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000
FXUS65 KTWC 210946
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
245 AM MST THU AUG 21 2014

.SYNOPSIS...AN UPPER LOW OVER SOUTHERN CALIFORNIA THIS MORNING WILL
WEAKEN TODAY AS IT MOVES ACROSS ARIZONA THROUGH EARLY FRIDAY. EXPECT
SCATTERED SHOWERS AND THUNDERSTORMS INTO THIS EVENING BEFORE
ACTIVITY ENDS FROM WEST TO EAST OVERNIGHT. DRIER AIR BEHIND THE LOW
WILL LIMIT THUNDERSTORMS TO MAINLY EAST AND SOUTH OF TUCSON FRIDAY
AND THROUGH THE WEEKEND. AFTER A COUPLE OF COOLER THAN NORMAL DAYS
HIGH TEMPERATURES WILL WARM BACK UP TO NORMAL OVER THE WEEKEND.

&&

.DISCUSSION...CLOSED UPPER LOW OFF SRN CALIFORNIA COAST THIS MORNING
HAS TAPPED INTO SOME MID TO HIGH LEVEL MOISTURE FROM THE OUTER EDGES
OF TROPICAL STORM LOWELL AND SPREAD IT NORTH ACROSS WESTERN ARIZONA.
THE YUMA DOPPLER RADAR AT 230 AM SHOWED A FEW LIGHT SHOWERS OVER THE
NORTHERN GULF OF CALIFORNIA...NEAR ROCKY POINT AND SOUTH OF
LUKEVILLE. PRECIPITABLE WATER VALUES THIS MORNING WERE AROUND 1.30"
AREAWIDE WITH MODELS SUGGESTING THAT THESE VALUES WILL RISE INTO
1.50"-1.60" RANGE THIS AFTERNOON. THIS CLOSED UPPER LOW WILL SLOWLY
DIG S THIS MORNING BEFORE MAKING THE TURN EAST INTO NORTHERN BAJA
CALIFORNIA. EXPECT SCATTERED SHOWERS TO DEVELOP WEST OF TUCSON THIS
MORNING AND SLOWLY SPREAD/DEVELOP ACROSS THE REMAINDER OF THE
FORECAST AREA THIS AFTERNOON INTO THIS EVENING. NOT GOING OVERLY
WILD ON QPF VALUES...MOSTLY LESS THAN A QUARTER OF AN INCH...BUT
COULD SEE SOME LOCALIZED 1" RAIN AMOUNTS WHERE STORMS GET SOME MORE
SUN. CAN`T RULE OUT THAT A STORM OR TWO WILL GETTING PRETTY STRONG
EITHER WITH WIND GUSTS UP TO 50 MPH. WITH THE CLOUD COVER AND
SHOWERS...HIGH TODAY WILL REMAIN BELOW NORMAL WITH SOME LOCALS
RUNNING 7-10 DEGREES BELOW NORMAL...ESPECIALLY OUT WEST. OVERALL
THIS IS NOT YOUR TYPICAL AUGUST MONSOON DAY.

THIS CLOSED LOW OPENS UP THIS EVENING AS IT MOVES INTO SW AZ AND
CONTINUES TO LIFT NE ACROSS THE STATE OVERNIGHT INTO FRIDAY MORNING.
SCATTERED STORMS CONTINUING ACROSS MOST OF THE AREA THIS EVENING
BEFORE DRIER AIR PUNCHES INTO WESTERN AREAS AND MOVES ACROSS THE
AREA OVERNIGHT. THUS EXPECT STORMS TO END FROM WEST TO EAST.

UPPER TROF AXIS OVER THE EASTERN AREAS FRIDAY AFTERNOON. ALTHOUGH PW
VALUES WILL BE DOWN VERSUS TODAY...STILL WILL SEE ISOLATED TO
SCATTERED STORMS FRIDAY AFTERNOON. HIGHS WARMER THAN TODAY BUT STILL
BELOW NORMAL.

LOW GRADE MONSOON FORECAST FOR THE WEEKEND AS AN UPPER TROF PASSING
BY TO THE NORTH KEEPS DRIER WESTERLY FLOW OVER THE AREA. HOWEVER
WILL HAVE ENOUGH RESIDUAL MOISTURE FOR SLIGHT CHANCE OF STORMS
MAINLY SOUTH AND EAST OF TUCSON. WARMER WITH HIGHS SLIGHTLY ABOVE
NORMAL BOTH DAYS.

NEXT WEEK...WITH UNCERTAINTY ON AMOUNT OF TROPICAL MOISTURE BEING
SENT OUR WAY FROM THE NEXT PACIFIC TROPICAL STORM...WENT WITH BASIC
CLIMO POPS AREAWIDE. MODELS ARE SUGGESTING THAT WE COULD SEE LIGHT
SOUTHERLY WINDS MOVING UP THE GULF OF CALIFORNIA AS EARLY AS SUNDAY
WITH STRONGER WINDS ON MONDAY WHICH WILL BRING GULF SURGE LIKELY
MONDAY NIGHT INTO TUESDAY. HIGHS WILL REMAIN SLIGHTLY ABOVE NORMAL.

&&

.AVIATION...VALID THRU 22/12Z.
BKN-OVC CLOUDS MAINLY ABOVE 12K FT AGL THRU 21/15Z...THEN SCT-BKN
CLOUDS AT 6-10K FT AGL AND BKN-OVC CLOUDS AOA 12K FT AGL. ISOLD-SCT
SHOWERS AND THUNDERSTORMS DEVELOPING DURING THE MID MORNING HOURS
AND PERSISTING THRU TONIGHT. PRECIPITATION CHANCES WILL BE HIGHEST
WEST OF A KOLS TO KTUS TO KCGZ LINE THIS MORNING THRU THE MID
AFTERNOON HOURS...AND THEN EAST OF THIS LINE LATE THIS AFTERNOON AND
TONIGHT. MVFR VISIBILITIES AND WIND GUSTS TO 45 KTS WILL BE POSSIBLE
WITH THE STRONGER TSRA. OUTSIDE OF THUNDERSTORM OUTFLOWS...SURFACE
WIND WILL GENERALLY BE LESS THAN 10 KTS. AVIATION DISCUSSION NOT
UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE
EXPECTED THROUGH EARLY NEXT WEEK. THE STRONGER THUNDERSTORMS WILL
PRODUCE STRONG...GUSTY AND ERRATIC WINDS. OUTSIDE OF THUNDERSTORM
OUTFLOWS...20-FOOT WINDS WILL EXHIBIT NORMAL DIURNAL TRENDS AND WILL
BE MOSTLY LESS THAN 15 MPH.

&&

$$

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000
FXUS65 KTWC 210406 CCA
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
906 PM MST WED AUG 20 2014

.SYNOPSIS...AN UPPER LOW OVER SOUTHERN CALIFORNIA WILL MOVE ACROSS
NORTHERN ARIZONA LATE THURSDAY NIGHT AND EARLY FRIDAY WITH SCATTERED
SHOWERS AND THUNDERSTORMS EXPECTED THURSDAY AFTERNOON AND NIGHT.
DRIER AIR BEHIND THE LOW WILL LIMIT CONVECTION TO MAINLY EASTERN AND
SOUTHERN AREAS FRIDAY THROUGH THE WEEKEND.  AFTER A COUPLE OF COOLER
THAN NORMAL DAYS...HIGH TEMPERATURES WILL WARM BACK UP TO NORMAL
OVER THE WEEKEND.

&&

.DISCUSSION...IT WAS A RELATIVELY DOWN DAY FOR CONVECTION ACROSS
SOUTHEAST ARIZONA AS SHOWERS AND THUNDERSTORMS GENERALLY STRUGGLED
AWAY FROM HIGHER TERRAIN AREAS. THE ONE EXCEPTION WAS EARLIER THIS
EVENING ACROSS CENTRAL AND WESTERN PIMA COUNTY WHERE A FEW SPOTS HAD
ONE TO TWO INCHES OF RAINFALL. THESE SHOWERS AND STORMS HAVE JUST
ABOUT DISSIPATED THOUGH BASED ON LATEST RADAR IMAGERY.
MEANWHILE...MOSTLY CLOUDY SKIES PREVAIL FOR AREAS FROM TUCSON
WESTWARD...WITH MOSTLY CLEAR TO PARTLY CLOUDY SKIES EAST OF TUCSON.

THERE IS A CONSIDERABLE AMOUNT OF MID/UPPER LEVEL MOISTURE THAT IS
STREAMING TO THE NORTHEAST FROM THE BAJA REGION...MOST OF WHICH IS
ATTRIBUTED TO TROPICAL STORM LOWELL. THE OTHER MAJOR FEATURE IS AN
ANOMALOUS UPPER LEVEL LOW THAT IS ALONG THE SOUTHERN CALIFORNIA
COAST AT THIS TIME. THE BIG QUESTION HEADING INTO THURSDAY WILL BE
HOW MUCH CLOUD COVERAGE WILL LIMIT INSTABILITY AND THUS CONVECTION
AS THERE WILL CERTAINLY BE FAVORABLE DYNAMICS EAST OF THE UPPER LOW
TO WORK WITH DURING THE DAY THURSDAY. MADE SOME MINOR TWEAKS TO THE
GRIDS BY INCREASING POPS AND SKY COVERAGE ACROSS THE CENTRAL AND
WESTERN DESERTS THROUGH THURSDAY MORNING AS SOME SHOWERS ARE
POSSIBLE WITH ANY EMBEDDED DISTURBANCES IN THE MID/UPPER LEVEL
MOISTURE PLUME. SEE PREVIOUS FORECAST DISCUSSION BELOW FOR
ADDITIONAL INFORMATION.

&&

.AVIATION...VALID THRU 21/00Z.
BKN-OVC SKIES ABOVE 10K FT AGL MAINLY FROM KTUS WESTWARD INTO
THURSDAY MORNING WITH SCT-BKN CLOUDS EAST OF KTUS. CHC OF -SHRA
ACTIVITY WILL GENERALLY BE LOW DURING THE OVERNIGHT HOURS WITH THE
BEST CHANCES WEST OF KTUS. AFTER 22/18Z SCT SHRA/TSRA ARE EXPECTED
TO DEVELOP ACROSS SOUTHEAST ARIZONA...BUT CONFIDENCE TOO LOW ON
TIMING AND LOCATION TO INCLUDE IN ANY TAF SITES. WINDS WILL
GENERALLY REMAIN LIGHT AND LESS THAN 10 KTS...THOUGH THUNDERSTORMS
THURSDAY WOULD RESULT IN GUSTY AND ERRATIC WINDS.

&&

.FIRE WEATHER...ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS ARE EXPECTED THROUGH EARLY NEXT WEEK. HOWEVER...THE
OVERALL TREND IN THUNDERSTORM ACTIVITY WILL BE DIMINISHED FROM
RECENT WEEKS. THE STRONGER THUNDERSTORMS WILL STILL PRODUCE
STRONG...GUSTY AND ERRATIC WINDS. OUTSIDE OF THE THUNDERSTORM
OUTFLOWS...20-FOOT WINDS WILL EXHIBIT NORMAL DIURNAL TRENDS AND WILL
BE MOSTLY LESS THAN 15 MPH. ALSO...RELATIVE HUMIDITY VALUES WILL
FALL A BIT LOWER THAN RECENT WEEKS DUE TO SOME DRYING IN THE
ATMOSPHERE...BUT WE WILL REMAIN ABOVE CRITIC RELATIVE HUMIDITY
THRESHOLDS THROUGH EARLY NEXT WEEK.

&&

.PREV DISCUSSION...SOMEWHAT INTERESTING WEATHER THE NEXT 36 HOURS AS
THE UPPER LOW MOVING OVER SOUTHERN CALIFORNIA OPENS UP AND MOVES
NORTHEAST ACROSS CENTRAL/NORTHERN ARIZONA LATER THURSDAY NIGHT INTO
FRIDAY MORNING.  WATER VAPOR LOOP SHOWING HIGH LEVEL MOISTURE FROM
TS LOWELL BEGINNING TO MOVE NORTH OVER SOUTHERN AZ WITH THE MID
LEVEL MOISTURE EXPECTED LATE TONIGHT INTO THURSDAY WHICH WILL
MOISTEN UP THE ATMOSPHERE SOME.  WHILE THE TIMING OF THE SYSTEM IS
NOT IDEAL (A BIT LATE) IT SHOULD BE GOOD ENOUGH TO HELP FIRE OFF
CONVECTION THURSDAY AFTERNOON INTO THURSDAY NIGHT WITH SOMEWHAT OF A
FOCUS OVER CENTRAL/WESTERN PIMA COUNTY.  VARIETY OF HI RES MODELS
INDICATE PLENTY OF MID AND HIGH LEVEL CLOUDS AROUND WITH SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS.  I HAVE TWEAKED POPS UP SOME
FROM WHAT WE HAD...ESPECIALLY WEST FOR THE AFTERNOON AND EVENING
HOURS.  AS A RESULT OF THE ANTICIPATED INCREASE IN CLOUDS AND
SHOWERS WE WILL HAVE ANOTHER COOLER THAN NORMAL DAY.

FOR FRIDAY...THE UPPER LOW...ACTUALLY AN OPEN TROUGH BY THIS POINT
WILL MOVE NE OF THE AREA WITH SOMEWHAT DRIER AIR MOVING OVER THE
REGION AT THE MID AND HIGH LEVELS WITH THE EXCEPTION OF ALONG THE
ITRNL BORDER WHICH WILL DIMINISH THE SHOWER AND THUNDERSTORM THREAT
AREAS FROM TUCSON NORTH AND WEST.  ANOTHER COOLER THAN NORMAL DAY
THANKS TO A BOTTOMING OUT OF HEIGHTS AND THICKNESS WITH THE PASSING
TROUGH.

FOR THE WEEKEND THROUGH MONDAY THERE WILL BE WESTERLY FLOW ACROSS
THE REGION LIMITING THE ATMOSPHERIC MOISTURE TO SLIGHTLY BELOW
NORMAL LEVELS.  STILL ENOUGH FOR ISOLATED TO SCATTERED CONVECTION
BUT PRIMARILY OVER SOUTH AND EAST OF TUCSON.  WITH FEWER CLOUDS AND
REBOUNDING THICKNESS VALUES HIGH TEMPERATURES ARE EXPECTED TO
REBOUND TO NORMAL LEVELS.

FOR THE MIDDLE OF NEXT WEEK SOME QUESTIONS ARISE DUE TO A POTENTIAL
TROPICAL SYSTEM OVER THE EASTERN PACIFIC.  THE QUESTION RELATES TO
HOW MUCH MOISTURE MAY BE TOSSED OUR WAY AND WHEN AS THE SYSTEM HEADS
OUT TO SEA.  IF LITTLE TO NONE OF THIS TROPICAL MOISTURE MAKES IT
THIS FAR NORTH WE WILL CONTINUE TO HAVE LESS THAN NORMAL CONVECTION
ACROSS THE AREA.  IF IT MANAGES TO MAKE IT HERE IT WILL BE MORE
ACTIVE.  WITHOUT A CLEAR SIGNAL AT THIS TIME I HAVE LEFT THE
FORECAST AS IS WHICH IS A LOW GRADE MONSOON FORECAST WITH NEAR
NORMAL TEMPERATURES.  CERNIGLIA

&&

$$

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000
FXUS65 KTWC 210406 CCA
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
906 PM MST WED AUG 20 2014

.SYNOPSIS...AN UPPER LOW OVER SOUTHERN CALIFORNIA WILL MOVE ACROSS
NORTHERN ARIZONA LATE THURSDAY NIGHT AND EARLY FRIDAY WITH SCATTERED
SHOWERS AND THUNDERSTORMS EXPECTED THURSDAY AFTERNOON AND NIGHT.
DRIER AIR BEHIND THE LOW WILL LIMIT CONVECTION TO MAINLY EASTERN AND
SOUTHERN AREAS FRIDAY THROUGH THE WEEKEND.  AFTER A COUPLE OF COOLER
THAN NORMAL DAYS...HIGH TEMPERATURES WILL WARM BACK UP TO NORMAL
OVER THE WEEKEND.

&&

.DISCUSSION...IT WAS A RELATIVELY DOWN DAY FOR CONVECTION ACROSS
SOUTHEAST ARIZONA AS SHOWERS AND THUNDERSTORMS GENERALLY STRUGGLED
AWAY FROM HIGHER TERRAIN AREAS. THE ONE EXCEPTION WAS EARLIER THIS
EVENING ACROSS CENTRAL AND WESTERN PIMA COUNTY WHERE A FEW SPOTS HAD
ONE TO TWO INCHES OF RAINFALL. THESE SHOWERS AND STORMS HAVE JUST
ABOUT DISSIPATED THOUGH BASED ON LATEST RADAR IMAGERY.
MEANWHILE...MOSTLY CLOUDY SKIES PREVAIL FOR AREAS FROM TUCSON
WESTWARD...WITH MOSTLY CLEAR TO PARTLY CLOUDY SKIES EAST OF TUCSON.

THERE IS A CONSIDERABLE AMOUNT OF MID/UPPER LEVEL MOISTURE THAT IS
STREAMING TO THE NORTHEAST FROM THE BAJA REGION...MOST OF WHICH IS
ATTRIBUTED TO TROPICAL STORM LOWELL. THE OTHER MAJOR FEATURE IS AN
ANOMALOUS UPPER LEVEL LOW THAT IS ALONG THE SOUTHERN CALIFORNIA
COAST AT THIS TIME. THE BIG QUESTION HEADING INTO THURSDAY WILL BE
HOW MUCH CLOUD COVERAGE WILL LIMIT INSTABILITY AND THUS CONVECTION
AS THERE WILL CERTAINLY BE FAVORABLE DYNAMICS EAST OF THE UPPER LOW
TO WORK WITH DURING THE DAY THURSDAY. MADE SOME MINOR TWEAKS TO THE
GRIDS BY INCREASING POPS AND SKY COVERAGE ACROSS THE CENTRAL AND
WESTERN DESERTS THROUGH THURSDAY MORNING AS SOME SHOWERS ARE
POSSIBLE WITH ANY EMBEDDED DISTURBANCES IN THE MID/UPPER LEVEL
MOISTURE PLUME. SEE PREVIOUS FORECAST DISCUSSION BELOW FOR
ADDITIONAL INFORMATION.

&&

.AVIATION...VALID THRU 21/00Z.
BKN-OVC SKIES ABOVE 10K FT AGL MAINLY FROM KTUS WESTWARD INTO
THURSDAY MORNING WITH SCT-BKN CLOUDS EAST OF KTUS. CHC OF -SHRA
ACTIVITY WILL GENERALLY BE LOW DURING THE OVERNIGHT HOURS WITH THE
BEST CHANCES WEST OF KTUS. AFTER 22/18Z SCT SHRA/TSRA ARE EXPECTED
TO DEVELOP ACROSS SOUTHEAST ARIZONA...BUT CONFIDENCE TOO LOW ON
TIMING AND LOCATION TO INCLUDE IN ANY TAF SITES. WINDS WILL
GENERALLY REMAIN LIGHT AND LESS THAN 10 KTS...THOUGH THUNDERSTORMS
THURSDAY WOULD RESULT IN GUSTY AND ERRATIC WINDS.

&&

.FIRE WEATHER...ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS ARE EXPECTED THROUGH EARLY NEXT WEEK. HOWEVER...THE
OVERALL TREND IN THUNDERSTORM ACTIVITY WILL BE DIMINISHED FROM
RECENT WEEKS. THE STRONGER THUNDERSTORMS WILL STILL PRODUCE
STRONG...GUSTY AND ERRATIC WINDS. OUTSIDE OF THE THUNDERSTORM
OUTFLOWS...20-FOOT WINDS WILL EXHIBIT NORMAL DIURNAL TRENDS AND WILL
BE MOSTLY LESS THAN 15 MPH. ALSO...RELATIVE HUMIDITY VALUES WILL
FALL A BIT LOWER THAN RECENT WEEKS DUE TO SOME DRYING IN THE
ATMOSPHERE...BUT WE WILL REMAIN ABOVE CRITIC RELATIVE HUMIDITY
THRESHOLDS THROUGH EARLY NEXT WEEK.

&&

.PREV DISCUSSION...SOMEWHAT INTERESTING WEATHER THE NEXT 36 HOURS AS
THE UPPER LOW MOVING OVER SOUTHERN CALIFORNIA OPENS UP AND MOVES
NORTHEAST ACROSS CENTRAL/NORTHERN ARIZONA LATER THURSDAY NIGHT INTO
FRIDAY MORNING.  WATER VAPOR LOOP SHOWING HIGH LEVEL MOISTURE FROM
TS LOWELL BEGINNING TO MOVE NORTH OVER SOUTHERN AZ WITH THE MID
LEVEL MOISTURE EXPECTED LATE TONIGHT INTO THURSDAY WHICH WILL
MOISTEN UP THE ATMOSPHERE SOME.  WHILE THE TIMING OF THE SYSTEM IS
NOT IDEAL (A BIT LATE) IT SHOULD BE GOOD ENOUGH TO HELP FIRE OFF
CONVECTION THURSDAY AFTERNOON INTO THURSDAY NIGHT WITH SOMEWHAT OF A
FOCUS OVER CENTRAL/WESTERN PIMA COUNTY.  VARIETY OF HI RES MODELS
INDICATE PLENTY OF MID AND HIGH LEVEL CLOUDS AROUND WITH SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS.  I HAVE TWEAKED POPS UP SOME
FROM WHAT WE HAD...ESPECIALLY WEST FOR THE AFTERNOON AND EVENING
HOURS.  AS A RESULT OF THE ANTICIPATED INCREASE IN CLOUDS AND
SHOWERS WE WILL HAVE ANOTHER COOLER THAN NORMAL DAY.

FOR FRIDAY...THE UPPER LOW...ACTUALLY AN OPEN TROUGH BY THIS POINT
WILL MOVE NE OF THE AREA WITH SOMEWHAT DRIER AIR MOVING OVER THE
REGION AT THE MID AND HIGH LEVELS WITH THE EXCEPTION OF ALONG THE
ITRNL BORDER WHICH WILL DIMINISH THE SHOWER AND THUNDERSTORM THREAT
AREAS FROM TUCSON NORTH AND WEST.  ANOTHER COOLER THAN NORMAL DAY
THANKS TO A BOTTOMING OUT OF HEIGHTS AND THICKNESS WITH THE PASSING
TROUGH.

FOR THE WEEKEND THROUGH MONDAY THERE WILL BE WESTERLY FLOW ACROSS
THE REGION LIMITING THE ATMOSPHERIC MOISTURE TO SLIGHTLY BELOW
NORMAL LEVELS.  STILL ENOUGH FOR ISOLATED TO SCATTERED CONVECTION
BUT PRIMARILY OVER SOUTH AND EAST OF TUCSON.  WITH FEWER CLOUDS AND
REBOUNDING THICKNESS VALUES HIGH TEMPERATURES ARE EXPECTED TO
REBOUND TO NORMAL LEVELS.

FOR THE MIDDLE OF NEXT WEEK SOME QUESTIONS ARISE DUE TO A POTENTIAL
TROPICAL SYSTEM OVER THE EASTERN PACIFIC.  THE QUESTION RELATES TO
HOW MUCH MOISTURE MAY BE TOSSED OUR WAY AND WHEN AS THE SYSTEM HEADS
OUT TO SEA.  IF LITTLE TO NONE OF THIS TROPICAL MOISTURE MAKES IT
THIS FAR NORTH WE WILL CONTINUE TO HAVE LESS THAN NORMAL CONVECTION
ACROSS THE AREA.  IF IT MANAGES TO MAKE IT HERE IT WILL BE MORE
ACTIVE.  WITHOUT A CLEAR SIGNAL AT THIS TIME I HAVE LEFT THE
FORECAST AS IS WHICH IS A LOW GRADE MONSOON FORECAST WITH NEAR
NORMAL TEMPERATURES.  CERNIGLIA

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON














000
FXUS65 KTWC 210406 CCA
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
906 PM MST WED AUG 20 2014

.SYNOPSIS...AN UPPER LOW OVER SOUTHERN CALIFORNIA WILL MOVE ACROSS
NORTHERN ARIZONA LATE THURSDAY NIGHT AND EARLY FRIDAY WITH SCATTERED
SHOWERS AND THUNDERSTORMS EXPECTED THURSDAY AFTERNOON AND NIGHT.
DRIER AIR BEHIND THE LOW WILL LIMIT CONVECTION TO MAINLY EASTERN AND
SOUTHERN AREAS FRIDAY THROUGH THE WEEKEND.  AFTER A COUPLE OF COOLER
THAN NORMAL DAYS...HIGH TEMPERATURES WILL WARM BACK UP TO NORMAL
OVER THE WEEKEND.

