Area Forecast Discussion
Issued by NWS Billings, MT

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FXUS65 KBYZ 021640
AFDBYZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
940 AM MST TUE FEB 2 2016

.UPDATE...
MINOR UPDATE THIS MORNING...MAINLY TO ADJUST SNOW CHANCES AND
CLOUD COVER THE REST OF TODAY. STILL REPORTS OF A PERSISTANT LIGHT
SNOW ACROSS SHERIDAN COUNTY...BUT RADAR TRENDS ARE CONTINUING TO
DECREASE ACROSS THIS REGION SO EXPECTING THE SNOWS TO BECOME MORE
SCATTERED. STILL LOOKING AT SOME INSTABILITY INTO TONIGHT...SO SNOW
SHOWERS TO REMAIN IN THE FORECAST THAT COULD PRODUCE A QUICK INCH
IN SPOTS WITH HEAVIER SHOWERS...ESPECIALLY FOR SOUTHEAST MT AND
NORTHERN WY. OTHERWISE...LOWERED CLOUD COVER IN WESTERN AREAS AS
WE ARE STARTING OUT THE DAY WITH QUITE A BIT OF SUNSHINE. PLENTY
OF CLOUDS EXPECTED THIS AFTERNOON WITH THE AFORMENTIONED
INSTABILITY. FRIEDERS

&&

.SHORT TERM...VALID FOR TDY AND WED...

.PREVIOUS DISCUSSION...
WATER VAPOR IMAGERY SHOWS DYNAMIC UPPER LOW OVER WESTERN KS WITH
STRONG DIFFLUENCE ACROSS THE CENTRAL PLAINS...AND WEAK NORTHWEST
FLOW OVER THE NORTHERN ROCKIES. WE ARE SEEING EFFECTS OF THE UPPER
LOW IN THE FORM OF WEAK ISENTROPIC ASCENT...WHICH ALONG WITH
FAIRLY STEEP MID LEVEL LAPSE RATES IS PRODUCING AREAS OF LIGHT
SNOW ACROSS OUR CENTRAL AND EAST PARTS. PCPN HAS BEEN STEADIEST
EAST OF THE BIGHORN MTNS COURTESY OF DEEP EASTERLY UPSLOPE FLOW.
SPOTTER REPORTS INDICATE UP TO 2 INCHES HAS FALLEN IN SHERIDAN...
AND THIS IS CONSISTENT WITH LOCAL WEBCAMS...THOUGH THE SNOTEL
REPORT OF 6 INCHES UP THE SLOPE AT TIE CREEK WOULD SUGGEST SOME
AREAS HAVE SEEN MORE THAN 2 INCHES AT SLIGHTLY LOWER ELEVATIONS.
EXPECT UPSLOPE FLOW AND SYNOPTIC SCALE ASCENT TO DIMINISH SOON...
BY 12-15Z THIS MORNING...SO DONT SEE A NEED FOR A WINTER
HIGHLIGHT AS PCPN WILL BEGIN TO TAPER OFF SOON. THAT BEING
SAID...WILL HIGHLIGHT IN WX STORY THE SNOWY ROADS FOR THE MORNING
COMMUTE DOWN IN SHERIDAN. FURTHER NORTH...WE ARE SEEING FAIRLY
PERSISTENT SCATTERED SNOW SHOWERS IN THE VICINITY OF CUSTER AND
HYSHAM WHICH HAVE LIKELY PRODUCED SOME ACCUMULATION DURING THE
NIGHT. LOW TO MID LEVEL CONVERGENCE WILL SHIFT SLOWLY EAST TODAY
AND WILL PAINT HIGHEST POPS FROM HYSHAM AND SHERIDAN OVER TO MILES
CITY AND BROADUS. EXPECT AREAS OF SNOW AND LOCAL ACCUMS TO AN INCH
IN THIS AREA TODAY. FURTHER WEST...LACK OF ASCENT AND ONSET OF
WEAK DOWNSLOPE WINDS WILL LIMIT PCPN POTENTIAL...THOUGH MID LEVEL
LAPSE RATES REMAIN STEEP ENOUGH TO PRODUCE ISOLD SNOW SHOWERS
LATER TODAY AND THIS EVENING. PASSAGE OF SHORTWAVE IN NW FLOW
ALOFT WILL ALLOW FOR SOME LIGHT PCPN TO LINGER IN OUR EAST TONIGHT
THRU EARLY WEDNESDAY...AFTER WHICH WEDNESDAY SHOULD BE A DRY DAY
ACROSS OUR CWA UNDER HEIGHT RISES AND WITH THE DEVELOPMENT OF
STRONGER DOWNSLOPE GRADIENTS. NEXT PACIFIC SHORTWAVE WILL BRING A
CHANCE OF SNOW SHOWERS TO OUR WESTERN MTNS BY LATE WEDNESDAY
NIGHT.

