Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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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)


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