Area Forecast Discussion
Issued by NWS Salt Lake City, UT

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

000
FXUS65 KSLC 020945
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
345 AM MDT MON MAY 2 2016

.SYNOPSIS...A WEAKENING LOW PRESSURE SYSTEM WILL MOVE ACROSS
SOUTHERN UTAH TODAY. HIGH PRESSURE WILL BRING A WARMING TREND
THROUGH MIDWEEK. THE NEXT PACIFIC TROUGH WILL ADVANCE INTO THE
GREAT BASIN LATE IN THE WEEK.

&&

.SHORT TERM (THROUGH 18Z THURSDAY)... WATER VAPOR LOOP SHOWS A
SHEAR ZONE ALONG THE ARIZONA BORDER WITH THE NEXT UPSTREAM WAVE
OVER CENTRAL CALIFORNIA. AMDAR 400-250MB WIND OBSERVATIONS PLACE A
SOUTHWESTERLY 90-125KT JET OVER THE SOUTHWEST CONUS INTO THE
PLAINS. GOES/HRRR/00Z KSLC RAOB INDICATE THE PRECIPITABLE WATER
VALUE RANGES FROM 0.15"-0.30" MOUNTAINS TO 0.40"- 0.60" MOST
VALLEYS.

CANYON WINDS CONTINUE TO DIMINISH ACROSS THE WASATCH FRONT...WAS
ABLE TO CANCEL THE WIND ADVISORY EARLY WITH THIS PACKAGE.

SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED ALONG AND SOUTH OF
INTERSTATE 70 THROUGH THIS EVENING IN THE VICINITY OF A SHEAR ZONE
ALOFT AND IN ADVANCE OF THE APPROACH OF THE CENTRAL CALIFORNIA WAVE.
CANT RULE OUT AN ISOLATED SHOWER OR STORM IN THE BOOK CLIFFS OR
UINTA MOUNTAINS. SREF ENSEMBLES INDICATE MODEST INSTABILITY IN PLACE
FOR THE AFTERNOON.

MUCH OF THE MOISTURE IS WITHING THE MIDLEVELS...WITH BUFKIT MODEL
FORECAST SOUNDINGS INDICATING AN INVERTED-V PROFILE AT THE LOWER
LEVELS ESPECIALLY IN THE VALLEYS. THEREFORE SOME OF THE CONVECTION
COULD POSE THE THREAT OF LOCALLY GUSTY/ERRATIC WINDS.

THIS ACTIVITY SHOULD DIMINISH GRADUALLY THROUGH THE EVENING HOURS
WITH LOSS OF DIURNAL INSTABILITY AND AS THE AFOREMENTIONED WAVE
SLIDES SOUTHEAST ACROSS ARIZONA.

A DRYING AND WARMING TREND IS FORECAST INTO MIDWEEK AS A RIDGE
AMPLIFIES OVERHEAD.

SOUTHERLY WINDS BEING TO GUST WEDNESDAY AFTERNOON ACROSS THE
WESTERN VALLEYS IN PARTICULAR IN ADVANCE OF A SPLITTING PACIFIC
TROUGH.

.LONG TERM (AFTER 18Z THURSDAY)...
RIDGE AXIS MOVES OVER PLAINS WHILE AN ELONGATED TROUGH MOVES ONTO
THE WEST COAST. THIS WILL BRING A BROAD AREA OF UNIDIRECTIONAL
SOUTHERLY FLOW ACROSS THE CWA. THIS TYPE OF FLOW WILL MEAN WEAK
DYNAMICS OVERALL...BUT CLOSER TO THE NEVADA BORDER INSTABILITY DUE
TO COOLING TEMPERATURES ALOFT WILL POSSIBLY INITIATE SOME MINOR
CONVECTION.

BETWEEN 06Z FRIDAY AND 18Z FRIDAY BOTH THE EC AND GFS ELONGATE THE
CLOSED LOW MORE EAST-WEST OVER SOUTHERN CALIFORNIA. THE EASTERN
EXTENSION OF THIS LOBE WILL ROTATE COUNTER CLOCKWISE ACROSS THE CWA
FRIDAY. SO WITH THE LACK OF DYNAMICALLY LIFT AHEAD OF THIS LOBE MOST
OF THE CWA SHOULD RECEIVE LITTLE IF ANY PRECIP THURSDAY NIGHT.
HOWEVER WITH THIS FEATURE IDENTIFIED BY BOTH MODELS...BELIEVE MOST
OF THE CWA WILL RECEIVE SCATTERED SHOWERS AS IT MOVES NORTHWARD
ACROSS THE CWA. HAVE BOOSTED POPS ACCORDINGLY FOR NOW...ALTHOUGH AS
WE GET CLOSER TO THE EVENT IT IS LIKELY WE`LL NEED TO BOOST THE POPS
EVEN MORE.

THE BROAD CIRCULATION WITH MULTIPLE WEAK LOBES ROTATING AROUND WILL
BE OVERHEAD SATURDAY. NOT KNOWING THE EXACT TIMING WAS NOT ABLE TO
PINPOINT WHERE THE BEST THREAT OF PRECIP WILL BE. THEREFORE HAVE
USED A BROAD BRUSH APPROACH AND PUSHED POPS ABOVE CLIMO.

BY SUNDAY THE CORE OF THE CIRCULATION IS EAST OF THE CWA BUT A MOIST
WRAP AROUND IS EXPECTED TO KEEP SHOWERS GOING THROUGH THE
DAY...MAINLY EASTERN PORTIONS AND MOUNTAINS. A FINAL LOBE IS
FORECAST TO SWEEP AROUND THIS EXITING LOW BY MONDAY WHICH
COULD BRING SOME MORE SHOWERS...ESPECIALLY ACROSS THE CENTRAL
AND SOUTHERN MOUNTAINS. TEMPERATURES ARE EXPECTED TO NEAR TO
SLIGHTLY BELOW NORMAL FROM FRIDAY THROUGH MONDAY.

&&

.AVIATION...NO WEATHER CONCERNS EXPECTED AT THE SLC TERMINAL TODAY.
WINDS WILL BE LIGHT SOUTHEAST THIS MORNING THEN SHIFT TO THE
NORTHWEST BETWEEN 17 AND 18Z THEN BACK TO SOUTHEAST AFTER 04Z THIS
EVENING.

&&

.FIRE WEATHER...
A WARMING/DRYING TREND THROUGH MID WEEK AS A RIDGE BUILDS IN.
THERE WILL BE ENOUGH REMNANT MOISTURE ACROSS PORTIONS OF SOUTHERN
UTAH FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS THROUGH
THIS EVENING.

SOUTHERLY WINDS BECOME GUSTY WEDNESDAY AND THURSDAY AHEAD OF A
SPRING STORM WHICH ARRIVES FRIDAY. FRIDAY THROUGH THE WEEKEND APPEAR
TO BE COOLER AND MORE MOIST WITH SCATTERED SHOWERS AND THUNDERSTORMS.

&&

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

$$

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



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.