Severe Thunderstorm Warning 19, NWS Tucson, AZ

SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
204 PM MST SAT JUL 19 2003

.SYNOPSIS...ENOUGH MOISTURE WILL REMAIN IN PLACE TO INTERACT WITH A
WEAK IMPULSE THAT IS FORECAST TO CLIP SOUTHEAST ARIZONA SOMETIME
LATE SUNDAY THROUGH MONDAY. THIS FEATURE IS ANTICIPATED TO BRING AN
UPSWING IN AREAL COVERAGE OF SHOWERS AND THUNDERSTORMS SUNDAY
EVENING THROUGH MONDAY. AS A RESULT...HIGH TEMPERATURES SHOULD BE
SEVERAL DEGREES BELOW NORMAL MONDAY. HOWEVER...HIGHS WILL RECOVERY
QUICKLY WITH SLIGHTLY ABOVE SEASONABLE READINGS RETURNING BY
WEDNESDAY. THE WEATHER PATTERN WILL REMAIN FAVORABLE THROUGH NEXT
WEEK FOR THE TYPICAL SUMMERTIME FORECAST OF POSSIBLE AFTERNOON AND
EVENING THUNDERSTORMS.

.DISCUSSION...SHOWERS AND THUNDERSTORMS WERE HAVING A TUFF TIME
DEVELOPING THIS AFTERNOON DUE TO THE DRIER AND WARMER AIR ALOFT THAT
SPREAD OVER THE AREA FROM OUR EAST THIS MORNING. LATEST RADAR
IMAGERY AT 130 PM MST INDICATED A FEW SHWRS FORMING IN THE MOUNTAINS
OF SE AZ...WITH A RATHER STRONG STORM DEVELOPING EAST OF PHX. THIS
ONE EAST OF PHX WAS EXACTLY WHAT WE NEEDED TO BE CONCERN ABOUT FOR
THIS EVENING. IF A CLUSTER OF MOIST THERMALS MANAGE TO OVERCOME THE
TEMPERATURE INVERSION ALOFT AND DRY AIR ENTRAINMENT...WE COULD BE
LOOKING AT SOME EXPLOSIVE DEVELOPMENT. HOWEVER...STILL THINK
ANYTHING THAT DEVELOPS LATER THIS AFTERNOON AND EVENING WILL BE
ISOLATED IN NATURE. THUS...WILL LOWER POPS MOST LOCATIONS EXCEPT IN
THE MOUNTAINS FOR THE REST OF TODAY AND TONIGHT. ALL MODELS WERE IN
VERY GOOD AGREEMENT WITH SPLITTING OFF A PIECE OF A SHORTWAVE TROUGH
MOVING THROUGH THE CENTRAL ROCKIES AND ROTATING IT AROUND THE
BASE OF THE HIGH CELL. THE ONLY DISCREPANCY BETWEEN THE DIFFERENT
MODELS WAS THE TIMING OF THIS FEATURE. ETA WAS FASTER THAN THE GFS
WHICH WOULD PUT THE HIGHER POPS IN FOR SUNDAY EVENING/NIGHT RATHER
THAN MONDAY AFTERNOON. WILL LEAN MORE TOWARD THE ETA SOLUTION ON THE
AFTERNOON PACKAGE AND CALL FOR AN UPSWING IN AREAL COVERAGE OF
SHWRS/TSTMS SUNDAY EVENING...WITH A FEW LINGERING SHOWERS INTO
MONDAY MORNING. THIS TIMING WOULD THEN SUGGEST SOMEWHAT OF A DELAY
IN REDEVELOPMENT MONDAY AFTERNOON WITH SLIGHTLY LOWER ODDS OF
PRECIP. BEYOND MONDAY...THE HIGH CELL SETTLES OVER THE GREAT BASIN
REGION WITH THE STEERING FLOW REMAINING MORE OR LESS OUT OF THE
NORTHEAST. IN GENERAL...OVERALL LARGE-SCALE PATTERN LOOKS FAVORABLE
FOR MAINTAINING THE MOISTURE SUPPLY FOR STANDARD SUMMERTIME TSTM
FORECAST. HIGH TEMPERATURES WILL LIKELY DROP A FEW DEGREES MOST
PLACES MONDAY WITH THE ANTICIPATED PRECIP SUNDAY NIGHT AND MONDAY
MORNING. HOWEVER...READINGS WILL RECOVER NICELY BY WEDNESDAY TO
SLIGHTLY ABOVE NORMAL.