&&

.DISCUSSION...IT WAS A RELATIVELY DOWN DAY FOR CONVECTION ACROSS
SOUTHEAST ARIZONA AS SHOWERS AND THUNDERSTORMS GENERALLY STRUGGLED
AWAY FROM HIGHER TERRAIN AREAS. THE ONE EXCEPTION WAS EARLIER THIS
EVENING ACROSS CENTRAL AND WESTERN PIMA COUNTY WHERE A FEW SPOTS HAD
ONE TO TWO INCHES OF RAINFALL. THESE SHOWERS AND STORMS HAVE JUST
ABOUT DISSIPATED THOUGH BASED ON LATEST RADAR IMAGERY.
MEANWHILE...MOSTLY CLOUDY SKIES PREVAIL FOR AREAS FROM TUCSON
WESTWARD...WITH MOSTLY CLEAR TO PARTLY CLOUDY SKIES EAST OF TUCSON.

THERE IS A CONSIDERABLE AMOUNT OF MID/UPPER LEVEL MOISTURE THAT IS
STREAMING TO THE NORTHEAST FROM THE BAJA REGION...MOST OF WHICH IS
ATTRIBUTED TO TROPICAL STORM LOWELL. THE OTHER MAJOR FEATURE IS AN
ANOMALOUS UPPER LEVEL LOW THAT IS ALONG THE SOUTHERN CALIFORNIA
COAST AT THIS TIME. THE BIG QUESTION HEADING INTO THURSDAY WILL BE
HOW MUCH CLOUD COVERAGE WILL LIMIT INSTABILITY AND THUS CONVECTION
AS THERE WILL CERTAINLY BE FAVORABLE DYNAMICS EAST OF THE UPPER LOW
TO WORK WITH DURING THE DAY THURSDAY. MADE SOME MINOR TWEAKS TO THE
GRIDS BY INCREASING POPS AND SKY COVERAGE ACROSS THE CENTRAL AND
WESTERN DESERTS THROUGH THURSDAY MORNING AS SOME SHOWERS ARE
POSSIBLE WITH ANY EMBEDDED DISTURBANCES IN THE MID/UPPER LEVEL
MOISTURE PLUME. SEE PREVIOUS FORECAST DISCUSSION BELOW FOR
ADDITIONAL INFORMATION.

&&

.AVIATION...VALID THRU 21/00Z.
BKN-OVC SKIES ABOVE 10K FT AGL MAINLY FROM KTUS WESTWARD INTO
THURSDAY MORNING WITH SCT-BKN CLOUDS EAST OF KTUS. CHC OF -SHRA
ACTIVITY WILL GENERALLY BE LOW DURING THE OVERNIGHT HOURS WITH THE
BEST CHANCES WEST OF KTUS. AFTER 22/18Z SCT SHRA/TSRA ARE EXPECTED
TO DEVELOP ACROSS SOUTHEAST ARIZONA...BUT CONFIDENCE TOO LOW ON
TIMING AND LOCATION TO INCLUDE IN ANY TAF SITES. WINDS WILL
GENERALLY REMAIN LIGHT AND LESS THAN 10 KTS...THOUGH THUNDERSTORMS
THURSDAY WOULD RESULT IN GUSTY AND ERRATIC WINDS.

&&

.FIRE WEATHER...ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS ARE EXPECTED THROUGH EARLY NEXT WEEK. HOWEVER...THE
OVERALL TREND IN THUNDERSTORM ACTIVITY WILL BE DIMINISHED FROM
RECENT WEEKS. THE STRONGER THUNDERSTORMS WILL STILL PRODUCE
STRONG...GUSTY AND ERRATIC WINDS. OUTSIDE OF THE THUNDERSTORM
OUTFLOWS...20-FOOT WINDS WILL EXHIBIT NORMAL DIURNAL TRENDS AND WILL
BE MOSTLY LESS THAN 15 MPH. ALSO...RELATIVE HUMIDITY VALUES WILL
FALL A BIT LOWER THAN RECENT WEEKS DUE TO SOME DRYING IN THE
ATMOSPHERE...BUT WE WILL REMAIN ABOVE CRITIC RELATIVE HUMIDITY
THRESHOLDS THROUGH EARLY NEXT WEEK.

&&

.PREV DISCUSSION...SOMEWHAT INTERESTING WEATHER THE NEXT 36 HOURS AS
THE UPPER LOW MOVING OVER SOUTHERN CALIFORNIA OPENS UP AND MOVES
NORTHEAST ACROSS CENTRAL/NORTHERN ARIZONA LATER THURSDAY NIGHT INTO
FRIDAY MORNING.  WATER VAPOR LOOP SHOWING HIGH LEVEL MOISTURE FROM
TS LOWELL BEGINNING TO MOVE NORTH OVER SOUTHERN AZ WITH THE MID
LEVEL MOISTURE EXPECTED LATE TONIGHT INTO THURSDAY WHICH WILL
MOISTEN UP THE ATMOSPHERE SOME.  WHILE THE TIMING OF THE SYSTEM IS
NOT IDEAL (A BIT LATE) IT SHOULD BE GOOD ENOUGH TO HELP FIRE OFF
CONVECTION THURSDAY AFTERNOON INTO THURSDAY NIGHT WITH SOMEWHAT OF A
FOCUS OVER CENTRAL/WESTERN PIMA COUNTY.  VARIETY OF HI RES MODELS
INDICATE PLENTY OF MID AND HIGH LEVEL CLOUDS AROUND WITH SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS.  I HAVE TWEAKED POPS UP SOME
FROM WHAT WE HAD...ESPECIALLY WEST FOR THE AFTERNOON AND EVENING
HOURS.  AS A RESULT OF THE ANTICIPATED INCREASE IN CLOUDS AND
SHOWERS WE WILL HAVE ANOTHER COOLER THAN NORMAL DAY.

FOR FRIDAY...THE UPPER LOW...ACTUALLY AN OPEN TROUGH BY THIS POINT
WILL MOVE NE OF THE AREA WITH SOMEWHAT DRIER AIR MOVING OVER THE
REGION AT THE MID AND HIGH LEVELS WITH THE EXCEPTION OF ALONG THE
ITRNL BORDER WHICH WILL DIMINISH THE SHOWER AND THUNDERSTORM THREAT
AREAS FROM TUCSON NORTH AND WEST.  ANOTHER COOLER THAN NORMAL DAY
THANKS TO A BOTTOMING OUT OF HEIGHTS AND THICKNESS WITH THE PASSING
TROUGH.

FOR THE WEEKEND THROUGH MONDAY THERE WILL BE WESTERLY FLOW ACROSS
THE REGION LIMITING THE ATMOSPHERIC MOISTURE TO SLIGHTLY BELOW
NORMAL LEVELS.  STILL ENOUGH FOR ISOLATED TO SCATTERED CONVECTION
BUT PRIMARILY OVER SOUTH AND EAST OF TUCSON.  WITH FEWER CLOUDS AND
REBOUNDING THICKNESS VALUES HIGH TEMPERATURES ARE EXPECTED TO
REBOUND TO NORMAL LEVELS.

FOR THE MIDDLE OF NEXT WEEK SOME QUESTIONS ARISE DUE TO A POTENTIAL
TROPICAL SYSTEM OVER THE EASTERN PACIFIC.  THE QUESTION RELATES TO
HOW MUCH MOISTURE MAY BE TOSSED OUR WAY AND WHEN AS THE SYSTEM HEADS
OUT TO SEA.  IF LITTLE TO NONE OF THIS TROPICAL MOISTURE MAKES IT
THIS FAR NORTH WE WILL CONTINUE TO HAVE LESS THAN NORMAL CONVECTION
ACROSS THE AREA.  IF IT MANAGES TO MAKE IT HERE IT WILL BE MORE
ACTIVE.  WITHOUT A CLEAR SIGNAL AT THIS TIME I HAVE LEFT THE
FORECAST AS IS WHICH IS A LOW GRADE MONSOON FORECAST WITH NEAR
NORMAL TEMPERATURES.  CERNIGLIA

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON













000
FXUS65 KTWC 210406 CCA
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
906 PM MST WED AUG 20 2014

.SYNOPSIS...AN UPPER LOW OVER SOUTHERN CALIFORNIA WILL MOVE ACROSS
NORTHERN ARIZONA LATE THURSDAY NIGHT AND EARLY FRIDAY WITH SCATTERED
SHOWERS AND THUNDERSTORMS EXPECTED THURSDAY AFTERNOON AND NIGHT.
DRIER AIR BEHIND THE LOW WILL LIMIT CONVECTION TO MAINLY EASTERN AND
SOUTHERN AREAS FRIDAY THROUGH THE WEEKEND.  AFTER A COUPLE OF COOLER
THAN NORMAL DAYS...HIGH TEMPERATURES WILL WARM BACK UP TO NORMAL
OVER THE WEEKEND.

&&

.DISCUSSION...IT WAS A RELATIVELY DOWN DAY FOR CONVECTION ACROSS
SOUTHEAST ARIZONA AS SHOWERS AND THUNDERSTORMS GENERALLY STRUGGLED
AWAY FROM HIGHER TERRAIN AREAS. THE ONE EXCEPTION WAS EARLIER THIS
EVENING ACROSS CENTRAL AND WESTERN PIMA COUNTY WHERE A FEW SPOTS HAD
ONE TO TWO INCHES OF RAINFALL. THESE SHOWERS AND STORMS HAVE JUST
ABOUT DISSIPATED THOUGH BASED ON LATEST RADAR IMAGERY.
MEANWHILE...MOSTLY CLOUDY SKIES PREVAIL FOR AREAS FROM TUCSON
WESTWARD...WITH MOSTLY CLEAR TO PARTLY CLOUDY SKIES EAST OF TUCSON.

THERE IS A CONSIDERABLE AMOUNT OF MID/UPPER LEVEL MOISTURE THAT IS
STREAMING TO THE NORTHEAST FROM THE BAJA REGION...MOST OF WHICH IS
ATTRIBUTED TO TROPICAL STORM LOWELL. THE OTHER MAJOR FEATURE IS AN
ANOMALOUS UPPER LEVEL LOW THAT IS ALONG THE SOUTHERN CALIFORNIA
COAST AT THIS TIME. THE BIG QUESTION HEADING INTO THURSDAY WILL BE
HOW MUCH CLOUD COVERAGE WILL LIMIT INSTABILITY AND THUS CONVECTION
AS THERE WILL CERTAINLY BE FAVORABLE DYNAMICS EAST OF THE UPPER LOW
TO WORK WITH DURING THE DAY THURSDAY. MADE SOME MINOR TWEAKS TO THE
GRIDS BY INCREASING POPS AND SKY COVERAGE ACROSS THE CENTRAL AND
WESTERN DESERTS THROUGH THURSDAY MORNING AS SOME SHOWERS ARE
POSSIBLE WITH ANY EMBEDDED DISTURBANCES IN THE MID/UPPER LEVEL
MOISTURE PLUME. SEE PREVIOUS FORECAST DISCUSSION BELOW FOR
ADDITIONAL INFORMATION.

&&

.AVIATION...VALID THRU 21/00Z.
BKN-OVC SKIES ABOVE 10K FT AGL MAINLY FROM KTUS WESTWARD INTO
THURSDAY MORNING WITH SCT-BKN CLOUDS EAST OF KTUS. CHC OF -SHRA
ACTIVITY WILL GENERALLY BE LOW DURING THE OVERNIGHT HOURS WITH THE
BEST CHANCES WEST OF KTUS. AFTER 22/18Z SCT SHRA/TSRA ARE EXPECTED
TO DEVELOP ACROSS SOUTHEAST ARIZONA...BUT CONFIDENCE TOO LOW ON
TIMING AND LOCATION TO INCLUDE IN ANY TAF SITES. WINDS WILL
GENERALLY REMAIN LIGHT AND LESS THAN 10 KTS...THOUGH THUNDERSTORMS
THURSDAY WOULD RESULT IN GUSTY AND ERRATIC WINDS.

&&

.FIRE WEATHER...ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS ARE EXPECTED THROUGH EARLY NEXT WEEK. HOWEVER...THE
OVERALL TREND IN THUNDERSTORM ACTIVITY WILL BE DIMINISHED FROM
RECENT WEEKS. THE STRONGER THUNDERSTORMS WILL STILL PRODUCE
STRONG...GUSTY AND ERRATIC WINDS. OUTSIDE OF THE THUNDERSTORM
OUTFLOWS...20-FOOT WINDS WILL EXHIBIT NORMAL DIURNAL TRENDS AND WILL
BE MOSTLY LESS THAN 15 MPH. ALSO...RELATIVE HUMIDITY VALUES WILL
FALL A BIT LOWER THAN RECENT WEEKS DUE TO SOME DRYING IN THE
ATMOSPHERE...BUT WE WILL REMAIN ABOVE CRITIC RELATIVE HUMIDITY
THRESHOLDS THROUGH EARLY NEXT WEEK.

&&

.PREV DISCUSSION...SOMEWHAT INTERESTING WEATHER THE NEXT 36 HOURS AS
THE UPPER LOW MOVING OVER SOUTHERN CALIFORNIA OPENS UP AND MOVES
NORTHEAST ACROSS CENTRAL/NORTHERN ARIZONA LATER THURSDAY NIGHT INTO
FRIDAY MORNING.  WATER VAPOR LOOP SHOWING HIGH LEVEL MOISTURE FROM
TS LOWELL BEGINNING TO MOVE NORTH OVER SOUTHERN AZ WITH THE MID
LEVEL MOISTURE EXPECTED LATE TONIGHT INTO THURSDAY WHICH WILL
MOISTEN UP THE ATMOSPHERE SOME.  WHILE THE TIMING OF THE SYSTEM IS
NOT IDEAL (A BIT LATE) IT SHOULD BE GOOD ENOUGH TO HELP FIRE OFF
CONVECTION THURSDAY AFTERNOON INTO THURSDAY NIGHT WITH SOMEWHAT OF A
FOCUS OVER CENTRAL/WESTERN PIMA COUNTY.  VARIETY OF HI RES MODELS
INDICATE PLENTY OF MID AND HIGH LEVEL CLOUDS AROUND WITH SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS.  I HAVE TWEAKED POPS UP SOME
FROM WHAT WE HAD...ESPECIALLY WEST FOR THE AFTERNOON AND EVENING
HOURS.  AS A RESULT OF THE ANTICIPATED INCREASE IN CLOUDS AND
SHOWERS WE WILL HAVE ANOTHER COOLER THAN NORMAL DAY.

FOR FRIDAY...THE UPPER LOW...ACTUALLY AN OPEN TROUGH BY THIS POINT
WILL MOVE NE OF THE AREA WITH SOMEWHAT DRIER AIR MOVING OVER THE
REGION AT THE MID AND HIGH LEVELS WITH THE EXCEPTION OF ALONG THE
ITRNL BORDER WHICH WILL DIMINISH THE SHOWER AND THUNDERSTORM THREAT
AREAS FROM TUCSON NORTH AND WEST.  ANOTHER COOLER THAN NORMAL DAY
THANKS TO A BOTTOMING OUT OF HEIGHTS AND THICKNESS WITH THE PASSING
TROUGH.

FOR THE WEEKEND THROUGH MONDAY THERE WILL BE WESTERLY FLOW ACROSS
THE REGION LIMITING THE ATMOSPHERIC MOISTURE TO SLIGHTLY BELOW
NORMAL LEVELS.  STILL ENOUGH FOR ISOLATED TO SCATTERED CONVECTION
BUT PRIMARILY OVER SOUTH AND EAST OF TUCSON.  WITH FEWER CLOUDS AND
REBOUNDING THICKNESS VALUES HIGH TEMPERATURES ARE EXPECTED TO
REBOUND TO NORMAL LEVELS.

FOR THE MIDDLE OF NEXT WEEK SOME QUESTIONS ARISE DUE TO A POTENTIAL
TROPICAL SYSTEM OVER THE EASTERN PACIFIC.  THE QUESTION RELATES TO
HOW MUCH MOISTURE MAY BE TOSSED OUR WAY AND WHEN AS THE SYSTEM HEADS
OUT TO SEA.  IF LITTLE TO NONE OF THIS TROPICAL MOISTURE MAKES IT
THIS FAR NORTH WE WILL CONTINUE TO HAVE LESS THAN NORMAL CONVECTION
ACROSS THE AREA.  IF IT MANAGES TO MAKE IT HERE IT WILL BE MORE
ACTIVE.  WITHOUT A CLEAR SIGNAL AT THIS TIME I HAVE LEFT THE
FORECAST AS IS WHICH IS A LOW GRADE MONSOON FORECAST WITH NEAR
NORMAL TEMPERATURES.  CERNIGLIA

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON













000
FXUS65 KTWC 202149 CCA
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
240 PM MST WED AUG 20 2014

.CORRECTED...CORRECTED THE TIME.

.SYNOPSIS...AN UPPER LOW OVER SOUTHERN CALIFORNIA WILL MOVE ACROSS
NORTHERN ARIZONA LATE THURSDAY NIGHT AND EARLY FRIDAY WITH SCATTERED
SHOWERS AND THUNDERSTORMS EXPECTED THURSDAY AFTERNOON AND NIGHT.
DRIER AIR BEHIND THE LOW WILL LIMIT CONVECTION TO MAINLY EASTERN AND
SOUTHERN AREAS FRIDAY THROUGH THE WEEKEND.  AFTER A COUPLE OF COOLER
THAN NORMAL DAYS...HIGH TEMPERATURES WILL WARM BACK UP TO NORMAL
OVER THE WEEKEND.

&&

.DISCUSSION...SOMEWHAT INTERESTING WEATHER THE NEXT 36 HOURS AS THE
UPPER LOW MOVING OVER SOUTHERN CALIFORNIA OPENS UP AND MOVES
NORTHEAST ACROSS CENTRAL/NORTHERN ARIZONA LATER THURSDAY NIGHT INTO
FRIDAY MORNING.  WATER VAPOR LOOP SHOWING HIGH LEVEL MOISTURE FROM
TS LOWELL BEGINNING TO MOVE NORTH OVER SOUTHERN AZ WITH THE MID
LEVEL MOISTURE EXPECTED LATE TONIGHT INTO THURSDAY WHICH WILL
MOISTEN UP THE ATMOSPHERE SOME.  WHILE THE TIMING OF THE SYSTEM IS
NOT IDEAL (A BIT LATE) IT SHOULD BE GOOD ENOUGH TO HELP FIRE OFF
CONVECTION THURSDAY AFTERNOON INTO THURSDAY NIGHT WITH SOMEWHAT OF A
FOCUS OVER CENTRAL/WESTERN PIMA COUNTY.  VARIETY OF HI RES MODELS
INDICATE PLENTY OF MID AND HIGH LEVEL CLOUDS AROUND WITH SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS.  I HAVE TWEAKED POPS UP SOME
FROM WHAT WE HAD...ESPECIALLY WEST FOR THE AFTERNOON AND EVENING
HOURS.  AS A RESULT OF THE ANTICIPATED INCREASE IN CLOUDS AND
SHOWERS WE WILL HAVE ANOTHER COOLER THAN NORMAL DAY.

FOR FRIDAY...THE UPPER LOW...ACTUALLY AN OPEN TROUGH BY THIS POINT
WILL MOVE NE OF THE AREA WITH SOMEWHAT DRIER AIR MOVING OVER THE
REGION AT THE MID AND HIGH LEVELS WITH THE EXCEPTION OF ALONG THE
ITRNL BORDER WHICH WILL DIMINISH THE SHOWER AND THUNDERSTORM THREAT
AREAS FROM TUCSON NORTH AND WEST.  ANOTHER COOLER THAN NORMAL DAY
THANKS TO A BOTTOMING OUT OF HEIGHTS AND THICKNESS WITH THE PASSING
TROUGH.

FOR THE WEEKEND THROUGH MONDAY THERE WILL BE WESTERLY FLOW ACROSS
THE REGION LIMITING THE ATMOSPHERIC MOISTURE TO SLIGHTLY BELOW
NORMAL LEVELS.  STILL ENOUGH FOR ISOLATED TO SCATTERED CONVECTION
BUT PRIMARILY OVER SOUTH AND EAST OF TUCSON.  WITH FEWER CLOUDS AND
REBOUNDING THICKNESS VALUES HIGH TEMPERATURES ARE EXPECTED TO
REBOUND TO NORMAL LEVELS.

FOR THE MIDDLE OF NEXT WEEK SOME QUESTIONS ARISE DUE TO A POTENTIAL
TROPICAL SYSTEM OVER THE EASTERN PACIFIC.  THE QUESTION RELATES TO
HOW MUCH MOISTURE MAY BE TOSSED OUR WAY AND WHEN AS THE SYSTEM HEADS
OUT TO SEA.  IF LITTLE TO NONE OF THIS TROPICAL MOISTURE MAKES IT
THIS FAR NORTH WE WILL CONTINUE TO HAVE LESS THAN NORMAL CONVECTION
ACROSS THE AREA.  IF IT MANAGES TO MAKE IT HERE IT WILL BE MORE
ACTIVE.  WITHOUT A CLEAR SIGNAL AT THIS TIME I HAVE LEFT THE
FORECAST AS IS WHICH IS A LOW GRADE MONSOON FORECAST WITH NEAR
NORMAL TEMPERATURES.  CERNIGLIA

&&

.AVIATION...VALID THRU 21/12Z.
EXPECT ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS THROUGH ABOUT
04Z. HOWEVER...CONFIDENCE IS CURRENTLY TOO LOW TO INSERT TS REMARKS
AT ANY TAF SITE. FELT MOST CONFIDENT IN STORMS IMPACTING KOLS TODAY
SO HAVE MENTIONED VCSH IN THAT CASE. OTHERWISE...WINDS WILL
GENERALLY REMAIN LIGHT AND LESS THAN 10 KTS. THUNDERSTORMS WOULD
PROMOTE GUSTY AND ERRATIC WINDS OF COURSE. VFR CONDITIONS EXPECTED
AS WELL THROUGH THE 18Z TAF PERIOD.

&&

.FIRE WEATHER...ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS ARE EXPECTED THROUGH EARLY NEXT WEEK. HOWEVER...THE
OVERALL TREND IN THUNDERSTORM ACTIVITY WILL BE DIMINISHED FROM
RECENT WEEKS. THE STRONGER THUNDERSTORMS WILL STILL PRODUCE
STRONG...GUSTY AND ERRATIC WINDS. OUTSIDE OF THE THUNDERSTORM
OUTFLOWS...20-FOOT WINDS WILL EXHIBIT NORMAL DIURNAL TRENDS AND WILL
BE MOSTLY LESS THAN 15 MPH. ALSO...RELATIVE HUMIDITY VALUES WILL
FALL A BIT LOWER THAN RECENT WEEKS DUE TO SOME DRYING IN THE
ATMOSPHERE...BUT WE WILL REMAIN ABOVE CRITIC RELATIVE HUMIDITY
THRESHOLDS THROUGH EARLY NEXT WEEK.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON











000
FXUS65 KTWC 202149 CCA
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
240 PM MST WED AUG 20 2014

.CORRECTED...CORRECTED THE TIME.

.SYNOPSIS...AN UPPER LOW OVER SOUTHERN CALIFORNIA WILL MOVE ACROSS
NORTHERN ARIZONA LATE THURSDAY NIGHT AND EARLY FRIDAY WITH SCATTERED
SHOWERS AND THUNDERSTORMS EXPECTED THURSDAY AFTERNOON AND NIGHT.
DRIER AIR BEHIND THE LOW WILL LIMIT CONVECTION TO MAINLY EASTERN AND
SOUTHERN AREAS FRIDAY THROUGH THE WEEKEND.  AFTER A COUPLE OF COOLER
THAN NORMAL DAYS...HIGH TEMPERATURES WILL WARM BACK UP TO NORMAL
OVER THE WEEKEND.

&&

.DISCUSSION...SOMEWHAT INTERESTING WEATHER THE NEXT 36 HOURS AS THE
UPPER LOW MOVING OVER SOUTHERN CALIFORNIA OPENS UP AND MOVES
NORTHEAST ACROSS CENTRAL/NORTHERN ARIZONA LATER THURSDAY NIGHT INTO
FRIDAY MORNING.  WATER VAPOR LOOP SHOWING HIGH LEVEL MOISTURE FROM
TS LOWELL BEGINNING TO MOVE NORTH OVER SOUTHERN AZ WITH THE MID
LEVEL MOISTURE EXPECTED LATE TONIGHT INTO THURSDAY WHICH WILL
MOISTEN UP THE ATMOSPHERE SOME.  WHILE THE TIMING OF THE SYSTEM IS
NOT IDEAL (A BIT LATE) IT SHOULD BE GOOD ENOUGH TO HELP FIRE OFF
CONVECTION THURSDAY AFTERNOON INTO THURSDAY NIGHT WITH SOMEWHAT OF A
FOCUS OVER CENTRAL/WESTERN PIMA COUNTY.  VARIETY OF HI RES MODELS
INDICATE PLENTY OF MID AND HIGH LEVEL CLOUDS AROUND WITH SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS.  I HAVE TWEAKED POPS UP SOME
FROM WHAT WE HAD...ESPECIALLY WEST FOR THE AFTERNOON AND EVENING
HOURS.  AS A RESULT OF THE ANTICIPATED INCREASE IN CLOUDS AND
SHOWERS WE WILL HAVE ANOTHER COOLER THAN NORMAL DAY.

