Severe Thunderstorm Warning 36, NWS Tucson, AZ

SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
223 PM MST MON JUL 15 2002

.SYNOPSIS...HIGH PRESSURE ALOFT WILL CONTINUE OVER THE CENTRAL
ROCKIES THIS WEEK. THIS SYSTEM WILL KEEP SOUTHEAST ARIZONA IN A
FAVORABLE MONSOON PATTERN WITH A DAILY RISK OF AFTERNOON AND EVENING
THUNDERSTORMS.

.DISCUSSION...A NARROW BAND OF THICK CLOUDS CAUSED BY SOME MID LEVEL
CONVERGENCE EXTENDED FROM GBN EAST TO TUS AND WILLCOX LIMITING THE
AMOUNT OF SURFACE HEATING THERE. HOWEVER...CLOUD FREE SKIES TO THE
NORTH AND SOUTH OF THIS CONVERGENCE ZONE HAVE GIVEN WAY TO
THUNDERSTORMS...MAINLY ALONG THE EASTERN RIM INTO THE WHITE
MOUNTAINS AND IN THE HUACHUCA MOUNTAINS. THESE STORMS HAVE SHOWED
LITTLE PROGRESS SINCE AROUND NOON...BUT WILL NEED TO KEEP AN EYE ON
THE ACTIVITY IN CASE THEY MAKE A RUN TOWARD THE LOWER DESERTS. THE
STEERING FLOW IS LIGHTER THAN THE PAST FEW DAYS BUT STILL FROM A
FAVORABLE EASTERLY DIRECTION FOR CELLS TO PROPAGATE TOWARD TO LOWER
WESTERN DESERTS. HOWEVER...WOULD NOT EXPECT THIS TO HAPPEN UNTIL
LATE THIS EVENING OR POSSIBLY AFTER MID NIGHT. STILL THINK HEAVY
RAINFALL WILL BE THE MAIN CONCERN FROM THESE STORMS THROUGH TONIGHT.
OTHERWISE...NEXT SEVERAL DAYS STILL LOOK TYPICAL FOR THIS TIME OF
YEAR WITH THE HIGH PRESSURE CELL REMAINING NORTH OF US FOR A
CONTINUED EASTERLY FLOW ALOFT. HOWEVER...MODELS CONTINUED TO SHOW
SIGNS OF DEEPENING THE EASTERN PACIFIC TROUGH AND SHIFTING IT
CLOSER TO THE COAST. THIS WOULD TEND TO LEAD TO SOME DRYING ACROSS
OUR WESTERN ZONES AS A DEEPER SOUTHWESTERLY FLOW ALOFT SPREADS IN.
THUS...WILL CALL FOR LOWER POPS OUT WEST BY THURSDAY AND KEEP THE
HIGHER POPS IN THE EAST.

.TWC...NONE.

AZZ019-029>035-160700-

SOUTHEAST ARIZONA HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1200 PM MST MON JUL 15 2002

.SYNOPSIS...PROBABILITY FOR SEVERE THUNDERSTORMS SLIGHTLY BELOW
CLIMATOLOGY...WITH BETTER CHANCES IN NORTHERN GREENLEE AND NORTHERN
PORTIONS OF GRAHAM COUNTY. PROBABILITIES FOR PRECIPITATION EXCEEDING
ONE INCH WILL BE A GREATER THREAT TODAY EXTENDING FROM SOUTHEAST
PINAL...THROUGH EASTERN PIMA...AND CENTRAL COCHISE COUNTIES.

.DISCUSSION...ALTHOUGH NOT AS ACTIVE OF A DAY IN TERMS OF SEVERE
THUNDERSTORM DEVELOPMENT...DUE TO THE EXTENSIVE COULD DEBRIS LEFT
OVER FROM YESTERDAYS ACTIVITIES.  THERE IS STILL A SLIGHT RISK OF
SEVERE THUNDERSTORM ACTIVITY OVER NORTHERN GREENLEE AND NORTHERN
PORTIONS OF GRAHAM COUNTIES.  THESE AREAS WERE ABLE CLEAR OUT LAST
NIGHT...ALLOWING FOR THE GREATEST HEATING POTENTIAL IN THE COUNTY
WARNING AREA TODAY.  ALSO SOME AREAS TO THE SOUTH IN PORTIONS SANTA
CRUZ AND SOUTHERN PORTIONS OF PIMA COUNTY HAD LESS CLOUD COVER THIS
MORNING.  THE 12Z KTUS SOUNDING WAS NOTHING LIKE THE CAPE OF 4200
J/KG YESTERDAY...BUT THERE IS STILL SOME CAPE TO WORK WITH (2285
J/KG). ALREADY THE WHITE MOUNTAINS AREA SHOWING SOME CU
DEVELOPMENT.  THUNDERSTORMS SHOULD BE ABLE TO MOVE OFF THE RIM
TOWARD THE SOUTHWEST AT 10 MPH.  THE GREATER THREAT TODAY APPEARS TO
BE PRECIPITATION ALONG A LINE EXTENDING FROM SOUTHEAST
PINAL...THROUGH EASTERN PIMA...TO CENTRAL COCHISE COUNTIES. VIS
IMAGERY SHOWS THE DEVELOPMENT OF SHOWERS ALONG A CONVERGENCE AXIS.
12Z SOUNDING ALSO INDICATED AN INCREASE IN PRECIPITABLE WATER
VALUES OF 1.46 INCHES. IT APPEARS THAT MOISTURE IS STILL SEEPING IN
FROM THE SOUTH.  VAD WIND PROFILER FROM YUMA INDICATED SOUTHERLY
WIND COMPONENT UP TO 6000 FEET...HOWEVER THE WINDS HAVE DECREASED
FROM THE DAY BEFORE (ONLY 10 TO 15 KNOTS).  HOWEVER...THERE SEEMS TO
BE SUFFICIENT MOISTURE FOR THESE AREAS MENTIONED ABOVE TO HAVE
PROBABILITIES OF PRECIPITATION EXCEEDING ONE INCH SLIGHTLY HIGHER
THAN CLIMATOLOGY.

THUNDERSTORM MOTION WILL BE TOWARDS THE SOUTHWEST AT 10 MPH.