Severe Thunderstorm Warning 19, NWS Tucson, AZ

000 
WWUS55 KTWC 150145
SVSTWC

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TUCSON AZ
645 PM MST TUE JUL 14 2009

AZC023-150200-
/O.CON.KTWC.SV.W.0019.000000T0000Z-090715T0200Z/
SANTA CRUZ AZ-
645 PM MST TUE JUL 14 2009

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM MST
FOR SOUTH CENTRAL SANTA CRUZ COUNTY...

AT 643 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN
EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR NOGALES...MOVING WEST 
AT 5 MPH.

LAT...LON 3134 11102 3147 11099 3148 11085 3134 11080
TIME...MOT...LOC 0145Z 075DEG 6KT 3138 11092

$$

000 
WWUS55 KTWC 150202
SVSTWC

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TUCSON AZ
702 PM MST TUE JUL 14 2009

AZC023-150211-
/O.EXP.KTWC.SV.W.0019.000000T0000Z-090715T0200Z/
SANTA CRUZ AZ-
702 PM MST TUE JUL 14 2009

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL SANTA CRUZ
COUNTY HAS EXPIRED...

THE THUNDERSTORM IN THE VICINITY OF THE CITY OF NOGALES THAT 
PROMPTED THE SEVERE THUNDERSTORM WARNING HAD WEAKENED BELOW SEVERE 
LEVELS. THUS...THE SEVERE THUNDERSTORM WARNING HAS BEEN ALLOWED TO 
EXPIRE.

LAT...LON 3134 11102 3147 11099 3148 11085 3134 11080
TIME...MOT...LOC 0145Z 075DEG 6KT 3138 11092

$$

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
228 PM MST TUE JUL 14 2009

.SYNOPSIS...HIGH PRESSURE ALOFT OVER NEW MEXICO WILL REMAIN IN PLACE
THROUGH FRIDAY AS AN UPPER LEVEL LOW OVER THE SOUTHERN BAJA
PENINSULA LIFTS NORTH TOWARD SOUTHERN CALIFORNIA. SOUTHEAST FLOW
DEVELOPING BETWEEN THESE TWO SYSTEMS WILL DRAW DEEPER MONSOON
MOISTURE NORTH AND LEAD TO A BETTER CHANCE OF MAINLY AFTERNOON AND
EVENING THUNDERSTORMS. ONCE THE DISTURBANCE LIFTS INTO THE GREAT
BASIN THIS WEEKEND...THE HIGH WILL MOVE INTO ARIZONA...LEADING TO
LESS THUNDERSTORMS AND A RETURN TO NEAR RECORD HEAT.

&&

.DISCUSSION...TSTMS WERE DEVELOPING AS EXPECTED NEAR THE MOISTURE
BOUNDARY BETWEEN 1.5+ INCH PRECIPITABLE WATER ALONG AND SOUTH OF THE
BORDER...AND MUCH DRIER AIR TO THE NORTH. OUR MAIN CONCERN WILL BE
FOR TSTMS THROWING OFF A MICROBURST OR TWO DUE TO OUR INVERTED-V
SOUNDINGS...OR IF A FEW TSTMS CAN CLUSTER AND PUSH LARGER OUTFLOWS
NORTH. LATER TONIGHT...UNCERTAINTY INCREASES AS TSTMS OVER MEXICO
CONSOLIDATE INTO EITHER A COUPLE OF MESOSCALE CONVECTIVE SYSTEMS OR
A FULL SCALE MESOSCALE CONVECTIVE COMPLEX...WITH THEIR DEEP OUTFLOWS
PUSHING INTO SOUTHERN AZ LATE TONIGHT. HAVE PURPOSELY KEPT LOW POPS
PAST MIDNIGHT CLOSE TO THE BORDER...ALTHOUGH THIS MAY NOT BE FAR
ENOUGH NORTH IF THE COMPLEX IS TOO CLOSE AND/OR OUTFLOWS END UP TOO
MOISTURE-RICH. EVENING SHIFT WILL BE IN A BETTER POSITION TO MONITOR
EXACTLY WHERE THE COMPLEX CONSOLIDATES AND ADJUST POPS UP OR DOWN
ACCORDINGLY.

