Flash Flood Warning 54, NWS Tucson, AZ

SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
140 PM MST SUN AUG 24 2003

.SYNOPSIS...HIGH PRESSURE OVER THE SOUTHERN ROCKIES WILL MAINTAIN A
FAVORABLE MOIST FLOW FOR SCATTERED SHOWERS AND THUNDERSTORMS FROM
TUCSON AND WEST...WITH LESS ACTIVITY OVER FAR EASTERN ARIZONA TODAY.
INCREASING MOISTURE ASSOCIATED WITH HURRICANE IGNACIO...LOCATED
SOUTHEAST OF CABO SAN LUCAS TODAY...WILL TRACK NORTH TOWARD THE
DESERT SOUTHWEST EARLY THIS WEEK. THIS INFLUX IN MOISTURE SHOULD
LEAD TO AN UPSWING IN RAINFALL COVERAGE...ESPECIALLY TUESDAY INTO
WEDNESDAY. TEMPERATURES OVER THE NEXT SEVERAL DAYS WILL BE BELOW
SEASONAL NORMALS. A DRYING TREND IS FORECAST FOR LATE IN THE WEEK OR
OVER THE WEEKEND.

.DISCUSSION...MOISTURE AXIS REMAINED OVER AZ TODAY WITH A DRIER
AIRMASS AND WARMER AIR ALOFT ACROSS EXTREME EASTERN SECTIONS OF
GRAHAM AND COCHISE COUNTIES. LATEST RADAR IMAGERY SHOWED SHOWERS AND
A FEW THUNDERSTORMS DEVELOPING ACROSS CENTRAL COCHISE INTO WESTERN
SANTA CRUZ COUNTIES. THE MAIN AREA OF CONCERN FOR STRONG TSTMS THIS
EVENING WILL BE IN WESTERN SANTA CRUZ...PIMA AND SOUTHEAST PINAL
COUNTIES. HEAVY RAINFALL WILL BE THE MAIN THREAT...BUT THE TUS 12Z
SOUNDING ALSO SUGGESTED THAT A FEW OF THE STRONGER STORMS COULD
PRODUCE DAMAGING WINDS. THE WEATHER PATTERN WILL REMAIN ACTIVE
RAINFALL WISE WITH THE BEST CHANCE OF WIDESPREAD RAINS TUESDAY INTO
WEDNESDAY. THIS THINKING WAS BASED ON PROGGED MOISTURE STREAMING
NORTHWARD IN ASSOCIATION WITH HURRICANE IGNACIO. WILL TREND POPS UP
FOR TUESDAY AND WEDNESDAY...ALTHOUGH THE REMNANTS OF IGNACIO
CIRCULATION WILL BE SLOW TO ARRIVE IN THE DESERT SOUTHWEST.
OFFICIAL TRACK FROM NHC STILL HAD IT REACHING THE NORTHERN GULF OF
CALIFORNIA AROUND FRIDAY MORNING.

.TWC...NONE.

AZZ019-029>035-251400-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1155 AM MST SUN AUG 24 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST ARIZONA

.DAY ONE...TODAY

SYNOPSIS...ANOTHER ROUND OF THUNDERSTORMS IS EXPECTED TO DEVELOP
LATE THIS AFTERNOON AND EVENING AS ABUNDANT MOISTURE IS IN PLACE.
LAST NIGHTS THUNDERSTORMS MAY SLOW THE DEVELOPMENT OF STORMS TODAY
BUT THIS EVENING THUNDERSTORMS SHOULD BE ABLE TO MOVE INTO VALLEYS.

DISCUSSION...THUNDERSTORMS WORKED OVER THE LOWER DESERTS LAST NIGHT
WHICH IS USUALLY PROHIBITIVE FOR THUNDERSTORMS IN THE VALLEYS THIS
AFTERNOON...AND BELIEVE THIS SCENARIO IS CORRECT FROM TUCSON WEST.
TO THE EAST...THUNDERSTORMS SHOULD BE ABLE TO DEVELOP ON THE
MOUNTAINS AND MOVE INTO THE VALLEYS. THE EAST HAS BEEN INHIBITED BY
LOWER MOISTURE VALUES THE LAST FEW DAYS BUT SATELLITE PRECIPITABLE
WATER AND THE EL PASO SOUNDING SHOWS MORE MOISTURE IN PLACE AND
ACTIVITY SHOULD FORM ON THE MOUNTAINS MOVE INTO THE VALLEYS IN THESE
LOCATIONS THIS AFTERNOON. SOUNDING DOES SHOW THAT STORMS WILL HAVE A
HARD TIME GETTING PAST INVERSION AT 400 MB INITIALLY SO LATE START
TO STORMS SEEMS LIKELY. THIS EVENING EASTERN STORMS SHOULD BE ABLE
TO PROPAGATE INTO TUCSON AND WEST ON FAVORABLE MID LEVEL FLOW USING
MID LEVEL CAPE.

THE CHANCE OF SEVERE THUNDERSTORMS AND ONE INCH RAIN REMAINS NEAR
CLIMATOLOGY. THE MOVEMENT OF THE STORMS WILL BE WEST AT 10 TO 15
MPH.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

MODELS INDICATE THAT MONDAY AFTERNOON SHOULD SEE A MORE ORGANIZED
THUNDERSTORM EVENT ACROSS SOUTHEAST ARIZONA. IN ADDITION...MOISTURE
FROM HURRICANE IGNACIO...WHICH WILL MOVE NORTH ALONG THE BAJA COAST
EARLY THIS WEEK AND KEEP A VERY MOIST ATMOSPHERE IN PLACE ACROSS
SOUTHEAST ARIZONA DURING THE WEEK.  A DRIER SOUTHWEST FLOW ALOFT
WILL DEVELOP ACROSS THE DESERT SOUTHWEST OVER THE WEEKEND.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.