Severe Thunderstorm Warning 29, NWS Tucson, AZ

SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
930 AM MST MON AUG 7 2000

SYNOPSIS...THE ATMOSPHERE OVER SOUTHEAST ARIZONA WILL REMAIN VERY
MOIST FOR THE NEXT SEVERAL DAYS. AFTERNOON AND EVENING THUNDERSTORMS
WILL DEVELOP EACH DAY IN THE MOUNTAINS WITH SOME STORMS MOVING INTO
VALLEY LOCATIONS. SOME OF THE STORMS WILL BE STRONG WITH HEAVY
RAINFALL AND GUSTY WINDS.

DISCUSSION...LIKE YESTERDAY...DIFFICULT TO DETERMINE IF STORMS WILL
WANT TO MOVE OFF MOUNTAINS TODAY. PHX AND TUS SOUNDINGS SHOWED A LOT
OF COOLING IN THE LOWER LAYERS BUT WONDER HOW REPRESENTATIVE THIS IS
GIVEN LOW DESERTS HAD NO STORMS AND BOTH SOUNDING SIGHTS MAY HAVE
BEEN CONTAMINATED BY STORMS. SURGE THAT STARTED SUNDAY MORNING STILL
UNDERWAY AND EVEN DEEPER THAN SUNDAY. ALTOCU DECK WILL LIMIT HEATING
IN SOME AREAS ALTHOUGH IT SEEMS TO BE ERODING AWAY QUICKER TODAY
THAN SUNDAY. STORMS LAST NIGHT DROPPED COPIOUS AMOUNTS OF PRECIP
SOUTH OF US AND IN MEXICO...BUT THIS WAS LIMITED TO HIGHER TERRAIN
AND SOME VALLEY LOCATIONS NEAR THE BORDER.

ANALYSIS SHOWS HIGH LOW LEVEL MOISTURE VALUES ACROSS SOUTHERN HALF
OF ARIZONA. WEAK WINDS ALOFT WILL MAKE STORM MOTION SLOW. ETA/NGM
DIFFER A LITTLE ON UPPER LEVEL WINDS THIS AFTERNOON BUT A FAVORABLE
WEST WIND AT 250 MB SEEMS TO BE IN PLACE. STORM MOTION WILL BE
RELATIVELY SLOW WITH ONLY 10 KNOTS OF WIND THROUGH THE LAYER AND
EVEN WEAKER THERMAL WINDS. 500 MB TEMPS COLD ENOUGH TO SUPPORT HAIL
BUT BELIEVE SIGNIFICANT WEATHER WILL BE WET MICROBURST AND HEAVY
RAIN POTENTIAL. MODELS HINT AT STORMS MOVING INTO VALLEYS LATE
AFTERNOON AND EVENING. RIGHT NOW KIND OF UNDECIDED ON WHAT TO DO BUT
LEANING TOWARDS AN UP DAY FOR VALLEY LOCATIONS. WILL LEAVE ZONES
ALONE FOR NOW AND MONITOR SITUATION.

.TWC...NONE.

AZZ019-029>035-080600-
HAZARDOUS WEATHER OUTLOOK...SOUTHEAST ARIZONA CONVECTIVE OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1045 AM MST MON AUG 7 2000

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

COCHISE              55          10         20        10      W   5
GRAHAM               55          15         25        10     SW  10
GREENLEE             70          20         35        15     SW  10
TUCSON/ERN PIMA      50          25         35        20      W   5
TOHONO OODHAM       40          25         35        15      W  10
SOUTHEAST PINAL      45          20         40        20      W  10
WESTERN PIMA         30          10         15         5      W  10
SANTA CRUZ           55          10         15        10      W   5

SYNOPSIS...PLENTY OF MOISTURE IN PLACE FOR SLOW MOVING STORMS
WHICH WILL INCREASE POTENTIAL FOR HEAVY RAIN...ALTHOUGH WET
MICROBURST IS ALSO POSSIBLE. STORMS WILL DEVELOP IN MOUNTAINS AND
MOVE WEST INTO VALLEYS BY LATE AFTERNOON.
*****************************************************************
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...PRODUCT IS NOT UPDATED.
VALID TIME IS FROM 10:45 AM 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://WWW.WRH.NOAA.GOV/TUCSON/THUNDER/SWO.SHTML

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