Hail in Montana, June 16, 2008

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
251 PM MDT MON JUN 16 2008

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH WEDNESDAY...
FAIRLY QUIET WEATHER IN STOCK THRU AT LEAST MOST OF THE DAY
TUESDAY THANKS TO A DEVELOPING UPPER RIDGE ACROSS MONTANA...THOUGH
BY WEDNESDAY CONDITIONS WILL BECOME MORE UNSETTLED COURTESY OF A
WEAK COLD FRONT SLIDING INTO THE REGION.

REST OF TODAY INTO TUESDAY NIGHT...AXIS OF INCREASING INSTABILITY
THIS AFTERNOON NEAR A SURFACE TROF IN CENTRAL MONTANA WILL BE THE
FOCUS FOR A FEW THUNDERSTORMS. THESE SHOULD GRADUALLY MOVE OFF THE
HIGHER TERRAIN AND AFFECT MAINLY THE SOUTHERN ZONES. RELATIVELY
DRY SUB-CLOUD LAYER COULD STILL RESULT IN SOME GUSTY WINDS WHILE
AT THE SAME TIME ALLOWING ANY SMALL HAILSTONES ALOFT TO REACH THE
SURFACE. MOST OF THIS ACTIVITY IS EXPECTED TO LOSE ITS PUNCH BY MID
EVENING. BY TUESDAY AFTERNOON THE UPPER RIDGE WILL BECOME MORE
PRONOUNCED OVER THE CWA ALL THE WHILE THE SURFACE TROF EASES INTO
THE WESTERN ZONES. 850MB TEMPS JUMPING TO AROUND +20C WILL FINALLY
ALLOW FOR SOME ABOVE NORMAL MAX TEMPS. MODELS CONTINUE TO INDICATE
DECENT AMOUNTS OF AFTERNOON INSTABILITY ACROSS THE SOUTHERN AND
WESTERN ZONES IN CONCERT WITH HIGHER DEWPOINTS...HOWEVER AVAILABLE
LIFT FOR CONVECTION APPEARS VERY SCARCE UNTIL LATE IN THE DAY WHEN
A POCKET OF HEIGHT FALLS WEARS DOWN THE RIDGE TEMPORARILY.

WEDNESDAY...EXPECT THE TAIL-END OF A WEAK COLD FRONT TO SETTLE
INTO NORTHEAST MONTANA EARLY THIS DAY. MODELS AGREE IN SLOWING
THIS FRONT DOWN JUST ENOUGH BY THE AFTERNOON TO PROMOTE BETTER
CHANCES FOR AFTERNOON PRECIPITATION OVER THE SOUTHEAST ZONES.
VARIOUS SOUNDINGS ALONG THIS FRONT INDICATE REASONABLE POTENTIAL
FOR SOME ROBUST CONVECTION ESPECIALLY GIVEN AVAILABLE LIFT AND
HIGHER DEWPOINTS. NO THREAT OF STRONG WINDS BEHIND THE COLD FRONT
AS THE TIGHTEST PRESSURE GRADIENT REMAINS IN THE CANADIAN PRAIRIES.
MCZ

.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...
NOT MANY CHANGES TO THE FORECAST FOR THE EXTENDED PERIOD. MODELS
CONTINUE WITH THE IDEA OF RIDGE OVER THE REGION THROUGH THE
PERIOD WITH UPPER LOW REMAINING OFF THE BC COAST. SOME IMPULSES
EJECTING OUT OF THE LOW BUT MODELS STILL DIFFERING SLIGHTLY ON
TIMING OF THESE FEATURES. OVERALL PATTERN SUPPORTS CHANCES OF
THUNDERSTORMS AND TEMPERATURES NEAR OR SLIGHTLY ABOVE NORMAL.
EBERT

PREVIOUS LONG TERM DISCUSSION...FRONTAL SYSTEM COULD BRING SOME
THUNDERSTORMS TO THE AREA WEDNESDAY NIGHT. OTHERWISE...THE MODELS
HAVE EASTERN MONTANA EITHER ON AN UPPER RIDGE AXIS OR IN SW FLOW
ALOFT WITH THE UPPER RIDGE IN THE DAKOTAS THE ENTIRE PERIOD. THE
RIDGE SLIDES A BIT TO THE EAST WEDNESDAY NIGHT AND THURSDAY AND
THEN REFORMS AGAIN OVER EASTERN MONTANA BY THE WEEKEND ONLY TO
SLIDE EAST AGAIN SOMETIME OVER THE WEEKEND. MODELS DIFFER ON THE
TIMING OF EACH OF THESE PHASES. THEY ALSO DIFFER ON THE TIMING OF
ANY PASSING SHORTWAVES ACROSS THE FORECAST AREA SO TIMING WHEN ANY
PRECIP MIGHT OCCUR IS DIFFICULT. TEMPERATURES WILL BE A FEW
DEGREES ABOVE NORMAL OVER THE PERIOD BUT NO HOT WEATHER APPEARS TO
BE COMING WITH THE RIDGE AT THIS TIME. PATTERN DOES LEAD TO
AFTERNOON INSTABILITY SO WILL MENTION A SLIGHT CHANCE OF
THUNDERSTORMS EACH DAY. FORRESTER

&&

.AVIATION...
AFTERNOON CUMULUS FIELD WITH BASES AT 8-10 FEET WILL PERSIST UNTIL
AROUND SUNSET. A FEW SHOWERS WITH GUSTY WINDS MAY MOVE ACROSS THE
TAF SITES THROUGH EARLY EVENING. LOOK FOR CLEAR SKIES AND LIGHT
EAST TO SOUTHEAST WINDS TONIGHT AND INTO TUESDAY MORNING. RAE

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

WEATHER.GOV/GLASGOW