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000
FXUS65 KSLC 200932
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
332 AM MDT SUN APR 20 2014

.SYNOPSIS...A WEAK STORM SYSTEM WILL MOVE SLOWLY OUT OF THE
REGION LATE TODAY. A WARM SOUTHWEST FLOW WILL DEVELOP MONDAY. A
COLD SPRING STORM WILL IMPACT THE AREA TUESDAY AND WEDNESDAY.

&&

.SHORT TERM (THROUGH 12Z WEDNESDAY)...
WATER VAPOR LOOP SHOWS A DISTURBANCE EXITING THE FOUR CORNERS
REGION AS ANOTHER CROSSES THE FAR NORTHERN ROCKIES. AMDAR
400-250MB WIND OBSERVATIONS REVEAL A 90-110KT WESTERLY JET OVER
THE PACIFIC NORTHWEST. GOES/GPS/RAP/00Z RAOB INDICATE THE
PRECIPITABLE WATER VALUE RANGES BETWEEN 0.15" AND 0.70".

700-850MB RAP SATURATED EQUIVALENT POTENTIAL TEMPERATURE AND
STREAMLINES INDICATE A COOL FRONT WILL BE THROUGH NORTHERN UTAH BY
12Z...BUT WEAKEN AS IT MAKES ITS WAY INTO SOUTHERN UTAH THIS
AFTERNOON. SHORT RANGE ENSEMBLE GUIDANCE SUGGESTS PLENTY OF
INSTABILITY AHEAD OF THE BOUNDARY DUE TO THE SAMPLED PRECIPITABLE
WATER VALUES ALLUDED TO EARLIER. KEPT MENTION OF ISOLATED TO
SCATTERED CONVECTION ALONG AND AHEAD OF THE BOUNDARY THROUGH THE
AFTERNOON HOURS...DECAYING QUICKLY AROUND SUNSET. DOWNSLOPE WINDS
WILL LIKELY BE SOMEWHAT ENHANCED THIS AFTERNOON AND EVENING 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 HAS TRENDED MORE
SUPPORTIVE OF CONVECTION MAINLY IN THE HIGHER TERRAIN AS THE WARM
FRONT LIFTS THROUGH THE AREA.

WARM SOUTH WINDS DEVELOP MONDAY AFTERNOON AND INCREASE MONDAY NIGHT.
COULD SEE OUR FIRST 80 DEGREE DAY AT SLC MONDAY. CONTINUED TO TREND
TEMPERATURES FURTHER ABOVE GUIDANCE MONDAY NIGHT AHEAD OF A SHARP
COLD FRONT OWING TO GUSTY SOUTH WINDS AND CLOUD COVER.

STRONG PRESSURE GRADIENT...PRESSURE FALLS TO THE NORTH...AND 40-
55KTS OF 700MB FLOW ALL SUPPORTIVE OF A HIGH WIND EVENT TUESDAY.
GUIDANCE IS A BIT FASTER WITH THE COLD FRONT CRASHING THROUGH
NORTHERN UTAH TUESDAY AFTERNOON...WITH TIMING STILL FAIRLY UNCERTAIN
AT THIS POINT. NEVERTHELESS...TIGHT THERMAL GRADIENT CONTINUES TO
STRONGLY SUPPORT A HIGH WIND EVENT POST FRONTAL AS WELL...ESPECIALLY
CONSIDERING THE TIME OF DAY.

MUCH COLDER TUESDAY NIGHT WITH INSTABILITY AND OROGRAPHIC SHOWERS
FORECAST FOR THE NORTH. BUMPED POPS HIGHER ESPECIALLY NORTH OF
INTERSTATE 80. SNOW LEVELS FALL BELOW 5000 FEET TUESDAY NIGHT WITH
SNOW ACCUMULATIONS EXPECTED FOR THE NORTHERN MOUNTAINS AND BENCHES.

HAVE ISSUED A SPECIAL WEATHER STATEMENT ADDRESSING THE HIGHLIGHTS
FOR THE UPCOMING STORM. NEXT SHIFT MAY NEED TO PONDER A HIGH WIND
WATCH FOR MANY OF THE WESTERN ZONES TUESDAY.

