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000
FXUS65 KSLC 291131
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
531 AM MDT FRI APR 29 2016

.SYNOPSIS...A LOW PRESSURE SYSTEM WILL CONTINUE TO EXIT THE AREA
TODAY. A SECOND STORM SYSTEM WILL FOLLOW FOR THIS
WEEKEND...MAINTAINING COOL AND UNSETTLED CONDITIONS FOR MUCH OF THE
REGION.

&&

.SHORT TERM (THROUGH 12Z MONDAY)...THE LATEST UPPER LOW TO IMPACT
THE AREA IS NOW CENTERED ALONG THE UTAH/COLORADO BORDER ON ITS WAY
OUT OF THE AREA. HOWEVER...MOISTURE CONTINUES TO WRAP AROUND THE LOW
WITH SHOWERS CONTINUING ALONG THE SPINE OF UTAH AND POINTS EAST.
EASTERLY FLOW ALONG THE NORTHERN PERIPHERY OF THE LOW CONTINUES TO
PRODUCE SOME GUSTY CANYON WINDS ALONG THE WASATCH FROM FROM PARLEYS
CANYON NORTHWARD. AS THE LOW CONTINUES TO MOVE EAST OF THE
AREA...MODELS INDICATE THE SURFACE GRADIENT WEAKENING AND H7 FLOW
TURNING MORE NORTHWESTERLY BY MID-MORNING SO THESE WINDS ARE NOT
EXPECTED TO LAST MUCH LONGER.

WEAK RIDGING WILL VERY BRIEFLY DEVELOP INTO THE AREA TODAY BEFORE
THE NEXT STORM SYSTEM...CURRENTLY OVER THE PACNW COAST...APPROACHES
THE AREA. DESPITE THE RIDGE...LINGERING MOISTURE WILL CONTINUE TO
ALLOW FOR ISOLATED TO SCATTERED SHOWERS THIS AFTERNOON. TEMPERATURES
WILL WARM A BIT FROM YESTERDAYS HIGHS...BUT MOST AREAS WILL REMAIN
COOLER THAN NORMAL.

THE AFOREMENTIONED UPSTREAM STORM IS STILL PROGGED TO CLOSE OFF AS
IT TRACKS SOUTH OVER NEVADA TONIGHT INTO TOMORROW. PRECIPITATION IS
STILL EXPECTED TO DEVELOP ACROSS WESTERN UTAH OVERNIGHT. THE LOW
WILL THEN TRACK EAST ACROSS ARIZONA TOMORROW NIGHT INTO SUNDAY.
ALTHOUGH A FEW SHOWERS CAN BE EXPECTED ACROSS MUCH OF THE AREA WITH
AFTERNOON CONVECTION ON SATURDAY...THE FOCUS OF PRECIPITATION WILL
BE ACROSS SOUTHERN UTAH. THE LOW WILL THEN LIFT NORTHEAST NEAR THE
FOUR CORNERS REGION AS IT WEAKENS SUNDAY AFTERNOON...SHIFTING THE
FOCUS OF PRECIPITATION TO THE EASTERN UTAH ZONES.

BESIDES PRECIPITATION...ANOTHER IMPACT WITH THIS STORM WILL BE
WINDS. MODELS STILL SUPPORT THE IDEA OF A DOWNSLOPE WIND EVENT ALONG
THE WASATCH FRONT SATURDAY EVENING THROUGH SUNDAY WITH A STRONG
PRESSURE GRADIENT AND COLD ADVECTION WITH 40-50KT H7 FLOW ACROSS THE
TERRAIN. HAVE HELD OFF ON ANY WIND HIGHLIGHTS WITH THE MORNING
PACKAGE...BUT IF MODELS CONTINUE TO HOLD FIRM ON THIS
IDEA...HIGHLIGHTS MAY BECOME NECESSARY.

.LONG TERM (AFTER 12 MONDAY)...WE BEGIN THIS LONG TERM PERIOD UNDER
A BROAD TROUGH THAT IS STILL FAIRLY MOIST. HAVE INCREASED POPS
ACROSS MOST OF THE CWA TO ACCOUNT FOR THE MOIST AIR MASS AND CORE OF
TROUGH AXIS STILL MOVING ACROSS DURING THE AFTERNOON. TAIL END OF
TROUGH MOVES ACROSS NORTHERN UTAH AND SOUTHWEST WYOMING TUESDAY. THE
ENTRANCE REGION OF THE JET WILL BE OVER THIS AREA AND THEREFORE
CONTINUED THE THREAT OF SHOWERS. FARTHER SOUTH THE BUILDING RIDGE
SHOULD SQUELCH THE THREAT OF SHOWERS AND HAVE THEREFORE REMOVED THE
POPS.

FINALLY THE RIDGE BUILDS IN ACROSS THE ENTIRE CWA AFTER MIDNIGHT
TUESDAY NIGHT THROUGH THURSDAY NIGHT BRINGING DRY AND MUCH WARMER
CONDITIONS. THE 700 MB TEMPS FORECAST BY THE GFS ARE PLUS 10 DEGREES
AT SLC BY THURSDAY EVENING WHICH SUPPORTS 84 DEGREES BUT MOST
GUIDANCE REMAINS IN THE UPPER 70S. PUSHED TEMPS TO 81 AT SLC AND 77
AT CDC WHICH MAY NOT BE ENOUGH AS SOUTH WINDS SHOULD CREATE GOOD
MIXING.

BROUGHT SOME LOW POPS TO THE REGION ON FRIDAY AS THE EXIT REGION OF
JET AND ABOUT 4 DEGREES C COOLING AT 500 MB SHOULD CREATE LIFT AND
UNSTABLE CONDITIONS BY FRIDAY AFTERNOON. THE EC APPEARS TO BE THE
OUTLIER COMPARED TO THE GFS OPERATIONAL AND ENSEMBLE MEMBERS SO
LEANED IN FAVOR OF THE GFS.

&&

.AVIATION...WINDS AT THE SLC TERMINAL ARE EXPECTED TO REMAIN LIGHT
AND VARIABLE THROUGH ABOUT 15-16Z AFTER WHICH WINDS SHOULD SETTLE IN
FROM THE NORTHWEST. VFR CONDITIONS WILL PREVAIL THROUGH THE TAF
PERIOD.

&&

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

$$

CHENG/STRUTHWOLF

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)




000
FXUS65 KSLC 290222
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
822 PM MDT THU APR 28 2016

.SYNOPSIS...THE UPPER LEVEL LOW PRESSURE SYSTEM APPROACHING THE
FOUR CORNERS REGION LATER TONIGHT WILL CONTINUE INTO THE CENTRAL
PLAINS STATES LATE FRIDAY. A SECOND STORM SYSTEM WILL FOLLOW THIS
WEEKEND...MAINTAINING COOL AND UNSETTLED CONDITIONS FOR MUCH OF
THE REGION.

&&

.DISCUSSION...
WATER VAPOR LOOP SHOWS AN EXPANSIVE CLOSED LOW CENTERED OVER FAR
NORTHERN ARIZONA. AMDAR 400-250MB WIND OBSERVATIONS PLACE A
CYCLONIC 100-125KT JET OVER THE DEEP SOUTHWEST CONUS INTO THE
SOUTHERN ROCKIES. GOES/HRRR/12Z KSLC RAOB INDICATE THE
PRECIPITABLE WATER VALUE RANGES FROM 0.15"-0.35" MOUNTAINS TO
0.50"-0.70" MOST VALLEYS.

WITH THE CLOSED LOW MAKING ITS WAY TOWARD THE FOUR CORNERS
OVERNIGHT...EXPECTING COLD POOL/DEFORMATION CONVECTION TO MAINLY
AFFECT THE SOUTHERN AND EASTERN ZONES. SREF INDICATES THUNDER
CHANCES WANE QUICKLY WITH SUNSET SO KEPT THAT IDEA FROM THE LAST
SHIFT.

HIGH ELEVATION...ABOVE 7500 FT...COULD SEE A QUICK 1-3" OF SNOWFALL
ACROSS THE BOOK CLIFFS...CENTRAL AND SOUTHERN MOUNTAINS.

