Area Forecast Discussion
Issued by NWS Tucson, AZ

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS65 KTWC 051706
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
1005 AM MST SUN JUL 5 2015

.SYNOPSIS...SOUTHEAST ARIZONA WILL EXPERIENCE AN UPSWING IN SHOWERS
AND THUNDERSTORMS TODAY WITH LOCALLY HEAVY RAINFALL POSSIBLE. RAIN
CHANCES WILL DECREASE AS A LOW PRESSURE SYSTEM APPROACHES CENTRAL
CALIFORNIA. DAYTIME TEMPERATURES WILL REMAIN CLOSE TO SEASONAL
NORMALS.

&&

.DISCUSSION...WATER VAPOR IMAGERY AND 05/12Z UPPER-AIR PLOTS SHOW A
RIDGE CENTERED OVER EASTERN NEW MEXICO. MEANWHILE...A PACIFIC LOW
PRESSURE SYSTEM IS SPINNING WELL WEST OF THE SOUTHERN CALIFORNIA
COAST. A SWATH OF DRY MID TO UPPER LEVEL AIR CAN BE SEEN OVER THE
EASTERN PACIFIC WATERS...THE BAJA PENINSULA...NORTHWESTERN SONORA
AND ACROSS PARTS OF SOUTHERN CALIFORNIA AND INTO WESTERN ARIZONA.
MEANWHILE...VISIBLE SATELLITE IMAGERY AND RADAR MOSAIC FROM AROUND
THE REGION SHOW ANOTHER MCV THAT HAS DEVELOPED AS A RESULT OF LAST
NIGHTS CONVECTION...WITH THE CENTER OF THIS FEATURE NEAR BISBEE.

IR AND VISIBLE SATELLITE IMAGERY SHOW EXTENSIVE CLOUDINESS COVERING
THE SOUTHEASTERN HALF OF THE STATE GENERALLY FROM YUMA TO PRESCOTT
TO TUBA CITY. RADAR MOSAIC IS SHOWING VERY LIGHT RETURNS ACROSS
AREAS EAST OF TUCSON TOWARD THE NEW MEXICO BORDER...MORE
SPECIFICALLY OVER COCHISE COUNTY. THIS IS CLOSE TO THE PREVIOUSLY
MENTIONED MCV NEAR BISBEE. ON THE OPPOSITE END OF THE FORECAST
AREA...OVER WESTERN PIMA COUNTY IN THE VICINITY OF AJO AND ORGAN
PIPE NATIONAL MONUMENT...ISOLATED SHOWERS AND THUNDERSTORMS HAVE
DEVELOPED...WHICH IS NEAR THE INTERFACE OF THE DRY AIR TO THE WEST
AND THE MOIST AIR TO THE EAST. THIS INTERFACE TYPICALLY BECOMES A
BATTLE ZONE FOR CONVECTIVE DEVELOPMENT AND EXPECT TO SEE THIS
CONTINUE THROUGHOUT THE AFTERNOON HOURS TODAY. UNCERTAIN AS TO THE
AFFECT THE MCV WILL HAVE ON PORTIONS OF THE CWA THIS AFTERNOON.
YESTERDAYS MCV TENDED TO SUPPRESS ACTIVITY...AT LEAST NEAR THE
IMMEDIATE PROXIMITY OF THE CIRCULATION. HOWEVER...THE 12Z RUN OF THE
U OF A WRF/NAM DOES SHOW THE ACTIVITY THIS AFTERNOON TO BE SOMEWHAT
LIMITED OVER COCHISE COUNTY...BUT IT ALSO DOES NOT INITIALIZE THE
CONVECTION THAT IS CURRENTLY ONGOING OVER WESTERN PIMA COUNTY.
DURING THE AFTERNOON IT SHOWS A FAIRLY ACTIVE DAY ACROSS THE CENTRAL
PORTION OF MY FORECAST AREA...INCLUDING THE TUCSON METRO AND VERY
ACTIVE OVER THE TOHONO O`ODHAM NATION. THE 06Z RUN OF THE WRF/GFS
DID NOT INITIALIZE THE CONVECTION OUT WEST AND SHOWS MORE LIMITED
ACTIVITY COMPARED TO THE WRF/NAM. THAT SAID...I INCREASED POPS A BIT
OUT WEST AND DECREASED POPS OVER COCHISE COUNTY FOR THIS AFTERNOON.

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

&&

.AVIATION...VALID THRU 06/18Z.
ISOLD -SHRA/TS MAINLY OVER FAR WESTERN PIMA COUNTY THIS AM. SCTD
-TSRA/-SHRA DVLPG THIS AFTN INTO THIS EVENING. BRIEF WIND GUSTS OF
40-45 KTS MAY ACCOMPANY THE STRONGER TSRA. OTHERWISE...CLOUD DECKS
WILL MAINLY BE AT OR ABOVE 10K FT AGL AND SURFACE WIND WILL
GENERALLY BE LESS THAN 10 KTS. AVIATION DISCUSSION NOT UPDATED FOR
TAF AMENDMENTS.

&&

.FIRE WEATHER...SCATTERED SHOWERS AND THUNDERSTORMS WILL OCCUR
TODAY. THE MAIN IMPACT WILL BE THE COMBINATION OF BRIEF STRONG AND
GUSTY WINDS AND HEAVY RAINFALL. SOMEWHAT REDUCED COVERAGE OF SHOWERS
AND THUNDERSTORMS WILL BEGIN MONDAY. THEREAFTER...ADEQUATE MOISTURE
WILL MAINTAIN ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS
TUESDAY INTO NEXT SATURDAY. GENERALLY LIGHT TERRAIN DRIVEN WINDS
WILL PREVAIL OUTSIDE OF THUNDERSTORM INFLUENCES.

&&

.PREV DISCUSSION...LATEST MODELS CONTINUED TO SUGGEST AN UPSWING IN
SHOWER AND THUNDERSTORM ACTIVITY TODAY. THIS WAS MAINLY BASED ON A
DISTURBANCE TRACKING NORTHWARD IN THE SOUTHERLY FLOW AROUND THE
UPPER HIGH CENTERED OVER NEW MEXICO AND THE LOW PRESSURE SYSTEM
APPROACHING THE CALIFORNIA COAST. MODELS INDICATED A DECREASE IN
RAIN CHANCES AS DRIER AIR SPREADS IN FROM THE WEST IN ASSOCIATION
WITH THE LOW PRESSURE SYSTEM ENTERING CENTRAL CALIFORNIA BY
THURSDAY. DAYTIME TEMPERATURES WILL GRADUALLY LOWER AS THE LOW
PRESSURE SYSTEM ENTERS CALIFORNIA AND TRACKS THROUGH THE GREAT BASIN
THURSDAY INTO NEXT WEEKEND.

&&

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

&&

$$

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



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.