Flooding in Utah, July 1 to 15, 2011

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
950 PM MDT THU JUN 30 2011

.SYNOPSIS...HIGH PRESSURE WILL BUILD INTO THE AREA TONIGHT AND
WILL REMAIN IN PLACE THROUGH THE HOLIDAY WEEKEND. MOISTURE WILL
BEGIN TO STREAM NORTHWARD ACROSS SOUTHERN UTAH EARLY NEXT WEEK.

&&

.DISCUSSION...MOSTLY CLEAR SKIES EXIST ACROSS THE FORECAST AREA
THIS EVENING...AS THE TROUGH THAT MOVED THROUGH THE AREA LAST
NIGHT AND THIS MORNING IS FINALLY EXITING THE REGION...BUT NOT
BEFORE SETTING OFF SOME SEVERE CONVECTION ACROSS EASTERN UTAH THIS
MORNING. THE MORE ISOLATED AND WEAKER CONVECTION THAT WAS OBSERVED
IN THE UINTA MOUNTAINS AND UINTA COUNTY WYOMING THIS AFTERNOON AND
EVENING IS SLOWLY MOVING OUT OF THE AREA...AND SHOULD BE
COMPLETELY EAST OF THE CWA BY 06Z.

HIGH PRESSURE WILL SLOWLY BUILD THROUGH TOMORROW...BEFORE BECOMING
STRONGER AND MORE AMPLIFIED SATURDAY AND SUNDAY...LEADING TO A
SIGNIFICANT WARMING TREND FOR THE HOLIDAY WEEKEND. BOTH THE GFS
AND ECMWF INDICATE THAT ADDITIONAL MOISTURE WILL MOVE INTO UTAH
FROM THE SOUTH FOR THE BEGINNING OF NEXT WEEK...LIKELY LEADING TO
AFTERNOON THUNDERSTORMS ACROSS MUCH OF THE CWA HEADING INTO THE
WORK WEEK.

THE CURRENT FORECAST FOR TONIGHT LOOKS TO BE ON TRACK AND NO
UPDATES ARE PLANNED FOR THIS EVENING.

&&

.HYDROLOGY...SEVERAL FLOOD WARNINGS REMAIN IN EFFECT INCLUDING THE
LOGAN RIVER...SPRING CREEK...THE SOUTH SLOPES OF THE UINTAS AND
THE UPPER WEBER RIVER. IN ADDITION...A WARNING WAS ISSUED EARLIER
THIS SHIFT FOR LITTLE COTTONWOOD CREEK...WHICH ONCE AGAIN HAS SEEN
QUICK RISES DURING THE EVENING HOURS. LITTLE COTTONWOOD IS
EXPECTED TO PEAK AROUND MIDNIGHT...GIVE OR TAKE A COUPLE
HOURS...BEFORE GOING DOWN THROUGH THE MORNING.

THE REMAINDER OF RIVERS ACROSS NORTHERN UTAH WILL CONTINUE TO
EXPERIENCE HIGH FLOWS BUT ARE EXPECTED TO REMAIN BELOW FLOOD
LEVELS. EXTREME CAUTION IS URGED NEAR ANY OF THESE RIVERS AS THEY
ARE FLOWING VERY FAST AND VERY COLD.

&&

.AVIATION...LIGHT AND VARIABLE WINDS AT THE SLC TERMINAL AS OF
0330Z ARE EXPECTED TO BECOME STEADY SOUTHEASTERLY BETWEEN 04Z AND
06Z. OTHERWISE...VFR CONDITIONS WILL PREVAIL UNDER MOSTLY CLEAR
SKIES.

&&

.FIRE WEATHER...A STORM SYSTEM WILL EXIT EAST OUT OF THE FIRE
DISTRICT THIS EVENING AND ANY LINGERING SHOWERS WILL QUICKLY
DISSIPATE. HOWEVER...GUSTY WEST TO NORTHWEST WINDS WILL CONTINUE
ACROSS PORTIONS OF EASTERN UTAH IN THE WAKE OF THE SYSTEM BEFORE
WEAKENING THIS EVENING. HAZARDOUS FIRE WEATHER CONDITIONS WILL
CONTINUE TO OCCUR ACROSS PORTIONS OF SOUTHEAST UTAH WHERE FUELS ARE
DRY. A COOLER AND STABLE AIRMASS WILL SETTLE INTO THE AREA TONIGHT.
HIGH PRESSURE WILL THEN SLOWLY BUILD OVER THE NEXT COUPLE OF DAYS
WITH A WARMING TREND THROUGH THE END OF THE WEEK. THE AIRMASS WILL
REMAIN DRY UNTIL THE BEGINNING OF NEXT WEEK WHEN MOISTURE IS
EXPECTED TO SPREAD INTO THE AREA FROM THE SOUTH. EXPECT THUNDERSTORM
COVERAGE TO INCREASE THROUGH THE MIDDLE OF NEXT WEEK.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...NONE.
WY...NONE.
&&