FOR FRIDAY...THE UPPER LOW...ACTUALLY AN OPEN TROUGH BY THIS POINT
WILL MOVE NE OF THE AREA WITH SOMEWHAT DRIER AIR MOVING OVER THE
REGION AT THE MID AND HIGH LEVELS WITH THE EXCEPTION OF ALONG THE
ITRNL BORDER WHICH WILL DIMINISH THE SHOWER AND THUNDERSTORM THREAT
AREAS FROM TUCSON NORTH AND WEST.  ANOTHER COOLER THAN NORMAL DAY
THANKS TO A BOTTOMING OUT OF HEIGHTS AND THICKNESS WITH THE PASSING
TROUGH.

FOR THE WEEKEND THROUGH MONDAY THERE WILL BE WESTERLY FLOW ACROSS
THE REGION LIMITING THE ATMOSPHERIC MOISTURE TO SLIGHTLY BELOW
NORMAL LEVELS.  STILL ENOUGH FOR ISOLATED TO SCATTERED CONVECTION
BUT PRIMARILY OVER SOUTH AND EAST OF TUCSON.  WITH FEWER CLOUDS AND
REBOUNDING THICKNESS VALUES HIGH TEMPERATURES ARE EXPECTED TO
REBOUND TO NORMAL LEVELS.

FOR THE MIDDLE OF NEXT WEEK SOME QUESTIONS ARISE DUE TO A POTENTIAL
TROPICAL SYSTEM OVER THE EASTERN PACIFIC.  THE QUESTION RELATES TO
HOW MUCH MOISTURE MAY BE TOSSED OUR WAY AND WHEN AS THE SYSTEM HEADS
OUT TO SEA.  IF LITTLE TO NONE OF THIS TROPICAL MOISTURE MAKES IT
THIS FAR NORTH WE WILL CONTINUE TO HAVE LESS THAN NORMAL CONVECTION
ACROSS THE AREA.  IF IT MANAGES TO MAKE IT HERE IT WILL BE MORE
ACTIVE.  WITHOUT A CLEAR SIGNAL AT THIS TIME I HAVE LEFT THE
FORECAST AS IS WHICH IS A LOW GRADE MONSOON FORECAST WITH NEAR
NORMAL TEMPERATURES.  CERNIGLIA

&&

.AVIATION...VALID THRU 21/12Z.
EXPECT ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS THROUGH ABOUT
04Z. HOWEVER...CONFIDENCE IS CURRENTLY TOO LOW TO INSERT TS REMARKS
AT ANY TAF SITE. FELT MOST CONFIDENT IN STORMS IMPACTING KOLS TODAY
SO HAVE MENTIONED VCSH IN THAT CASE. OTHERWISE...WINDS WILL
GENERALLY REMAIN LIGHT AND LESS THAN 10 KTS. THUNDERSTORMS WOULD
PROMOTE GUSTY AND ERRATIC WINDS OF COURSE. VFR CONDITIONS EXPECTED
AS WELL THROUGH THE 18Z TAF PERIOD.

&&

.FIRE WEATHER...ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS ARE EXPECTED THROUGH EARLY NEXT WEEK. HOWEVER...THE
OVERALL TREND IN THUNDERSTORM ACTIVITY WILL BE DIMINISHED FROM
RECENT WEEKS. THE STRONGER THUNDERSTORMS WILL STILL PRODUCE
STRONG...GUSTY AND ERRATIC WINDS. OUTSIDE OF THE THUNDERSTORM
OUTFLOWS...20-FOOT WINDS WILL EXHIBIT NORMAL DIURNAL TRENDS AND WILL
BE MOSTLY LESS THAN 15 MPH. ALSO...RELATIVE HUMIDITY VALUES WILL
FALL A BIT LOWER THAN RECENT WEEKS DUE TO SOME DRYING IN THE
ATMOSPHERE...BUT WE WILL REMAIN ABOVE CRITIC RELATIVE HUMIDITY
THRESHOLDS THROUGH EARLY NEXT WEEK.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON










000
FXUS65 KTWC 202140
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
240 AM MST WED AUG 20 2014

.SYNOPSIS...AN UPPER LOW OVER SOUTHERN CALIFORNIA WILL MOVE ACROSS
NORTHERN ARIZONA LATE THURSDAY NIGHT AND EARLY FRIDAY WITH SCATTERED
SHOWERS AND THUNDERSTORMS EXPECTED THURSDAY AFTERNOON AND NIGHT.
DRIER AIR BEHIND THE LOW WILL LIMIT CONVECTION TO MAINLY EASTERN AND
SOUTHERN AREAS FRIDAY THROUGH THE WEEKEND.  AFTER A COUPLE OF COOLER
THAN NORMAL DAYS...HIGH TEMPERATURES WILL WARM BACK UP TO NORMAL
OVER THE WEEKEND.

&&

.DISCUSSION...SOMEWHAT INTERESTING WEATHER THE NEXT 36 HOURS AS THE
UPPER LOW MOVING OVER SOUTHERN CALIFORNIA OPENS UP AND MOVES
NORTHEAST ACROSS CENTRAL/NORTHERN ARIZONA LATER THURSDAY NIGHT INTO
FRIDAY MORNING.  WATER VAPOR LOOP SHOWING HIGH LEVEL MOISTURE FROM
TS LOWELL BEGINNING TO MOVE NORTH OVER SOUTHERN AZ WITH THE MID
LEVEL MOISTURE EXPECTED LATE TONIGHT INTO THURSDAY WHICH WILL
MOISTEN UP THE ATMOSPHERE SOME.  WHILE THE TIMING OF THE SYSTEM IS
NOT IDEAL (A BIT LATE) IT SHOULD BE GOOD ENOUGH TO HELP FIRE OFF
CONVECTION THURSDAY AFTERNOON INTO THURSDAY NIGHT WITH SOMEWHAT OF A
FOCUS OVER CENTRAL/WESTERN PIMA COUNTY.  VARIETY OF HI RES MODELS
INDICATE PLENTY OF MID AND HIGH LEVEL CLOUDS AROUND WITH SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS.  I HAVE TWEAKED POPS UP SOME
FROM WHAT WE HAD...ESPECIALLY WEST FOR THE AFTERNOON AND EVENING
HOURS.  AS A RESULT OF THE ANTICIPATED INCREASE IN CLOUDS AND
SHOWERS WE WILL HAVE ANOTHER COOLER THAN NORMAL DAY.

FOR FRIDAY...THE UPPER LOW...ACTUALLY AN OPEN TROUGH BY THIS POINT
WILL MOVE NE OF THE AREA WITH SOMEWHAT DRIER AIR MOVING OVER THE
REGION AT THE MID AND HIGH LEVELS WITH THE EXCEPTION OF ALONG THE
ITRNL BORDER WHICH WILL DIMINISH THE SHOWER AND THUNDERSTORM THREAT
AREAS FROM TUCSON NORTH AND WEST.  ANOTHER COOLER THAN NORMAL DAY
THANKS TO A BOTTOMING OUT OF HEIGHTS AND THICKNESS WITH THE PASSING
TROUGH.

FOR THE WEEKEND THROUGH MONDAY THERE WILL BE WESTERLY FLOW ACROSS
THE REGION LIMITING THE ATMOSPHERIC MOISTURE TO SLIGHTLY BELOW
NORMAL LEVELS.  STILL ENOUGH FOR ISOLATED TO SCATTERED CONVECTION
BUT PRIMARILY OVER SOUTH AND EAST OF TUCSON.  WITH FEWER CLOUDS AND
REBOUNDING THICKNESS VALUES HIGH TEMPERATURES ARE EXPECTED TO
REBOUND TO NORMAL LEVELS.

FOR THE MIDDLE OF NEXT WEEK SOME QUESTIONS ARISE DUE TO A POTENTIAL
TROPICAL SYSTEM OVER THE EASTERN PACIFIC.  THE QUESTION RELATES TO
HOW MUCH MOISTURE MAY BE TOSSED OUR WAY AND WHEN AS THE SYSTEM HEADS
OUT TO SEA.  IF LITTLE TO NONE OF THIS TROPICAL MOISTURE MAKES IT
THIS FAR NORTH WE WILL CONTINUE TO HAVE LESS THAN NORMAL CONVECTION
ACROSS THE AREA.  IF IT MANAGES TO MAKE IT HERE IT WILL BE MORE
ACTIVE.  WITHOUT A CLEAR SIGNAL AT THIS TIME I HAVE LEFT THE
FORECAST AS IS WHICH IS A LOW GRADE MONSOON FORECAST WITH NEAR
NORMAL TEMPERATURES.  CERNIGLIA

&&

.AVIATION...VALID THRU 21/12Z.
EXPECT ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS THROUGH ABOUT
04Z. HOWEVER...CONFIDENCE IS CURRENTLY TOO LOW TO INSERT TS REMARKS
AT ANY TAF SITE. FELT MOST CONFIDENT IN STORMS IMPACTING KOLS TODAY
SO HAVE MENTIONED VCSH IN THAT CASE. OTHERWISE...WINDS WILL
GENERALLY REMAIN LIGHT AND LESS THAN 10 KTS. THUNDERSTORMS WOULD
PROMOTE GUSTY AND ERRATIC WINDS OF COURSE. VFR CONDITIONS EXPECTED
AS WELL THROUGH THE 18Z TAF PERIOD.

&&

.FIRE WEATHER...ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS ARE EXPECTED THROUGH EARLY NEXT WEEK. HOWEVER...THE
OVERALL TREND IN THUNDERSTORM ACTIVITY WILL BE DIMINISHED FROM
RECENT WEEKS. THE STRONGER THUNDERSTORMS WILL STILL PRODUCE
STRONG...GUSTY AND ERRATIC WINDS. OUTSIDE OF THE THUNDERSTORM
OUTFLOWS...20-FOOT WINDS WILL EXHIBIT NORMAL DIURNAL TRENDS AND WILL
BE MOSTLY LESS THAN 15 MPH. ALSO...RELATIVE HUMIDITY VALUES WILL
FALL A BIT LOWER THAN RECENT WEEKS DUE TO SOME DRYING IN THE
ATMOSPHERE...BUT WE WILL REMAIN ABOVE CRITIC RELATIVE HUMIDITY
THRESHOLDS THROUGH EARLY NEXT WEEK.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON








000
FXUS65 KTWC 202140
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
240 AM MST WED AUG 20 2014

.SYNOPSIS...AN UPPER LOW OVER SOUTHERN CALIFORNIA WILL MOVE ACROSS
NORTHERN ARIZONA LATE THURSDAY NIGHT AND EARLY FRIDAY WITH SCATTERED
SHOWERS AND THUNDERSTORMS EXPECTED THURSDAY AFTERNOON AND NIGHT.
DRIER AIR BEHIND THE LOW WILL LIMIT CONVECTION TO MAINLY EASTERN AND
SOUTHERN AREAS FRIDAY THROUGH THE WEEKEND.  AFTER A COUPLE OF COOLER
THAN NORMAL DAYS...HIGH TEMPERATURES WILL WARM BACK UP TO NORMAL
OVER THE WEEKEND.

&&

.DISCUSSION...SOMEWHAT INTERESTING WEATHER THE NEXT 36 HOURS AS THE
UPPER LOW MOVING OVER SOUTHERN CALIFORNIA OPENS UP AND MOVES
NORTHEAST ACROSS CENTRAL/NORTHERN ARIZONA LATER THURSDAY NIGHT INTO
FRIDAY MORNING.  WATER VAPOR LOOP SHOWING HIGH LEVEL MOISTURE FROM
TS LOWELL BEGINNING TO MOVE NORTH OVER SOUTHERN AZ WITH THE MID
LEVEL MOISTURE EXPECTED LATE TONIGHT INTO THURSDAY WHICH WILL
MOISTEN UP THE ATMOSPHERE SOME.  WHILE THE TIMING OF THE SYSTEM IS
NOT IDEAL (A BIT LATE) IT SHOULD BE GOOD ENOUGH TO HELP FIRE OFF
CONVECTION THURSDAY AFTERNOON INTO THURSDAY NIGHT WITH SOMEWHAT OF A
FOCUS OVER CENTRAL/WESTERN PIMA COUNTY.  VARIETY OF HI RES MODELS
INDICATE PLENTY OF MID AND HIGH LEVEL CLOUDS AROUND WITH SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS.  I HAVE TWEAKED POPS UP SOME
FROM WHAT WE HAD...ESPECIALLY WEST FOR THE AFTERNOON AND EVENING
HOURS.  AS A RESULT OF THE ANTICIPATED INCREASE IN CLOUDS AND
SHOWERS WE WILL HAVE ANOTHER COOLER THAN NORMAL DAY.

FOR FRIDAY...THE UPPER LOW...ACTUALLY AN OPEN TROUGH BY THIS POINT
WILL MOVE NE OF THE AREA WITH SOMEWHAT DRIER AIR MOVING OVER THE
REGION AT THE MID AND HIGH LEVELS WITH THE EXCEPTION OF ALONG THE
ITRNL BORDER WHICH WILL DIMINISH THE SHOWER AND THUNDERSTORM THREAT
AREAS FROM TUCSON NORTH AND WEST.  ANOTHER COOLER THAN NORMAL DAY
THANKS TO A BOTTOMING OUT OF HEIGHTS AND THICKNESS WITH THE PASSING
TROUGH.

FOR THE WEEKEND THROUGH MONDAY THERE WILL BE WESTERLY FLOW ACROSS
THE REGION LIMITING THE ATMOSPHERIC MOISTURE TO SLIGHTLY BELOW
NORMAL LEVELS.  STILL ENOUGH FOR ISOLATED TO SCATTERED CONVECTION
BUT PRIMARILY OVER SOUTH AND EAST OF TUCSON.  WITH FEWER CLOUDS AND
REBOUNDING THICKNESS VALUES HIGH TEMPERATURES ARE EXPECTED TO
REBOUND TO NORMAL LEVELS.

FOR THE MIDDLE OF NEXT WEEK SOME QUESTIONS ARISE DUE TO A POTENTIAL
TROPICAL SYSTEM OVER THE EASTERN PACIFIC.  THE QUESTION RELATES TO
HOW MUCH MOISTURE MAY BE TOSSED OUR WAY AND WHEN AS THE SYSTEM HEADS
OUT TO SEA.  IF LITTLE TO NONE OF THIS TROPICAL MOISTURE MAKES IT
THIS FAR NORTH WE WILL CONTINUE TO HAVE LESS THAN NORMAL CONVECTION
ACROSS THE AREA.  IF IT MANAGES TO MAKE IT HERE IT WILL BE MORE
ACTIVE.  WITHOUT A CLEAR SIGNAL AT THIS TIME I HAVE LEFT THE
FORECAST AS IS WHICH IS A LOW GRADE MONSOON FORECAST WITH NEAR
NORMAL TEMPERATURES.  CERNIGLIA

&&

.AVIATION...VALID THRU 21/12Z.
EXPECT ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS THROUGH ABOUT
04Z. HOWEVER...CONFIDENCE IS CURRENTLY TOO LOW TO INSERT TS REMARKS
AT ANY TAF SITE. FELT MOST CONFIDENT IN STORMS IMPACTING KOLS TODAY
SO HAVE MENTIONED VCSH IN THAT CASE. OTHERWISE...WINDS WILL
GENERALLY REMAIN LIGHT AND LESS THAN 10 KTS. THUNDERSTORMS WOULD
PROMOTE GUSTY AND ERRATIC WINDS OF COURSE. VFR CONDITIONS EXPECTED
AS WELL THROUGH THE 18Z TAF PERIOD.

&&

.FIRE WEATHER...ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS ARE EXPECTED THROUGH EARLY NEXT WEEK. HOWEVER...THE
OVERALL TREND IN THUNDERSTORM ACTIVITY WILL BE DIMINISHED FROM
RECENT WEEKS. THE STRONGER THUNDERSTORMS WILL STILL PRODUCE
STRONG...GUSTY AND ERRATIC WINDS. OUTSIDE OF THE THUNDERSTORM
OUTFLOWS...20-FOOT WINDS WILL EXHIBIT NORMAL DIURNAL TRENDS AND WILL
BE MOSTLY LESS THAN 15 MPH. ALSO...RELATIVE HUMIDITY VALUES WILL
FALL A BIT LOWER THAN RECENT WEEKS DUE TO SOME DRYING IN THE
ATMOSPHERE...BUT WE WILL REMAIN ABOVE CRITIC RELATIVE HUMIDITY
THRESHOLDS THROUGH EARLY NEXT WEEK.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON







000
FXUS65 KTWC 201531
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
830 AM MST WED AUG 20 2014

.SYNOPSIS...SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS
WILL CONTINUE THROUGH FRIDAY WITH SOME STORMS PRODUCING HEAVY RAIN
AND GUSTY WINDS.  GRADUAL DRYING IS EXPECTED TO OCCUR THIS WEEKEND
INTO EARLY NEXT WEEK...HOWEVER ENOUGH MOISTURE WILL REMAIN FOR
ISOLATED TO SCATTERED THUNDERSTORMS.  BELOW NORMAL DAYTIME
TEMPERATURES WILL PREVAIL THROUGH FRIDAY FOLLOWED BY A WARMING TREND
THIS WEEKEND.

&&

.DISCUSSION...OTHER THAN A FEW PATCHES OF CLOUDS FAR EASTERN
SECTIONS SKIES ARE CLEAR THIS MORNING.  THE SOUNDING THIS MORNING
SHOWS A SIGNIFICANTLY DRIER MID AND UPPER LEVEL ATMOSPHERE BUT STILL
RATHER UNSTABLE THANKS TO PLENTY OF LOW LEVEL MOISTURE.  THE LOW
LEVEL MOISTURE WILL MIX OUT TO SOME EXTENT BUT SHOULD BE ENOUGH FOR
A FEW THUNDERSTORMS TO DEVELOP OVER THE HIGHER TERRAIN TODAY.  CU
ALREADY SHOWING UP OVER THE HUACHUCA MTNS ALREADY.  ANY STORMS THAT
DEVELOP WILL MOVE OFF TO THE NORTHEAST AND BE YOUR MORE TYPICAL RAIN
AND WIND PRODUCERS RATHER THAN THE HEAVY RAINERS OF LATE.  AS FAR AS
HIGH TEMPERATURES...WILL HAVE RELATIVELY LOW THICKNESS VALUES ACROSS
THE REGION WHICH WILL HOLD HI TEMPS A FEW DEGREES COOLER THAN
NORMAL.  THE WESTERN DESERTS WILL HAVE SIMILAR TEMPS TO YESTERDAY
WHILE AREAS EAST OF TUCSON...WHILE STILL COOLER THAN NORMAL WILL BE
UP TO 10 DEGREES WARMER THAN YESTERDAY THANKS TO MORE SUNSHINE.  NO
UPDATES NEEDED AT THIS TIME.
CERNIGLIA

THE REMAINDER OF THIS SECTION IS FROM THE PRECIOUS DISCUSSION.

TONIGHT...MODEL CROSS SECTIONS INDICATE THAT A BIT MORE MID-LEVEL
MOISTURE WILL BE PULLED FROM THE OUTER EDGE OF TS LOWELL INTO SW AZ
AS THE CLOSED LOW OFF THE SOUTHERN CALIFORNIA COAST SLOWLY MOVES
INLAND OVER SAN DIEGO. COULD SEE A FEW STORMS DEVELOP OVER OUR
WESTERN DESERTS LATE TONIGHT INTO THURSDAY MORNING.

THURSDAY LOOKS RATHER ACTIVE AS THE CLOSED LOW OPENS UP AS IT MOVES
INTO WESTERN ARIZONA. THUS EXPECT A RETURN TO SCATTERED AFTERNOON
AND EVENING SHOWERS AND THUNDERSTORMS. HIGHS SIMILAR TO WHAT IS
FORECAST FOR TODAY WHICH CONTINUES TO BE BELOW NORMAL.

FRIDAY...TROF AXIS WILL BE MOVING INTO WESTERN NEW MEXICO WITH DRIER
AIR FILTERING ACROSS THE AREA FROM THE WEST. PRECIPITABLE WATER
VALUES ARE PROGGED TO BE LESS THAN ONE INCH IN THE WHITES TO NEAR
1.50" ALONG THE INTNL BORDER. THIS WILL LIMIT THUNDERSTORM ACTIVITY
TO THE MOUNTAINS EAST OF TUCSON AND ALONG THE INTERNATIONAL BORDER
FROM NOGALES EAST. BELOW NORMAL HIGHS CONTINUE FOR ONE MORE DAY.

SATURDAY...THE PACIFIC UPPER TROF THAT KICKS OUR CURRENT LOW THRU
THE STATE ON FRIDAY WILL BE PASSING BY TO OUR NORTH. RATHER DRY
WESTERLY FLOW ALOFT WITH PRECIPITABLE WATER VALUES PROGGED TO RANGE
FROM 0.75"-1.25" DRIEST IN THE WHITES. THUNDERSTORM COVERAGE LESS
THAN FRIDAY BUT PRETTY MUCH IN THE SAME AREAS. WARMER WITH HIGHS
EDGING CLOSER TO NORMAL.

SUNDAY...TROFINESS REMAINING TO OUR NORTH WILL LIMIT ANY
THUNDERSTORM ACTIVITY TO MAINLY THE HIGHER TERRAIN E AND S OF
TUCSON. HIGHS WILL BE AT OR SLIGHTLY ABOVE NORMAL.

MONDAY AND TUESDAY...WILL MAINTAIN LOW GRADE MONSOON FORECAST AS
UPPER LEVEL TROFINESS REMAINS CLOSE TO THE STATE.

DEEPER MOISTURE MAY RETURN TO THE AREA THANKS TO A TROPICAL SYSTEM
MOVING CLOSE ENOUGH TO THE GULF OF CA TO SEND A SURGE OF MOISTURE
NORTH INTO THE STATE. TIME WILL TELL.

&&

.AVIATION...VALID THRU 21/18Z.
EXPECT ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS THIS
AFTERNOON...PERSISTING INTO THE EARLY EVENING HOURS.  THESE WILL
MAINLY HUG THE MOUNTAINS WITH THE KOLS AND KDUG TERMINALS MOST
LIKELY TO BE AFFECTED.  KTUS WILL LIKELY NOT HAVE ANY THUNDERSTORM
ACTIVITY TODAY.  MVFR VISIBILITIES AND WIND GUSTS TO 45 KTS WILL
OCCUR WITH THE STRONGER TSRA.  A FEW CLOUDS-SKC CONDITIONS EXPECTED
THRU MID MORNING WEST OF A KOLS TO KCGZ LINE...WITH SCT-BKN CLOUDS
AT 8-14K FT AGL EAST OF THIS LINE.  SCT-BKN CLOUDS AREAWIDE THIS
AFTERNOON AND EVENING AT 6-11K FT AGL...SLOWLY DIMINISHING AFT
21/04Z TONIGHT.  OUTSIDE OF THUNDERSTORM OUTFLOWS...SURFACE WIND
WILL GENERALLY BE LESS THAN 10 KTS.  AVIATION DISCUSSION NOT UPDATED
FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS ARE EXPECTED THROUGH EARLY NEXT WEEK.  OVERALL THROUGH
THE WEEKEND THERE WILL BE LESS ACTIVITY THAN WE HAVE HAD OVER THE
LAST WEEK AND THE STORMS WILL NOT BE AS HEAVY WITH RESPECT TO RAIN.
THAT SAID...ANY STRONGER THUNDERSTORMS WILL PRODUCE STRONG...GUSTY
AND ERRATIC WINDS.  OUTSIDE OF THE THUNDERSTORM OUTFLOWS...20-FOOT
WINDS WILL EXHIBIT NORMAL DIURNAL TRENDS AND WILL BE MOSTLY LESS
THAN 15 MPH.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON








000
FXUS65 KTWC 201531
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
830 AM MST WED AUG 20 2014

.SYNOPSIS...SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS
WILL CONTINUE THROUGH FRIDAY WITH SOME STORMS PRODUCING HEAVY RAIN
AND GUSTY WINDS.  GRADUAL DRYING IS EXPECTED TO OCCUR THIS WEEKEND
INTO EARLY NEXT WEEK...HOWEVER ENOUGH MOISTURE WILL REMAIN FOR
ISOLATED TO SCATTERED THUNDERSTORMS.  BELOW NORMAL DAYTIME
TEMPERATURES WILL PREVAIL THROUGH FRIDAY FOLLOWED BY A WARMING TREND
THIS WEEKEND.

