Alert archive / Arizona / Special Weather Statements in 2012

Special Weather Statement, NWS Phoenix, AZ

August 15, 2012

NWS Phoenix, AZ issued this special weather statement at Aug 15, 2012, 12:39 AM MST. It was in force for 51 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 15, 2012, 12:39 AM MST (07:39 UTC)
Expired
Aug 15, 2012, 1:30 AM MST
In force
51 min
Issued by
NWS Phoenix, AZ

The radar

The Phoenix radar (KIWA), 84 km from the middle of the area, began a volume at 07:40 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Tuscon, AZ (KDMA), launched 00:00Z, 7.7 hours before the alert went out and 146 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Tuscon, AZ at 00:00Z on 2012-08-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 193 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Tuscon, AZ at 00:00Z on 2012-08-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -35 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
193 J/kg
Mixed-layer CIN
-9 J/kg
Mixed-layer LCL
3692 m above ground
0-6 km bulk shear
5 kt
0-1 km storm-relative helicity
-35 m²/s²
0-3 km storm-relative helicity
12 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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What forecasters said that day

The local office's own words before this special weather statement went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Phoenix, AZ wrote its last area forecast discussion before this special weather statement went out at Aug 14, 11:08 PM MST, 1 hour 31 minutes earlier.

Area forecast discussion, Aug 14, 11:08 PM MST, 1 hour 31 minutes before
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
1108 PM MST TUE AUG 14 2012

.SYNOPSIS...
STRONG HIGH PRESSURE WILL CONTINUE OVER THE DESERT SOUTHWEST THROUGH
WEDNESDAY...RESULTING IN WELL ABOVE NORMAL TEMPERATURES AND PERIODS
OF EXCESSIVE HEAT. MONSOON MOISTURE WILL SLOWLY SPREAD BACK INTO THE
REGION STARTING WEDNESDAY EVENING...RESULTING IN A GRADUAL THREAT OF
AFTERNOON THUNDERSTORM ACTIVITY...MAINLY OVER SOUTHWEST AND SOUTH
CENTRAL ARIZONA THURSDAY THROUGH EARLY NEXT WEEK.

&&

.DISCUSSION...
QUICK UPDATE TO CANCEL THE EXCESSIVE HEAT WARNING FOR WEDNESDAY.
GUSTY OUTFLOW WINDS HAVE ALREADY KNOCKED THE PHOENIX METRO BELOW
CRITERIA. WITH CLOUD COVER EXPECTED TO LINGER THROUGH A PORTION OF
TOMORROW LIMITING SOLAR INSOLATION...IT SEEMS UNLIKELY THAT THE AREA
WILL SEE EXCESSIVE HEAT WARNING CRITERIA REALIZED TOMORROW. FORECAST
REMAINS UNCHANGED OTHERWISE.

&&

.PREVIOUS DISCUSSION...
IR SATELLITE IMAGERY REVEALS A HUGE MCS OVER SONORA MEXICO THIS
EVENING. BOTH THE NAM12/GFS 925-850MB STREAMLINES SUGGEST MORE OF A
SOUTHERLY FLOW THROUGH THE GULF OF CALIFORNIA AND INTO THE SOUTHWEST
DESERTS OF ARIZONA...AND THIS WILL SERVE TO IMPORT MORE MOISTURE
INTO THE REGION...GRADUALLY SHIFTING THE MONSOON MOISTURE BOUNDARY
NORTH AND WEST WITH TIME/THROUGH THURSDAY. THE INFLUX OF MOISTURE
WILL HELP TO MODERATE THE VERY HOT AFTERNOON TEMPS/HEAT WAVE THAT
HAS PERSISTED FOR THE LAST 9 DAYS...MODEL FORECAST SOUNDINGS AND
GUIDANCE ALL POINT TO ABOUT 3-4 DEGREES OF COOLING CWA-WIDE WITH
TEMPS RANGING FROM 107-110 DEGREES FOR WEDNESDAY. EVEN THOUGH THE
TWC 00Z SOUNDING SHOWS PRECIPITABLE WATER IS JUST OVER ONE INCH...
THE TREND OVER THE LAST 12-18 HOURS HAS BEEN A FEW DEGREES OF
COOLING IN THE LOW-MID LEVELS OF THE ATMOSPHERE...AND SOME
INCREASING MID-LEVEL MOISTURE. TAKING ALL THIS INTO CONSIDERATION...
THE EXCESSIVE HEAT WARNING MIGHT NOT BE NEEDED FOR WEDNESDAY...BUT
WILL LEAVE THIS FOR THE ONCOMING SHIFT TO MAKE A DETERMINATION.

