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000
FXUS65 KSLC 190915
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
315 AM MDT SAT APR 19 2014

.SYNOPSIS...A WEAK SYSTEM WILL REMAIN ACROSS THE REGION THROUGH
THE WEEKEND. A STRONGER STORM WILL IMPACT THE AREA DURING THE
MIDDLE OF NEXT WEEK.

&&

.SHORT TERM (THROUGH 12Z TUESDAY)...
WATER VAPOR LOOP SHOWS A CLOSED LOW NEARING WESTERN ARIZONA. A
RIDGE IS LOCATED OVER THE PACIFIC NORTHWEST WITH THE NEXT STORM
SYSTEM APPROACHING THE COAST. AMDAR 400-250MB WIND OBSERVATIONS
REVEAL A 85- 115KT CYCLONICALLY CURVED JET OVER THE NORTHERN
ROCKIES. GOES/GPS/RAP/00Z RAOB INDICATE THE PRECIPITABLE WATER
VALUE RANGES BETWEEN 0.25" AND 0.65".

DEFORMATION ZONE ASSOCIATED WITH THE ARIZONA SYSTEM WILL PRESENT THE
BEST OPPORTUNITY FOR CONVECTION EAST OF INTERSTATE 15 TODAY. MORNING
SHOWERS ACROSS SOUTHEAST UTAH ARE FORECAST TO EXPAND DUE TO DAYTIME
INSTABILITY THIS AFTERNOON.

MEANWHILE SECOND AREA OF CONVECTION LIKELY TO OCCUR IN THE HIGHER
TERRAIN ALONG THE NEVADA BORDER LATE THIS AFTERNOON CONSIDERING
RIDGING ALOFT BUILDING INTO PLACE WITH SIGNIFICANT REMNANT
MOISTURE IN PLACE. HIGH RESOLUTION LOCAL WRF GUIDANCE INDICATES
THAT THIS CONVECTION MAKES IT EAST ACROSS NORTHERN UTAH
TONIGHT...WHICH SEEMS PLAUSIBLE AHEAD OF THE NEXT COOL FRONT.
GREATEST POPS FOR THE WASTACH FRONT ARE THEREFORE THIS EVENING.

NEXT NORTHERN ROCKIES WAVE SATURDAY NIGHT WILL PROMPT A SHALLOW COLD
FRONT ACROSS NORTHERN AND INTO CENTRAL UTAH SUNDAY. WITH REMNANT
MOISTURE IN PLACE...KEPT MENTION OF CONVECTION ALONG AND AHEAD OF
THIS FEATURE...WITH PLENTY OF DRYING EXPECTED ACROSS THE NORTH.
DOWNSLOPE WINDS WILL LIKELY BE SOMEWHAT ENHANCED SUNDAY AFTERNOON
AND NIGHT ACROSS FAVORED LOCATIONS OF EAST CENTRAL AND SOUTHERN
UTAH.

RETURN FLOW SETS UP QUICKLY MONDAY WITH A BROAD SIGNIFICANT STORM
DEVELOPING OVER THE EASTERN PACIFIC. GUIDANCE REMAINS IFFY REGARDING
CONVECTIVE POTENTIAL ACROSS THE NORTH ASSOCIATED WITH THE APPROACH
OF THE WARM FRONT. KEPT ISOLATED POPS FOR THE NORTHERN TERRAIN.

OTHERWISE WARM SOUTH WINDS DEVELOP MONDAY AFTERNOON AND INCREASE
MONDAY NIGHT. COULD SEE OUR FIRST 80 DEGREE DAY AT SLC MONDAY.
RAISED TEMPERATURES ABOVE GUIDANCE MONDAY NIGHT AHEAD OF A SHARP
COLD FRONT...WHICH ARE LIKELY STILL TOO COOL.

&&

.LONG TERM (AFTER 12Z TUESDAY)...
SOUTHWEST FLOW OVER THE FORECAST AREA IS PROGGED TO INCREASE
DRAMATICALLY DURING THE DAY TUESDAY AS THE NEXT PACIFIC STORM
SYSTEM APPROACHES WITH GFS AND ECMWF INDICATING 700 MB FLOW IN
EXCESS OF 50 KTS JUST AHEAD OF THE FRONTAL BOUNDARY. THESE
CONDITIONS LOOK TO COME DURING PEAK DAYTIME HEATING...WHICH IS
QUITE FAVORABLE FOR A HIGH WIND EVENT OVER MUCH OF THE STATE.

THE FRONT IS EXPECTED TO GO THROUGH NORTHERN UTAH TUESDAY EVENING
AND THROUGH THE REST OF THE STATE TUESDAY NIGHT/WEDNESDAY
MORNING...RESULTING IN A DRAMATIC COOLDOWN. MODELS SHOW 700 MB TEMPS
DROPPING FROM THE +7C TO +9C RANGE AHEAD OF THE BOUNDARY TO -8C TO
-10C BEHIND IT. THE TROUGH BRINGS GOOD DYNAMICS OVER NORTHERN AND
CENTRAL UTAH ALONG AND BEHIND THE FRONT. HOWEVER...MOISTURE
APPEARS TO BE THE LIMITING FACTOR WITH RESPECT TO SIGNIFICANT
PRECIP. STILL...HAVE INCREASED POPS WITH INCREASED CONFIDENCE OF
THE TRACK AND TIMING OF THE INITIAL TROUGH.

BY WEDNESDAY NIGHT...THE TROUGH IS EXPECTED TO EXIT THE AREA AND
THIS IS WHEN GUIDANCE BEGINS TO DIVERGE. GFS IS SHOWING A TRAILING
TROUGH MOVING THROUGH THAT BRINGS A REINFORCING SHOT OF COLD AIR AND
SOME ADDITIONAL PRECIPITATION. MEANWHILE...THE ECMWF INDICATES
RIDGING MOVING BACK IN DURING THIS TIME. BY FRIDAY...HIGH PRESSURE
IS IN PLACE IN ALL SOLUTIONS. AFTER THAT...THERE ARE SOME
INDICATIONS THAT UNSETTLED WEATHER WILL RETURN FOR NEXT WEEKEND.

&&

.AVIATION...VFR CONDITIONS ARE EXPECTED AT THE SLC TERMINAL
THROUGHOUT THE DAY WITH MOSTLY CLOUDY SKIES. LIGHT SOUTHEAST WINDS
ARE EXPECTED TO SHIFT TO THE NORTHWEST BETWEEN 17Z AND 19Z. THERE IS
A 30 PERCENT CHANCE THAT SHOWERS IN THE VICINITY OF THE TERMINAL
WILL RESULT IN PERIODS OF GUSTY AND/OR ERRATIC WINDS THIS
AFTERNOON AND EVENING.

&&

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

$$

SHORT TERM...ROGOWSKI
LONG TERM/AVIATION...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)





000
FXUS65 KSLC 190245
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
845 PM MDT FRI APR 18 2014

.SYNOPSIS...A WEAK SYSTEM WILL REMAIN ACROSS THE REGION THROUGH
THE WEEKEND. A STRONGER STORM WILL IMPACT THE AREA DURING THE
MIDDLE OF NEXT WEEK.

&&

.DISCUSSION...A LOW AMPLITUDE SHORT WAVE TROF IS MOVING OUT OF THE
ROCKIES AND INTO THE NRN PLAINS THIS EVE WHILE A WEAK CLOSED LOW
OVER SRN CA TRACKS SLOWLY EAST. THE NRN BRANCH TROF SENT A SHALLOW
COLD FRONT INTO NRN UT THAT IS STALLED NEAR A DELTA TO PRICE LINE
THIS EVE. NARROW BANDS OF RAIN DEVELOPED NORTH OF THIS FRONT
TODAY BUT HAVE PRETTY MUCH DISSIPATED. SOME ISOLATED WEAK
CONVECTION SPREAD INTO THE NWRN DESERTS FROM ERN NV LATE IN THE
DAY AND A FEW OF THESE SHOWERS PERSIST THIS EVE BUT DO NOT EXPECT
THEM TO LAST PAST MIDNIGHT.

