Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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FXUS65 KSLC 052216
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
416 PM MDT THU MAY 5 2016

.SYNOPSIS...THE UPPER LEVEL LOW PRESSURE SYSTEM OFF THE SOUTHERN
CALIFORNIA COAST MOVE SLOWLY EAST INTO THE GREAT BASIN FOR THE
UPCOMING WEEKEND. A SECOND COLDER STORM SYSTEM WILL MOVE SOUTH
FROM WESTERN CANADA AND MOVE THROUGH THE REGION EARLY NEXT WEEK.

&&

.SHORT TERM (UNTIL 06Z MONDAY)...THE COLD CORE UPPER LOW CURRENTLY
OFF THE SOUTHERN CALIFORNIA COAST WILL MOVE INLAND ON FRIDAY. FROM
THERE THIS FEATURE WILL MOVE EAST AND EXPAND ACROSS MUCH OF THE
GREAT BASIN AND DESERT SOUTHWEST FOR THE UPCOMING WEEKEND.

THE WARM SOUTHERLY FLOW ALOFT AHEAD OF THE LOW HAS MAINTAINED MUCH
ABOVE NORMAL TEMPS EVEN WITH THE CLOUD COVER. BEGINNING TO SEE
WEAK CONVECTION FIRE UP ACROSS EXTREME SOUTHWEST AND SOUTHEAST
UTAH. OVER THE SOUTHWEST THIS RATHER WEAK CONVECTION MAY BE TIED
TO A VORTICITY EJECTING OUT AHEAD OF THE MAIN UPPER LOW THROUGH
SOUTHERN NEVADA/WESTERN ARIZONA. THIS FEATURE IS WORKING WITH
QUITE LIMITED MOISTURE AND WILL AT BEST GENERATE A FEW VERY LIGHT
SHOWERS...OR ON THE OFF CHANCE A DRY THUNDERSTORM.

OVER THE SOUTHEAST A SMALL MOISTURE TAP EXTENDING BACK INTO
SOUTHWEST NEW MEXICO IS SPAWNING A MORE EXTENSIVE AREA OF
CUMULUS...WITH SUFFICIENT INSTABILITY TO SUPPORT A FEW HIGH-BASED
THUNDERSTORMS. THIS MOISTURE TAP WILL CONTINUE TO STRETCH NORTH
INTO NORTHERN UTAH WHERE IT COULD INTERACT WITH THE WEAK VORTICITY
LOBE MOVING NORTH THROUGH WESTERN UTAH OVERNIGHT. THIS WEAK
DYNAMIC CONTRIBUTION TO LIFT ALONG WITH DECENT UPPER LEVEL
DIVERGENCE COULD SUPPORT SOME CONVECTION LATER TONIGHT/EARLY
FRIDAY.

THE ADVANCING UPPER LOW WILL BRING STEADILY INCREASING SYNOPTIC-
SCALE LIFT...MOISTURE AND INSTABILITY TO UTAH FOR LATE FRIDAY
THROUGH EARLY SATURDAY. THE AREAL EXTENT AND INTENSITY OF PRECIP
WILL INCREASE ON SATURDAY AS THE UPPER LOW EXPAND ACROSS A LARGE
PORTION OF THE GREAT BASIN...WITH MOST ACTIVE AREAS REMAINING
ACROSS SOUTHERN/CENTRAL UTAH INTO SATURDAY EVENING.

ACTIVITY WILL SHIFT TO THE NORTH ON SUNDAY AS THE CENTER OF THE
UPPER LOW SHIFTS EAST INTO NORTHERN COLORADO/SOUTHERN WYOMING.
SOLID WARM ADVECTION WRAP AROUND ACROSS SOUTHWEST WYOMING/NORTHERN
UTAH SHOULD SUPPLY SUFFICIENT LIFT FOR WIDESPREAD PRECIP SUNDAY
AND INTO SUNDAY EVENING.

.LONG TERM (AFTER 06Z MONDAY)...MID LEVEL TROUGH AXIS WILL CONTINUE
TO SHIFT SOUTHEAST INTO EASTERN UTAH SUNDAY NIGHT ALLOWING A DRIER
FLOW ALOFT TO MOVE INTO THE STATE FROM THE NORTHWEST MONDAY. HAVE
TRENDED TO DECREASE POPS TO ISOLATED BY MONDAY AFTERNOON AS SUCH.

UPSTREAM THE NEXT TROUGH WILL BE TRANSLATING SOUTHEAST THROUGH IDAHO
MONDAY AFTERNOON INTO THE OVERNIGHT HOURS...WITH MEAN TRAJECTORY
TRENDING EAST INTO WYOMING INTO THE OVERNIGHT HOURS. THIS TRACK
LOOKS TO LARGELY LIMIT UPPER SUPPORT TO CENTRAL IDAHO AND POINTS
EAST...THOUGH A SHALLOW COLD FRONT LOOKS TO SNEAK INTO NORTHERN UTAH
BY TUESDAY MORNING. FRONTAL FORCING MAY BE JUST DEEP ENOUGH TO KICK
OFF LIGHT SHOWERS OVER THE NORTH TUESDAY...AND CONVERGENT MID LEVEL
FLOW GENERATED BY THE FRONTAL PROGRESSION MAY KICK OFF ISOLATED
CONVECTION OVER THE SOUTH. HAVE TRENDED GRIDS TO MENTION ISOLATED
POTENTIAL FOR BOTH OF THESE AREAS...THOUGH SUBTLE DIFFERENCES IN NET
AMPLIFICATION AND TIMING OF THIS TROUGH/FRONT CONTINUE TO EXIST IN
GLOBALS. REGARDLESS...TEMPS DO LOOK TO REMAIN COOL AND SLIGHTLY
BELOW NORMAL TUE/WED.

PATTERN THEREAFTER BEGINNING MIDWEEK TRENDS DRIER AND WARMER WITH
TEMPS REBOUNDING TO ABOVE SEASONAL NORMS BY WEEKS END.

&&

.AVIATION...THE SURFACE TROUGH ACROSS CENTRAL NEVADA WILL MAINTAIN
GUSTY SOUTHERLY WINDS ACROSS WESTERN UTAH INTO EARLY FRIDAY. FOR
THE KSLC TERMINAL GUSTY SOUTH WINDS MAY DROP OFF A BIT EARLY THIS
EVENING...THEN PICK UP AGAIN FROM THE SOUTH-SOUTHEAST LATER THIS
EVENING. HIGH-BASED BUT GENERALLY WEAK CONVECTION WILL FORM ACROSS
WESTER UTAH THIS EVENING ISOLATED SHOWERS AND THUNDERSTORMS COULD
FORM THIS EVENING...THOUGH THIS ACTIVITY WILL LIKELY STAY WEST OF
THE TERMINAL. THE HIGH-BASED NATURE OF THIS ACTIVITY COULD SIGNAL
THE POTENTIAL FOR MICROBURST WINDS OVERNIGHT.


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

$$

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