Flooding in Utah, March 16 to 17, 2011

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
422 PM MDT WED MAR 16 2011

.SYNOPSIS... A COLD FRONT WILL SURGE NORTH TO SOUTH TONIGHT
REACHING SOUTHERN UTAH THURSDAY MORNING. THE COLD FRONT WILL STALL
OVER SOUTHERN UTAH THURSDAY BEFORE MOVING OUT OF THE AREA THURSDAY
NIGHT.

&&

.DISCUSSION...A STRONG COLD FRONT JUST PASSED THROUGH THE KSLC
TERMINAL OVER THE LAST HOUR...THIS AFTER REMAINING NEARLY
STATIONARY THROUGH THE DAY OVER THE SOUTHERN END OF THE GSL.
TIGHTENING BAROCLINICITY UPSTREAM OF THE FRONT THE FOCUS FOR
VALLEY RAIN AND SNOW (ABOVE 7000FT) ACROSS THE NORTHERN WASATCH
FRONT/MOUNTAINS THIS AFTERNOON. AN AREAL INCREASE OF PRECIP HAS
BEEN NOTED FOR THE LAST FEW HOURS ON KMTX...CONSISTENT WITH
GUIDANCE PRODUCING SIGNIFICANT QPF FOR THE EVENING HOURS
TONIGHT ACROSS NORTHERN UTAH.

SOUTH OF THE FRONT SOUTHERLY WINDS WILL CONTINUE TO RAMP
UP DUE TO TIGHTENING PRESSURE GRADIENT AND INCREASING
SOUTHWESTERLY WINDS ALOFT. PEAK 700MB WINDS ARRIVE THIS EVENING
(40-50KTS ACROSS SOUTHERN UTAH)...BUT STILL CONFIDENT VALLEYS WILL
DECOUPLE BY THE MIDDLE OF THE NIGHT. ADVISORIES IN PLACE ACROSS
MUCH OF CENTRAL/SOUTHERN UTAH LOOK EITHER ON TRACK OR HAVE
ALREADY VERIFIED.

WITH PASSAGE OF THE FRONT SNOW LEVELS WILL LOWER RAPIDLY.
ANTICIPATE INTENSITY OF PRECIP WILL DRAG LEVELS DOWN FASTER THAN
NORMAL...BUT VALLEYS ALONG THE I-15 CORRIDOR WILL LIKELY SEE ONLY 1
TO 3 HOURS OF SNOWFALL LATE TONIGHT AND OR TOMORROW MORNING
KEEPING ACCUMULATIONS AND IMPACT ON THE LOW SIDE. THAT SAID...CAN
NOT RULE OUT PATCHY SLUSH ON AREA ROADWAYS BETWEEN NEPHI AND
FILLMORE IN CENTRAL UTAH...AND THE BENCHES ALONG THE WASATCH FRONT.

HAVE OPTED TO LEAVE WINTER WEATHER HIGHLIGHTS AS IS SINCE LAST
UPDATE. FOR THE MOUNTAINS OF NORTHERN UTAH A SOLID 8 TO 16 INCHES
FORECAST TO FALL IN RAPID FASHION BEFORE TAPERING THURSDAY MORNING.
THE MOUNTAIN VALLEYS AND SOUTHWEST WYOMING REMAIN MARGINAL FOR
SNOW ADVISORY CRITERIA...BUT IMPACT FROM 2 TO 6+ INCHES LOOKS
SIGNIFICANT ON AREA ROADWAYS DURING THE MIDDLE AND LATTER HALF OF
THE NIGHT. THE CENTRAL MOUNTAINS ARE NOT EXPECTED TO SEE THE
BRUNT OF SNOWFALL BUT ARE MAINTAINED WITHIN ADVISORIES DUE TO A
FEW INCHES OF ACCUMULATING SNOW ON ROADWAYS...NAMELY SPANISH FORK
CANYON TO SOLDIERS SUMMIT ON US 6 AND THE HIGHER SUMMITS ON
I-15/70 NEAR SCIPIO AND COVE FORT.

SHORT WAVE RESPONSIBLE FOR PROGRESSING THE FRONT TONIGHT WILL
PULL OFF TO THE EAST THURSDAY MORNING ALLOWING THE FRONT TO STALL
ROUGHLY ON A LINE FROM CEDAR CITY TO GREEN RIVER. PRECIP TO WANE
WITH PARTIAL CLEARING AND INSTABILITY SHOWERS IN THE NORTH...AND
SHOWERS ALONG THE BOUNDARY IN THE SOUTH. UPPED POPS ACROSS THE
SOUTH FOR THURSDAY AFTERNOON/EVENING AS THE YET ANOTHER SHORT WAVE
WILL RACE NORTHEAST ALONG THE BOUNDARY SPARKING INCREASED PRECIP
ACROSS THE SOUTHERN/EASTERN MOUNTAINS AND THE SOUTHEASTERN VALLEYS.