THE CLOSED LOW HAS SPREAD CONVECTIVE SHOWERS INTO SRN UT BUT IT IS
LIKELY THAT NOT MUCH RAIN IS REACHING THE GROUND DUE TO DRY LOW
LEVELS. EXPECT THESE SHOWERS TO INCREASE OVERNIGHT AS ADDITIONAL
MOISTURE AND LIFT SPREADS INTO SRN UT AHEAD OF THE LOW AND THEY
SHOULD START TO REACH THE SURFACE AS THE LOW LEVELS MOISTEN UP
LATER TONIGHT.

THESE SHOULD EXIT THE CWA TOMORROW MORNING BUT EXPECT SCATTERED
CONVECTION TO FIRE DURING THE AFTN...MAINLY OVER HIGHER TERRAIN.
THE FLOW ALOFT IS VERY WEAK SO DONT EXPECT THESE SHOWERS TO MOVE
TOO FAR FROM WHERE THEY FORM BEFORE DISSIPATING. ANOTHER ROUND OF
DIURNAL CONVECTION IS EXPECTED SUN BUT RIDGING WILL BE MOVING INTO
THE AREA DURING THE DAY AND THIS WILL WORK AGAINST THE CONVECTION
KEEPING IT MORE ISOLATED.

THE RIDGE AXIS SHIFTS EAST MON AND THE AIRMASS WARMS STRONGLY
UNDER AN INCREASING SWLY FLOW. THIS FLOW BECOMES STRONG TUE WITH
A GOOD CHANCE OF WARNING LEVEL SOUTHERLY WINDS AHEAD OF A STRONG
COLD FRONT. EQUALLY STRONG WINDS ARE ALSO POSSIBLE BEHIND THIS
FRONT ACROSS THE SALT FLATS AND INTO THE WASATCH FRONT DURING THE
AFTN/EARLY EVE.

UPDATED FORECASTS EARLIER TO ADJUST POPS AND SKY A BIT BUT MADE NO
MAJOR CHANGES. NO ADDITIONAL UPDATES PLANNED.

&&

.AVIATION...NORTHERLY WINDS WILL CONTINUE AT THE SLC TERMINAL
THROUGH AROUND AROUND 05Z THEN BECOME LIGHT SOUTHERLY OR LIGHT AND
VARIABLE. THERE IS A 30 PERCENT CHANCE THAT WINDS REMAIN
LIGHT NORTHERLY THROUGH 08-09Z. VFR CONDITIONS WILL PREVAIL WITH
CIGS REMAINING ABV 7000 FT.

&&

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

$$

WILENSKY

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 182153
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
353 PM MDT FRI APR 18 2014

.SYNOPSIS...A PAIR OF STORM SYSTEMS WILL IMPACT THE REGION THROUGH
THE WEEKEND. A STRONGER STORM WILL IMPACT THE AREA DURING THE
MIDDLE OF NEXT WEEK.

&&

.SHORT TERM (THROUGH 00Z TUESDAY)...THE SURFACE COLD FRONT HAS
TRACKED TO JUST NORTH OF NEPHI AND APPEARS TO BE STALLING OUT.
SHALLOW LOW LEVEL INSTABILITY COMBINED WITH DAYTIME HEATING HAS
RESULTED IN CONVECTION OFF THE MOUNTAINS OF EASTERN NEVADA
NORTHEAST TO THE LOGAN AREA IN WAKE OF ITS PASSAGE BUT LITTLE TO
NO LIGHTNING. EXPECT LOSS OF HEATING SHOULD ALLOW THESE SHOWERS
TO GRADUALLY DISSIPATE THROUGH THE LATE EVENING HOURS TONIGHT. BOTH
THE HIGHER-RES AND GLOBAL MODELS SUGGEST AND HAVE REDUCED POPS AS
A RESULT.

CLOSED UPPER LOW OVER SOCAL NOTED IN AFTERNOON SATELLITE IMAGERY
WILL BE THE PRIMARY WEATHER PRODUCER IN THE SHORT TERM AS IT
TRACKS NORTHEAST THROUGH THE 4-CORNERS REGION OVER THE NEXT 36
HOURS...THIS AS MORE OF AN OPEN WAVE. ALREADY SEEING AN INFLUX OF
MID AND HIGH LEVEL MOISTURE ACROSS THE SOUTH AS IT SLOWLY GRINDS
CLOSER TO THE AREA BUT EXPECT LITTLE IF ANY PRECIP WILL MAKE IT TO
THE GROUND UNTIL LATER TONIGHT. INCREASED UPPER DIVERGENCE OVER
THE SOUTHERN HALF AND FORMATION OF A WEAK DEFORMATION ACROSS
CENTRAL UTAH WILL BE THE PRIMARY LIFTING MECHANISMS AT THAT TIME.

AREAL COVERAGE OF PRECIP LOOKS TO BE THE GREATEST TOMORROW
AFTERNOON AS WEAK FORCING FROM THE SOUTHERN BRANCH WAVE AND
DIURNAL DESTABILIZATION OCCUR. WITH PWATS ON THE ORDER OF .6
INCHES COULD SEE SOME MODERATE RAINERS ACROSS THE SOUTH AND
EAST...AND ISOLATED STORMS ALL AREAS BUT THE NORTHERN WASATCH
FRONT. SNOW LEVELS WILL STRUGGLE TO FALL BELOW 8500 FT BUT COULD
BRIEFLY IN A MORE CONVECTIVE TYPE CELL.

DOWNSTREAM PROGRESSION OF THE TROUGH WILL RESULT IN LOSS OF
DYNAMIC SUPPORT SATURDAY NIGHT AND EXPECT MOST IF NOT ALL
CONVECTION WILL DISSIPATE DURING THE EVENING. A VERY WEAK WAVE
COMBINED WITH REMNANT LOW LEVEL MOISTURE AND INSTABILITY WILL
PROMOTE MORE AFTERNOON CONVECTION ON SUNDAY BUT FLOW DOES LOOK TO
BE TRENDING ANTICYCLONIC HAMPERING DEVELOPMENT. CHANCE POPS
FOCUSED OVER THE TERRAIN FOR THE TIME BEING...WITH DRYING
CONDITIONS MONDAY AS YET ANOTHER SHORT WAVE RIDGE SHIFTS OVERHEAD.

&&

.LONG TERM (AFTER 00Z TUESDAY)...RIDGE AXIS SHOULD BE OVER COLORADO
BY THIS TIME. GFS AND ECMWF AGREE WITH THIS AND WITH SOUTHWEST WINDS
BEGINNING TO INCREASE. THIS IS AHEAD OF A DEVELOPING TROUGH MOVING
EASTWARD. MODELS ARE IN GENERAL AGREEMENT WITH THE TIMING OF THIS
SYSTEM...WHICH IS A BIT UNUSUAL OUT FOUR DAYS. BOTH MODELS ARE ALSO
PRETTY CLOSE WITH THE STRENGTH. EXTREME SOUTHERN UTAH WILL BE THE
LEAST FAVORABLE AREA FOR SHOWERS AS PER BOTH MODELS. TEMPERATURES
ABOVE NORMAL LEVELS ARE EXPECTED MONDAY INTO TUESDAY...WITH HOTTEST
DAY OF THE YEAR NOT OUT OF THE QUESTION ON TUESDAY. THESE WARM
TEMPERATURES WILL COME TO AN END WEDNESDAY. GOOD STRONG SOUTHWEST
FLOW AHEAD OF THIS SYSTEM WILL PUT UTAH UNDER WINDY CONDITIONS LATER
TUESDAY INTO WEDNESDAY. MAY NEED WIND HEADLINES AS A PERIOD OF VERY
STRONG WINDS...WITH GUSTS IN EXCESS OF 60 MPH MAY BE POSSIBLE
TUESDAY. TO REITERATE...THIS EVENT LOOKS LIKE IT HAS THE POTENTIAL
TO BE A HIGH END WIND EVENT. THIS SYSTEM WILL ALSO BE RATHER SLOW
MOVING AND WILL LIKELY IMPACT THE AREA THROUGH THURSDAY. A RIDGE IS
EXPECTED FOR FRIDAY WITH ANOTHER SYSTEM POSSIBLE FOR THE
WEEKEND...ALTHOUGH NOT TOO CONFIDENT OUT THAT FAR.

