Severe Thunderstorm Warning 51, NWS Tucson, AZ

000 
WWUS55 KTWC 282113
SVSTWC

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TUCSON AZ
208 PM MST SAT JUL 28 2007

AZC019-282118-
/O.CAN.KTWC.SV.W.0051.000000T0000Z-070728T2130Z/
PIMA AZ-
208 PM MST SAT JUL 28 2007

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN PIMA COUNTY IS 
CANCELLED...
...FLASH FLOOD WARNING REMAINS IN EFFECT FOR EASTERN PIMA COUNTY 
UNTIL 245 PM MST...

SOME THUNDERSTORMS REMAINED STRONG ACROSS PORTIONS OF EASTERN PIMA 
COUNTY...BUT ALL HAD REDUCED IN INTENSITY TO BELOW SEVERE LEVELS. 
EXPECT HEAVY RAINFALL TO CONTINUE WITH SOME OF THESE STORMS. A FLASH 
FLOOD WARNING REMAINS IN EFFECT UNTIL 245 PM MST.

LAT...LON 3236 11093 3230 11113 3196 11092 3223 11058

$$

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE TUCSON AZ
1132 AM MST SAT JUL 28 2007

.SYNOPSIS...HIGH PRESSURE CENTERED OVER NEVADA...COMBINED WITH
AN UPPER LEVEL LOW OVER THE SOUTHERN PLAINS...WILL RESULT IN A
PARTICULARLY ACTIVE MONSOON PATTERN THROUGH AT LEAST MONDAY. THE
UPPER LEVEL LOW WILL EVENTUALLY MOVE ACROSS NORTHERN MEXICO BY
TUESDAY. ONCE THIS HAPPENS...THERE SHOULD BE A SLIGHT DECREASE IN
THUNDERSTORM ACTIVITY.

&&

.UPDATE...HAVE UPDATED FORECAST TO ISSUE FLASH FLOOD WATCH. AS SOON
AS WE REACHED THE MID 80S...TSTMS BEGAN TO BLOSSOM AND TRAIN N-S.
HAVE ALREADY HAD SEVERAL SPOTTER REPORTS OF 1 INCH/30 MIN RATES IN
THE INITIAL SMALL CELLS. SATELLITE TRENDS SHOW SOME SORT OF WEAK MID
LEVEL CONVERGENCE BANDS SETTING UP FROM THE E RIM AND GILA COUNTY
THROUGH THE HEART OF THE CWA WHICH WILL LIKELY SUPPORT CLUSTERING
INTO AN MCS OVER THE NEW FEW HOURS. HAVE KEPT FAR W PIMA OUT FOR NOW
SINCE ANY TSTMS ON THE W RIM WOULD HAVE TO TRAVEL SEVERAL HOURS TO
REACH THERE...AND THE APPARENT CONVERGENCE AXIS IS FOR THE MOMENT
WELL TO THE E. WILL CONTINUE TO MONITOR THAT AREA IN CASE WE NEED TO
EXPAND LATER.

&&

.AVIATION...EXPECT DEBRIS CLOUDINESS THROUGH EARLY AFTERNOON WITH
ISOLATED THUNDERSTORMS ACROSS PARTS OF SOUTHEAST ARIZONA NEAR KOLS
AND KDUG THRU 19Z OR SO. DAYTIME HEATING...COMBINED WITH THE UPPER
LOW OVER TEXAS MOVING CLOSER TO THE STATE...WILL RESULT IN FAIRLY
WIDESPREAD THUNDERSTORM REDEVELOPMENT THIS AFTERNOON AND TONIGHT.
LIKE WE HAVE SEEN ALL WEEK...THE VERY MOIST ATMOSPHERE WILL SUPPORT
BRIEF IFR VISIBILITIES AND WIND GUSTS AOA 40KTS. AVIATION DISCUSSION
NOT UPDATED FOR TAF AND TWEB AMENDMENTS.

