FNUS75 KSLC 081458
FWSSLC

SPOT FORECAST FOR CLEAR TRAP
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
858 AM MDT TUE MAY 8 2012

.DISCUSSION...WEAK UPPER LEVEL CIRCULATION THAT PASSED OVERHEAD
YESTERDAY HAS SETTLED INTO NORTHERN ARIZONA THIS MORNING. AS A
RESULT AIRMASS OVERHEAD REMAIN QUITE UNSTABLE WITH GOOD
VENTILATION POTENTIAL. WINDS ARE RATHER LIGHT AND WILL BE
DOMINATED BY DIURNAL FLUCTUATIONS...BUT WITH THIS AIRMASS EXPECT
SOME AFTERNOON GUSTS INTO THE LOW TO MID TEENS THIS AFTERNOON.
THE AREA WILL REMAIN CLEAR AND DRY THIS MORNING...BUT DO EXPECT A
FEW AFTERNOON BUILDUPS OVER THE TERRAIN TO THE NORTH OF THE CLEAR
TRAP SITE OWING TO A SLIGHT CHANCE FOR A BRIEF SHOWER OR ISOLATED
LIGHTNING STRIKE IN THE VICINITY. IF THIS MOVES OVER THE SITE
THIS AFTERNOON...AFTER 14/1500...LOOK FOR BRIEF ERRATIC WINDS BUT
PRECIP SHOULD BE NEGLIGIBLE. THE UPPER LEVEL CIRCULATION WILL
TRANSITION EAST TONIGHT AND TOMORROW ALLOWING RIDGING AND A MUCH
MORE STABLE AIRMASS TO MOVE IN FROM THE NORTH...INCREASED
STABILITY EXPECTED TO LOWER CLEARING INDICES INTO THE POOR
CATEGORY.

OUTLOOK FOR THE REMAINDER OF THE WEEK...SOUTHWESTERLY FLOW ALOFT
WILL INCREASE THURSDAY AS A COLD FRONT MOVES INTO NORTHERN UTAH.
THIS FRONT WILL STALL OVER CENTRAL UTAH THURSDAY NIGHT INTO
FRIDAY ALLOWING GOOD TO EXCELLENT MIXING POTENTIAL FROM THURSDAY
ON...WARM TEMPS AND DRY CONDITIONS EXPECTED.

.TODAY...
  LAL.................1 UNTIL NOON...THEN 2.
  HAINES INDEX........4 ..LOW.
  CLEARING INDEX......1000+.
  SKY/WEATHER.........PARTLY CLOUDY (45-55 PERCENT CLOUD COVER). A
                      SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS
                      AFTER NOON.
  MAX TEMPERATURE.....71-73.
  MIN HUMIDITY........15-19 PERCENT.
  WINDS - 20-FOOT.....DOWNSLOPE/DOWNVALLEY 3 TO 7 MPH THROUGH 1200
                      THEN NORTHEAST TO NORTH WINDS 5 TO 8 MPH WITH
                      A FEW GUSTS TO 15 MPH IN THE AFTERNOON.

.TONIGHT...
  LAL.................1.
  HAINES INDEX........4 ..LOW.
  SKY/WEATHER.........PARTLY CLOUDY (40-50 PERCENT CLOUD COVER).
  MIN TEMPERATURE.....37-39.
  MAX HUMIDITY........68-70 PERCENT.
  WINDS - 20-FOOT.....DECREASING NORTHERLY WINDS BECOMING
                      DOWNSLOPE/DOWNVALLEY 4 TO 7 MPH BY 2200.

.OUTLOOK FOR WEDNESDAY...
  LAL.................1.
  HAINES INDEX........4 ..LOW.
  CLEARING INDEX......360.
  SKY/WEATHER.........MOSTLY SUNNY (10-20 PERCENT CLOUD COVER) THEN
                      BECOMING PARTLY CLOUDY (25-35 PERCENT CLOUD
                      COVER).
  MAX TEMPERATURE.....77-79.
  MIN HUMIDITY........14-16 PERCENT.
  WINDS - 20-FOOT.....NORTH WINDS 10 MPH SHIFTING TO THE SOUTHEAST
                      IN THE AFTERNOON.



FORECASTER...MERRILL
REQUESTED BY...JAMES COURTRIGHT
REASON FOR REQUEST...PRESCRIBED
.TAG 20120508.CLEAR.01/SLC

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