&&

.AVIATION...BREEZY NORTHERLY WINDS WILL CONTINUE AT THE SLC TERMINAL
THROUGH AROUND AROUND 05Z. THERE IS A 30 PERCENT CHANCE THAT WINDS
REMAIN NORTHERLY LONGER. A FEW SHOWERS WILL BE POSSIBLE IN THE
VICINITY OF THE TERMINAL BEHIND THE COLD FRONT THROUGH EARLY
EVENING. THESE COULD BRING GUSTY AND ERRATIC WINDS TO THE
TERMINAL...BUT SHOULD NOT CAUSE ANY SIGNIFICANT PRECIPITATION.

&&

&&

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

$$

MERRILL/YOUNG


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 181643
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
1043 AM MDT FRI APR 18 2014

.SYNOPSIS...A PAIR OF STORM SYSTEMS WILL IMPACT THE REGION THROUGH
THE WEEKEND. A STRONGER STORM WILL IMPACT THE AREA DURING THE
MIDDLE OF NEXT WEEK.


&&

.DISCUSSION...SURFACE ANALYSIS PLACES A WEAK COLD FRONT FROM
ROUGHLY SALT LAKE CITY TO TOOELE TO DUGWAY. HAVE LIKELY ALREADY
REACHED DAYTIME MAXES FROM SALT LAKE NORTH SO LOWERED TEMPS A FEW
DEGREES FOR THOSE AREAS THAT NOW RESIDE IN THE POST FRONTAL
ENVIRONMENT. THE PARENT SHORT WAVE OF THIS FRONT IS SPINNING ALONG
THE US/CANADA BORDER SO IT REMAINS QUITE REMOVED...AND THE
BOUNDARY ITSELF IS AND WILL REMAIN QUITE SHALLOW. STILL...WEAK
DYNAMIC FORCING HAS PRODUCED NUMEROUS SHOWERS OVER THE NORTHWEST
THIS MORNING. SREF CONTINUES TO SUPPORT MUCAPE VALLEYS OF 100-200
J/KG THIS AFTERNOON ALONG AND BEHIND THE FRONT SO AREAL COVERAGE
SHOULD ONLY INCREASE. BEST PRECIP FOCUSED ALONG THE UT/ID BORDER.

THIS FRONT SHOULD MAKE IT TO ROUGHLY NEPHI BY LATE DAY BEFORE
STALLING AND WASHING OUT OVER THE NEXT 12 TO 18 HOURS.

SPC SREF INSTABILITY FORECASTS HAVE BACKED OFF ON AFTERNOON
CONVECTIVE POTENTIAL ACROSS THE SOUTH...AND DYNAMIC INFLUENCE OF
THE CLOSED CIRCULATION OVER SOCAL DOES NOT LOOK TO MOVE INTO THIS
REGION UNTIL TONIGHT. STILL EXPECTING SOME BUILDUPS OVER THE HIGH
TERRAIN THIS AFTERNOON AS DECENT SURFACE HEATING IS TAKING
PLACE...BUT REMOVED MENTION OF ISOLATED STORMS FOR THE SOUTHERN
VALLEYS/DESERT.

NO OTHER UPDATES OR CHANGES TO THE SHORT TERM FORECAST OUTSIDE OF
THOSE MENTIONED ABOVE.

LONG RANGE WILL CONTINUE TO FOCUS ON A STRONG PACIFIC TROUGH THAT
WILL BEGIN IMPACTING THE AREA TUESDAY. DETAILS IN GUIDANCE
CONTINUE TO WAFFLE REGARDING TIMING AND STRENGTH OF THE ASSOCIATED
COLD FRONT...BUT SEVERAL RUNS OF BOTH THE GFS/ECMWF HAVE SHOWN THE
POTENTIAL FOR A HIGH WIND EVENT FOR AT LEAST PORTIONS OF THE
FORECAST AREA TUESDAY AFTERNOON.

&&

.AVIATION...A COLD FRONT JUST MOVED THROUGH THE KSLC TERMINAL SO
WINDS WILL REMAIN NORTHWESTERLY FOR THE REMAINDER OF THE
DAY...AND WILL BECOME GUSTY FOR MUCH OF THE AFTERNOON. A FEW
SHOWERS WILL BE POSSIBLE IN THE VICINITY OF THE TERMINAL BEHIND
THE COLD FRONT. THESE COULD BRING GUSTY AND ERRATIC WINDS TO THE
TERMINAL.

&&

&&

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

$$

MERRILL/YOUNG


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 180845
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
245 AM MDT FRI APR 18 2014

.SYNOPSIS...A PAIR OF STORM SYSTEMS WILL IMPACT THE REGION THROUGH
THE WEEKEND. A STRONGER STORM WILL IMPACT THE AREA DURING THE
MIDDLE OF NEXT WEEK.

&&

.SHORT TERM (THROUGH 12Z MONDAY)...
WATER VAPOR LOOP SHOWS A RIDGE OVER THE ROCKIES WITH THE NEXT
TROUGH ALONG THE WEST COAST. AMDAR 400-250MB WIND OBSERVATIONS
REVEAL A 100- 135KT CYCLONICALLY CURVED JET OFF THE NORTHWEST
PACIFIC COAST...TRANSLATING TO AN ANTICYCLONICALLY CURVED JET OVER
THE NORTHERN ROCKIES. GOES/GPS/RAP/00Z RAOB INDICATE THE
PRECIPITABLE WATER VALUE RANGES BETWEEN 0.17" AND 0.54".

BEST CHANCE FOR SHOWERS TODAY WILL BE IN THE COOL SECTOR ACROSS
NORTHERN UTAH...THOUGH ENOUGH MOISTURE FROM A SOUTHERN CALIFORNIA
CLOSED LOW WILL ALLOW CONVECTION IN THE CENTRAL AND SOUTHERN
MOUNTAINS DURING THE AFTERNOON. COPIOUS CLOUDS DEVELOP AND THICKEN
THROUGH TONIGHT. HIGH TEMPERATURES WILL BE EARLIER IN THE DAY ACROSS
THE NORTH OWING TO A MORNING COLD FRONTAL PASSAGE. GUSTY SOUTHWEST
WINDS AHEAD OF THE COLD FRONT GIVEN STRENGTHENING PRESSURE
GRADIENT AND 30KT OF SOUTHWEST FLOW AT 700MB.

FRONTAL BOUNDARY SETTLES INTO CENTRAL UTAH TONIGHT...WITH FURTHER
MOISTURE ADVECTION OCCURRING ACROSS SOUTHEAST UTAH. BUMPED UP POPS
AHEAD OF SLOW-MOVING WEAKENING ARIZONA LOW THROUGH SATURDAY
MORNING...WITH DIVERGENCE ALOFT SPREADING NORTHWARD OVER SOUTHERN
UTAH.

