000 
FXUS65 KGGW 012023
AFDGGW

NORTHEAST MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
222 PM MDT SUN JUN 1 2003

.SHORT TERM...TONIGHT THROUGH WEDNESDAY
LONGWAVE PATTERN TO UNDERGO MAJOR CHANGES DURING THE NEXT COUPLE OF 
DAYS.  MODELS IN GOOD AGREEMENT THAT AN UPPER RIDGE IS EXPECTED TO 
BUILD FROM OFF THE WEST COAST OF THE CONUS TO THE GULF OF ALASKA.  
DOWNSTREAM OVER EASTERN MT MODELS INDICATE THAT A CLOSED LOW 
DEVELOPS OVER ALBERTA AND SLIDES SOUTHEAST INTO THE NORTHERN PLAINS 
BY THE MIDDLE OF THE WEEK. A COOL AND UNSETTLED PATTERN SETTING UP 
FOR EASTERN MT. 

IN THE SHORT TERM...LATEST MSAS ANALYSIS INDICATES A SURFACE TROUGH 
STRETCHES FROM ALBERTA INTO CENTRAL MT WITH GOOD LOW LEVEL 
CONVERGENCE ALONG THE TROUGH. THIS TROUGH WILL MOVE SLOWLY EAST TO 
THE MT/ND BORDER BY MONDAY AFTERNOON. KGGW 88-D CONTINUES TO SHOW AN 
AREA OF RAIN MOVING VERY SLOWLY OFF TO THE EAST...WITH A SCATTERING 
OF SHOWERS AND THUNDERSHOWERS ACROSS OUR WESTERN ZONES. WILL KEEP IN 
A CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS THROUGH THE EVENING 
IN THE WEST. WILL WAIT TO THE LAST MINUTE AND BASED ON WHAT THE 
RADAR LOOKS LIKE PLAN ON HAVING AN AREA OF LIKELY POPS TO LINE UP 
WITH AND JUST EAST OF THE BAND OF RAIN. LOOKS LIKE THERE WILL BE A 
BREAK IN THE ACTION OVERNIGHT INTO MONDAY MORNING WHEN WE DRY 
OUT...AND THIS LINES UP WELL WITH THE THINKING OF SURROUNDING MT 
OFFICES.

ON MONDAY THE SFC TROUGH CONTINUES TO PUSH EAST AND BOTH THE ETA AND 
AVN BRING SOME SHORT WAVE ENERGY THROUGH DURING THE AFTERNOON.  A 
STRONG UPPER TROUGH ACROSS IDAHO WILL SLIDE INTO EASTERN MT DURING 
THE AFTERNOON. THE ATMOSPHERE BECOMES MARGINALLY UNSTABLE DURING THE 
AFTERNOON AND EXPECT THAT THERE WILL BE A FEW WIDELY SCATTERED 
SHOWERS AND THUNDERSTORMS.  LOOKS LIKE THE BEST CHANCE OF CONVECTION 
WILL BE ACROSS OUR EASTERN ZONES IN THE VICINITY OF THE SFC 
BOUNDARY. WILL UPDATE THE GRIDS TO INCREASE POPS ACROSS OUR EASTERN 
ZONES TOMORROW AFTERNOON AND ALSO INCLUDE THE MENTION OF THUNDER.

HEIGHTS CONTINUE TO LOWER WITH ADDITIONAL SHORT WAVE ENERGY MOVING 
THROUGH MONDAY NIGHT AND WILL CONTINUE WITH A CHANCE OF SHOWERS. ETA 
AND AVN DONT SEEM TO BE HANDLING THE TIMING OF THE INDIVIDUAL SHORT 
WAVES WELL SO WILL JUST BROADBRUSH WITH CHANCE POPS.

CLOSED UPPER LOW SLIDES SOUTHEAST TUESDAY AND THE GFS IS THE DEEPEST 
AND FURTHEST SOUTH WITH THE UPPER LOW DROPPING INTO NORTHEAST MT.  
QUITE A BIT OF SHORT WAVE ENERGY TO PUSH THROUGH THE DAY AND CURRENT 
GRIDS LOOK TO HANDLE THIS WELL WITH A CHANCE OF RAIN. 850H TEMPS ARE 
SEVERAL DEGREES COOLER ON THE AVN (DOWN TO +3C BY 00Z WED ALONG THE 
INTERNATIONAL BORDER) AND WILL LEAN TOWARDS THE AVNS COOLER 
NUMBERS. 1000-500H THICKNESS ARE PROGGED TO DROP INTO THE 540S AND 
WOULD NOT BE SURPRISED IF AREAS IN THE FAR NORTH HAVE A HARD TIME 
GETTING OUT OF THE UPPER 40S...BUT AT THIS TIME WILL JUST CONTINUE 
THE TREND AND LOWER MAXIMUM TEMPS A FEW MORE DEGREES. AS THE UPPER 
LOW MOVES OFF INTO ND WEDNESDAY WELL BE IN A VERY COOL NORTH FLOW 
WITH SCATTERED SHOWERS AND WELL BELOW NORMAL TEMPERATURES FOR EARLY 
JUNE. CB

.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
UNSETTLED PATTERN SHOULD HOLD AT LEAST INTO AT LEAST THURSDAY NIGHT. 
MEDIUM RANGE MODELS ARE IN AGREEMENT WITH HOLDING A TROF PATTERN 
OVER THE CONUS. BY THE END OF THE WEEK...SOME RIDGING OCCURS OVER 
THE EASTERN PORTION OF THE COUNTRY. THIS WOULD PROBABLY HOLD THE 
TROF IN OVER MT QUITE WELL. NEW GFS RUN THIS MORNING SHOWING 
CONTINUED SHORTWAVE ACTIVITY TO MOVE INTO THE AREA THROUGH FRIDAY. 
ALSO TEMPS FRIDAY AT 12Z DOWN AROUND +2 AT 850 MB...QUITE A BIT 
COOLER THAT WHAT THE 00Z RUN HAD. WILL HOLD OFF ON ANY CHANGES AS 
THINGS COULD CHANGE. HOWEVER...WILL PASS ON TO LATER SHIFTS TO RAISE 
POPS/LOWER TEMPS IF THESE MODEL SOLUTIONS CONTINUE. AIRMASS SHOULD 
MODIFY A BIT NEXT WEEKEND AS HEIGHTS GRADUALLY RISE.  JAMBA 

KGGW ERE 048/069 044/059 041/061 92423433
     WEBB 042/068 043/069 047/074 046/074 7633000000
KGDV TRR 048/072 044/064 040/063 92644433
     WBBB 042/066 043/066 047/073 044/074 7633300000

.GGW...NONE.

$$