Severe Thunderstorm Warning 45, NWS Tucson, AZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
230 PM MST WED AUG 11 2004

SOUTHEAST ARIZONA FORECAST DISCUSSION

.SYNOPSIS...HIGH PRESSURE ALOFT OVER NEVADA AREA AND WILL RESULT
IN A LOW GRADE MONSOON TODAY AND THURSDAY WITH ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORM ACROSS SOUTHEAST ARIZONA. A SERIES OF UPPER
LEVEL DISTURBANCES IS EXPECTED TO BRING AN INCREASE IN THUNDERSTORM
ACTIVITY FRIDAY AND SATURDAY. BY EARLY NEXT WEEK...DRIER CONDITIONS
ARE EXPECTED AS THE UPPER HIGH SHIFTS SOUTH INTO MEXICO.

&&

.DISCUSSION...ISOLATED THUNDERSTORMS ALREADY DEVELOPING ACROSS THE
HIGHER ELEVATIONS WITH A FEW BEGINNING TO MOVE INTO THE VALLEY.
THUNDERSTORMS ALSO STARTING TO MOVE SOUTHWEST TOWARD SAFFORD.  KEMX
RADAR REFLECTIVITY SHOWING THE STRONGER STORMS SOUTH OF TUCSON. THE
18Z KTUS SOUNDING WAS UNSTABLE WITH A LIFTED INDEX OF -7.4 AND AN
UNMODIFIED CAPE OF 2300 J/KG. THE 700MB FLOW WAS FROM THE NORTHEAST
AT 10 KNOTS...WHICH WOULD EASILY ALLOW STORMS TO PUSH OFF THE
MOUNTAINS. THE SOUNDING WAS STILL RATHER DRY IN FROM THE SURFACE UP
TO 600MB...THUS THE MAIN THREAT TODAY WILL BE DAMAGING WINDS. GOES
PW SHOWS THE DEEPER MOISTURE IN WESTERN PORTIONS OF THE CWA...THUS A
FEW STORMS MAY ALSO PRODUCE SOME HEAVY PRECIPITATION (AGAIN WITH
SEVERE WINDS BEING THE MAIN THREAT).EXPECTING CONTINUED THUNDERSTORM
ACTIVITY FOR THURSDAY AFTERNOON AND EVENING (COMPARABLE TO TODAYS
ACTIVITY). HOWEVER...THERE WILL BE AN UPSWING IN THUNDERSTORM
ACTIVITY ON FRIDAY AND SATURDAY AS A SERIES OF UPPER LEVEL
DISTURBANCES MOVES AROUND THE HIGH PRESSURE SYSTEM.  ACTUALLY GOING
ABOVE MONSOON GRADE POPS IN MOST LOCATIONS...WHICH SEEMS LIKE A
FIRST IN THE SEASON ON THE NON-SOON. HOWEVER...MODELS SHOWS DRYING
TREND IN THE EXTENDED FORECAST STARTING AS EARLY AS MONDAY.  WILL
KEEP LOW GRADE POPS IN FROM MONDAY THROUGH WEDNESDAY WITH THE BEST
CHANCE FOR THUNDERSTORMS OVER THE HIGHER TERRAIN.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...NONE.

MG

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1205 PM MST WED AUG 11 2004

AZZ019-029>035-120700-
NORTHERN GREENLEE COUNTY-UPPER GILA RIVER VALLEY-COCHISE COUNTY-
SOUTHEAST PINAL COUNTY-TUCSON METRO/MARANA/GREEN VALLEY-
SANTA CRUZ COUNTY-TOHONO OODHAM NATION-WESTERN PIMA COUNTY-
1205 PM MST WED AUG 11 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST ARIZONA

.DAY ONE...TODAY

SYNOPSIS...SOMEWHAT MORE ACTIVITY EXPECTED TODAY THOUGH COVERAGE
WILL ONLY BE ISOLATED FROM TUCSON VICINITY WESTWARD WITH SCATTERED
AFTERNOON AND EVENING THUNDERSTORMS ACROSS EASTERN SECTIONS. APPEARS
THAT THE MAIN THREAT WILL BE FROM STRONG AND POSSIBLY DAMAGING WINDS
VERSUS HEAVY RAIN.

DISCUSSION...KEMX WSR-88D DETECTED ISOLATED THUNDERSTORMS AT NOON
OCCURRING NEAR THE WHITE MOUNTAINS VICINITY HANNAGAN MEADOW. THE
REST OF SOUTHEAST ARIZONA WAS VOID OF PRECIPITATION ECHOES. LOW
LEVEL MOISTURE INCREASE OCCURRED OVERNIGHT AND THIS MORNING. THE
SPECIAL 18Z KTUS SOUNDING INDICATED A SLIGHT INCREASE IN MOISTURE
VERSUS 24 HOURS AGO...AND WAS CONSIDERABLY MORE UNSTABLE VERSUS THE
SOUNDING AT MIDDAY TUESDAY. PRECIPITABLE WATER VALUE WAS NEAR 1.20
INCH WITH LIFTED INDEX VALUE NEAR MINUS 7. SHOWERS AND THUNDERSTORMS
SHOULD CONTINUE TO DEVELOP ALONG THE MOGOLLON RIM THIS AFTERNOON AND
OTHER THUNDERSTORMS SHOULD ALSO DEVELOP NEAR THE MOUNTAINS EAST OF
TUCSON. THE STORMS ARE EXPECTED TO MOVE AND/OR PROPAGATE TOWARD THE
SOUTHWEST DURING THE REMAINDER OF THE AFTERNOON AND EVENING. THE
MAIN CONCERN OR THREAT ASSOCIATED WITH THESE STORMS WILL BE MAINLY
STRONG AND POSSIBLY DAMAGING WIND GUSTS PARTICULARLY GIVEN THE
FAIRLY DRY ENVIRONMENT IN THE LOWER LEVELS. THE THREAT FOR HEAVY
RAIN IS LOW. RAINFALL AMOUNTS OF ONE-TENTH TO ONE-HALF OF AN INCH
WITH ISOLATED AMOUNTS OF UP TO ONE INCH CAN BE EXPECTED IN THE
HIGHER TERRAIN. RAINFALL AMOUNTS OF LESS THAN TWO-TENTHS OF AN INCH
ARE EXPECTED IN THE VALLEYS.

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

ISOLATED SHOWERS AND THUNDERSTORMS ARE EXPECTED AGAIN THURSDAY. AN
INCREASE IN THUNDERSTORMS IS EXPECTED FRIDAY WITH SCATTERED
THUNDERSTORMS ACROSS MAINLY EASTERN SECTIONS SATURDAY. A DRYING
TREND IS FORECAST STARTING SUNDAY AND CONTINUING THROUGH THE MIDDLE
OF NEXT WEEK WITH ANY THUNDERSTORMS OF SIGNIFICANCE LIMITED TO ONLY
NEAR THE MOUNTAINS OF FAR SOUTHEAST ARIZONA.

.SPOTTER INFORMATION STATEMENT...

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

BF