507 
FXUS65 KBOI 280917
AFDBOI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
317 AM MDT FRI MAR 28 2014

.SHORT TERM...BRIEF BREAK THIS MORNING BEFORE NEXT MOIST PACIFIC
STORM COMES IN...PCPN BEGINNING THIS MORNING IN OREGON AND THIS 
AFTERNOON IN IDAHO.  AS IT SPREADS EAST UPPER LEVEL RIDGING WILL 
STEER THE MAIN PCPN NORTH AND AREAS NEAR THE NEVADA BORDER WILL HAVE 
LITTLE OR NO RAIN TODAY ESPECIALLY ON THE IDAHO SIDE.  BUT THE 
STORM IS VERY MOIST...AND LATE TONIGHT AND SATURDAY THE PCPN SHIELD 
WILL BEGIN TO SHIFT SOUTH AGAIN EVENTUALLY BRINGING PCPN TO ALL 
ZONES.  PCPN WILL BE QUITE HEAVY ON THE IDAHO SIDE ESPECIALLY NORTH 
OF THE SNAKE BASIN.  THIS WILL INCREASE RUNOFF IN THE CREEKS AND 
STREAMS.  AREAL FLOOD WATCH WILL CONTINUE IN THE ZONES LISTED BELOW.
SNOW LEVEL WILL RISE FROM 3500-4500 FEET MSL THIS MORNING TO 4500-
5500 FEET THIS AFTERNOON...TO A MAXIMUM OF 6000-6800 FEET SATURDAY 
MORNING...THEN LOWERING TO 5000 FEET BEHIND A COLD FRONT IN BAKER 
COUNTY TO 6300 FEET IN TWIN FALLS COUNTY SATURDAY AFTERNOON. ONE TO
TWO FEET OF SNOW WILL FALL AT HIGH ELEVATIONS...GREATEST AMOUNTS IN 
THE NOISE MOUNTAINS. NO THUNDERSTORMS EXPECTED TODAY DUE TO WARMING 
ALOFT...BUT COOLING ALOFT SATURDAY WILL ALLOW A CHANCE OF 
THUNDERSTORMS IN NRN ZONES SATURDAY AFTERNOON.  GENERALLY LIGHT TO 
MODERATE SE WINDS IN IDAHO AND SW WINDS IN OREGON TODAY...BECOMING 
LIGHT TO MODERATE WEST OR NW WINDS SATURDAY BEHIND COLD FRONT.

.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...A COOL AND SHOWERY 
WEATHER PATTERN WILL CONTINUE THROUGH THE PERIOD. THE UPPER LEVEL 
PATTERN WILL FAVOR A DEEP TROUGH JUST OFF THE U.S WEST COAST WHILE 
INDIVIDUAL SHORT WAVES PEEL OFF FROM THE MAIN TROUGH AND MOVE 
EASTWARD THROUGH OREGON AND IDAHO. THE SHORT WAVE EXPECTED TO MOVE 
THROUGH THE AREA SATURDAY NIGHT AND SUNDAY MORNING WILL HAVE A 
DECENT MOISTURE TAP...WHICH WILL BRING ANOTHER ROUND OF RAIN TO 
VALLEY LOCATIONS AND SNOW IN THE MOUTAINS ABOVE ABOUT 5000 FEET. THE 
EXACT TIMING OF SHORT WAVES LATER IN THE WEEK IS A BIT MORE 
UNCERTAIN...BUT CURRENT MODELS INDICATE THAT ANOTHER SYSTEM WILL 
COME THROUGH THE AREA ON TUESDAY WITH MORE VALLEY RAIN SHOWERS AND 
MOUNTAIN SNOW SHOWERS. THERE MIGHT BE A SHORT BREAK IN THE SHOWER 
ACTIVITY ON WEDNESDAY AND THURSDAY...BUT BOTH THE GFS AND ECMWF 
INDICATE UNSETTLED WEATHER RETURNING TO THE AREA BY THURSDAY NIGHT 
OR FRIDAY.
 
 &&

.AVIATION...SCATTERED RAIN AND SNOW SHOWERS WILL INCREASE ACROSS 
EASTERN OREGON THIS MORNING AND SPREAD EASTWARD INTO IDAHO THIS 
AFTERNOON.  MOST OF THE SHOWER ACTIVITY IN IDAHO WILL REMAIN NORTH 
OF THE SNAKE RIVER TODAY. RAIN AND SNOW SHOWERS WILL BE ASSOCIATED 
WITH MVFR TO OCCASIONAL IFR CEILINGS AND VISIBILITY WITH MOUNTAINS 
OBSCURED.  SNOW LEVELS WILL BE AROUND 5000 FT MSL. EXPECT WESTERLY 
WINDS ALOFT AT AROUND 20 KTS WITH VARIABLE SURFACE WINDS. 

&& 

.HYDROLOGY...HEAVIEST PCPN IS EXPECTED LATE TONIGHT THROUGH SATURDAY
IN IDAHO NORTH OF THE SNAKE BASIN.  THIS TOGETHER WITH RISING SNOW
LEVEL WILL INCREASE THE THREAT OF FLOODING IN STREAMS AND CREEKS
BUT MAIN-STEM RIVERS ARE NOT EXPECTED TO FLOOD.  ALSO...THE POTENTIAL
FOR ROCK AND MUD SLIDES WILL INCREASE IN STEEP TERRAIN.  FLOOD
WATCH /BOIFFABOI/ WILL CONTINUE IN ZONES LISTED BELOW.

&&



.BOI WATCHES/WARNINGS/ADVISORIES...
ID...FLOOD WATCH FROM THIS AFTERNOON THROUGH SATURDAY AFTERNOON 
     IDZ011-013-033.
OR...NONE.

&&

$$

WEATHER.GOV/BOISE

SHORT TERM...LC
LONG TERM....JB
AVIATION.....JB
HYDROLOGY....LC