Weather Service Report


556 
FXUS65 KPIH 122052
AFDPIH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
152 PM MST FRI FEB 12 2016

.SHORT TERM...TONIGHT THROUGH MONDAY NIGHT. AN UPPER LEVEL RIDGE
IS CURRENTLY IN PLACE ACROSS SOUTHEAST IDAHO...MAINTAINING DRY
WEATHER AND ABOVE NORMAL TEMPERATURES ABOVE VALLEY INVERSIONS. THIS
RIDGE WILL QUICKLY RETREAT EASTWARD OVERNIGHT AS A QUICK-MOVING
DISTURBANCE SLIDES EASTWARD ACROSS THE NORTHERN ROCKIES LATE
TONIGHT AND SATURDAY. AS A RESULT...A GRADUAL INCREASE IN SNOW
SHOWER ACTIVITY WILL BE FOUND ACROSS THE CENTRAL MOUNTAINS AND
MONTANA AND WYOMING BORDER HIGHLAND AREAS ON SATURDAY...WITH
AMOUNTS GENERALLY AN INCH OR LESS. A SECOND WAVE WILL PROVIDE A
MORE SUBSTANTIAL INCREASE IN SNOW SHOWER ACTIVITY FOR SUNDAY...AS
THIS SECOND SYSTEM WILL HAVE THE BENEFIT OF A GREATER SUPPLY OF
ATTENDANT MOISTURE. THE CENTRAL MOUNTAINS AND UPPER SNAKE/EASTERN
HIGHLANDS WILL RECEIVE THE MOST SNOWFALL WITH THIS ACTIVITY AND
FOR THESE AREAS SNOWFALL IS EXPECTED TO BE FALLING THROUGH THE DAY
SUNDAY. SNOWFALL WILL QUICKLY TAPER OFF AS ONE DESCENDS DOWN IN
ELEVATION TOWARDS THE SNAKE PLAIN AND EASTERN MAGIC VALLEY WHERE
RAIN AND RAIN/SNOW SHOWERS ARE ANTICIPATED. SNOWFALL ACCUMULATIONS
ALONG THE INTERSTATE CORRIDOR ON SUNDAY ARE EXPECTED TO RANGE FROM
A TRACE IN THE BURLEY AREA TO CLOSER TO ONE INCH FROM IDAHO FALLS
TO THE MONTANA BORDER WITH HIGHER AMOUNTS TOWARDS MONIDA PASS. 
SNOW ACCUMULATIONS FOR THE EASTERN HIGHLANDS SUNDAY ARE EXPECTED
TO BE IN THE 2 TO 5 INCH RANGE...WITH NORTHWEST SLOPES
FAVORED. SLIGHTLY LESS SNOWFALL FOR THE CENTRAL MOUNTAINS. WINDS
WILL BE ANOTHER IMPACT ASSOCIATED WITH THIS SYSTEM. SOUTHWEST
WINDS WILL INCREASE INTO THE 20 TO 30 MPH RANGE WITH HIGHER GUSTS
BY SUNDAY AFTERNOON...CREATING SOME DIFFICULT TRAVEL FOR HIGH
PROFILE VEHICLES. THIS WIND WILL ALSO LIKELY CREATE AREAS OF BLOWING
SNOW...PARTICULARLY AT PASS LEVEL.

MOIST NORTHWEST FLOW IS EXPECTED TO PERSIST SUNDAY NIGHT AND
THROUGH MONDAY...WITH SNOW SHOWERS CONTINUING PARTICULARLY ACROSS
THE EASTERN HIGHLANDS AND WYOMING BORDER REGION. WINDS WILL REMAIN
ELEVATED WITH THE POTENTIAL FOR BLOWING SNOW AT PASS LEVEL TO
CONTINUE. ADDITIONAL ACCUMULATIONS MONDAY ARE EXPECTED TO BE
SIMILAR TO THOSE ON SUNDAY. A WINTER WEATHER ADVISORY MAY BE
REQUIRED FOR THE EASTERN HIGHLANDS AS THE EVENT DRAWS NEARER TO
HIGHLIGHT POTENTIAL IMPACTS...AS TRAVEL AND RECREATION WILL
BE NEGATIVELY IMPACTED ON SUNDAY AND MONDAY. AD/HEDGES

.LONG TERM...TUESDAY THROUGH FRIDAY. UPPER RIDGE SHOWS SIGNS OF
SHIFTING EAST TUESDAY PER GFS AND ECMWF. GFS ENSEMBLE MEMBERS HAVING
A HARD TIME WITH EVOLUTION OF UPSTREAM TROUGH/CUTOFF LOW IN THE EAST
PACIFIC. ECMWF FAVORS A DEEPER LOW THAN OPERATIONAL GFS...WHICH
MAINTAINS A MORE PROGRESSIVE...OPEN TROUGH. DESPITE THE UNCERTAINTY
OF UPPER-LEVEL FEATURES THE TIMING OF ONSET OF PRECIPITATION IS
VIRTUALLY THE SAME...WHICH IS WEDNESDAY NIGHT. GFS...BEING THE MORE
PROGRESSIVE OF THE 12Z RUNS...ENDS MOST OF THE PRECIP WITH THE
PASSAGE OF THE 500MB TROUGH LATE THURSDAY NIGHT WHEREAS THE ECMWF
DEPICTS THE UPPER LOW LIFTING ACROSS CALIFORNIA AND INTO IDAHO
AROUND THAT SAME TIME PERIOD...AND THUS KEEPS WET CONDITIONS OVER
THE REGION THROUGH ABOUT FRIDAY MORNING. TEMPS CONTINUE TO LOOK
WARMER THAN NORMAL THROUGH MOST OF THE WEEK. HINSBERGER


&&

.AVIATION...WITH UPPER RIDGING SHIFTING TO THE EAST TODAY AND NO
WIDESPREAD FOG/STRATUS FIELD OVER THE SNAKE PLAIN...EXPECT VFR
CONDITIONS AT THE TERMINALS THROUGH THE PERIOD. MODELS BRING THROUGH
A MID AND UPPER CLOUD CEILING IN THE OVERNIGHT HOURS WITH SOUTHERLY
WINDS INCREASING NEAR SUNRISE TOMORROW. CONDITIONS SHOULD INHIBIT
FOG/STRATUS DEVELOPMENT TOMORROW MORNING. HINSBERGER


&&

.PIH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

Return to Home page


Western Regional Climate Center, wrcc@dri.edu