&&

.DISCUSSION...OTHER THAN A FEW PATCHES OF CLOUDS FAR EASTERN
SECTIONS SKIES ARE CLEAR THIS MORNING.  THE SOUNDING THIS MORNING
SHOWS A SIGNIFICANTLY DRIER MID AND UPPER LEVEL ATMOSPHERE BUT STILL
RATHER UNSTABLE THANKS TO PLENTY OF LOW LEVEL MOISTURE.  THE LOW
LEVEL MOISTURE WILL MIX OUT TO SOME EXTENT BUT SHOULD BE ENOUGH FOR
A FEW THUNDERSTORMS TO DEVELOP OVER THE HIGHER TERRAIN TODAY.  CU
ALREADY SHOWING UP OVER THE HUACHUCA MTNS ALREADY.  ANY STORMS THAT
DEVELOP WILL MOVE OFF TO THE NORTHEAST AND BE YOUR MORE TYPICAL RAIN
AND WIND PRODUCERS RATHER THAN THE HEAVY RAINERS OF LATE.  AS FAR AS
HIGH TEMPERATURES...WILL HAVE RELATIVELY LOW THICKNESS VALUES ACROSS
THE REGION WHICH WILL HOLD HI TEMPS A FEW DEGREES COOLER THAN
NORMAL.  THE WESTERN DESERTS WILL HAVE SIMILAR TEMPS TO YESTERDAY
WHILE AREAS EAST OF TUCSON...WHILE STILL COOLER THAN NORMAL WILL BE
UP TO 10 DEGREES WARMER THAN YESTERDAY THANKS TO MORE SUNSHINE.  NO
UPDATES NEEDED AT THIS TIME.
CERNIGLIA

THE REMAINDER OF THIS SECTION IS FROM THE PRECIOUS DISCUSSION.

TONIGHT...MODEL CROSS SECTIONS INDICATE THAT A BIT MORE MID-LEVEL
MOISTURE WILL BE PULLED FROM THE OUTER EDGE OF TS LOWELL INTO SW AZ
AS THE CLOSED LOW OFF THE SOUTHERN CALIFORNIA COAST SLOWLY MOVES
INLAND OVER SAN DIEGO. COULD SEE A FEW STORMS DEVELOP OVER OUR
WESTERN DESERTS LATE TONIGHT INTO THURSDAY MORNING.

THURSDAY LOOKS RATHER ACTIVE AS THE CLOSED LOW OPENS UP AS IT MOVES
INTO WESTERN ARIZONA. THUS EXPECT A RETURN TO SCATTERED AFTERNOON
AND EVENING SHOWERS AND THUNDERSTORMS. HIGHS SIMILAR TO WHAT IS
FORECAST FOR TODAY WHICH CONTINUES TO BE BELOW NORMAL.

FRIDAY...TROF AXIS WILL BE MOVING INTO WESTERN NEW MEXICO WITH DRIER
AIR FILTERING ACROSS THE AREA FROM THE WEST. PRECIPITABLE WATER
VALUES ARE PROGGED TO BE LESS THAN ONE INCH IN THE WHITES TO NEAR
1.50" ALONG THE INTNL BORDER. THIS WILL LIMIT THUNDERSTORM ACTIVITY
TO THE MOUNTAINS EAST OF TUCSON AND ALONG THE INTERNATIONAL BORDER
FROM NOGALES EAST. BELOW NORMAL HIGHS CONTINUE FOR ONE MORE DAY.

SATURDAY...THE PACIFIC UPPER TROF THAT KICKS OUR CURRENT LOW THRU
THE STATE ON FRIDAY WILL BE PASSING BY TO OUR NORTH. RATHER DRY
WESTERLY FLOW ALOFT WITH PRECIPITABLE WATER VALUES PROGGED TO RANGE
FROM 0.75"-1.25" DRIEST IN THE WHITES. THUNDERSTORM COVERAGE LESS
THAN FRIDAY BUT PRETTY MUCH IN THE SAME AREAS. WARMER WITH HIGHS
EDGING CLOSER TO NORMAL.

SUNDAY...TROFINESS REMAINING TO OUR NORTH WILL LIMIT ANY
THUNDERSTORM ACTIVITY TO MAINLY THE HIGHER TERRAIN E AND S OF
TUCSON. HIGHS WILL BE AT OR SLIGHTLY ABOVE NORMAL.

MONDAY AND TUESDAY...WILL MAINTAIN LOW GRADE MONSOON FORECAST AS
UPPER LEVEL TROFINESS REMAINS CLOSE TO THE STATE.

DEEPER MOISTURE MAY RETURN TO THE AREA THANKS TO A TROPICAL SYSTEM
MOVING CLOSE ENOUGH TO THE GULF OF CA TO SEND A SURGE OF MOISTURE
NORTH INTO THE STATE. TIME WILL TELL.

&&

.AVIATION...VALID THRU 21/18Z.
EXPECT ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS THIS
AFTERNOON...PERSISTING INTO THE EARLY EVENING HOURS.  THESE WILL
MAINLY HUG THE MOUNTAINS WITH THE KOLS AND KDUG TERMINALS MOST
LIKELY TO BE AFFECTED.  KTUS WILL LIKELY NOT HAVE ANY THUNDERSTORM
ACTIVITY TODAY.  MVFR VISIBILITIES AND WIND GUSTS TO 45 KTS WILL
OCCUR WITH THE STRONGER TSRA.  A FEW CLOUDS-SKC CONDITIONS EXPECTED
THRU MID MORNING WEST OF A KOLS TO KCGZ LINE...WITH SCT-BKN CLOUDS
AT 8-14K FT AGL EAST OF THIS LINE.  SCT-BKN CLOUDS AREAWIDE THIS
AFTERNOON AND EVENING AT 6-11K FT AGL...SLOWLY DIMINISHING AFT
21/04Z TONIGHT.  OUTSIDE OF THUNDERSTORM OUTFLOWS...SURFACE WIND
WILL GENERALLY BE LESS THAN 10 KTS.  AVIATION DISCUSSION NOT UPDATED
FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS ARE EXPECTED THROUGH EARLY NEXT WEEK.  OVERALL THROUGH
THE WEEKEND THERE WILL BE LESS ACTIVITY THAN WE HAVE HAD OVER THE
LAST WEEK AND THE STORMS WILL NOT BE AS HEAVY WITH RESPECT TO RAIN.
THAT SAID...ANY STRONGER THUNDERSTORMS WILL PRODUCE STRONG...GUSTY
AND ERRATIC WINDS.  OUTSIDE OF THE THUNDERSTORM OUTFLOWS...20-FOOT
WINDS WILL EXHIBIT NORMAL DIURNAL TRENDS AND WILL BE MOSTLY LESS
THAN 15 MPH.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON







000
FXUS65 KTWC 201003
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
303 AM MST WED AUG 20 2014

.SYNOPSIS...SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS
WILL CONTINUE THROUGH FRIDAY. SOME STORMS WILL PRODUCE HEAVY
RAINFALL AND GUSTY WINDS. A GRADUAL DRYING IS EXPECTED TO OCCUR
THIS WEEKEND INTO EARLY NEXT WEEK. HOWEVER...ENOUGH MOISTURE WILL
REMAIN FOR ISOLATED TO SCATTERED THUNDERSTORMS. BELOW NORMAL DAYTIME
TEMPERATURES WILL PREVAIL THROUGH FRIDAY FOLLOWED BY A WARMING TREND
THIS WEEKEND.

&&

.DISCUSSION...DEBRIS CLOUDS CONTINUE ACROSS EASTERN HALF OF FORECAST
AREA WITH RADAR SHOWING LITTLE TO NO ACTIVITY WITH THESE CLOUDS.
WATER VAPOR IMAGERY PLACED CLOSED UPPER LOW OFF SRN CA CST WITH MUCH
DRIER AIR OVER MOST OF THE STATE VERSUS 24 HOURS AGO. THIS LOW HAS
STARTED TO TAP INTO MAINLY HIGH LEVEL MOISTURE FROM THE OUTER EDGE
OF TROPICAL STORM LOWELL...WHICH AS OF THE LATEST ADVISORY WAS
LOCATED 775 MILES WSW OF THE BAJA CALIFORNIA TIP. AS FOR THE CLOSED
UPPER LOW...MODELS ARE IN PRETTY GOOD AGREEMENT ON MEANDERING IT
NEAR THE SRN CA CST TODAY. ALTHOUGH MOISTURE VALUES ARE STILL
RELATIVELY HIGH...THE DRIER SW FLOW ALOFT ALONG WITH A COOL BOUNDARY
LAYER WILL LIMIT THUNDERSTORMS TODAY MOSTLY TO THE HIGHER TERRAIN.
CAN`T RULE OUT A FEW GETTING INTO THE VALLEYS. HAVE THUS LOWERED
POPS ACROSS THE BOARD TODAY WITH VALUES CLOSE TO MOS GUIDANCE. HIGHS
TODAY FROM TUCSON WEST WILL BE NEAR TUESDAY HIGHS WHILE AREAS TO THE
EAST WILL BE MUCH WARMER VERSUS RATHER CLOUDY/SHOWERY TUESDAY.

TONIGHT...MODEL CROSS SECTIONS INDICATE THAT A BIT MORE MID-LEVEL
MOISTURE WILL BE PULL FROM THE OUTER EDGE OF TS LOWELL INTO SW AZ AS
THE CLOSED LOW SLOWLY MOVES INLAND OVER SAN DIEGO. COULD SEE A FEW
STORMS DEVELOP OVER OUR WESTERN DESERTS LATE TONIGHT INTO THURSDAY
MORNING.

THURSDAY LOOKS AT RATHER ACTIVE AS CLOSED LOW OPENS UP AS IT MOVES
INTO WESTERN ARIZONA. THUS EXPECT A RETURN TO SCATTERED AFTERNOON
AND EVENING SHOWERS AND THUNDERSTORMS. HIGHS SIMILAR TO WHAT IS
FORECAST FOR TODAY WHICH CONTINUES TO BE BELOW NORMAL.

FRIDAY...TROF AXIS WILL BE MOVING INTO WESTERN NEW MEXICO WITH DRIER
AIR FILTERING ACROSS THE AREA FROM THE WEST. PRECIPITABLE WATER
VALUES ARE PROGGED TO BE LESS THAN ONE INCH IN THE WHITES TO NEAR
1.50" ALONG THE INTNL BORDER. THIS WILL LIMIT THUNDERSTORM ACTIVITY
TO THE MOUNTAINS EAST OF TUCSON AND ALONG THE INTERNATIONAL BORDER
FROM NOGALES EAST. BELOW NORMAL HIGHS CONTINUE FOR ONE MORE DAY.

SATURDAY...THE PACIFIC UPPER TROF THAT KICKS OUR CURRENT LOW THRU
THE STATE ON FRIDAY WILL BE PASSING BY TO OUR NORTH. RATHER DRY
WESTERLY FLOW ALOFT WITH PRECIPITABLE WATER VALUES PROGGED TO RANGE
FROM 0.75"-1.25" DRIEST IN THE WHITES. THUNDERSTORM COVERAGE LESS
THAN FRIDAY BUT PRETTY MUCH IN THE SAME AREAS. WARMER WITH HIGHS
EDGING CLOSER TO NORMAL.

SUNDAY...TROFINESS REMAINING TO OUR NORTH WILL LIMIT ANY
THUNDERSTORM ACTIVITY TO MAINLY THE HIGHER TERRAIN E AND S OF
TUCSON. HIGHS WILL BE AT OR SLIGHTLY ABOVE NORMAL.

MONDAY AND TUESDAY...WILL MAINTAIN LOW GRADE MONSOON FORECAST AS
UPPER LEVEL TROFINESS REMAINS CLOSE TO THE STATE.

DEEPER MOISTURE MAY RETURN TO THE AREA THANKS TO A TROPICAL SYSTEM
MOVING CLOSE ENOUGH TO THE GULF OF CA TO SEND A SURGE OF MOISTURE
NORTH INTO THE STATE. TIME WILL TELL.

&&

.AVIATION...VALID THRU 21/12Z.
EXPECT ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING
THIS AFTERNOON...PERSISTING INTO THE EVENING HOURS TONIGHT. MVFR
VISIBILITIES AND WIND GUSTS TO 45 KTS WILL OCCUR WITH THE STRONGER
TSRA. A FEW CLOUDS-SKC CONDITIONS EXPECTED THRU MID MORNING WEST OF
A KOLS TO KCGZ LINE...WITH SCT-BKN CLOUDS AT 8-14K FT AGL EAST OF
THIS LINE. SCT-BKN CLOUDS AREAWIDE THIS AFTERNOON AND EVENING AT
6-11K FT AGL...SLOWLY DIMINISHING AFT 21/04Z TONIGHT. OUTSIDE OF
THUNDERSTORM OUTFLOWS...SURFACE WIND WILL GENERALLY BE LESS THAN 10
KTS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS ARE EXPECTED THROUGH EARLY NEXT WEEK. THE STRONGER
THUNDERSTORMS WILL PRODUCE STRONG...GUSTY AND ERRATIC WINDS. OUTSIDE
OF THE THUNDERSTORM OUTFLOWS...20-FOOT WINDS WILL EXHIBIT NORMAL
DIURNAL TRENDS AND WILL BE MOSTLY LESS THAN 15 MPH.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON








000
FXUS65 KTWC 201003
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
303 AM MST WED AUG 20 2014

.SYNOPSIS...SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS
WILL CONTINUE THROUGH FRIDAY. SOME STORMS WILL PRODUCE HEAVY
RAINFALL AND GUSTY WINDS. A GRADUAL DRYING IS EXPECTED TO OCCUR
THIS WEEKEND INTO EARLY NEXT WEEK. HOWEVER...ENOUGH MOISTURE WILL
REMAIN FOR ISOLATED TO SCATTERED THUNDERSTORMS. BELOW NORMAL DAYTIME
TEMPERATURES WILL PREVAIL THROUGH FRIDAY FOLLOWED BY A WARMING TREND
THIS WEEKEND.

&&

.DISCUSSION...DEBRIS CLOUDS CONTINUE ACROSS EASTERN HALF OF FORECAST
AREA WITH RADAR SHOWING LITTLE TO NO ACTIVITY WITH THESE CLOUDS.
WATER VAPOR IMAGERY PLACED CLOSED UPPER LOW OFF SRN CA CST WITH MUCH
DRIER AIR OVER MOST OF THE STATE VERSUS 24 HOURS AGO. THIS LOW HAS
STARTED TO TAP INTO MAINLY HIGH LEVEL MOISTURE FROM THE OUTER EDGE
OF TROPICAL STORM LOWELL...WHICH AS OF THE LATEST ADVISORY WAS
LOCATED 775 MILES WSW OF THE BAJA CALIFORNIA TIP. AS FOR THE CLOSED
UPPER LOW...MODELS ARE IN PRETTY GOOD AGREEMENT ON MEANDERING IT
NEAR THE SRN CA CST TODAY. ALTHOUGH MOISTURE VALUES ARE STILL
RELATIVELY HIGH...THE DRIER SW FLOW ALOFT ALONG WITH A COOL BOUNDARY
LAYER WILL LIMIT THUNDERSTORMS TODAY MOSTLY TO THE HIGHER TERRAIN.
CAN`T RULE OUT A FEW GETTING INTO THE VALLEYS. HAVE THUS LOWERED
POPS ACROSS THE BOARD TODAY WITH VALUES CLOSE TO MOS GUIDANCE. HIGHS
TODAY FROM TUCSON WEST WILL BE NEAR TUESDAY HIGHS WHILE AREAS TO THE
EAST WILL BE MUCH WARMER VERSUS RATHER CLOUDY/SHOWERY TUESDAY.

TONIGHT...MODEL CROSS SECTIONS INDICATE THAT A BIT MORE MID-LEVEL
MOISTURE WILL BE PULL FROM THE OUTER EDGE OF TS LOWELL INTO SW AZ AS
THE CLOSED LOW SLOWLY MOVES INLAND OVER SAN DIEGO. COULD SEE A FEW
STORMS DEVELOP OVER OUR WESTERN DESERTS LATE TONIGHT INTO THURSDAY
MORNING.

THURSDAY LOOKS AT RATHER ACTIVE AS CLOSED LOW OPENS UP AS IT MOVES
INTO WESTERN ARIZONA. THUS EXPECT A RETURN TO SCATTERED AFTERNOON
AND EVENING SHOWERS AND THUNDERSTORMS. HIGHS SIMILAR TO WHAT IS
FORECAST FOR TODAY WHICH CONTINUES TO BE BELOW NORMAL.

FRIDAY...TROF AXIS WILL BE MOVING INTO WESTERN NEW MEXICO WITH DRIER
AIR FILTERING ACROSS THE AREA FROM THE WEST. PRECIPITABLE WATER
VALUES ARE PROGGED TO BE LESS THAN ONE INCH IN THE WHITES TO NEAR
1.50" ALONG THE INTNL BORDER. THIS WILL LIMIT THUNDERSTORM ACTIVITY
TO THE MOUNTAINS EAST OF TUCSON AND ALONG THE INTERNATIONAL BORDER
FROM NOGALES EAST. BELOW NORMAL HIGHS CONTINUE FOR ONE MORE DAY.

SATURDAY...THE PACIFIC UPPER TROF THAT KICKS OUR CURRENT LOW THRU
THE STATE ON FRIDAY WILL BE PASSING BY TO OUR NORTH. RATHER DRY
WESTERLY FLOW ALOFT WITH PRECIPITABLE WATER VALUES PROGGED TO RANGE
FROM 0.75"-1.25" DRIEST IN THE WHITES. THUNDERSTORM COVERAGE LESS
THAN FRIDAY BUT PRETTY MUCH IN THE SAME AREAS. WARMER WITH HIGHS
EDGING CLOSER TO NORMAL.

SUNDAY...TROFINESS REMAINING TO OUR NORTH WILL LIMIT ANY
THUNDERSTORM ACTIVITY TO MAINLY THE HIGHER TERRAIN E AND S OF
TUCSON. HIGHS WILL BE AT OR SLIGHTLY ABOVE NORMAL.

MONDAY AND TUESDAY...WILL MAINTAIN LOW GRADE MONSOON FORECAST AS
UPPER LEVEL TROFINESS REMAINS CLOSE TO THE STATE.

DEEPER MOISTURE MAY RETURN TO THE AREA THANKS TO A TROPICAL SYSTEM
MOVING CLOSE ENOUGH TO THE GULF OF CA TO SEND A SURGE OF MOISTURE
NORTH INTO THE STATE. TIME WILL TELL.

&&

.AVIATION...VALID THRU 21/12Z.
EXPECT ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING
THIS AFTERNOON...PERSISTING INTO THE EVENING HOURS TONIGHT. MVFR
VISIBILITIES AND WIND GUSTS TO 45 KTS WILL OCCUR WITH THE STRONGER
TSRA. A FEW CLOUDS-SKC CONDITIONS EXPECTED THRU MID MORNING WEST OF
A KOLS TO KCGZ LINE...WITH SCT-BKN CLOUDS AT 8-14K FT AGL EAST OF
THIS LINE. SCT-BKN CLOUDS AREAWIDE THIS AFTERNOON AND EVENING AT
6-11K FT AGL...SLOWLY DIMINISHING AFT 21/04Z TONIGHT. OUTSIDE OF
THUNDERSTORM OUTFLOWS...SURFACE WIND WILL GENERALLY BE LESS THAN 10
KTS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS ARE EXPECTED THROUGH EARLY NEXT WEEK. THE STRONGER
THUNDERSTORMS WILL PRODUCE STRONG...GUSTY AND ERRATIC WINDS. OUTSIDE
OF THE THUNDERSTORM OUTFLOWS...20-FOOT WINDS WILL EXHIBIT NORMAL
DIURNAL TRENDS AND WILL BE MOSTLY LESS THAN 15 MPH.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON







000
FXUS65 KTWC 200425
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
925 PM MST TUE AUG 19 2014

.SYNOPSIS...SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS
WILL CONTINUE THROUGH FRIDAY. SOME STORMS WILL PRODUCE HEAVY
RAINFALL AND GUSTY WINDS. A GRADUAL DRYING IS EXPECTED TO OCCUR
THIS WEEKEND INTO EARLY NEXT WEEK. HOWEVER...ENOUGH MOISTURE WILL
REMAIN FOR ISOLATED TO SCATTERED THUNDERSTORMS. BELOW NORMAL DAYTIME
TEMPERATURES WILL PREVAIL THROUGH FRIDAY FOLLOWED BY A WARMING TREND
THIS WEEKEND.

&&

.DISCUSSION...KEMX WSR-88D DETECTED SCATTERED 30-45 DBZ ECHOES
ACROSS FAR ERN PIMA/NWRN COCHISE/NERN SANTA CRUZ COUNTIES AT 0420Z.
OTHER ISOLATED 30-45 DBZ ECHOES WERE ACROSS SOUTH CENTRAL PINAL
COUNTY. THE REST OF SE AZ WAS VOID OF PRECIP ECHOES AT THIS TIME.
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS HAVE DIMINISHED
CONSIDERABLY IN INTENSITY DURING THE PAST HOUR ACROSS EAST CENTRAL
PIMA COUNTY.

THUS...THE FLASH FLOOD WARNING WAS REPLACED WITH A SMALL STREAM
FLOOD ADVISORY UNTIL 1030 PM MST. ALSO...THE FLASH FLOOD WATCH HAS
BEEN LIMITED TO ESSENTIALLY COCHISE COUNTY...AND REMAINS IN EFFECT
UNTIL 11 PM MST. THE FAVORED LOCALES FOR ANY RAINFALL OF
SIGNIFICANCE SHOULD BE ACROSS COCHISE COUNTY UNTIL AROUND MIDNIGHT
OR SO...AS PER RADAR TRENDS AND THE 20/00Z NAM.

FOR THE REST OF TONIGHT...HAVE MAINTAINED A SLIGHT CHANCE OF SHOWERS
AND THUNDERSTORMS ESSENTIALLY FROM TUCSON EWD TO THE NEW MEXICO
BORDER. MOSTLY CLEAR SKIES SHOULD PREVAIL ACROSS WRN PIMA COUNTY.

PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.

&&

.AVIATION...VALID THRU 21/06Z.
EXPECT SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS SOUTH TO
SOUTHEAST OF KTUS UNTIL AROUND 20/06Z FOLLOWED BY ISOLATED COVERAGE
OF -TSRA/-SHRA MAINLY NEAR THE NEW MEXICO BORDER LATE TONIGHT INTO
WEDNESDAY MORNING. ISOLATED TO SCATTERED TSRA/SHRA WILL OCCUR
WEDNESDAY AFTERNOON AND WEDNESDAY EVENING. MVFR VISIBILITIES AND
WIND GUSTS OF 35-45 KTS WILL OCCUR WITH THE STRONGER TSRA.
OTHERWISE...CLOUD DECKS WILL MAINLY BE AT 6-12K FT AGL AND SURFACE
WIND WILL GENERALLY BE LESS THAN 10 KTS THRU WEDNESDAY EVENING.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...EXPECT SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS THROUGH FRIDAY. SOMEWHAT LESS COVERAGE OF
THUNDERSTORMS IS FORECAST TO OCCUR THIS WEEKEND AND EARLY NEXT WEEK.
ENOUGH MOISTURE WILL CONTINUE FOR ISOLATED TO SCATTERED MAINLY
AFTERNOON AND EVENING THUNDERSTORMS. OTHERWISE...20-FOOT WINDS WILL
EXHIBIT NORMAL DIURNAL TRENDS AND WILL BE MOSTLY LESS THAN 15 MPH.

&&

.PREV DISCUSSION...AS THE UPPER LOW CONTINUES TO APPROACH THE REGION
IT WILL PUSH SOME DRIER AIR IN OVERNIGHT FROM THE WEST BEHIND THE
MAIN AREA OF SHOWERS AND THUNDERSTORMS WHICH WILL RESULT IN A
DECREASE IN THE CONVECTION ACROSS THE REGION FROM WEST TO EAST. AS A
RESULT OF THE DRIER AIR MOVING IN ALOFT AND LIMITED FORCING...THERE
WILL BE LESS AREAL COVERAGE OF STORMS ON WEDNESDAY...BUT THANKS TO
PLENTY OF NEAR SURFACE MOISTURE IT SHOULD REMAIN SOMEWHAT ACTIVE.
LIKELY SIMILAR TO A TYPICAL AVERAGE MONSOON DAY WITH CONVECTION
FIRING OFF THE HIGHER TERRAIN AND DRIFTING TO THE NORTH-NORTHEAST.

BEYOND THAT THE OPERATIONAL MODELS ARE COMING IN LINE WITH THE UPPER
LOW OVER SOUTHERN CALIFORNIA...AT LEAST MORE IN LINE. THE GFS IS
STILL THE SLOWER MODEL BUT ITS COMING AROUND TO THE OTHER SOLUTIONS.
WITH THE IDEA OF LEANING SLOWER...THE LOW WOULD LIFT NE THROUGH
CENTRAL AND/OR NORTHERN ARIZONA THURSDAY NIGHT INTO EARLY FRIDAY.
THIS COULD MAKE FOR AN INTERESTING THURSDAY AFTERNOON AND EVENING.
I TWEAKED POPS UP A BIT THAT TIME FRAME BUT THEY MAY END UP HIGHER
YET FOR THAT TIME PERIOD. BELOW NORMAL HIGH TEMPERATURES EXPECTED
THROUGH AT LEAST THURSDAY THANKS TO THE ENHANCED CONVECTION.

