Flash Flood Warning 143, NWS Las Vegas, NV

891 
WGUS75 KVEF 202138
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
238 PM PDT TUE AUG 20 2013

NVC023-202146-
/O.CAN.KVEF.FF.W.0143.000000T0000Z-130820T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NYE NV-
238 PM PDT TUE AUG 20 2013

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR CENTRAL NYE
COUNTY...

THERE HAS BEEN NO RAIN OVER THE WARNING AREA FOR A WHILE. ANY 
FLOODING WHICH MAY HAVE OCCURRED WILL HAVE SUBSIDED. 

LAT...LON 3799 11611 3798 11591 3771 11590 3771 11610

$$

JH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
935 AM PDT TUE AUG 20 2013

.SYNOPSIS...ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED ACROSS
MUCH OF THE AREA TODAY BEFORE DRYING BEGINS TO TAKE PLACE FROM THE
WEST ON WEDNESDAY. THIS WILL RESULT IN THUNDERSTORMS BEING CONFINED
TO MAINLY MOHAVE COUNTY THURSDAY AND FRIDAY. HOWEVER...THUNDERSTORMS
ARE EXPECTED TO MOVE BACK INTO SOUTHERN NEVADA AND SOUTHEAST
CALIFORNIA LATE IN THE WEEKEND. TEMPERATURES WILL BE NEAR NORMAL
THROUGH THE PERIOD.
&&

.UPDATE...SATELLITE LOOP SHOWED DEBRIS CLOUDS MOVING NORTH AND
THINNING OUT AS EXPECTED. PLENTY OF MOISTURE REMAINS IN PLACE AND
UPPER LEVEL FLOW IS BROADLY DIFLUENT...SO SHOULD BE ANOTHER ACTIVE
AFTERNOON. GRIDS LOOK REPRESENTATIVE AND NO UPDATE PLANNED AT THIS
TIME.
&&

.PREV DISCUSSION...
325 AM PDT TUE AUG 20 2013

.SHORT TERM...TODAY THROUGH WEDNESDAY...RADAR AND SATELLITE LOOPS
SHOW PARTLY TO MOSTLY CLOUDY SKIES ACROSS MUCH OF THE REGION THIS
MORNING. MUCH OF THIS WILL THIN AND MOVE NORTH OF THE AREA THIS
MORNING...AND SHOULD ALLOW FOR ENOUGH DAYTIME HEATING AND
DESTABILIZATION TO CREATE ISOLATED TO SCATTERED THUNDERSTORMS THIS
AFTERNOON. THE 00Z AND 06Z NAM RUNS BOTH CAME IN A BIT WETTER OVER
WESTERN SAN BERNARDINO COUNTY TODAY THAN THE ECMWF/GFS RUNS. SINCE
THE NAM SEEMS TO BE INITIALIZED FAIRLY WELL I WENT AHEAD AND BUMPED
UP POPS OVER THE HIGHER TERRAIN AND FAVORED AREAS THERE.
OTHERWISE...THE BEST CHANCES FOR ACTIVITY TODAY WILL BE NORTH OF LAS
VEGAS WITH AT LEAST A SLIGHT CHANCE PRETTY MUCH CWA-WIDE. HIGH-RES
MODELS INDICATE THAT MUCH OF THE ACTIVITY WILL REMAIN ANCHORED TO
THE TERRAIN TODAY...HOWEVER STORMS THAT DO MOVE OFF THE TERRAIN
SHOULD MOVE NORTHEAST AT 10-15 MPH. WITH A BIT MORE SHEAR
TODAY...THERE MAY BE SOME MORE HAIL WITH STRONGER STORMS...OTHERWISE
FLASH FLOODING AND GUSTY WINDS WILL BE THE MAIN THREATS.

FOR WEDNESDAY...MUCH MORE SIGNIFICANT DRYING WILL TAKE PLACE FROM
THE WEST...LIMITING MOST OF THE CONVECTION TO MOHAVE...LINCOLN...AND
THE HIGHER ELEVATIONS OF CLARK COUNTY. THOUGH I DID LEAVE JUST A
SLIGHT CHANCE OVER THE SIERRA DURING THE AFTERNOON. TEMPERATURES
WILL BE AROUND NORMAL TODAY...AND CLIMB A DEGREE OR TWO WEDNESDAY.