AS WITH YESTERDAY EVENING...THERE WAS LITTLE STORM ACTIVITY ACROSS
SOUTHEAST CALIFORNIA AND THE LOWER COLORADO RIVER VALLEY. SO...THE
FOCUS IS ONCE AGAIN OVER SOUTH-CENTRAL ARIZONA. THE CONVECTIVE
POTENTIAL FOR THE REST OF THE EVENING WILL BE DICTATED BY WEAK
BOUNDARY INTERACTION FROM ISOLATED THUNDERSTORMS THAT CONTINUE TO
RING THE CENTRAL DESERTS OF MARICOPA COUNTY/GREATER PHOENIX AREA.
THESE BOUNDARIES WILL MOVE INTO THE PHOENIX METROPOLITAN AREA OVER
THE NEXT SEVERAL HOURS/UNTIL AROUND MIDNIGHT...AND THIS WILL CREATE
SOME GUSTY WINDS/BLOWING DUST...ALONG WITH ISOLATED SHOWERS AND
THUNDERSTORMS BEHIND THE MOVING/COLLIDING BOUNDARIES.

ADJUSTMENTS WERE MADE TO THE POP/WX GRIDS FOR THE SHORT TERM. OTHER
THAN THE POSSIBILITY OF NOT CONTINUING THE EXCESSIVE HEAT WARNING
WEDNESDAY AND ADJUSTING THE FORECAST MAX TEMPERATURES...THE FORECAST
APPEARS TO BE IN GOOD SHAPE.

PREVIOUS DISCUSSION...
WEDNESDAY...ATMOSPHERIC THICKNESS AND LOWER ATMOSPHERIC TEMPERATURES
JUST BARELY SUPPORT ANOTHER EXCESSIVE HEAT DAY WEDNESDAY FOR
SOUTHWEST AND SOUTH CENTRAL AZ. THEREFORE THE EXCESSIVE HEAT WARNING
WILL CONTINUE THROUGH WEDNESDAY EVENING. A SLIGHT CHANCE OF SHOWERS
AND THUNDERSTORMS WILL ALSO CONTINUE OVER PARTS OF SOUTHWEST AND
SOUTH CENTRAL AZ...WITH THE BEST CHANCE IN MOUNTAINOUS SOUTHERN GILA
COUNTY.

THURSDAY THROUGH MONDAY...
WE EXPECT A SIGNIFICANT MOISTURE INCREASE OVER THE AREA...WITH AN
INCREASED THREAT FOR AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS
MAINLY OVER SOUTH CENTRAL ARIZONA...INCLUDING PHOENIX. STRONG UPPER
LEVEL RIDGE BUILDING AND ANTI-CYCLONIC WINDS ALOFT IN SOUTHERN CA
WILL PROBABLY KILL ANY THUNDERSTORM POTENTIAL THIS PERIOD...WITH
ONLY SINGLE DIGIT POPS IN THE AREA.

&&

 .AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA...AND KSDL...THROUGH
ISOLATED THUNDERSTORMS EXPECTED ACROSS THE GREATER PHOENIX AREA FOR
THE NEXT SEVERAL HOURS UNTIL AROUND 09Z. THIS COULD FORCE GUSTY
OUTFLOW WINDS TO 30KTS FOR A SHORT TIME...AND VISIBILITY AT
KIWA/KPHX COULD POSSIBLY DROP DOWN TO 2-3 SM IN BLOWING DUST.
OTHERWISE...VARIABLE WINDS GENERALLY 10KT OR LESS FROM 09Z THROUGH
19Z WED WITH SCT-BKN CLOUDS AOA 12KFT.

SOUTHEAST CA AND SOUTHWEST AZ...INCLUDING KIPL AND KBLH...
FROM 06Z THROUGH 19Z WED...SCT CLOUD DECKS AOA 15KFT WITH LIGHT
WINDS UNDER 10 KNOTS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
INCREASED MONSOON MOISTURE WILL BRING CONTINUED CHANCES OF AFTERNOON
AND EVENING SHOWERS AND THUNDERSTORMS EACH DAY...MAINLY OVER SOUTH
CENTRAL ARIZONA AREAS. MINIMUM RELATIVE HUMIDITIES WILL GENERALLY BE
IN THE TWENTIES ACROSS THE LOWER DESERT AND CLOSER TO 40 PERCENT
ACROSS SOUTHERN GILA COUNTY MOUNTAINS. TEMPERATURES ARE EXPECTED TO
BE NEAR NORMAL THROUGH THE PERIOD.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...LEINS/MEYERS/VASQUEZ
AVIATION...MEYERS
FIRE WEATHER...KUHLMAN
Hazardous weather outlook, Aug 14, 11:21 PM MST, 1 hour 18 minutes before
HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
1121 PM MST TUE AUG 14 2012

AZZ024-151400-
SOUTHERN GILA COUNTY/TONTO NATIONAL FOREST FOOTHILLS-
1121 PM MST TUE AUG 14 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST-CENTRAL ARIZONA.