OTHER STORY THIS EVENING AREA ENHANCED EASTERLY CANYON WINDS FROM
SALT LAKE COUNTY NORTH INTO THE CACHE...WITH A 10MB PRESSURE
GRADIENT FROM RIVERTON TO SALT LAKE CITY. HRRR-3KM ALONG WITH OUR
3KM WRFS INDICATE GUSTS SHOULD REMAIN FAIRLY STEADY JUST BELOW
ADVISORY CRITERIA. LOCALLY HIGHER GUSTS POSSIBLE NEAR FARMINGTON
AT TIMES.

&&

.PREVIOUS DISCUSSION...
THE UPPER LOW TRACKING EAST ALONG THE UTAH/ARIZONA BORDER WILL
SETTLE INTO THE FOUR REGION OVERNIGHT... THEN CONTINUE EAST INTO
THE CENTRAL PLAINS STATES BY LATE FRIDAY. SCATTERED CONVECTION
EAST OF THE ADVANCING LOW WILL LIKELY INCREASE A BIT IN AREAL
COVERAGE THROUGH THIS EVENING.

A SECOND AREA OF ORGANIZED PRECIP WILL LIKELY FORM IN THE STILL
DEFINABLE DEFORMATION AXIS ACROSS WEST-CENTRAL UTAH THROUGH EXTREME
SOUTHWEST WYOMING THIS EVENING. THIS DEFORMATION AXIS HAS BEEN
STRETCHED OUT ACROSS NORTHERN UTAH MUCH OF THE DAY. THIS AXIS IS
BEGINNING TO TILT ALONG THE SOUTHWEST TO NORTHEAST AXIS AS THE UPPER
LOW MOVES EAST ALONG OUR SOUTHERN BORDER. THE DEFORMATION WILL
WEAKEN CONSIDERABLY LATE TONIGHT...LEAVING SCATTERED CONVECTION
CLOSER TO THE LOW CENTER HEADING INTO FRIDAY MORNING.

A BRIEF LULL IN PRECIP WILL OCCUR FRIDAY AS A WEAK SHORTWAVE RIDGE
MOVES INTO THE AREA AHEAD OF A SECOND PACIFIC UPPER LOW SCHEDULED TO
ARRIVE OVER THE WESTERN GREAT BASIN SATURDAY. THIS NEXT FEATURE WILL
TAKE A MORE NORTH TO SOUTH TRACK THROUGH THE BASIN IN RESPONSE TO
STRONG RIDGING JUST OFF THE WEST COAST. THE GLOBAL MODELS HAVE
TRENDED TOWARDS TAKING THE LOW CENTER FURTHER TO THE WEST...WHICH
WOULD SIGNIFICANTLY REDUCE THE AMOUNT OF PRECIP STRETCHING EAST IN
WESTERN UTAH ON SATURDAY.

ONCE THE UPPER LOW SETTLES INTO THE SOUTHERN GREAT BASIN/DESERT
SOUTHWEST LATE IN THE WEEKEND WILL SEE AN INCREASE IN AREAL COVERAGE
OF PRECIP ACROSS MAINLY THE SOUTHERN HALF OF UTAH ON SUNDAY. THIS
PRECIP WILL LIKELY CONTINUE BEYOND THE SHORT RANGE FORECAST PERIOD.

POTENTIAL EXISTS FOR A SIGNIFICANT DOWNSLOPE/CANYON WIND EVENT ALONG
THE WASATCH FRONT/CACHE VALLEY SATURDAY NIGHT/SUNDAY. NEAR 700MB
EASTERLY COLD ADVECTION OUT OF WYOMING WITH SPEEDS RUNNING AROUND 30
TO 40 KTS AND A FAVORABLE NORTHEAST SURFACE PRESSURE GRADIENT WILL
ALMOST CERTAINLY CREATE STRONG CANYON WINDS ALONG THE WASATCH
FRONT/CACHE VALLEY. POTENTIAL DOES EXIST FOR A GENERAL DOWNSLOPE
WIND EVENT WITH TIGHT THETA SURFACE PACKING NEAR THE RIDGETOPS
SATURDAY EVENING WHICH COLLAPSES DOWN THE WEST SLOPES LATE SATURDAY
NIGHT/EARLY SUNDAY. WIND HIGHLIGHTS APPEAR LIKELY WITH EITHER AN
HIGH END ADVISORY OR HIGH WIND WARNING POSSIBLE.

AFTER MORE THAN A WEEK OF UNSETTLED WEATHER WITH A NEAR-CONSTANT
PROGRESSION OF CLOSED LOWS DRIFTING THROUGH THE AREA...IT APPEARS
THERE IS A BREAK ON THE HORIZON STARTING NEXT WEEK. BY SUNDAY
NIGHT...EXTENDED MODELS ARE IN AGREEMENT THAT A CLOSED LOW WILL BE
FILLING AND WEAKENING OVER UTAH. LINGERING MOISTURE AND SLIGHT
INSTABILITY COULD BE ENOUGH FOR A FEW SHOWERS HERE AND THERE MONDAY
AFTERNOON...BUT OTHERWISE THINGS SHOULD BE DRYING OUT STARTING
MONDAY ACROSS UTAH AND SOUTHWEST WYOMING.

GRADUAL RIDGING BEGINS ACROSS THE GREAT BASIN TUESDAY. THE GFS MODEL
DOES INDICATE DAILY AFTERNOON INSTABILITY OVER THE HIGHER TERRAIN OF
UTAH...AS IS TYPICAL FOR THIS TIME OF YEAR. EACH DAY LOOKS
PROGRESSIVELY DRIER AND WARMER...SO EXPECTING MAYBE A FEW SHOWERS
OVER THE HIGHER TERRAIN MONDAY AND TUESDAY GIVING WAY TO JUST A FEW
CUMULUS CLOUDS BY LATER IN THE WEEK.

THE AXIS OF THE RIDGE PUSHES THROUGH AROUND MIDWEEK...BRINGING
TEMPERATURES AROUND 5-10 DEGREES ABOVE AVERAGE. HOWEVER...THE NEXT
ACTIVE PERIOD IS NOT FAR BEHIND. CURRENT IDEA IN THE EXTENDED MODELS
IS TO BRING YET ANOTHER CLOSED LOW THROUGH CALIFORNIA AND INTO THE
GREAT BASIN BY THE END OF THE WORK WEEK...MEANING COOL AND UNSTABLE
CONDITIONS COULD RETURN BY THE END OF THE WORKWEEK AND INTO NEXT
WEEKEND.

&&

.AVIATION...EASTERLY CROSSWINDS WILL CONTINUE TO IMPACT PORTIONS
OF THE SLC TERMINAL RUNWAYS THROUGH AT LEAST 04Z...WITH PERIODIC
EASTERLIES POSSIBLE THROUGH 14Z. OTHERWISE...WINDS SHOULD GENERALLY
TREND TO THE SOUTH-SOUTHEAST AROUND 03Z-05Z. THERE IS A 20 PERCENT
CHANCE THAT CEILINGS COULD DROP BELOW 7000FT OVERNIGHT...BUT IN
GENERAL A BREAK FROM THE SHOWERY ACTIVITY IS EXPECTED THROUGH AT
LEAST 18Z.

&&

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

$$

PUBLIC...ROGOWSKI/CONGER/VAN CLEAVE
AVIATION...SCHOENING

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)




000
FXUS65 KSLC 290222
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
822 PM MDT THU APR 28 2016

.SYNOPSIS...THE UPPER LEVEL LOW PRESSURE SYSTEM APPROACHING THE
FOUR CORNERS REGION LATER TONIGHT WILL CONTINUE INTO THE CENTRAL
PLAINS STATES LATE FRIDAY. A SECOND STORM SYSTEM WILL FOLLOW THIS
WEEKEND...MAINTAINING COOL AND UNSETTLED CONDITIONS FOR MUCH OF
THE REGION.

&&

.DISCUSSION...
WATER VAPOR LOOP SHOWS AN EXPANSIVE CLOSED LOW CENTERED OVER FAR
NORTHERN ARIZONA. AMDAR 400-250MB WIND OBSERVATIONS PLACE A
CYCLONIC 100-125KT JET OVER THE DEEP SOUTHWEST CONUS INTO THE
SOUTHERN ROCKIES. GOES/HRRR/12Z KSLC RAOB INDICATE THE
PRECIPITABLE WATER VALUE RANGES FROM 0.15"-0.35" MOUNTAINS TO
0.50"-0.70" MOST VALLEYS.

