National Weather Service Raw Text Product

961 
FXUS65 KSLC 140926
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
326 AM MDT MON SEP 14 2015

.SYNOPSIS...A COOL AND UNSETTLED PATTERN WILL CONTINUE THROUGH
MIDWEEK.

&&

.SHORT TERM (THROUGH 12Z WEDNESDAY)...
WATER VAPOR LOOP SHOWS A WAVE LIFTING NORTHEAST OVER CENTRAL
UTAH. ANOTHER DISTURBANCE REMAINS OFF THE CALIFORNIA COAST AHEAD
OF A BUILDING TROUGH OVER THE PACIFIC NORTHWEST. AMDAR 400-250MB
WIND OBSERVATIONS SHOW UTAH IS BETWEEN TWO JETS...A 80-135KT
CYCLONIC JET OVER WESTERN CANADA...AND A 50-75KT ANTICYCLONIC JET
OVER THE SOUTHWEST CONUS. GOES/GPS/RAP/00Z SLC RAOB INDICATE THE
PRECIPITABLE WATER VALUE RANGES BETWEEN 0.25"-0.40" NORTHERN
MOUNTAINS...TO 1.00"- 1.40" MOST SOUTHERN VALLEYS.

ACTIVE WEATHER NEXT SEVERAL DAYS...

WITH THE WAVE LIFTING NORTHEAST OVER CENTRAL UTAH THIS 
MORNING...RAIN SHOULD CONTINUE TO DEVELOP TO THE NORTH AND EAST. 
HAVE BUMPED UP POPS GIVEN UPSTREAM OBSERVATIONS AND HRRR-3KM 
GUIDANCE. WINDS COULD BE GUSTY/ERRATIC AS THE MOISTURE WORKS ITS WAY 
IN THIS MORNING.

FURTHER SOUTH...ITS QUITE SATURATED GIVEN RAINS DURING THE PAST 12 
HOURS. DEWPOINTS 50-60F ALONG THE ARIZONA BORDER AND RAP DEPICTION 
OF WARM CLOUD DEPTH OF 5-6.5KFT THIS AFTERNOON PRESENTS SOME CONCERN 
FOR LOCALLY HEAVY RAINFALL. HOWEVER STORM MOTIONS APPEAR ON THE 
ORDER OF 25KTS SO IT WOULD TAKE TRAINING STORMS FOR FLOODING ISSUES 
TO PRESENT THEMSELVES. HAVE OPTED FOR MODERATE FLASH FLOOD POTENTIAL 
FOR SOME OF THE SOUTHERN UTAH PARKS...AND ADDED LOCALLY HEAVY 
RAINFALL WORDING INTO THE FORECAST ACROSS THE SOUTH THIS AFTERNOON 
AND EVENING.

CONVECTION SHOULD BE MORE WIDESPREAD ACROSS THE NORTH THAN THE SOUTH 
THIS AFTERNOON. SHORTWAVE RIDGING NORMALLY SUPPRESSES 
CONVECTION...BUT LOOKING AT THE BIG PICTURE HAVE THE NOSE OF THE 
SOUTHERN JET POKING INTO UTAH THIS AFTERNOON AIDING IN LARGE SCALE 
ASCENSION.

OTHER STORY TODAY WILL BE THE GUSTY SOUTHWEST WINDS THAT MIX DOWN TO 
THE SURFACE ESPECIALLY ACROSS SOUTHERN UTAH WHERE MIXING WILL BE 
BETTER REALIZED.

OFFSHORE CALIFORNIA WAVE LIFTS THROUGH TONIGHT CONTINUING THREAT OF 
CONVECTION. IN FACT...GLOBAL MODELS HINT THAT UPPER LEVEL JETS MAY 
COUPLE INCREASING LARGE SCALE LIFT.

THE ARRIVAL OF A SHALLOW COLD FRONT ACROSS NORTHERN UTAH TUESDAY 
COULD ENHANCE PRECIPITATION. HOWEVER IT DOESNT LOOK AS POTENT AS THE 
WEDNESDAY SYSTEM.

.LONG TERM (AFTER 12Z WEDNESDAY)...
A VIGOROUS TROUGH WILL MOVE ACROSS THE INTERMOUNTAIN WEST THROUGH
THE DAY WEDNESDAY...WITH THE TIGHTEST PART OF THE LOW LEVEL
BAROCLINIC ZONE PUSHING THROUGH NORTHERN UTAH AND SOUTHWEST
WYOMING THROUGH THE DAYTIME HOURS. THIS FRONT SHOULD HELP PRODUCE
A PERIOD OF MODERATE TO HEAVY PRECIPITATION ACROSS THE NORTHERN
HALF OF THE CWA...AS WELL AS DECREASE TEMPERATURES NICELY AS IT
PASSES THROUGH...WITH SNOW LEVELS LIKELY TO DROP TO ABOUT 9000
FEET ACROSS NORTHERN UTAH. HAVE CONTINUED TO INCREASE POPS AND QPF
VALUES FOR WEDNESDAY...WITH SOME SNOW ACCUMULATION ON THE HIGHER
PEAKS.