WHILE THE REMNANT OF THE ARIZONA LOW CONTINUES TO WEAKEN AND LIFT
THROUGH SOUTHEAST UTAH SATURDAY AFTERNOON...RIDGING BEGINS TO BUILD
ACROSS WESTERN UTAH. WITH THINNING CLOUDS AND NOT A LOT OF
SUBSIDENCE YET...BELIEVE FAIRLY WIDESPREAD CONVECTION WILL DEVELOP
ESPECIALLY SOUTH OF INTERSTATE 80 DURING THE AFTERNOON AND EVENING
HOURS...GIVEN THE AMBIENT MOISTURE IN PLACE. DEPENDING HOW SLOWLY
THE SOUTHERN FEATURE MOVES THROUGH...DEFORMATION ZONE COULD BE IN
THE VICINITY OF OUR EASTERN ZONES DURING PEAK HEATING...THUS RAISED
POPS ONCE AGAIN.

NEXT NORTHERN ROCKIES WAVE SATURDAY NIGHT WILL PROMPT A SHALLOW COLD
FRONT ACROSS NORTHERN AND INTO CENTRAL UTAH SUNDAY. WITH REMNANT
MOISTURE IN PLACE...KEPT MENTION OF CONVECTION ALONG AND AHEAD OF
THIS FEATURE...WITH PLENTY OF DRYING EXPECTED ACROSS THE FAR NORTH.

SPC THUNDER GUIDANCE FROM SHORT RANGE ENSEMBLES INDICATE POTENTIAL
EACH AFTERNOON THROUGH SUNDAY.

&&

.LONG TERM (AFTER 12Z MONDAY)...
A FAIRLY STRONG RIDGE WILL BEGIN THE LONG RANGE FORECAST
PERIOD...WITH TEMPERATURES ABOVE NORMAL LEVELS MONDAY INTO
TUESDAY. BY TUESDAY...IT IS NOT OUT OF THE REALM OF POSSIBILITIES
THAT THE WASATCH FRONT WILL SEE TEMPERATURES MAX OUT AROUND 80F.
THESE WARM TEMPERATURES WILL COME TO A RATHER ABRUPT END ON
WEDNESDAY.

FOR SEVERAL DAYS...GLOBAL MODELS HAVE BEEN ADVERTISING A
LARGE...COLD PACIFIC TROUGH THAT WOULD IMPACT THE WESTERN UNITED
STATES...THOUGH THE DETAILS HAVE BEEN SOMEWHAT INCONSISTENT. MODEL
TO MODEL CONSISTENCY HAS IMPROVED WITH THE 00Z MODEL RUNS.
DIFFERENCES REMAIN IN THE SPECIFIC DETAILS AS IS TYPICAL FOR THE MID
TO LONG RANGE PORTION OF THE FORECAST.

THE 00Z GFS BRINGS A COLD...NEGATIVELY TILTED TROUGH THROUGH THE
GREAT BASIN TUESDAY INTO WEDNESDAY...KEEPING THE SYSTEM LARGELY IN
PLACE UNTIL AN UPSTREAM WAVE DISLODGES THE TROUGH AND FINALLY MOVES
THE SYSTEM OUT OF THE NORTHERN ROCKIES THURSDAY. THE 00Z EC FAVORS
A MORE CONSOLIDATED...NEGATIVELY TILTED SOLUTION THAT IS FAR MORE
PROGRESSIVE THAN THE GFS. THUS...CONFIDENCE IN SPECIFIC TIMING OF
VARIOUS FEATURES IS A BIT ON THE LOW SIDE. DECREASED POPS ACROSS
SOUTHERN UTAH AS IT IS LOOKING MORE AND MORE LIKELY THAT ANY
PRECIPITATION WILL BE MAINLY ACROSS THE NORTHERN HALF OF UTAH.

THE MAIN TAKEAWAYS REGARDING THE IMPACT OF THIS SYSTEM WILL BE
TEMPERATURES AND WIND. VERY WARM TEMPERATURES CAN BE EXPECTED MONDAY
AND TUESDAY AHEAD OF THIS SYSTEM...APPROACHING RECORD LEVELS FOR
SOME PARTS OF THE WASATCH FRONT BY TUESDAY. MUCH COLDER
TEMPERATURES WILL BE FELT IN MANY LOCATIONS BY WEDNESDAY AND THE
COOL TEMPERATURES WILL LIKELY REMAIN IN PLACE THROUGH THE
REMAINDER OF THE FORECAST PERIOD.

THE BIGGEST IMPACT WILL LIKELY BE A PERIOD OF VERY STRONG
WINDS...WITH GUSTS IN EXCESS OF 60 MPH POSSIBLE TUESDAY MORNING INTO
TUESDAY NIGHT. ANYONE TRAVELING OR IMPACTED BY STRONG WINDS SHOULD
CONTINUE TO MONITOR FUTURE FORECASTS AS THIS EVENT LOOKS LIKE IT HAS
THE POTENTIAL TO BE A HIGH END WIND EVENT.

ANOTHER LARGE COLD PACIFIC TROUGH IS FORECAST BY BOTH THE 00Z EC AND
00Z GFS TOWARD THE END OF THE MODEL RUN...IMPACTING THE AREA NEXT
WEEKEND. DEFINITELY SOMETHING TO KEEP AN EYE ON...BUT CONFIDENCE IS
QUITE LOW AT THIS TIME.

&&

.AVIATION...GUSTY SOUTHERLY WINDS WILL CONTINUE AT THE SLC TERMINAL
THROUGH THE MORNING HOURS. A COLD FRONT IS EXPECTED TO CROSS THE
TERMINAL BETWEEN 16-18Z...SHIFTING WINDS TO THE NORTHWEST. WINDS
WILL REMAIN GUSTY THROUGH MUCH OF THE AFTERNOON. A FEW SHOWERS WILL
BE POSSIBLE IN THE VICINITY OF THE TERMINAL NEAR AND BEHIND THE COLD
FRONT. THESE COULD BRING GUSTY AND ERRATIC WINDS TO THE TERMINAL.

&&

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

$$

SHORT TERM...ROGOWSKI
LONG TERM/AVIATION...KRUSE

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 180405
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
1005 PM MDT THU APR 17 2014

.SYNOPSIS...A WEAKENING STORM SYSTEM WILL CROSS THE REGION LATE
FRIDAY THROUGH SATURDAY. A STRONGER STORM WILL IMPACT THE AREA
DURING THE MIDDLE OF NEXT WEEK.

&&

.DISCUSSION...THE AXIS OF THE UPPER RIDGE IS SHIFTING ACROSS THE
CWA THIS EVE AND HIGH CLOUDS ARE INCREASING IN ITS WAKE AHEAD OF
THE SPLITTING TROF ALONG THE WEST COAST. THE AXIS OF THE WARMEST
AIR ALOFT ALSO PASSES TONIGHT AND THE AIRMASS STARTS COOLING
ACROSS THE NORTH DURING THE DAY AS THE NRN BRANCH WAVE SENDS A
DYING COLD FRONT INTO NRN UT.

COOLING ALSO BEGINS ACROSS SRN UT TOMORROW AFTN AS THE SRN BRANCH
LOW STARTS TO LIFT NEWD. PRECIP ALONG THE NRN COLD FRONT LOOKS
LIKE IT DOES NOT REMAIN ORGANIZED VERY WELL PAST NOON BUT A BETTER
ORGANIZED BAND APPEARS TO SWING UP ACROSS SRN UT TOMORROW NIGHT.

RESIDUAL MOISTURE AND INSTABILITY KEEP A THREAT OF CONVECTION
GOING SAT AND ACROSS THE SOUTH SUNDAY SOUTH OF A WEAK DRY FRONT.

SWLY FLOW PICKS UP MON AND THE THREAT OF CONVECTION SHIFTS INTO
THE NRN CWA.

