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000
FXUS65 KTWC 212107
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
207 PM MST MON JUL 21 2014

.SYNOPSIS...EXPECT ISOLATED TO SCATTERED THUNDERSTORMS MOSTLY EAST
AND SOUTH OF TUCSON THROUGH THE MIDDLE OF THIS WEEK. MUCH HOTTER
TEMPERATURES WILL OCCUR TUESDAY THROUGH THURSDAY...WITH NEAR RECORD
HIGHS POSSIBLE. AN INCREASE IN THUNDERSTORM ACTIVITY SHOULD OCCUR
LATE IN THE WEEK AND INTO THE WEEKEND.

&&

.DISCUSSION...WATER VAPOR IMAGERY AND 21/12Z UPPER-AIR PLOTS SHOW A
RIDGE CENTERED IN THE GENERAL VICINITY OF SOUTHEASTERN NEW MEXICO
AND THE TEXAS PANHANDLE. THIS IS RESULTING IN SOUTHWESTERLY FLOW IN
THE MID TO UPPER LEVELS OVER ARIZONA. FLOW FROM THE SFC-500MB WAS
GENERALLY VERY LIGHT AT 5 TO 10 KNOTS. VISIBLE SATELLITE IMAGERY
FROM EARLIER THIS MORNING SHOWED A NICE MCV OVER EXTREME NE SONORA
AND NW CHIHUAHUA MEXICO AS A RESULT OF THE COMPLEX THAT DEVELOPED
OVER SONORA MEXICO SUNDAY EVENING. CURRENTLY THIS MCV IS ALONG THE
ARIZONA/NEW MEXICO BORDER AND MOVING NORTH...BUT SHOULDN`T SURVIVE
FOR MUCH LONGER...BUT IS LIKELY ENHANCING SOME OF THE ACTIVITY IN
WESTERN NEW MEXICO. THE EXTENSIVE CLOUDINESS ASSOCIATED WITH THIS
MCV COVERED A LARGE SWATH ALONG THE AZ/NM BORDER AND WELL SOUTH INTO
NORTHERN MEXICO...BUT HAS MOSTLY ERODED THIS AFTERNOON WITH
CLOUDINESS ONLY LINGERING ACROSS EASTERN COCHISE AND EASTERN GRAHAM
COUNTIES AND MUCH OF GREENLEE COUNTY. A SMALL CUMULUS FIELD HAS
DEVELOPED OVER THE HIGHER TERRAIN SOUTH OF THE BORDER BETWEEN
NOGALES AND DOUGLAS DURING THE PAST COUPLE OF HOURS OR SO.

ONE SMALL CELL HAS DEVELOPED OVER THE CHIRICAHUA MOUNTAINS OF EAST
CENTRAL COCHISE COUNTY...WITH ADDITIONAL DEVELOPMENT JUST ALONG THE
COCHISE COUNTY BORDER WITH MEXICO AND FARTHER SOUTHEAST OVER THE
SIERRA MADRES IN WESTERN CHIHUAHUA MEXICO. THIS AFTERNOON AND
EVENING SHOULD BE SIMILAR TO YESTERDAY WITH CONVECTION DEVELOPING
MOSTLY TO THE SOUTH OVER NORTHERN MEXICO...WITH A FEW CELLS POSSIBLE
OVER PARTS OF SANTA CRUZ AND COCHISE COUNTIES.

