Area Forecast Discussion
Issued by NWS Tucson, AZ

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FXUS65 KTWC 291641
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
941 AM MST WED JUL 29 2015

.SYNOPSIS...AN ELEVATED CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS
SOUTHEAST ARIZONA WILL CONTINUE THIS WEEK WITH SOME STORMS PRODUCING
LOCALLY HEAVY RAIN AND STRONG WINDS. RAIN CHANCES WILL CONTINUE OVER
THE WEEKEND...BUT COVERAGE WILL DECREASE WITH A WEAKER FLOW AS HIGH
PRESSURE INCREASES ALOFT.

&&

.DISCUSSION...WATER VAPOR IMAGERY AND 29/12Z UPPER-AIR PLOTS SHOW A
RIDGE CENTERED OVER THE MID MISSISSIPPI RIVER VALLEY...WHILE AN
UPPER LOW RESIDES OFF THE WEST COAST OF THE SOUTH CENTRAL BAJA
PENINSULA. IR SATELLITE IMAGERY SHOWS EXTENSIVE DEBRIS CLOUDS FROM
YESTERDAY AND LAST NIGHTS CONVECTION COVERING MUCH OF ARIZONA...
NORTHERN SONORA AND CHIHUAHUA...AS WELL AS WESTERN NEW MEXICO.
VISIBLE SATELLITE IMAGERY SHOWS AN MCV OVER EXTREME WESTERN PIMA
COUNTY JUST WEST OF AJO. MEANWHILE...ANOTHER MCV IS IN THE GENERAL
VICINITY OF EXTREME SOUTHWESTERN NEW MEXICO NEAR LORDSBURG.

RADAR MOSAIC SHOWS LINGERING LIGHT SHOWERS MAINLY WEST OF
INTERSTATES 10 AND 19 THAT EXTEND FROM NEAR AVRA VALLEY TO NEAR
THREE POINTS TO NEAR ARIVACA AND SOUTHEAST INTO PORTIONS OF SANTA
CRUZ COUNTY.

WITH SIGNIFICANT ACTIVITY YESTERDAY AND OVERNIGHT WE WILL LIKELY GET
TO A SLOW START THIS AFTERNOON. FAVORED AREAS WILL BE THOSE
LOCATIONS THAT SEE MORE SUN...AND AT THAT THIS TIME THAT LOOKS TO BE
OVER PORTIONS OF GREENLEE...GRAHAM AND COCHISE COUNTIES.

BETTER FLOW ON THIS MORNINGS KTWC 12Z SOUNDING WITH STEERING FLOW OF
AROUND 15 TO 20 MPH. STILL A MOIST SOUNDING...SO WHAT STORMS DO
DEVELOP TODAY...MAINLY LATE IN THE AFTERNOON...WILL BE CAPABLE OF
PRODUCING BRIEF PERIODS OF HEAVY RAIN...BUT WITH MUCH FASTER MOTION
TO THE STORMS COMPARED TO YESTERDAY...FLOODING ISSUES NOT AS
PREVALENT AS THEY WERE YESTERDAY...BUT STILL A CONCERN. WE COULD
ALSO SEE STRONG GUSTY WINDS WITH THE STRONGER STORMS THAT DEVELOP
TODAY.

INHERITED POP FORECAST HAS SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS IN THE FORECAST FOR THIS MORNING AND INTO THE
AFTERNOON...WITH A BETTER CHANCE LATE THIS AFTERNOON AND INTO THE
EVENING HOURS AS THE DEBRIS CLOUDS WILL HAVE MORE OF AN OPPORTUNITY
TO BURN OFF AND EXPOSE MORE SUN AT THAT TIME. SO...FOR NOW...NO
CHANGES TO THE FORECAST FOR THE REST OF TODAY...BUT WILL CONTINUE TO
MONITOR SATELLITE AND RADAR TRENDS THROUGHOUT THE DAY AND WILL MAKE
ADJUSTMENTS AS NEEDED.

FOR DETAILS REGARDING THE FORECAST BEYOND TODAY...PLEASE REFER TO
THE PREVIOUS DISCUSSION BELOW.

&&

.AVIATION...VALID THRU 30/18Z.
SCT-BKN CLOUDS AT 8-12K FT AGL AND BKN-OVC CLOUDS AT 15-20K FT AGL
WITH RESIDUAL -SHRA/-TSRA THIS MORNING. SCT-NUMEROUS SHRA/TSRA
DEVELOPING AGAIN AFT 29/22Z THROUGH ABOUT 30/04Z. MVFR CONDITIONS
AND VRB WIND GUSTS TO 40 KTS POSSIBLE IN AND AROUND THE STRONGER
TSRA. OUTSIDE OF STORM INFLUENCES...SFC WINDS WILL GENERALLY BE LESS
THAN 12 KTS WITH A FEW HIGHER GUSTS IN THE AFTERNOON/EARLY EVENING
HOURS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...PLENTY OF MOISTURE FOR A CONTINUED CHANCE OF SHOWERS
AND THUNDERSTORMS. STRONG OUTFLOW WINDS WILL BE POSSIBLE NEAR
THUNDERSTORMS...WITH WIND GUSTS BETWEEN 40 AND 45 MPH. OTHERWISE...
20-FT WINDS WILL GENERALLY BE TERRAIN DRIVEN AND LESS THAN 15
MPH...WITH SOME AFTERNOON AND EARLY EVENING BREEZINESS DUE TO THE
STRONG DAYTIME HEATING.

&&

.PREV DISCUSSION...BY THURSDAY THE LOW TO OUR SOUTHWEST WILL HAVE
LIFTED OUT OF THE PICTURE...BUT THE SOUTHERLY TO SOUTHEASTERLY FLOW
WILL REMAIN...IF PERHAPS A BIT WEAKER. WE SHOULD CONTINUE TO SEE A
CHANCE OF STORMS WITH MORE TYPICAL DIURNAL TRENDS. WE`LL HAVE TO SEE
HOW BUSY TONIGHT AND THURSDAY MORNING ARE. A WEAKER FLOW GENERALLY
MEANS THE ATMOSPHERE WILL TAKE LONGER TO RESET.

AFTER THAT WE WILL KEEP SOME FLAVOR OF MONSOONAL FLOW BUT NOT AT AN
INTENSITY THAT WILL FAVOR ORGANIZED CONVECTION. WE`LL KEEP THE
FORECAST AT CLIMATOLOGY OVER THE WEEKEND INTO EARLY NEXT WEEK AND
KEEP AN EYE OUT FOR UP/DOWN DETAILS AS MINOR FEATURES IN THE FLOW
PRESENT THEMSELVES.

&&

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

&&

$$

CURRENT DISCUSSION...MOLLERE
PREVIOUS DISCUSSION...MEYER/RASMUSSEN

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