Flash Flood in Arizona, August 20, 2003

SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
200 PM MST WED AUG 20 2003

.SYNOPSIS...HIGH PRESSURE OVER THE CENTRAL AND SOUTHERN ROCKIES WILL
MAINTAIN A FAVORABLE MOIST FLOW FOR SCATTERED SHOWERS AND
THUNDERSTORMS THROUGH THE WEEK.

.DISCUSSION...12Z KTUS SOUNDING PLENTY WET WITH PRECIPITABLE WATER
NEAR 1.48. BOUNDARY LAYER HAS RECOVERED SOMEWHAT...BUT H5 A MEDIOCRE
-5 OR SO FOR A TEMPERATURE. STILL...THIS DOES MAKE FOR A LESS STABLE
TEMPERATURE PROFILE THAN YESTERDAYS RELATIVE DOWN DAY CONVECTION
WISE. WEVE HAD A DECENT TIME OF IT FIRING CONVECTION OVER THE
MOUNTAINS...BUT LITTLE SIGN OF SUPPORTING MANY VALLEY STORMS YET.
EXPECT THIS TO CHANGE LATER IN THE AFTERNOON WITH AN EMPHASIS ON
EASTERN AREAS HAVING THE BEST COMBINATION OF INSTABILITY AND
MOISTURE. ALL AREAS A FLASH FLOOD CONCERN WHEN AVAILABLE MOISTURE
LIKE THIS...JUST NOT SURE IF WELL GET THE COVERAGE TO WARRANT AN
ADVISORY.

PLENTY OF MOISTURE WITH WEAK SURGE KEEPING DEWPTS HIGH ON THE LOWER
DESERTS AND GOES SOUNDER ESTIMATES RANGING FROM ABOUT 1 TO 1.2 NEAR
THE NEW MEXICO BORDER TO OVER 1.5 OVER THE LOWER DESERTS. ON THE
LARGE SCALE...HIGH CENTER WILL CONSOLIDATE AND SHIFT A LITTLE
NORTHWARD WITH OUR SOUTHERLY FLOW TO GAIN A PARTIAL EASTERLY
COMPONENT AS IT DOES. SOME WIGGLES AND WEAKNESSES IN THE FLOW...BUT
NO BIG WAVE EVIDENT OR IMMINENT. COULD SEE AN UPSWING IN ACTIVITY
FRIDAY WITH ADDITIONAL FOCUS FROM THE SOUTHEAST...BUT OTHERWISE A
BROADBRUSH CHANCE OF AFTERNOON AND EVENING CONVECTION LOOKS FINE. M

.TWC...NONE.

AZZ019-029>035-211400-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1155 AM MST WED AUG 20 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST ARIZONA

.DAY ONE...TODAY

SYNOPSIS...PLENTY OF MOISTURE IS IN PLACE FOR AFTERNOON AND EVENING
THUNDERSTORMS OVER THE MOUNTAINS WITH SOME MOVING INTO THE VALLEYS
BY LATE AFTERNOON AND EVENING. THESE STORMS WILL BE CAPABLE OF
PRODUCING LOCALLY HEAVY RAIN AND STRONG WINDS. TEMPERATURES ALOFT
ARE A LITTLE TOO WARM FOR HAIL.

DISCUSSION....WITH ALL OF THIS MOISTURE IT MAY BE PRUDENT TO LEAN
TOWARDS A HEAVY RAIN EVENT...BUT JUST CAN NOT FIND ANY KICKER TO
GET STORMS TO ORGANIZE. THAT MEANS THAT STORMS WILL HAVE LOCAL
AFFECTS WORKING...SOMETHING ALMOST IMPOSSIBLE TO PREDICT. STORMS
THAT FORM AND CAN GET OFF THE MOUNTAINS WILL HAVE THE CAPABILITY OF
PRODUCING HEAVY RAIN AND POSSIBLY SOME STRONG WINDS DUE TO
PRECIPITATION LOADING...BUT -5C AT 500 MB USUALLY IS PROHIBITIVE FOR
MAKING LARGE HAIL.

THE PROBABILITY OF ONE INCH RAIN AND SEVERE WEATHER IS SLIGHTLY
ABOVE NORMAL FOR ALL OF SOUTHEAST ARIZONA. MOVEMENT WILL BE
NORTH AT 10 TO 15 MPH.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

MODELS SUGGEST A SIGNIFICANT INCREASE IN THUNDERSTORM ACTIVITY
FRIDAY AFTERNOON AND EVENING...OTHERWISE TYPICAL AFTERNOON AND
EVENING THUNDERSTORM ACTIVITY IS EXPECTED INTO NEXT WEEK.

.SPOTTER INFORMATION STATEMENT...

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