THE 18Z GFS WAS STILL INDICATING A STRONG COLD FRONT FOR TUE AFTN
AHEAD OF A DEEP COLD PAC TROF WITH STRONG SWLY FLOW AHEAD OF IT
TUE. THIS SHOULD GENERATE STRONG WINDS BOTH AHEAD OF AND BEHIND
THE COLD FRONT ON TUE.

NO UPDATES PLANNED AT THIS TIME.

&&

.AVIATION...WINDS AT THE SLC TERMINAL WILL REMAIN OUT OF THE
SOUTH OVERNIGHT AND THROUGH THE MORNING. WINDS COULD BECOME GUSTY
AFTER ABOUT 12Z WITH A CHANCE THAT THIS COULD OCCUR AS EARLY AS
09Z. VFR CONDITIONS WILL PREVAIL.

&&

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

$$

WILENSKY

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000
FXUS65 KSLC 172209
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
409 PM MDT THU APR 17 2014

.SYNOPSIS...HIGH PRESSURE WILL SPREAD ACROSS THE REGION THROUGH
TONIGHT. THE NEXT WEAKENING STORM SYSTEM WILL CROSS THE REGION
LATE FRIDAY THROUGH SATURDAY. A STRONGER STORM WILL IMPACT THE
AREA MIDWEEK OF NEXT WEEK.

&&

.SHORT TERM (THROUGH 00Z MONDAY)...SHORT WAVE RIDGE IN PLACE WILL
FLATTEN AND SHIFT EAST TOMORROW AS A SPLITTING TROUGH MOVES INTO
THE WESTERN CONUS. THESE FEATURES SHOW UP WELL IN AFTERNOON
SATELLITE IMAGERY WITH THE NORTHERN SPLIT ENCROACHING ON THE
OREGON COAST AND THE SOUTHERN FALLING INTO A CLOSED CIRCULATION
OFF THE SOCAL COAST.

THE MORE PROGRESSIVE NORTHERN BRANCH OF THIS SPLIT WILL TRACK
THROUGH THE NORTHERN ROCKIES LATE TONIGHT THROUGH TOMORROW FORCING
A WEAK COLD FRONT TO MOVE INTO NORTHWESTERN UTAH BY DAWN. STRONG
WARM ADVECTION AHEAD OF THIS WILL CONTINUE INTO THE OVERNIGHT AND
ALLOW FOR WARMER LOW TEMPS TOMORROW MORNING. BREEZY SOUTHERLY
WINDS ACROSS THE WESTERN VALLEYS WILL REMAIN IN PLACE AS A THIS
FRONT ENCROACHES AS WELL WITH SHARPENING MSLP GRADIENT. MODELS
AGREE THIS FRONT WILL REACH AS FAR SOUTH AS ABOUT NEPHI TOMORROW
AFTERNOON BEFORE STALLING AS UPPER SUPPORT SHIFT EAST. MODEST LOW
LEVEL INSTABILITY IN WAKE OF ITS PASSAGE WILL PROVIDE CONVECTIVE
SUPPORT AND A FOCUS FOR SHALLOW DEVELOPMENT...ESPECIALLY TOMORROW
AFTERNOON INTO THE OVERNIGHT HOURS FOR AREAS ROUGHLY PROVO NORTH.
FINE TUNED FRONTAL ZONE IN GRIDS THIS SHIFT BUT NO MAJOR CHANGES.

MEANWHILE THE SOUTHERN BRANCH CIRCULATION WILL REMAIN CLOSED INTO
TOMORROW THEN OPEN AND LIFT NORTHEAST ADVECTING MOISTURE INTO THE
SOUTH SOUTHERN THIRD OF THE STATE TOMORROW AFTERNOON. SUBTLE CAPE
OVER THE HIGH TERRAIN WILL LIKELY YIELD ISOLATED STORMS OVER THE
MOUNTAINS TOMORROW AFTERNOON.

MODELS CONTINUE TO INDICATE A WEAK DEFORMATION FORMING OVER
CENTRAL UTAH FRIDAY NIGHT THROUGH SATURDAY AS THE SOUTHERN BRANCH
LIFTS INTO AND THROUGH THE 4-CORNERS. THIS AREA OF WEAK DYNAMIC
LIFT WILL GRADUALLY SHIFT OVER THE EAST...BUT CONVECTION STILL
APPEARS SCATTERED AT BEST AND GENERALLY QUITE SHALLOW. AS THE
TROUGH SHIFTS EAST SUNDAY DIURNAL INSTABILITY COMBINED WITH
REMNANT LOW LEVEL MOISTURE WILL KEEP A CHANCE OF CONVECTION OVER
GENERALLY FROM I-15 EAST AND INCREASED POPS A FAIR BIT FOR THE
AFTERNOON HOURS.

&&

.LONG TERM (AFTER 00Z MONDAY)...TEMPERATURES WILL RISE MONDAY AHEAD
OF A LARGE UPPER LOW THAT WILL BRING COOLER...WETTER WEATHER TO THE
FORECAST AREA MIDWEEK. STRONG SOUTHWESTERLY WINDS WILL DEVELOP
TUESDAY AHEAD OF THE COLD FRONT ASSOCIATED WITH THE LOW. THE GFS AND
EC SHOW 700MB WINDS IN THE 40 TO 50 KNOT RANGE ON TUESDAY
AFTERNOON...WITH SLIGHTLY STRONGER WINDS IN THE GFS. THE STRONG
UPPER LEVEL WINDS ALONG WITH A FAVORABLE SURFACE GRADIENT WILL
RESULT IN A VERY WINDY DAY TUESDAY ACROSS THE MAJORITY OF THE
FORECAST AREA. THE COLD FRONT WILL MOVE THROUGH THE CWA LATE TUESDAY
INTO WEDNESDAY. BOTH MODELS SHOW 700MB TEMPERATURES DROPPING TO -10C
ACROSS NORTHERN UTAH WEDNESDAY AFTERNOON IN PRECIP...WHICH WOULD BE
COLD ENOUGH FOR SNOW TO MIX DOWN TO THE VALLEY FLOORS.

THE EC IS MORE PROGRESSIVE WITH THE SYSTEM THAN THE GFS...MOVING THE
PRECIP OUT OF THE FORECAST AREA THURSDAY. THE GFS CLOSES THE UPPER
LOW OFF OVER NORTHERN UTAH...KEEPING THE PRECIP GOING ACROSS THE
HIGHER TERRAIN THURSDAY.

&&

.AVIATION...WINDS AT THE SLC TERMINAL WILL SHIFT TO THE NORTHWEST
AND BECOME LIGHT BETWEEN 23Z AND 00Z. HOWEVER...THERE IS A 20
PERCENT CHANCE THAT WINDS WILL REMAIN FROM THE SOUTH THROUGH THE
EVENING. VFR CONDITIONS WILL PREVAIL.


&&

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

$$

MERRILL/HOSENFELD


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000
FXUS65 KSLC 171643
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
1043 AM MDT THU APR 17 2014

.SYNOPSIS...HIGH PRESSURE WILL SPREAD ACROSS THE REGION THROUGH
TONIGHT. THE NEXT WEAKENING STORM SYSTEM WILL CROSS THE REGION
LATE FRIDAY THROUGH SATURDAY. A STRONGER STORM WILL IMPACT THE
AREA MIDWEEK OF NEXT WEEK.


