Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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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

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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