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000
FXUS65 KTFX 230417
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1017 PM MDT FRI MAY 22 2015

.UPDATE...
HAVE MADE SOME ADJUSTMENTS TO POPS TONIGHT BASED ON LATEST TRENDS
IN SATELLITE AND RADAR DATA. SCATTERED SHORT-LIVED SHOWERS AND
ISOLATED THUNDERSTORMS HAVE DEVELOPED OVER CASCADE...CHOUTEAU AND
SOUTHERN BLAINE COUNTIES WHERE POPS WERE INCREASED THIS EVENING AS
THIS ACTIVITY CONTINUES TO PUSH SLOWLY WESTWARD. SHOULD SEE A
GENERAL DISSIPATING TREND AFTER 04Z...BUT SOME SHOWERS COULD
LINGER THROUGH THE NIGHT ACROSS JUDITH BASIN...FERGUS AND BLAINE
COUNTIES AS A WEAK DISTURBANCE ROTATES AROUND THE BROAD UPPER LOW
CENTERED OVER THE GREAT BASIN INTO EASTERN PORTIONS OF CENTRAL MT
LATE TONIGHT. HOENISCH

&&

.AVIATION...

UPDATED 0416Z.

CENTRAL AND SOUTHWEST MONTANA WILL REMAIN UNDER THE INFLUENCE OF A
WEAK UPPER LEVEL LOW PRESSURE TROF THROUGH SATURDAY. THE AIRMASS
WILL REMAIN RATHER MOIST AT MID-LEVELS ACROSS SOUTHWEST MONTANA
TONIGHT. THIS MOISTURE WILL CREEP FARTHER NORTH SATURDAY AND PUSH
INTO THE HILINE BY AFTERNOON. ISOLATED THUNDERSTORMS WILL END THIS
EVENING BUT A CHANCE OF THUNDERSTORMS WILL DEVELOP AGAIN SATURDAY
AFTERNOON. LOCAL MVFR CIGS ARE POSSIBLE NEAR SHOWERS AND
THUNDERSTORMS BUT ELSEWHERE VFR CONDITIONS WILL PREVAIL THROUGH THE
NEXT 24 HOURS.

&&

.PREV DISCUSSION...
/ISSUED 528 PM MDT FRI MAY 22 2015/
CURRENT RADAR/SATELLITE IMAGERY SHOWING SCATTERED SHOWERS AND A FEW
SMALL THUNDERSTORMS DEVELOPING MAINLY FROM THE LITTLE BELT AND SNOWY
MTNS SOUTH TO THE MT/ID BORDER.  EXPECT PRECIPITATION COVERAGE TO
INCREASE OVER THE SOUTHWEST COUNTIES AND EXTEND INTO PARTS OF
CASCADE/CHOUTEAU/FERGUS/JUDITH BASIN COUNTIES BY LATE AFTN AS
ADDITIONAL MOISTURE ARRIVES FROM IDAHO/WYOMING.  MOISTURE PUSH IS
DRIVEN BY A SLOW-MOVING UPPER-LEVEL LOW PRESSURE AREA PRESENTLY
CENTERED AT THE CA/NV/AZ BORDER.  FORECAST MODELS REMAIN IN VERY
GOOD AGREEMENT THAT THE LOW WILL TRACK GRADUALLY TO THE NORTHEAST
THROUGH THE GREAT BASIN OVER THE WEEKEND, REACHING EASTERN WYOMING
BY MIDDAY SUNDAY.  AS IT MOVES, EAST-SOUTHEAST WINDS ON THE
FRONTSIDE OF THE LOW`S CIRCULATION WILL BRING BOTH PACIFIC AND SOME
GULF OF MEXICO MOISTURE INTO MT, PRODUCING SCATTERED SHOWERS AND
THUNDERSTORMS EACH AFTERNOON AND EVENING THROUGH SUNDAY. NO STRONG
OR SEVERE STORMS ARE EXPECTED AT THIS TIME, AS INSTABILITY AND WIND
SHEAR PARAMETERS ARE FORECAST TO BE WEAK FOR THE NEXT COUPLE DAYS.
CONVECTIVE ACTIVITY WILL DISSIPATE OVER MOST OF THE FORECAST AREA
EACH EVENING NEAR/AFTER SUNSET.