DRIER AIR MOVES INTO NORTHERN AREAS FRIDAY ONWARD WITH DEEP MOISTURE
HANGING NEAR THE INTERNATIONAL BORDER AND SOUTH OF THERE AS WESTERLY
FLOW DEVELOPS OVER THE STATE. WITH THAT THOUGHT WILL LIKELY HAVE A
DECENT DOWNTURN IN THE CONVECTION OVER THE REGION WITH THE POSSIBLE
EXCEPTION OF ALONG THE BORDER AREA. THE RELATIVE LACK OF CONVECTION
WILL ALLOW AFTERNOON TEMPERATURES TO RETURN TO NORMAL LEVELS ACROSS
THE REGION SATURDAY ONWARD.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
   FLASH FLOOD WATCH UNTIL 11 PM MST THIS EVENING FOR AZZ507-508-
   512-513.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

FRANCIS
PREVIOUS DISCUSSION...CERNIGLIA






000
FXUS65 KTWC 200425
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
925 PM MST TUE AUG 19 2014

.SYNOPSIS...SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS
WILL CONTINUE THROUGH FRIDAY. SOME STORMS WILL PRODUCE HEAVY
RAINFALL AND GUSTY WINDS. A GRADUAL DRYING IS EXPECTED TO OCCUR
THIS WEEKEND INTO EARLY NEXT WEEK. HOWEVER...ENOUGH MOISTURE WILL
REMAIN FOR ISOLATED TO SCATTERED THUNDERSTORMS. BELOW NORMAL DAYTIME
TEMPERATURES WILL PREVAIL THROUGH FRIDAY FOLLOWED BY A WARMING TREND
THIS WEEKEND.

&&

.DISCUSSION...KEMX WSR-88D DETECTED SCATTERED 30-45 DBZ ECHOES
ACROSS FAR ERN PIMA/NWRN COCHISE/NERN SANTA CRUZ COUNTIES AT 0420Z.
OTHER ISOLATED 30-45 DBZ ECHOES WERE ACROSS SOUTH CENTRAL PINAL
COUNTY. THE REST OF SE AZ WAS VOID OF PRECIP ECHOES AT THIS TIME.
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS HAVE DIMINISHED
CONSIDERABLY IN INTENSITY DURING THE PAST HOUR ACROSS EAST CENTRAL
PIMA COUNTY.

THUS...THE FLASH FLOOD WARNING WAS REPLACED WITH A SMALL STREAM
FLOOD ADVISORY UNTIL 1030 PM MST. ALSO...THE FLASH FLOOD WATCH HAS
BEEN LIMITED TO ESSENTIALLY COCHISE COUNTY...AND REMAINS IN EFFECT
UNTIL 11 PM MST. THE FAVORED LOCALES FOR ANY RAINFALL OF
SIGNIFICANCE SHOULD BE ACROSS COCHISE COUNTY UNTIL AROUND MIDNIGHT
OR SO...AS PER RADAR TRENDS AND THE 20/00Z NAM.

FOR THE REST OF TONIGHT...HAVE MAINTAINED A SLIGHT CHANCE OF SHOWERS
AND THUNDERSTORMS ESSENTIALLY FROM TUCSON EWD TO THE NEW MEXICO
BORDER. MOSTLY CLEAR SKIES SHOULD PREVAIL ACROSS WRN PIMA COUNTY.

PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.

&&

.AVIATION...VALID THRU 21/06Z.
EXPECT SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS SOUTH TO
SOUTHEAST OF KTUS UNTIL AROUND 20/06Z FOLLOWED BY ISOLATED COVERAGE
OF -TSRA/-SHRA MAINLY NEAR THE NEW MEXICO BORDER LATE TONIGHT INTO
WEDNESDAY MORNING. ISOLATED TO SCATTERED TSRA/SHRA WILL OCCUR
WEDNESDAY AFTERNOON AND WEDNESDAY EVENING. MVFR VISIBILITIES AND
WIND GUSTS OF 35-45 KTS WILL OCCUR WITH THE STRONGER TSRA.
OTHERWISE...CLOUD DECKS WILL MAINLY BE AT 6-12K FT AGL AND SURFACE
WIND WILL GENERALLY BE LESS THAN 10 KTS THRU WEDNESDAY EVENING.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...EXPECT SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS THROUGH FRIDAY. SOMEWHAT LESS COVERAGE OF
THUNDERSTORMS IS FORECAST TO OCCUR THIS WEEKEND AND EARLY NEXT WEEK.
ENOUGH MOISTURE WILL CONTINUE FOR ISOLATED TO SCATTERED MAINLY
AFTERNOON AND EVENING THUNDERSTORMS. OTHERWISE...20-FOOT WINDS WILL
EXHIBIT NORMAL DIURNAL TRENDS AND WILL BE MOSTLY LESS THAN 15 MPH.

&&

.PREV DISCUSSION...AS THE UPPER LOW CONTINUES TO APPROACH THE REGION
IT WILL PUSH SOME DRIER AIR IN OVERNIGHT FROM THE WEST BEHIND THE
MAIN AREA OF SHOWERS AND THUNDERSTORMS WHICH WILL RESULT IN A
DECREASE IN THE CONVECTION ACROSS THE REGION FROM WEST TO EAST. AS A
RESULT OF THE DRIER AIR MOVING IN ALOFT AND LIMITED FORCING...THERE
WILL BE LESS AREAL COVERAGE OF STORMS ON WEDNESDAY...BUT THANKS TO
PLENTY OF NEAR SURFACE MOISTURE IT SHOULD REMAIN SOMEWHAT ACTIVE.
LIKELY SIMILAR TO A TYPICAL AVERAGE MONSOON DAY WITH CONVECTION
FIRING OFF THE HIGHER TERRAIN AND DRIFTING TO THE NORTH-NORTHEAST.

BEYOND THAT THE OPERATIONAL MODELS ARE COMING IN LINE WITH THE UPPER
LOW OVER SOUTHERN CALIFORNIA...AT LEAST MORE IN LINE. THE GFS IS
STILL THE SLOWER MODEL BUT ITS COMING AROUND TO THE OTHER SOLUTIONS.
WITH THE IDEA OF LEANING SLOWER...THE LOW WOULD LIFT NE THROUGH
CENTRAL AND/OR NORTHERN ARIZONA THURSDAY NIGHT INTO EARLY FRIDAY.
THIS COULD MAKE FOR AN INTERESTING THURSDAY AFTERNOON AND EVENING.
I TWEAKED POPS UP A BIT THAT TIME FRAME BUT THEY MAY END UP HIGHER
YET FOR THAT TIME PERIOD. BELOW NORMAL HIGH TEMPERATURES EXPECTED
THROUGH AT LEAST THURSDAY THANKS TO THE ENHANCED CONVECTION.

DRIER AIR MOVES INTO NORTHERN AREAS FRIDAY ONWARD WITH DEEP MOISTURE
HANGING NEAR THE INTERNATIONAL BORDER AND SOUTH OF THERE AS WESTERLY
FLOW DEVELOPS OVER THE STATE. WITH THAT THOUGHT WILL LIKELY HAVE A
DECENT DOWNTURN IN THE CONVECTION OVER THE REGION WITH THE POSSIBLE
EXCEPTION OF ALONG THE BORDER AREA. THE RELATIVE LACK OF CONVECTION
WILL ALLOW AFTERNOON TEMPERATURES TO RETURN TO NORMAL LEVELS ACROSS
THE REGION SATURDAY ONWARD.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
   FLASH FLOOD WATCH UNTIL 11 PM MST THIS EVENING FOR AZZ507-508-
   512-513.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

FRANCIS
PREVIOUS DISCUSSION...CERNIGLIA







000
FXUS65 KTWC 192106
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
200 PM MST TUE AUG 19 2014

.SYNOPSIS...ABUNDANT MOISTURE COMBINED WITH AN APPROACHING UPPER LOW
WILL CONTINUE TO GENERATE NUMEROUS SHOWERS AND THUNDERSTORMS INTO
THE EVENING HOURS FROM TUCSON EASTWARD WITH LOCAL VERY HEAVY
RAINFALL.  A SLIGHTLY DRIER ATMOSPHERE AND LESS FORCING WILL ALLOW
FOR A MORE TYPICAL AMOUNT OF CONVECTION THE REMAINDER OF THE WEEK
WITH A VERY MODEST DRYING TREND INTO THIS WEEKEND.  BELOW NORMAL
DAYTIME TEMPERATURES WILL PREVAIL THROUGH THURSDAY FOLLOWED BY A
GRADUAL WARMING TREND LATER THIS WEEK.

&&

.DISCUSSION...THE UPPER LOW CONTINUES TO GRADUALLY APPROACH WITH
THE ASSOCIATED DYNAMICS HAVING MORE INFLUENCE OVER THE AREA.  THIS
WILL CONTINUE TO BE THE CASE INTO THE EVENING HOURS WITH A MOIST AND
UNSTABLE AIR MASS IN PLACE.  DRIER AIR IN THE MID LEVELS IS PUNCHING
INTO THE WESTERN PORTIONS OF THE AREA AND HAS LIMITED CONVECTION
THERE.  THE PRIMARY CONCERN WILL BE FOR THE TUCSON AREA EAST TO THE
NEW MEXICO BORDER THIS EVENING.

CONVERGENT STREAMERS HAVE DEVELOPED ON SATELLITE IMAGERY AND ON THE
DOPPLER RADAR JUST WEST OF TUCSON AND AIMED AT THE CITY WHERE
CONVECTION CONTINUES TO BLOSSOM OVER THE CITY WITH PERIODS OF HEAVY
RAIN.  PLENTY OF STANDING AND FLOWING WATER WITH AREA WASHES
RISING.  VARIOUS HI RES MODELS ALL POINT TO CONTINUED DEVELOPMENT
OVER/AROUND THE CITY THROUGH 7-8 PM THIS EVENING AND THIS WILL HAVE
TO BE WATCHED CLOSELY...ESPECIALLY WITH RESPECT TO HEAVY RAIN IN THE
CATALINAS AND RINCONS.  CURRENTLY HAVE AN URBAN AND SMALL STREAM
ADVISORY IN EFFECT FOR THE IMMEDIATE AREA.

PLENTY OF SHOWER ACTIVITY OVER COCHISE AND EASTERN PINAL COUNTIES AS
WELL WITH A FEW RURAL ROADS CLOSED DUE TO HIGH WATER.  THIS WILL
NEED TO WATCHED WELL INTO THE EVENING AS SHOWER ACTIVITY LIKELY TO
CONTINUE OVER EASTERN AREAS WELL INTO THE EVENING.

AS THE UPPER LOW CONTINUES TO APPROACH THE REGION IT WILL PUSH SOME
DRIER AIR IN OVERNIGHT FROM THE WEST BEHIND THE MAIN AREA OF SHOWERS
AND THUNDERSTORMS WHICH WILL RESULT IN A DECREASE IN THE CONVECTION
ACROSS THE REGION FROM WEST TO EAST.  AS A RESULT OF THE DRIER AIR
MOVING IN ALOFT AND LIMITED FORCING...THERE WILL BE LESS AREAL
COVERAGE OF STORMS ON WEDNESDAY...BUT THANKS TO PLENTY OF NEAR
SURFACE MOISTURE IT SHOULD REMAIN SOMEWHAT ACTIVE.  LIKELY SIMILAR
TO A TYPICAL AVERAGE MONSOON DAY WITH CONVECTION FIRING OFF THE
HIGHER TERRAIN AND DRIFTING TO THE NORTH-NORTHEAST.

BEYOND THAT THE OPERATIONAL MODELS ARE COMING IN LINE WITH THE UPPER
LOW OVER SOUTHERN CALIFORNIA...AT LEAST MORE IN LINE.  THE GFS IS
STILL THE SLOWER MODEL BUT ITS COMING AROUND TO THE OTHER SOLUTIONS.
WITH THE IDEA OF LEANING SLOWER...THE LOW WOULD LIFT NE THROUGH
CENTRAL AND/OR NORTHERN ARIZONA THURSDAY NIGHT INTO EARLY FRIDAY.
THIS COULD MAKE FOR AN INTERESTING THURSDAY AFTERNOON AND EVENING.
I TWEAKED POPS UP A BIT THAT TIME FRAME BUT THEY MAY END UP HIGHER
YET FOR THAT TIME PERIOD.  BELOW NORMAL HIGH TEMPERATURES EXPECTED
THROUGH AT LEAST THURSDAY THANKS TO THE ENHANCED CONVECTION.

DRIER AIR MOVES INTO NORTHERN AREAS FRIDAY ONWARD WITH DEEP MOISTURE
HANGING NEAR THE INTERNATIONAL BORDER AND SOUTH OF THERE AS WESTERLY
FLOW DEVELOPS OVER THE STATE.  WITH THAT THOUGHT WILL LIKELY HAVE A
DECENT DOWNTURN IN THE CONVECTION OVER THE REGION WITH THE POSSIBLE
EXCEPTION OF ALONG THE BORDER AREA.  THE RELATIVE LACK OF CONVECTION
WILL ALLOW AFTERNOON TEMPERATURES TO RETURN TO NORMAL LEVELS ACROSS
THE REGION SATURDAY ONWARD.  CERNIGLIA

&&

.AVIATION...VALID THRU 21/00Z.
EXPECT SCATTERED TO NUMEROUS SHOWERS PERSISTING INTO TONIGHT...WITH
COVERAGE LESSENING OVERNIGHT. MVFR VISIBILITIES AND WIND GUSTS OF
45-50 KTS WILL OCCUR WITH THE STRONGER TSRA. CLOUD DECKS WILL MAINLY
BE AT 6-12K FT AGL. OUTSIDE OF THUNDERSTORM OUTFLOWS...SURFACE WIND
WILL GENERALLY BE LESS THAN 10 KTS. SCATTERED THUNDERSTORMS AND
SHOWERS POSSIBLE AGAIN STARTING LATE MORNING WEDNESDAY. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&

.FIRE WEATHER...SCATTERED TO NUMEROUS THUNDERSTORMS WILL CONTINUE
INTO TONIGHT AND START AGAIN LATE MORNING WEDNESDAY...AS AMPLE
MOISTURE REMAINS IN PLACE ACROSS SOUTHEASTERN ARIZONA. THE STRONGER
THUNDERSTORMS WILL PRODUCE HEAVY RAINFALL LEADING TO THE POSSIBILITY
OF LOCALIZED FLOODING...AS WELL AS STRONG...GUSTY AND ERRATIC WINDS.
EXPECT SOMEWHAT LESS COVERAGE OF THUNDERSTORMS DURING THE LATTER
PART OF THE WEEK AND NEXT WEEK. HOWEVER...MOISTURE WILL BE
SUFFICIENT FOR ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS. OUTSIDE OF THE THUNDERSTORM OUTFLOWS...20-FOOT WINDS
WILL EXHIBIT NORMAL DIURNAL TRENDS AND WILL BE MOSTLY LESS THAN 15
MPH.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
 FLASH FLOOD WATCH TODAY FROM 12 NOON UNTIL 11 PM FOR MOST OF SE AZ.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON







000
FXUS65 KTWC 192106
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
200 PM MST TUE AUG 19 2014

.SYNOPSIS...ABUNDANT MOISTURE COMBINED WITH AN APPROACHING UPPER LOW
WILL CONTINUE TO GENERATE NUMEROUS SHOWERS AND THUNDERSTORMS INTO
THE EVENING HOURS FROM TUCSON EASTWARD WITH LOCAL VERY HEAVY
RAINFALL.  A SLIGHTLY DRIER ATMOSPHERE AND LESS FORCING WILL ALLOW
FOR A MORE TYPICAL AMOUNT OF CONVECTION THE REMAINDER OF THE WEEK
WITH A VERY MODEST DRYING TREND INTO THIS WEEKEND.  BELOW NORMAL
DAYTIME TEMPERATURES WILL PREVAIL THROUGH THURSDAY FOLLOWED BY A
GRADUAL WARMING TREND LATER THIS WEEK.

&&

.DISCUSSION...THE UPPER LOW CONTINUES TO GRADUALLY APPROACH WITH
THE ASSOCIATED DYNAMICS HAVING MORE INFLUENCE OVER THE AREA.  THIS
WILL CONTINUE TO BE THE CASE INTO THE EVENING HOURS WITH A MOIST AND
UNSTABLE AIR MASS IN PLACE.  DRIER AIR IN THE MID LEVELS IS PUNCHING
INTO THE WESTERN PORTIONS OF THE AREA AND HAS LIMITED CONVECTION
THERE.  THE PRIMARY CONCERN WILL BE FOR THE TUCSON AREA EAST TO THE
NEW MEXICO BORDER THIS EVENING.

CONVERGENT STREAMERS HAVE DEVELOPED ON SATELLITE IMAGERY AND ON THE
DOPPLER RADAR JUST WEST OF TUCSON AND AIMED AT THE CITY WHERE
CONVECTION CONTINUES TO BLOSSOM OVER THE CITY WITH PERIODS OF HEAVY
RAIN.  PLENTY OF STANDING AND FLOWING WATER WITH AREA WASHES
RISING.  VARIOUS HI RES MODELS ALL POINT TO CONTINUED DEVELOPMENT
OVER/AROUND THE CITY THROUGH 7-8 PM THIS EVENING AND THIS WILL HAVE
TO BE WATCHED CLOSELY...ESPECIALLY WITH RESPECT TO HEAVY RAIN IN THE
CATALINAS AND RINCONS.  CURRENTLY HAVE AN URBAN AND SMALL STREAM
ADVISORY IN EFFECT FOR THE IMMEDIATE AREA.

PLENTY OF SHOWER ACTIVITY OVER COCHISE AND EASTERN PINAL COUNTIES AS
WELL WITH A FEW RURAL ROADS CLOSED DUE TO HIGH WATER.  THIS WILL
NEED TO WATCHED WELL INTO THE EVENING AS SHOWER ACTIVITY LIKELY TO
CONTINUE OVER EASTERN AREAS WELL INTO THE EVENING.

AS THE UPPER LOW CONTINUES TO APPROACH THE REGION IT WILL PUSH SOME
DRIER AIR IN OVERNIGHT FROM THE WEST BEHIND THE MAIN AREA OF SHOWERS
AND THUNDERSTORMS WHICH WILL RESULT IN A DECREASE IN THE CONVECTION
ACROSS THE REGION FROM WEST TO EAST.  AS A RESULT OF THE DRIER AIR
MOVING IN ALOFT AND LIMITED FORCING...THERE WILL BE LESS AREAL
COVERAGE OF STORMS ON WEDNESDAY...BUT THANKS TO PLENTY OF NEAR
SURFACE MOISTURE IT SHOULD REMAIN SOMEWHAT ACTIVE.  LIKELY SIMILAR
TO A TYPICAL AVERAGE MONSOON DAY WITH CONVECTION FIRING OFF THE
HIGHER TERRAIN AND DRIFTING TO THE NORTH-NORTHEAST.

BEYOND THAT THE OPERATIONAL MODELS ARE COMING IN LINE WITH THE UPPER
LOW OVER SOUTHERN CALIFORNIA...AT LEAST MORE IN LINE.  THE GFS IS
STILL THE SLOWER MODEL BUT ITS COMING AROUND TO THE OTHER SOLUTIONS.
WITH THE IDEA OF LEANING SLOWER...THE LOW WOULD LIFT NE THROUGH
CENTRAL AND/OR NORTHERN ARIZONA THURSDAY NIGHT INTO EARLY FRIDAY.
THIS COULD MAKE FOR AN INTERESTING THURSDAY AFTERNOON AND EVENING.
I TWEAKED POPS UP A BIT THAT TIME FRAME BUT THEY MAY END UP HIGHER
YET FOR THAT TIME PERIOD.  BELOW NORMAL HIGH TEMPERATURES EXPECTED
THROUGH AT LEAST THURSDAY THANKS TO THE ENHANCED CONVECTION.

DRIER AIR MOVES INTO NORTHERN AREAS FRIDAY ONWARD WITH DEEP MOISTURE
HANGING NEAR THE INTERNATIONAL BORDER AND SOUTH OF THERE AS WESTERLY
FLOW DEVELOPS OVER THE STATE.  WITH THAT THOUGHT WILL LIKELY HAVE A
DECENT DOWNTURN IN THE CONVECTION OVER THE REGION WITH THE POSSIBLE
EXCEPTION OF ALONG THE BORDER AREA.  THE RELATIVE LACK OF CONVECTION
WILL ALLOW AFTERNOON TEMPERATURES TO RETURN TO NORMAL LEVELS ACROSS
THE REGION SATURDAY ONWARD.  CERNIGLIA

&&

.AVIATION...VALID THRU 21/00Z.
EXPECT SCATTERED TO NUMEROUS SHOWERS PERSISTING INTO TONIGHT...WITH
COVERAGE LESSENING OVERNIGHT. MVFR VISIBILITIES AND WIND GUSTS OF
45-50 KTS WILL OCCUR WITH THE STRONGER TSRA. CLOUD DECKS WILL MAINLY
BE AT 6-12K FT AGL. OUTSIDE OF THUNDERSTORM OUTFLOWS...SURFACE WIND
WILL GENERALLY BE LESS THAN 10 KTS. SCATTERED THUNDERSTORMS AND
SHOWERS POSSIBLE AGAIN STARTING LATE MORNING WEDNESDAY. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&

.FIRE WEATHER...SCATTERED TO NUMEROUS THUNDERSTORMS WILL CONTINUE
INTO TONIGHT AND START AGAIN LATE MORNING WEDNESDAY...AS AMPLE
MOISTURE REMAINS IN PLACE ACROSS SOUTHEASTERN ARIZONA. THE STRONGER
THUNDERSTORMS WILL PRODUCE HEAVY RAINFALL LEADING TO THE POSSIBILITY
OF LOCALIZED FLOODING...AS WELL AS STRONG...GUSTY AND ERRATIC WINDS.
EXPECT SOMEWHAT LESS COVERAGE OF THUNDERSTORMS DURING THE LATTER
PART OF THE WEEK AND NEXT WEEK. HOWEVER...MOISTURE WILL BE
SUFFICIENT FOR ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS. OUTSIDE OF THE THUNDERSTORM OUTFLOWS...20-FOOT WINDS
WILL EXHIBIT NORMAL DIURNAL TRENDS AND WILL BE MOSTLY LESS THAN 15
MPH.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
 FLASH FLOOD WATCH TODAY FROM 12 NOON UNTIL 11 PM FOR MOST OF SE AZ.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON








000
FXUS65 KTWC 191721 AAA
AFDTWC

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE TUCSON AZ
1020 AM MST TUE AUG 19 2014

.UPDATE...UPDATED GRIDS AND ZONES TO HAVE MENTION OF AREAS OF HEAVY
RAIN.

.SYNOPSIS...ABUNDANT MOISTURE COMBINED WITH AN APPROACHING UPPER LOW
WILL GENERATE NUMEROUS SHOWERS AND THUNDERSTORMS TODAY EAST OF THE
TOHONO O`ODHAM NATION WITH THE POTENTIAL FOR VERY HEAVY RAINFALL.  A
SLIGHTLY DRIER ATMOSPHERE AND LESS FORCING WILL ALLOW FOR A MORE
TYPICAL AMOUNT OF CONVECTION THE REMAINDER OF THE WEEK WITH A VERY
MODEST DRYING TREND INTO THIS WEEKEND.  BELOW NORMAL DAYTIME
TEMPERATURES WILL PREVAIL THROUGH THURSDAY FOLLOWED BY A GRADUAL
WARMING TREND LATER THIS WEEK.

&&

.DISCUSSION...AN UPPER LOW CURRENTLY OFF THE CENTRAL COAST OF
CALIFORNIA IS DROPPING SOUTHEAST WITH A LOBE OF ENERGY APPROACHING
YUMA THIS MORNING.  THE MORNING SOUNDING WAS RATHER WET WITH A PW
NEAR 1.7 AND UNSTABLE WITH AN LI OF -5...BASICALLY PRIMED.  THE LOBE
OF ENERGY NEAR YUMA IS FOCUSING THE LIFT ACROSS CENTRAL AND NORTHERN
AZ AT THIS TIME AND THAT IS WHERE ABUNDANT CONVECTION IS ALREADY IN
PLACE.  WE ARE AT THE TAIL END OF THIS ENERGY...ENOUGH THAT
CONVECTION HAS ALREADY DEVELOPED OVER THE CATALINAS AND RINCONS BUT
WILL NEED TO WAIT A FEW MORE HOURS FOR THE LOW TO MOVE CLOSER AND
HEATING TO KICK IN FOR SIGNIFICANT DEVELOPMENT TODAY.  STORM MOTION
TODAY WILL BE TO THE NORTHEAST.

