Weather Service Report


545 
FXUS65 KBYZ 221515
AFDBYZ

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT 
915 AM MDT FRI AUG 22 2014

.UPDATE...
FIRST WAVE/SURGE OF ENERGY LIFTING NORTH OF OUR FORECAST AREA THIS
MORNING WITH RADAR ECHOES MAINLY ACROSS THE NORTHWEST/NO0RTH
CENTRAL SECTIONS. NEXT WAVE NOTED ON SATELLITE AND RADAR TO THE
SOUTH MOVING INTO WESTERN/NORTHWEST WYOMING AT THIS TIME.
MESOSCALE MODEL PRODUCTS SIMILAR IN PROGRESSION OF THIS WAVE
MOVING INTO SOUTHERN MONTANA MID TO LATE AFTERNOON AND PRODUCING A
GOOD DEAL OF QPF OVERNIGHT OVER OUR FORECAST AREA. THERE IS SOME
INDICATION THAT STRONGER CELLS MAY DEVELOP FROM SHERIDAN COUNTY
EASTWARD INTO POWDER RIVER AND CARTER COUNTIES EARLY THIS EVENING.
I HAVE ADDED A MENTION OF STRONG WINDS WITH THUNDERSTORMS IN THIS
AREA. TWEAKED TEMPS AND WIND FORECASTS AS WELL. REST OF FORECAST
IN GOOD SHAPE. BT

&&

.SHORT TERM...VALID FOR TDY AND SAT...

A COOL AND WET PATTERN IS SETTING UP ACROSS MONTANA TODAY THROUGH
SATURDAY AS THE UPPER JET STREAM HAS DEVIATED WELL SOUTH OF ITS
NORMAL TRACK FOR THIS TIME OF THE YEAR. NORMAL TRACK OF THE JET
STREAM IS ACROSS CANADA. THE STRONG 100KT JET IS DIVING SOUTHEAST
ACROSS THE PACIFIC NORTHWEST AND HAS CARVED OUT A LARGE TROUGH OF
LOW PRESSURE OVER MONTANA. UPPER TROUGH IS BRINGING AN INCREASING
DIFFLUENT FLOW ALOFT ALONG WITH ABUNDANT MOISTURE AND SEVERAL
STRONG SHORT WAVE EJECTING OUT OF THE BASE OF THE TROUGH. ONE WAVE
WILL MOVE THROUGH THIS MORNING BRINGING SHOWERS AND ISOLATED
THUNDERSTORMS TO THE WESTERN AND CENTRAL ZONES. THIS PRECIP WILL
SPREAD INTO SOUTHEAST MONTANA THIS AFTERNOON WHERE A FEW VERY
ISOLATED STORMS COULD BE STRONG ALONG AND EAST OF A LINE FROM
MILES CITY TO BROADUS. SOUNDINGS INDICATE CAPES AROUND 500 J/KG
BUT SUFFICIENT SHEAR OF 40KTS WILL BE IN PLACE. DO NOT EXPECT ANY
SEVERE WEATHER BUT MAIN THREAT FROM ANY STORMS TODAY AND TONIGHT
ACROSS THE FORECAST AREA WILL BE HEAVY RAINFALL. PATCHY DENSE FOG
HAS DEVELOPED OVER MUSSELSHELL COUNTY AND THIS SHOULD CONTINUE
THERE THROUGH THE MORNING HOURS.

SATURDAY WILL REMAIN COOL AND WET AS MODELS INDICATED A CLOSED
UPPER LEVEL LOW PRESSURE SYSTEM DEVELOPING OVER SOUTHWEST MONTANA.
THIS WILL BRING STRONG Q VECTOR FORCING ACROSS OUR FORECAST AREA.
SURFACE LOW ALSO DEVELOPING OVER NORTHERN WYOMING SATURDAY WHICH
WILL BRING DEEPENING UPSLOPE FLOW AND ADDITIONAL LOW LEVEL
MOISTURE INTO THE REGION. SOUNDINGS CONTINUE TO SHOW THE AIR MASS
WILL BE SATURATED FROM THE SURFACE TO 300 MB. TOTAL PRECIPITATION
WILL RANGE FROM 1 TO 3 INCHES ACROSS SC/SE MT FROM THIS STORM
SYSTEM. SMALL STREAMS AND BURN SCARS MAYBE IMPACTED BY THIS
RAINFALL AND WILL BE MONITORED CLOSELY. PRECIPITATION WILL BEGIN
DECREASING SATURDAY NIGHT AS THE STORM SYSTEM LIFTS TO THE
NORTHEAST AWAY FROM OUR AREA. HIGH TEMPERATURES TODAY AND SATURDAY
WILL RUN 15 TO 20 DEGREES BELOW NORMAL. RICHMOND


.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...