LATEST MODELS ARE ALSO INDICATING A BETTER CHANCE OF SHORT-TERM DRY
CONDITIONS ON MONDAY AS OUR REGION WILL BE BETWEEN THE EXITING
WEEKEND WEATHER SYSTEM AND THE NEXT SHORTWAVE TROF MOVING INTO THE
PACIFIC NORTHWEST. ISOLATED SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE ALONG THE ROCKY MTN FRONT AND PARTS OF SOUTHWEST MT MON
AFTN/EVE AS THE TROF TAPS INTO RESIDUAL MOISTURE OVER WESTERN MT,
WHILE LOCATIONS GENERALLY ALONG/EAST OF THE INTERSTATE 15 CORRIDOR
REMAIN PRECIP FREE.
WARANAUSKAS

MONDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT
IN A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO
MIDWEEK. THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED
MONDAY NIGHT THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH
THEIR FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER
LOW NEAR VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS
IT MOVES INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER
LOW SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON
FRIDAY. DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR
PRECIPITATION FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM
TUESDAY ON OF SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS
THE CANADIAN BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED
THUNDERSTORMS DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO
NOT ANTICIPATE ANY SEVERE STORMS AT THIS TIME.
BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  47  64  43  65 /  50  40  20  20
CTB  42  67  38  67 /  10  20  10  10
HLN  48  64  45  67 /  40  70  40  20
BZN  42  61  41  62 /  20  60  40  40
WEY  34  57  33  57 /  60  60  40  30
DLN  44  62  41  63 /  30  50  30  30
HVR  42  70  41  71 /  20  20  10  20
LWT  45  61  42  61 /  50  50  20  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



  [top]

000
FXUS65 KBYZ 230314
AFDBYZ

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
914 PM MDT FRI MAY 22 2015

.UPDATE...
DISORGANIZED LOW-TOPPED CONVECTION HAS BEEN OCCURRING OVER THE
CENTRAL AND WESTERN ZONES THIS EVENING. THE CONVECTION WAS THE
RESULT OF A WEAK WAVE MOVING W IN THE WEAK FLOW ALOFT COMBINED
WITH UPSLOPE FLOW AND DAYTIME HEATING. PRECIPITABLE WATERS WERE
ALSO ON THE ORDER OF /0.6/ TO /0.8/ INCHES OVER THE AREA DUE TO
MOIST SE FLOW. MESOANALYSIS SHOWED THAT CAPES WERE DECREASING OVER
THE AREA OVER THE LAST FEW HOURS...BUT THE MID-LEVEL LAPSE RATES
WERE AROUND 6.5 DEG C/KM...SUPPORTING CONTINUED LIGHTNING STRIKES.

WEAK ENERGY WILL REMAIN OVER THE AREA TONIGHT ALONG WITH HIGH
PRECIPITABLE WATERS. UPSLOPE FLOW WILL CONTINUE BUT STABILITY WILL
INCREASE DUE TO LOSS OF HEATING. THUS ADJUSTED POPS LOWER THROUGH
06Z BASED ON LATEST RADAR IMAGERY...AND LOWERED THEM A BIT
OVERNIGHT AS WELL. LEFT THUNDER OUT OF THE FORECAST OVERNIGHT.
MODELS WERE INDICATING POSSIBLE LOW CEILINGS OR FOG OVERNIGHT.
GIVEN THE LARGE AMOUNT OF CLOUD COVER ALREADY OVER THE
AREA...FOG DOES NOT SEEM LIKELY. HOWEVER...THERE COULD BE
SCATTERED TO BROKEN LOW CLOUDS ADVECTING INTO THE AREA
OVERNIGHT. INCREASED WIND SPEEDS OVER KLVM AND KSHR WHERE THE E TO
SE WINDS HAVE BEEN GUSTY THIS EVENING.

