FNUS75 KSLC 200027
FWSSLC

SPOT FORECAST FOR TWITCHELL CANYON
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
627 PM MDT THU AUG 19 2010

.DISCUSSION...THE STRONG DISTURBANCE THAT MOVED ACROSS NORTHERN
UTAH EARLIER TODAY HAS BROUGHT DRY AIR IN BEHIND IT ACROSS THE
NORTHERN TWO THIRDS OF THE REGION. MOISTURE WILL REMAIN OVER
SOUTHERN UTAH THROUGH FRIDAY AND SOME MAY BE BROUGHT NORTHWARD FOR
A SLIGHT CHANCE OF THUNDERSTORMS...MAINLY MOUNTAINS BY FRIDAY
AFTERNOON AS A WEAK UPPER LEVEL DISTURBANCE MOVES NORTHEAST. A
BROAD TROUGH WILL SET UP ALONG THE WEST COAST BY SATURDAY ALLOWING
SOME MOISTURE TO SEEP FARTHER NORTH AS WELL AS BRING STRONGER
SOUTHWEST WINDS BACK ACROSS THE FIRE BOTH SATURDAY AND SUNDAY. A
FIRE WEATHER WATCH HAS BEEN ISSUED FOR SATURDAY FOR THE ADJACENT
ZONE TO YOUR WEST FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY. BY
SUNDAY ENOUGH MOISTURE IS EXPECTED TO COME BACK NORTH TO HAVE
HIGHER RELATIVE HUMIDITY PREEMPT THE NEED FOR A WATCH.

THE TROUGH AXIS WILL MOVE ACROSS THE AREA ON SUNDAY AND THE
ASSOCIATED COLD FRONT WILL MOVE ACROSS THE FIRE SUNDAY NIGHT
SHIFTING THE WINDS TO THE NORTH. DRY NORTHERLY FLOW IS EXPECTED
MONDAY INTO EARLY TUESDAY...BUT THUNDERSTORMS COULD BE BACK IN THE
PICTURE BY TUESDAY AFTERNOON.

.TONIGHT...
LAL...................1.
HAINES INDEX..........3 ..VERY LOW.
SKY/WEATHER...........CLEAR (0-10 PERCENT CLOUD COVER).
MIN TEMPERATURE.......50-54 AT 8000 FT AND 39-43 AT 10000 FT.
MAX HUMIDITY..........85 TO 93 PERCENT AT 8000 TO 10000 FT.
WIND (20 FT)..........SOUTHWEST WINDS 5 MPH SHIFTING TO THE NORTH LATE
                      IN THE EVENING.

.FRIDAY...
LAL...................1.
  CWR.................0.
HAINES INDEX..........5 ..MODERATE.
CLEARING INDEX........1000+.
SKY/WEATHER...........MOSTLY SUNNY (15-25 PERCENT CLOUD COVER).
MAX TEMPERATURE.......79-82 AT 8000 FT AND 70-74 AT 10000 FT.
MIN HUMIDITY..........24-28 PERCENT AT 8000 FT AND 32-36% AT 10000 FT.
WIND (20 FT)..........UPSLOPE AT 8000 FT AT 5 MPH AND SOUTHWEST WINDS
                      5 TO 10 MPH AT RIDGETOP.

.OUTLOOK FOR SATURDAY...
LAL...................1 EARLY AND 2 AFTER 1500.
  CWR.................0.
HAINES INDEX..........5 ..MODERATE.
CLEARING INDEX........1000+.
SKY/WEATHER...........MOSTLY SUNNY (10-20 PERCENT CLOUD COVER) THEN
                      BECOMING PARTLY CLOUDY (40-50 PERCENT CLOUD
                      COVER). SLIGHT CHANCE OF A THUNDERSTORM.
MAX TEMPERATURE.......82-84 AT 8000 FT AND 72-76 AT 10000 FT.
MIN HUMIDITY..........19-23 PERCENT AT 8000 FT AND 27-32% AT 10000 FT.
WIND (20 FT)..........SOUTH SOUTHWEST WINDS 10 TO 15 MPH AFTER 1100 MDT
                      INCREASING TO 15-20 MPH AFTER 1400 MDT. GUSTS ON
                      RIDGES COULD EXCEED 30 MPH.

.OUTLOOK FOR SUNDAY...
LAL...................1 BECOMING 2 AFTER 1400.
  CWR.................5 PERCENT.
HAINES INDEX..........5 ..MODERATE
CLEARING INDEX........1000+.
SKY/WEATHER...........PARTLY CLOUDY (40-50 PERCENT CLOUD
                      COVER). CHANCE OF THUNDERSTORMS.
MAX TEMPERATURE.......78-82 AT 8000 FT AND 68-72 AT 10000 FT.
MIN HUMIDITY..........25-30 PERCENT AT 8000 FT AND 34-39% AT 10000 FT.
WIND (20 FT)..........SOUTHWEST WINDS 10 TO 15 MPH AFTER 1100 MDT
                      INCREASING TO 15-20 MPH AFTER 1400 MDT. GUSTS ON
                      RIDGES COULD EXCEED 30 MPH.
.OUTLOOK FOR MONDAY...
LAL...................1.
  CWR.................0.
HAINES INDEX..........4 ..LOW.
CLEARING INDEX........1000+.
SKY/WEATHER...........MOSTLY SUNNY (0-20 PERCENT CLOUD COVER).
MAX TEMPERATURE.......76-80 AT 8000 FT AND 66-70 AT 10000 FT.
MIN HUMIDITY..........20-24 PERCENT AT 8000 FT AND 28-33% AT 10000 FT.
WIND (20 FT)..........NORTH TO NORTHEAST WINDS AT 5-10 MPH.

FORECASTER...STRUTHWOLF
REQUESTED BY...GSORENSON
REASON FOR REQUEST...WILDFIRE
.TAG 20100819.TWITC.02/SLC

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