WHILE STRONG WINDS ARE ALWAYS A THREAT WITH THUNDERSTORMS THE
PRIMARY CONCERN TODAY IS HEAVY RAIN AND THE POTENTIAL FOR
RUNOFF/FLOODING PROBLEMS.  SOUTHEAST ARIZONA HAS BEEN PRIMED THE
LAST WEEK WITH AREAS OF HEAVY RAIN SO SOME AREAS WILL RESPOND
QUICKLY TO ADDITIONAL HEAVY RAIN.  CASE IN POINT...HEAVY RAIN LAST
NIGHT OVER THE RINCONS AND SOUTHEAST CATALINAS RESULTED IN HIGH
FLOWS IN THE WASHES WITH 3 ROADS AROUND THE METRO AREA CURRENTLY
CLOSED DUE TO HIGH WATER.  AS A RESULT OF THESE CONCERNS A FLASH
FLOOD WATCH WAS ISSUED ON THE NIGHT SHIFT AND THAT LOOKS GOOD AT
THIS POINT.  AS THE DAY PROGRESSES AND CONVECTION DEVELOPS...REFER
TO THE LATEST STATEMENTS AND WARNINGS TO KEEP UP WITH WHERE FLOODING
IS A THREAT.

AS THE UPPER LOW CONTINUES TO APPROACH THE REGION IT WILL PUSH SOME
DRIER AIR IN OVERNIGHT FROM THE WEST BEHIND THE MAIN AREA OF SHOWERS
AND THUNDERSTORMS WHICH WILL RESULT IN A DECREASE IN THE CONVECTION
ACROSS THE REGION FROM WEST TO EAST.  AS A RESULT OF THE DRIER AIR
MOVING IN ALOFT AND LIMITED FORCING...THERE WILL BE LESS AREAL
COVERAGE OF STORMS ON WEDNESDAY...BUT THANKS TO PLENTY OF NEAR
SURFACE MOISTURE IT SHOULD REMAIN SOMEWHAT ACTIVE.

OPERATIONAL MODELS STILL HAVING ISSUES ON WHEN THE SRN CA UPPER LOW
WILL LIFT THRU THE STATE...ALTHOUGH AT THIS POINT I AM LEANING
TOWARD THE SLOWER SOLUTIONS WHICH WOULD BE THE ECMWF/NAM WHICH
PUSHES THE SYSTEM THROUGH SOMETIME FRIDAY.  THE FASTER GFS IS
SLOWING THE SYSTEM WITH EACH RUN AND THIS MORNINGS 12Z RUN LOOKING
EVEN MORE LIKE THE OTHER TWO.  THIS WOULD MEAN DECENT ACTIVITY AGAIN
THURSDAY INTO EARLY FRI.

ALL THIS CONVECTION AND MOISTURE WILL RESULT IN BELOW NORMAL HIGH
TEMPERATURES TODAY THROUGH THURSDAY...THEN WITH LESS CONVECTION AND
DRIER CONDITIONS TEMPS SHOULD RISE TO MORE NORMAL LEVELS THEREAFTER.
CERNIGLIA

&&

.AVIATION...VALID THRU 20/18Z.
EXPECT SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS DEVELOPING
LATE THIS MORNING OR EARLY AFTERNOON...THEN PERSISTING INTO THE
EVENING HOURS TONIGHT. MVFR VISIBILITIES AND WIND GUSTS OF 45-50 KTS
WILL OCCUR WITH THE STRONGER TSRA. CLOUD DECKS WILL MAINLY BE AT
6-12K FT AGL. OUTSIDE OF THUNDERSTORM OUTFLOWS...SURFACE WIND WILL
GENERALLY BE LESS THAN 10 KTS THRU WEDNESDAY MORNING. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&

.FIRE WEATHER...SCATTERED TO NUMEROUS THUNDERSTORMS WILL OCCUR TODAY
THROUGH WEDNESDAY AS AMPLE MOISTURE REMAINS ACROSS SOUTHEASTERN
ARIZONA.  WITH THE ABUNDANT MOISTURE IN PLACE...LOCALLY HEAVY
RAINFALL IS EXPECTED THIS AFTERNOON AND EVENING WITH THE POTENTIAL
FOR HEAVY RUNOFF/FLOODING PROBLEMS.  ALSO THE STRONGER THUNDERSTORMS
WILL PRODUCE STRONG...GUSTY AND ERRATIC WINDS.  EXPECT SOMEWHAT LESS
COVERAGE OF THUNDERSTORMS DURING THE LATTER PART OF THE WEEK AND
NEXT WEEK.  HOWEVER...MOISTURE WILL BE SUFFICIENT FOR ISOLATED TO
SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS. OUTSIDE OF THE
THUNDERSTORM OUTFLOWS...20-FOOT WINDS WILL EXHIBIT NORMAL DIURNAL
TRENDS AND WILL BE MOSTLY LESS THAN 15 MPH.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
 FLASH FLOOD WATCH TODAY FROM 12 NOON UNTIL 11 PM FOR MOST OF SE AZ.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON











000
FXUS65 KTWC 191721 AAA
AFDTWC

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE TUCSON AZ
1020 AM MST TUE AUG 19 2014

.UPDATE...UPDATED GRIDS AND ZONES TO HAVE MENTION OF AREAS OF HEAVY
RAIN.

.SYNOPSIS...ABUNDANT MOISTURE COMBINED WITH AN APPROACHING UPPER LOW
WILL GENERATE NUMEROUS SHOWERS AND THUNDERSTORMS TODAY EAST OF THE
TOHONO O`ODHAM NATION WITH THE POTENTIAL FOR VERY HEAVY RAINFALL.  A
SLIGHTLY DRIER ATMOSPHERE AND LESS FORCING WILL ALLOW FOR A MORE
TYPICAL AMOUNT OF CONVECTION THE REMAINDER OF THE WEEK WITH A VERY
MODEST DRYING TREND INTO THIS WEEKEND.  BELOW NORMAL DAYTIME
TEMPERATURES WILL PREVAIL THROUGH THURSDAY FOLLOWED BY A GRADUAL
WARMING TREND LATER THIS WEEK.

&&

.DISCUSSION...AN UPPER LOW CURRENTLY OFF THE CENTRAL COAST OF
CALIFORNIA IS DROPPING SOUTHEAST WITH A LOBE OF ENERGY APPROACHING
YUMA THIS MORNING.  THE MORNING SOUNDING WAS RATHER WET WITH A PW
NEAR 1.7 AND UNSTABLE WITH AN LI OF -5...BASICALLY PRIMED.  THE LOBE
OF ENERGY NEAR YUMA IS FOCUSING THE LIFT ACROSS CENTRAL AND NORTHERN
AZ AT THIS TIME AND THAT IS WHERE ABUNDANT CONVECTION IS ALREADY IN
PLACE.  WE ARE AT THE TAIL END OF THIS ENERGY...ENOUGH THAT
CONVECTION HAS ALREADY DEVELOPED OVER THE CATALINAS AND RINCONS BUT
WILL NEED TO WAIT A FEW MORE HOURS FOR THE LOW TO MOVE CLOSER AND
HEATING TO KICK IN FOR SIGNIFICANT DEVELOPMENT TODAY.  STORM MOTION
TODAY WILL BE TO THE NORTHEAST.

WHILE STRONG WINDS ARE ALWAYS A THREAT WITH THUNDERSTORMS THE
PRIMARY CONCERN TODAY IS HEAVY RAIN AND THE POTENTIAL FOR
RUNOFF/FLOODING PROBLEMS.  SOUTHEAST ARIZONA HAS BEEN PRIMED THE
LAST WEEK WITH AREAS OF HEAVY RAIN SO SOME AREAS WILL RESPOND
QUICKLY TO ADDITIONAL HEAVY RAIN.  CASE IN POINT...HEAVY RAIN LAST
NIGHT OVER THE RINCONS AND SOUTHEAST CATALINAS RESULTED IN HIGH
FLOWS IN THE WASHES WITH 3 ROADS AROUND THE METRO AREA CURRENTLY
CLOSED DUE TO HIGH WATER.  AS A RESULT OF THESE CONCERNS A FLASH
FLOOD WATCH WAS ISSUED ON THE NIGHT SHIFT AND THAT LOOKS GOOD AT
THIS POINT.  AS THE DAY PROGRESSES AND CONVECTION DEVELOPS...REFER
TO THE LATEST STATEMENTS AND WARNINGS TO KEEP UP WITH WHERE FLOODING
IS A THREAT.

AS THE UPPER LOW CONTINUES TO APPROACH THE REGION IT WILL PUSH SOME
DRIER AIR IN OVERNIGHT FROM THE WEST BEHIND THE MAIN AREA OF SHOWERS
AND THUNDERSTORMS WHICH WILL RESULT IN A DECREASE IN THE CONVECTION
ACROSS THE REGION FROM WEST TO EAST.  AS A RESULT OF THE DRIER AIR
MOVING IN ALOFT AND LIMITED FORCING...THERE WILL BE LESS AREAL
COVERAGE OF STORMS ON WEDNESDAY...BUT THANKS TO PLENTY OF NEAR
SURFACE MOISTURE IT SHOULD REMAIN SOMEWHAT ACTIVE.

OPERATIONAL MODELS STILL HAVING ISSUES ON WHEN THE SRN CA UPPER LOW
WILL LIFT THRU THE STATE...ALTHOUGH AT THIS POINT I AM LEANING
TOWARD THE SLOWER SOLUTIONS WHICH WOULD BE THE ECMWF/NAM WHICH
PUSHES THE SYSTEM THROUGH SOMETIME FRIDAY.  THE FASTER GFS IS
SLOWING THE SYSTEM WITH EACH RUN AND THIS MORNINGS 12Z RUN LOOKING
EVEN MORE LIKE THE OTHER TWO.  THIS WOULD MEAN DECENT ACTIVITY AGAIN
THURSDAY INTO EARLY FRI.

ALL THIS CONVECTION AND MOISTURE WILL RESULT IN BELOW NORMAL HIGH
TEMPERATURES TODAY THROUGH THURSDAY...THEN WITH LESS CONVECTION AND
DRIER CONDITIONS TEMPS SHOULD RISE TO MORE NORMAL LEVELS THEREAFTER.
CERNIGLIA

&&

.AVIATION...VALID THRU 20/18Z.
EXPECT SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS DEVELOPING
LATE THIS MORNING OR EARLY AFTERNOON...THEN PERSISTING INTO THE
EVENING HOURS TONIGHT. MVFR VISIBILITIES AND WIND GUSTS OF 45-50 KTS
WILL OCCUR WITH THE STRONGER TSRA. CLOUD DECKS WILL MAINLY BE AT
6-12K FT AGL. OUTSIDE OF THUNDERSTORM OUTFLOWS...SURFACE WIND WILL
GENERALLY BE LESS THAN 10 KTS THRU WEDNESDAY MORNING. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&

.FIRE WEATHER...SCATTERED TO NUMEROUS THUNDERSTORMS WILL OCCUR TODAY
THROUGH WEDNESDAY AS AMPLE MOISTURE REMAINS ACROSS SOUTHEASTERN
ARIZONA.  WITH THE ABUNDANT MOISTURE IN PLACE...LOCALLY HEAVY
RAINFALL IS EXPECTED THIS AFTERNOON AND EVENING WITH THE POTENTIAL
FOR HEAVY RUNOFF/FLOODING PROBLEMS.  ALSO THE STRONGER THUNDERSTORMS
WILL PRODUCE STRONG...GUSTY AND ERRATIC WINDS.  EXPECT SOMEWHAT LESS
COVERAGE OF THUNDERSTORMS DURING THE LATTER PART OF THE WEEK AND
NEXT WEEK.  HOWEVER...MOISTURE WILL BE SUFFICIENT FOR ISOLATED TO
SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS. OUTSIDE OF THE
THUNDERSTORM OUTFLOWS...20-FOOT WINDS WILL EXHIBIT NORMAL DIURNAL
TRENDS AND WILL BE MOSTLY LESS THAN 15 MPH.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
 FLASH FLOOD WATCH TODAY FROM 12 NOON UNTIL 11 PM FOR MOST OF SE AZ.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON












000
FXUS65 KTWC 191602
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
900 AM MST TUE AUG 19 2014

.SYNOPSIS...ABUNDANT MOISTURE COMBINED WITH AN APPROACHING UPPER LOW
WILL GENERATE NUMEROUS SHOWERS AND THUNDERSTORMS TODAY EAST OF THE
TOHONO O`ODHAM NATION WITH THE POTENTIAL FOR VERY HEAVY RAINFALL.  A
SLIGHTLY DRIER ATMOSPHERE AND LESS FORCING WILL ALLOW FOR A MORE
TYPICAL AMOUNT OF CONVECTION THE REMAINDER OF THE WEEK WITH A VERY
MODEST DRYING TREND INTO THIS WEEKEND.  BELOW NORMAL DAYTIME
TEMPERATURES WILL PREVAIL THROUGH THURSDAY FOLLOWED BY A GRADUAL
WARMING TREND LATER THIS WEEK.

&&

.DISCUSSION...AN UPPER LOW CURRENTLY OFF THE CENTRAL COAST OF
CALIFORNIA IS DROPPING SOUTHEAST WITH A LOBE OF ENERGY APPROACHING
YUMA THIS MORNING.  THE MORNING SOUNDING WAS RATHER WET WITH A PW
NEAR 1.7 AND UNSTABLE WITH AN LI OF -5...BASICALLY PRIMED.  THE LOBE
OF ENERGY NEAR YUMA IS FOCUSING THE LIFT ACROSS CENTRAL AND NORTHERN
AZ AT THIS TIME AND THAT IS WHERE ABUNDANT CONVECTION IS ALREADY IN
PLACE.  WE ARE AT THE TAIL END OF THIS ENERGY...ENOUGH THAT
CONVECTION HAS ALREADY DEVELOPED OVER THE CATALINAS AND RINCONS BUT
WILL NEED TO WAIT A FEW MORE HOURS FOR THE LOW TO MOVE CLOSER AND
HEATING TO KICK IN FOR SIGNIFICANT DEVELOPMENT TODAY.  STORM MOTION
TODAY WILL BE TO THE NORTHEAST.

WHILE STRONG WINDS ARE ALWAYS A THREAT WITH THUNDERSTORMS THE
PRIMARY CONCERN TODAY IS HEAVY RAIN AND THE POTENTIAL FOR
RUNOFF/FLOODING PROBLEMS.  SOUTHEAST ARIZONA HAS BEEN PRIMED THE
LAST WEEK WITH AREAS OF HEAVY RAIN SO SOME AREAS WILL RESPOND
QUICKLY TO ADDITIONAL HEAVY RAIN.  CASE IN POINT...HEAVY RAIN LAST
NIGHT OVER THE RINCONS AND SOUTHEAST CATALINAS RESULTED IN HIGH
FLOWS IN THE WASHES WITH 3 ROADS AROUND THE METRO AREA CURRENTLY
CLOSED DUE TO HIGH WATER.  AS A RESULT OF THESE CONCERNS A FLASH
FLOOD WATCH WAS ISSUED ON THE NIGHT SHIFT AND THAT LOOKS GOOD AT
THIS POINT.  AS THE DAY PROGRESSES AND CONVECTION DEVELOPS...REFER
TO THE LATEST STATEMENTS AND WARNINGS TO KEEP UP WITH WHERE FLOODING
IS A THREAT.

AS THE UPPER LOW CONTINUES TO APPROACH THE REGION IT WILL PUSH SOME
DRIER AIR IN OVERNIGHT FROM THE WEST BEHIND THE MAIN AREA OF SHOWERS
AND THUNDERSTORMS WHICH WILL RESULT IN A DECREASE IN THE CONVECTION
ACROSS THE REGION FROM WEST TO EAST.  AS A RESULT OF THE DRIER AIR
MOVING IN ALOFT AND LIMITED FORCING...THERE WILL BE LESS AREAL
COVERAGE OF STORMS ON WEDNESDAY...BUT THANKS TO PLENTY OF NEAR
SURFACE MOISTURE IT SHOULD REMAIN SOMEWHAT ACTIVE.

OPERATIONAL MODELS STILL HAVING ISSUES ON WHEN THE SRN CA UPPER LOW
WILL LIFT THRU THE STATE...ALTHOUGH AT THIS POINT I AM LEANING
TOWARD THE SLOWER SOLUTIONS WHICH WOULD BE THE ECMWF/NAM WHICH
PUSHES THE SYSTEM THROUGH SOMETIME FRIDAY.  THE FASTER GFS IS
SLOWING THE SYSTEM WITH EACH RUN AND THIS MORNINGS 12Z RUN LOOKING
EVEN MORE LIKE THE OTHER TWO.  THIS WOULD MEAN DECENT ACTIVITY AGAIN
THURSDAY INTO EARLY FRI.

ALL THIS CONVECTION AND MOISTURE WILL RESULT IN BELOW NORMAL HIGH
TEMPERATURES TODAY THROUGH THURSDAY...THEN WITH LESS CONVECTION AND
DRIER CONDITIONS TEMPS SHOULD RISE TO MORE NORMAL LEVELS THEREAFTER.
CERNIGLIA

&&

.AVIATION...VALID THRU 20/18Z.
EXPECT SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS DEVELOPING
LATE THIS MORNING OR EARLY AFTERNOON...THEN PERSISTING INTO THE
EVENING HOURS TONIGHT. MVFR VISIBILITIES AND WIND GUSTS OF 45-50 KTS
WILL OCCUR WITH THE STRONGER TSRA. CLOUD DECKS WILL MAINLY BE AT
6-12K FT AGL. OUTSIDE OF THUNDERSTORM OUTFLOWS...SURFACE WIND WILL
GENERALLY BE LESS THAN 10 KTS THRU WEDNESDAY MORNING. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&

.FIRE WEATHER...SCATTERED TO NUMEROUS THUNDERSTORMS WILL OCCUR TODAY
THROUGH WEDNESDAY AS AMPLE MOISTURE REMAINS ACROSS SOUTHEASTERN
ARIZONA.  WITH THE ABUNDANT MOISTURE IN PLACE...LOCALLY HEAVY
RAINFALL IS EXPECTED THIS AFTERNOON AND EVENING WITH THE POTENTIAL
FOR HEAVY RUNOFF/FLOODING PROBLEMS.  ALSO THE STRONGER THUNDERSTORMS
WILL PRODUCE STRONG...GUSTY AND ERRATIC WINDS.  EXPECT SOMEWHAT LESS
COVERAGE OF THUNDERSTORMS DURING THE LATTER PART OF THE WEEK AND
NEXT WEEK.  HOWEVER...MOISTURE WILL BE SUFFICIENT FOR ISOLATED TO
SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS. OUTSIDE OF THE
THUNDERSTORM OUTFLOWS...20-FOOT WINDS WILL EXHIBIT NORMAL DIURNAL
TRENDS AND WILL BE MOSTLY LESS THAN 15 MPH.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
 FLASH FLOOD WATCH TODAY FROM 12 NOON UNTIL 11 PM FOR MOST OF SE AZ.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON








000
FXUS65 KTWC 191602
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
900 AM MST TUE AUG 19 2014

.SYNOPSIS...ABUNDANT MOISTURE COMBINED WITH AN APPROACHING UPPER LOW
WILL GENERATE NUMEROUS SHOWERS AND THUNDERSTORMS TODAY EAST OF THE
TOHONO O`ODHAM NATION WITH THE POTENTIAL FOR VERY HEAVY RAINFALL.  A
SLIGHTLY DRIER ATMOSPHERE AND LESS FORCING WILL ALLOW FOR A MORE
TYPICAL AMOUNT OF CONVECTION THE REMAINDER OF THE WEEK WITH A VERY
MODEST DRYING TREND INTO THIS WEEKEND.  BELOW NORMAL DAYTIME
TEMPERATURES WILL PREVAIL THROUGH THURSDAY FOLLOWED BY A GRADUAL
WARMING TREND LATER THIS WEEK.

&&

.DISCUSSION...AN UPPER LOW CURRENTLY OFF THE CENTRAL COAST OF
CALIFORNIA IS DROPPING SOUTHEAST WITH A LOBE OF ENERGY APPROACHING
YUMA THIS MORNING.  THE MORNING SOUNDING WAS RATHER WET WITH A PW
NEAR 1.7 AND UNSTABLE WITH AN LI OF -5...BASICALLY PRIMED.  THE LOBE
OF ENERGY NEAR YUMA IS FOCUSING THE LIFT ACROSS CENTRAL AND NORTHERN
AZ AT THIS TIME AND THAT IS WHERE ABUNDANT CONVECTION IS ALREADY IN
PLACE.  WE ARE AT THE TAIL END OF THIS ENERGY...ENOUGH THAT
CONVECTION HAS ALREADY DEVELOPED OVER THE CATALINAS AND RINCONS BUT
WILL NEED TO WAIT A FEW MORE HOURS FOR THE LOW TO MOVE CLOSER AND
HEATING TO KICK IN FOR SIGNIFICANT DEVELOPMENT TODAY.  STORM MOTION
TODAY WILL BE TO THE NORTHEAST.

WHILE STRONG WINDS ARE ALWAYS A THREAT WITH THUNDERSTORMS THE
PRIMARY CONCERN TODAY IS HEAVY RAIN AND THE POTENTIAL FOR
RUNOFF/FLOODING PROBLEMS.  SOUTHEAST ARIZONA HAS BEEN PRIMED THE
LAST WEEK WITH AREAS OF HEAVY RAIN SO SOME AREAS WILL RESPOND
QUICKLY TO ADDITIONAL HEAVY RAIN.  CASE IN POINT...HEAVY RAIN LAST
NIGHT OVER THE RINCONS AND SOUTHEAST CATALINAS RESULTED IN HIGH
FLOWS IN THE WASHES WITH 3 ROADS AROUND THE METRO AREA CURRENTLY
CLOSED DUE TO HIGH WATER.  AS A RESULT OF THESE CONCERNS A FLASH
FLOOD WATCH WAS ISSUED ON THE NIGHT SHIFT AND THAT LOOKS GOOD AT
THIS POINT.  AS THE DAY PROGRESSES AND CONVECTION DEVELOPS...REFER
TO THE LATEST STATEMENTS AND WARNINGS TO KEEP UP WITH WHERE FLOODING
IS A THREAT.

AS THE UPPER LOW CONTINUES TO APPROACH THE REGION IT WILL PUSH SOME
DRIER AIR IN OVERNIGHT FROM THE WEST BEHIND THE MAIN AREA OF SHOWERS
AND THUNDERSTORMS WHICH WILL RESULT IN A DECREASE IN THE CONVECTION
ACROSS THE REGION FROM WEST TO EAST.  AS A RESULT OF THE DRIER AIR
MOVING IN ALOFT AND LIMITED FORCING...THERE WILL BE LESS AREAL
COVERAGE OF STORMS ON WEDNESDAY...BUT THANKS TO PLENTY OF NEAR
SURFACE MOISTURE IT SHOULD REMAIN SOMEWHAT ACTIVE.

OPERATIONAL MODELS STILL HAVING ISSUES ON WHEN THE SRN CA UPPER LOW
WILL LIFT THRU THE STATE...ALTHOUGH AT THIS POINT I AM LEANING
TOWARD THE SLOWER SOLUTIONS WHICH WOULD BE THE ECMWF/NAM WHICH
PUSHES THE SYSTEM THROUGH SOMETIME FRIDAY.  THE FASTER GFS IS
SLOWING THE SYSTEM WITH EACH RUN AND THIS MORNINGS 12Z RUN LOOKING
EVEN MORE LIKE THE OTHER TWO.  THIS WOULD MEAN DECENT ACTIVITY AGAIN
THURSDAY INTO EARLY FRI.

ALL THIS CONVECTION AND MOISTURE WILL RESULT IN BELOW NORMAL HIGH
TEMPERATURES TODAY THROUGH THURSDAY...THEN WITH LESS CONVECTION AND
DRIER CONDITIONS TEMPS SHOULD RISE TO MORE NORMAL LEVELS THEREAFTER.
CERNIGLIA

&&

.AVIATION...VALID THRU 20/18Z.
EXPECT SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS DEVELOPING
LATE THIS MORNING OR EARLY AFTERNOON...THEN PERSISTING INTO THE
EVENING HOURS TONIGHT. MVFR VISIBILITIES AND WIND GUSTS OF 45-50 KTS
WILL OCCUR WITH THE STRONGER TSRA. CLOUD DECKS WILL MAINLY BE AT
6-12K FT AGL. OUTSIDE OF THUNDERSTORM OUTFLOWS...SURFACE WIND WILL
GENERALLY BE LESS THAN 10 KTS THRU WEDNESDAY MORNING. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&

.FIRE WEATHER...SCATTERED TO NUMEROUS THUNDERSTORMS WILL OCCUR TODAY
THROUGH WEDNESDAY AS AMPLE MOISTURE REMAINS ACROSS SOUTHEASTERN
ARIZONA.  WITH THE ABUNDANT MOISTURE IN PLACE...LOCALLY HEAVY
RAINFALL IS EXPECTED THIS AFTERNOON AND EVENING WITH THE POTENTIAL
FOR HEAVY RUNOFF/FLOODING PROBLEMS.  ALSO THE STRONGER THUNDERSTORMS
WILL PRODUCE STRONG...GUSTY AND ERRATIC WINDS.  EXPECT SOMEWHAT LESS
COVERAGE OF THUNDERSTORMS DURING THE LATTER PART OF THE WEEK AND
NEXT WEEK.  HOWEVER...MOISTURE WILL BE SUFFICIENT FOR ISOLATED TO
SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS. OUTSIDE OF THE
THUNDERSTORM OUTFLOWS...20-FOOT WINDS WILL EXHIBIT NORMAL DIURNAL
TRENDS AND WILL BE MOSTLY LESS THAN 15 MPH.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
 FLASH FLOOD WATCH TODAY FROM 12 NOON UNTIL 11 PM FOR MOST OF SE AZ.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON









000
FXUS65 KTWC 191012
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
310 AM MST TUE AUG 19 2014

.SYNOPSIS...AMPLE MOISTURE WILL PROVIDE SCATTERED TO NUMEROUS
THUNDERSTORMS THROUGH MIDWEEK. SOME STORMS WILL PRODUCE GUSTY WINDS
AND HEAVY RAINFALL. A VERY MODEST DRYING TREND WILL THEN OCCUR
DURING THE LATTER PART OF THE WEEK AND INTO THIS WEEKEND. HOWEVER...
ENOUGH MOISTURE WILL EXIST FOR ISOLATED TO SCATTERED THUNDERSTORMS.
BELOW NORMAL DAYTIME TEMPERATURES WILL PREVAIL THROUGH WEDNESDAY
FOLLOWED BY A GRADUAL WARMING TREND LATER THIS WEEK.