BROAD TROUGH OVER THE WESTERN U.S. WAS FORECAST TO CONSOLIDATE
INTO A BROAD UPPER LOW FROM MT TO THE FOUR CORNERS REGION ON SAT.
WITH PLENTY OF WAVES AND MOISTURE OVER THE AREA...EXPECT MORE
SHOWERS AND THUNDERSTORMS...WHICH WILL CONTINUE THROUGH SUN AS THE
SYSTEM WILL REMAIN ALMOST STATIONARY. ARTHUR

&&

.SHORT TERM...VALID FOR SAT AND SUN...

AN UPPER LOW MOVING NORTHEAST OUT OF COLORADO THIS AFTERNOON IS
RESULTING IN AREAS OF RAIN ACROSS WESTERN NEBRASKA AND SOUTHEAST
WYOMING. SOME OF THIS PRECIP IS SLOWLY SHIFTING NORTH RESULTING IN
ISOLATED TO SCATTERED SHOWERS ACROSS NORTHERN WYOMING INTO
SOUTHERN/SOUTHEASTERN MONTANA. THERE IS ANOTHER UPPER LOW THAT IS
CURRENTLY MOVING OUT OF SOUTHERN CALIFORNIA INTO THE FOUR CORNERS
AREA. THESE TWO LOWS ARE WRAPPING MOISTURE WEST AND NORTH ACROSS
THE GREAT BASIN AREA. LIGHTING DATA IS SHOWING THUNDERSTORMS
POPPING UP ALL ACROSS THE WEST EAST OF THE ROCKIES. WATER VAPOR
IMAGERY ALONG WITH THE LIGHTING DATA LOOK TO BE WHAT WE WOULD
TYPICALLY SEE DURING THE MONSOON SEASON OF LATE JULY/EARLY AUGUST.

THESE LOWS WILL SLOWLY MOVE EAST AND NORTHEAST THROUGH THE
WEEKEND WITH PIECES OF ENERGY GETTING EJECTED ACROSS OUR AREA. AS
A RESULT...WILL KEEP A CHANCE FOR SHOWERS AND ISOLATED
THUNDERSTORMS IN THE FORECAST THROUGH THE WEEKEND. AS THE UPPER
LOW OVER THE FOUR CORNERS REGION MOVES INTO THE WESTERN HIGH
PLAINS SUNDAY INTO SUNDAY NIGHT...IT WILL WRAP MOISTURE AROUND THE
BACK SIDE OF IT ACROSS SOUTHEAST MONTANA BRINGING THE LIKELIHOOD OF
NUMEROUS SHOWERS OR POSSIBLY A LIGHT STEADY RAIN. AS A RESULT...I
INCREASED POPS TO LIKELY FOR OUR FAR SOUTHEAST COUNTIES LATE
SATURDAY NIGHT INTO EARLY MONDAY MORNING.

ELSEWHERE ACROSS THE FORECAST AREA...SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS CAN BE EXPECTED THROUGH THE WEEKEND. GIVEN
THE LIGHT WINDS ALOFT/LITTLE SHEAR...THUNDERSTORMS ARE NOT
EXPECTED TO BE SEVERE OR EVEN STRONG BUT THEY MAY PRODUCE SOME
BRIEF HEAVY RAIN. WITH THE EXCEPTION OF FAR SOUTHEAST MONTANA
SUNDAY...THE WEEKEND FOR THE MAJORITY OF OUR AREA IS NOT EXPECTED
TO BE A WASHOUT. TEMPERATURES WILL BE BELOW NORMAL IN THE LOWER
60S FOR MOST AREAS BUT NOT AS COOL AS THE PAST COUPLE OF WEEKENDS.
HOOLEY

