Flood in Arizona, July 18, 2002

NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
230 PM MST THU JUL 18 2002

.SYNOPSIS...A VERY MOIST AIR MASS WILL REMAIN OVER NORTHERN ARIZONA
INTO THE WEEKEND. THE DAILY SHOWER AND THUNDERSTORM ACTIVITY WILL
CONTINUE WITH TEMPERATURES NEAR SEASONAL LEVELS.

.DISCUSSION...UPPER TROF MOVING INTO WEST CENTRAL NV ATTM. THIS
FEATURE PROGGED TO WEAKEN WITH TIME AND EJECT TO THE NE AS RIDGE
REESTABLISHES ITSELF OVER THE DESERT SW. WEAK IMPULSE NOTED ON WV
IMAGERY MOVING NORTHEAST THRU CENTRAL AZ THIS NOON. THIS AIDING
CONVECTION OVER YAVAPAI COUNTY AND THE NORTHERN RIM ATTM. THIS
FEATURE TO CONTINUE MOVING THRU NE CWA THIS EVENING. ATMOSPHERE OVER
CWA TO REMAIN MOIST INTO THE WEEKEND. NUMERICAL GUIDANCE SHOWS
LITTLE CHANGE IN SFC DPS THRU SATURDAY SO WILL CONTINUE FCST OF
SCATTERED DAILY CONVECTION OVER ENTIRE CWA. MODELS HAVE BEEN
CONSISTENT LAST FEW RUNS IN BRINGING DRIER AIR MASS IN FROM THE WEST
OVER THE WEEKEND. STREAMLINE ANALYSIS SHOWS DEEP LAYER DRYING THRU
ALL BUT EASTERN CWA BY SUNDAY. WESTERN SECTIONS OF CWA MAY SEE
DOWNTURN IN CONVECTIVE ACTIVITY BY SUNDAY. BUT DONT BELIEVE THE
DRIER AIR WILL REACH THE EASTERN SECTIONS OF THE CWA SO WILL
CONTINUE TO HAVE THE HIGHEST POPS IN THAT REGION. BY MONDAY FLOW
ALOFT BECOMES MORE EASTERLY AND MOISTURE EXPECTED TO SURGE BACK INTO
THE STATE.

EXTENDED...HIGH PRESSURE CENTER DANCING AROUND THE 4-CORNERS REGION
NEXT WEEK. MOIST E-SE FLOW TO REENFORCE MOISTURE OVER THE STATE. SEE
NO REASON TO DEVIATE FROM CURRENT STANDARD MONSOON FCST. DF

.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        056/077 053/079 050/080      030 040 030 040 030 030
WINSLOW          064/089 063/090 060/091      020 030 020 030 020 020
PRESCOTT         064/089 062/090 059/091      030 030 020 030 020 020
PAGE             072/093 072/095 069/096      020 020 020 020 020 020
WINDOW ROCK      053/083 053/082 050/083      030 050 030 040 030 040
CANYON DE CHELLY 059/089 059/088 056/089      020 040 020 030 020 030
COTTONWOOD       072/100 070/101 067/102      020 020 020 020 020 020
GRAND CANYON     055/079 052/081 049/082      020 030 020 030 020 020
GREER            052/073 049/075 046/076      050 070 050 060 050 050
HEBER            057/082 054/084 051/085      040 060 040 060 040 040
JACOB LAKE       056/075 053/077 050/078      020 030 020 030 020 020
NAVAJO N.M.      057/083 057/082 054/083      020 040 020 030 020 030
PAYSON           065/094 063/095 060/096      030 020 020 030 020 020
SEDONA           070/098 068/099 065/100      020 020 020 020 020 020
SELIGMAN         057/092 055/093 052/094      020 020 010 020 010 010
SHOW LOW         064/083 061/085 058/086      030 040 030 040 030 030
ST. JOHNS        059/083 058/084 055/085      030 040 030 040 030 030
WUPATKI N.M.     067/091 066/092 063/093      020 030 020 030 020 020

AZZ004>018-037>040-181930-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
925 AM MST THU JUL 18 2002

...WIDESPREAD SHOWERS AND THUNDERSTORMS TODAY. STORMS WILL BE SLOW
MOVING...INCREASING THE RISK OF URBAN AND SMALL STREAM FLOODING.
MOST FAVORED LOCATIONS FOR SIGNIFICANT CONVECTION WILL BE THE
WESTERN MOGOLLON RIM...THE LITTLE COLORADO RIVER VALLEY...AND THE
WHITE MOUNTAINS...

DISCUSSION...DEEP MOISTURE PERSISTS OVER NORTHERN ARIZONA AND WILL
FUEL WIDESPREAD THUNDERSTORMS TODAY. THE MOST SIGNIFICANT STORMS ARE
EXPECTED OVER THE WHITE MOUNTAINS AND THE LITTLE COLORADO RIVER
VALLEY. WIND FLOW ALOFT IS LIGHT AND THE STORMS WILL BE SLOW MOVING
WITH MOVEMENT GENERALLY TO THE NORTHWEST. PRECIPITATION RATES WILL
BE SIMILAR TO THOSE OF RECENT DAYS...BUT RAINFALL ACCUMULATION OVER
A PARTICULAR LOCATION DUE TO THE SLOW STORM MOVEMENT WILL INCREASE
THE RISK OF URBAN AND SMALL STREAM FLOODING.

BURNED AREA RAIN OUTLOOK...
SMALL AMOUNTS OF RAIN CAN CAUSE FLASH FLOODING IN BURNED OUT AREAS.

SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED IN AND AROUND THE
RODEO-CHEDISKI AND INDIAN BURN AREAS TODAY. THE STORMS WILL BE SLOW
MOVING IN NATURE WHICH WILL INCREASE THE RISK OF FLOODING. THE
CHEDISKI-RODEO BURN AREA WILL EXPERIENCE THE GREATEST RISK DUE TO
THE LIKELIHOOD OF STRONGER STORMS DEVELOPING OVER THAT AREA.

DF