FXUS65 KTFX 100259
AFDTFX

SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE GREAT FALLS MT
900 PM MDT WED JUL 8 2003

CORRECTED FOR THE TIME

.DISCUSSION...WILL FRESHEN WORDING ON ZONES AND UPDATE STATE.
A VERY WEAK UPPER AIR DISTURBANCE IS MOVING THROUGH THE NORTHEASTERN
ZONES WITH SOME HIGH CLOUDS ASSOCIATED WITH IT. WINDS ARE DYING
DOWN AND WILL UPDATE TO READ LIGHT WINDS. WATER VAPOR SATELLITE
INDICATES ANOTHER VERY WEAK DISTURBANCE MOVING OVER NV WITH SOME
MID AND HI CLOUDINESS. MODELS PICK UP ON THIS FOR LATE THURSDAY INTO
EARLY FRIDAY. NOT MUCH WITH IT AT THIS TIME BUT NEED TO WATCH IT FOR
AN ISOLATED SHOWER OR THUNDERSTORM SOMEWHERE OVER THE SW ZONES.

.TONIGHT AND THURSDAY...UPPER RIDGE WAS IN THE PROCESS OF
BUILDING OVER THE PAC NW WED AFTERNOON AND WILL CONTINUE TO BUILD
AND MOVE SLOWLY E INTO THU. AIRMASS WILL CONTINUE TO BE STABLE AND
DRY THOUGH THERE MAY BE A LITTLE CLOUDINESS OVER THE FAR NRN ZONES.

.THURSDAY NIGHT THROUGH SATURDAY...UPPER RIDGE WILL STOP BUILDING
BUT CONTINUE MOVING EAST AND BE OVER THE E SLOPES OF THE ROCKY
MOUNTAINS ON SAT. AIRMASS COULD BECOME WEAKLY UNSTABLE BUT
SUBSIDENCE ASSOCIATED WITH UPPER RIDGE AND LACK OF MOISTURE SHOULD
CONTINUE TO KEEP THINGS DRY. A FIRE WEATHER CONCERN WILL BE SAT WHEN
DOWNSLOPE WINDS IN EXCESS OF 20 MPH ARE POSSIBLE. FORECAST HIGH
TEMPERATURES NEAR 90 AND DEW POINTS NEAR 40 WILL LEAD TO MINIMUM
RELATIVE HUMIDITIES BELOW 20 PCT. WILL NOT ISSUE FIRE WEATHER WATCH
THIS FAR IN ADVANCE BUT MAY BE ISSUED THU. BLANK

SUNDAY AND MONDAY...12Z GFS MODEL RUN A BIT ERRATIC...AS IT IS BEING
BACKED UP BY THE NOGAPS. GENERAL TREND STILL HOLDS...SO WILL GO WITH
PERSISTENCE. UPPER RIDGE REMAINS OVER MONTANA ON SUNDAY FOR ANOTHER
HOT (85 TO 95) AND DRY DAY FOR MOST OF THE CWA. ONLY EXCEPTION TO
DRY CONDITIONS IS THE FAR SOUTHWEST...WHERE MOISTURE WILL INCREASE
AHEAD OF APPROACHING TROUGH...FOR A SLIGHT CHANCE OF MAINLY MOUNTAIN
THUNDERSTORMS. CONTINUED HOT AND DRY CONDITIONS WILL BRING INCREASED
FIRE DANGER ON SUNDAY...BUT WINDS ARE MARGINAL AT THIS TIME.
SITUATION WILL NEED TO BE MONITORED. DIVERGING GFS AND ECMWF
SOLUTIONS FOR MONDAY A CAUSE FOR CONCERN. CURRENT FORECAST HAS A
TREND OF COMPROMISING SOLUTIONS...WHICH LOOKS GOOD FOR NOW.
INCREASING MOISTURE WITH UNSTABLE WEST/SOUTHWEST FLOW ALOFT TO BRING
A CHANCE OF SHOWERS AND THUNDERSTORMS. INCREASED CONVECTIVE ACTIVITY
ON MONDAY SHOULD ALSO COOL TEMPERATURES SOMEWHAT OVER THOSE FROM
SUNDAY.  COULSTON

TUESDAY AND WEDNESDAY...GFS FASTER THAN ECMWF WITH EASTWARD MOVEMENT
OF LOW...BUT BOTH MODELS SHOW SW FLOW ALOFT KEEPING CHANCE OF
SHOWERS AND THUNDERSTORMS TO THE REGION THROUGH MIDWEEK.


.CCF NUMBERS
GTF UB 051/087 055/089 058 04000
    UUBBB 094/058 093/053 082/051 081/051 081 00000033222
CTB BB 050/083 054/085 055 04000
    UUBBB 089/055 090/050 078/049 077/049 077 00000033222
HLN UU 054/091 057/090 060 04000
    UUBBB 094/063 096/056 085/049 084/049 084 00000033333
BZN UU 046/089 049/088 050 04000
    UUBBB 093/053 095/048 086/049 085/049 085 00000023333
WEY UU 038/080 039/080 040 04000
    UUBBB 087/050 086/045 080/044 081/044 081 00000033222
DLN UU 046/089 052/088 051 04000
    UUBBB 091/054 093/049 083/046 082/046 082 0000--22222
HVR BB 052/086 055/088 058 04000
    UUBBB 095/058 094/053 084/054 083/054 083 00000033222
LWT UB 046/081 051/084 053 04000
    UUBBB 090/053 089/048 082/049 081/049 081 00000033333

.TFX...NONE.

$$