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

A BROAD TROUGH WILL BE OVER THE EASTERN HALF OF THE NORTHERN AND
CENTRAL ROCKIES MONDAY INTO TUESDAY. THE FLOW ALOFT WILL BE WEAK
AS THE MAJORITY OF THE JET ENERGY WILL BE TO OUR NORTH AND SOUTH
OF OUR FORECAST AREA. THERE WILL BE ENOUGH INSTABILITY AROUND TO
WARRANT A CHANCE FOR A SHOWER OR THUNDERSTORM MONDAY AND TUESDAY.
850MB TEMPERATURES WILL BEGIN TO WARM FROM WEST TO EAST MONDAY AND
WITH READINGS AROUND 15-18C SPREADING EAST ACROSS THE ENTIRE AREA
TUESDAY RESULTING IN TEMPERATURES WARMING TO NORMAL TO SLIGHTLY
ABOVE NORMAL VALUES.

MODELS BRING AN UPPER LOW OVER THE PACIFIC NORTHWEST EASTWARD
ACROSS MONTANA WEDNESDAY INTO THURSDAY RESULTING IN INCREASING
CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS. A COLD FRONT IS
PROGGED TO DROP SOUTH ACROSS THE FORECAST AREA THURSDAY NIGHT INTO
FRIDAY KEEPING SHOWER AND THUNDERSTORM CHANCES IN THE FORECAST.
TEMPERATURES LOOK TO BE AROUND NORMAL THROUGH THE PERIOD UNTIL
FRIDAY WHEN READINGS WILL COOL SLIGHTLY BEHIND THE COLD FRONT.
HOOLEY
&&

.AVIATION...

ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL PERSIST INTO
THE LATE EVENING HOURS TONIGHT. LOCAL MVFR OR LOWER CONDITIONS CAN
BE EXPECTED NEAR THIS ACTIVITY WITH BRIEF HEAVY RAINFALL. RESIDUAL
VFR CLOUD COVER WILL PERSIST ONCE CONVECTION DISSIPATES. THERE IS
SOME INDICATION SOME MVFR CEILINGS COULD DEVELOP BETWEEN 11Z-15Z
TOMORROW MORNING AT KSHR...KLVM AND KBIL. CONFIDENCE AT THIS TIME
IS NOT VERY HIGH THIS WILL OCCUR OR BE WIDESPREAD. LOOK FOR MORE
SCATTERED SHOWERS TOMORROW. BT

&&

.PRELIMINARY POINT TEMP/POPS...

    SAT     SUN     MON     TUE     WED     THU     FRI
-----------------------------------------------------------
BIL 046/063 045/060 045/070 047/072 049/071 050/071 048/066
    23/T    23/T    32/T    23/T    33/T    33/T    33/T
LVM 045/061 041/061 039/067 043/068 044/066 045/069 043/065
    56/T    33/T    33/T    34/T    44/T    43/T    33/T
HDN 045/065 046/061 045/071 046/074 049/074 049/074 048/069
    23/T    33/T    32/T    23/T    33/T    33/T    33/T
MLS 047/064 045/062 047/067 046/073 050/072 050/071 049/067
    13/T    44/T    44/T    42/T    23/T    33/T    33/T
4BQ 043/059 046/058 046/065 045/072 049/071 049/070 048/068
    16/T    67/T    43/T    33/T    33/T    33/T    33/T
BHK 043/058 045/060 045/065 043/069 047/070 048/069 046/066
    16/T    67/T    66/T    63/T    33/T    33/T    33/T
SHR 045/059 043/058 042/065 042/070 046/070 046/069 045/068
    25/T    46/T    33/T    34/T    43/T    33/T    33/T

&&

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

&&

$$
WEATHER.GOV/BILLINGS



000
FXUS65 KBYZ 230314
AFDBYZ

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
914 PM MDT FRI MAY 22 2015

.UPDATE...
DISORGANIZED LOW-TOPPED CONVECTION HAS BEEN OCCURRING OVER THE
CENTRAL AND WESTERN ZONES THIS EVENING. THE CONVECTION WAS THE
RESULT OF A WEAK WAVE MOVING W IN THE WEAK FLOW ALOFT COMBINED
WITH UPSLOPE FLOW AND DAYTIME HEATING. PRECIPITABLE WATERS WERE
ALSO ON THE ORDER OF /0.6/ TO /0.8/ INCHES OVER THE AREA DUE TO
MOIST SE FLOW. MESOANALYSIS SHOWED THAT CAPES WERE DECREASING OVER
THE AREA OVER THE LAST FEW HOURS...BUT THE MID-LEVEL LAPSE RATES
WERE AROUND 6.5 DEG C/KM...SUPPORTING CONTINUED LIGHTNING STRIKES.

