Dust Devil in Nevada, April 29, 2015

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
1021 AM PDT WED APR 29 2015

.SYNOPSIS...SEVERAL UPPER LEVEL WAVES WILL TRAVERSE ACROSS THE GREAT
BASIN THROUGH THE END OF THE WEEK. ENOUGH MOISTURE AND INSTABILITY
WILL BE AVAILABLE FOR ISOLATED AFTERNOON SHOWERS AND THUNDERSTORMS
TO DEVELOP OVER THE HIGHER ELEVATIONS OF THE SOUTHERN GREAT BASIN
FROM THURSDAY THROUGH EARLY NEXT WEEK. WELL ABOVE NORMAL
TEMPERATURES WILL CONTINUE...WITH THE WARMEST HIGHS OF THE YEAR SO
FAR EXPECTED ON THURSDAY AND FRIDAY.
&&

.UPDATE...CIRRUS CLOUDS ARE DRIFTING NORTHEAST ACROSS THE AREA THIS
MORNING AHEAD OF AN INCOMING MID/UPPER LEVEL TROUGH. THESE SHOULD
SPREAD EAST THROUGH THE DAY BUT IT SHOULD NOT BE ENOUGH TO HAMPER A
MOSTLY SUNNY FORECAST. THE CURRENT GRIDS LOOK IN GREAT SHAPE AND NO
CHANGES ARE NEEDED.
&&

.AVIATION...FOR MCCARRAN...WINDS ARE EXPECTED TO BECOME EASTERLY
THIS MORNING BEFORE TRANSITIONING TO A SOUTH-SOUTHWEST DIRECTION
DURING THE AFTERNOON AND INCREASING TO 10-14 KTS WITH GUSTS OF 16-20
KTS. THERE COULD BE SOUTHEASTERLY WINDS AT 8-12 KTS SHORTLY BEFORE
THE SOUTH-SOUTHWEST WINDS KICK IN. WINDS SHOULD REMAIN SOUTH-
SOUTHWEST THIS EVENING BUT DECREASE SLIGHTLY TO 7-10 KTS. A FEW
CLOUDS AOA 25K FEET.

FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...WINDS SHOULD INCREASE FROM THE SOUTH TO SOUTHWEST THIS
AFTERNOON TO 8-14 KTS WITH GUSTS OF 16-22 KTS THEN DECREASE EARLY
THIS EVENING. OVERNIGHT EXPECT TYPICAL DIURNAL DIRECTIONAL TRENDS AT
6-12 KTS. FEW-SCT CLOUDS AOA 25K FEET.
&&

.PREVIOUS DISCUSSION...
ISSUED AT 325 AM PDT WED APR 29 2015

.SHORT TERM...TODAY THROUGH FRIDAY NIGHT.

MOSTLY CLEAR SKIES WILL CONTINUE THROUGHOUT THIS MORNING BEFORE
GIVING WAY TO INCREASING HIGH CLOUDS LATER TODAY AS AN APPROACHING
MID/UPPER LEVEL TROUGH BEGINS TO FLATTEN THE THE RIDGE CURRENTLY IN
PLACE. SUFFICIENT MOISTURE AND INSTABILITY WILL EXIST MAINLY OVER
THE HIGHER ELEVATIONS OF THE SOUTHERN GREAT BASIN TO ALLOW FOR THE
CHANCE FOR ISOLATED AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS
MAINLY ON THURSDAY AND FRIDAY. OTHERWISE...AN INCREASE IN CUMULUS
CLOUDS ARE EXPECTED IN THESE AREAS DURING THE AFTERNOON HOURS WITH
DAYTIME HEATING. SOUTHWESTERLY WINDS WILL INCREASE BY THIS AFTERNOON
WITH A FEW GUSTS POSSIBLE...PROMOTING EXCELLENT MIXING THIS
AFTERNOON AS A RESULT. WITH PLENTY OF WARM AIR ALOFT LEFT
OVER...HIGH TEMPERATURES WILL RISE TO ROUGHLY 10 DEGREES ABOVE
NORMAL TODAY...AND 10-13 DEGREES ABOVE NORMAL THURSDAY AND FRIDAY.

.LONG TERM...SATURDAY MORNING THROUGH WEDNESDAY.

OPERATIONAL MODEL GUIDANCE CONTINUES TO BREAK OFF UPPER LEVEL ENERGY
FROM THE AFOREMENTIONED TROUGH ACROSS THE EASTERN PACIFIC BY
SATURDAY MORNING...INTRODUCING SPLIT FLOW TO THE CWA THROUGH MUCH OF
THE WEEKEND. THIS ENERGY WILL GET WRAPPED UP IN A DISTURBANCE IN THE
SOUTHERN BRANCH OF THE JET SUNDAY AND WILL APPROACH THE AREA BY THE
EARLY PART OF NEXT WEEK. THIS IS WHERE OPERATIONAL MODELS DIVERGE
WITH RESPECT TO STRENGTH/AMPLITUDE...THEREFORE NO MAJOR CHANGES WERE
MADE TO THE INHERITED GRIDS. THE BOTTOM LINE IS THAT UNSETTLED
WEATHER WILL AGAIN BE A POSSIBILITY ACROSS THE CWA THE MID-NEXT WEEK
WITH THE PASSAGE OF THIS SYSTEM AND A POTENTIAL LARGER MID/UPPPER
LEVEL LOW DIGGING INTO THE AREA FROM THE NORTHWEST BY WEDNESDAY.

OTHERWISE...EXPECT ABOVE NORMAL TEMPERATURES TO CONTINUE THROUGH
MUCH OF THE PERIOD WITH A SLIGHT COOL DOWN BEGINNING ON MONDAY AS
THE NEXT SHORTWAVE APPROACHES THE AREA.
&&

.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION IS NOT EXPECTED
TODAY. ISOLATED THUNDERSTORMS ARE POSSIBLE FRIDAY THROUGH MONDAY IN
THE AFTERNOON AND EVENING HOURS AND SPOTTER REPORTS OF ANY
SIGNIFICANT WEATHER THEN ARE APPRECIATED.
&&

UPDATE/AVIATION...STACHELSKI
PREVIOUS...PULLIN

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