WITH THE CLOSED LOW MAKING ITS WAY TOWARD THE FOUR CORNERS
OVERNIGHT...EXPECTING COLD POOL/DEFORMATION CONVECTION TO MAINLY
AFFECT THE SOUTHERN AND EASTERN ZONES. SREF INDICATES THUNDER
CHANCES WANE QUICKLY WITH SUNSET SO KEPT THAT IDEA FROM THE LAST
SHIFT.

HIGH ELEVATION...ABOVE 7500 FT...COULD SEE A QUICK 1-3" OF SNOWFALL
ACROSS THE BOOK CLIFFS...CENTRAL AND SOUTHERN MOUNTAINS.

OTHER STORY THIS EVENING AREA ENHANCED EASTERLY CANYON WINDS FROM
SALT LAKE COUNTY NORTH INTO THE CACHE...WITH A 10MB PRESSURE
GRADIENT FROM RIVERTON TO SALT LAKE CITY. HRRR-3KM ALONG WITH OUR
3KM WRFS INDICATE GUSTS SHOULD REMAIN FAIRLY STEADY JUST BELOW
ADVISORY CRITERIA. LOCALLY HIGHER GUSTS POSSIBLE NEAR FARMINGTON
AT TIMES.

&&

.PREVIOUS DISCUSSION...
THE UPPER LOW TRACKING EAST ALONG THE UTAH/ARIZONA BORDER WILL
SETTLE INTO THE FOUR REGION OVERNIGHT... THEN CONTINUE EAST INTO
THE CENTRAL PLAINS STATES BY LATE FRIDAY. SCATTERED CONVECTION
EAST OF THE ADVANCING LOW WILL LIKELY INCREASE A BIT IN AREAL
COVERAGE THROUGH THIS EVENING.

A SECOND AREA OF ORGANIZED PRECIP WILL LIKELY FORM IN THE STILL
DEFINABLE DEFORMATION AXIS ACROSS WEST-CENTRAL UTAH THROUGH EXTREME
SOUTHWEST WYOMING THIS EVENING. THIS DEFORMATION AXIS HAS BEEN
STRETCHED OUT ACROSS NORTHERN UTAH MUCH OF THE DAY. THIS AXIS IS
BEGINNING TO TILT ALONG THE SOUTHWEST TO NORTHEAST AXIS AS THE UPPER
LOW MOVES EAST ALONG OUR SOUTHERN BORDER. THE DEFORMATION WILL
WEAKEN CONSIDERABLY LATE TONIGHT...LEAVING SCATTERED CONVECTION
CLOSER TO THE LOW CENTER HEADING INTO FRIDAY MORNING.

A BRIEF LULL IN PRECIP WILL OCCUR FRIDAY AS A WEAK SHORTWAVE RIDGE
MOVES INTO THE AREA AHEAD OF A SECOND PACIFIC UPPER LOW SCHEDULED TO
ARRIVE OVER THE WESTERN GREAT BASIN SATURDAY. THIS NEXT FEATURE WILL
TAKE A MORE NORTH TO SOUTH TRACK THROUGH THE BASIN IN RESPONSE TO
STRONG RIDGING JUST OFF THE WEST COAST. THE GLOBAL MODELS HAVE
TRENDED TOWARDS TAKING THE LOW CENTER FURTHER TO THE WEST...WHICH
WOULD SIGNIFICANTLY REDUCE THE AMOUNT OF PRECIP STRETCHING EAST IN
WESTERN UTAH ON SATURDAY.

ONCE THE UPPER LOW SETTLES INTO THE SOUTHERN GREAT BASIN/DESERT
SOUTHWEST LATE IN THE WEEKEND WILL SEE AN INCREASE IN AREAL COVERAGE
OF PRECIP ACROSS MAINLY THE SOUTHERN HALF OF UTAH ON SUNDAY. THIS
PRECIP WILL LIKELY CONTINUE BEYOND THE SHORT RANGE FORECAST PERIOD.

POTENTIAL EXISTS FOR A SIGNIFICANT DOWNSLOPE/CANYON WIND EVENT ALONG
THE WASATCH FRONT/CACHE VALLEY SATURDAY NIGHT/SUNDAY. NEAR 700MB
EASTERLY COLD ADVECTION OUT OF WYOMING WITH SPEEDS RUNNING AROUND 30
TO 40 KTS AND A FAVORABLE NORTHEAST SURFACE PRESSURE GRADIENT WILL
ALMOST CERTAINLY CREATE STRONG CANYON WINDS ALONG THE WASATCH
FRONT/CACHE VALLEY. POTENTIAL DOES EXIST FOR A GENERAL DOWNSLOPE
WIND EVENT WITH TIGHT THETA SURFACE PACKING NEAR THE RIDGETOPS
SATURDAY EVENING WHICH COLLAPSES DOWN THE WEST SLOPES LATE SATURDAY
NIGHT/EARLY SUNDAY. WIND HIGHLIGHTS APPEAR LIKELY WITH EITHER AN
HIGH END ADVISORY OR HIGH WIND WARNING POSSIBLE.

AFTER MORE THAN A WEEK OF UNSETTLED WEATHER WITH A NEAR-CONSTANT
PROGRESSION OF CLOSED LOWS DRIFTING THROUGH THE AREA...IT APPEARS
THERE IS A BREAK ON THE HORIZON STARTING NEXT WEEK. BY SUNDAY
NIGHT...EXTENDED MODELS ARE IN AGREEMENT THAT A CLOSED LOW WILL BE
FILLING AND WEAKENING OVER UTAH. LINGERING MOISTURE AND SLIGHT
INSTABILITY COULD BE ENOUGH FOR A FEW SHOWERS HERE AND THERE MONDAY
AFTERNOON...BUT OTHERWISE THINGS SHOULD BE DRYING OUT STARTING
MONDAY ACROSS UTAH AND SOUTHWEST WYOMING.

GRADUAL RIDGING BEGINS ACROSS THE GREAT BASIN TUESDAY. THE GFS MODEL
DOES INDICATE DAILY AFTERNOON INSTABILITY OVER THE HIGHER TERRAIN OF
UTAH...AS IS TYPICAL FOR THIS TIME OF YEAR. EACH DAY LOOKS
PROGRESSIVELY DRIER AND WARMER...SO EXPECTING MAYBE A FEW SHOWERS
OVER THE HIGHER TERRAIN MONDAY AND TUESDAY GIVING WAY TO JUST A FEW
CUMULUS CLOUDS BY LATER IN THE WEEK.

THE AXIS OF THE RIDGE PUSHES THROUGH AROUND MIDWEEK...BRINGING
TEMPERATURES AROUND 5-10 DEGREES ABOVE AVERAGE. HOWEVER...THE NEXT
ACTIVE PERIOD IS NOT FAR BEHIND. CURRENT IDEA IN THE EXTENDED MODELS
IS TO BRING YET ANOTHER CLOSED LOW THROUGH CALIFORNIA AND INTO THE
GREAT BASIN BY THE END OF THE WORK WEEK...MEANING COOL AND UNSTABLE
CONDITIONS COULD RETURN BY THE END OF THE WORKWEEK AND INTO NEXT
WEEKEND.

&&

.AVIATION...EASTERLY CROSSWINDS WILL CONTINUE TO IMPACT PORTIONS
OF THE SLC TERMINAL RUNWAYS THROUGH AT LEAST 04Z...WITH PERIODIC
EASTERLIES POSSIBLE THROUGH 14Z. OTHERWISE...WINDS SHOULD GENERALLY
TREND TO THE SOUTH-SOUTHEAST AROUND 03Z-05Z. THERE IS A 20 PERCENT
CHANCE THAT CEILINGS COULD DROP BELOW 7000FT OVERNIGHT...BUT IN
GENERAL A BREAK FROM THE SHOWERY ACTIVITY IS EXPECTED THROUGH AT
LEAST 18Z.

