Weather Service Report


904 
FXUS65 KBOI 292109
AFDBOI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
309 PM MDT FRI APR 29 2016

.SHORT TERM...TONIGHT THROUGH SUNDAY...SCATTERED SHOWERS WILL
CONTINUE OVER MOST OF SOUTHWESTERN IDAHO AND EASTERN OREGON
THROUGH THIS EVENING. RADAR AND SURFACE OBSERVATIONS SHOW RAIN IN
THE VICINITY OF BAKER CITY OREGON AND MCCALL IDAHO LATE THIS AFTERNOON
AND THESE SHOWERS WILL GENERALLY MOVE TOWARDS THE SOUTH EAST. THERE
IS ALSO A SLIGHT CHANCE OF THUNDERSTORMS IN IDAHO THROUGH THE
EARLY EVENING HOURS.  THE UPPER LEVEL LOW RESPONSIBLE FOR THIS
ACTIVITY IS CENTERED NEAR MISSOULA MONTANA BUT IS SLOWLY WEAKENING.
MEANWHILE THE SURFACE PRESSURE GRADIENT WILL STRENGTHEN AND CAUSE
BREEZY CONDITIONS DURING THE DAY ON SATURDAY IN EASTERN OREGON AND
IN THE TREASURE VALLEY OF IDAHO. SHOWER ACTIVITY WILL DECREASE
OVERNIGHT...BUT A FEW SNOW SHOWERS WILL REMAIN OVER THE IDAHO
MOUNTAINS INTO SATURDAY. SUNDAY LOOKS MOSTLY DRY WITH LESS WIND AS
AN UPPER LEVEL RIDGE BEGINS TO BUILD INTO THE WESTERN U.S.
TEMPERATURES WILL WARM TO A FEW DEGREES ABOVE NORMAL ON SUNDAY
UNDER MOSTLY SUNNY SKIES.

.LONG TERM...SUNDAY NIGHT THROUGH WEDNESDAY...MODEL AGREEMENT IS
ABOVE AVERAGE. THE HIGH PRESSURE RIDGE ALOFT CENTERED OVER SOUTHWEST
CANADA WILL KEEP MOST OF OUR AREA DRY THROUGH TUESDAY NIGHT.
PRECIPITATION ASSOCIATED WITH A LOW PRESSURE SYSTEM OVER THE GREAT
BASIN AND COLORADO PLATEAU IS NOT EXPECTED TO COME ANY CLOSER THAN
THE NEVADA BORDER. ON WEDNESDAY THE CHANCE OF SHOWERS WILL INCREASE
ACROSS SOUTHEAST OREGON AND THE CENTRAL IDAHO MOUNTAINS AS A TROUGH
DEVELOPS OFF THE WEST COAST AND THE RIDGE SHIFTS EAST. INCREASING
SOUTHERLY FLOW ALOFT AND EASTERLY FLOW AT THE SURFACE WILL RESULT IN
A WARMING TREND. TEMPERATURES WILL RISE FROM AROUND 5 DEGREES ABOVE
NORMAL ON MONDAY TO AROUND 10 DEGREES ABOVE NORMAL ON WEDNESDAY. 

WEDNESDAY NIGHT THROUGH FRIDAY...THE NEXT LOW SITS OFF THE
CALIFORNIA COAST WITH SOUTHERLY WINDS OVER THE REGION. OREGON ZONES
WILL START SEEING AN INCREASE IN MOISTURE THURSDAY WITH A STEADY
INCREASE THROUGH THE PERIOD. BY FRIDAY ALL ZONES WILL SEE MOISTURE.
INSTABILITY IS ENOUGH TO GENERATE SOME AFTERNOON
THUNDERSTORMS...MOSTLY FOR HIGHER ELEVATIONS. THE SOUTHERLY WINDS
WILL HELP KEEP TEMPERATURES WELL ABOVE NORMAL.

&&

.AVIATION...MAINLY VFR. EXPECT SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS THROUGH THIS EVENING...WITH AREAS OF TERRAIN
OBSCURATION AND LOCAL MVFR/IFR CEILINGS IN THE MOUNTAIN VALLEYS.
AFTER 06Z PRECIPITATION WILL END AT LOWER ELEVATIONS BUT SCATTERED
SHOWERS WILL CONTINUE THROUGH SATURDAY OVER THE CENTRAL IDAHO
MOUNTAINS AND HIGHER TERRAIN SOUTH OF THE SNAKE RIVER VALLEY. SNOW
LEVELS 6K-7K FT MSL...LOWERING TO 5K-6K FT MSL AFTER 06Z...THEN
RISING ABOVE 7K FT MSL AFTER 18Z. SURFACE WINDS...NORTHWEST 10-20
KTS. WINDS ALOFT...NORTH 10-20 KTS THROUGH 10K FT MSL. 

OUTLOOK FOR SATURDAY NIGHT AND SUNDAY...SCATTERED SHOWERS OVER THE
HIGHER TERRAIN OF CENTRAL AND SOUTHEAST IDAHO BEFORE 06Z SUNDAY.
PATCHY LATE NIGHT/EARLY MORNING VALLEY FOG...OTHERWISE VFR WITH
MOSTLY CLEAR SKIES. 

.HYDROLOGY...SMALL STREAMS ACROSS SOUTHERN IDAHO CONTINUE TO RUN
NEAR BANK FULL. THE BRUNEAU RIVER LOOKS LIKE IT HAS CRESTED THIS
AFTERNOON ABOUT 1 FOOT BELOW FLOOD STAGE AND IS FORECAST TO SLOWLY
RECEDE THROUGH THE WEEKEND WITH ONLY SMALL AMOUNTS OF
PRECIPITATION FORECAST IN THE HEAD WATERS. WITH TEMPERATURES NEAR
NORMAL TO ONLY A FEW DEGREES ABOVE BY SUNDAY...SNOW MELT IS NOT
EXPECTED TO BE ENOUGH TO CAUSE MUCH CONCERN FOR FLOODING.
HOWEVER...WE WILL CONTINUE TO CAREFULLY MONITOR THE SITUATION
IN CASE MORE RAIN THAN IS EXPECTED OCCURS.

&&


.BOI WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
OR...NONE.

&&

$$

WWW.WEATHER.GOV/BOISE
WWW.FACEBOOK.COM/NWSBOISE
WWW.TWITTER.COM/NWSBOISE

SHORT TERM...JB/MS
LONG TERM....JT/JC
AVIATION.....JT

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