TUESDAY SHOULD SEE A SLIGHT UPTICK IN THUNDERSTORM CHANCES AS THE
HIGH SHIFTS TO A POSITION OVER WESTERN COLORADO AND PWATS ARE
EXPECTED TO INCREASE TO AROUND 1.3 - 1.4 INCHES. BY WEDNESDAY THE
HIGH WILL BE OVER EASTERN COLORADO AND WESTERN KANSAS WITH THE RIDGE
AXIS NOSING INTO THE DESERT SOUTHWEST...RESULTING IN SIGNIFICANTLY
WARMER TEMPERATURES. PWATS WILL CONTINUE IN THE 1.2 - 1.6 INCH RANGE
FROM TUCSON TOWARD AJO...WITH LOWER VALUES ALONG THE NEW MEXICO
BORDER. GIVEN THAT...EXPECT AN EVEN BETTER CHANCE WEDNESDAY
AFTERNOON FOR MOST AREAS...EXCEPT FOR AREAS ALONG THE IMMEDIATE
BORDER WITH NEW MEXICO. BY THURSDAY ANOTHER DOWN SWING IN ACTIVITY
IS EXPECTED AS THE HIGH BECOMES CENTERED OVER EASTERN ARIZONA AND
MUCH OF NEW MEXICO...AND DRIER PWATS MOVE IN FROM THE EAST...WITH
READINGS BELOW THE 1 INCH MARK FROM TUCSON EASTWARD.

BY FRIDAY...BUT ESPECIALLY THIS WEEKEND...WE SHOULD SEE A FAIRLY
SIGNIFICANT INCREASE IN THUNDERSTORM ACTIVITY AS AN UPPER LEVEL
DISTURBANCE OVER NORTHERN MEXICO MOVES NORTHWEST ACROSS PARTS OF
SONORA...SOUTHERN ARIZONA AND NORTHERN BAJA...AND THE HIGH BECOMES
ORIENTED FROM SRN UTAH ACROSS NORTHEAST ARIZONA AND INTO NORTHERN
NEW MEXICO. THIS SETUP WILL GIVE ARIZONA A FAIRLY LONG EAST TO
SOUTHEASTERLY FETCH FOR ADDITIONAL MOISTURE TO SPILL INTO THE
REGION. THE HIGH TRANSITIONS OVER THE AZ/NM BORDER MONDAY FOR A
DECREASE IN ACTIVITY.

HIGH TEMPERATURES ABOVE NORMAL THROUGHOUT THE FORECAST PERIOD...BUT
THE WARMEST DAYS WILL OCCUR WEDNESDAY THROUGH FRIDAY...WHEN READINGS
WILL BE 8 TO 12 DEGS ABOVE NORMAL. OTHERWISE...EXPECT HIGHS TO BE 3
TO 6 DEGS ABOVE NORMAL. LOWS GENERALLY 4 TO 6 DEGS ABOVE NORMAL EACH
DAY...BUT THE WARMEST MORNINGS SHOULD OCCUR WEDNESDAY THROUGH
FRIDAY.

&&

.AVIATION...VALID THRU 23/00Z.  ISOLD -TSRA/-SHRA WILL CONTINUE IN
THE WHITE MOUNTAINS AND SOUTH/SOUTHEAST OF KTUS IN THE VICINITY OF
THE KOLS/KDUG TERMINALS THRU 22/04Z WITH BRIEF WIND GUSTS TO NEAR 35
KTS POSSIBLE.  OTHERWISE...SCT TO LOCALLY BKN 8K FT SCT-BKN 14K FT
EAST OF KTUS WITH CLEAR SKIES WEST OF KTUS.  BREEZY SURFACE WIND IN
THE GILA RIVER VALLEY WITH WLY/NWLY SURFACE WIND AT 12-17 KTS AND
GUSTS TO 25 MPH THRU 22/03Z.  OTHERWISE SFC WIND GENERALLY 12 KTS OR
LESS.  AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...THERE WILL BE A SLIGHT CHANCE OF THUNDERSTORMS THIS
EVENING AND TUESDAY NEAR THE INTERNATIONAL BORDER FROM NOGALES TO
DOUGLAS AND IN THE EASTERN MOUNTAINS ALONG THE NEW MEXICO BORDER.
STRENGTHENING HIGH PRESSURE ALOFT WILL RESULT IN HOTTER TEMPERATURES
TUESDAY THROUGH THURSDAY.  WITH THE HOT TEMPS...INCREASED
THUNDERSTORM ACTIVITY SHOULD OCCUR STARTING ON WEDNESDAY AND
CONTINUE INTO NEXT WEEKEND.

&&

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

&&

$$

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