Flash Flood Warning 11, NWS Tucson, AZ

SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
230 PM MST FRI JUL 20 2001

SYNOPSIS...LOW PRESSURE WILL REMAIN ALONG THE WEST COAST WITH HIGH
PRESSURE OVER THE SOUTHERN PLAINS. THIS PATTERN WILL CONTINUE TO
PUSH MOISTURE INTO SOUTHEAST ARIZONA. EXPECT SCATTERED AFTERNOON
AND EVENING THUNDERSTORMS THROUGH THE WEEKEND AND INTO NEXT WEEK.

DISCUSSION...IN THE NEAR TERM CLOUDS HAVE HELD DOWN TEMPS OVER THE
EASTERN COUNTIES WITH ONLY ISOLATED CONVECTION THIS AFTN. CLOUDS
ARE BREAKING UP AND WITH SO MUCH MOISTURE AROUND WILL LIKELY SEE
SCATTERED ACTION THIS EVENING. MAIN TSTMS HAVE BEEN WHERE EARLIER
THOUGHT...WESTERN EDGE OF THE CLOUDS WHERE GOOD HEATING TOOK PLACE
...SANTA CRUZ VALLEY. TO THE WEST MOISTURE SURGING FROM MEXICO HAS
DEEPENED THE MOISTURE PROFILE...THIS SEEN ON SATELLITE WHERE A CU
FIELD HAS FORMED AND THE PRECIP WATER SATELLITE SHOWING THE OVER 1
INCH AMOUNT HAS EXPANDED RAPIDLY UP FROM THE SOUTH. SHOULD SEE SOME
ACTION TO THE WEST IN THIS INCREASING MOISTURE AND FROM OUTFLOWS
FROM THE SANTA CRUZ VALLEY TSTMS. FOR SATURDAY DEEP MOISTURE WILL
BE IN PLACE AND SHOULD SEE AFTN TSTMS MOST AREAS.

LONGER TERM...WEST COAST MEAN TROF STAYS IN PLACE BUT WEAKENS WHILE
HIGH MEANDERS FROM THE SOUTHERN PLAINS TO NEW MEXICO. LITTLE CHANGE
IN THE PATTERN FOR LITTLE CHANGE IN TSTM POTENTIAL. WILL LEAVE
EXTENDED ALONE WITH AFTN/EVE TSTMS THRU THE PERIOD.

.TWC...NONE.

AZZ019-029>035-210700-

SOUTHEAST ARIZONA HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
12 NOON MST FRI JUL 20 2001

.SYNOPSIS...SOUTHEAST ARIZONA WILL REMAIN THE DIVIDING LINE BETWEEN
DRIER AIR OVER FAR WESTERN ARIZONA AND DEEP MONSOON MOISTURE TO THE
EAST...WITH LOW PRESSURE ALONG THE WEST COAST AND HIGH PRESSURE OVER
THE SOUTHERN PLAINS. A GULF SURGE HAS STARTED AND IS PUSHING LOW
LEVEL MOISTURE INTO THE LOWER DESERTS.

.DISCUSSION...THE MORNING STARTED OUT CLOUDY EAST OF TUCSON...WHICH
WILL DELAY THE ONSET OF CONVECTION A BIT...AND MOSTLY SUNNY FROM
TUCSON WEST...WHERE CONVECTION ALREADY HAS DEVELOPED OVER THE HIGHER
TERRAIN. SURFACE DEWPOINTS ARE UP...INTO THE UPPER 50S TO THE MIDDLE
60S...THANKS TO LOW LEVEL MOISTURE FROM MCS ACTIVITY LAST NIGHT IN
SONORA. THE BIGGEST CHANGE TODAY IS THAT A GULF SURGE IS CURRENTLY
IN PROGRESS INTO THE LOWER DESERTS. A MORNING PIBAL FROM PUERTO
PENASCO (ROCKY POINT) SHOWED DEEP SOUTHEAST FLOW OF 25 KTS UP TO
5000 FEET. THE YUMA SURFACE DEWPOINT HAS REFLECTED THIS SURGE OF
MOISTURE AS IT HAS RISEN IN THE PAST 24 HOURS FROM THE UPPER 30S TO
THE LOWER 60S. NOT SURE HOW FAR EAST THIS INFLUX OF MOISTURE HAS
ADVECTED...WHICH MAY BRING A BETTER CHANCE TO WESTERN PIMA COUNTY
THIS EVENING.

THE RISK OF FLASH FLOODING WILL BE WELL ABOVE CLIMATOLOGY...
ESPECIALLY IN EASTERN PIMA COUNTY...SANTA CRUZ COUNTY AND SOUTHEAST
PINAL COUNTY ALONG WITH THE WESTERN PARTS OF GRAHAM AND COCHISE
COUNTIES. THE RISK OF SEVERE THUNDERSTORMS IS SLIGHTLY HIGHER THAN
CLIMATOLOGY.