SHORT WAVE RIDGING WILL BUILD FRIDAY INTO SATURDAY AS THE NEXT
EASTERN PACIFIC TROUGH RELOADS ALONG THE CALIFORNIA COASTLINE.
GFS/EC HAVE FAIR AGREEMENT REGARDING INITIAL SHORT WAVES TO EJECT
NORTHEAST THROUGH THE GREAT BASIN LATER SATURDAY AND SUNDAY. UPPED
POPS ACROSS THE FAR NORTH AS THESE LOOK TO ONLY GRAZE NORTHERN
PORTIONS OF THE STATE...MUCH OF THE ENERGY REMAINING IN NV/ID.
THIS SAID...THE WEEKEND AHEAD LOOKS RELATIVELY DRY AND BREEZY
WITH WARMING TEMPS FOR MOST AREAS IN THE CWA.

PROGRESSION OF THE PARENT TROUGH NOW TAKING FORM AS WELL...GLOBAL
MODELS SUGGEST IT WILL OPEN UP AND LIFT NORTHEAST THROUGH THE
REGION MONDAY THROUGH TUESDAY. ANTICIPATE POP TRENDS TO INCREASE
FOR THESE PERIODS OVER THE NEXT SEVERAL SHIFTS.

&&

.AVIATION...COLD FRONT MOVED ACROSS THE SLC TERMINAL NEAR 21Z...AND
ASSOCIATED NORTHWEST WINDS SHOULD CONTINUE THROUGH THE EVENING.
WINDS WILL BE INITIALLY GUSTY...BUT ARE EXPECTED TO WEAKEN WITH THE
ONSET OF PRECIPITATION BETWEEN 22Z AND 00Z. VFR CONDITIONS ARE
EXPECTED TO DETERIORATE TO MVFR WITH HEAVIER PRECIPITATION. THE MOST
LIKELY TIME FOR THIS TO OCCUR IS BETWEEN 00Z AND 05Z. CONDITIONS ARE
EXPECTED TO DETERIORATE INTO THE IFR/LIFR RANGE AS RAIN CHANGES TO
SNOW BETWEEN 05Z AND 07Z...THOUGH THERE IS A 20 PERCENT CHANCE THE
CHANGEOVER WILL OCCUR EARLIER THAN EXPECTED.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...WIND ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR UTZ013>016-019>021.

     WINTER WEATHER ADVISORY UNTIL 4 PM MDT THURSDAY FOR UTZ007>009.

     WINTER WEATHER ADVISORY UNTIL 9 AM MDT THURSDAY FOR UTZ006.

     WINTER WEATHER ADVISORY UNTIL 4 PM MDT THURSDAY FOR UTZ010-517.

     WIND ADVISORY UNTIL 6 AM MDT THURSDAY FOR UTZ518.

WY...WINTER WEATHER ADVISORY UNTIL 9 AM MDT THURSDAY FOR WYZ021.

&&

MERRILL/TRAPHAGAN

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
305 AM MDT WED MAR 16 2011

UTZ001>016-019>021-517-518-WYZ021-171300-
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-
305 AM MDT WED MAR 16 2011

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

.DAY ONE...TODAY AND TONIGHT

A FAIRLY STRONG COLD FRONT WILL CROSS NORTHERN UTAH
THROUGH THIS EVENING...AND CENTRAL AND SOUTHERN UTAH LATER TONIGHT
INTO THURSDAY. THUNDERSTORMS WILL BE POSSIBLE AS THE COLD FRONT
CROSSES THE STATE THIS AFTERNOON AND EVENING. BEHIND THE
FRONT...COLDER AIR WILL FILTER INTO THE REGION...ALLOWING THE SNOW
LEVEL TO FALL TO THE VALLEY FLOOR WITH MINOR ACCUMULATIONS
POSSIBLE. BETTER ACCUMULATIONS CAN BE EXPECTED ACROSS THE COLDER
VALLEYS SUCH AS THE WASATCH MOUNTAIN VALLEYS AND SOUTHWEST
WYOMING. THE ADJACENT MOUNTAINS WILL SEE A MODERATE SNOWFALL
THROUGH TOMORROW. PLEASE REFER TO THE WINTER WEATHER ADVISORY FOR
ADDITIONAL DETAILS.

SOUTHERLY WINDS WILL BECOME QUITE GUSTY ACROSS PORTIONS OF CENTRAL
AND SOUTHERN UTAH THIS AFTERNOON AND EVENING. WIND SENSITIVE
OPERATIONS MAY BE AFFECTED. PLEASE REFER TO THE WIND ADVISORY FOR
FURTHER DETAILS.

.DAYS TWO THROUGH SEVEN...THRUSDAY THROUGH TUESDAY

SNOW SHOWERS ARE EXPECTED TO DISSIPATE ACROSS THE HIGHER TERRAIN
AND EASTERN UTAH DURING THE DAY THURSDAY.

ACTIVE WEATHER CONTINUES THIS WEEKEND INTO EARLY NEXT WEEK AS
SEVERAL WEATHER DISTURBANCES CROSS THE REGION.

.SPOTTER INFORMATION STATEMENT...

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

ROGOWSKI

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

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
722 PM MDT WED MAR 16 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0700 PM     FLOOD            EDEN                    41.30N 111.82W
03/16/2011                   WEBER              UT   EMERGENCY MNGR

            BASEMENT FLOODING IN SEVERAL HOMES AND STREAMS ARE ALL
            RUNNING HIGH.

&&

LC