPERATURES LO/HI           PROBABILITY OF PRECIP
                 TON TUE   WED     THU        TON TUE   WED     THU
FLAGSTAFF        055/084 055/083 054/082      040 040 030 040 030 040
WINSLOW          066/098 068/098 066/091      040 030 020 030 020 030
PRESCOTT         066/092 065/091 065/090      040 040 030 040 030 040
PAGE             077/102 076/101 075/094      020 020 010 020 010 020
WINDOW ROCK      054/088 054/087 054/084      040 040 020 040 030 040
CANYON DE CHELLY 067/098 066/097 066/090      040 030 020 030 020 030
COTTONWOOD       076/106 074/105 074/101      040 030 030 030 020 030
GRAND CANYON     050/088 050/087 050/084      040 030 020 030 020 030
GREER            053/080 052/079 051/078      050 060 040 060 050 060
HEBER            060/087 058/086 056/087      040 040 030 040 040 040
JACOB LAKE       055/081 054/080 054/080      040 040 020 040 030 040
NAVAJO N.M.      060/090 060/089 059/084      040 030 020 030 020 030
PAYSON           069/094 068/094 068/095      050 040 030 040 030 040
SEDONA           074/102 072/101 072/099      040 030 030 030 020 030
SELIGMAN         066/096 065/095 065/093      030 030 030 030 020 030
SHOW LOW         068/090 065/089 063/088      050 040 030 040 040 040
ST. JOHNS        066/097 066/097 065/085      040 030 030 030 030 030
WUPATKI N.M.     069/100 069/100 068/093      030 030 020 030 020 030

AZZ004>018-037>040-220200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1000 AM MST MON JUL 21 2003

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

.DAY ONE...TODAY

DEEP MOISTURE REMAINS OVER THE REGION TODAY. SCATTERED THUNDERSTORMS
ARE AGAIN EXPECTED ACROSS MOST OF THE AREA FROM LATE MORNING THROUGH
THE EVENING HOURS. THUNDERSTORM ACTIVITY IS EXPECTED TO BEGIN OVER
THE HIGHER TERRRAIN OF THE MOGOLLON RIM AND CHUSKA MOUNTAINS AFTER
10 AM AND THEN OVER THE OTHER HIGHER TERRAIN LOCATIONS OF NORTHERN
ARIZONA BY LATE MORNING AND EARLY AFTERNOON. BY THE MID-AFTERNOON
HOURS...STORMS ARE EXPECTED TO MOVE SOUTHWEST INTO PORTIONS OF
NORTHERN GILA AND YAVAPAI COUNTIES WHERE ACTIVITY WILL LINGER INTO
THE EVENING.

THE BEST THREAT FOR STRONGER STORMS TODAY WILL BE ALONG THE SOUTHERN
EDGE OF THE MOGOLLON RIM AND WHITE MOUNTAINS AS WELL AS NORTHERN GILA
COUNTY AND YAVAPAI COUNTY. THE MAIN THREAT FROM THUNDERSTORM ACTIVITY
TODAY WILL BE BRIEF HEAVY DOWNPOURS AND SMALL HAIL. A FEW STORMS MAY
ALSO CONTAIN BRIEF GUSTY WINDS.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

MOISTURE WILL REMAIN OVER ARIZONA THROUGH THE PERIOD FOR A CONTINUED
THREAT OF MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS.

.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.