.DAY ONE...TONIGHT.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

THERE WILL BE A CHANCE OF MAINLY AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS THROUGHOUT THE FIVE DAY PERIOD. THE PRIMARY WEATHER
HAZARDS INCLUDE GUSTY WINDS IN EXCESS OF 40 MPH...LOCALLY HEAVY RAIN
WITH LOCALIZED FLOODING OF STREAMS...WASHES AND ROADS...AND DEADLY
CLOUD TO GROUND LIGHTNING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

AZZ023-027-028-151400-
GREATER PHOENIX AREA-SOUTHWEST MARICOPA COUNTY-
NORTHWEST AND NORTH CENTRAL PINAL COUNTY-
1121 PM MST TUE AUG 14 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH-CENTRAL ARIZONA.

.DAY ONE...TONIGHT.

SCATTERED SHOWERS AND THUNDERSTORMS WILL LINGER THROUGH THE EARLY
MORNING HOURS. LOCALLY GUSTY WINDS ARE POSSIBLE AS WELL AS BRIEF
PERIODS OF HEAVY RAIN AND LOCALIZED FLOODING.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

MONSOON MOISTURE IS EXPECTED TO INCREASE FROM THE SOUTH LATER
WEDNESDAY AND IT WILL LEAD TO BOTH COOLER HIGH TEMPERATURES AND A
CHANCE OF MAINLY AFTERNOON AND EVENING THUNDERSTORMS BEGINNING
THURSDAY AND CONTINUING THROUGH THE WEEKEND. THE PRIMARY WEATHER
HAZARDS ASSOCIATED WITH THE THUNDERSTORMS INCLUDE GUSTY WINDS IN
EXCESS OF 45 MPH...DENSE BLOWING DUST ALONG WITH SHARPLY REDUCED
VISIBILITY...LOCALLY HEAVY RAIN AND DEADLY LIGHTNING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

AZZ022-151400-
NORTHWEST MARICOPA COUNTY-
1121 PM MST TUE AUG 14 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH-CENTRAL ARIZONA.

.DAY ONE...TONIGHT.

SCATTERED SHOWERS AND THUNDERSTORMS WILL LINGER THROUGH THE EARLY
MORNING HOURS. LOCALLY GUSTY WINDS ARE POSSIBLE AS WELL AS BRIEF
PERIODS OF HEAVY RAIN AND LOCALIZED FLOODING.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

MONSOON MOISTURE IS EXPECTED TO INCREASE FROM THE SOUTH LATER
WEDNESDAY AND IT WILL LEAD TO BOTH COOLER HIGH TEMPERATURES AND A
CHANCE OF MAINLY AFTERNOON AND EVENING THUNDERSTORMS BEGINNING
THURSDAY AND CONTINUING THROUGH THE WEEKEND. THE PRIMARY WEATHER
HAZARDS ASSOCIATED WITH THE THUNDERSTORMS INCLUDE GUSTY WINDS IN
EXCESS OF 45 MPH...DENSE BLOWING DUST ALONG WITH SHARPLY REDUCED
VISIBILITY...LOCALLY HEAVY RAIN AND DEADLY LIGHTNING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

AZZ020-021-025-026-CAZ031>033-151400-
LOWER COLORADO RIVER VALLEY AZ-WEST CENTRAL DESERTS-
YUMA/MARTINEZ LAKE AND VICINITY-SOUTHWEST DESERTS-
LOWER COLORADO RIVER VALLEY CA-RIVERSIDE COUNTY/EASTERN DESERTS-
IMPERIAL COUNTY-
1121 PM MST TUE AUG 14 2012 /1121 PM PDT TUE AUG 14 2012/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EXTREME SOUTHWEST
ARIZONA...EXTREME WEST-CENTRAL ARIZONA...SOUTHWEST ARIZONA...WEST-
CENTRAL ARIZONA AND EXTREME SOUTHEAST CALIFORNIA.

.DAY ONE...TONIGHT.

