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000
FXUS65 KBYZ 152132
AFDBYZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
332 PM MDT SAT JUN 15 2013

.SHORT TERM...VALID FOR SUN AND MON...

A SUNNY TO MOSTLY SUNNY WEEKEND REMAINS ON TAP ACROSS OUR
FORECAST AREA ALONG WITH SEASONAL TEMPERATURES. UPPER LOW
CONTINUES TO SLOWLY MOVE EAST AND SOUTHEAST ACROSS SOUTHERN CANADA
INTO NORTH DAKOTA AND MINNESOTA LEAVING MOSTLY CLEAR SKIES FOR OUR
AREA. SUBSIDENCE ACROSS SOUTHERN MONTANA IS RESULTING IN A MOSTLY
SUNNY DAY BUT COLD AIR ALOFT COMBINED WITH A WEAK COLD FRONT
ACROSS THE NORTHEASTERN PORTIONS OF THE STATE HAS RESULTED IN
QUITE A BIT OF CUMULUS ACROSS THAT AREA. THIS FRONT WILL SLIDE
SOUTH THIS EVENING AND OVERNIGHT BRINGING A WIND SHIFT TO THE
NORTHEAST LATE TONIGHT AND THROUGH THE DAY SUNDAY.
HOWEVER...ATMOSPHERE REMAINS DRY SO NOT EXPECTING ANY PRECIP WITH
THE FRONT. A FEW CLOUDS WILL POSSIBLY WORK THEIR WAY SOUTH INTO
OUR FAR NORTH AND NORTHEAST ZONES BUT THESE ARE EXPECTED TO
DISSIPATE SHORTLY AFTER SUNSET. TEMPERATURES WILL BE A FEW DEGREES
WARMER TONIGHT FOR SOME AREAS BUT STILL EXPECT A CHILLY NIGHT ONCE
AGAIN WITH TEMPERATURES SLIGHTLY BELOW NORMAL.

HIGH PRESSURE RIDGING BEGINS TO BUILD ALONG WITH RISING HEIGHTS
SUNDAY AND ESPECIALLY INTO MONDAY. A FEW WEAK DISTURBANCES MAY
UNDERCUT THE RIDGE RESULTING IN A SLIGHT SHOWER/THUNDERSTORM
CHANCE MAINLY OVER THE MOUNTAINS AND NEARBY FOOTHILLS BOTH SUNDAY
AND MONDAY AFTERNOON/EVENING. HIGH TEMPERATURES SUNDAY WILL BE
AROUND AVERAGE WITH MIDDLE TO UPPER 70S WITH READINGS A FEW
DEGREES WARMER ON MONDAY. HOOLEY


.LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT...

RIDGING BEGINS BREAKING DOWN LATE TUES AS UPPER LEVEL FLOW BECOMES
INCREASINGLY SOUTHWESTERLY. SHORTWAVES EMBEDDED WITHIN THE FLOW
WILL WORK WITH SURFACE DEWPOINTS IN THE 40S TO LOW 50S...A BIT OF
SHEAR...AND DAYTIME INSTABILITY TO INCREASE CHANCES OF SHOWERS
AND THUNDERSTORMS ACROSS WESTERN AND CENTRAL AREAS...AS FAR EAST
AS BILLINGS AND SHERIDAN. FOR NOW...KEPT POPS LOW THROUGH TUES
EVE...BUT IF SHORTWAVE ACTIVITY LOOKS STRONGER AS TUES
APPROACHES...WE WILL NEED TO RAISE POPS. HIGH TEMPS WILL BE IN THE
80S.