&&

.DISCUSSION...HEIGHTS CONTINUE TO BUILD PER LATEST 500MB ANALYSIS
AS SHORT WAVE RIDGING TRANSITIONS OVERHEAD. MODELS INDICATE STRONG
WARM ADVECTION OVER THE NEXT 12 TO 18 HOURS AS SUCH...THIS AS FLOW
ALOFT BACKS TO THE SOUTHWEST AND INCREASES. 12Z KSLC RAOB
INDICATED A H7 TEMP OF -2 C BUT BY DAYS END EXPECTING THIS TO
CLIMB TO +5 C LOCALLY AND AROUND +8 C ACROSS THE SOUTH. BOTTOM
LINE FOR TODAY...CLEAR AND STABLE WITH AFTERNOON HIGHS SOME 10 OR
MORE DEGREES WARMER THAN YESTERDAY. NO SHORT TERM UPDATES MADE OR
PLANNED.

RIDGE TRANSITION AND OVERHEAD AMPLAFICATION IS A DIRECT RESULT OF
A SPLITTING TROUGH NOTED IN MORNING WATER VAPOR JUST OFF THE
PACIFIC COAST. THE MORE PROGRESSIVE NORTHERN BRANCH OF THIS SPLIT
WILL TRACK THROUGH THE NORTHERN ROCKIES LATE TONIGHT THROUGH
TOMORROW MORNING FORMING AND THEN SAGGING A WEAK COLD FRONT INTO
FAR NORTHERN UTAH THROUGH THAT TIME. DOWNSTREAM PROPAGATION OF
THE UPPER SUPPORT OF THIS WAVE WILL STALL THE FRONT OVER THE NORTH
FOR THE DAYTIME HOURS WHILST THE SOUTHERN BRANCH BEGINS TO CLOSE
OFF OVER SOCAL LIFTING NORTHEAST SPREADING MOISTURE INTO THE
SOUTH. SPC SHORT RANGE ENSEMBLES INDICATE THE BEST
INSTABILITY...ON THE ORDER OF 100-200 J/KG MUCAPE...WILL OCCUR
ALONG THE STALLED FRONTAL BOUNDARY OVER THE NORTH BUT SOME
POSITIVE VALUES EXIST OVER THE SOUTH AS WELL OWING TO SOME
CONVECTIVE POTENTIAL OVER THE HIGHER TERRAIN THERE. SHORT TERM
FORECAST PROBLEM OF THE DAY WILL BE TO FOCUS ON FINE TUNING
TOMORROWS FRONTAL LOCATION AND TIMING AS THIS WILL HAVE EFFECT ON
BOTH TEMPS AND FOCUS OF PRECIP.

MODELS CONTINUE TO INDICATE A WEAK DEFORMATION FORMING OVER
CENTRAL UTAH SATURDAY AS THE SOUTHERN BRANCH CLOSED FEATURE
BECOMES AN OPEN WAVE LIFTING NORTHEAST THROUGH THE 4-CORNERS.
EXPECT AREAL EXTENT OF PRECIP WILL BE GREATEST BENEATH THIS
DEFORMATION AS IT FORMS OVER CENTRAL UTAH THEN TRANSITIONS
EAST...BUT CONVECTION STILL APPEARS SCATTERED AT BEST AND
GENERALLY QUITE SHALLOW.

LONG RANGE WILL CONTINUE TO FOCUS ON A A MORE SIGNIFICANT STORM
THAT LOOKS TO BRING STRONG WINDS...MUCH COLDER TEMPERATURES AND
PRECIP TO THE REGION DURING THE MIDDLE OF NEXT WEEK.

&&

.AVIATION...SOUTHERLY WINDS WILL CONTINUE AT THE SLC TERMINAL
THROUGH THE MORNING AND INTO THE EARLY AFTERNOON. SURFACE WINDS
ARE EXPECTED TO SWITCH TO THE NORTHWEST BETWEEN 20-22Z IN THE 6 TO
9 KNOT RANGE...BUT A 30 PERCENT EXISTS THAT WINDS WILL REMAIN FROM
THE SOUTH THROUGH THE DAY.

&&

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

$$

MERRILL


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000
FXUS65 KSLC 170850
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
250 AM MDT THU APR 17 2014

.SYNOPSIS...HIGH PRESSURE WILL SPREAD ACROSS THE REGION TONIGHT
THROUGH TOMORROW. THE NEXT WEAKENING STORM SYSTEM WILL CROSS THE
REGION LATE FRIDAY THROUGH SATURDAY.

&&

.SHORT TERM (THROUGH 12Z SUNDAY)...
WATER VAPOR LOOP SHOWS A RIDGE ALONG THE WEST COAST WITH THE NEXT
STORM SYSTEM APPROACHING BRITISH COLUMBIA. AMDAR 400-250MB WIND
OBSERVATIONS REVEAL A 90-120KT ANTICYCLONICALLY CURVED JET FROM
BRITISH COLUMBIA INTO THE CENTRAL ROCKIES. GOES/GPS/RAP/00Z RAOB
INDICATE THE PRECIPITABLE WATER VALUE RANGES BETWEEN 0.12" AND
0.50".

NICE DAY ON TAP. WARM FRONT LIFTS THROUGH THE REGION FROM THE
SOUTHWEST THIS AFTERNOON. WINDS SHIFT TO THE SOUTH AND BEGIN TO
INCREASE...ALLOWING WARMER TEMPERATURES CONSIDERING 700MB
TEMPERATURES RISE TO ABOUT +4C.

COLD FRONT SLIPS INTO NORTHWEST UTAH LATE TONIGHT SO INTRODUCED LOW
END POPS TO THE NORTHWEST CORNER OF THE STATE. ITS NOTEWORTHY THAT
BY 12Z FRIDAY...SHORT RANGE ENSEMBLES INDICATE 50 J/KG MUCAPE WILL
BE LIKELY.

BEST CHANCE FOR SHOWERS FRIDAY WILL BE IN THE COOL SECTOR ACROSS
NORTHERN UTAH...THOUGH ENOUGH MOISTURE FROM AN ARIZONA CLOSED LOW
WILL ALLOW CONVECTION IN THE CENTRAL AND SOUTHERN MOUNTAINS DURING
THE AFTERNOON. COPIOUS CLOUDS DEVELOP AND THICKEN FRIDAY AND FRIDAY
NIGHT. LOWERED FORECAST HIGH FRIDAY DUE TO CLOUDS AND LIKELY PASSAGE
OF COLD FRONT ACROSS THE NORTH. INCREASED WINDS AHEAD OF THE COLD
FRONT GIVEN STRENGTHENING PRESSURE GRADIENT AND 30KT OF SOUTHWEST
FLOW AT 700MB.

FRONTAL BOUNDARY SETTLES INTO CENTRAL UTAH FRIDAY NIGHT...WITH
FURTHER MOISTURE ADVECTION OCCURRING ACROSS SOUTHEAST UTAH. BUMPED UP
POPS AHEAD OF SLOW-MOVING WEAKENING ARIZONA LOW THROUGH SATURDAY
MORNING.

WHILE THE REMNANT OF THE ARIZONA LOW CONTINUES TO WEAKEN AND LIFT
THROUGH SOUTHEAST UTAH SATURDAY AFTERNOON...RIDGING BEGINS TO BUILD
ACROSS WESTERN UTAH. WITH THINNING CLOUDS AND NOT A LOT OF
SUBSIDENCE YET...BELIEVE FAIRLY WIDESPREAD CONVECTION WILL DEVELOP
ESPECIALLY SOUTH OF INTERSTATE 80 DURING THE AFTERNOON AND EVENING
HOURS...GIVEN THE AMBIENT MOISTURE IN PLACE.

SPC THUNDER GUIDANCE FROM SHORT RANGE ENSEMBLES INDICATE POTENTIAL
BOTH FRIDAY AND SATURDAY AFTERNOONS.

&&

.LONG TERM (AFTER 12Z SUNDAY)...
MAJORITY OF THE MODEL GUIDANCE CONTINUES TO INDICATE AN ACTIVE
LONG TERM FORECAST PERIOD. A QUICK MOVING WAVE WILL MOVE ACROSS
THE NORTHERN ROCKIES SUNDAY INTO MONDAY. THE ASSOCIATED COLD FRONT
IS EXPECTED TO MOVE THROUGH THE STATE SUNDAY. A FEW SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE IN THE VICINITY OF THIS
FRONT...MAINLY ACROSS THE HIGHER TERRAIN.