&&

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

$$

PUBLIC...ROGOWSKI/CONGER/VAN CLEAVE
AVIATION...SCHOENING

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)




000
FXUS65 KSLC 282213
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
413 PM MDT THU APR 28 2016

.SYNOPSIS...THE UPPER LEVEL LOW PRESSURE SYSTEM APPROACHING THE
FOUR CORNERS REGION LATER TONIGHT WILL CONTINUE INTO THE CENTRAL
PLAINS STATES LATE FRIDAY. A SECOND STORM SYSTEM WILL FOLLOW THIS
WEEKEND...MAINTAINING COOL AND UNSETTLED CONDITIONS FOR MUCH OF
THE REGION.

&&

.SHORT TERM (UNTIL 00Z MONDAY)...THE UPPER LOW TRACKING EAST ALONG
THE UTAH/ARIZONA BORDER WILL SETTLE INTO THE FOUR REGION OVERNIGHT...
THEN CONTINUE EAST INTO THE CENTRAL PLAINS STATES BY LATE FRIDAY.
SCATTERED CONVECTION EAST OF THE ADVANCING LOW WILL LIKELY
INCREASE A BIT IN AREAL COVERAGE THROUGH THIS EVENING.

A SECOND AREA OF ORGANIZED PRECIP WILL LIKELY FORM IN THE STILL
DEFINABLE DEFORMATION AXIS ACROSS WEST-CENTRAL UTAH THROUGH
EXTREME SOUTHWEST WYOMING THIS EVENING. THIS DEFORMATION AXIS HAS
BEEN STRETCHED OUT ACROSS NORTHERN UTAH MUCH OF THE DAY. THIS
AXIS IS BEGINNING TO TILT ALONG THE SOUTHWEST TO NORTHEAST AXIS
AS THE UPPER LOW MOVES EAST ALONG OUR SOUTHERN BORDER. THE
DEFORMATION WILL WEAKEN CONSIDERABLY LATE TONIGHT...LEAVING
SCATTERED CONVECTION CLOSER TO THE LOW CENTER HEADING INTO FRIDAY
MORNING.

A BRIEF LULL IN PRECIP WILL OCCUR FRIDAY AS A WEAK SHORTWAVE RIDGE
MOVES INTO THE AREA AHEAD OF A SECOND PACIFIC UPPER LOW SCHEDULED
TO ARRIVE OVER THE WESTERN GREAT BASIN SATURDAY. THIS NEXT FEATURE
WILL TAKE A MORE NORTH TO SOUTH TRACK THROUGH THE BASIN IN
RESPONSE TO STRONG RIDGING JUST OFF THE WEST COAST. THE GLOBAL
MODELS HAVE TRENDED TOWARDS TAKING THE LOW CENTER FURTHER TO THE
WEST...WHICH WOULD SIGNIFICANTLY REDUCE THE AMOUNT OF PRECIP
STRETCHING EAST IN WESTERN UTAH ON SATURDAY.

ONCE THE UPPER LOW SETTLES INTO THE SOUTHERN GREAT BASIN/DESERT
SOUTHWEST LATE IN THE WEEKEND WILL SEE AN INCREASE IN AREAL
COVERAGE OF PRECIP ACROSS MAINLY THE SOUTHERN HALF OF UTAH ON
SUNDAY. THIS PRECIP WILL LIKELY CONTINUE BEYOND THE SHORT RANGE
FORECAST PERIOD.

POTENTIAL EXISTS FOR A SIGNIFICANT DOWNSLOPE/CANYON WIND EVENT
ALONG THE WASATCH FRONT/CACHE VALLEY SATURDAY NIGHT/SUNDAY. NEAR
700MB EASTERLY COLD ADVECTION OUT OF WYOMING WITH SPEEDS RUNNING
AROUND 30 TO 40 KTS AND A FAVORABLE NORTHEAST SURFACE PRESSURE
GRADIENT WILL ALMOST CERTAINLY CREATE STRONG CANYON WINDS ALONG
THE WASATCH FRONT/CACHE VALLEY. POTENTIAL DOES EXIST FOR A GENERAL
DOWNSLOPE WIND EVENT WITH TIGHT THETA SURFACE PACKING NEAR THE
RIDGETOPS SATURDAY EVENING WHICH COLLAPSES DOWN THE WEST SLOPES
LATE SATURDAY NIGHT/EARLY SUNDAY. WIND HIGHLIGHTS APPEAR LIKELY
WITH EITHER AN HIGH END ADVISORY OR HIGH WIND WARNING POSSIBLE.

.LONG TERM (AFTER 00Z MONDAY...AFTER MORE THAN A WEEK OF
UNSETTLED WEATHER WITH A NEAR-CONSTANT PROGRESSION OF CLOSED LOWS
DRIFTING THROUGH THE AREA...IT APPEARS THERE IS A BREAK ON THE
HORIZON STARTING NEXT WEEK. BY SUNDAY NIGHT...EXTENDED MODELS ARE
IN AGREEMENT THAT A CLOSED LOW WILL BE FILLING AND WEAKENING OVER
UTAH. LINGERING MOISTURE AND SLIGHT INSTABILITY COULD BE ENOUGH
FOR A FEW SHOWERS HERE AND THERE MONDAY AFTERNOON...BUT OTHERWISE
THINGS SHOULD BE DRYING OUT STARTING MONDAY ACROSS UTAH AND
SOUTHWEST WYOMING.

GRADUAL RIDGING BEGINS ACROSS THE GREAT BASIN TUESDAY. THE GFS
MODEL DOES INDICATE DAILY AFTERNOON INSTABILITY OVER THE HIGHER
TERRAIN OF UTAH...AS IS TYPICAL FOR THIS TIME OF YEAR. EACH DAY
LOOKS PROGRESSIVELY DRIER AND WARMER...SO EXPECTING MAYBE A FEW
SHOWERS OVER THE HIGHER TERRAIN MONDAY AND TUESDAY GIVING WAY TO
JUST A FEW CUMULUS CLOUDS BY LATER IN THE WEEK.

THE AXIS OF THE RIDGE PUSHES THROUGH AROUND MIDWEEK...BRINGING
TEMPERATURES AROUND 5-10 DEGREES ABOVE AVERAGE. HOWEVER...THE
NEXT ACTIVE PERIOD IS NOT FAR BEHIND. CURRENT IDEA IN THE EXTENDED
MODELS IS TO BRING YET ANOTHER CLOSED LOW THROUGH CALIFORNIA AND
INTO THE GREAT BASIN BY THE END OF THE WORK WEEK...MEANING COOL
AND UNSTABLE CONDITIONS COULD RETURN BY THE END OF THE WORKWEEK
AND INTO NEXT WEEKEND.

&&

.AVIATION...FOR THE KSLC TERMINAL...EXPECT UNSETTLED CONDITIONS TO
CONTINUE THIS AFTERNOON AND EVENING AS SHOWERS LINGER OVER
NORTHERN UTAH. VFR CONDITIONS WILL CONTINUE THROUGH THE
PERIOD...THOUGH CEILINGS MAY DIP BELOW 7KFT AGL AT TIMES. VICINITY
SHOWERS ARE A POSSIBILITY INTO THE EVENING...WITH A 10 PERCENT
CHANCE OF VICINITY THUNDERSTORMS THIS AFTERNOON. SOME CLEARING
CAN BE EXPECTED TONIGHT AS SHOWERS WIND DOWN...WITH CEILINGS FULLY
LIFTING ABOVE THE 7KFT THRESHOLD TONIGHT. LIGHT NORTHWEST WINDS
ARE EXPECTED TO GIVE WAY TO TYPICAL LAND BREEZES OVERNIGHT.

&&

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

$$

SHORT TERM...CONGER
LONG TERM/AVIATION...VAN CLEAVE

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)




000
FXUS65 KSLC 281630
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
1030 AM MDT THU APR 28 2016

.SYNOPSIS...THE UPPER LEVEL LOW PRESSURE SYSTEM CENTERED OVER
NORTHWEST ARIZONA WILL CONTINUE EAST TO THE FOUR CORNERS REGION
LATER TONIGHT. A SECOND STORM SYSTEM WILL FOLLOW FOR THE UPCOMING
WEEKEND.

