Flash Flood Warning 48, NWS Flagstaff, AZ

NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
230 PM MST SUN AUG 18 2002

.SYNOPSIS...PRECIPITATION CHANCES WILL INCREASE THROUGH THE MIDDLE
OF THE COMING WORK WEEK AS MONSOONAL MOISTURE RETURNS TO THE STATE.
DRIER SOUTHWESTERLY FLOW WILL RETURN THURSDAY...WITH THE FAR WESTERN
ZONES CLEARING...BUT THE EASTERN AND CENTRAL PORTIONS OF THE STATE
WILL REMAIN UNDER A CHANCE OF SHOWERS AND THUNDERSTORMS INTO NEXT
WEEKEND.

.DISCUSSION...ATLANTIC SUBTROPICAL RIDGE WILL NUDGE INTO ARIZONA
OVERNIGHT. OVER THE NEXT THREE DAYS THE SUBTROPICAL RIDGE WILL
REMAIN OVER ARIZONA AS A TROUGH DEVELOPS OVER THE NORTHWEST UNITED
STATES. THIS WILL RESULT IN INCREASING SOUTHERLY FLOW OVER ARIZONA
EXTENDING WELL INTO MEXICO. THE RESULT WILL BE INCREASING MOISTURE
AND THUNDERSTORMS OVER A GOOD PORTION OF THE COUNTY WARNING AREA
(CWA) THE NEXT FEW DAYS. A MID TO UPPER SHORT-WAVE TROUGH AND
ASSOCIATED JET MAX MOVES FROM SOUTH TO NORTH ACROSS ARIZONA FROM
MONDAY INTO TUESDAY ALONG THE NORTHWEST PERIPHERY OF THE SUBTROPICAL
RIDGE. NOT CLEAR WHAT THE EFFECTS OF THE SHORT-WAVE WILL BE BUT WILL
INCREASE COVERAGE OF THUNDERSTORMS. ALSO...WILL NOT INDICATE A
DIURNAL SIGNAL. BY TUESDAY NIGHT THE SHORT-WAVE MOVES NORTH OF THE
STATE WITH COOL AND MORE STABLE AIR BEHIND. HOWEVER...WILL KEEP LOW
POPS IN TUESDAY NIGHT (JUST IN CASE). WEDNESDAY A DISTURBANCE FROM
THE NORTHWEST BRUSHES ARIZONA. THIS WILL BRING INCREASING SHEAR AND
MOISTURE SHOULD SURGE NORTHWARD. THIS SYSTEM ALSO BRINGS COOLER AIR
IN AT ALL LEVELS BUT THE COOLING IS MOST DRAMATIC IN THE LOW LEVELS.
WEDNESDAY HAS THE POTENTIAL TO BE INTERESTING BECAUSE OF THE SHEAR
AND MOISTURE BUT THERE WILL MOST LIKELY BE A CAP OVER THE WESTERN
CWA.

IN THE EXTENDED...THE LATEST RUNS OF THE AVN BRING THE PACIFIC
TROUGH EVEN FURTHER EAST THAN PREVIOUS RUNS. IF THIS HAPPENS COULD
SEE A SHUT DOWN IN THUNDERSTORMS FOR ALL BUT FAR EAST LOCATIONS. FOR
NOW WILL KEEP NORTHWEST PORTION OF THE CWA DRY AND JUST MENTION A
CHANCE OF STORMS OVER THE REMAINDER OF THE AREA. BUT IF FUTURE RUNS
CONTINUE TO SHOW THIS FURTHER EAST TROUGH THE PERIOD FROM THURSDAY
INTO NEXT WEEKEND COULD BE MUCH DRIER AND SOMEWHAT BREEZY.

MCCOLLUM

.FGZ...NONE.

.CODED TEMPERATURES/POPS FOR SELECTED CITIES IN NORTHERN ARIZONA

CITY             TEMPERATURES LO/HI           PROBABILITY OF PRECIP
                 TON MON   TUE     WED        TON MON   TUE     WED
FLAGSTAFF        052/082 053/077 048/074      020 030 030 040 020 030
WINSLOW          063/093 063/089 058/086      020 030 030 030 020 030
PRESCOTT         063/088 063/084 058/081      020 030 030 030 020 020
PAGE             075/097 075/093 070/090      000 000 010 020 020 020
WINDOW ROCK      053/085 053/079 048/076      010 010 020 030 020 040
CANYON DE CHELLY 061/091 061/085 056/082      010 010 020 020 020 030
COTTONWOOD       071/099 071/095 066/092      020 020 020 020 020 020
GRAND CANYON     052/083 053/078 048/075      020 020 020 030 020 020
GREER            049/077 050/072 045/069      020 030 040 050 030 050
HEBER            054/087 055/082 050/079      020 030 040 050 030 040
JACOB LAKE       052/080 053/075 048/072      020 020 020 030 020 020
NAVAJO N.M.      058/085 058/079 053/076      010 010 020 020 020 030
PAYSON           064/092 064/088 059/085      020 020 030 030 020 020
SEDONA           069/096 069/092 064/089      020 020 020 020 020 020
SELIGMAN         056/091 056/087 051/084      010 020 020 020 010 010
SHOW LOW         060/087 061/082 056/079      020 030 030 040 020 040
ST. JOHNS        058/088 058/084 053/081      020 030 030 030 020 030
WUPATKI N.M.     064/095 064/091 059/088      020 030 030 030 020 030

AZZ004>018-037>040-181930-
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
930 AM MST SUN AUG 18 2002

...ISOLATED SHOWERS AND THUNDERSTORMS TODAY AND THIS EVENING
OVER THE EASTERN MOGOLLON RIM AND THE WHITE MOUNTAINS SOUTHWARD...

DISCUSSION...MONSOON MOISTURE WILL BE ON THE INCREASE TODAY OVER
THE MOGOLLON RIM AND WHITE MOUNTAINS AS WELL AS YAVAPAI AND
NORTHERN GILA COUNTIES. THE MAIN THREAT TODAY WILL BE GUSTY WINDS TO
BETWEEN 30 AND 40 MPH IN THE VICINITY OF THUNDERSTORMS.
HOWEVER...OVER THE FAR EASTERN MOGOLLON RIM AND WHITE MOUNTAINS
MOISTURE INCREASES WILL BE ENOUGH FOR A FEW HEAVY RAIN PRODUCING
STORMS.

BURNED AREA RAIN OUTLOOK...
SMALL AMOUNTS OF RAIN CAN CAUSE FLASH FLOODING IN BURNED OUT AREAS.
THE CHANCE OF SIGNIFICANT PRECIPITATION OVER INDIAN BURN SITE
IS VERY LOW TODAY. THE CHANCE OF SIGNIFICANT PRECIPITATION OVER
THE CHEDISKI-RODEO BURN SITE IS MODERATE TODAY.

MCCOLLUM