WEAK ENERGY WILL REMAIN OVER THE AREA TONIGHT ALONG WITH HIGH
PRECIPITABLE WATERS. UPSLOPE FLOW WILL CONTINUE BUT STABILITY WILL
INCREASE DUE TO LOSS OF HEATING. THUS ADJUSTED POPS LOWER THROUGH
06Z BASED ON LATEST RADAR IMAGERY...AND LOWERED THEM A BIT
OVERNIGHT AS WELL. LEFT THUNDER OUT OF THE FORECAST OVERNIGHT.
MODELS WERE INDICATING POSSIBLE LOW CEILINGS OR FOG OVERNIGHT.
GIVEN THE LARGE AMOUNT OF CLOUD COVER ALREADY OVER THE
AREA...FOG DOES NOT SEEM LIKELY. HOWEVER...THERE COULD BE
SCATTERED TO BROKEN LOW CLOUDS ADVECTING INTO THE AREA
OVERNIGHT. INCREASED WIND SPEEDS OVER KLVM AND KSHR WHERE THE E TO
SE WINDS HAVE BEEN GUSTY THIS EVENING.

BROAD TROUGH OVER THE WESTERN U.S. WAS FORECAST TO CONSOLIDATE
INTO A BROAD UPPER LOW FROM MT TO THE FOUR CORNERS REGION ON SAT.
WITH PLENTY OF WAVES AND MOISTURE OVER THE AREA...EXPECT MORE
SHOWERS AND THUNDERSTORMS...WHICH WILL CONTINUE THROUGH SUN AS THE
SYSTEM WILL REMAIN ALMOST STATIONARY. ARTHUR

&&

.SHORT TERM...VALID FOR SAT AND SUN...

AN UPPER LOW MOVING NORTHEAST OUT OF COLORADO THIS AFTERNOON IS
RESULTING IN AREAS OF RAIN ACROSS WESTERN NEBRASKA AND SOUTHEAST
WYOMING. SOME OF THIS PRECIP IS SLOWLY SHIFTING NORTH RESULTING IN
ISOLATED TO SCATTERED SHOWERS ACROSS NORTHERN WYOMING INTO
SOUTHERN/SOUTHEASTERN MONTANA. THERE IS ANOTHER UPPER LOW THAT IS
CURRENTLY MOVING OUT OF SOUTHERN CALIFORNIA INTO THE FOUR CORNERS
AREA. THESE TWO LOWS ARE WRAPPING MOISTURE WEST AND NORTH ACROSS
THE GREAT BASIN AREA. LIGHTING DATA IS SHOWING THUNDERSTORMS
POPPING UP ALL ACROSS THE WEST EAST OF THE ROCKIES. WATER VAPOR
IMAGERY ALONG WITH THE LIGHTING DATA LOOK TO BE WHAT WE WOULD
TYPICALLY SEE DURING THE MONSOON SEASON OF LATE JULY/EARLY AUGUST.

THESE LOWS WILL SLOWLY MOVE EAST AND NORTHEAST THROUGH THE
WEEKEND WITH PIECES OF ENERGY GETTING EJECTED ACROSS OUR AREA. AS
A RESULT...WILL KEEP A CHANCE FOR SHOWERS AND ISOLATED
THUNDERSTORMS IN THE FORECAST THROUGH THE WEEKEND. AS THE UPPER
LOW OVER THE FOUR CORNERS REGION MOVES INTO THE WESTERN HIGH
PLAINS SUNDAY INTO SUNDAY NIGHT...IT WILL WRAP MOISTURE AROUND THE
BACK SIDE OF IT ACROSS SOUTHEAST MONTANA BRINGING THE LIKELIHOOD OF
NUMEROUS SHOWERS OR POSSIBLY A LIGHT STEADY RAIN. AS A RESULT...I
INCREASED POPS TO LIKELY FOR OUR FAR SOUTHEAST COUNTIES LATE
SATURDAY NIGHT INTO EARLY MONDAY MORNING.

