Flash Flood Watch 6, NWS Tucson, AZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
1020 AM MST THU AUG 24 2006

.SYNOPSIS...SCATTERED SHOWERS AND THUNDERSTORMS WILL OCCUR TODAY AND
THIS EVENING AS A MOIST FLOW PREVAIL OVER SOUTHEAST ARIZONA. THE
CHANCES FOR THUNDERSTORMS WILL DECREASE THIS WEEKEND AS A GREAT
BASIN DISTURBANCE SPREADS DRIER AIR OVER THE AREA.

&&

.DISCUSSION...KEMX WSR-88D DETECTED SCATTERED TO NUMEROUS MOSTLY
30-55 DBZ ECHOES OVER SE PINAL/EXTREME NE PIMA/WRN GRAHAM COUNTIES
VALID 1715Z. CELL MOVEMENTS WERE NEARLY STATIONARY OR DRIFTING
SLOWLY NEWD. THE REST OF SE AZ WAS VOID OF PRECIP ECHOES. DEWPOINTS
VALID 17Z WERE GENERALLY IN THE LOWER-MID 60S AND THESE VALUES WERE
NEARLY IDENTICAL TO 24 HOURS AGO.

VISIBLE SATELLITE IMAGERY INDICATED CLEAR SKIES ACROSS FAR WRN PIMA
COUNTY AS WELL AS EXTREME ERN SECTIONS...BUT GENERALLY CLOUDY SKIES
OVER ERN PIMA/SE PINAL/WRN GRAHAM COUNTIES. CLOUD TOPS WERE
GENERALLY WARMING DURING THE PAST 1-2 HOURS ASSOCIATED WITH THE
COMPLEX OVER SE PINAL COUNTY. 24/12Z KTUS SOUNDING DEPICTED A VERY
MOIST REGIME...WITH PRECIP WATER VALUE NEAR 1.65 INCHES...AND A
NEARLY SATURATED 800-500 MB LAYER. VERY LIGHT WLY FLOW PREVAILED
THROUGHOUT MUCH OF THE COLUMN. 24/12Z UPPER AIR PLOTS INDICATED HIGH
PRESSURE CENTERED OVER WEST CENTRAL TX...LOW PRESSURE OVER
CHIHUAHUA...AND TROUGH OVER THE PACIFIC NW/NRN ROCKIES REGION. VERY
LIGHT SWLY FLOW PREVAILED OVER SRN AZ.

CONVECTIVE COMPLEX ONGOING JUST NORTH OF THIS FORECAST AREA OVER
CENTRAL AZ WAS AHEAD OF IMPULSE PER WATER VAPOR IMAGERY/SPENES
MESSAGE. ANY SUBSIDENCE BEHIND THIS IMPULSE SHOULD BE SHORT-LIVED
ESPECIALLY GIVEN SERIES OF IMPULSES EMBEDDED WITHIN THE SLY/SWLY
FLOW EXPECTED TO APPROACH SRN AZ LATER THIS AFTERNOON/TONIGHT. GIVEN
THE VERY LIGHT WIND REGIME LOCALLY HEAVY RAINS ARE EXPECTED
PRACTICALLY ANYWHERE WITHIN SE AZ THIS AFTERNOON/EVENING. SCATTERED-
NUMEROUS SHOWERS/TSTMS CENTRAL/ERN SECTIONS WITH ISOLATED SHOWERS/
TSTMS FAR WRN PIMA THIS AFTERNOON/EVENING PER INHERITED FORECASTS IS
REASONABLE.

CONVECTIVE ACTIVITY EXPECTED TO DECREASE ESPECIALLY WRN SECTIONS FRI
AND DOWNWARD TREND TO CONTINUE THIS WEEKEND AS TROUGH DEEPENS OVER
THE GREAT BASIN REGION. MOISTURE PROGGED TO INCREASE EARLY NEXT WEEK
AS SLY FLOW RETURNS IN RESPONSE TO HIGH PRESSURE SYSTEM OVER THE
FOUR CORNERS REGION. PERHAPS SOME DRYING AGAIN LATE NEXT WEEK AS
SWLY FLOW DEVELOPS IN RESPONSE TO TROUGH ALONG THE WEST COAST.
DAYTIME MAX TEMPS THIS FORECAST PERIOD EXPECTED TO REMAIN CLOSE TO
SEASONAL NORMALS FOR LATE AUG.

&&

.AVIATION...TAFS AND TWEBS ADEQUATELY COVER ALL SIGNIFICANT WEATHER
AT KTUS.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...NONE.

