Damaging Wind in Arizona, July 28, 2001

SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
230 PM MST SAT JUL 28 2001

SYNOPSIS...MOISTURE WILL BE ON A GRADUAL INCREASE THROUGH THE
WEEKEND AS HIGH PRESSURE BUILDS FROM NORTHERN ARIZONA INTO THE
CENTRAL PLAINS. EXPECT SCATTERED AFTERNOON AND EVENING THUNDERSTORMS
THROUGH THE UPCOMING WEEK.

DISCUSSION...HIGH PRESSURE REORGANIZING WITH ILL DEFINED CENTER
BUILDING IN NORTHEAST ARIZONA TODAY. WEAK EASTERLY IMPULSE NEAR
SONORA COULD FOCUS ANOTHER COMPLEX NEAR THE BORDER OVERNIGHT. NEW
HIGH CIRCULATION WRAPPING SLIGHTLY COOLER MID LEVEL AIR INTO THE
AREA FROM TRAILING REMAINS OF TROUGH. PRECIPITABLE WATER VALUES
STILL IN THE 1.2 TO 1.5 INCH RANGE ACROSS OUR AREA...BUT NOT MUCH
FOR THE NORTHERN HALF OF THE STATE. WIND PROFILE STARTING TO SHOW
FAVORABLE VECTORS FOR A LITTLE BETTER ORGANIZATION...AND CONVECTION
SO FAR THIS AFTERNOON HAS BORNE THIS OUT. SHOULD CONTINUE TO BE A
GOOD AFTERNOON FOR MOUNTAIN STORMS WITH ENOUGH SUPPORT FOR MORE
VALLEY STORMS THAN YESTERDAY.

INCREASING EASTERLY FLOW AND APPARENT ONGOING SURGE TRYING TO EXTEND
DEEPER MOISTURE WESTWARD. SHOULD SEE FLOW BECOME SOUTHEASTERLY AND
THEN SOUTHERLY IN RESPONSE TO THE RIDGE SHIFTING EASTWARD AND
DEVELOPMENT OF ANOTHER WEST COAST TROUGH. M

.TWC...NONE.

AZZ019-029>035-290700-

SOUTHEAST ARIZONA HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1135 AM MST SAT JUL 28 2001

.SYNOPSIS...THE FOCUS FOR THUNDERSTORM ACTIVITY TODAY WILL BE ACROSS
THE EASTERN PORTIONS OF STATE AS THE MIXTURE OF AMPLE SURFACE
HEATING...INCREASED MID LEVEL MOISTURE AND A DESTABILIZING ATMOSPHERE
ALOFT WILL AID THUNDERSTORM DEVELOPMENT. EAST OF TUCSON...THERE IS AN
INCREASED THREAT OF SEVERE DOWNBURST WINDS IN THE VALLEYS WITH A NEAR
CLIMATOLOGICAL THREAT OF FLASH FLOODING.

.DISCUSSION...THE MAJORITY OF THE THUNDERSTORM ACTIVITY TODAY WILL
OCCUR OVER THE HIGHER TERRAIN ACROSS THE EASTERN PORTIONS OF THE COUNTY
WARNING AREA. FIRST OF ALL...UPPER LEVEL NORTHEAST WINDS WILL TRANSPORT
COLDER AIR ALOFT WHICH WILL DESTABILIZE THE ATMOSPHERE ACROSS THE
REGION. IN ADDITION...AN EASTERLY FLOW AT MID LEVELS WILL TRANSPORT
MOISTURE BACK INTO THE EASTERN COUNTIES. COMBINE THESE FACTORS WITH
PLENTY OF SUNSHINE TODAY AND YOU HAVE NO PROBLEM DEVELOPING
THUNDERSTORMS OVER THE MOUNTAINS. SINCE THE STEERING FLOW IS NORTHEAST
AT 15 MPH...STORMS WILL BE ABLE TO PUSH OFF OF THE MOUNTAINS LATE THIS
AFTERNOON AND ORGANIZE OVER THE VALLEYS. HOWEVER...THE SPEED OF THE
STORMS AND THE FACT THAT DRIER AIR OCCUPIES THE LOWER LEVELS WILL
DECREASE THE THREAT OF HEAVY RAIN AND THUS THE THREAT OF FLASH
FLOODING. IT WILL HOWEVER INCREASE THE THREAT OF SEVERE STORMS WITH
STRONG WINDS BEING THE SIGNIFICANT PLAYER.

STORM MOVEMENT WILL BE TO THE SOUTHWEST AT 15 MPH.