A LARGE PACIFIC SYSTEM WILL APPROACH THE WEST COAST MONDAY. DEEP
SOUTHWESTERLY FLOW WILL DEVELOP AHEAD OF THIS SYSTEM ACROSS THE CWA
MONDAY BRINGING A VERY WARM DAY TO MUCH OF THE AREA. A FEW SHOWERS
OR THUNDERSTORMS WILL AGAIN BE POSSIBLE ACROSS THE HIGHER TERRAIN.

MODEL TO MODEL CONSISTENCY BEGINS TO DECREASE AS THE PACIFIC SYSTEM
BEGINS TO IMPACT THE WESTERN UNITED STATES EARLY NEXT WEEK. THE 00Z
GFS FEATURES A STRENGTHENING TROUGH THAT SWINGS THROUGH THE GREAT
BASIN WEDNESDAY INTO THURSDAY WHILE THE EC IS A WEAKER...MORE
PROGRESSIVE SYSTEM. CONTINUED THE TREND OF INCREASED POPS THROUGH
WEDNESDAY AND THURSDAY...THOUGH THE GFS SOLUTION WOULD WARRANT
HIGHER POPS.

THE BIGGEST TAKEAWAYS IN THE EXTENDED FORECAST ARE VERY WARM
TEMPERATURES...EXCEEDING NORMAL TEMPERATURES FOR LATE APRIL BY 10
TO 15 DEGREES SUNDAY THROUGH TUESDAY. A DRAMATIC COOL DOWN LOOKS
TO BE INCREASING IN CONFIDENCE REGARDLESS OF THE MODEL WEDNESDAY
INTO THURSDAY...WITH TEMPERATURES FALLING TO NEAR TO BELOW NORMAL
LEVELS AS AN AIRMASS REMINISCENT OF EARLY SPRING MOVES INTO THE
REGION. CONFIDENCE IS STILL FAIRLY LOW IN THE EVOLUTION AND
RESULTING PRECIPITATION IN ASSOCIATION WITH THE PACIFIC SYSTEM AT
THIS TIME.

&&

.AVIATION...SOUTHERLY WINDS WILL CONTINUE AT THE SLC TERMINAL
THROUGH THE MORNING AND INTO THE EARLY AFTERNOON. A SHIFT TO
NORTHWEST WINDS IS EXPECTED BETWEEN 20-22Z...THOUGH THERE IS A 30
PERCENT CHANCE WINDS WILL REMAIN SOUTHERLY THROUGHOUT THE DAY.

&&

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

$$

SHORT TERM...ROGOWSKI
LONG TERM/AVIATION...KRUSE

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000
FXUS65 KSLC 170359
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
959 PM MDT WED APR 16 2014

.SYNOPSIS...HIGH PRESSURE WILL SPREAD ACROSS THE REGION TONIGHT
THROUGH TOMORROW. THE NEXT WEAKENING STORM SYSTEM WILL CROSS THE
REGION LATE FRIDAY THROUGH SATURDAY.

&&

.DISCUSSION...THE UPSTREAM RIDGE AXIS IS ALONG THE WEST COAST THIS
EVE AND WILL BE SHIFTING INTO THE GREAT BASIN LATER TONIGHT THEN
ACROSS UT TOMORROW. SUBSIDENCE AHEAD OF THIS RIDGE HAS CLEARED
SKIES ACROSS THE CWA AND EXPECT ONLY DISSIPATING CIRRUS STREAMING
THRU THE RIDGE OVER THE CWA THE REST OF THE NIGHT. THE CHILLY
AIRMASS IN PLACE AND MOSTLY CLEAR SKIES WILL ALLOW TEMPS TO DIP
TO COOL READINGS OVERNIGHT.

STRONG AIRMASS WARMING WILL ACCOMPANY THE ADVANCING RIDGE AND
HIGHS TOMORROW SHOULD WARM 10-15 DEGREES FROM TODAY UNDER MOSTLY
SUNNY SKIES AND LOCAL SOUTH WINDS BY AFTERNOON.

THE NEXT TROF IS STILL FORECAST TO SPLIT AS IT MOVES INLAND WITH
THE SRN CLOSED LOW NOW FORMING SOUTHWEST OF SAN DIEGO CA BY FRI
MORNING. THIS FEATURE DOES LIFT INTO NRN AZ BY SAT MORNING AND
PUSHES A WEAK FRONT UP FROM THE SOUTH INTO SRN UT FRI NIGHT.

THE NRN BRANCH SENDS A WEAK COLD FRONT INTO NRN UT ON FRI WITH
INCREASING INSTABILITY ACROSS THE CWA IN BETWEEN THESE FEATURES ON
FRI. THE BEST CHANCE FOR PRECIP APPEARS TO BE FRI NIGHT WITH
INSTABILITY AND MOISTURE KEEPING SOME CONVECTION LINGERING SAT BUT
TEMPS WARMING BACK UP.

RIDGING BRINGS ADDITIONAL WARMING AND DRYING FOR SUN AND THE NEXT
FAIRLY LARGE DEEP PAC TROF SETS UP A SWLY FLOW ON MON THAT
INCREASES AND COULD BECOME FAIRLY STRONG TUE AS THIS TROF EDGES
INLAND.

UPDATED FORECASTS TO REDUCE SKY COVER ACROSS THE CWA AND REMOVE
EVE POPS FROM THE SRN MTNS. BUMPED WINDS UP A BIT IN DIXIE AS A
NELY GRADIENT SHOULD KEEP IT LOCALLY BREEZY MOST OF THE REST OF
THE NIGHT. NO ADDITIONAL UPDATES PLANNED.

&&

.AVIATION...WINDS AT THE SLC TERMINAL WILL BECOME SOUTHERLY BY 05Z
AND REMAIN SOUTHERLY INTO THURSDAY AFTERNOON. VFR CONDITIONS WILL
PREVAIL UNDER MOSTLY CLEAR SKIES.

&&

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

$$

WILENSKY

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000
FXUS65 KSLC 162152
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
352 PM MDT WED APR 16 2014

.SYNOPSIS...HIGH PRESSURE WILL SPREAD ACROSS THE REGION TONIGHT
THROUGH TOMORROW. THE NEXT WEAKENING STORM SYSTEM WILL CROSS THE
REGION LATE FRIDAY THROUGH SATURDAY.


&&

.SHORT RANGE (THROUGH 00Z SUNDAY)...SKIES ARE CLEARING WEST TO
EAST THIS AFTERNOON AS A WEAK MID LEVEL WAVE EXITS THE AREA. THIS
WAVE MOVED THROUGH QUITE A STABLE ENVIRONMENT AND PRODUCED LITTLE
IN THE WAY OF PRECIP...BUT A FEW BUILDUPS DID POP AND STILL REMAIN
OVER THE HIGHEST TERRAIN OF THE SOUTH. EXPECT THESE TO DISSIPATE
JUST PRIOR TO SUNSET TONIGHT BUT LEFT MENTION OF SLIGHT CHANCE
POPS THERE FOR THE TIME BEING.

500MB ANALYSIS INDICATES INCREASED HEIGHTS BUILDING IN FROM THE
WEST IN WAKE OF THIS WAVE ATTM. AXIS OF MID LEVEL RIDGE CURRENTLY
ORIENTED ALONG THE WEST COAST WILL SHIFT OVERHEAD TOMORROW
ALLOWING H7 TEMPS TO WARM SOME 4 TO 6 DEGREES C OVER THE NEXT 24
HOURS...RESULTING IN ROUGHLY 5 TO 10 F DEGREES OF SURFACE WARMING
VS THOSE TEMPS REALIZED THIS AFTERNOON.