&&

.DISCUSSION...TWO AREAS OF ORGANIZED PRECIPITATION ARE IMPACTING
UTAH THIS MORNING. THE FIRST IS A BAND OF GENERALLY LIGHT PRECIP
ALONG A DEFORMATION AXIS ACROSS NORTHERN UTAH. THIS DEFORMATION
WILL GAIN A MORE SOUTHWEST TO NORTHEAST ORIENTATION AS THE UPPER
LOW CURRENTLY OVER NORTHWEST ARIZONA ADVANCES EAST TODAY. THE BAND
OF PRECIP SHOULD HOLD TOGETHER FAIRLY WELL...WITH THE HEAVIEST
PRECIP EXTENDING FROM WEST-CENTRAL UTAH THROUGH SOUTHWEST WYOMING
BY LATE THIS AFTERNOON.

THE SECOND AREA OF ORGANIZED PRECIP IS ASSOCIATED WITH THE UPPER
LOW OVER NORTHWEST ARIZONA THIS MORNING. THE MOIST AND UNSTABLE
AIR MASS ACROSS SOUTHERN/CENTRAL UTAH WORKING WITH A BROAD AREA OF
SYNOPTIC-SCALE LIFT ASSOCIATED WITH UPPER LOW HAS GENERATED
WIDESPREAD LIGHT PRECIP ACROSS THE SOUTHERN/CENTRAL PORTIONS OF
THE STATE. EMBEDDED CONVECTIVE ELEMENTS ARE PRODUCING AREAS OF
MODERATE PRECIP...ESPECIALLY ACROSS THE HIGHER ELEVATIONS WHERE
SEVERAL INCHES OF SNOW COULD ACCUMULATE THROUGH EARLY THIS
EVENING.

THE POSITIONING OF THE UPPER LOW NEAR THE FOUR CORNERS TONIGHT
WILL MAINTAIN WIDESPREAD PRECIP IN THE WRAP AROUND BAND ALONG THE
NORTH AND WEST FLANKS OF THE LOW OVERNIGHT. THE CENTRAL AND
SOUTHERN MOUNTAINS WILL LIKELY SEE ACCUMULATING SNOWS CONTINUE
WITH THE HEAVIEST SNOWS EXPECTED IN THE CENTRAL MOUNTAINS THIS
EVENING.

A BRIEF APPEARANCE OF A SHORTWAVE RIDGE FRIDAY WILL BE FOLLOWED BY
ANOTHER UPPER LOW CROSSING THE WESTERN GREAT BASIN FRIDAY NIGHT.
THE LATEST RUNS OF THE GFS AND ECMWF INDICATE STRONG RIDGING OVER
THE EASTERN PACIFIC WHICH WILL DRIVE THIS SECOND SYSTEM ON A MORE
NORTH TO SOUTH TRAJECTORY THROUGH THE BASIN. WITH LOW TRACKING
FURTHER WEST OVER NEVADA WILL LIMIT THE BEST CHANCE FOR PRECIP TO
FAR WESTERN UTAH FRIDAY NIGHT/EARLY SATURDAY. ONCE THE UPPER LOW
SETS UP OVER EXTREME SOUTHERN NEVADA/NORTHWEST ARIZONA LOOK FOR
WIDESPREAD PRECIP TO RETURN SOUTHERN/CENTRAL UTAH FOR THE WEEKEND.
NORTHERN UTAH WILL RECEIVE SOME PRECIP...THOUGH THE DEEP EAST-
NORTHEAST FLOW ALOFT WILL SOMEWHAT LIMIT THE AREAL COVERAGE AND
INTENSITY OF ANY PRECIP WEST OF THE WASATCH RANGE IN NORTHWEST
UTAH.

ISSUED AN EARLY UPDATE TO INCREASE POPS AND SNOW ACCUMULATIONS FOR
THE SOUTHERN AND CENTRAL MOUNTAINS. ALSO MADE A FEW SHORT TERM
ADJUSTMENTS TO POPS FOR VALLEY LOCATIONS BASED ON THE LATEST HRRR
MODEL.

&&

.AVIATION...FOR THE KSLC TERMINAL...EXPECT UNSETTLED CONDITIONS TO
CONTINUE TODAY WITH OCCASIONAL RAIN SHOWERS AND CEILINGS DROPPING
BELOW 7 THOUSAND FEET AGL AT TIMES. THE WIND FORECAST IS
CHALLENGING THIS MORNING WITH SEVERAL COMPETING FORCES IN THE
ATMOSPHERE. THE OVERALL SYNOPTIC SETUP FAVORS NORTHERLY BREEZES AT
THE SURFACE TODAY. HOWEVER...ONLY A FEW THOUSAND FEET UP...WINDS
SHIFT TO EASTERLY...AND ARE ALSO EASTERLY CLOSER TO THE WASATCH
FRONT. THUS...EXPECTING NORTHERLY WINDS IN GENERAL...WITH A 30
PERCENT CHANCE OF EASTERLY WINDS AT TIMES. ALSO...EXPECTING A BIT
OF WIND SHEAR WITH THE SWITCH TO EASTERLY WINDS OF 15-20 KTS JUST
ABOVE THE GROUND AS SEEN ON THE KMTX WIND PROFILER CURRENTLY.

THERE IS ABOUT A 10 PERCENT CHANCE OF VICINITY THUNDERSTORMS THIS
AFTERNOON...THEN PARTIAL CLEARING LATE TODAY WITH CEILINGS LIFTING
ABOVE THE 7KFT THRESHOLD. SHOWERS SHOULD WIND DOWN BY LATE THIS
EVENING...WITH TYPICAL LAND BREEZES SETTING UP OVERNIGHT.

&&

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

$$

PUBLIC...
AVIATION...

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000
FXUS65 KSLC 281142
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
542 AM MDT THU APR 28 2016

.SYNOPSIS...A PACIFIC STORM SYSTEM WILL CONTINUE SLOWLY EAST ALONG
THE UTAH ARIZONA BORDER THROUGH FRIDAY. A SECOND STORM SYSTEM WILL
SETTLE INTO THE GREAT BASIN SATURDAY AND LINGER OVER THE REGION INTO
EARLY NEXT WEEK.

&&

.SHORT TERM (THROUGH 12Z SUNDAY)...AN UPPER LOW CONTINUES TO SLOWLY
CROSS THE GREAT BASIN THIS MORNING. A COUPLE OF CIRCULATION CENTERS
ARE EVIDENT...ONE OVER WEST-CENTRAL UTAH AND THE SECOND JUST EAST OF
LAKE MEAD. THE NORTHERN FEATURE IS RESPONSIBLE FOR THE ARC OF
PRECIPITATION CURRENTLY EXTENDING ALONG THE I-80 CORRIDOR ACROSS
WESTERN UTAH AND INTO THE UINTA MOUNTAINS. THIS AREA OF
PRECIPITATION IS EXPECTED TO BECOME INCREASINGLY CONFINED TO THE
NORTHWEST AND WEST-CENTRAL DESERTS AS THE EASTERLY FLOW ACROSS THE
WASATCH RANGE BECOMES DEEPER. MEANWHILE...THE SOUTHERN CIRCULATION
IS CURRENTLY SPREADING SHOWERS INTO SOUTH-CENTRAL AND SOUTHEAST
UTAH. THIS AREA OF PRECIPITATION IS EXPECTED TO CONTINUE SPREADING
NORTH ACROSS THE EASTERN VALLEYS AND ADJACENT MOUNTAINS THROUGH THE
DAY AS THE LOW ROTATES NORTHEAST.

BOTTOM LINE IS THAT COOL AND WET WEATHER WILL CONTINUE THROUGH MUCH
OF CENTRAL...SOUTHERN AND EASTERN UTAH TODAY AS THE STORM SYSTEM
SLOWLY TRAVERSES THE AREA. ALTHOUGH A FEW SHOWERS ARE STILL POSSIBLE
ACROSS THE FAR NORTH...WITH THE CENTER OF THE STORM CROSSING
SOUTHERN UTAH AND THE EASTERLY FLOW ALONG ITS NORTHERN
PERIPHERY...THE THREAT OF SHOWERS WILL BE SMALLER THERE. SNOW LEVELS
SHOULD REMAIN IN THE 6500-7500 FT RANGE. THE EASTERLY FLOW WILL
INDUCE SOME CANYON WINDS THIS MORNING ALONG THE WASATCH FRONT...BUT
THESE WINDS ARE NOT EXPECTED TO BE PARTICULARLY STRONG.