NO WEATHER HAZARDS ARE EXPECTED.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

INCREASING MONSOON MOISTURE FROM THE SOUTH WILL LEAD TO BOTH COOLER
TEMPERATURES AND AN INCREASING CHANCE OF AFTERNOON AND EVENING
THUNDERSTORMS STARTING ON THURSDAY. THE BEST CHANCE OF THUNDERSTORMS
WILL BE OVER THE SOUTHWEST ARIZONA DESERTS FROM THURSDAY THROUGH
SATURDAY. THE PRIMARY WEATHER HAZARDS ASSOCIATED WITH THE
THUNDERSTORMS INCLUDE GUSTY WINDS IN EXCESS OF 45 MPH...DENSE BLOWING
DUST AND SAND WITH SHARPLY REDUCED VISIBILITY...LOCALLY HEAVY RAIN
AND DEADLY LIGHTNING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

CAZ030-151400-
JOSHUA TREE NATIONAL PARK-
1121 PM PDT TUE AUG 14 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST CALIFORNIA.

.DAY ONE...TONIGHT.

NO WEATHER HAZARDS ARE EXPECTED.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

THERE WILL BE AN INCREASE IN MONSOON MOISTURE...AND THIS WILL LEAD
TO A SLIGHT CHANCE FOR MAINLY AFTERNOON AND EVENING THUNDERSTORMS
FROM THURSDAY THROUGH THE WEEKEND. THE PRIMARY WEATHER HAZARDS WITH
ANY THUNDERSTORMS THAT DEVELOP INCLUDE GUSTY WINDS IN EXCESS OF 40
MPH... PATCHY BLOWING DUST OR SAND AT LOWER PARK ELEVATIONS...BRIEF
HEAVY RAINFALL AND DEADLY LIGHTNING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT

WEATHER.GOV/PHOENIX

In the hours before

Special weather statement, Aug 14, 10:32 PM MST, 2 hours 7 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PHOENIX AZ
1032 PM MST TUE AUG 14 2012

AZZ023-150615-
MARICOPA AZ-
1032 PM MST TUE AUG 14 2012

...SIGNIFICANT WEATHER ADVISORY...

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

SIGNIFICANT WEATHER ADVISORY FOR...
  CENTRAL MARICOPA COUNTY IN SOUTH CENTRAL ARIZONA

UNTIL 1115 PM MST

AT 1029 PM MST...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
STRONG THUNDERSTORM NEAR PHOENIX...MOVING NORTHEAST AT 5 MPH.

WIND GUSTS UP TO 50 MPH ARE EXPECTED WITH THIS STORM...ALONG WITH
FREQUENT DANGEROUS LIGHTNING.

LOCATIONS IMPACTED INCLUDE...
   PIESTEWA PEAK PARK...
   CAMELBACK MOUNTAIN...
   PARADISE VALLEY...

LAT...LON 3366 11199 3351 11187 3344 11210 3355 11217
TIME...MOT...LOC 0532Z 242DEG 6KT 3354 11204

MO
Special weather statement, Aug 15, 12:00 AM MST, 39 minutes before
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Special weather statement, Aug 15, 12:39 AM MST, 0 minutes before
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The office that day

Everything else NWS Phoenix, AZ issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 14, 9:41 PM MSTBlowing Dust AdvisoryPSR79 min
Aug 14, 10:32 PM MSTSpecial Weather StatementPSRMaricopa43 min
Aug 14, 10:37 PM MSTAreal Flood AdvisoryPSRMaricopa, Pinal113 min
Aug 14, 10:53 PM MSTAreal Flood AdvisoryPSRMaricopa112 min
Aug 14, 11:16 PM MSTBlowing Dust AdvisoryPSR104 min
Aug 14, 11:28 PM MSTAreal Flood AdvisoryPSRPinal2 hr
Aug 15, 12:00 AM MSTSpecial Weather StatementPSRMaricopa45 min
Aug 15, 12:18 AM MSTAreal Flood AdvisoryPSRMaricopa, Pinal117 min
Aug 15, 2:46 PM MSTSpecial Weather StatementPSR44 min
Aug 15, 3:22 PM MSTAreal Flood AdvisoryPSRGila3 hr
Aug 15, 3:24 PM MSTSpecial Weather StatementPSRGila51 min
Aug 15, 4:30 PM MSTSpecial Weather StatementPSRGila30 min
Aug 14, 5:02 PM MSTBlowing Dust AdvisoryPSR58 min
Aug 14, 5:15 PM MSTSpecial Weather StatementPSRImperial45 min

Nearby

Special Weather Statements in Arizona, 2012Every special weather statement in 2012

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.