.TWC...NONE.

AZZ019-029>035-201400-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1220 PM MST SAT JUL 19 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST ARIZONA

.DAY ONE...TODAY

SYNOPSIS...ABUNDANT MOISTURE ACROSS PORTIONS OF THE COUNTY WARNING
AREA RESULTS IN CONCERN FOR HEAVY PRECIPITATION. HOWEVER...DRIER
UPPER LEVEL AIR MOVING INTO EASTERN PORTIONS OF ARIZONA MAY BE A
LIMITING FACTOR.  ALTHOUGH THREAT OF SEVERE WEATHER WILL REMAIN VERY
LOW...BEST CHANCES MAY BE IN WESTERN PORTIONS OF THE COUNTY WARNING
AREA.

DISCUSSION...DECENT MOISTURE PROFILE IN THE 12Z KTUS SOUNDING WITH
PRECIPITABLE WATER VALUES OF 1.5 INCHES.  GOES TOTAL PRECIPITATION
ALSO SHOWS THE DEEPER MOISTURE FROM TUCSON WESTWARD. ALTHOUGH
ABUNDANT MOISTURE WOULD CREATE MAIN CONCERN FOR HEAVY
PRECIPITATION...DRIER UPPER LEVEL AIR CONTINUE TO PUSH INTO EASTERN
PORTIONS OF ARIZONA THIS MORNING.  DRYING IS EVIDENT IN THE GOES
TOTAL PRECIPITABLE WATER WITH VALUES DROPPING TO LESS THAN ONE
INCH.  THIS DRYING MAY LIMIT ANY THUNDERSTORM DEVELOPMENT FOR
EASTERN PORTIONS OF THE CWA. EVEN VISIBLE IMAGERY IS NOT INDICATING
ANY DECENT VERTICAL NATURE TO THE CU FIELD ACROSS THE CWA.
HOWEVER...ISOLATED THUNDERSTORMS HAVE BEEN ABLE TO GENERATE NORTH OF
NORTHERN GREENLEE COUNTY ALONG THE RIM.  WITH SOME REASONABLE
INSTABILITY SHOWN IN 12Z FLG SOUNDING...THUNDERSTORMS SHOULD BE ABLE
TO DEVELOP LATER IN THE AFTERNOON ALONG THE WHITE MOUNTAINS. A FEW
STRONGER STORMS MAY PRODUCE BRIEF HEAVY RAIN. HOWEVER...THIS WILL
NOT BE A MAIN THREAT DUE TO THE UPPER LEVEL DRYING.  THE BEST
MOISTURE VIA GOES PW APPEARS TO BE FROM TUCSON WEST.  EVIDENCE OF A
WEAK CIRCULATION PROMPTED SOME DEVELOPMENT IN CENTRAL PIMA COUNTY
THIS MORNING. HOWEVER...RADAR ECHOES WERE EXTREMELY WEAK.  ALTHOUGH
A LOWER THAN A TYPICAL MONSOON DAY CAN BE EXPECTED...THE BEST SEVERE
THREAT AND PRECIPITATION GREATER THAN ONE INCH TODAY WILL BE LOCATED
FROM CENTRAL PIMA COUNTY EASTWARD THROUGH EASTERN PORTIONS OF
COCHISE AND GRAHAM COUNTIES.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

SUFFICIENT MOISTURE WILL BE IN PLACE FOR A STANDARD SUMMERTIME
THUNDERSTORM SEASON FORECAST. EXPECT SCATTERED MAINLY AFTERNOON AND
EVENING SHOWERS AND THUNDERSTORMS.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.