&&

.LONG TERM (AFTER 12Z WEDNESDAY)...
BY WEDNESDAY MORNING...THE TROUGH IS CENTERED OVER THE AREA WITH
THE ASSOCIATED COLD FRONT DOWN INTO CENTRAL/SOUTHERN UTAH. TIGHT
PRESSURE GRADIENT CONTINUES TO WEAKEN DURING THE DAYTIME
HOURS...ALLOWING GUSTY WINDS TO WANE. THE GFS KEEPS LINGERING
MOISTURE AND INSTABILITY OVER NORTHERN AND CENTRAL UTAH THROUGH
THURSDAY MORNING DUE TO ITS FARTHER SOUTH TRACK OF THE TROUGH.
WITH ITS FARTHER SOUTH SOLUTION...THE LATEST ECMWF IS ALREADY
BRINGING DRIER AIR INTO MUCH OF THE CWA BY WEDNESDAY EVENING. HAVE
MORE CLOSELY FOLLOWED THE GFS SOLUTION DURING THIS PERIOD AS IT
HAS BEEN THE MORE CONSISTENT OF THE TWO MODELS.

HIGH PRESSURE IS EXPECTED TO RETURN THURSDAY AS THE TROUGH
EXITS...REMAINING IN PLACE THROUGH FRIDAY MORNING. THIS WILL ALLOW
FOR A QUICK WARMING TREND OVER THE CWA. THE EC WARMS THINGS A BIT
MORE QUICKLY THAN THE GFS...PARTICULARLY OVER THE SOUTH...DUE TO
STRONG RIDGING.

GLOBAL MODELS CONTINUE TO INDICATE ANOTHER PACIFIC STORM SYSTEM
MOVING OVER THE AREA FOR THE WEEKEND. LATEST EC IS A BIT FASTER WITH
THE SYSTEM...BRINGING IT THROUGH IN PIECES FRIDAY NIGHT THROUGH
MONDAY. THE SYSTEM APPEARS TO BE SIGNIFICANTLY BETTER ORGANIZED IN
THE GFS BUT IT REALLY DOES NOT BEGIN TO IMPACT THE AREA UNTIL
SATURDAY AFTERNOON/EVENING AND EXITS BY MONDAY MORNING.
REGARDLESS...ALL MODELS ARE INDICATING MOIST AND UNSETTLED WEATHER
DURING THIS PERIOD AND HAVE MOVED POPS ABOVE CLIMO IN THE
EXTENDED.

&&

.AVIATION...THE SLC TERMINAL WILL SEE VFR CONDITIONS THROUGHOUT THE
DAY WITH SOME SCATTERED CLOUDS. SOUTHEAST WINDS ARE EXPECTED TO
SHIFT TO THE NORTHWEST A BIT EARLIER THAN USUAL WITH THE PASSAGE OF
A WEAK FRONT...SOMETIME BETWEEN 15Z AND 17Z.

&&

&&

.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 200204
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
804 PM MDT SAT APR 19 2014

.SYNOPSIS...A WEAK STORM SYSTEM WILL MOVE SLOWLY OUT OF THE
REGION TONIGHT THROUGH SUNDAY. A WARM SOUTHWEST FLOW WILL DEVELOP
MONDAY. A COLD SPRING STORM WILL IMPACT THE AREA TUESDAY AND
WEDNESDAY.

&&

.DISCUSSION...INSTABILITY SHOWERS UNDER THE DEFORMATION ZONE
ACROSS THE CWA NORTH OF THE WEAK CLOSED LOW TRACKING ACROSS AZ ARE
STARTING TO DIE OFF THIS EVE. THESE HAVE ENDED ACROSS MUCH OF THE
NORTH EXCEPT ALONG THE NV BORDER BUT PERSIST ACROSS THE SOUTH.

EXPECT THE DECREASING TREND IN COVERAGE TO CONTINUE THROUGH THE
REST OF THE EVE WITH ONLY A FEW STRAGGLERS LASTING PAST MIDNIGHT.

EXPECT SUFFICIENT INSTABILITY TO KEEP ISOLATED TO SCATTERED
CONVECTION GOING AGAIN TOMORROW MAINLY OVER SRN AND ERN UT WHILE
THE NORTH STAYS DRY IN THE WAKE OF A WEAK DRY FRONT THAT SAGS
ACROSS NRN UT. EXPECTED TEMPS TO REMAIN MILD EVEN NORTH OF THE
FRONT.