THE STORM WILL MOVE EAST OF THE AREA TONIGHT WITH PRECIPITATION
GRADUALLY DIMINISHING THROUGH TOMORROW MORNING. A WEAK SHORTWAVE
RIDGE WILL BUILD IN FOR A FLEETING MOMENT TOMORROW BEFORE THE NEXT
STORM STARTS TO DROP IN FROM THE NORTHWEST. LINGERING MOISTURE
TOMORROW SHOULD ALLOW SOME ISOLATED TO SCATTERED SHOWERS TO DEVELOP
ACROSS THE AREA IN THE AFTERNOON BEFORE LARGE-SCALE LIFT AHEAD OF
THE APPROACHING STORM BRINGS MORE WIDESPREAD PRECIPITATION TO THE
WESTERN VALLEYS TOMORROW EVENING/NIGHT. THIS STORM...ANOTHER CLOSED
LOW...IS FORECAST TO TRACK SOUTH THROUGH NEVADA BEFORE TURNING THE
CORNER NEAR LAKE MEAD SATURDAY EVENING. THE BULK OF THE
PRECIPITATION FOR SATURDAY AND SATURDAY NIGHT WILL FOCUS ALONG THE
SOUTHERN PORTIONS OF THE FORECAST AREA CLOSER TO THE LOW CENTER.

WITH EASTERLY FLOW ONCE AGAIN DEVELOPING NORTH OF THE LOW
CENTER...ANOTHER THREAT OF CANYON/DOWNSLOPE WINDS ALONG THE WASATCH
FRONT WILL BE POSSIBLE BEGINNING SATURDAY NIGHT. BECAUSE THIS LOW IS
FORECAST TO SPIN UP TIGHTER THAN THE PREVIOUS ONE...A STRONGER
PRESSURE GRADIENT LOOKS TO DEVELOP. ALONG WITH AROUND 30-40KT OF
CROSS-BARRIER FLOW AT 700MB AND COLD ADVECTION...THERE IS A
POTENTIAL FOR STRONG GUSTY WINDS. THIS IS SOMETHING WORTH
WATCHING...ALTHOUGH THERE IS NOT MUCH GUARANTEE AT THIS TIME THAT
ALL OF THE PIECES WILL COME TOGETHER.

.LONG TERM (AFTER 12 SUNDAY)...UPPER TROUGH CLOSED OVER NORTHERN
ARIZONA TO BEGIN THE LONG TERM PERIOD WILL CONTINUE TO GRADUALLY
FILL/MODERATE THROUGH SUNDAY. THIS SAID...CONVERGENT MID LEVEL FLOW
ADVERTISED ACROSS SOUTHERN/EASTERN UTAH WILL OWE TO FAIRLY
WIDESPREAD PRECIP COVERAGE THOSE AREAS WITH ISOLATED CONVECTIVE
POTENTIAL EXTENDING ACROSS NORTHERN/WESTERN UTAH. HAVE CONTINUED TO
UP POPS ACROSS THE SOUTHERN MTNS AND EASTERN VALLEYS BY ROUGHLY 10
PERCENT THIS FORECAST.

OF MORE IMPORTANCE TO THE NORTH WILL BE MAINTENANCE OF STRONG
EASTERLY FLOW ALOFT /H7 WINDS 30 TO 40 KNOTS/ COUPLED WITH A MODEST
NE MSLP GRADIENT DRIVING CAA ACROSS THE NORTHERN WASATCH FRONT. WILL
HAVE TO CONTINUE TO MONITOR FOR POTENTIAL OF A MODERATELY STRONG
EASTERLY WIND EVENT THROUGH MUCH OF SUNDAY MORNING AS TIME NEARS.

RIDGING OVER THE NORTHERN ROCKIES REGION WILL AID TO LARGELY FILL
THE TROUGH IN PLACE SUNDAY NIGHT INTO EARLY WEEK. REMNANT ENERGY
COUPLED WITH LINGERING LOW LEVEL MOISTURE WILL LIKELY SPARK ISOLATED
TO WIDELY SCATTERED TERRAIN BASED CONVECTION INTO TUESDAY...THOUGH
NET TRENDS IN BOTH AREAL COVERAGE AND SIGNIFICANCE OF PRECIP WILL BE
ON THE DECLINE WITH A FURTHER RISE OF HEIGHTS ALOFT.

THE MIDWEEK PERIOD WILL BE DOMINATED BY A SIGNIFICANT WARMING OF
TEMPS AS HIGH PRESSURE CONTINUES TO BECOME MORE ESTABLISHED OVER THE
EASTERN GREAT BASIN/NORTHERN ROCKIES REGION. ANTICIPATING TEMPS WILL
RUN WELL ABOVE NORMAL AS SUCH...WITH DRY AND STABLE CONDITIONS
DOMINATING. CARRYING A DRY FORECAST WEDNESDAY/THURSDAY.

&&

.AVIATION...CIGS ARE EXPECTED TO GRADUALLY LOWER BELOW 6000FT AGL AT
THE KSLC TERMINAL BETWEEN 12-15Z AS A BAND OF SHOWERS SPREADS IN
FROM THE SOUTH AND EAST. THESE CIGS ARE EXPECTED TO PREVAIL THROUGH
THE AFTERNOON THOUGH A 60 PERCENT CHANCE EXISTS FOR BRIEF PERIODS OF
IMPROVEMENT. LIGHT SOUTHEAST WINDS IN PLACE ARE EXPECTED TO SWITCH
TO THE NORTH/NORTHEAST EARLIER THAN NORMAL TODAY...MOST LIKELY
BETWEEN 15-17Z AND GRADUALLY INCREASING THROUGH THE AFTERNOON. CIGS
ARE EXPECTED TO THIN/LIFT LATE THIS AFTERNOON AND THROUGH THIS
EVENING.

&&

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

$$

CHENG/MERRILL

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000
FXUS65 KSLC 280357
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
957 PM MDT WED APR 27 2016

.SYNOPSIS...A PACIFIC STORM SYSTEM WILL MOVE INLAND AND ACROSS THE
GREAT BASIN TONIGHT...THEN CONTINUE SLOWLY EAST ALONG THE UTAH
ARIZONA BORDER THROUGH FRIDAY. A SECOND STORM SYSTEM WILL SETTLE
INTO THE GREAT BASIN SATURDAY AND LINGER OVER THE REGION INTO
EARLY NEXT WEEK.

&&

.DISCUSSION...THE LATEST IN A SERIES OF SLOW MOVING PACIFIC
TROUGHS IS CURRENTLY SPREADING ACROSS THE GREAT BASIN...AND WILL
CONTINUE EASTWARD ACROSS THE INTERMOUNTAIN REGION OVERNIGHT
THROUGH THE DAY THURSDAY. A CIRCULATION IS NOTED IN WV IMAGERY
DEVELOPING WITHIN THE BASE OF THIS TROUGH...AND THIS FEATURE IS
FORECAST TO TRACK EAST ALONG THE UT/AZ BORDER THROUGH THURSDAY.
AHEAD OF THIS LOW A REGION OF UPPER DIFFLUENCE IS NOTED ACROSS
CENTRAL AND NORTHERN UT WHERE A BROAD AREA OF SHOWERS HAS FILLED
IN. THIS IS IN ADVANCE OF A BETTER DEFINED SHORTWAVE LIFTING
ACROSS SOUTHWEST UT...WHICH IS FORECAST TO ROTATE THROUGH CENTRAL
UT BEFORE PIVOTING ACROSS NORTHERN UT OVERNIGHT. THIS FEATURE WILL
MAINTAIN/ENHANCE SHOWERS ACROSS MUCH OF THE AREA INTO THE
OVERNIGHT HOURS.

AS THE UPPER LOW ROTATES ALONG THE UT/AZ BORDER THURSDAY THE
PRECIPITATION THREAT WILL BECOME LARGELY FOCUSED ON THE CENTRAL
AND SOUTHERN PORTION OF THE FORECAST AREA...WHILE THE NORTH BEGINS
TO DRY OUT THROUGH THE AFTERNOON HOURS.

CURRENT FORECAST HAS THESE TRENDS WELL HANDLED.