MODELS ARE JUST STARTING TO GET A CLUE ABOUT THE 700-MILE-WIDE UPPER
LOW OVER SOUTHERN BAJA AND THE POSSIBILITY OF AT LEAST A MODEST GULF
SURGE LATE TONIGHT AS THIS FEATURE MAKES ITS TURN NNW. GFS SEEMS TO
HAVE A BETTER HANDLE ON IT...BUT EVEN THAT MODEL IT IS STILL TOO
WEAK AND NOT LARGE ENOUGH. GFS BUFR SOUNDINGS ARE INTERESTING IT
THAT THEY DO INDEED SHOW A SURGE MAKING IT INTO SOUTHERN AZ...WITH
SOMEWHAT HIGHER PRECIP WATER...BETTER LEVEL MOISTURE... DECENT SE
STEERING FLOW AND RESPECTABLE 850-500MB BULK SHEAR. BUT THEY ALSO
SHOW A COOLER BOUNDARY LAYER CAPPED BY A WARM/DRY RESIDUAL BOUNDARY
LAYER AT 800-750MB. THAT PROBABLY EXPLAINS WHY THE GFS IS CALLING
FOR A 6-10 DEGREE TEMP DROP...NO SURFACE-BASED CAPE...AND ONLY
ISOLATED TSTM COVERAGE. NAM12 IS BONE DRY. THEN THERE IS THE
UNCERTAINTY ABOUT WHAT ROLE LEFTOVER MESOSCALE CONVECTIVE VORTICES
MAY PLAY TOMORROW...NOT TO MENTION THE FACT THAT THE UPPER HIGH IS
IN SOUTHERN NM AND NOT SOME PLACE MORE FAVORABLE. WITH THIS IN
MIND...WE HAVE NUDGED POPS UP ONLY SLIGHTLY WED/WED NIGHT DESPITE
THE MUCH BETTER UPPER LEVEL ENVIRONMENT...WHILE WE WAIT AND SEE HOW
THE SURGE AND OVERNIGHT TSTMS PLAY OUT. IF WE END UP WITH A STRONGER
AND DEEPER SURGE COUPLED WITH FULL SUN...MUCH HIGHER POPS AND
STRONGER WORDING WOULD BE IN ORDER. HAVE ALSO PLAYED THU
CONSERVATIVELY SINCE CONVECTIVE POTENTIAL WILL DEPEND ON WHAT
HAPPENS TOMORROW. DYNAMICS LOOKS JUST AS GOOD ON THU AS THE UPPER
LOW MOVES INTO S CA AND WE REMAIN ON THE DIVERGENT E FLANK...BUT BY
THEN WE COULD BE WORKED OVER AND IN DEBRIS CLOUDS. ALL THIS IS A
LONG WINDED WAY OF SAYING WE COULD BE PRETTY ACTIVE WED AND/OR
THU...BUT THERE IS STILL A LOT OF DEVIL IN THE DETAILS.

ONCE THE UPPER LOW LIFTS INTO THE GREAT BASIN FRI...THE EAST COAST
TROUGH WILL AMPLIFY AS THE UPPER HIGH RETROGRADES INTO AZ. MODELS
STILL MANAGE TO SUPPORT ISOLATED TSTMS AS WEAK RIPPLES ROTATE AROUND
THE HIGH AND WORK ON RESIDUAL MOISTURE. THAT IS NOT UNCOMMON WHEN
THE UPPER HIGH IS DIRECTLY OVER AZ...BUT UNFORTUNATELY THAT SCENARIO
IS USUALLY ACCOMPANIED BY UNCOMFORTABLY HOT DAYS AND VERY WARM
NIGHTS. 12Z MEX NUMBERS HAVE NUDGED UPWARD WITH 850-700MB
THICKNESSES SUPPORTING NEAR RECORD HIGHS. WILL HOLD JUST SHORT OF
HEAT ADVISORY CRITERIA SINCE THE MODEL HEIGHTS/THICKNESSES WERE A
LITTLE OVERDONE LAST WEEKEND...AND THE ECMWF ALONG WITH A MINORITY
OF ENSEMBLE MEMBERS ARE STILL HINTING AT A MORE 4 CORNER/N AZ RIDGE
PLACEMENT.

