205 
FXUS65 KBOI 031536
AFDBOI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
936 AM MDT THU APR 3 2014

.DISCUSSION...WEAK UPPER LEVEL RIDGE MOVING THROUGH THE AREA THIS
MORNING WITH DRY CONDITIONS OVER SE OREGON AND SW IDAHO.
INCREASING HIGH LEVEL CLOUDS THIS AFTERNOON AHEAD OF A WEAK UPPER
LEVEL TROUGH MOVING INLAND OFF THE PACIFIC NORTHWEST COAST.
PRECIPITATION IS JUST STARTING TO REACH THE OREGON AND WASHINGTON
COAST. VERY MARGINAL INSTABILITY THIS AFTERNOON OVER HARNEY
COUNTY AND BAKER COUNTY FROM 21Z- 03Z...THUS ADDED A MENTION OF A
SLIGHT CHANCE OF THUNDERSTORMS TO THE FORECAST FOR THIS AFTERNOON.

&&

.AVIATION...VFR.  INCREASING HIGH LEVEL CLOUDS THROUGH THE DAY AHEAD 
OF THE NEXT WEATHER SYSTEM.  WIDELY SCATTERED SHOWERS WILL SPREAD 
INTO SOUTHEAST OREGON AFTER 21Z AND SOUTHWEST IDAHO AFTER 06Z.  SNOW 
LEVELS WILL BE AROUND 5K FEET MSL.  ISOLATED THUNDERSTORMS POSSIBLE 
OVER HARNEY COUNTY AND THE WESTERN SECTION OF BAKER COUNTY FROM 21Z 
THROUGH 03Z.  SURFACE WINDS SOUTHEAST TO SOUTHWEST 10 KNOTS OR 
LESS...EXCEPT GUSTY NEAR ANY THUNDERSTORMS.  WINDS ALOFT WILL BE 
NORTHWESTERLY AROUND 10 KNOTS THIS MORNING BECOMING SOUTHWEST BY
00Z.

&&

.PREV DISCUSSION...
SHORT TERM...TODAY THROUGH FRIDAY...UPPER RIDGE /CENTERED OVER
OREGON/ AND ACCOMPANYING DRY WEATHER WILL MOVE INTO IDAHO TODAY.
A PACIFIC TROUGH SITUATED TO THE WEST OF THE RIDGE WILL SPREAD
SHOWERS INTO SOUTHEAST OREGON LATE TODAY THROUGH TONIGHT...AND
INTO SOUTHWEST IDAHO ON FRIDAY. THE SYSTEM IS NOT STRONG AND IS
LACKING A MOIST SUBTROPICAL TAP...THUS RAIN/SNOWFALL AMOUNTS WILL
BE LIGHT. SNOW LEVELS WILL RISE TO BETWEEN 5000 AND 5500 FEET THIS
AFTERNOON...THEN FALL TO BETWEEN 4000 AND 5000 FEET TONIGHT
THROUGH FRIDAY. QPF TOTALS WILL RANGE FROM 0.10 TO 0.20 INCHES IN
THE MOUNTAINS WITH GENERALLY LESS THAN A TENTH /0.10/ OF AN INCH
IN THE VALLEYS. INSTABILITY IS MARGINAL FOR THUNDERSTORMS ON
FRIDAY...BUT KEPT SLIGHT CHANCE IN THE FORECAST FROM THE CAMAS
PRAIRIE TO SOUTHERN TWIN FALLS COUNTY FRIDAY AFTERNOON. TEMPS WILL
BE NEAR NORMAL TODAY AND SLIGHTLY BELOW NORMAL ON FRIDAY. WINDS
WILL NOT BE A CONCERN...GENERALLY 10 MPH OR LESS.

LONG TERM...FRIDAY NIGHT THROUGH THURSDAY...THE LAST OF THE
UPPER LEVEL TROUGH WILL MOVE ACROSS THE PACIFIC NORTHWEST SUNDAY
FOR PRECIPITATION MAINLY OVER HIGHER TERRAIN AND COOL
NORTHWESTERLY FLOW. NO CHANGES IN A LARGE UPPER LEVEL RIDGE
DEVELOPING OVER THE WESTERN U.S. BEGINNING MONDAY FOR ABOVE NORMAL
TEMPERATURES AND DRY CONDITIONS. THE HIGH AMPLITUDE OF THE RIDGE
IS DUE TO DEEPENING UPSTREAM /EASTERN PACIFIC/ LOW PRESSURE SYSTEM
AND DOWNSTREAM /EASTERN U.S./. HIGH CONFIDENCE TEMPERATURES WILL
BE 5-15 DEGREES ABOVE NORMAL STARTING MONDAY THROUGH WEDNESDAY.
MODELS SHOWING THE UPPER RIDGE BREAKING DOWN LATE NEXT WEEK BUT
CONFIDENCE IS LOW AS THE MODELS DON/T TYPICALLY HANDLE RIDGE
BREAKDOWNS VERY WELL. LATEST MODEL RUNS DELAY BRINGING THE PACIFIC
TROUGH INLAND UNTIL LATE THURSDAY WHICH ABOUT 24 HOURS LATER THAN
PREVIOUSLY SEEN.

&&

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

&&

$$

WEATHER.GOV/BOISE

DISCUSSION...KA/DG
AVIATION.....JA
PREV SHORT TERM...BW 
PREV LONG TERM....JS