MORE SHORTWAVE ACTIVITY IN SW FLOW ALOFT IS EXPECTED TO BRING
SHOWERS AND THUNDERSTORMS TO THE REGION WED...WITH THE BEST
CHANCES AGAIN ACROSS THE WEST AND CENTRAL WHERE STRONG UPPER LEVEL
JET ENERGY/DIVERGENCE WILL HELP TO DEEPEN A SURFACE
LOW AND INCREASE FRONTOGENETICAL AND LOW-LEVEL FORCING. SHEAR
LOOKS MARGINAL...BUT CAPE VALUES ARE QUITE HIGH WED AFTN/EVE...SO
NOT SURE ABOUT THE LIKELIHOOD OF SEVERE STORMS...BUT CERTAINLY
SOME STRONG STORMS ARE POSSIBLE. 700 MB TEMPS ACROSS THE EAST WED
AFTN/EVE WILL BE IN THE +12C TO +14C RANGE...WHICH MAY CAP THAT
REGION. SO...AT THIS POINT...LESS CONVECTIVE ACTIVITY IS EXPECTED
ACROSS THE EAST. WED NIGHT INTO THURS...THE SURFACE LOW MOVES
E...DRAGGING A COLD FRONT WITH IT. THIS WILL STABILIZE THE
ATMOSPHERE A BIT THROUGH A GOOD PORTION OF THURS. EXPECT HIGHS
AGAIN IN THE 80S ACROSS MUCH OF THE REGION WED...WITH HIGHS IN THE
70S THURS.

SHORTWAVE ENERGY ROUNDING THE BASE OF THE UPPER LEVEL TROUGH LATE
THURS INTO EARLY FRI WILL INCREASE UPPER LEVEL DIVERGENCE AND
POTENTIALLY HELP TO DEVELOP ANOTHER SURFACE LOW ACROSS SOUTHERN
MT/NORTHERN WY...SETTING THE STAGE FOR FURTHER CONVECTIVE
DEVELOPMENT ACROSS THE REGION. CONVECTION SHOULD FIRE OVER THE
WEST AND CENTRAL LATE THURS EVE...AND PROPAGATE EASTWARD THROUGH
THE OVERNIGHT HOURS AND INTO EARLY FRI AS THE LOW DRAGS ANOTHER
COLD FRONT THROUGH THE REGION. SHEAR VALUES LOOK SUFFICIENT FOR AT
LEAST STRONG STORMS LATE THURS INTO EARLY FRI MORNING...BUT LOW
LEVEL MOISTURE IS LOWER THAN WED...THUS CAPE VALUES ARE NOT ALL
THAT HIGH. WILL HAVE TO KEEP AN EYE ON SURFACE DEWPOINTS. IF THEY
RECOVER INTO THE 50S ACROSS THE EASTERN HALF OF THE REGION THURS
NIGHT...AS SUGGESTED BY THE ECMWF...THERE WILL BE A BETTER CHANCE
OF SOME STORMS BECOMING SEVERE.

FRI LOOKS TO BE A TOUCH COOLER THAN THURS ACROSS THE REGION
BEHIND THE FRONT WITH A MORE STABLE AIRMASS BUILDING
IN...ESPECIALLY BY LATER IN THE DAY. ANOTHER STRONG SHORTWAVE
TROUGH APPROACHES THE REGION SAT...INCREASING THE POTENTIAL FOR
SHOWERS AND THUNDERSTORMS. STC


&&

.AVIATION...

MAINLY VFR CONDITIONS AND NO HAZARDS TO AVIATION ARE EXPECTED
THROUGH MID DAY SUNDAY. A FEW THUNDERSTORMS ARE POSSIBLE
OVER/NEAR THE WESTERN MOUNTAINS MY MID AFTERNOON SUNDAY. STC

&&

.PRELIMINARY POINT TEMP/POPS...

    SUN     MON     TUE     WED     THU     FRI     SAT
-----------------------------------------------------------
BIL 049/077 053/080 057/085 054/086 054/075 049/074 050/073
    00/U    11/B    12/T    23/T    32/T    33/T    22/T
LVM 038/078 044/081 047/084 048/083 047/070 039/071 042/072
    01/U    11/B    22/T    23/T    33/T    22/T    23/T
HDN 049/079 051/080 056/088 054/090 056/076 052/075 050/074
    00/U    01/U    12/T    22/T    22/T    33/T    22/T
MLS 051/078 052/079 057/086 058/087 060/079 054/075 055/075
    01/U    01/U    11/U    12/T    33/T    33/T    23/T
4BQ 049/079 051/079 055/087 056/089 059/079 054/076 052/075
    01/U    11/U    12/T    22/T    22/T    33/T    22/T
BHK 047/075 048/075 055/083 057/082 060/078 053/076 053/072
    01/U    11/U    11/U    12/T    22/T    33/T    33/T
SHR 044/077 049/079 053/085 051/087 053/076 049/074 048/073
    01/U    12/T    23/T    22/T    22/T    22/T    22/T

&&

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

&&

$$
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