National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS65 KBOI 090359
AFDBOI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
859 PM MST SAT MAR 8 2014

.DISCUSSION...CURRENT FORECAST IS ON TRACK AS WET PACIFIC FRONTAL
SYSTEM BEGINS TO COME INLAND.  TIMING AND QPF/POP FORECASTS ARE
COMPLETELY IN LINE WITH LATEST MODELS INCLUDING NEW 00Z NAM.  RAIN
SHOULD START IN HARNEY COUNTY AROUND 08Z OR MIDNIGHT PST...ENTER WRN
IDAHO AROUND 09Z-12Z AND SOUTH-CENTRAL IDAHO 15Z-18Z.  WITH SNOW
LEVEL RISING TO NEAR 8000 FEET MSL PCPN WILL BE RAIN SUNDAY.  SNOW
LEVEL WILL STILL BE NEAR 7000 FEET MSL MONDAY WHEN RAIN IS STILL
FALLING BUT WILL LOWER SHARPLY AS RAIN ENDS.  RAIN AMOUNTS WILL
BE MODERATE TO HEAVY ESPECIALLY IN IDAHO NORTH OF THE SNAKE BASIN.
CURRENT FLOOD WATCH FOR THESE AREAS IS ENTIRELY REASONABLE AND
MAY BE UPGRADED OVERNIGHT OR SUNDAY MORNING TO URBAN/SMALL STREAM
FLOOD ADVISORY OR WARNING.  MAIN-STEM RIVERS ARE STILL WITHIN THEIR
BANKS BUT THE WEISER RIVER AT WEISER WILL GET WITHIN A HALF FOOT OF
BANKFULL.  NO UPDATES FOR NOW.

&&

.AVIATION...VFR. CONDITIONS WILL DETERIORATE LATE TONIGHT AS
POWERFUL SYSTEM MOVES SLOWLY MOVES INTO THE REGION. MOUNTAINS WILL
BECOME OBSCURED WITH SNOW AOA 7000 FT MSL. PRECIPITATION WILL SPREAD
ACROSS SE OREGON AROUND 06Z SUN AND ACROSS SW IDAHO AFTER 12Z SUN.
EXPECT LOW VFR CONDITIONS EXCEPT MVFR CONDITIONS IN KBKE AND KBNO
AND IFR CONDITIONS AT KMYL. SURFACE WINDS MAINLY SOUTH TO
SOUTHEASTERLY 10-20KT. WINDS ALOFT AT 10K FEET MSL...SOUTHWESTERLY
25-35KT INCREASING TO 35-45KT BY 15Z SUN.

&&

.PREV DISCUSSION...
SHORT TERM...TONIGHT THROUGH MONDAY...VERY WET PERIOD IS STILL ON
TAP FOR SE OREGON AND SW IDAHO SUNDAY AND MONDAY. A LONG FETCH OF
MOISTURE WITH SUB-TROPICAL ORIGINS WILL EDGE INTO SE OREGON AND THE
WEST CENTRAL MTNS TONIGHT AND SETTLE FURTHER SOUTH ON SUNDAY. THE
FIRST ROUND OF PRECIPITATION WILL BE COUPLED TO A STRONG W-SW FLOW
ALOFT AND WILL FAVOR THE MTNS AND LOWER ELEVATIONS ALONG THE
WINDWARD SIDE /SOUTH AND WEST SLOPES/. A PUSH OF MILD PACIFIC AIR
INCREASES SNOW LEVELS TO BETWEEN 7K AND 9K FEET ON SUNDAY WHERE THEY
REMAIN BEFORE A COLD FRONTAL PASSAGE DROPS THEM BACK TO 6K FEET ON
MONDAY. SO THE MAIN IMPACT WITH THIS WET SYSTEM WILL BE THE RAIN AND
POTENTIAL FOR FLOODING OF SMALL STREAMS AND FIELDS ALONG WITH THE
POTENTIAL FOR ROCK AND MUD SLIDES. AS SUCH HAVE ISSUED A FLOOD WATCH
FROM SUNDAY MORNING THROUGH MONDAY AFTERNOON. THAT IS WHEN MUCH OF
THE PRECIPITATION WILL FALL WITH LIQUID AMOUNTS TOTALING 1-2 INCHES
IN THE MTNS WITH 0.50-0.75 INCHES IN THE VALLEYS. A SHARP UPPER
TROUGH CROSSES THE AREA ON MONDAY LOWERING SNOW LEVELS AND
SCATTERING OUT PRECIPITATION FROM WEST TO EAST. HAVE INTRODUCED A
SLIGHT CHANCE OF THUNDERSTORMS FOR MONDAY GIVEN THE DYNAMICS OF THE
UPPER TROUGH AND INCREASED ELEVATED INSTABILITY WITH COOLING ALOFT.
AHEAD OF THE TROUGH WINDS ARE GUSTY OUT OF THE EAST AT LOWER
ELEVATIONS VEERING AROUND TO THE WEST-SOUTHWEST ALOFT.

LONG TERM...MONDAY NIGHT THROUGH SATURDAY...COLD FRONT WILL EXIT TO
THE EAST MONDAY NIGHT BUT COOL AND SHOWERY CONDITIONS WILL CONTINUE
THROUGH EARLY TUESDAY AS THE ASSOCIATED UPPER LEVEL TROUGH TRAVERSES
IDAHO. SNOW LEVELS GENERALLY 3500 TO 4500 FT MSL THROUGH SUNRISE
TUESDAY. WARMER AND DRIER CONDITIONS WEDNESDAY THROUGH SATURDAY AS
AN UPPER LEVEL RIDGE BUILDS OVER THE WESTERN U.S. EXPECT HIGHS TO
REACH UPPER 40S IN THE MOUNTAINS /AND LOWER 60S ACROSS LOWER
VALLEYS/ BY SATURDAY.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...FLOOD WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING
     IDZ011-013-033.
OR...NONE.

&&

$$

WEATHER.GOV/BOISE

DISCUSSION...LC
AVIATION.....KA
PREV SHORT TERM...DG
PREV LONG TERM....MT