576 
FXUS65 KBYZ 032007
AFDBIL

SOUTH CENTRAL AND SOUTHEAST MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
205 PM MDT MON JUN 3 2002

.SHORT TERM...VALID FOR TUE...WED...THU...
UPPER TROF OVER THE STATE THIS AFTERNOON...WITH 500 MB TEMPS AT -21 C
AND PLENTY OF LOW LEVEL MOISTURE AVAILABLE SHOULD SEE SCATTERED
CONVECTIVE ACTIVITY CONTINUE UNTIL AROUND MIDNIGHT TONIGHT. UPPER RIDGE
BEGINS TO BUILD IN OVERNIGHT CLEARING OUT CLOUD COVER FROM WEST TO
EAST. COULD SEE SOME AREAS OF FOG TONIGHT AS WINDS DECREASE AND
CLEARING SKIES ALLOW FOR RADIATIONAL COOLING...TRAPPING EVAPORATING
MOISTURE BENEATH SURFACE INVERSION. AS RIDGE CONTINUES TO BUILD IN
TUESDAY WE STAY IN A GENERAL NORTHWEST FLOW BUT WITH NO APPRECIABLE
DYNAMICS AND LOW LEVELS DRYING OUT IN WEST TO NORTHWEST FLOW AT THE
SURFACE...WILL CONFINE SLIGHT CHANCE POPS TO AREAS NEAR THE MOUNTAINS.
WEDNESDAY WILL BE THE WARMEST DAY OF THE SHORT TERM AS SURFACE HIGH
ANCHORS OVER NORTHEAST COLORADO BRINGING SOUTHWEST WINDS TO SOUTHERN
MONTANA. 850 TEMPS WARM INTO THE 20 TO 22C RANGE ON WEDNESDAY BRINGING
TEMPS INTO THE LOWER TO MIDDLE 80S. WITH UPPER LEVEL WINDS CONTINUING
OUT OF THE NORTHWEST LIMITING MID LEVEL WARMING...AND LOWER LEVELS
WARMING UP QUICKLY...LAPSE RATES COULD SUPPORT A HIGH BASED DRY
THUNDERSTORM OR TWO OVER THE MOUNTAINS BUT WILL NOT MENTION IN THE ZONES
AT THIS POINT WITH NO FORCING AND LIMITED MOISTURE AVAILABLE.

UPPER RIDGE AXIS BECOMES ORIENTED MORE WEST TO EAST ON THURSDAY AS
STRONG UPPER SYSTEM MOVES INTO THE WEST COAST FLATTENING UPPER FLOW.
THIS CREATES AGEOSTROPHIC CONVERGENCE OVER CENTRAL MONTANA INDUCING A
COLD FRONT ACROSS MY SOUTHERN ZONES...MOST OF THE UPPER LEVEL ENERGY
STAYS IN CANADA SO CONVECTION WILL BE TIED TO THE LOW LEVEL BOUNDARY. IT
LOOKS LIKE THERE WILL BE SUFFICIENT PACIFIC MOISTURE TO TO BRING
SCATTERED POPS ALONG MY SOUTHERN ZONES WHILE SLIGHT CHANCE WILL DO
FURTHER NORTH AWAY FROM FRONT. TEMPS WILL DROP A FEW DEGREES OFF
WEDNESDAYS HIGHS ON THURSDAY...BUT TIMING AND CLOUD COVER STILL AN ISSUE
SO WONT GO AS FAR AS AVN SUGGESTS. CHAMBERS

.LONG TERM...VALID FOR FRI...SAT...SUN...MON...
AFTER THE RIDGE TAKES A BEATING ON THURSDAY A STRONG SHORTWAVE MOVES
ALONG THE CANADIAN/MONTANA BORDER ON FRIDAY AFTERNOON. MAIN DYNAMICS
PASS TO THE NORTH OF THE AREA...BUT ENOUGH SHOULD EFFECT THE SOUTHERN
PART OF THE STATE TO OFFER GOOD MIXING AND PERIODS OF SUNSHINE TO KEEP
TEMPS FROM BEING TOO COOL. BEHIND THIS SYSTEM ON SATURDAY...ANOTHER
COOL AND UNSETTLED PATTERN SHOULD PREVAIL...THUS SCATTERED POPS AND
BELOW NORMAL TEMPS LOOK GOOD. MONDAY DOES PROMISE A DRYING OUT SO WILL
NOT HAVE POPS AND WILL WARM UP TEMPS. BORSUM


    TUE     WED     THU     FRI     SAT     SUN     MON
-----------------------------------------------------------
BIL 044/076 049/083 054/079 050/076 049/072 047/070 051/080
    42/T    20/U    03/T    23/T    33/T    33/T    00/B
LVM 041/074 046/080 052/078 050/076 049/070 047/068 051/079
    42/T    20/U    04/T    23/T    33/T    33/T    00/E
HDN 044/076 047/084 054/079 050/076 049/072 047/070 051/080
    42/T    20/U    03/T    23/T    33/T    33/T    00/B
MLS 043/074 048/085 055/078 052/071 051/070 049/068 051/074
    40/B    00/U    02/T    23/T    33/T    33/T    00/B
4BQ 043/074 048/085 056/078 052/071 051/070 049/068 051/074
    40/B    00/U    03/T    23/T    33/T    33/T    00/B
BHK 043/074 048/083 054/078 052/071 051/070 049/068 051/074
    40/B    00/U    02/T    23/T    33/T    33/T    00/B
SHR 041/074 043/084 050/081 047/075 046/069 044/067 049/079
    42/T    20/U    04/T    23/T    33/T    33/T    00/B


.BYZ...
MT...FLOOD WATCH THROUGH EARLY NEXT WEEK FOR ZONES MTZ039>040...MTZ056.
WY...NONE.