EXTENDED MODELS GENERALLY ARE IN GOOD AGREEMENT TO BEGIN THE
PERIOD BUT DO DIVERGE TOWARD THE END OF NEXT WEEK. UPPER LOW AND
TROUGH WILL CONTINUE TO BE OVER THE NORTHERN ROCKIES SUNDAY WITH
MODELS PLACING THE LOW ACROSS THE VICINITY OF EASTERN
MONTANA/WESTERN NORTH DAKOTA. THIS WILL RESULT IN GUSTY WEST TO
NORTHWEST WINDS ACROSS OUR CENTRAL AND EASTERN PORTIONS OF THE
FORECAST AREA. CONDITIONS WILL SLOWLY DRY OUT BUT COLD AIR ALOFT
WILL KEEP THE INSTABILITY AROUND WITH SHOWER CHANCES CONTINUING.
HOWEVER...THE HEAVIER SHOWER ACTIVITY IS EXPECTED TO BE NORTH AND
EAST OF OUR FORECAST AREA.

THE UPPER LOW MOVES INTO SOUTHERN CANADA BY MONDAY BUT GENERAL
TROUGHINESS WILL REMAIN ACROSS THE STATE. DYNAMICS WILL BE MUCH
WEAKER SO ONLY A SLIGHT SHOWER CHANCE WILL BE POSSIBLE. WEAK
RIDGING FOLLOWED BY A ZONAL FLOW MOVE OVER THE FORECAST AREA
TUESDAY THROUGH THURSDAY BRINGING DRY CONDITIONS AND WARMER
TEMPERATURES. MODELS HINT AT ANOTHER TROUGH AND UPPER LOW ARRIVING
BY NEXT FRIDAY BUT SIGNIFICANT DIFFERENCES EXIST WITH STRENGTH AND
TIMING. HOOLEY
&&

.AVIATION...

SHOWERS AND ISOLATED THUNDERSTORMS WILL INCREASE IN COVERAGE
TODAY AS A STRONG UPPER LOW MOVES INTO THE REGION. STRONG GUSTY
WINDS ARE POSSIBLE WITH THUNDERSTORMS ACTIVITY...WITH STRONGEST
GUSTS SOUTH OF A LINE FROM KSHR TO EKALAKA. EXPECT MANY AREAS TO
HAVE MVFR TO IFR CONDITIONS AT TIMES THROUGHOUT THE DAY. EXPECT
MOUNTAIN OBSCURATIONS THROUGHOUT THE DAY AS WELL. AAG/HOOLEY

&&

.PRELIMINARY POINT TEMP/POPS...

    TDY SAT     SUN     MON     TUE     WED     THU     
-------------------------------------------------------
BIL 067 055/064 048/067 048/071 050/075 053/082 057/087
    4/T 88/T    54/T    23/T    32/T    11/U    01/U
LVM 065 050/062 044/068 043/070 044/075 048/083 051/086
    7/T 87/T    63/T    25/T    52/T    11/B    01/U
HDN 074 055/067 051/069 046/074 050/077 051/083 055/088
    5/T 89/T    54/T    23/T    32/T    11/U    01/U
MLS 071 057/069 052/065 048/071 051/074 053/082 057/087
    5/T 98/T    55/T    22/T    22/T    11/U    11/U
4BQ 076 059/073 053/066 047/071 052/073 051/081 056/087
    4/T 88/T    63/T    22/T    33/T    11/U    11/U
BHK 070 055/068 052/065 045/069 047/071 048/078 053/083
    4/T 99/T    84/T    22/T    23/T    11/U    11/U
SHR 073 053/069 048/067 044/073 048/074 048/081 051/087
    5/T 77/T    53/T    23/T    33/T    11/U    01/U

&&

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

&&

$$
WEATHER.GOV/BILLINGS

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