Severe Thunderstorm Warning 40, NWS Flagstaff, AZ

NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
900 AM MST SAT AUG 12 2000

SYNOPSIS...HIGH PRESSURE WILL REMAIN NEAR THE FOUR CORNERS REGION
INTO THE MIDDLE OF THE COMING WORK WEEK. THIS PATTERN PROMISES
SHOWER AND THUNDERSTORM ACTIVITY EACH DAY ACROSS NORTHERN ARIZONA.

DISCUSSION...LARGE SCALE MID TO UPPER RIDGE REMAINS LOCATED ACROSS
THE SOUTHWEST UNITED STATES WITH THE RIDGE AXIS EXTENDING FROM
SOUTHERN CALIFORNIA INTO OKLAHOMA. EMBEDDED IN THIS GENERAL LARGE
SCALE PATTERN IS AN INVERTED TROUGH CENTERED PRETTY MUCH OVER
ARIZONA. CLOUDINESS/MOISTURE ASSOCIATED WITH THIS FEATURE EXTENDED FROM
NORTHEAST TO SOUTHWEST ACROSS THE CENTRAL PORTION OF THE STATE.
MOISTURE WILL CONTINUE TO MOVE TO THE NORTHWEST TODAY AND PRETTY
MUCH COVER THE ENTIRE CWA BY THIS AFTERNOON. THINK THE CLOUD LAYER
ACROSS THE CENTRAL PART OF THE STATE WILL BURN OFF BY MIDDAY. NOT A
HIGH CAPE DAY BUT GOOD COVERAGE OF HIGH PRECIPITABLE WATER VALUES
(0.75 OR HIGHER) ENSURES WIDESPREAD DEVELOPMENT OF SHOWERS AND
THUNDERSTORMS. THE GENERAL MOTION OF CELLS WILL CONTINUE TO BE TO
THE SOUTHWEST AS THE LOW- TO MID-LEVEL STEERING FLOW IS FROM THE
NORTHEAST.  WITH PRECIPITABLE WATER VALUES SO HIGH ISOLATED BOMBERS
WILL BE POSSIBLE BUT THINK THE POTENTIAL FOR WIDESPREAD HEAVY RAIN
IS MINIMAL. THE INERTIAL STABILITY ALOFT WILL BE QUITE LOW FOR THE
NEXT COUPLE OF DAYS WHICH SUGGEST 24-HOUR A DAY SHOWER AND
THUNDERSTORM ACTIVITY.

MCCOLLUM

.FGZ...NONE

AZZ004>018-037>040-122030-
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
930 AM MST SAT AUG 12 2000

...SCATTERED HEAVY RAIN PRODUCING THUNDERSTORMS OVER NORTHERN
ARIZONA TODAY...

SPOTTER REPORTS OF HAIL...RAINFALL AMOUNTS...AND GUSTY WINDS REQUESTED.

HIGH PRESSURE REMAINS CENTERED OVER THE FOUR CORNERS REGION WITH
AN UPPER DISTURBANCE MOVING ACROSS THE SOUTHERN PORTION OF THE
STATE. AS A RESULT...MOISTURE WILL CONTINUE TO SPREAD ACROSS NORTHERN
ARIZONA TODAY AND THIS WILL LEAD TO SCATTERED SHOWER AND THUNDERSTORM
ACTIVITY OVER MUCH OF THE AREA. THE PRIMARY THREAT TODAY WILL BE
HEAVY RAIN PRODUCING STORMS WHICH WILL BE MOST NUMEROUS ALONG THE
MOGOLLON RIM AND OVER NORTHERN GILA AND YAVAPAI COUNTIES. HEAVY RAIN IS
NOT EXPECTED TO BE WIDESPREAD BUT INDIVIDUAL STORMS WILL BE CAPABLE
OF PRODUCING LOCALIZED FLOODING WITH RAINFALL AMOUNTS OF UP TO 3 INCHES.

THE HAZARDOUS WEATHER OUTLOOK GIVES PRELIMINARY INFORMATION FOR THE
POSSIBILITY OF WEATHER THAT COULD BECOME SEVERE...DAMAGING WINDS IN
EXCESS OF 57 MPH...HAIL 3/4 INCH IN DIAMETER OR LARGER...AND HEAVY
RAINFALL THAT COULD CAUSE FLOODING OR RUNNING WASHES. WHEN
HAZARDOUS WEATHtER BEGINS...IMPORTANT LIFE SAVING INFORMATION WILL BE
PROVIDED IN SHORT TERM FORECASTS...SEVERE WEATHER AND FLOOD WARNINGS
...AND FOLLOW-UP STATEMENTS.

MCCOLLUM