Severe Thunderstorm Warning 7, NWS Tucson, AZ

SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
200 PM MST SUN JUL 1 2001

SYNOPSIS...HIGH PRESSURE ALOFT WILL REMAIN OVER THE GREAT BASIN
THIS WEEK...ALLOWING A MOIST EAST FLOW TO STRENGTHEN OVER SOUTHEAST
ARIZONA. THUNDERSTORM ACTIVITY WILL INCREASE IN AREAL COVERAGE AND
SPREAD WESTWARD DURING THE WEEK.

DISCUSSION...SURFACE DEWPOINTS ARE NOTICEABLY HIGHER THAN 24 HOURS
AGO...EVEN IN LOCATIONS NOT HIT BY OUTFLOW BOUNDARIES YET. 850 MB
AND 700 MB DEWPOINT/THETA E PROGS SUGGEST AN ACTIVE EVENING...WHICH
CURRENT DOPPLER IMAGERY SUPPORTS. HAVE BUMPED UP POPS THROUGHOUT THE
SHORT TERM FORECAST PERIOD. WILL CONTINUE TO SEE THE THREAT OF
BLOWING DUST/DOWNBURST WINDS THE NEXT 24 HOURS.

WILL HAVE TO WATCH FOR A POSSIBLE GULF SURGE AND/OR MCS NEAR THE
INTERNATIONAL BORDER TONIGHT/MONDAY. A STRONG INCREASE IN LOW LEVEL
MOISTURE DURING THE NEXT 24 HOURS WOULD BRING THE FIRST MONSOON DAY
TO SOUTHEAST ARIZONA ON MONDAY OR TUESDAY. STARTING MONDAY NIGHT IN
MOST LOCATIONS...THE THREAT EMPHASIS WILL SHIFT TOWARD FLASH
FLOODING.

PIECES OF A RETROGRADING UPPER LEVEL TROUGH WILL WORK INTO SOUTHERN
ARIZONA/NORTHWEST MEXICO LATER THIS WEEK. THIS TROUGH WILL BRING
EVEN MORE LOW LEVEL MOISTURE INTO THE STATE. MAY SEE NOCTURNAL
STORMS DUE TO THE SYNOPTIC SCALE FORCING WITH THIS SYSTEM. BOTTOM
LINE IS EXPECT AN ACTIVE WEEK.

OKULSKI

.TWC...NONE.

AZZ019-029>035-020700-

SOUTHEAST ARIZONA HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1145 AM MST SUN JUL 1 2001

.SYNOPSIS...THERE HAS BEEN A SIGNIFICANT INCREASE IN MOISTURE ACROSS
SOUTHEAST ARIZONA WITH THE MONSOON BOUNDARY AS FAR NORTH AS TUCSON
ON THE 12Z DATA. THIS WILL LEAD TO AN INCREASE IN AREAL COVERAGE AND
INTENSITY OF STORMS THIS AFTERNOON AND TONIGHT.

.DISCUSSION...TUCSON SOUNDING AND ANALYSIS OF DATA INDICATES MONSOON
MOISTURE HAS MOVED INTO THE SOUTHEAST PORTION OF THE STATE WITH 850
DEW POINT VALUES NEAR 8C AT TUS THIS MORNING. SIGNIFICANT MID LEVEL
MOISTURE HAS ALSO MOVED INTO AREA ABOVE 600 MB. MOIST ADIABAT DOWN
TO 850 LEVEL WOULD GIVE US A DEW POINT OF 12C! ALSO TO NOTE THAT ALL
THE WINDS UP TO 10000 FEET ARE LIGHT SO THAT MIXING OF DRY AIR TO
OFFSET MOISTURE IS NO LONGER OCCURRING. ONE OF THE NEXT FEW DAYS
WILL PROBABLY SEE OUR FIRST MONSOON DAY OF THE SEASON.

LAST NIGHTS CONVECTION LEAVES A BOUNDARY ALONG THE MEXICAN BORDER
WHICH SHOULD FOCUS STORMS IN THAT AREA. ALOFT...DYNAMICS DONT LOOK
ALL THAT GREAT TODAY (TOMORROW THINGS LOOK GREAT) BUT THE FOCUS OF
THE HEAVIER STORMS WILL BE SOUTH OF AN EAST WEST LINE FROM ABOUT
30 MILES NORTH OF THE MEXICAN BORDER FROM DOUGLAS...SIERRA VISTA AND
NOGALES WITH A MODERATE RISK OF FLASH FLOODING IN THOSE AREAS. THE
TUCSON AREA WILL BE LOW RISK. THE SEVERE POTENTIAL WILL ONCE AGAIN
BE HIGHER NEAR THE HEAVIEST STORMS...BUT THE INVERTED V SOUNDINGS
WILL INCREASE THE THREAT TO THE TUCSON...WILLCOX AREAS.

STORM MOTION WILL BE TOWARDS THE WEST AT 10 TO 15 MPH.

GRAPHICS WILL BE DELAYED UNTIL ABOUT 2 PM.