Severe Thunderstorm Warning 67, NWS Tucson, AZ

SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
230 PM MST TUE AUG 12 2003

.SYNOPSIS...TEMPERATURES WILL FINALLY DROP BACK TO NEAR OR BELOW
SEASONAL NORMALS THE SECOND HALF OF THE WEEK AS AN UNUSUALLY STRONG
LOW PRESSURE SYSTEM MOVES WESTWARD FROM TEXAS INTO ARIZONA. AS IT
DOES...EXPECT A STRONG UPSWING IN THUNDERSTORM ACTIVITY AS WELL.

.DISCUSSION...ISOLATED THUNDERSTORMS HAVE DEVELOPED THIS AFTERNOON
MAINLY OVER/NEAR THE HIGHER TERRAIN.SURFACE DEWPOINTS HAVE MIXED OUT
INTO THE LOWER TO MID 50S...WHICH IS KEEPING THE STORMS NEAR THE
HIGHER TERRAIN. MY THOUGHT PROCESS HAS CHANGED FROM THIS MORNINGS
DISCUSSION IN RESPECTS TO ACTIVITY THIS EVENING AND OVERNIGHT. WEAK
WAVE/DISTURBANCE...WHICH MODELS HAVE PICKED UP ON...IS MOVING DOWN
WESTERN NEW MEXICO THIS AFTERNOON...AND IS EXPECTED TO MOVE INTO
SOUTHWEST NEW MEXICO OVERNIGHT. MODELS ARE SHOWING INCREASED OMEGA
FIELDS...WITH A BULLSEYE ON COCHISE COUNTY...LATER TONIGHT. WILL GO
WITH ISOLATED POPS DURING THE EVENING HOURS...AND THEN INCREASE THEM
IN SCATTERED CATEGORY OVERNIGHT. MAIN THREAT FROM STORMS IS STRONG
GUSTY WINDS DUE TO
INVERTED-V SOUNDING PROFILES. IF ANY STORMS MOVE OUT WEST...THERE IS
THE POTENTIAL FOR LOCALLY HEAVY RAIN DUE TO DEEPER MOISTURE.

ACTIVITY TO PICK UP NEXT SEVERAL DAYS DUE TO APPROACHING STRONG
UPPER LOW...WHICH IS CURRENTLY OVER EAST TEXAS. VORT MAX...CURRENTLY
NEAR TULSA...WILL MERGE WITH THE EAST TEXAS UPPER LOW...AND START
THE MIGRATION WEST. THIS UPPER LOW WILL BE JUST EAST OF THE TEXAS
BIG BEND BY 5 PM WEDNESDAY...AND OVER NORTHERN CHIHUAHUA (SOUTH OF
EL PASO) BY 5 PM THURSDAY. VERY GOOD PATTERN FOR RIM SHOTS WEDNESDAY
AND THURSDAY...WITH STORMS MIGRATING OFF THE MOUNTAINS INTO THE
LOWER DESERTS EACH NIGHT. CURRENT HOT TEMPERATURES OVER THE PAST
WEEK WILL GIVE WAY TO BELOW NORMAL TEMPERATURES LATER THIS WEEK.

THE ABOVE MENTIONED UPPER LOW WILL HANG AROUND THE STATE THIS
WEEKEND...WITH SATURDAY HAVING A FOUR CORNERS UPPER LOW (INSTEAD OF
THE USUAL 4 CORNERS HIGH). THIS WILL BRING A SOUTHWEST FLOW ALOFT TO
THE AREA...WHICH WILL START A DRYING TRENDS. RIDGE BUILDS IN SUNDAY
AND MONDAY...WHICH WILL WARM UP THE REGION AND ALSO LIMIT AREAL
COVERAGE OF THUNDERSTORMS. THINKS COVERAGE WILL BE ISOLATED EARLY
NEXT WEEK...BUT CHANGED WORDING FROM SCATTERED TO CHANCE DUE TO
UNCERTAINTY.

.TWC...NONE.

AZZ019-029>035-131400-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1206 PM MST TUE AUG 12 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST ARIZONA

.DAY ONE...TODAY

SYNOPSIS...THE THREAT OF SEVERE THUNDERSTORMS PRODUCING DAMAGING
WINDS WILL BE THE MAIN CONCERN TODAY ACROSS THE EASTERN VALLEYS.
THE POTENTIAL FOR PRECIPITATION IN EXCESS OF ONE INCH IS NEAR OR
SLIGHTLY ABOVE CLIMATOLOGY IN THE WESTERN DESERTS.

DISCUSSION...SOUTHEAST ARIZONA WILL EXPERIENCE A LOW GRADE MONSOON
DAY THIS AFTERNOON AND EVENING AS THE COMBINATION OF DRY AIR TO THE
EAST AND WARM MID LEVEL TEMPERATURES PUSHING INTO THE SOUTHEASTERN
PORTION OF THE STATE FROM NEW MEXICO WILL INHIBIT WIDESPREAD
CONVECTION. THE GOES-10 PRECIPITABLE WATER IMAGERY INDICATED THAT A
GRADIENT OF MOISTURE EXISTS FROM WEST TO EAST ACROSS SOUTHEAST
ARIZONA...WITH AS MUCH AS 1.50 INCHES OF PRECIPITABLE WATER SPREAD
ACROSS THE WESTERN DESERTS TO AROUND AN INCH ALONG AND EAST OF A
LINE FROM SAFFORD TO DOUGLAS. THE MORNING UPPER AIR BALLOON SOUNDING
INDICATED WARM TEMPERATURES ALOFT WHICH WILL DELAY CLOUD FORMATION
UNTIL THE AFTERNOON HOURS. STORMS WILL THEN BEGIN TO DEVELOP OVER
THE HIGHER TERRAIN BY MID AFTERNOON WITH SCATTERED THUNDERSTORM
COVERAGE OVER THE MOUNTAINS AND ISOLATED STORM COVERAGE ACROSS THE
VALLEYS.

ALTHOUGH STORM MOTION WILL INITIALLY BE TOWARDS THE WEST AT 5 TO 10
MPH...THEN SHIFT TOWARDS THE SOUTHWEST THIS EVENING.

WITH DIRER LOW LEVEL MOISTURE OUT EAST...THE THREAT OF SEVERE
THUNDERSTORM GENERATED DAMAGING WINDS WILL EXIST...WITH A REDUCED
THREAT FURTHER WEST WHERE DEEPER MOISTURE RESIDES. CONVERSELY...THE
CHANCE FOR PRECIPITATION IN EXCESS OF ONE INCH FALLING IS SLIGHTLY
ABOVE CLIMATOLOGY ACROSS THE WESTERN DESERTS...AND BELOW CLIMATOLOGY
EAST.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

A STRONG IMPULSE WILL SPREAD INTO THE AREA FROM THE EAST THURSDAY
AND THURSDAY NIGHT...WITH A SUBSEQUENT INCREASE IN BOTH THE COVERAGE
OF THUNDERSTORMS AND THE STRENGTH OF SOME STORMS. THE CHANCE FOR
HEAVY RAIN IS EXPECTED TO INCREASE.

.SPOTTER INFORMATION STATEMENT...

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