Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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378
FXUS65 KSLC 030949
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
349 AM MDT TUE MAY 3 2016

.SYNOPSIS...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 FRIDAY)...
WATER VAPOR LOOP SHOWS A RIDGE BUILDING IN FROM THE NORTH AS A
SHORTWAVE SLIDES ACROSS NORTHEAST ARIZONA. AMDAR 400-250MB WIND
OBSERVATIONS PLACE A WESTERLY 50-80KT JET OVER THE ARIZONA BORDER.
A SECOND CYCLONIC JET OF SIMILAR MAGNITUDE IS OVER THE EASTERN
PACIFIC. GOES/HRRR/00Z KSLC RAOB INDICATE THE PRECIPITABLE WATER
VALUE RANGES FROM 0.10"-0.20" MOUNTAINS TO 0.25"-0.50" MOST
VALLEYS.

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

SOUTHERLY WINDS BEING TO GUST WEDNESDAY AFTERNOON AND STRENGTHEN
THURSDAY IN ADVANCE OF A SPLITTING PACIFIC TROUGH. GUSTS MAY NEAR
ADVISORY LEVELS ACROSS A FEW WESTERN VALLEYS THURSDAY AFTERNOON AS
700MB WINDS INCREASE TO 30-35KTS WITH 8-10MB/6HR PRESSURE FALLS
THOUGH GRADIENT DOESNT LOOK TOO STRONG YET.

EXPECT ISOLATED CONVECTION TO DEVELOP ON THE HIGHER TERRAIN THURSDAY
AFTERNOON. SHORT RANGE ENSEMBLES SUGGEST INCREASING INSTABILITY
PERSISTING THROUGH THURSDAY NIGHT AND FRIDAY MORNING PARTICULARLY
ACROSS EASTERN AND NORTHERN ZONES. HAVE RAISED POPS IN THESE AREAS
OF SHOWERS/STORMS. SNOW LEVELS LOOK TO BE 8-10KFT IN THE WARM SECTOR.

.LONG TERM (AFTER 18Z FRIDAY)...
THE POSITION OF THE LARGE CLOSED LOW BY BOTH THE GFS AND EC ARE
QUITE SIMILAR OVER SOUTHERN CALIFORNIA. THE DIFFERENCES COME WITH
THE LOBE OF ENERGY ROTATING NORTHWARD ACROSS THE CWA FRIDAY
AFTERNOON. THE GFS IS A LITTLE SHARPER AND FASTER WITH THIS
LOBE...RESULTING IN A SLIGHTLY BETTER CHANCE OF SHOWERS ACROSS
NORTHERN PORTIONS OF THE CWA LATE AFTERNOON AND EVENING WHILE THE
EC WOULD ARGUE FOR A SLOWER AND WEAKER LOBE THAT WOULD BRING
SCATTERED SHOWERS TO CENTRAL AND NORTHERN UTAH. TOOK A BROAD BRUSH
APPROACH AND RAISED THE POPS ACROSS THE NORTH BUT CONFIDENCE LOW
FOR REST OF CWA SO WENT NEARER CLIMO. WITH THE LOW MEANDERING
OVERHEAD SATURDAY INTO SUNDAY KEPT THE POPS SLIGHT ABOVE CLIMO
THROUGH THIS PERIOD AS HARD TO DISTINGUISH WHERE THE BEST DYNAMIC
LIFT WILL BE. ELECTED TO REMOVE THUNDERSTORMS FROM THE OVER NIGHT
MORNING FORECAST FOR SATURDAY NIGHT AND SUNDAY NIGHT AS WELL AS
LOWERED POPS SOME.

THIS LOW IS NOT AS COLD AS THE PREVIOUS CLOSED LOWS THAT HAVE MOVED
THROUGH THE AREA SO KEPT TEMPERATURES UP SOME FROM PREVIOUS
STORMS.

BY MONDAY THE GFS HAS THE LOW FINALLY SLOWLY EXITING THE REGION BUT
LINGERING MOISTURE WILL PROBABLY BE ENOUGH TO SET OFF A FEW SHOWERS
AND THUNDERSTORMS OVER THE HIGHER TERRAIN AS WELL AS IN EASTERN
AREAS AND ADJACENT VALLEYS. THE EC IS FASTER IN EXITING THE LOW
WITH RIDGE BUILDING IN BY LATE IN THE DAY. TRENDED POPS DOWNWARD
FOR MONDAY INTO TUESDAY AS FLOW BECOMES NORTHWEST.

&&

.AVIATION...SOUTHEAST WINDS WILL PREVAIL AT THE SLC TERMINAL THROUGH
ABOUT 17-18Z BEFORE SHIFTING TO THE NORTHWEST. THERE IS A 20
PERCENT CHANCE THAT THE WINDS SHIFT AS EARLY AS 16-17Z.

&&

.FIRE WEATHER...A WARMING/DRYING TREND THROUGH MID WEEK AS A
RIDGE BUILDS IN. SOUTHERLY WINDS BECOME GUSTY WITH AREAS OF LOW RH
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)



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