&&

.AVIATION...KSLC WILL FLUCTUATE BETWEEN VFR AND MVFR CONDITIONS
WITHIN RAIN SHOWERS THROUGH THE OVERNIGHT HOURS. WINDS AT THE
TERMINAL WILL REMAIN PREDOMINANTLY SOUTHERLY...BUT COULD BECOME
ERRATIC AT TIMES.

&&

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

$$

SEAMAN

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000
FXUS65 KSLC 272242
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
442 PM MDT WED APR 27 2016

.SYNOPSIS...THE PACIFIC STORM SYSTEM ALONG THE NORTHERN
CALIFORNIA COAST WILL CONTINUE SOUTHEAST INTO THE GREAT BASIN
TONIGHT...THEN TRACK SLOWLY EAST ALONG THE UTAH ARIZONA BORDER
THROUGH FRIDAY. A SECOND STORM SYSTEM WILL SETTLE INTO THE GREAT
BASIN SATURDAY AND LINGER OVER THE REGION INTO EARLY NEXT WEEK.

&&

.SHORT TERM (UNTIL 00Z SUNDAY)...THE UPPER LOW CURRENTLY ALONG THE
NORTHERN CALIFORNIA COAST WILL CONTINUE ON A SOUTHEAST TRACK IN
EXTREME SOUTHERN NEVADA OVERNIGHT. AHEAD OF THIS LOW A VORTICITY
LOBE OVER EXTREME SOUTHWEST UTAH WILL LIFT NORTH ACROSS THE
WESTERN PORTION OF UTAH OVERNIGHT. AN EXPANDING AREA OF CONVECTIVE
PRECIP WILL DEVELOP ALONG THIS FEATURE ACROSS WESTERN UTAH THIS
EVENING...THEN GRADUALLY WIND DOWN OVER SOUTHWEST UTAH LATE
TONIGHT.

ANY BREAK IN PRECIP WILL BE SHORT-LIVED ACROSS SOUTHERN UTAH AS
THE CENTER OF THE UPPER LOW TAKES A POSITION ACROSS EXTREME
SOUTHERN NEVADA EARLY THURSDAY. THIS LOW WILL TAKE A SLOW EASTWARD
TRACK ALONG THE UTAH/ARIZONA BORDER DURING THE DAY. GOOD DYNAMIC
LIFT EAST AND NORTH OF THE LOW CENTER ALONG WITH AN AMBIENT AIR
MASS THAT SHOULD STILL BE SUFFICIENT MOIST AND UNSTABLE WILL
PRODUCE WIDESPREAD PRECIP ACROSS MAINLY THE SOUTHERN HALF OF UTAH
DURING THE DAY.

PRECIP SHOULD LINGER INTO THE EVENING...WITH MOST OF THE REMAINING
ACTIVITY IN THE NORTH AND WEST FLANK OF THE EXITING UPPER LOW.
NORTHERN UTAH/SOUTHWEST WYOMING WILL COME UNDER AN INCREASINGLY
STRONG EASTERLY FLOW ALOFT AS THE UPPER LOW APPROACHES THE FOUR
CORNERS REGION LATE TONIGHT. A STRENGTHENING NORTHEAST SURFACE
GRADIENT OVER WESTERN WYOMING SUPPORTED BY THE EASTERLY FLOW ALOFT
WILL CREATE GUSTY EAST WINDS OVER SOUTHWEST WYOMING...AND SPILLING
INTO FAR NORTHERN UTAH. THE SITUATION WILL BE FAVORABLE FOR CANYON
WINDS THROUGH THE CACHE VALLEY AND NORTHERN WASATCH FRONT.
EXPECTED SPEEDS FOR THE MOST PART WILL BE BELOW ADVISORY LEVELS...
SO NO HIGHLIGHTS ARE ANTICIPATED AT THIS TIME.

A SHORTWAVE RIDGE MOVING INTO UTAH FRIDAY NIGHT WILL GIVE WAY TO A
SECOND STORM SYSTEM ENTERING THE WESTERN GREAT BASIN LATE FRIDAY
NIGHT. THIS SECOND SYSTEM WILL TAKE A MORE NORTH-TO-SOUTH TRACK
THROUGH THE WESTERN GREAT BASIN...WITH THE ASSOCIATED PRECIP
REACHING INTO EXTREME WESTERN UTAH. WIDESPREAD PRECIP WILL LIKELY
HOLD OFF UNTIL THIS FEATURE SETTLES INTO EXTREME SOUTHERN NEVADA
AD SOUTHWEST UTAH DURING THE DAY SATURDAY. LARGE-SCALE SYNOPTIC
LIFT ALONG WITH ABUNDANT MOISTURE SHOULD BRING ABOUT ANOTHER ROUND
OF PRECIP TO MUCH OF SOUTHERN/CENTRAL/EASTERN UTAH BY SATURDAY
AFTERNOON.

.LONG TERM (AFTER 00Z SUNDAY)...IN THE ACTIVE SERIES OF UPPER LEVEL
TROUGH SYSTEMS...THE NEXT CUT OFF LOW SLIDES DOWN NEVADA AND SETTLES
ON THE TRI-STATE AREA (NEVADA/CALIFORNIA/ARIZONA) LATE SATURDAY.
EXTENDED FORECAST MODELS ARE IN AGREEMENT ON THE TRACK OF THIS CUT
OFF LOW TO MOVE EAST ACROSS NORTHERN ARIZONA/SOUTHERN UTAH THROUGH
THE WEEKEND. WITH THE FAR SOUTH TRACK OF THIS CUT OFF SYSTEM...THE
SURFACE PRESSURE GRADIENT FROM WYOMING INTO UTAH BECOMES COMPRESSED
AND THE 700 MB WINDS BECOME BREEZY FOR SUNDAY. ONE ITEM TO KEEP AN
EYE ON AS WE NEAR THE WEEKEND WILL BE AN EASTERLY WIND EVENT.

PRECIPITATION LOOKS TO BE FOCUSED ON THE CENTRAL AND SOUTHERN
PORTIONS OF UTAH THROUGH THE WEEKEND DUE IN PART TO THE SOUTHERN
PLACEMENT OF THE TROUGH. BY THE END OF THE WEEKEND...THE TROUGH
BECOMES AN OPEN WAVE AS DEPICTED ON THE GLOBAL FORECAST MODELS WITH
RIDGING BUILDING IN FROM THE WEST. A STEADY RISE IN 500 MB HEIGHTS
THROUGH LATE TUESDAY SHOULD ALLOW TEMPERATURES ENOUGH OF A WARMING
BIAS TO WARM TO ABOVE NORMAL FOR THIS TIME OF YEAR. IN THE FAR
EXTENDED IT APPEARS ANOTHER DEEP TROUGH WILL MAKE AN APPEARANCE
THROUGH THE GREAT BASIN BY LATE NEXT WEEK.

&&

.AVIATION...FOR THE KSLC TERMINAL...WINDS ARE STRUGGLING TO
SWITCH TO THE NORTH LIKELY DUE TO SHOWERS AND CONVECTION SOUTHWEST
OF THE SALT LAKE VALLEY. A 30 PERCENT CHANCE OF WINDS SWITCHING TO
THE NORTH FOR THE REMAINDER OF THIS AFTERNOON/EVENING. CONVECTION IS
EXPECTED THIS EVENING AGAIN AND TO PERSIST OFF AND ON THROUGH THE
OVERNIGHT HOURS.

&&


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

$$

SHORT TERM...CONGER
LONG TERM/AVIATION...DEWEY

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000
FXUS65 KSLC 271604
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
1004 AM MDT WED APR 27 2016

.SYNOPSIS...THE NEXT PACIFIC STORM SYSTEM WILL MOVE INTO THE GREAT
BASIN TODAY...THEN TRACK SLOWLY EAST ALONG THE UTAH ARIZONA
BORDER THROUGH FRIDAY. A SECOND STORM SYSTEM WILL SETTLE INTO THE
GREAT BASIN SATURDAY AND LINGER OVER THE REGION INTO EARLY NEXT
WEEK.

&&

.DISCUSSION...THE UPPER LOW CURRENTLY POSITIONED ALONG THE
NORTHERN CALIFORNIA COAST WILL CONTINUE SOUTHEAST INTO EXTREME
SOUTHERN NEVADA BY EARLY THURSDAY. FROM THERE THE LOW WILL MOVE
SLOWLY EAST TO THE FOUR CORNERS REGION BY EARLY FRIDAY...THEN
LIFT NORTHEAST THROUGH THE CENTRAL ROCKIES AHEAD OF A SECOND UPPER
LOW SETTLING INTO THE WESTERN/SOUTHERN GREAT BASIN OVER THE
WEEKEND.