AN UPPER RIDGE BUILDS INTO THE GREAT BASIN SUN NIGHT AND THE AXIS
QUICKLY CROSSES UT BY MON AFTN WITH A VERY MILD SWLY FLOW
DEVELOPING. MODELS HAVE BEEN INSISTING THAT ISOLATED CONVECTION
WILL DEVELOP ACROSS ABOUT THE NRN 1/2 OF THE CWA MON AFTN/EVE AS
THE LAST OF THE SOMEWHAT MOIST AND UNSTABLE AIRMASS FROM THIS
WEEKEND LIFTS ACROSS THE N IN THE INCREASINGLY DIFFLUENT SWLY
FLOW. DONT SEE MUCH THREAT OF PRECIP FROM THIS BUT ISOLATED GUSTY
WINDS ARE POSSIBLE.

THE SURFACE GRADIENT TIGHTENS CONSIDERABLY MON NIGHT THRU MIDDAY
TUE ALONG WITH STRENGTHENING SWLY FLOW ALOFT AHEAD OF A FAIRLY
DEEP COLD PAC TROF AND STRONG SOUTH WINDS SHOULD DEVELOP ACROSS
MUCH OF THE CWA IN RESPONSE. THIS TROF SWINGS INLAND TUE AND SENDS
A STRONG COLD FRONT THRU NRN UT AHEAD OF IT LATE TUE AFTN THRU TUE
EVE IF LATEST GFS TIMING IS CORRECT...AND IT HAS BEEN FAIRLY
CONSISTENT FOR THE LAST SEVERAL RUNS.

THE COMBINATION OF A TIGHT THERMAL GRADIENT AND FAVORABLE TIME OF
DAY SHOULD RESULT IN VERY STRONG POST FRONTAL WINDS FOR SEVERAL
HOURS AFTER THE FRONT PASSES...IMPACTING THE SALT FLATS AND MUCH
OF THE WASATCH FRONT. WINDS SHOULD THEN DROP OFF AS PRECIP
DEVELOPS BY LATE EVE. THE AIRMASS WITH THIS TROF IS FORECAST TO BE
COLD ENOUGH TO SEND SNOW TO THE VALLEY FLOORS BUT DONT EXPECT MUCH
IF ANY ACCUMULATION BELOW ABOUT 5000 FT.

COLD INSTABILITY SNOW SHOWERS LINGER ACROSS THE NORTH THRU WED
NIGHT.

ABOUT ALL THAT IS EXPECTED FOR THE SOUTH FROM THIS EVENT WOULD BE
STRONG WINDS AND COOLER TEMPS.

UPDATED FORECASTS EARLIER TO LOWER POPS MOST AREAS THIS EVE AND
MADE SOME ADJUSTMENTS TO SKY COVER. NO ADDITIONAL UPDATES PLANNED.

&&

.AVIATION...VFR CONDITIONS ARE EXPECTED AT THE SLC TERMINAL
THROUGHOUT THE NIGHT WITH ANY CIGS REMAINING ABV 7000 FT.
WINDS ARE EXPECTED TO SHIFT TO THE SOUTHEAST BETWEEN 03Z AND 04Z.

&&

.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 192224
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
424 PM MDT SAT APR 19 2014

.SYNOPSIS...A WEAK STORM SYSTEM WILL MOVE SLOWLY ACROSS THE
REGION THROUGH THE WEEKEND. A SIGNIFICANT WARMING TREND IS THEN
EXPECTED FOR THE EARLY PORTION OF THE WEEK AHEAD OF A STRONGER
STORM WHICH WILL IMPACT THE AREA BY MIDWEEK.

&&

.SHORT TERM (THROUGH 12Z TUESDAY)... UPPER LOW DRIFTING SLOW
ACROSS ARIZONA THIS AFTERNOON. TO THE NORTH OF THIS FEATURE A MID-
LEVEL DEFORMATION AXIS STRETCHES FROM SOUTHWEST UTAH THROUGH SOUTH
CENTRAL WYOMING. BENEATH THIS FEATURE NUMEROUS SHOWERS...AND
ISOLATED THUNDERSTORMS...HAVE DEVELOPED OVER UTAH/S CENTRAL AND
SOUTHERN MOUNTAINS. IN ADDITION...SHOWERS AND ISOLATED
THUNDERSTORMS HAVE DEVELOPED OVER EASTERN NEVADA AND WILL CONTINUE
TO MOVE INTO WEST CENTRAL AND SOUTHWEST UTAH THIS EVENING. TO THIS
POINT COVERAGE OVER MOST VALLEY LOCATIONS REMAINS ISOLATED.
ANTICIPATE THAT THIS ACTIVITY WILL CONTINUE THROUGH THE EVENING
BEFORE DIMINISHING AFTER SUNSET.