&&

.PREV DISCUSSION...IN A BIT OF A QUANDARY ON A POSSIBLE FLASH FLOOD
WATCH AT THE MOMENT. SCATTERED TSTMS IN SANTA CRUZ AND
COCHISE...ALONG WITH PLENTY OF DEBRIS CLOUDS...ARE SLOWING OUR
HEATING QUITE A BIT THIS MORNING. 12Z UPPER AIR DATA...WHILE SHOWING
VERY MOIST AND UNSTABLE SOUNDINGS AT TWC...PSR AND FGZ...ALSO
SUGGEST THE BEST DIFFLUENCE AND WEAKEST INERTIAL STABILITY ALOFT
RESIDES NW OF US OVER THE WESTERN RIM. BOTH THE NAM12 AND GFS ALSO
SUGGEST WE MAY SEE A BIT OF SUBSIDENCE/WARMING ALOFT DURING THE
AFTERNOON AS OUR FLOW TRIES TO TURN FROM NNW TO NNE. STILL THE
ATMOSPHERE CURRENTLY OVERHEAD IS OBVIOUSLY PRIMED...AND OUR 85F
CONVECTIVE TEMP WOULD THEORETICALLY YIELD A CAPE CLOSE TO 2000 J/KG.
THE CELLS WE HAVE HAD THIS MORNING HAVE BEEN PRETTY EFFICIENT RAIN
PRODUCERS. SINCE WERE GOING TO UPDATE GRIDS/ZONES TO ACCOUNT FOR
ONGOING CONVECTION AND CLOUD COVER...WELL ALSO ADD HEAVY RAIN
WORDING FOR THIS AFTERNOON/ TONIGHT AND AWAIT FURTHER DEVELOPMENTS.
THE OTHER CONCERN IS THAT IS IF WE DO ORGANIZE OFF THE RIM...WE
COULD END UP WITH A FLASH FLOOD THREAT WELL INTO THE NIGHT IF THE
NAM12 IS RIGHT AND THE BETTER SUPPORT ALOFT SHIFTS INTO S AZ. OUR
CURRENT POPS ARE INDICATING THIS POTENTIAL ALREADY. SEEING HOW
THINGS DEVELOP THROUGH THIS AFTERNOON SHOULD HELP PINPOINT
IF...WHERE...AND HOW LONG WE MAY NEED TO RUN A WATCH.

REST OF THE FORECAST IS IN GOOD SHAPE...WITH TEMPS RUNNING BELOW
NORMAL IN OUR VERY MOIST ATMOSPHERE...AND POPS SET AT 10-15 PCT
ABOVE CLIMO UNTIL THE UPPER LOW SHEARS TO OUR S EARLY IN THE NEW
WEEK.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...FLASH FLOOD WATCH UNTIL 9 PM MST
ZONES 19/29/30/32/33/34/35.

&&

PYTLAK

WEATHER.GOV/TUCSON

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
412 AM MST SAT JUL 28 2007

AZZ019-029>035-282200-
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-
412 AM MST SAT JUL 28 2007

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

.DAY ONE...TODAY AND TONIGHT

A WEAK DISTURBANCE ROTATING AROUND THE NORTHERN PERIPHERY OF A
LOWER PRESSURE SYSTEM SPINNING OVER TEXAS WILL ENTER THE AREA
TODAY. THIS FEATURE COMBINED WITH DAYTIME HEATING WILL LEAD TO
WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY. DUE TO A VERY MOIST
AIR MASS IN PLACE AND WEAK STEERING WINDS ALOFT...HEAVY DOWNPOURS
CAN BE EXPECTED. SOME OF THE STRONGER THUNDERSTORMS MAY PRODUCE
STRAIGHT LINE WINDS IN EXCESS OF 58 MPH AS WELL. PERSON ACROSS
SOUTHEAST ARIZONA SHOULD REMAIN ALERT TODAY FOR POSSIBLE FLASH
FLOOD WATCHES...ADVISORIES...OR WARNINGS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

SCATTERED MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS
CAN BE EXPECTED THROUGH THE PERIOD. SOME OF THE STORMS MAY PRODUCE
HEAVY DOWNPOURS WITH RUNOFF PROBLEMS.

.SPOTTER INFORMATION STATEMENT...

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

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TUCSON AZ
1206 PM MST SAT JUL 28 2007

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1205 PM     FLASH FLOOD      SIERRA VISTA            31.55N 110.29W
07/28/2007                   COCHISE            AZ   LAW ENFORCEMENT

            SEVERAL STREETS FLOODED ON WEST SIDE OF SIERRA
            VISTA...INCLUDING FRY BLVD. AND 7TH AVE.

&&

PYTLAK