Flash Flood Warning 28, NWS Tucson, AZ

SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
200 PM MST THU JUL 23 1998

SYNOPSIS...HIGH PRESSURE ALOFT WILL SINK SOUTHWARD INTO SOUTHERN NEW
MEXICO THROUGH THE END OF THIS WEEK. A MAINLY SOUTH FLOW WILL ALLOW
MONSOONAL MOISTURE TO CONTINUE TO MOVE INTO SOUTHEAST ARIZONA. THE
HIGH ALOFT IS EXPECT DRIFT WESTWARD OVER ARIZONA EARLY NEXT WEEK.
THIS WILL DRY OUT WESTERN ARIZONA WITH TYPICAL AFTERNOON AND EVENING
THUNDERSTORMS CONTINUING INTO THE EASTERN PORTION OF THE STATE.

DISCUSSION...AS EXPECTED IT DID NOT TAKE MUCH CLEARING AND DAYTIME
HEATING FOR THUNDERSTORMS TO DEVELOP. THE GREATEST AMOUNT OF
ACTIVITY THUS FAR HAS BEEN IN COCHISE COUNTY. STORMS WERE MOVING TO
THE NORTHEAST. HEAVY RAIN AND LOCALIZED FLOODING WILL BE THE PRIMARY
HAZARDS THROUGH THE EVENING HOURS.

THE ETA MODEL GUIDANCE TAKES HIGH PRESSURE ALOFT TO SOUTHWEST MEXICO
BY SATURDAY MORNING. THE FLOW ALOFT REMAINS FAVORABLE FOR THE IMPORT
OF MONSOONAL MOISTURE...PARTICULARLY FROM TUCSON EASTWARD. SHOULD
SEE A RETURN TO A MORE TYPICAL AFTERNOON/EVENING THUNDERSTORM CYCLE
WITH TIME. 500 MB HEIGHTS RISE DURING THE PERIOD FOR WARMER
TEMPERATURES.

THE HIGH ALOFT DRIFTS OVER THE STATE EARLY NEXT WEEK WHICH CUTS OFF
MOST OF THE IMPORT OF NEW MOISTURE. PLENTY OF EXISTING MOISTURE TO
WORK WITH FROM CENTRAL PIMA COUNTY EASTWARD SO WILL KEEP THE
STANDARD MONSOON FORECAST GOING FOR ALL AREAS EXCEPT THE FAR WEST.
TUS 4333. OKULSKI

.TWC...NONE

AZZ019-029>035-240700-
SPECIAL WEATHER STATEMENT...SOUTHEAST ARIZONA CONVECTIVE OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1245 PM MST WED JUL 22 1998...THIS PRODUCT IS NOT UPDATED

                        *CONDITIONAL*    *CONDITIONAL*
                AREAL    PROBABILITY   RAIN GREATER THAN   STORM
COUNTY        COVERAGE    OF SEVERE     1.00       2.00    MOTION

COCHISE          60          20          65         30     NE 10
GRAHAM           60          20          65         25     N  10
GREENLEE         60          20          60         25     N  10
TUCSON/ERN PIMA  50          10          55         25     N  10
TOHONO OODHAM   45          10          50         20     N  10
WESTERN PIMA     35          10          40         10     N  10
SOUTHEAST PINAL  50          10          55         20     N  10
SANTA CRUZ       55          10          65         30     NE 10

SYNOPSIS...A BROAD AREA OF DEEP MONSOONAL MOISTURE EXTENDED FROM
NORTHERN SONORA MEXICO TO WESTERN ARIZONA. THUNDERSTORMS WILL
DEVELOP QUICKLY THIS AFTERNOON AND CONTINUE INTO THE EVENING. HEAVY
RAIN NEAR THESE STORMS REMAINS THE PRIMARY CONCERN WITH ONE INCH
RAINFALL AMOUNTS NOT UNCOMMON AND TWO INCH AMOUNTS POSSIBLE. THE GROUND
IN MANY AREAS IS ALREADY SATURDATED SO LOCALIZED FLASH FLOODING IS
POSSIBLE.

*****************************************************************
KEY...
AREAL COVERAGE - PERCENT OF COUNTY OR AREA THAT WILL EXPERIENCE
                  THUNDERSTORMS
PROB OF SEVERE - THE PROBABILITY THAT ANY ONE OF THE STORMS WILL
                  REACH SEVERE LEVELS (DAMAGING WIND AND/OR
                  LARGE HAIL)
RAIN GRTR THAN - THE PROBABILITY THAT ANY ONE OF THE STORMS WILL
                  PRODUCE RAIN EXCEEDING 1 INCH OR 2 INCHES IN
                  ANY LOCATION
STORM MOTION   - GENERAL DIRECTION TO WHICH THE STORMS WILL
                  LIKELY MOVE AND SPEED IN MPH

NOTE...
VALID TIME IS FROM 12:45 PM TO 12 MIDNIGHT OF THE DAY OF ISSUANCE.
THIS PRODUCT IS NOT TO BE USED IN PLACE OF SEVERE THUNDERSTORM OR
FLASH FLOOD WARNINGS OR WATCHES. THIS PRODUCT IS ONLY USED FOR
OUTLOOK PURPOSES. CORRESPONDING GRAPHICS MAY BE FOUND ON THE NWS
TUCSON INTERNET PAGE AT
HTTP://NIMBO.WRH.NOAA.GOV/TUCSON/SWO/SWO.SHTML

END/RJO