SUNDAY...AS UPPER LOW EXITS THE DESERT SOUTHWEST A LIFTING WAVE IN
THE NORTHERN INTERMOUNTAIN REGION NUDGES A COLD FRONT INTO UTAH
DURING THE DAY. THIS BRING A LITTLE COOLER MID LEVEL AIR INTO THE
STATE AND EXPECT HIGH TEMPERATURES TO BE A COUPLE DEGREES COOLER
THAN TODAY/S ACROSS MUCH OF CENTRAL AND NORTHERN UTAH. FRONT IS A
DECAYING FEATURE WITH LITTLE DYNAMIC SUPPORT. STILL DECENT MOISTURE
IN PLACE...AND MODELS AGAIN SHOW WEAK INSTABILITY...SO WILL KEEP
MENTION OF SCATTERED MOUNTAIN SHOWERS IN THE UINTAS AND CENTRAL
AND SOUTHERN MOUNTAINS WITH ISOLATED POPS FOR SOUTHERN AND EASTERN
VALLEYS.

SUNDAY NIGHT THROUGH MONDAY NIGHT...MID LEVEL FLOW BEGINS TO BACK
SHARPLY ON SUNDAY NIGHT AS VIGOROUS TROUGH APPROACHES THE WEST
COAST. STRONG WARM ADVECTION CONTINUES THROUGH THE DAY ON MONDAY
WITH 700 MB TEMPERATURES APPROACHING +8C BY 00Z TUESDAY. SO A
VERY WARM DAY IN STORE ON MONDAY AND SLC MAY HIT 80 FOR THE FIRST
TIME THIS YEAR. MONDAY NIGHT WILL ALSO BE QUITE MILD AS SOUTHERLY
FLOW DEVELOPS AND STRONG SOUTHERLY SURFACE GRADIENT KEEPS WINDS
GOING THROUGH THE NIGHT.

.LONG TERM (AFTER 12Z TUESDAY)...SOUTHWEST FLOW OVER THE FORECAST
AREA IS EXPECTED TO INCREASE SUBSTANTIALLY DURING THE DAY TUESDAY
AND CONTINUE INTO THE EVENING. THIS IS A RESULT OF THE NEXT PACIFIC
STORM SYSTEM APPROACHING FROM THE WEST. GFS AND ECMWF BOTH INDICATE
A 700 MB FLOW IN EXCESS OF 50 KTS JUST AHEAD OF THE FRONTAL BOUNDARY
WHICH IS EXPECTED TO PUSH INTO NORTHWEST UTAH TUESDAY AFTERNOON AND
THROUGH THE WASATCH FRONT TUESDAY EVENING. THESE CONDITIONS WILL BE
QUITE FAVORABLE FOR A HIGH WIND EVENT OVER MUCH OF THE STATE
TUESDAY. BEHIND THE FRONT...WINDS WILL DROP OFF TO BELOW ADVISORY
CRITERIA. A DRAMATIC COOLDOWN IS ALSO EXPECTED BEHIND THE COLD
FRONT. MODELS SUGGEST A -15 TO -20 DEGREE DROP IN 700 MB
TEMPERATURES FROM TUESDAY TO WEDNESDAY. REASONABLE DYNAMICS OVER
NORTHERN AND CENTRAL UTAH ALONG AND BEHIND THE FRONT COMBINED WITH
RELATIVELY GOOD MOISTURE WILL ALLOW GOOD...BUT NOT GREAT
PRECIPITATION AMOUNTS. SNOW IS LIKELY IN THE MOUNTAINS AND COULD
REACH DOWN TO THE VALLEY FLOORS WEDNESDAY MORNING...ALTHOUGH
AMOUNTS WILL BE LOW AND SHORT LIVED.