&&

.DISCUSSION...ISOLATED SHOWERS AND THUNDERSTORMS WERE OCCURRING
ACROSS ERN SECTIONS OF THE FORECAST AREA AS OF 3 AM. OUT WEST...A
FEW STORMS WERE TRYING TO DEVELOP AS DYNAMICS START TO INCREASE IN
ADVANCE OF APPROACHING UPPER LEVEL LOW....WHICH WAS CENTERED JUST
WEST OF FRISCO AND MOVING S. BY THIS EVENING...THIS LOW WILL BE
CENTERED NEAR THE LA BASIN. INCREASING UPPER DIFFLUENCE AHEAD OF
THIS FEATURE WILL COMBINE WITH A VERY MOIST ATMOSPHERE TO GENERATE
WIDESPREAD SHOWERS AND SCATTERED THUNDERSTORMS ACROSS SE ARIZONA.
HEAVY RAIN IS LIKELY WITH SOME OF THE STRONGER STORMS AND WITH SOME
AREAS RECORDING PRETTY GOOD RAINFALL AMOUNTS OVER THE PAST FOUR
DAYS...FEEL THAT THE THREAT IS UP FOR FLASH FLOODING. WITH THAT
SAID I HAVE DECIDED TO HOIST A FLASH FLOOD WATCH FOR MOST OF SE
ARIZONA FROM 12 NOON UNTIL 11 PM.

SOME DRIER AIR WILL PUSH IN OVERNIGHT FROM THE WEST BEHIND THE MAIN
AREA OF SHOWERS AND THUNDERSTORMS. WITH THE UPPER LOW NEAR SAN DIEGO
AND SLIGHTLY DRIER AIR OVER THE AREA...WILL SEE LESS AREAL COVERAGE
OF STORMS ON WEDNESDAY...BUT STILL RATHER ACTIVE.

OPERATIONAL MODELS STILL HAVING ISSUES ON WHEN OR IF THE SRN CA
UPPER LOW WILL LIFT THRU THE STATE...GFS ON THU/ECMWF ON FRI...OR
SIT OFFSHORE INTO THE WEEKEND ALA THE CANADIAN. FOR NOW DIDN`T MAKE
MUCH CHANGE TO THE INHERITED FORECAST STARTING THU INTO THE WEEKEND
WHICH MAINTAINS ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS.

BELOW NORMAL HIGHS TODAY THROUGH THURSDAY THAN WARMER INTO THE
WEEKEND.

&&

.AVIATION...VALID THRU 20/12Z.
EXPECT SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS DEVELOPING
THIS AFTERNOON...PERSISTING INTO THE EVENING HOURS TONIGHT. MVFR
VISIBILITIES AND WIND GUSTS OF 45-50 KTS WILL OCCUR WITH THE
STRONGER TSRA. CLOUD DECKS WILL MAINLY BE AT 6-12K FT AGL. OUTSIDE
OF THUNDERSTORM OUTFLOWS...SURFACE WIND WILL GENERALLY BE LESS THAN
10 KTS THRU WEDNESDAY MORNING. AVIATION DISCUSSION NOT UPDATED FOR
TAF AMENDMENTS.

&&

.FIRE WEATHER...SCATTERED TO NUMEROUS THUNDERSTORMS WILL OCCUR
THROUGH WEDNESDAY AS AMPLE MOISTURE REMAINS ACROSS SOUTHEASTERN
ARIZONA. THE STRONGER THUNDERSTORMS WILL PRODUCE STRONG...GUSTY AND
ERRATIC WINDS. EXPECT SOMEWHAT LESS COVERAGE OF THUNDERSTORMS DURING
THE LATTER PART OF THE WEEK AND NEXT WEEK. HOWEVER...MOISTURE WILL
BE SUFFICIENT FOR ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS. OUTSIDE OF THE THUNDERSTORM OUTFLOWS...20-FOOT WINDS
WILL EXHIBIT NORMAL DIURNAL TRENDS AND WILL BE MOSTLY LESS THAN 15
MPH.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
 FLASH FLOOD WATCH TODAY FROM 12 NOON UNTIL 11 PM FOR MOST OF SE AZ.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON







000
FXUS65 KTWC 191012
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
310 AM MST TUE AUG 19 2014

.SYNOPSIS...AMPLE MOISTURE WILL PROVIDE SCATTERED TO NUMEROUS
THUNDERSTORMS THROUGH MIDWEEK. SOME STORMS WILL PRODUCE GUSTY WINDS
AND HEAVY RAINFALL. A VERY MODEST DRYING TREND WILL THEN OCCUR
DURING THE LATTER PART OF THE WEEK AND INTO THIS WEEKEND. HOWEVER...
ENOUGH MOISTURE WILL EXIST FOR ISOLATED TO SCATTERED THUNDERSTORMS.
BELOW NORMAL DAYTIME TEMPERATURES WILL PREVAIL THROUGH WEDNESDAY
FOLLOWED BY A GRADUAL WARMING TREND LATER THIS WEEK.

&&

.DISCUSSION...ISOLATED SHOWERS AND THUNDERSTORMS WERE OCCURRING
ACROSS ERN SECTIONS OF THE FORECAST AREA AS OF 3 AM. OUT WEST...A
FEW STORMS WERE TRYING TO DEVELOP AS DYNAMICS START TO INCREASE IN
ADVANCE OF APPROACHING UPPER LEVEL LOW....WHICH WAS CENTERED JUST
WEST OF FRISCO AND MOVING S. BY THIS EVENING...THIS LOW WILL BE
CENTERED NEAR THE LA BASIN. INCREASING UPPER DIFFLUENCE AHEAD OF
THIS FEATURE WILL COMBINE WITH A VERY MOIST ATMOSPHERE TO GENERATE
WIDESPREAD SHOWERS AND SCATTERED THUNDERSTORMS ACROSS SE ARIZONA.
HEAVY RAIN IS LIKELY WITH SOME OF THE STRONGER STORMS AND WITH SOME
AREAS RECORDING PRETTY GOOD RAINFALL AMOUNTS OVER THE PAST FOUR
DAYS...FEEL THAT THE THREAT IS UP FOR FLASH FLOODING. WITH THAT
SAID I HAVE DECIDED TO HOIST A FLASH FLOOD WATCH FOR MOST OF SE
ARIZONA FROM 12 NOON UNTIL 11 PM.

SOME DRIER AIR WILL PUSH IN OVERNIGHT FROM THE WEST BEHIND THE MAIN
AREA OF SHOWERS AND THUNDERSTORMS. WITH THE UPPER LOW NEAR SAN DIEGO
AND SLIGHTLY DRIER AIR OVER THE AREA...WILL SEE LESS AREAL COVERAGE
OF STORMS ON WEDNESDAY...BUT STILL RATHER ACTIVE.

OPERATIONAL MODELS STILL HAVING ISSUES ON WHEN OR IF THE SRN CA
UPPER LOW WILL LIFT THRU THE STATE...GFS ON THU/ECMWF ON FRI...OR
SIT OFFSHORE INTO THE WEEKEND ALA THE CANADIAN. FOR NOW DIDN`T MAKE
MUCH CHANGE TO THE INHERITED FORECAST STARTING THU INTO THE WEEKEND
WHICH MAINTAINS ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS.

BELOW NORMAL HIGHS TODAY THROUGH THURSDAY THAN WARMER INTO THE
WEEKEND.

&&

.AVIATION...VALID THRU 20/12Z.
EXPECT SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS DEVELOPING
THIS AFTERNOON...PERSISTING INTO THE EVENING HOURS TONIGHT. MVFR
VISIBILITIES AND WIND GUSTS OF 45-50 KTS WILL OCCUR WITH THE
STRONGER TSRA. CLOUD DECKS WILL MAINLY BE AT 6-12K FT AGL. OUTSIDE
OF THUNDERSTORM OUTFLOWS...SURFACE WIND WILL GENERALLY BE LESS THAN
10 KTS THRU WEDNESDAY MORNING. AVIATION DISCUSSION NOT UPDATED FOR
TAF AMENDMENTS.

&&

.FIRE WEATHER...SCATTERED TO NUMEROUS THUNDERSTORMS WILL OCCUR
THROUGH WEDNESDAY AS AMPLE MOISTURE REMAINS ACROSS SOUTHEASTERN
ARIZONA. THE STRONGER THUNDERSTORMS WILL PRODUCE STRONG...GUSTY AND
ERRATIC WINDS. EXPECT SOMEWHAT LESS COVERAGE OF THUNDERSTORMS DURING
THE LATTER PART OF THE WEEK AND NEXT WEEK. HOWEVER...MOISTURE WILL
BE SUFFICIENT FOR ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS. OUTSIDE OF THE THUNDERSTORM OUTFLOWS...20-FOOT WINDS
WILL EXHIBIT NORMAL DIURNAL TRENDS AND WILL BE MOSTLY LESS THAN 15
MPH.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
 FLASH FLOOD WATCH TODAY FROM 12 NOON UNTIL 11 PM FOR MOST OF SE AZ.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON








000
FXUS65 KTWC 190417
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
915 PM MST MON AUG 18 2014

.SYNOPSIS...AMPLE MOISTURE WILL PROVIDE SCATTERED TO NUMEROUS
THUNDERSTORMS THROUGH MIDWEEK. SOME STORMS WILL PRODUCE GUSTY WINDS
AND HEAVY RAINFALL. A VERY MODEST DRYING TREND WILL THEN OCCUR
DURING THE LATTER PART OF THE WEEK AND INTO THIS WEEKEND. HOWEVER...
ENOUGH MOISTURE WILL EXIST FOR ISOLATED TO SCATTERED THUNDERSTORMS.
BELOW NORMAL DAYTIME TEMPERATURES WILL PREVAIL THROUGH WEDNESDAY
FOLLOWED BY A GRADUAL WARMING TREND LATER THIS WEEK.

&&

.DISCUSSION...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS
CONTINUED LATE THIS EVENING. NEW DEVELOPMENT HAS BEEN FOCUSED OVER
THE FOOTHILLS OF THE CATALINA AND RINCON MOUNTAINS WERE VERY HEAVY
RAINFALL WILL BE A CONCERN THROUGH MIDNIGHT TONIGHT. RECENT RADAR
IMAGERY WAS ALSO SHOWING SOME DEVELOPMENT ACROSS EASTERN SECTIONS OF
THE TUCSON AREA GENERALLY ALONG HOUGHTON ROAD. NEEDLESS TO SAY...THE
THUNDERSTORM ACTIVITY WAS NOT OVER WITH FOR THE NIGHT. IN FACT...IT
APPEARED THAT IT WAS JUST GETTING STARTED FOR MUCH OF EASTERN PIMA
COUNTY. AT ANY RATE...CURRENT FORECAST KEEPS POP VALUES UP FOR
OVERNIGHT SO NO ADJUSTMENTS NECESSARY. PLEASE REFER TO THE
ADDITIONAL SECTIONS FOR MORE DETAILS.

&&

.AVIATION...VALID THRU 20/06Z.
EXPECT SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS THROUGH
TUESDAY AFTERNOON. MVFR VISIBILITIES AND BRIEF WIND GUSTS OF 45-50
KTS WILL OCCUR WITH THE STRONGER TSRA. OTHERWISE...CLOUD DECKS WILL
MAINLY BE AT 6-12K FT AGL AND SURFACE WIND WILL GENERALLY BE LESS
THAN 10 KTS THRU TUESDAY AFTERNOON. AVIATION DISCUSSION NOT UPDATED
FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...SCATTERED TO NUMEROUS THUNDERSTORMS WILL OCCUR
THROUGH WEDNESDAY AS AMPLE MOISTURE REMAINS ACROSS SOUTHEAST
ARIZONA. THE STRONGER THUNDERSTORMS WILL PRODUCE STRONG...GUSTY AND
ERRATIC WINDS. EXPECT SOMEWHAT LESS COVERAGE OF THUNDERSTORMS DURING
THE LATTER PART OF THE WEEK AND NEXT WEEK. HOWEVER...MOISTURE WILL
BE SUFFICIENT TO PROVIDE ISOLATED TO SCATTERED MAINLY AFTERNOON AND
EVENING THUNDERSTORMS. OTHERWISE...20-FOOT WINDS WILL EXHIBIT NORMAL
DIURNAL TRENDS AND BE MOSTLY LESS THAN 15 MPH.

&&

.PREV DISCUSSION...HIGH PRESSURE ALOFT CENTERED OVER NWRN NEW MEXICO
THIS AFTERNOON WILL BECOME POSITIONED OVER THE LOWER MISSISSIPPI
RIVER VALLEY REGION BY WED AS A CLOSED UPPER LOW DEVELOPS OVER SRN
CALIFORNIA. A STRONGLY DIFFLUENT FLOW ALOFT REGIME IN COMBINATION
WITH AMPLE MOISTURE SHOULD ENHANCE COVERAGE OF SHOWERS/TSTMS LATER
TONIGHT INTO TUE. POPS WERE INCREASED TO DEPICT SCATTERED TO
NUMEROUS COVERAGE OF SHOWERS/TSTMS BY TUE AFTERNOON.

THERE IS STILL SOME UNCERTAINTY REGARDING THE EXACT PERIOD FOR THE
HEAVIEST RAINFALL TO OCCUR. ALTHOUGH STORM MOTIONS MAY BE RELATIVELY
FAST...THE PROGGED PATTERN SUGGESTS THAT TRAINING STORMS THAT WOULD
ENHANCE HEAVY RAINFALL MAY OCCUR. AT ANY RATE...HAVE DEFERRED A
POTENTIAL FLASH FLOOD WATCH ISSUANCE TO SUBSEQUENT SHIFTS. SOMEWHAT
LESS COVERAGE OF SHOWERS/TSTMS SHOULD OCCUR WED VERSUS TUE.
HOWEVER...CONTINUED AMPLE MOISTURE IN COMBINATION WITH A SOMEWHAT
DIFFLUENT FLOW ALOFT REGIME AHEAD OF THE SRN CALIFORNIA UPPER LOW
WILL PROVIDE SCATTERED SHOWERS/TSTMS ACROSS MUCH OF SE AZ.

18/12Z GFS/ECMWF WERE SIMILAR WITH SHUNTING THE DEEPER MOISTURE EWD
INTO WRN NEW MEXICO THUR AS THE SRN CALIFORNIA UPPER LOW BEGINS TO
MERGE WITH THE NRN STREAM TROUGH. A VERY GRADUAL DRYING TREND IS
PROGGED TO OCCUR FRI-SAT UNDER LIGHT GENERALLY WLY FLOW ALOFT.
GFS/ECMWF WERE SIMILAR WITH DEPICTING INCREASED MOISTURE SUN AS THE
MID-LEVEL FLOW BECOMES ELY AND A WEAK UPPER LOW APPROACHES FROM THE
SOUTH. THE UPSHOT FOR THUR-SUN...ENOUGH MOISTURE WILL EXIST FOR
ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING SHOWERS/TSTMS.

HIGH TEMPS TUE-WED ARE FORECAST TO AVERAGE ABOUT 5-8 DEGS F OR SO
BELOW NORMAL. A WARMING TREND IS ON TAP DURING THE LATTER PART OF
THE WEEK...WITH DAYTIME TEMPS RETURNING CLOSE TO NORMAL THIS
UPCOMING WEEKEND.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON










000
FXUS65 KTWC 190417
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
915 PM MST MON AUG 18 2014

.SYNOPSIS...AMPLE MOISTURE WILL PROVIDE SCATTERED TO NUMEROUS
THUNDERSTORMS THROUGH MIDWEEK. SOME STORMS WILL PRODUCE GUSTY WINDS
AND HEAVY RAINFALL. A VERY MODEST DRYING TREND WILL THEN OCCUR
DURING THE LATTER PART OF THE WEEK AND INTO THIS WEEKEND. HOWEVER...
ENOUGH MOISTURE WILL EXIST FOR ISOLATED TO SCATTERED THUNDERSTORMS.
BELOW NORMAL DAYTIME TEMPERATURES WILL PREVAIL THROUGH WEDNESDAY
FOLLOWED BY A GRADUAL WARMING TREND LATER THIS WEEK.

&&

.DISCUSSION...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS
CONTINUED LATE THIS EVENING. NEW DEVELOPMENT HAS BEEN FOCUSED OVER
THE FOOTHILLS OF THE CATALINA AND RINCON MOUNTAINS WERE VERY HEAVY
RAINFALL WILL BE A CONCERN THROUGH MIDNIGHT TONIGHT. RECENT RADAR
IMAGERY WAS ALSO SHOWING SOME DEVELOPMENT ACROSS EASTERN SECTIONS OF
THE TUCSON AREA GENERALLY ALONG HOUGHTON ROAD. NEEDLESS TO SAY...THE
THUNDERSTORM ACTIVITY WAS NOT OVER WITH FOR THE NIGHT. IN FACT...IT
APPEARED THAT IT WAS JUST GETTING STARTED FOR MUCH OF EASTERN PIMA
COUNTY. AT ANY RATE...CURRENT FORECAST KEEPS POP VALUES UP FOR
OVERNIGHT SO NO ADJUSTMENTS NECESSARY. PLEASE REFER TO THE
ADDITIONAL SECTIONS FOR MORE DETAILS.

&&

.AVIATION...VALID THRU 20/06Z.
EXPECT SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS THROUGH
TUESDAY AFTERNOON. MVFR VISIBILITIES AND BRIEF WIND GUSTS OF 45-50
KTS WILL OCCUR WITH THE STRONGER TSRA. OTHERWISE...CLOUD DECKS WILL
MAINLY BE AT 6-12K FT AGL AND SURFACE WIND WILL GENERALLY BE LESS
THAN 10 KTS THRU TUESDAY AFTERNOON. AVIATION DISCUSSION NOT UPDATED
FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...SCATTERED TO NUMEROUS THUNDERSTORMS WILL OCCUR
THROUGH WEDNESDAY AS AMPLE MOISTURE REMAINS ACROSS SOUTHEAST
ARIZONA. THE STRONGER THUNDERSTORMS WILL PRODUCE STRONG...GUSTY AND
ERRATIC WINDS. EXPECT SOMEWHAT LESS COVERAGE OF THUNDERSTORMS DURING
THE LATTER PART OF THE WEEK AND NEXT WEEK. HOWEVER...MOISTURE WILL
BE SUFFICIENT TO PROVIDE ISOLATED TO SCATTERED MAINLY AFTERNOON AND
EVENING THUNDERSTORMS. OTHERWISE...20-FOOT WINDS WILL EXHIBIT NORMAL
DIURNAL TRENDS AND BE MOSTLY LESS THAN 15 MPH.

&&

.PREV DISCUSSION...HIGH PRESSURE ALOFT CENTERED OVER NWRN NEW MEXICO
THIS AFTERNOON WILL BECOME POSITIONED OVER THE LOWER MISSISSIPPI
RIVER VALLEY REGION BY WED AS A CLOSED UPPER LOW DEVELOPS OVER SRN
CALIFORNIA. A STRONGLY DIFFLUENT FLOW ALOFT REGIME IN COMBINATION
WITH AMPLE MOISTURE SHOULD ENHANCE COVERAGE OF SHOWERS/TSTMS LATER
TONIGHT INTO TUE. POPS WERE INCREASED TO DEPICT SCATTERED TO
NUMEROUS COVERAGE OF SHOWERS/TSTMS BY TUE AFTERNOON.

THERE IS STILL SOME UNCERTAINTY REGARDING THE EXACT PERIOD FOR THE
HEAVIEST RAINFALL TO OCCUR. ALTHOUGH STORM MOTIONS MAY BE RELATIVELY
FAST...THE PROGGED PATTERN SUGGESTS THAT TRAINING STORMS THAT WOULD
ENHANCE HEAVY RAINFALL MAY OCCUR. AT ANY RATE...HAVE DEFERRED A
POTENTIAL FLASH FLOOD WATCH ISSUANCE TO SUBSEQUENT SHIFTS. SOMEWHAT
LESS COVERAGE OF SHOWERS/TSTMS SHOULD OCCUR WED VERSUS TUE.
HOWEVER...CONTINUED AMPLE MOISTURE IN COMBINATION WITH A SOMEWHAT
DIFFLUENT FLOW ALOFT REGIME AHEAD OF THE SRN CALIFORNIA UPPER LOW
WILL PROVIDE SCATTERED SHOWERS/TSTMS ACROSS MUCH OF SE AZ.

18/12Z GFS/ECMWF WERE SIMILAR WITH SHUNTING THE DEEPER MOISTURE EWD
INTO WRN NEW MEXICO THUR AS THE SRN CALIFORNIA UPPER LOW BEGINS TO
MERGE WITH THE NRN STREAM TROUGH. A VERY GRADUAL DRYING TREND IS
PROGGED TO OCCUR FRI-SAT UNDER LIGHT GENERALLY WLY FLOW ALOFT.
GFS/ECMWF WERE SIMILAR WITH DEPICTING INCREASED MOISTURE SUN AS THE
MID-LEVEL FLOW BECOMES ELY AND A WEAK UPPER LOW APPROACHES FROM THE
SOUTH. THE UPSHOT FOR THUR-SUN...ENOUGH MOISTURE WILL EXIST FOR
ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING SHOWERS/TSTMS.

HIGH TEMPS TUE-WED ARE FORECAST TO AVERAGE ABOUT 5-8 DEGS F OR SO
BELOW NORMAL. A WARMING TREND IS ON TAP DURING THE LATTER PART OF
THE WEEK...WITH DAYTIME TEMPS RETURNING CLOSE TO NORMAL THIS
UPCOMING WEEKEND.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON









000
FXUS65 KTWC 182122
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
220 PM MST MON AUG 18 2014

.SYNOPSIS...AMPLE MOISTURE WILL PROVIDE SCATTERED TO NUMEROUS
THUNDERSTORMS THROUGH MIDWEEK. SOME STORMS WILL PRODUCE GUSTY WINDS
AND HEAVY RAINFALL. A VERY MODEST DRYING TREND WILL THEN OCCUR
DURING THE LATTER PART OF THE WEEK AND INTO THIS WEEKEND. HOWEVER...
ENOUGH MOISTURE WILL EXIST FOR ISOLATED TO SCATTERED THUNDERSTORMS.
BELOW NORMAL DAYTIME TEMPERATURES WILL PREVAIL THROUGH WEDNESDAY
FOLLOWED BY A GRADUAL WARMING TREND LATER THIS WEEK.

&&

.DISCUSSION...ISOLATED SHOWERS/TSTMS MAINLY NEAR THE MOUNTAINS THIS
AFTERNOON SHOULD EVENTUALLY MOVE INTO THE LOWER ELEVATIONS THIS
EVENING. THE 18/12Z UNIV OF AZ WRF-NAM COMP REFLECTIVITY/10M WIND
SIGNATURES SUGGESTED A STRONG POTENTIAL FOR A HABOOB TO OCCUR THIS
EVENING ALONG THE I-10 CORRIDOR FROM TUCSON TO PHOENIX. HOWEVER...
THESE SIGNATURES WERE NOT NEARLY AS APPARENT VIA THE 18/12Z UNIV OF
AZ WRF-GFS AND THE LOCAL WFO WRF MODELS. GIVEN THESE DIFFERENCES...
HAVE OPTED TO NOT ISSUE A BLOWING DUST ADVISORY FOR LOCALES NW OF
TUCSON THIS EVENING. HOWEVER...HAVE DEPICTED AREAS OF BLOWING DUST
IN SOUTH CENTRAL PINAL COUNTY THIS EVENING.