&&

.AVIATION...ISOLATED TSTMS HAVE DEVELOPED AS EXPECTED THIS AFTERNOON
AND WILL CONTINUE INTO EARLY EVENING. BEST CHANCE OF BRIEF MVFR
+TSRA AND GUSTS TO 40KTS IS AT KOLS...WITH GUSTY OUTFLOWS/VCTS
PROBABLY AFFECTING BOTH KTUS AND KDUG LATE THIS AFTERNOON OR
EVENING. OUTSIDE THUNDERSTORMS...EXPECT NORMAL DIURNAL WIND TRENDS
THIS EVENING. WIND FORECAST MORE UNCERTAIN AFTER 06Z SINCE THERE IS
A CHANCE THAT OUTFLOWS FROM TSTMS IN SONORA WILL PUSH N OF THE
BORDER AFTER 06Z. IF THAT OCCURS...WINDS COULD BECOME GUSTY FOR A
COUPLE OF HOURS FROM THE S OR SE. AVIATION DISCUSSION NOT UPDATED
FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...A MOISTURE INCREASE IS EXPECTED TONIGHT AND WED
WHICH WILL BRING A BETTER CHANCE OF THUNDERSTORMS AND WETTING RAINS
WEDNESDAY THROUGH FRIDAY. OUTSIDE OF THUNDERSTORM OUTFLOWS...WINDS
WILL NOT BE A CONCERN AS THEY WILL REMAIN DIURNAL IN NATURE.

&&

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

PYTLAK

WEATHER.GOV/TUCSON

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
945 AM MST TUE JUL 14 2009

AZZ019-029>035-150700-
NORTHERN GREENLEE COUNTY-SOUTHEAST PINAL COUNTY-
UPPER GILA RIVER VALLEY-WESTERN PIMA COUNTY-TOHONO OODHAM NATION-
TUCSON METRO/MARANA/GREEN VALLEY-SANTA CRUZ COUNTY-COCHISE COUNTY-
945 AM MST TUE JUL 14 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTH CENTRAL
ARIZONA AND SOUTHEAST ARIZONA.

.DAY ONE...TODAY AND TONIGHT

THE MAIN WEATHER HAZARD TODAY INVOLVES OUR CONTINUING HEAT.
TEMPERATURES WILL ONCE AGAIN APPROACH RECORD HIGHS...WITH SOME OF
THE DESERTS WEST OF TUCSON REACHING 110 DEGREES. THE GREATEST RISK
OF THUNDERSTORMS THIS AFTERNOON WILL ONCE AGAIN WILL BE ALONG THE
INTERNATIONAL BORDER BETWEEN BISBEE AND SASABE. A COUPLE OF THESE
STORMS COULD BE RATHER STRONG...AND MAY PRODUCE WIND GUSTS
APPROACHING SEVERE LIMITS. ALSO LIKE YESTERDAY...A FEW OUTFLOWS
FROM THESE BORDER THUNDERSTORMS COULD RADIATE NORTH LATE THIS
AFTERNOON AND EARLY THIS EVENING ACROSS SOUTHEAST ARIZONA. THESE
OUTFLOWS COULD BRING BRIEFLY GUSTY WINDS OF 40 TO 50 MPH AND
LOCALIZED BLOWING DUST. THEY COULD ALSO IGNITE A COUPLE OF VALLEY
STORMS...BUT THE RISK OF WIDESPREAD SEVERE WEATHER IS LOW...AND
MOST THUNDERSTORMS ARE EXPECTED TO DISSIPATE BY MIDNIGHT.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

AN UPTICK IN THUNDERSTORM ACTIVITY IS EXPECTED BEGINNING ON
WEDNESDAY AND CONTINUING INTO THE WEEKEND. THIS INCREASE COULD
ALSO INCREASE THE RISK OF BOTH SEVERE THUNDERSTORMS AND HEAVY
RAIN...BUT THOSE DETAILS ARE STILL UNCERTAIN. DESPITE THIS
INCREASE IN THUNDERSTORMS...IT WILL REMAIN HOT ACROSS SOUTHEAST
ARIZONA THROUGH EARLY NEXT WEEK WITH ABOVE AVERAGE TEMPERATURES.

.SPOTTER INFORMATION STATEMENT...

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

PYTLAK

WEATHER.GOV/TUCSON