BY WEDNESDAY NIGHT...THE TROUGH IS EXPECTED TO EXIT THE AREA IF YOU
BELIEVE THE ECMWF WHILE THE GFS SOLUTION IS CONSIDERABLY SLOWER.
EITHER WAY A RIDGE WILL FOLLOW FOR FRIDAY AND SHIFT EAST SATURDAY.
MODELS THEN SUGGEST NEXT SYSTEM FOR LATTER HALF OF THE WEEKEND...BUT
STILL TOO EARLY TO DISCUSS TIMING AND STRENGTH OF SYSTEM.

&&

.AVIATION...VFR CONDITIONS ARE EXPECTED AT THE SLC TERMINAL
THROUGHOUT THE DAY WITH MOSTLY CLOUDY SKIES. LIGHT NORTHWEST WINDS
ARE EXPECTED TO SHIFT TO THE SOUTHEAST BETWEEN 03Z AND 04Z. THERE IS
A 20 PERCENT CHANCE THAT SHOWERS IN THE VICINITY OF THE TERMINAL
WILL RESULT IN PERIODS OF GUSTY AND/OR ERRATIC WINDS THIS AFTERNOON.

&&

&&

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

$$

PUBLIC...GRAHAM
AVIATION...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 191717
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
1117 AM MDT SAT APR 19 2014

.SYNOPSIS...A WEAK STORM SYSTEM WILL MOVE SLOWLY ACROSS THE
REGION THROUGH THE WEEKEND. A SIGNIFICANT WARMING TREND IS THEN
EXPECTED FOR THE EARLY PORTION OF THE WEEK AHEAD OF A STRONGER
STORM WHICH WILL IMPACT THE AREA BY MIDWEEK.


&&

.DISCUSSION...UPPER LEVEL LOW MOVING SLOWLY ACROSS WESTERN ARIZONA THIS
MORNING. WITH CLOSED LOW TO THE SOUTH...MID LEVEL DEFORMATION
ZONE STRETCHES FROM SOUTHWEST UTAH TO SOUTHWEST WYOMING. THIS
DEFORMATION AXIS WILL DRIFT EAST THROUGH THE DAY. RELATIVELY MOIST
AIRMASS IN PLACE WITH PRECIPITABLE WATER VALUES ACROSS THE STATE
IN EXCESS OF .50". NAM AND GFS BOTH INDICATE WEAK SURFACE-BASED
CAPE THIS AFTERNOON. WITH FORCING ASSOCIATED WITH DEFORMATION ZONE
AND MOIST AIRMASS IN PLACE...ANTICIPATE SCATTERED VALLEY SHOWERS
AND NUMEROUS MOUNTAIN SHOWERS THIS AFTERNOON ALONG AND EAST OF THE
DEFORMATION AXIS. ADDITIONALLY...EXPECT SHOWERS AND ISOLATED
STORMS TO DEVELOP OVER THE HIGHER TERRAIN IN EASTERN NEVADA AND
DRIFT INTO THE WEST CENTRAL AND SOUTHWEST PORTIONS OF THE STATE
THIS AFTERNOON AND EVENING.

WITH THIS UPDATE...LOWERED VALLEY POPS IN EAST CENTRAL UTAH AND
THE UINTA BASIN AS IT APPEARS THAT CONVECTION WILL BE SCATTERED IN
COVERAGE OVER VALLEY LOCATIONS. ALSO...TRIMMED POPS A BIT IN
NORTHWEST UTAH GIVEN ITS LOCATION IN LARGER SCALE REGION OF
SUBSIDENCE NORTHWEST OF THE DEFORMATION AXIS. ALSO LOWERED
AFTERNOON MAX TEMPERATURES A BUT IN EASTERN ZONES GIVEN THE
EXTENSIVE CLOUD COVER OVER THAT AREA.

&&

.AVIATION...VFR CONDITIONS ARE EXPECTED AT THE SLC TERMINAL
THROUGHOUT THE DAY WITH MOSTLY CLOUDY SKIES. LIGHT NORTHWEST WINDS
ARE EXPECTED TO SHIFT TO THE SOUTHEAST BETWEEN 03Z AND 04Z. THERE IS
A 20 PERCENT CHANCE THAT SHOWERS IN THE VICINITY OF THE TERMINAL
WILL RESULT IN PERIODS OF GUSTY AND/OR ERRATIC WINDS THIS AFTERNOON.

&&

&&

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

$$

PUBLIC...GRAHAM
AVIATION...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 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

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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)




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