Severe Thunderstorm Warning 23, NWS Tucson, AZ

SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
215 PM MST MON JUL 21 2003

.SYNOPSIS...STRONG HIGH PRESSURE ALOFT WILL REMAIN CENTERED TO THE
NORTH OF ARIZONA DURING THE NEXT SEVERAL DAYS. A SERIES OF
DISTURBANCES ROTATING AROUND THE HIGH WILL PROVIDE SCATTERED MAINLY
AFTERNOON AND EVENING THUNDERSTORMS THIS WEEK. DAYTIME MAXIMUM
TEMPERATURES WILL BE CLOSE TO SEASONAL NORMALS FOR LATE JULY.

.DISCUSSION...KEMX WSR-88D SCATTERED ISOLATED MOSTLY LESS THAN 40 DBZ
ECHOES VICINITY WHITE/CHIRICAHUA MOUNTAINS AT 2110Z. CELLS WERE
SLOWLY MOVING/PROPAGATING SWWD. VISIBLE SATELLITE IMAGERY INDICATED
GENERALLY CLEAR SKIES ACROSS WRN SECTIONS WITH GENERALLY CUMULIFORM
CLOUDINESS OVER ERN SECTIONS. DEWPOINTS WERE IN THE MID 50S-LOWER
60S F WHICH WERE NEARLY IDENTICAL TO 24 HOURS AGO. ACTIVITY SHOULD
INCREASE IN COVERAGE AND INTENSITY DURING THE NEXT FEW HOURS AS WEAK
SHORTWAVE TROUGH OVER W CENTRAL NM ROTATES SWWD ACROSS UPPER HIGH
CENTERED OVER NV. BELIEVE SHOWERS/THUNDERSTORMS MAY CONTINUE BEYOND
MIDNIGHT TUS VICINITY WWD AND WILL REFLECT SUCH IN ZONE/GRIDS. UPPER
HIGH PROGGED TO MIGRATE SLOWLY EWD THIS WEEK. 21/12Z GFS SOLUTION
DEPICTS YET ANOTHER IN SERIES OF SHORTWAVE TROUGHS TO ROTATE AROUND
PERIPHERY OF HIGH ACROSS SRN AZ TUE NIGHT/EARLY WED. PER COORD WITH
WFO PHX BELIEVE SHOWERS/THUNDERSTORMS WILL AGAIN DEVELOP TUE
AFTERNOON BUT ACTIVITY MAY LINGER PARTICULARLY CENTRAL/WRN SECTIONS
TUE NIGHT. THUS HAVE ADJUSTED INHERITED GRIDDED FIELDS TO REFLECT
CHANCE-TYPE POPS TUE AFTERNOON/EVENING AND 10-20 PERCENT POPS UNTIL
AROUND DAYBREAK WED. AFTER THAT UPPER HIGH PROGGED TO BECOME CENTERED
OVER SRN CO/NRN NM. SUBTLE CHANGE IN PATTERN AS ASSOCIATED MID-
LEVEL STEERING FLOW TO BECOME INCREASINGLY SELY. THUS ACTIVITY MAY
BE LESSENED WRN SECTIONS BUT STANDARD-FOR-SEASON AFTERNOON/EVENING
SHOWERS/THUNDERSTORMS TUS VICINITY EWD. DAYTIME MAX TEMPS INTO EARLY
NEXT WEEK SHOULD REMAIN CLOSE TO SEASONAL NORMALS FOR LATE JULY.  BF

.TWC...NONE.

AZZ019-029>035-221400-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1130 AM MST MON JUL 21 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST ARIZONA

.DAY ONE...TODAY

SYNOPSIS...ANOTHER IMPULSE WILL MOVE FROM NORTH CENTRAL NEW MEXICO
THIS AFTERNOON INTO SOUTHWEST ARIZONA THIS EVENING. THIS IS EXPECTED
TO BRING AN UPSWING IN SHOWER AND THUNDERSTORM ACTIVITY TO SOUTHEAST
ARIZONA TODAY. OTHERWISE...THE LARGE SCALE WEATHER PATTERN REMAINS
FAVORABLE THROUGH THE REST OF THE WEEK FOR SCATTERED AFTERNOON AND
EVENING THUNDERSTORMS.

.DISCUSSION...MORNING KTUS UPPER AIR SOUNDING INDICATES ABUNDANT
MOISTURE...WITH PRECIPITABLE WATERS OF 1.42 INCHES. GOES TOTAL
PRECIPITABLE WATER SATELLITE IMAGERY INDICATES HIGHER VALUES FROM
TUCSON WESTWARD...ALTHOUGH RAOBS FROM AROUND THE REGION SHOW MORE
THAN SUFFICIENT MOISTURE IN PLACE OVER MUCH OF THE SOUTHWESTERN
UNITED STATES. THE 12Z KTUS PROFILE ALSO WAS MORE UNSTABLE VERSUS 24
HOURS AGO...WITH A LIFTED INDEX NEAR MINUS 5 AND AN UNMODIFIED
SURFACE-BASED CAPE VALUE OF 2458 J/KG. SURFACE DEWPOINTS ARE
CURRENTLY IN THE UPPER 50S TO MID 60S ACROSS SOUTHEAST ARIZONA...
WHICH IS ABOUT 2 TO 5 DEGREES HIGHER THAN THIS TIME YESTERDAY.

CURRENT LARGE SCALE PATTERN HAS A STRONG RIDGE OF HIGH PRESSURE OVER
THE WESTERN UNITED STATES...WITH THE HIGH CENTERED OVER WEST CENTRAL
NEVADA. THIS FLOW PATTERN PUTS SOUTHERN ARIZONA...WHICH IS ON THE
SOUTHERN PERIPHERY OF THE HIGH...IN A FAVORABLE POSITION FOR
THUNDERSTORM DEVELOPMENT. A WEAK DISTURBANCE ROTATING AROUND THE
HIGH WILL BRING SOME DYNAMICS TO FOCUS CONVECTION LATER THIS
AFTERNOON AND EVENING. THIS PIECE OF ENERGY IS FORECASTED TO DROP
SOUTHWEST FROM NEW MEXICO INTO ARIZONA TONIGHT. THIS SHOULD AID IN
INITIATING CONVECTION ALONG THE EASTERN RIM AND WHITE MOUNTAINS THIS
AFTERNOON...WITH THE STORMS THAT DO DEVELOP IN THE HIGHER TERRAIN
HAVING A GOOD CHANCE OF PROPAGATING INTO THE LOWER AND CENTRAL
DESERTS LATER THIS EVENING...AS THE DISTURBANCE PUSHES SOUTHWEST.
WEATHER CONCERNS TODAY WILL BE ISOLATED STRONG WIND GUSTS...SMALL
HAIL AND LOCALIZED HEAVY RAINFALL. DUE TO THE AMOUNT OF MOISTURE IN
THE ATMOSPHERE THE POTENTIAL FOR HEAVY RAINFALL IN EXCESS OF ONE
INCH WILL BE MODERATE...ESPECIALLY OVER SOUTHERN AREAS OF SOUTHEAST
ARIZONA...FROM WESTERN COCHISE COUNTY...WEST ACROSS SANTA CRUZ AND
PIMA COUNTIES.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH MONDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

SUFFICIENT MOISTURE WILL BE IN PLACE FOR A STANDARD SUMMERTIME
THUNDERSTORM 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.