ONCE WE GET PAST TODAY THE MAIN FORECAST ISSUE WILL REVOLVE AROUND
WIND. SW-W WINDS WILL INCREASE ALONG THE FOOTHILLS WEDNESDAY WITH
GUSTS OF 45-55 MPH POSSIBLE IN THE GAP AREAS BY WEDNESDAY NIGHT.
LATEST MODEL TRENDS SUGGEST SOME SPLITTING OF THIS NEXT WAVE...
WHICH WILL ALLOW FOR A COMPONENT OF PRESSURE FALLS TO OUR SW
WEDNESDAY NIGHT. FOR THIS REASON WE MAY NOT QUITE SEE ADVISORY
LEVEL GUSTS AT LIVINGSTON AND NYE...BUT IT IS SOMETHING TO WATCH.

TEMPERATURES WILL TURN GRADUALLY WARMER OVER THE NEXT TWO DAYS...
WITH HIGHS IN THE LOWER TO MID 30S TODAY RISING TO THE MID OR
UPPER 30S WEDNESDAY. PRETTY CLOSE TO EARLY FEBRUARY NORMALS.

JKL

.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...


THE MAIN FOCUS IN THE EXTENDED IS A PERIOD OF GAP FLOW WINDS
SATURDAY TRANSITIONING INTO POST FRONTAL WINDS ACROSS THE AREA
SUNDAY.

THURSDAY WILL SEE A PACIFIC WAVE MOVE THROUGH...ALTHOUGH IT WILL
AGAIN SPLIT SENDING MOST OF THE ENERGY SOUTH OF THE AREA. THE
MOUNTAINS WILL SEE A CHANCE AT SNOW DURING THE DAY...BUT MOST OF
THE AREA SHOULD REMAIN DRY. FRIDAY INTO SATURDAY FLOW WILL BECOME
MORE ZONAL AHEAD OF THE NEXT PACIFIC WAVE.

THE PRESSURE GRADIENT WILL INCREASE DURING THE DAY SATURDAY
PRODUCING STRONG WINDS AT LIVINGSTON AND NYE. GUSTS OF 50 TO 60
MPH ARE POSSIBLE. AS THE COLD FRONT ASSOCIATED WITH THE PACIFIC
WAVE MOVES THROUGH...THE CHANCE FOR PRECIP INCREASES. WINDS
BEHIND THE FRONT WILL INCREASE WITH GUSTS TO 50 MPH POSSIBLE
ACROSS MUCH OF THE AREA.

MODELS BECOME INCREASING DIVERGENT EARLY NEXT WEEK DUE TO
UNCERTAINTY WITH HIGH AMPLITUDE RIDGE OVER THE WEST COAST.
GUIDANCE FROM THE GFS AND EC FOR HIGHS IN BILLINGS ON TUESDAY
RANGE FROM 30 TO 58 DEGREES. HAVE GONE WITH THE CONSENSUS BLEND
GIVEN THE DRAMATIC DIFFERENCES. REIMER

&&

.AVIATION...

AN AREA OF SNOW CONTINUES ACROSS SOUTH CENTRAL MONTANA AND NORTH
CENTRAL WYOMING. MVFR CONDITIONS... WITH LOCALIZED IFR
CONDITIONS... WILL CONTINUE THIS MORNING WITH THESE SHOWERS.
CONDITIONS WILL BE IMPROVING THIS AFTERNOON. MROWELL

&&

.PRELIMINARY POINT TEMP/POPS...

    TDY WED     THU     FRI     SAT     SUN     MON
-------------------------------------------------------
BIL 032 019/035 022/040 027/043 030/048 030/043 026/041
    2/J 21/B    00/N    11/N    01/N    22/W    11/N
LVM 028 014/031 021/037 023/039 028/042 027/038 022/037
    2/J 21/N    12/J    31/N    11/N    22/W    11/N
HDN 035 017/036 015/042 024/043 025/047 027/043 021/040
    3/S 21/B    00/E    11/B    11/B    22/W    11/N
MLS 033 018/036 015/041 026/045 029/049 029/041 022/035
    3/S 21/B    01/E    11/U    11/B    22/W    11/N
4BQ 032 017/034 014/040 024/043 025/047 026/041 022/035
    5/S 22/J    01/B    11/B    01/B    22/W    12/J
BHK 030 017/032 012/037 024/042 027/047 027/038 018/031
    2/S 22/J    01/B    11/B    01/B    23/W    22/J
SHR 029 011/031 008/037 021/040 021/047 024/038 020/035
    6/S 22/J    00/E    21/U    11/B    23/W    22/J

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.

&&

$$
WEATHER.GOV/BILLINGS


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