HIGH PRESSURE ALOFT CENTERED OVER NWRN NEW MEXICO THIS AFTERNOON
WILL BECOME POSITIONED OVER THE LOWER MISSISSIPPI RIVER VALLEY
REGION BY WED AS A CLOSED UPPER LOW DEVELOPS OVER SRN CALIFORNIA. A
STRONGLY DIFFLUENT FLOW ALOFT REGIME IN COMBINATION WITH AMPLE
MOISTURE SHOULD ENHANCE COVERAGE OF SHOWERS/TSTMS LATER TONIGHT INTO
TUE. POPS WERE INCREASED TO DEPICT SCATTERED TO NUMEROUS COVERAGE OF
SHOWERS/TSTMS BY TUE AFTERNOON.

THERE IS STILL SOME UNCERTAINTY REGARDING THE EXACT PERIOD FOR THE
HEAVIEST RAINFALL TO OCCUR. ALTHOUGH STORM MOTIONS MAY BE RELATIVELY
FAST...THE PROGGED PATTERN SUGGESTS THAT TRAINING STORMS THAT WOULD
ENHANCE HEAVY RAINFALL MAY OCCUR. AT ANY RATE...HAVE DEFERRED A
POTENTIAL FLASH FLOOD WATCH ISSUANCE TO SUBSEQUENT SHIFTS. SOMEWHAT
LESS COVERAGE OF SHOWERS/TSTMS SHOULD OCCUR WED VERSUS TUE.
HOWEVER...CONTINUED AMPLE MOISTURE IN COMBINATION WITH A SOMEWHAT
DIFFLUENT FLOW ALOFT REGIME AHEAD OF THE SRN CALIFORNIA UPPER LOW
WILL PROVIDE SCATTERED SHOWERS/TSTMS ACROSS MUCH OF SE AZ.

18/12Z GFS/ECMWF WERE SIMILAR WITH SHUNTING THE DEEPER MOISTURE EWD
INTO WRN NEW MEXICO THUR AS THE SRN CALIFORNIA UPPER LOW BEGINS TO
MERGE WITH THE NRN STREAM TROUGH. A VERY GRADUAL DRYING TREND IS
PROGGED TO OCCUR FRI-SAT UNDER LIGHT GENERALLY WLY FLOW ALOFT.
GFS/ECMWF WERE SIMILAR WITH DEPICTING INCREASED MOISTURE SUN AS THE
MID-LEVEL FLOW BECOMES ELY AND A WEAK UPPER LOW APPROACHES FROM THE
SOUTH. THE UPSHOT FOR THUR-SUN...ENOUGH MOISTURE WILL EXIST FOR
ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING SHOWERS/TSTMS.

HIGH TEMPS TUE-WED ARE FORECAST TO AVERAGE ABOUT 5-8 DEGS F OR SO
BELOW NORMAL. A WARMING TREND IS ON TAP DURING THE LATTER PART OF
THE WEEK...WITH DAYTIME TEMPS RETURNING CLOSE TO NORMAL THIS
UPCOMING WEEKEND.

&&

.AVIATION...VALID THRU 20/00Z.
EXPECT SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS THROUGH
TUESDAY AFTERNOON. MVFR VISIBILITIES AND BRIEF WIND GUSTS OF 45-50
KTS WILL OCCUR WITH THE STRONGER TSRA. OTHERWISE...CLOUD DECKS WILL
MAINLY BE AT 6-12K FT AGL AND SURFACE WIND WILL GENERALLY BE LESS
THAN 10 KTS THRU TUESDAY AFTERNOON. AVIATION DISCUSSION NOT UPDATED
FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...SCATTERED TO NUMEROUS THUNDERSTORMS WILL OCCUR
THROUGH WEDNESDAY AS AMPLE MOISTURE REMAINS ACROSS SOUTHEAST
ARIZONA. THE STRONGER THUNDERSTORMS WILL PRODUCE STRONG...GUSTY AND
ERRATIC WINDS. EXPECT SOMEWHAT LESS COVERAGE OF THUNDERSTORMS DURING
THE LATTER PART OF THE WEEK AND NEXT WEEK. HOWEVER...MOISTURE WILL
BE SUFFICIENT TO PROVIDE ISOLATED TO SCATTERED MAINLY AFTERNOON AND
EVENING THUNDERSTORMS. OTHERWISE...20-FOOT WINDS WILL EXHIBIT NORMAL
DIURNAL TRENDS AND BE MOSTLY LESS THAN 15 MPH.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

FRANCIS






000
FXUS65 KTWC 182122
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
220 PM MST MON AUG 18 2014

.SYNOPSIS...AMPLE MOISTURE WILL PROVIDE SCATTERED TO NUMEROUS
THUNDERSTORMS THROUGH MIDWEEK. SOME STORMS WILL PRODUCE GUSTY WINDS
AND HEAVY RAINFALL. A VERY MODEST DRYING TREND WILL THEN OCCUR
DURING THE LATTER PART OF THE WEEK AND INTO THIS WEEKEND. HOWEVER...
ENOUGH MOISTURE WILL EXIST FOR ISOLATED TO SCATTERED THUNDERSTORMS.
BELOW NORMAL DAYTIME TEMPERATURES WILL PREVAIL THROUGH WEDNESDAY
FOLLOWED BY A GRADUAL WARMING TREND LATER THIS WEEK.

&&

.DISCUSSION...ISOLATED SHOWERS/TSTMS MAINLY NEAR THE MOUNTAINS THIS
AFTERNOON SHOULD EVENTUALLY MOVE INTO THE LOWER ELEVATIONS THIS
EVENING. THE 18/12Z UNIV OF AZ WRF-NAM COMP REFLECTIVITY/10M WIND
SIGNATURES SUGGESTED A STRONG POTENTIAL FOR A HABOOB TO OCCUR THIS
EVENING ALONG THE I-10 CORRIDOR FROM TUCSON TO PHOENIX. HOWEVER...
THESE SIGNATURES WERE NOT NEARLY AS APPARENT VIA THE 18/12Z UNIV OF
AZ WRF-GFS AND THE LOCAL WFO WRF MODELS. GIVEN THESE DIFFERENCES...
HAVE OPTED TO NOT ISSUE A BLOWING DUST ADVISORY FOR LOCALES NW OF
TUCSON THIS EVENING. HOWEVER...HAVE DEPICTED AREAS OF BLOWING DUST
IN SOUTH CENTRAL PINAL COUNTY THIS EVENING.

HIGH PRESSURE ALOFT CENTERED OVER NWRN NEW MEXICO THIS AFTERNOON
WILL BECOME POSITIONED OVER THE LOWER MISSISSIPPI RIVER VALLEY
REGION BY WED AS A CLOSED UPPER LOW DEVELOPS OVER SRN CALIFORNIA. A
STRONGLY DIFFLUENT FLOW ALOFT REGIME IN COMBINATION WITH AMPLE
MOISTURE SHOULD ENHANCE COVERAGE OF SHOWERS/TSTMS LATER TONIGHT INTO
TUE. POPS WERE INCREASED TO DEPICT SCATTERED TO NUMEROUS COVERAGE OF
SHOWERS/TSTMS BY TUE AFTERNOON.

THERE IS STILL SOME UNCERTAINTY REGARDING THE EXACT PERIOD FOR THE
HEAVIEST RAINFALL TO OCCUR. ALTHOUGH STORM MOTIONS MAY BE RELATIVELY
FAST...THE PROGGED PATTERN SUGGESTS THAT TRAINING STORMS THAT WOULD
ENHANCE HEAVY RAINFALL MAY OCCUR. AT ANY RATE...HAVE DEFERRED A
POTENTIAL FLASH FLOOD WATCH ISSUANCE TO SUBSEQUENT SHIFTS. SOMEWHAT
LESS COVERAGE OF SHOWERS/TSTMS SHOULD OCCUR WED VERSUS TUE.
HOWEVER...CONTINUED AMPLE MOISTURE IN COMBINATION WITH A SOMEWHAT
DIFFLUENT FLOW ALOFT REGIME AHEAD OF THE SRN CALIFORNIA UPPER LOW
WILL PROVIDE SCATTERED SHOWERS/TSTMS ACROSS MUCH OF SE AZ.

18/12Z GFS/ECMWF WERE SIMILAR WITH SHUNTING THE DEEPER MOISTURE EWD
INTO WRN NEW MEXICO THUR AS THE SRN CALIFORNIA UPPER LOW BEGINS TO
MERGE WITH THE NRN STREAM TROUGH. A VERY GRADUAL DRYING TREND IS
PROGGED TO OCCUR FRI-SAT UNDER LIGHT GENERALLY WLY FLOW ALOFT.
GFS/ECMWF WERE SIMILAR WITH DEPICTING INCREASED MOISTURE SUN AS THE
MID-LEVEL FLOW BECOMES ELY AND A WEAK UPPER LOW APPROACHES FROM THE
SOUTH. THE UPSHOT FOR THUR-SUN...ENOUGH MOISTURE WILL EXIST FOR
ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING SHOWERS/TSTMS.

HIGH TEMPS TUE-WED ARE FORECAST TO AVERAGE ABOUT 5-8 DEGS F OR SO
BELOW NORMAL. A WARMING TREND IS ON TAP DURING THE LATTER PART OF
THE WEEK...WITH DAYTIME TEMPS RETURNING CLOSE TO NORMAL THIS
UPCOMING WEEKEND.

&&

.AVIATION...VALID THRU 20/00Z.
EXPECT SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS THROUGH
TUESDAY AFTERNOON. MVFR VISIBILITIES AND BRIEF WIND GUSTS OF 45-50
KTS WILL OCCUR WITH THE STRONGER TSRA. OTHERWISE...CLOUD DECKS WILL
MAINLY BE AT 6-12K FT AGL AND SURFACE WIND WILL GENERALLY BE LESS
THAN 10 KTS THRU TUESDAY AFTERNOON. AVIATION DISCUSSION NOT UPDATED
FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...SCATTERED TO NUMEROUS THUNDERSTORMS WILL OCCUR
THROUGH WEDNESDAY AS AMPLE MOISTURE REMAINS ACROSS SOUTHEAST
ARIZONA. THE STRONGER THUNDERSTORMS WILL PRODUCE STRONG...GUSTY AND
ERRATIC WINDS. EXPECT SOMEWHAT LESS COVERAGE OF THUNDERSTORMS DURING
THE LATTER PART OF THE WEEK AND NEXT WEEK. HOWEVER...MOISTURE WILL
BE SUFFICIENT TO PROVIDE ISOLATED TO SCATTERED MAINLY AFTERNOON AND
EVENING THUNDERSTORMS. OTHERWISE...20-FOOT WINDS WILL EXHIBIT NORMAL
DIURNAL TRENDS AND BE MOSTLY LESS THAN 15 MPH.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

FRANCIS







000
FXUS65 KTWC 181610
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
910 AM MST MON AUG 18 2014

.SYNOPSIS...AMPLE MOISTURE WILL PROVIDE SCATTERED TO NUMEROUS
THUNDERSTORMS THIS WEEK. SOME STORMS WILL PRODUCE GUSTY WINDS AND
HEAVY HEAVY RAIN THAT MAY PRODUCE FLASH FLOODING. DAYTIME
TEMPERATURES WILL BE BELOW AVERAGE BY MIDWEEK.

&&

.DISCUSSION...IR/VISIBLE SATELLITE IMAGERY AND SURFACE OBSERVATIONS
INDICATE PARTLY CLOUDY SKIES ACROSS ERN SECTIONS TO CLOUDY SKIES
ACROSS WRN PIMA COUNTY. DEWPOINTS AT LOWER ELEVATIONS VALID 16Z
RANGED FROM THE UPPER 50S-MID 60S F...AND THESE TEMPS WERE NEARLY
IDENTICAL TO 24 HOURS AGO. SURFACE TEMPS WERE GENERALLY 2-6 DEGS F
COOLER VERSUS THIS TIME SUN.

18/12Z KTWC SOUNDING TOTAL PRECIP WATER VALUE WAS 1.51 INCHES. A
FAIRLY UNSTABLE ENVIRONMENT EXISTED WITH LIFTED INDEX OF MINUS 6 AND
UNMODIFIED SURFACE-BASED CAPE OF 1639 J/KG. HAVE NOTED THE
CONSIDERABLY STRONGER MID-LEVEL SELY STEERING FLOW FOR THUNDERSTORMS
VERSUS THE PAST 2-3 DAYS. 18/12Z UPPER AIR PLOTS DEPICTED A BROAD
RIDGE OVER THE SWRN CONUS WITH 591 DM HIGH PRESSURE CENTERED OVER
THE FOUR CORNERS REGION. LIGHT TO MODERATE GENERALLY ELY/SELY FLOW
PREVAILED IN THE SURFACE-400 MB LAYER WITH MODERATE WLY FLOW ABOVE
400 MB.

18/14Z RUC HRRR...18/12Z NAM AND 18/12Z UNIV OF AZ WRF-NAM WERE
SIMILAR WITH DEVELOPING SHOWERS/TSTMS BY EARLY THIS AFTERNOON MOSTLY
NEAR THE INTERNATIONAL BORDER ADJACENT SANTA CRUZ/COCHISE COUNTIES.
SHOWERS/TSTMS ARE THEN PROGGED TO MOVE NWWD INTO SOUTH CENTRAL AZ BY
AROUND MIDNIGHT TONIGHT. THIS SCENARIO SEEMS QUITE VIABLE GIVEN THE
AFOREMENTIONED STRONGER MID-LEVEL STORM STEERING FLOW AS OBSERVED
VIA THE 18/12Z KTWC SOUNDING.

BASED ON THESE SOLUTIONS AS WELL AS COORD WITH WFO PSR...HAVE OPTED
TO INCREASE THE INHERITED POPS FOR THIS AFTERNOON THRU TUE. BASED ON
THE COMP REFLECTIVITY/10M WIND SIGNATURES AS PER THE UNIV OF AZ
WRF-NAM...HAVE ADDED AREAS OF BLOWING DUST FOR SOUTH CENTRAL PINAL
COUNTY /AZZ505/ THIS EVENING. MAY OPT TO ISSUE A BLOWING DUST
ADVISORY LATER TODAY FOR SOUTH CENTRAL PINAL COUNTY IF SUBSEQUENT
RUC HRRR AND UNIV OF AZ WRF-GFS SOLUTIONS MIMIC THE UNIV OF AZ
WRF-NAM SOLUTION.

ALSO...BASED THUS FAR ON THE 18/12Z NAM...AM GIVING CONSIDERATION
TOWARD THE POTENTIAL ISSUANCE OF A FLASH FLOOD WATCH MAINLY FOR
LOCALES EAST OF TUCSON TUE. WILL ADDRESS THIS NOTION FURTHER IN THE
AFTERNOON DISCUSSION. OTHERWISE...HIGH TEMPS THIS AFTERNOON SHOULD
AVERAGE ABOUT 3-5 DEGS F COOLER VERSUS TEMPS ACHIEVED SUN.

PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.

&&

.AVIATION...VALID THRU 19/18Z.
EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP SOUTHEAST-TO-
SOUTHWEST OF KTUS BY EARLY THIS AFTERNOON. SCATTERED TO NUMEROUS
-TSRA/-SHRA WILL THEN OCCUR THIS AFTERNOON AND THIS EVENING. MVFR
VISIBILITIES AND BRIEF WIND GUSTS OF 45-50 KTS WILL OCCUR WITH THE
STRONGER TSRA. SCATTERED -SHRA AND ISOLATED -TSRA WILL PREVAIL LATE
TONIGHT INTO TUESDAY MORNING. OTHERWISE...CLOUD DECKS WILL MAINLY BE
AT 6-12K FT AGL AND SURFACE WIND GENERALLY BE LESS THAN 10 KTS THRU
TUESDAY MORNING. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...SCATTERED TO NUMEROUS THUNDERSTORMS WILL OCCUR THIS
WEEK AS AMPLE MOISTURE REMAINS ACROSS SOUTHEAST ARIZONA. THE
STRONGER THUNDERSTORMS WILL PRODUCE STRONG...GUSTY AND ERRATIC
WINDS. OTHERWISE...AFTERNOON MINIMUM RELATIVE HUMIDITIES ARE
FORECAST TO BE MOSTLY IN THE 25-50 PERCENT RANGE AT LOWER ELEVATIONS
FOLLOWED BY GOOD TO EXCELLENT OVERNIGHT RECOVERIES. 20-FOOT WINDS
WILL EXHIBIT NORMAL DIURNAL TRENDS AND BE MOSTLY LESS THAN 15 MPH.

&&

.PREV DISCUSSION...WEDNESDAY...UPPER LOW IS FORECAST TO BE ALONG OR
JUST OFF THE SRN CA CST. MOIST SOUTHERLY FLOW CONTINUES ACROSS SRN
AZ...BUT COULD ALSO SEE SOME DRIER AIR PUSH INTO THE SWRN PART OF
THE STATE. WILL CONTINUE CHANCE OF AFTERNOON/EVENING STORMS.
DEPENDING ON HOW MUCH RAIN FALLS ON TUESDAY WILL HAVE A PART IN
DETERMINING HOW WARM IT WILL GET. 00Z MOS GUIDANCE COOLER THAN WHAT
WE ARE FORECASTING. AGAIN WILL NOT MAKE ANY CHANGES HERE.

THURSDAY INTO THE UPCOMING WEEKEND...STILL SOME UNCERTAINTY OF WHEN
OR IF THE SRN CA UPPER LOW WILL LIFT THRU THE STATE. GFS SAYS
THURSDAY...ECMWF SAYS FRIDAY...CANADIAN KEEPS IT OFFSHORE. WITH SUCH
UNCERTAINTY...WILL MAINTAIN NEAR CLIMO POPS DURING THIS PERIOD.

OVERALL STILL SHAPING UP TO BE A WET WEEK ACROSS SE AZ WITH FLASH
FLOODING A CONCERN MOST OF THE WEEK.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

FRANCIS
PREVIOUS DISCUSSION...GLUECK







000
FXUS65 KTWC 181610
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
910 AM MST MON AUG 18 2014

.SYNOPSIS...AMPLE MOISTURE WILL PROVIDE SCATTERED TO NUMEROUS
THUNDERSTORMS THIS WEEK. SOME STORMS WILL PRODUCE GUSTY WINDS AND
HEAVY HEAVY RAIN THAT MAY PRODUCE FLASH FLOODING. DAYTIME
TEMPERATURES WILL BE BELOW AVERAGE BY MIDWEEK.

&&

.DISCUSSION...IR/VISIBLE SATELLITE IMAGERY AND SURFACE OBSERVATIONS
INDICATE PARTLY CLOUDY SKIES ACROSS ERN SECTIONS TO CLOUDY SKIES
ACROSS WRN PIMA COUNTY. DEWPOINTS AT LOWER ELEVATIONS VALID 16Z
RANGED FROM THE UPPER 50S-MID 60S F...AND THESE TEMPS WERE NEARLY
IDENTICAL TO 24 HOURS AGO. SURFACE TEMPS WERE GENERALLY 2-6 DEGS F
COOLER VERSUS THIS TIME SUN.

18/12Z KTWC SOUNDING TOTAL PRECIP WATER VALUE WAS 1.51 INCHES. A
FAIRLY UNSTABLE ENVIRONMENT EXISTED WITH LIFTED INDEX OF MINUS 6 AND
UNMODIFIED SURFACE-BASED CAPE OF 1639 J/KG. HAVE NOTED THE
CONSIDERABLY STRONGER MID-LEVEL SELY STEERING FLOW FOR THUNDERSTORMS
VERSUS THE PAST 2-3 DAYS. 18/12Z UPPER AIR PLOTS DEPICTED A BROAD
RIDGE OVER THE SWRN CONUS WITH 591 DM HIGH PRESSURE CENTERED OVER
THE FOUR CORNERS REGION. LIGHT TO MODERATE GENERALLY ELY/SELY FLOW
PREVAILED IN THE SURFACE-400 MB LAYER WITH MODERATE WLY FLOW ABOVE
400 MB.

18/14Z RUC HRRR...18/12Z NAM AND 18/12Z UNIV OF AZ WRF-NAM WERE
SIMILAR WITH DEVELOPING SHOWERS/TSTMS BY EARLY THIS AFTERNOON MOSTLY
NEAR THE INTERNATIONAL BORDER ADJACENT SANTA CRUZ/COCHISE COUNTIES.
SHOWERS/TSTMS ARE THEN PROGGED TO MOVE NWWD INTO SOUTH CENTRAL AZ BY
AROUND MIDNIGHT TONIGHT. THIS SCENARIO SEEMS QUITE VIABLE GIVEN THE
AFOREMENTIONED STRONGER MID-LEVEL STORM STEERING FLOW AS OBSERVED
VIA THE 18/12Z KTWC SOUNDING.

BASED ON THESE SOLUTIONS AS WELL AS COORD WITH WFO PSR...HAVE OPTED
TO INCREASE THE INHERITED POPS FOR THIS AFTERNOON THRU TUE. BASED ON
THE COMP REFLECTIVITY/10M WIND SIGNATURES AS PER THE UNIV OF AZ
WRF-NAM...HAVE ADDED AREAS OF BLOWING DUST FOR SOUTH CENTRAL PINAL
COUNTY /AZZ505/ THIS EVENING. MAY OPT TO ISSUE A BLOWING DUST
ADVISORY LATER TODAY FOR SOUTH CENTRAL PINAL COUNTY IF SUBSEQUENT
RUC HRRR AND UNIV OF AZ WRF-GFS SOLUTIONS MIMIC THE UNIV OF AZ
WRF-NAM SOLUTION.

ALSO...BASED THUS FAR ON THE 18/12Z NAM...AM GIVING CONSIDERATION
TOWARD THE POTENTIAL ISSUANCE OF A FLASH FLOOD WATCH MAINLY FOR
LOCALES EAST OF TUCSON TUE. WILL ADDRESS THIS NOTION FURTHER IN THE
AFTERNOON DISCUSSION. OTHERWISE...HIGH TEMPS THIS AFTERNOON SHOULD
AVERAGE ABOUT 3-5 DEGS F COOLER VERSUS TEMPS ACHIEVED SUN.

PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.

&&

.AVIATION...VALID THRU 19/18Z.
EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP SOUTHEAST-TO-
SOUTHWEST OF KTUS BY EARLY THIS AFTERNOON. SCATTERED TO NUMEROUS
-TSRA/-SHRA WILL THEN OCCUR THIS AFTERNOON AND THIS EVENING. MVFR
VISIBILITIES AND BRIEF WIND GUSTS OF 45-50 KTS WILL OCCUR WITH THE
STRONGER TSRA. SCATTERED -SHRA AND ISOLATED -TSRA WILL PREVAIL LATE
TONIGHT INTO TUESDAY MORNING. OTHERWISE...CLOUD DECKS WILL MAINLY BE
AT 6-12K FT AGL AND SURFACE WIND GENERALLY BE LESS THAN 10 KTS THRU
TUESDAY MORNING. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...SCATTERED TO NUMEROUS THUNDERSTORMS WILL OCCUR THIS
WEEK AS AMPLE MOISTURE REMAINS ACROSS SOUTHEAST ARIZONA. THE
STRONGER THUNDERSTORMS WILL PRODUCE STRONG...GUSTY AND ERRATIC
WINDS. OTHERWISE...AFTERNOON MINIMUM RELATIVE HUMIDITIES ARE
FORECAST TO BE MOSTLY IN THE 25-50 PERCENT RANGE AT LOWER ELEVATIONS
FOLLOWED BY GOOD TO EXCELLENT OVERNIGHT RECOVERIES. 20-FOOT WINDS
WILL EXHIBIT NORMAL DIURNAL TRENDS AND BE MOSTLY LESS THAN 15 MPH.

&&

.PREV DISCUSSION...WEDNESDAY...UPPER LOW IS FORECAST TO BE ALONG OR
JUST OFF THE SRN CA CST. MOIST SOUTHERLY FLOW CONTINUES ACROSS SRN
AZ...BUT COULD ALSO SEE SOME DRIER AIR PUSH INTO THE SWRN PART OF
THE STATE. WILL CONTINUE CHANCE OF AFTERNOON/EVENING STORMS.
DEPENDING ON HOW MUCH RAIN FALLS ON TUESDAY WILL HAVE A PART IN
DETERMINING HOW WARM IT WILL GET. 00Z MOS GUIDANCE COOLER THAN WHAT
WE ARE FORECASTING. AGAIN WILL NOT MAKE ANY CHANGES HERE.

THURSDAY INTO THE UPCOMING WEEKEND...STILL SOME UNCERTAINTY OF WHEN
OR IF THE SRN CA UPPER LOW WILL LIFT THRU THE STATE. GFS SAYS
THURSDAY...ECMWF SAYS FRIDAY...CANADIAN KEEPS IT OFFSHORE. WITH SUCH
UNCERTAINTY...WILL MAINTAIN NEAR CLIMO POPS DURING THIS PERIOD.

OVERALL STILL SHAPING UP TO BE A WET WEEK ACROSS SE AZ WITH FLASH
FLOODING A CONCERN MOST OF THE WEEK.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

FRANCIS
PREVIOUS DISCUSSION...GLUECK






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