SCHOENING/CHENG

FOR MORE INFORMATION FROM NOAA/S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY (ALL LOWER CASE)

FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
330 PM MDT THU JUN 30 2011

UTZ001>016-019>021-517-518-WYZ021-302330-
CACHE VALLEY/UTAH PORTION-NORTHERN WASATCH FRONT-
SALT LAKE AND TOOELE VALLEYS-SOUTHERN WASATCH FRONT-
GREAT SALT LAKE DESERT AND MOUNTAINS-WASATCH MOUNTAIN VALLEYS-
WASATCH MOUNTAINS I-80 NORTH-WASATCH MOUNTAINS SOUTH OF I-80-
WESTERN UINTA MOUNTAINS-WASATCH PLATEAU/BOOK CLIFFS-
WESTERN UINTA BASIN-CASTLE COUNTRY-SAN RAFAEL SWELL-
SANPETE/SEVIER VALLEYS-WEST CENTRAL UTAH-SOUTHWEST UTAH-
UTAHS DIXIE AND ZION NATIONAL PARK-SOUTH CENTRAL UTAH-
GLEN CANYON RECREATION AREA/LAKE POWELL-CENTRAL MOUNTAINS-
SOUTHERN MOUNTAINS-SOUTHWEST WYOMING-
330 PM MDT THU JUN 30 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE WESTERN TWO THIRDS OF
UTAH AND SOUTHWEST WYOMING.

.DAY ONE...TODAY AND TONIGHT

RIVERS ACROSS THE NORTHERN AND CENTRAL OUTLOOK AREA WILL CONTINUE TO
FLOW AT ELEVATED LEVELS. SEVERAL OF THESE RIVERS REMAIN NEAR OR
ABOVE FLOOD STAGE. TEMPERATURES REMAIN WARM ENOUGH TO CONTINUE TO
MELT THE HIGH ELEVATION SNOWPACK AT ACCELERATED RATES.

IT IS IMPORTANT TO NOTE THAT FLOWS THROUGH MANY WATERWAYS REMAIN
COLD...SWIFT AND POWERFUL...EVEN THOSE THAT ARE BELOW FLOOD
STAGE. THIS COMBINATION IS DANGEROUS NOT JUST FOR CHILDREN...BUT
ADULTS AS WELL. HYPOTHERMIA CAN QUICKLY SET IN WHEN EXPOSED TO
WATER OF THESE TEMPERATURES...SIGNIFICANTLY LIMITING YOUR ABILITY
TO RESCUE YOURSELF.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

SEVERAL RIVERS ACROSS NORTHERN UTAH WILL REMAIN AT OR REACH FLOOD
STAGE OVER THE NEXT FEW DAYS. CONTINUE TO MONITOR FUTURE FLOOD
STATEMENTS FOR ADDITIONAL INFORMATION ON AFFECTED RIVERS. THESE
WATERS ARE DANGEROUSLY COLD AND SWIFT AND ANYONE VENTURING NEAR
THEM SHOULD EXERCISE EXTREME CAUTION.

HIGH PRESSURE WILL STRENGTHEN ACROSS THE REGION DURING THE
UPCOMING HOLIDAY WEEKEND...AND REMAIN IN PLACE THROUGH THE MIDDLE
OF NEXT WEEK. THIS WILL PUSH TEMPERATURES 5 TO 10 DEGREES ABOVE
NORMAL ACROSS THE OUTLOOK AREA.

MOISTURE IS EXPECTED TO SLOWLY INCREASE ACROSS THE OUTLOOK AREA
EARLY NEXT WEEK. THIS WILL ALLOW FOR A FEW THUNDERSTORMS ACROSS
THE HIGHER TERRAIN AS EARLY AS MONDAY AFTERNOON...WITH THE CHANCE
OF AFTERNOON AND EVENING THUNDERSTORMS INCREASING OVER BOTH THE
MOUNTAINS AND VALLEYS BY MIDWEEK.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

FOR MORE INFORMATION FROM NOAA/S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY (ALL LOWER CASE)