FNUS75 KSLC 041537
FWSSLC

SPOT FORECAST FOR TWITCHELL CANYON
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
937 AM MDT WED AUG 4 2010

.DISCUSSION...DEEP MOISTURE REMAINS IN PLACE ACROSS THE REGION
AND WILL ONLY GRADUALLY TREND TO DRY OVER THE NEXT 36-48 HOURS.
CLEAR SKIES THIS MORNING ARE PROMOTING RAPID TEMP RISES LOCALLY
AT TWITCHELL...BUT ANTICIPATE BUILDING CLOUD COVER MIDDAY WILL
ALLOW DAILY MAX TEMPS TO OCCUR BY EARLY THIS AFTERNOON. THREAT
-FOR THUNDERSTORMS WILL INCREASE RAPIDLY AFTER 1400 AS STORMS LOOK
TO BUILD OFF OF NEIGHBORING TUSHAR MTNS...ESPECIALLY DUE TO SUCH
A RAPID INCREASE OF MORNING TEMPS THIS AM PROMOTING
DESTABILIZATION. THREAT FOR ERRATIC AND GUSTY WINDS...HEAVY RAIN
AND FREQUENT LIGHTNING REMAINS WITH THUNDERSTORMS TODAY. STORM
ACTIVITY WILL WANE SIGNIFICANTLY WITH LOSS OF SOLAR THIS EVENING
ALLOWING LIGHT DRAINAGE FLOWS TO DOMINATE. WIND TRENDS EXPECTED
TO INCREASE SLIGHTLY FROM THE SOUTH ON THURSDAY...WITH THREAT FOR
STORMS IN THE AFTERNOON REMAINING...BUT TAKING A SLIGHT DOWNWARD
TREND IN PROBABILITIES.

LOOKING OUT...PATTERN CHANGE EXPECTED FOR THIS WEEKEND INTO NEXT WEEK.
MUCH DRIER CONDITIONS EXPECTED.

.TODAY...
LAL...................1 UNTIL NOON...THEN 4.
HAINES INDEX..........4 ..LOW.
CLEARING INDEX........940.
SKY/WEATHER...........PARTLY CLOUDY (40-50 PERCENT CLOUD COVER).
                      BUILDUPS FORMING AFTER 1100...SCATTERED STORMS
                      BUILDING OFF THE TUSHAR RANGE AFTER 1200. HIGHEST THREAT
                      FOR THUNDERSTORMS IN THE 1400 TO 2000 TIMEFRAME.
MAX TEMPERATURE.......87-91 BY EARLY AFTERNOON...THEN TRENDING TO COOL.
MIN HUMIDITY..........17-22 PERCENT BY LATE MORNING THEN SLOWLY CLIMBING
WIND (20 FT)..........DOWNSLOPE 3 TO 6 MPH GUST 9 MPH THROUGH 1100 SWITCHING TO
                      UPSLOPE 4 TO 9 MPH GUST 15 MPH FOR THE AFTERNOON.

.TONIGHT...
LAL...................4 UNTIL MIDNIGHT...THEN 2.
HAINES INDEX..........3 ..VERY LOW.
SKY/WEATHER...........PARTLY CLOUDY (35-45 PERCENT CLOUD COVER).
                      SCATTERED SHOWERS AND THUNDERSTORMS UNTIL
                      MIDNIGHT...THEN A SLIGHT CHANCE OF SHOWERS
                      AND THUNDERSTORMS.
MIN TEMPERATURE.......48-54.
MAX HUMIDITY..........60-66 PERCENT.
WIND (20 FT)..........SOUTHWEST WINDS 10 MPH BECOMING DOWNSLOPE/DOWNVALLEY
                      AFTER 2300.

.OUTLOOK FOR THURSDAY...
LAL...................2 UNTIL NOON...THEN 4.
HAINES INDEX..........3 ..VERY LOW.
CLEARING INDEX........1000+.
SKY/WEATHER...........PARTLY CLOUDY (40-50 PERCENT CLOUD COVER). A
                      SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS IN
                      THE MORNING...THEN A CHANCE OF SHOWERS AND
                      THUNDERSTORMS IN THE AFTERNOON.
MAX TEMPERATURE.......85-90.
MIN HUMIDITY..........17-22 PERCENT.
WIND (20 FT)..........DOWNSLOPE/DOWNVALLEY 4 TO 7 MPH BECOMING SOUTH
                      10 TO 15 MPH WITH GUSTS TO 20 MPH
                      LATE IN THE AFTERNOON.



FORECASTER...MERRILL
REQUESTED BY...CLAY MATHESON
REASON FOR REQUEST...WILDFIRE
.TAG 20100804.TWITC.01/SLC

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