LINGERING ISOLATED SHOWERS THIS MORNING WILL INCREASE IN AREAL
COVERAGE THIS AFTERNOON. A VORTICITY LOBE ROTATING NORTH-NORTHEAST
AHEAD OF THE COASTAL CALIFORNIA UPPER LOW WILL SUPPLY THE DYNAMIC
LIFT TO GENERATE AN EXPANDING AREA OF LIGHT/MODERATE PRECIP ACROSS
WESTERN/CENTRAL UTAH LATER THIS AFTERNOON AND INTO THE EVENING
HOURS.

A SHORT BREAK IN PRECIP COULD DEVELOP LATE TONIGHT BEHIND THE
VORTICITY LOBE AND AHEAD OF THE MAIN UPPER LOW SETTLING INTO
SOUTHERN NEVADA. PRECIP WILL ONCE AGAIN INCREASE IN AREAL COVERAGE
AND INTENSITY IN THE AREA OF STRONGEST SYNOPTIC-SCALE LIFT ALONG
THE NORTH AND EAST FLANKS OF THE UPPER LOW AS IT SLOWLY TRACKS
EAST NEAR THE UTAH/ARIZONA BORDER. SUSPECT THE HEAVIEST PRECIP
COULD EXTEND INTO CENTRAL AND NORTHEAST UTAH...THEN RAPIDLY
DECREASE ACROSS THE NORTHERN THIRD OF THE STATE AS A WRAP AROUND
EAST-NORTHEAST FLOW ALOFT DEVELOPS.

THE SECOND UPPER LOW WILL TAKE A SIMILAR TRACK THROUGH THE WESTERN
THEN SOUTHERN GREAT BASIN THIS WEEKEND. CURRENT GUIDANCE INITIALLY
TAKES THIS FEATURE ON A MORE NORTH-TO-SOUTH TRAJECTORY FROM THE
PACIFIC NORTHWEST THROUGH THE WESTERN GREAT BASIN. EVENTUALLY THE
CENTER ENDS UP ACROSS EXTREME SOUTHERN NEVADA BY EARLY SUNDAY.
FROM THERE THE GLOBAL MODELS INDICATE LESS EASTWARD PROGRESSION
AND MORE OF A BROAD UPPER LOW ENCOMPASSING THE MAJORITY OF THE
INTERMOUNTAIN REGION EARLY NEXT. SENSIBLE WEATHER IN THIS PATTERN
WOULD LIKELY BE ONE OF COOL TEMPERATURES AND WIDESPREAD
LIGHT/MODERATE PRECIP EARLY NEXT WEEK.

CURRENT FORECAST APPEARS TO BE IN GOOD SHAPE. NO UPDATE PLANNED.

&&

.AVIATION...SOUTHEAST WINDS ARE EXPECTED TO SWITCH TO THE NORTHWEST
BETWEEN 19-20Z. CONVECTION IS EXPECTED TO BUILD OVER THE LOCAL
TERRAIN ONCE AGAIN THIS AFTERNOON...AND A 40 PERCENT CHANCE EXISTS
THAT CIGS BELOW 6000FT AGL AND RAIN SHOWERS WILL ONCE AGAIN IMPACT
THE TERMINAL LATE THIS AFTERNOON AND ESPECIALLY THIS EVENING AS THE
NEXT LOW SETTLES IN.

&&

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

$$

PUBLIC...CONGER
AVIATION...DEWEY

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000
FXUS65 KSLC 271604
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
1004 AM MDT WED APR 27 2016

.SYNOPSIS...THE NEXT PACIFIC STORM SYSTEM WILL MOVE INTO THE GREAT
BASIN TODAY...THEN TRACK SLOWLY EAST ALONG THE UTAH ARIZONA
BORDER THROUGH FRIDAY. A SECOND STORM SYSTEM WILL SETTLE INTO THE
GREAT BASIN SATURDAY AND LINGER OVER THE REGION INTO EARLY NEXT
WEEK.

&&

.DISCUSSION...THE UPPER LOW CURRENTLY POSITIONED ALONG THE
NORTHERN CALIFORNIA COAST WILL CONTINUE SOUTHEAST INTO EXTREME
SOUTHERN NEVADA BY EARLY THURSDAY. FROM THERE THE LOW WILL MOVE
SLOWLY EAST TO THE FOUR CORNERS REGION BY EARLY FRIDAY...THEN
LIFT NORTHEAST THROUGH THE CENTRAL ROCKIES AHEAD OF A SECOND UPPER
LOW SETTLING INTO THE WESTERN/SOUTHERN GREAT BASIN OVER THE
WEEKEND.

LINGERING ISOLATED SHOWERS THIS MORNING WILL INCREASE IN AREAL
COVERAGE THIS AFTERNOON. A VORTICITY LOBE ROTATING NORTH-NORTHEAST
AHEAD OF THE COASTAL CALIFORNIA UPPER LOW WILL SUPPLY THE DYNAMIC
LIFT TO GENERATE AN EXPANDING AREA OF LIGHT/MODERATE PRECIP ACROSS
WESTERN/CENTRAL UTAH LATER THIS AFTERNOON AND INTO THE EVENING
HOURS.

A SHORT BREAK IN PRECIP COULD DEVELOP LATE TONIGHT BEHIND THE
VORTICITY LOBE AND AHEAD OF THE MAIN UPPER LOW SETTLING INTO
SOUTHERN NEVADA. PRECIP WILL ONCE AGAIN INCREASE IN AREAL COVERAGE
AND INTENSITY IN THE AREA OF STRONGEST SYNOPTIC-SCALE LIFT ALONG
THE NORTH AND EAST FLANKS OF THE UPPER LOW AS IT SLOWLY TRACKS
EAST NEAR THE UTAH/ARIZONA BORDER. SUSPECT THE HEAVIEST PRECIP
COULD EXTEND INTO CENTRAL AND NORTHEAST UTAH...THEN RAPIDLY
DECREASE ACROSS THE NORTHERN THIRD OF THE STATE AS A WRAP AROUND
EAST-NORTHEAST FLOW ALOFT DEVELOPS.

THE SECOND UPPER LOW WILL TAKE A SIMILAR TRACK THROUGH THE WESTERN
THEN SOUTHERN GREAT BASIN THIS WEEKEND. CURRENT GUIDANCE INITIALLY
TAKES THIS FEATURE ON A MORE NORTH-TO-SOUTH TRAJECTORY FROM THE
PACIFIC NORTHWEST THROUGH THE WESTERN GREAT BASIN. EVENTUALLY THE
CENTER ENDS UP ACROSS EXTREME SOUTHERN NEVADA BY EARLY SUNDAY.
FROM THERE THE GLOBAL MODELS INDICATE LESS EASTWARD PROGRESSION
AND MORE OF A BROAD UPPER LOW ENCOMPASSING THE MAJORITY OF THE
INTERMOUNTAIN REGION EARLY NEXT. SENSIBLE WEATHER IN THIS PATTERN
WOULD LIKELY BE ONE OF COOL TEMPERATURES AND WIDESPREAD
LIGHT/MODERATE PRECIP EARLY NEXT WEEK.

CURRENT FORECAST APPEARS TO BE IN GOOD SHAPE. NO UPDATE PLANNED.

&&

.AVIATION...SOUTHEAST WINDS ARE EXPECTED TO SWITCH TO THE NORTHWEST
BETWEEN 19-20Z. CONVECTION IS EXPECTED TO BUILD OVER THE LOCAL
TERRAIN ONCE AGAIN THIS AFTERNOON...AND A 40 PERCENT CHANCE EXISTS
THAT CIGS BELOW 6000FT AGL AND RAIN SHOWERS WILL ONCE AGAIN IMPACT
THE TERMINAL LATE THIS AFTERNOON AND ESPECIALLY THIS EVENING AS THE
NEXT LOW SETTLES IN.

&&

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

$$

PUBLIC...CONGER
AVIATION...DEWEY

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)




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