.LONG TERM...THURSDAY THROUGH MONDAY...THE UPPER LOW LIFTING ACROSS
NORTHERN CALIFORNIA THURSDAY WILL KEEP A DRY SOUTHWEST FLOW IN PLACE
THROUGH FRIDAY OVER MOST OF THE AREA EXCEPT MOHAVE COUNTY WHERE
ISOLATED THUNDERSTORMS WILL STILL BE POSSIBLE. FOCUS WILL THEN TURN
TOWARD THE TROPICS OFF THE WEST COAST OF CENTRAL MEXICO WHERE MEDIUM
RANGE MODELS HAVE BEEN INDICATING A TROPICAL SYSTEM DEVELOPING THEN
MOVING UP ALONG THE BAJA PENINSULA SATURDAY AND SUNDAY. A LOOK AT
RECENT SATELLITE LOOPS REVEALS THAT WAS NO SIGN OF A TROPICAL SYSTEM
SPINNING UP YET. SO...IT IS TOO EARLY TO GET OVERLY EXCITED ABOUT
IT. ALSO...THERE ARE CONSIDERABLE DIFFERENCES IN THE TRACK OF THE
SYSTEM AFTER SUNDAY...ESPECIALLY BETWEEN THE OPERATIONAL GFS AND
ECMWF. THE SYSTEM CIRCULATION IS FORECAST TO BE NEAR THE BAJA SPUR
SUNDAY MORNING BY BOTH SOLUTIONS. THE 00Z GFS THEN LIFTS THE BODY OF
THE TROPIC SYSTEM AND ALL ASSOCIATED MOISTURE UP ACROSS NORTHERN
BAJA AND INTO SOUTHERN NEVADA BY MONDAY. THAT WOULD BE A RARE AND
WIDESPREAD PRECIP EVENT. THE 00Z ECMWF...BY CONTRAST...TURNS THE
SYSTEM TO THE WEST AND DISSIPATES IT OVER THE COLDER PACIFIC WATERS.
THE MAIN STORY WILL BE THE POTENTIAL THAT THIS SCENARIO WILL HAVE AT
INDUCING A DEEP GULF SURGE UP INTO SOUTHERN NEVADA AND SURROUNDING
AREAS LATE SATURDAY AND SUNDAY. CONFIDENCE IN THIS SURGE IS
INCREASING SLIGHTLY WITH EACH MODEL RUN AND POPS/DEWPOINTS/CLOUD
COVER WERE NUDGED UPWARD ACCORDINGLY ALONG WITH A DECREASE IN HIGH
TEMPERATURES SUNDAY AND MONDAY. THIS HAS THE POTENTIAL TO BE THE
MOST SIGNIFICANT INFLUX OF MOISTURE INTO THE REGION THIS SUMMER. NOW
WE JUST NEED THAT TROPICAL SYSTEM TO DEVELOP FIRST.

.AVIATION...FOR MCCARRAN...THUNDERSTORMS ARE EXPECTED TO FORM AROUND
THE KLAS VALLEY AROUND NOON TODAY...AND MAY IMPACT THE VALLEY AFTER
21Z. OUTSIDE OF STORMS...WINDS SHOULD GENERALLY BE SOUTH AROUND 5-10
KTS. SCT-BKN CLOUDS AROUND 10-12K FEET...BUT MAY LOWER TO AROUND 8K
FEET NEAR STORMS.

FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...THUNDERSTORM COVERAGE IS EXPECTED TO BE A BIT MORE
WIDESPREAD TODAY...MAINLY OVER THE HIGHER TERRAIN ACROSS THE AREA.
GUSTY AND ERRATIC WINDS POSSIBLE WITH ANY STORMS. OUTSIDE OF ANY
STORMS...WINDS SHOULD GENERALLY BE SOUTHEAST TO SOUTH AROUND 10 KTS.
SCT-BKN CLOUDS AROUND 10-12K FEET...BUT WILL LOWER TO AROUND 8K FEET
NEAR STORMS.
&&

.VEF WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
AZ...NONE.
CA...NONE.
&&

MORGAN/WOLCOTT/ADAIR

FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:

HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LAS VEGAS NV
436 AM PDT TUE AUG 20 2013

AZZ001>003-036-CAZ519>527-NVZ014>022-210700-
NORTHWEST PLATEAU-LOWER COLORADO RIVER VALLEY-NORTHWEST DESERTS-
LAKE MEAD NATIONAL RECREATION AREA-EASTERN SIERRA SLOPES-
OWENS VALLEY-WHITE MOUNTAINS OF INYO COUNTY-
DEATH VALLEY NATIONAL PARK-WESTERN MOJAVE DESERT-
EASTERN MOJAVE DESERT-MORONGO BASIN-CADIZ BASIN-
SAN BERNARDINO COUNTY-UPPER COLORADO RIVER VALLEY-
ESMERALDA AND CENTRAL NYE COUNTY-LINCOLN COUNTY-
NORTHEAST CLARK COUNTY-WESTERN CLARK AND SOUTHERN NYE COUNTY-
SHEEP RANGE-SPRING MOUNTAINS-LAS VEGAS VALLEY-
SOUTHERN CLARK COUNTY-
436 AM PDT TUE AUG 20 2013 /436 AM MST TUE AUG 20 2013/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHWEST
ARIZONA...SOUTHEAST CALIFORNIA AND SOUTHERN NEVADA.

.DAY ONE...TODAY AND TONIGHT

ISOLATED TO SCATTERED THUNDERSTORMS CAN BE EXPECTED THROUGH THIS
EVENING...ESPECIALLY NEAR HIGHER TERRAIN. STORM MOVEMENT WILL BE TO
THE NORTHEAST AT 10 TO 15 MPH. THE PRIMARY HAZARD WITH ANY STORM
WILL BE HEAVY RAIN AND THE POTENTIAL FOR FLASH FLOODING. STRONG
GUSTY WINDS AND HAIL WILL ALSO BE POSSIBLE WITH A FEW STORMS.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

DRYING IS EXPECTED TO TAKE PLACE FROM SOUTHWEST TO NORTHEAST
TONIGHT AND WEDNESDAY THEN ISOLATED STORMS SHOULD BE CONFINED TO
NORTHWEST ARIZONA THURSDAY AND FRIDAY. A TROPICAL SYSTEM NEAR BAJA
CALIFORNIA MAY INFLUENCE THE WEATHER THIS WEEKEND INTO EARLY NEXT
WEEK. THERE IS SOME POTENTIAL FOR A SURGE OF MOISTURE FROM THE GULF
OF CALIFORNIA INTO THE MOJAVE DESERT LATE SATURDAY INTO SUNDAY WHICH
WOULD LEAD TO EXTENSIVE THUNDERSTORM COVERAGE. CONFIDENCE IS STILL
LOW IN THE DETAILS OF THIS SCENARIO BUT CHANCES OF THUNDERSTORMS
WILL TREND UPWARD SUNDAY AND MONDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. HOWEVER...
SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

JA