TROUGH NOTED NEAR 145W IN WATER VAPOR WILL SPLIT HARD AS IT
INTERACTS AND DISPLACES THE RIDGE EAST FRIDAY. SHOULD SEE FURTHER
AND QUITE RAPID WARMING BEGINNING FRIDAY MORNING AS A WEAK COLD
FRONT ASSOCIATED WITH THE NORTHERN SPLIT BEGINS TO TRACK INTO THE
NORTHWEST. BREEZY SOUTHERLY WINDS APPEAR LIKELY ACROSS THE WESTERN
VALLEYS AND MOUNTAINS AS GRADIENT TIGHTENS IN FRONT OF THIS
BOUNDARY. ANTICIPATE FOCUS OF PRECIP WILL BE COINCIDENT WITH THE
H7 BAROCLINIC ZONE OF THIS FEATURE AS IT SAGS SOUTHEAST THEN
STALLS AND WASHES OUT LATE FRIDAY INTO SATURDAY MORNING. GLOBAL
MODELS INDICATE THE SOUTHERN BRANCH WILL CLOSE OFF OVER SOCAL THEN
LIFT NORTHEAST THROUGH THE 4 CORNERS AREA AS AN OPEN WAVE FRIDAY
NIGHT THROUGH SATURDAY. SHOULD SEE A MID LEVEL DEFORMATION DEVELOP
BETWEEN THESE FEATURES PROVIDING FOCUSED PRECIP CHANCES ACROSS
NORTHERN THEN CENTRAL THEN EASTERN UTAH THROUGH THAT TIME. WILL
LIKELY NEED TO ADJUST PLACEMENT AND TIMING OF THIS ZONE AS FINE
DETAILS BECOME MORE UNIFORM.

&&

.LONG TERM (AFTER 00Z SUNDAY)...HEIGHTS WILL SLOWLY RISE SUNDAY INTO
MONDAY AS THE WEEKEND SYSTEM MOVES EAST. SOUTHWESTERLY FLOW WILL
DEVELOP MONDAY AHEAD OF A LARGE UPPER LOW THAT BOTH THE GFS AND EC
SUGGEST WILL IMPACT MUCH OF THE WESTERN US MIDWEEK NEXT WEEK. WHILE
BOTH MODELS AGREE THAT THIS UPPER LOW WILL IMPACT THE AREA...THERE
ARE DIFFERENCES IN THE DETAILS BETWEEN THE MODELS. THE GFS CLOSES
THE LOW OFF AS IT MOVES ONSHORE...WHILE THE EC MAINTAINS MORE OF AN
OPEN WAVE. THE EC IS SLIGHTLY FASTER WITH THE ASSOCIATED COLD
FRONT...MOVING IT INTO THE STATE TUESDAY AFTERNOON...WHILE THE GFS
SHOWS THE COLD FRONT MOVING INTO THE STATE TUESDAY NIGHT/WEDNESDAY
MORNING. ALSO...THE EC IS QUITE A BIT COLDER...WITH 700MB TEMPS AS
LOW AS -11C ACROSS NORTHERN UTAH ON WEDNESDAY. IN BOTH MODELS...THE
COLD FRONT IS VERY STRONG...WHICH WOULD RESULT IN A VERY WINDY DAY
ON TUESDAY FOR THE FORECAST AREA.

AS FAR AS THE GRIDS...INCREASED POPS FOR THE MIDWEEK TIME PERIOD.
THOUGH THERE ARE DIFFERENCES AS FAR AS TIMING AND STRENGTH OF THE
SYSTEM NEXT WEEK...BOTH MODELS SUGGEST THAT COOL...UNSETTLED WEATHER
CAN BE EXPECTED MIDWEEK NEXT WEEK.

&&

.AVIATION...WINDS AT THE SLC TERMINAL WILL REMAIN FROM THE NORTHWEST
THROUGH 03Z TO 05Z...AND THEN SWITCH TO THE SOUTHEAST DRAINAGE. VFR
CONDITIONS WILL PREVAIL.

&&

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

$$

MERRILL/HOSENFELD


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000
FXUS65 KSLC 161544
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
944 AM MDT WED APR 16 2014

.SYNOPSIS...A WEAK WEATHER SYSTEM WILL MOVE SOUTHEAST ACROSS THE
REGION TODAY...FOLLOWED BY HIGH PRESSURE FOR THURSDAY. THE NEXT
WEAKENING STORM SYSTEM WILL CROSS THE REGION FRIDAY THROUGH
SATURDAY.

&&

.DISCUSSION...THE SURFACE COLD FRONT THAT MOVED THROUGH THE AREA
OVERNIGHT HAS NOW PUSHED INTO THE FOUR CORNERS REGION LEAVING
NORTHWEST FLOW IN ITS WAKE. GUSTY POST FRONTAL WINDS OVER THE
HIGHER TERRAIN OF THE SOUTH HAS SHOWN SIGNS OF DECREASING AND
THESE TRENDS ARE EXPECTED TO CONTINUE THROUGH THE DAY. MID AND
HIGH LEVEL CLOUDS CONTINUE TO INCREASE FROM WEST TO EAST
ASSOCIATED WITH A WEAK TRAILING WAVE OVER EASTERN NEVADA THIS
MORNING...AND HAVE INCREASED CLOUD COVERAGE AS THE ONLY NOTABLE
UPDATE TO THE FORECAST. ALTHOUGH A FEW SHOWERS REMAIN POSSIBLE
OVER THE HIGHER TERRAIN TODAY...PASSAGE OF THIS WEAK SYSTEM WILL
BRING MINIMAL CHANGES TO SENSIBLE WEATHER.

MID LEVEL RIDGING OVER THE EASTERN PACIFIC WILL SHIFT INLAND
TONIGHT THROUGH TOMORROW ALLOWING H7 TEMPS TO WARM SOME 4 TO 6
DEGREES C OVER THE NEXT 24 HOURS. EXPECTING SOME 10 DEGREES F
WARMING AT THE SURFACE FOR THURSDAY WITH ANY LINGERING CLOUD COVER
THINNING DURING THE AFTERNOON HOURS.

THE PRIMARY FORECAST CHALLENGE FOR THE DAY WILL FOCUS ON THE
TROUGH CURRENTLY ORIENTED AROUND 150W. NOT EXPECTING SIGNIFICANT
IMPACT TO THE FORECAST AREA AS THIS TROUGH SPLITS AND MOVES ON
SHORE DURING THE FRIDAY/SATURDAY PERIOD...BUT SOME SHOWER ACTIVITY
DOES LOOK TO DEVELOP AREAWIDE AS THE SOUTHERN SPLIT TRACKS THROUGH
THE DESERT SOUTHWEST AND THE NORTHERN DRAGS THEN STALLS A WEAK
FRONTAL BOUNDARY ACROSS THE NORTH.

LONG TERM WILL BE FOCUSING ON THE POTENTIAL OF A MUCH STRONGER
TROUGH FOR EARLY NEXT WEEK...BUT AS NOTED IN THE LAST PACKAGE
INCONSISTENCIES IN STRENGTH AND EVOLUTION OF THIS SYSTEM REMAIN
AND WILL LIKELY CONTINUE FOR SEVERAL RUNS.

&&

.AVIATION...WINDS AT THE SLC TERMINAL WILL REMAIN FROM THE NORTH
THROUGH THE DAY. WIND SPEED WILL INCREASE INTO THIS AFTERNOON...WITH
SPEEDS ABOVE 7 KNOTS BY 16Z TO 17Z. VFR CONDITIONS WILL PREVAIL.

&&

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

$$

MERRILL/HOSENFELD


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