&&

BF

WEATHER.GOV/TUCSON

HAZARDOUS WEATHER OUTLOOK...CORRECTED TYPO
NATIONAL WEATHER SERVICE TUCSON AZ
545 AM MST THU AUG 24 2006

AZZ019-029-031>035-251400-
NORTHERN GREENLEE COUNTY-SOUTHEAST PINAL COUNTY-
WESTERN PIMA COUNTY-TOHONO OODHAM NATION-TUCSON METRO/MARANA/GREEN
VALLEY-SANTA CRUZ COUNTY-COCHISE COUNTY-
545 AM MST THU AUG 24 2006

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTH CENTRAL
ARIZONA AND SOUTHEAST ARIZONA.

.DAY ONE...TODAY AND TONIGHT

HIGH PRESSURE CENTERED OVER NORTH CENTRAL TEXAS AND EXTENDING ACROSS
NORTHERN MEXICO WILL ALLOW SOUTH TO SOUTHWEST FLOW TO CONTINUE TO
PULL MOISTURE INTO ARIZONA TODAY. SHOWERS AND THUNDERSTORMS HAVE
ALREADY BEGUN TO DEVELOP ACROSS CENTRAL PORTIONS OF MY FORECAST AREA
FROM SOUTHWEST PINAL COUNTY AND EXTENDING INTO NORTHEAST PIMA
COUNTY...INCLUDING THE TUCSON AREA. THESE STORMS HAVE DEVELOPED
ALONG A BOUNDARY BETWEEN DRY AIR OVER NORTHERN BAJA AND NORTHWEST
SONORA...AND VERY MOIST AIR OVER CENTRAL AND EASTERN ARIZONA. EVEN
THOUGH ORGANIZED SEVERE STORMS ARE NOT ANTICIPATED TODAY...SOME OF
THE STORMS WILL LIKELY APPROACH OR EXCEED SEVERE LEVELS WITH A
POTENTIAL FOR PRODUCING DAMAGING WINDS AND HAIL. THE MID TO UPPER
LEVEL WINDS ARE RATHER WEAK TODAY...SO THE MAIN CONCERN WITH THESE
STORMS WILL BE HEAVY RAIN WHICH COULD RESULT IN LOCALIZED FLOODING.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. HOWEVER...THE FLOW
PATTERN WILL REMAIN FAVORABLE FOR THUNDERSTORMS EACH DAY...BUT WITH
LESS ACTIVITY EXPECTED ON SATURDAY AND SUNDAY.

.SPOTTER INFORMATION STATEMENT...

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

AZZ030-251400-
UPPER GILA RIVER VALLEY-
545 AM MST THU AUG 24 2006

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST ARIZONA.

.DAY ONE...TODAY AND TONIGHT

...A FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 3 PM MST THIS
AFTERNOON...

THE FLASH FLOOD WATCH IS ASSOCIATED WITH A RISE ON THE GILA RIVER AT
DUNCAN. FOR MORE DETAILED INFORMATION CONCERNING THE WATCH REFER TO THE
LATEST ISSUANCE OF THE FLASH FLOOD WATCH UNDER THE HEADER PHXFFATWC
OR REFER TO OUR WEB PAGE AT WWW.WEATHER.GOV/TUCSON.

HIGH PRESSURE CENTERED OVER NORTH CENTRAL TEXAS AND EXTENDING ACROSS
NORTHERN MEXICO WILL ALLOW SOUTH TO SOUTHWEST FLOW TO CONTINUE TO
PULL MOISTURE INTO ARIZONA TODAY. SHOWERS AND THUNDERSTORMS HAVE
ALREADY BEGUN TO DEVELOP ACROSS CENTRAL PORTIONS OF MY FORECAST AREA
FROM SOUTHWEST PINAL COUNTY AND EXTENDING INTO NORTHEAST PIMA
COUNTY...INCLUDING THE TUCSON AREA. THESE STORMS HAVE DEVELOPED
ALONG A BOUNDARY BETWEEN DRY AIR OVER NORTHERN BAJA AND NORTHWEST
SONORA...AND VERY MOIST AIR OVER CENTRAL AND EASTERN ARIZONA. EVEN
THOUGH ORGANIZED SEVERE STORMS ARE NOT ANTICIPATED TODAY...SOME OF
THE STORMS WILL LIKELY APPROACH OR EXCEED SEVERE LEVELS WITH A
POTENTIAL FOR PRODUCING DAMAGING WINDS AND HAIL. THE MID TO UPPER
LEVEL WINDS ARE RATHER WEAK TODAY...SO THE MAIN CONCERN WITH THESE
STORMS WILL BE HEAVY RAIN WHICH COULD RESULT IN LOCALIZED FLOODING.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. HOWEVER...THE FLOW
PATTERN WILL REMAIN FAVORABLE FOR THUNDERSTORMS EACH DAY...BUT WITH
LESS ACTIVITY EXPECTED ON SATURDAY AND SUNDAY.

.SPOTTER INFORMATION STATEMENT...

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