Damaging Wind in Arizona, July 6, 2001

NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
230 PM MST FRI JUL 06 2001

SYNOPSIS...SOUTHERLY FLOW WILL CONTINUE TO BRING MOISTURE NORTHWARD
ACROSS NORTHERN ARIZONA. AS A RESULT...EXPECT DAILY SHOWERS AND
THUNDERSTORMS OVER MUCH OF THE AREA INTO NEXT WEEK.

DISCUSSION...WEAK UPPER TROUGH NEAR BAJA CALIFORNIA CONTINUES TO
APPROACH NORTHERN ARIZONA WITH AN UPPER RIDGE CENTERED OVER THE
OKLAHOMA PANHANDLE. THE PRESSURE GRADIENT BETWEEN THESE SYSTEMS WILL
RESULT IN A MID-LEVEL SOUTHERLY FLOW FOR AT LEAST THE NEXT COUPLE OF
DAYS WITH A MOIST LOW TO MID LEVEL AIR MASS ADVECTING NORTHWARD INTO
NORTHERN ARIZONA. ON SATURDAY...THE AVN IS PROMISING SOME
STABILIZATION AS THE MID LEVELS DRY A LITTLE AND A MOIST BUT COOL
BOUNDARY LAYER REMAINS BEHIND THE TROUGH. HOWEVER...WILL GO WITH A
GENERAL CHANCE POPS GIVEN THE RATHER HIGH AMOUNTS OF BOUNDARY LAYER
MOISTURE ACROSS THE SOUTHWEST UNITED STATES (ONLY EXCEPTION WILL BE
SLIGHT CHANCE POPS FOR LOCATIONS SOUTH OF THE MOGOLLON RIM). THIS
MOISTURE SHOULD BE TOUGH TO SCOUR OUT. ON SUNDAY THE MOIST SOUTHERLY
FLOW WILL CONTINUE. WILL NOT INDICATE A DIURNAL TENDENCY IN CONVECTION
SINCE WITH MOIST SOUTHERLY FLOW THUNDERSTORMS CAN DEVELOP ALMOST ANY
TIME OF DAY. PRECIPITABLE WATER VALUES WILL REMAIN FAIRLY HIGH SO
EXPECT A THREAT OF LOCALIZED FLASH FLOODING THE NEXT TWO DAYS.
SLIGHTLY LOWER DAYTIME HIGHS ON SATURDAY AS THE COOL TROUGH CORE
MOVES OVER ARIZONA AND THEN SOME WARMING ON SUNDAY AS THE UPPER
RIDGE REBUILDS. WINDS WILL GENERALLY REMAIN LIGHT AND VARIABLE
EXCEPT IS ASSOCIATION WITH THUNDERSTORMS.

IN THE EXTENDED...SUBTROPICAL RIDGE REMAINS NEARLY STATIONARY OVER
REMAINING CENTERED NEAR COLORADO INTO NEXT WEEK. THIS WILL RESULT IN
THE CONTINUATION OF MOIST SOUTHERLY FLOW AND THE CHANCE OF SHOWERS
AND THUNDERSTORMS EACH DAY.

MCCOLLUM

.FGZ...NONE.