THOUGH THE FRONT LOOKS TO BE FAIRLY STRONG ON WEDNESDAY...THE MID-
LEVEL COLD POOL LARGELY REMAINS NORTH OF THE CWA...SO THERE IS A 
CHANCE THAT SHOWERS DIE OFF RELATIVELY QUICKLY WEDNESDAY EVENING. 
THAT SAID...HAVE LEFT DECENT POPS IN THE MOUNTAINS INTO THE EVENING 
FOR NOW...WITH THE POSSIBILITY OF AT LEAST SOME LINGERING 
INSTABILITY AND A MOIST WESTERLY FLOW. 

THE FINAL WAVE ASSOCIATED WITH THE LARGE LONGWAVE TROUGH IS EXPECTED 
TO PUSH THROUGH NORTHERN UTAH ON THURSDAY. THE 00Z ECMWF TRENDED A 
LITTLE STRONGER AND FURTHER SOUTH WITH THIS SHORTWAVE...SO INCREASED 
POPS A BIT FOR THURSDAY AFTERNOON. ALSO KEPT TEMPERATURES FAIRLY LOW 
ACROSS THE NORTH WITH THIS REINFORCING SHOT OF COOL AIR.

AFTER THE TROUGH EXITS TO THE EAST THURSDAY NIGHT...A ZONAL FLOW IS 
FORECAST TO DEVELOP OVER MUCH OF THE WEST FRIDAY AND HEADING INTO 
THE WEEKEND...WITH A DRYING AND WARMING TREND. TEMPS ARE GENERALLY 
EXPECTED TO INCREASE TO NEAR SEASONAL NORMALS OVER THE WEEKEND. 
THERE IS A CHANCE THAT LOW TO MID LEVEL SOUTHERLY FLOW WILL INCREASE 
A BIT FOR THE BEGINNING OF NEXT WEEK...POTENTIALLY DRAWING MOISTURE 
UP INTO SOUTHERN UTAH. HAVE INCREASED CLOUD COVER AND INTRODUCED 
SOME SLIGHT CHANCE POPS FOR THE SOUTH ON MONDAY TO ACCOUNT FOR THIS 
POSSIBILITY...THOUGH AT THE MOMENT IT LOOKS LIKE TUESDAY OR 
WEDNESDAY MAY BE A BETTER BET FOR DEEPER MOISTURE TO MAKE IT THIS 
FAR NORTHWARD.

&&

.AVIATION...SOUTHERLY WINDS SHOULD GENERALLY REMAIN GUSTY AT THE SLC 
TERMINAL TODAY...AND PERIODS OF GUSTS GREATER THAN 30 MPH ARE 
POSSIBLE THROUGH MUCH OF THE DAY. SHOWERS WILL INCREASE ACROSS 
NORTHERN UTAH TODAY...WITH BRIEF CEILINGS BELOW 7000FT LIKELY UNDER 
THE STRONGER SHOWERS. THUNDERSTORMS ARE ALSO POSSIBLE...PARTICULARLY 
AFTER 18Z...AND COULD PRODUCE GUSTY ERRATIC WINDS AND CLOUD-TO-
GROUND LIGHTNING.

&&

.FIRE WEATHER...MOIST AND COOLER THROUGH MID WEEK AS A SERIES OF 
DISTURBANCES AFFECT THE EASTERN GREAT BASIN. EXPECT PERIODS OF 
WETTING RAIN AND LIGHTNING WITH A SNOW LEVEL ABOVE 11KFT THROUGH 
TUESDAY. SNOW LEVEL MAY DROP TO 9KFT ACROSS THE NORTH WEDNESDAY WITH 
THE COLDEST OF THE SYSTEMS. 

THERE COULD BE SOME GUSTY/ERRATIC WINDS ACROSS NORTHERN UTAH THIS 
MORNING ON THE PERIPHERY OF BUILDING MOISTURE MOVING IN FROM THE 
SOUTH. 

EXPECT A RECOVERY IN TEMPERATURES AND DRIER CONDITIONS BY NEXT 
WEEKEND.

&&

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

$$

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

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