FNUS75 KSLC 042254
FWSSLC

SPOT FORECAST FOR TWITCHELL CANYON
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
454 PM MDT SAT SEP 4 2010

...RED FLAG WARNING BELOW 7000 FEET NOON TO 2100 SUNDAY FOR WIND
AND LOW HUMIDITY...

.DISCUSSION...A WARM DRY SOUTHWEST FLOW WILL CONTINUE ACROSS
THE FIRE SITE THROUGH THIS EVENING. THE AFTERNOON WINDS HAVE
DEVELOPED AND SHOULD STAY ABOUT AS THEY ARE THROUGH ABOUT 1900
WITH GUSTS FROM 25 TO 30 MPH...THEN START TO DECOUPLE. THIS WILL
CREATE NEAR CRITICAL WIND AND HUMIDITY CONDITIONS UNTIL WINDS
START TO DIMINISH. IT WILL BE A MILD NIGHT WITH POOR HUMIDITY
RECOVERY THEN WINDS PICK UP AGAIN SUNDAY BY LATE MORNING AND ARE
EXPECTED TO BE STRONGER THAN TODAY. HUMIDITY WILL REMAIN VERY
LOW.

THE VICINITY OF THE FIRE IS UNDER A RED FLAG WARNING FOR
ELEVATIONS BELOW 7000 FEET FROM NOON TO 2100 SUNDAY. THE WIND AND
HUMIDITY CONDITIONS AT THE FIRE WILL BE SIMILAR TO THAT AT THE
LOWER ELEVATIONS AND WILL LIKELY EXCEED CRITICAL LEVELS.

A COLD FRONT WILL CROSS THE FIRE SUNDAY EVENING AROUND 2100 WITH
A SHARP WIND SHIFT TO NORTHERLY. THE WINDS WILL REMAIN STRONG FOR
ABOUT AN HOUR OR SO BEHIND THE FRONT THEN DROP OFF.

MONDAY IS EXPECTED TO COOLER WITH LIGHT NORTHWEST WINDS.

THE OUTLOOK FOR TUESDAY THROUGH THURSDAY...SOUTHWEST WINDS
REDEVELOP TUESDAY AFTERNOON AND INCREASE WEDNESDAY AHEAD OF THE
NEXT PACIFIC STORM. TEMPERATURES WILL WARM UP AGAIN THROUGH
WEDNESDAY. THE COLD FRONT WILL CROSS THE FIRE SITE EARLY THURSDAY
WITH A SLIGHT CHANCE OF A SHOWER OR THUNDERSTORM. WINDS WILL DROP
OFF BEHIND THE FRONT.




.TONIGHT...
  LAL.................1.
  HAINES INDEX........5 ..MODERATE.
  SKY/WEATHER.........MOSTLY CLEAR (0-10 PERCENT CLOUD COVER).
  MIN TEMPERATURE.....55-58.
  MAX HUMIDITY........26-28 PERCENT.
  WINDS - 20-FOOT.....SOUTHWEST WINDS 15 TO 20 MPH WITH GUSTS
                      NEAR 30 MPH UNTIL ABOUT 1900 THEN 5-10 MPH.
                      WINDS MAY NOT SWITCH TO LOCAL DOWNSLOPE
                      TONIGHT.

.SUNDAY...
  LAL.................1.
  HAINES INDEX........6 ..HIGH.
  CLEARING INDEX......1000+.
  SKY/WEATHER.........SUNNY (0-5 PERCENT CLOUD COVER).
  MAX TEMPERATURE.....80.
  MIN HUMIDITY........11-13 PERCENT.
  WINDS - 20-FOOT.....WINDY. SOUTH WINDS 20 MPH INCREASING TO
                      SOUTHWEST 30 MPH WITH GUSTS TO AROUND 45 MPH
                      IN THE AFTERNOON. WINDS SHIFTING TO NORTH
                      AROUND 2100 THEN DIMINISHING AFTER 2200.

.OUTLOOK FOR MONDAY...
  LAL.................1.
  HAINES INDEX........4 ..LOW.
  CLEARING INDEX......150.
  SKY/WEATHER.........MOSTLY SUNNY (5-15 PERCENT CLOUD COVER).
  MAX TEMPERATURE.....66-68.
  MIN HUMIDITY........11-13 PERCENT.
  WINDS - 20-FOOT.....NORTHWEST WINDS 5 MPH.



FORECASTER...WILENSKY
REQUESTED BY...RIFC
REASON FOR REQUEST...WILDFIRE
.TAG 20100904.TWITC.01/SLC

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