Flash Flood in Arizona, July 22, 2003

SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
240 PM MST TUE JUL 22 2003

.SYNOPSIS...WITH HIGH PRESSURE ESTABLISHED TO OUR NORTH...SOUTHEAST
ARIZONA WEATHER WILL CONTINUE TO BE MOIST AND UNSTABLE INTO THE
COMING WEEKEND. EXPECT SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS UNTIL FURTHER NOTICE.

.DISCUSSION...KEMX WSR-88D DETECTED SCATTERED STRONG CELLS ACROSS
THE WHITE MOUNTAINS MOVING WWD AROUND 15-20 KTS AT 2120Z. OTHER
ISOLATED ECHOES EXTENDED FROM THE CHIRICAHUAS-FAR SW NM AND JUST S
OF THE INTERNATIONAL BORDER ACROSS NRN SONORA. VISIBLE SATELLITE
IMAGERY INDICATED RAPIDLY DEVELOPING CUMULIFORM CLOUDINESS MAINLY
NEAR MOUNTAINS AND ALSO ACROSS WRN SECTIONS. DEWPOINTS WERE IN THE
MID 50S-LOWER 60S F WHICH WERE NEARLY IDENTICAL TO 24 HOURS AGO.
EXPECT SHOWERS/THUNDERSTORMS WILL CONTINUE TO INCREASE IN COVERAGE
DURING THE NEXT FEW HOURS. BEST CHANCE OF PRECIP TUS VICINITY SHOULD
BE AFTER 01-02Z OR SUCH PER LATEST MESO ETA/MM5 OUTPUT. THUS WILL
OPT FOR SCATTERED EVENING SHOWERS/THUNDERSTORMS WITH EXPECTATION OF
ACTIVITY WANING ERN SECTIONS EARLY THOUGH PERHAPS LINGERING ACROSS
CENTRAL/WRN SECTIONS UNTIL AFTER MIDNIGHT. UPPER HIGH CENTERED
INITIALLY OVER ERN NV TO MIGRATE TOWARD FOUR CORNERS REGION BY
THUR. GENERALLY ELY FLOW TO CONTINUE WITH MAINLY AFTERNOON/EVENING
SHOWERS/THUNDERSTORMS DURING THE NEXT SEVERAL DAYS. DID NOTE THAT
22/12Z GFS PROGGED VORT MAXES TO MOVE AROUND PERIPHERY OF UPPER HIGH
WWD ACROSS SE AZ/NRN SONORA REGION LATE FRI-EARLY SAT. TAKEN AT FACE
VALUE FRI AFTERNOON/NIGHT WOULD HAVE INCREASED CONVECTIVE POTENTIAL.
HOWEVER WILL TEMPER THAT ENTHUSIASM SOMEWHAT AT THIS TIME WITH MORE
CONSERVATIVE APPROACH UNTIL MODEL CONTINUITY ESTABLISHED. HAVE
INCREASED DAYTIME MAX TEMPS SLIGHTLY MOST LOCALES WED-THUR VERSUS
PREVIOUS FORECASTS. ALSO APPEARS MRF MOS GUIDANCE MAX TEMPS HAVE
BEEN TOO LOW RECENTLY. THUS BELIEVE DAYTIME MAX TEMPS DURING THE
WEEKEND/EARLY NEXT WEEK WILL BE SLIGHTLY ABOVE SEASONAL NORMALS FOR
LATE JULY.  BF

.TWC...NONE.

AZZ019-029>035-231400-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1200 PM MST TUE JUL 22 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST ARIZONA

.DAY ONE...TODAY

SYNOPSIS...THERE IS NO SIGNIFICANT CHANGE IN THE MOISTURE PROFILE
ACROSS THE STATE TODAY AND THUNDERSTORMS ARE EXPECTED TO DEVELOP
ACROSS THE EASTERN MOUNTAINS AND MOVE WESTWARD. THESE THUNDERSTORMS
MAY WORK INTO THE VALLEYS TODAY AS THERE WAS LESS COOLING IN THE
VALLEYS THIS MORNING. OTHERWISE...THE LARGE SCALE WEATHER PATTERN
REMAINS FAVORABLE THROUGH THE REST OF THE WEEK FOR SCATTERED
AFTERNOON AND EVENING THUNDERSTORMS.

.DISCUSSION...MINOR CHANGES ON TUCSON SOUNDING MAY POINT TO A MORE
ACTIVE DAY IN THE VALLEYS AND OUT INTO THE LOW DESERTS. YESTERDAY
LOW DESERTS HAD A FAIR AMOUNT OF COOLING FROM THE STORMS ON SUNDAY.
ALTHOUGH IT LOOKED FROM THE SATELLITE THAT A FAIR AMOUNT OF STORMS
OCCURRED YESTERDAY THEY GENERALLY STAYED OUT OF THE VALLEYS AND LOW
DESERTS ALTHOUGH ANVIL RAINS FELL IN PHOENIX AND TUCSON. THE AREA
FROM CENTRAL AND WESTERN PIMA COUNTY WERE BASICALLY UNTOUCHED. ALOFT
IS NEUTRAL SINCE THERE IS NO FEATURE TO AID CONVECTION ALTHOUGH
THERE IS NOT A BIG NEGATIVE FACTOR. MM5 MODEL THIS MORNING INDICATED
A TAD LATER START THAN NORMAL BUT DID MOVE THE STORMS INTO THE
VALLEYS AND DESERTS WITH STORMS MOVING INTO TUCSON AROUND 5 PM.

MID LEVEL WINDS ARE FAIRLY BRISK AND STORM MOTION SHOULD BE FAIRLY
QUICK TOWARDS THE WEST...15 MILES PER HOUR. ALSO...WATER VAPOR
SATELLITE IMAGERY INDICATES MID LEVEL DRY AIR MOVING INTO THE STATE
FROM NEW MEXICO. THIS MAY PROMOTE HAIL GROWTH WITH STORMS AND
INCREASE THE CHANCE OF SEVERE WEATHER ASSOCIATED WITH STORMS. DUE TO
THE AMOUNT OF MOISTURE IN THE ATMOSPHERE THE POTENTIAL FOR HEAVY
RAINFALL IN EXCESS OF ONE INCH WILL BE MODERATE.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH TUESDAY.

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

SUFFICIENT MOISTURE WILL BE IN PLACE FOR A STANDARD SUMMERTIME
THUNDERSTORM SEASON FORECAST. EXPECT SCATTERED MAINLY AFTERNOON AND
EVENING SHOWERS AND THUNDERSTORMS.

.SPOTTER INFORMATION STATEMENT...

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