ELSEWHERE ACROSS THE FORECAST AREA...SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS CAN BE EXPECTED THROUGH THE WEEKEND. GIVEN
THE LIGHT WINDS ALOFT/LITTLE SHEAR...THUNDERSTORMS ARE NOT
EXPECTED TO BE SEVERE OR EVEN STRONG BUT THEY MAY PRODUCE SOME
BRIEF HEAVY RAIN. WITH THE EXCEPTION OF FAR SOUTHEAST MONTANA
SUNDAY...THE WEEKEND FOR THE MAJORITY OF OUR AREA IS NOT EXPECTED
TO BE A WASHOUT. TEMPERATURES WILL BE BELOW NORMAL IN THE LOWER
60S FOR MOST AREAS BUT NOT AS COOL AS THE PAST COUPLE OF WEEKENDS.
HOOLEY

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

A BROAD TROUGH WILL BE OVER THE EASTERN HALF OF THE NORTHERN AND
CENTRAL ROCKIES MONDAY INTO TUESDAY. THE FLOW ALOFT WILL BE WEAK
AS THE MAJORITY OF THE JET ENERGY WILL BE TO OUR NORTH AND SOUTH
OF OUR FORECAST AREA. THERE WILL BE ENOUGH INSTABILITY AROUND TO
WARRANT A CHANCE FOR A SHOWER OR THUNDERSTORM MONDAY AND TUESDAY.
850MB TEMPERATURES WILL BEGIN TO WARM FROM WEST TO EAST MONDAY AND
WITH READINGS AROUND 15-18C SPREADING EAST ACROSS THE ENTIRE AREA
TUESDAY RESULTING IN TEMPERATURES WARMING TO NORMAL TO SLIGHTLY
ABOVE NORMAL VALUES.

MODELS BRING AN UPPER LOW OVER THE PACIFIC NORTHWEST EASTWARD
ACROSS MONTANA WEDNESDAY INTO THURSDAY RESULTING IN INCREASING
CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS. A COLD FRONT IS
PROGGED TO DROP SOUTH ACROSS THE FORECAST AREA THURSDAY NIGHT INTO
FRIDAY KEEPING SHOWER AND THUNDERSTORM CHANCES IN THE FORECAST.
TEMPERATURES LOOK TO BE AROUND NORMAL THROUGH THE PERIOD UNTIL
FRIDAY WHEN READINGS WILL COOL SLIGHTLY BEHIND THE COLD FRONT.
HOOLEY
&&

.AVIATION...

ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL PERSIST INTO
THE LATE EVENING HOURS TONIGHT. LOCAL MVFR OR LOWER CONDITIONS CAN
BE EXPECTED NEAR THIS ACTIVITY WITH BRIEF HEAVY RAINFALL. RESIDUAL
VFR CLOUD COVER WILL PERSIST ONCE CONVECTION DISSIPATES. THERE IS
SOME INDICATION SOME MVFR CEILINGS COULD DEVELOP BETWEEN 11Z-15Z
TOMORROW MORNING AT KSHR...KLVM AND KBIL. CONFIDENCE AT THIS TIME
IS NOT VERY HIGH THIS WILL OCCUR OR BE WIDESPREAD. LOOK FOR MORE
SCATTERED SHOWERS TOMORROW. BT

&&

.PRELIMINARY POINT TEMP/POPS...

    SAT     SUN     MON     TUE     WED     THU     FRI
-----------------------------------------------------------
BIL 046/063 045/060 045/070 047/072 049/071 050/071 048/066
    23/T    23/T    32/T    23/T    33/T    33/T    33/T
LVM 045/061 041/061 039/067 043/068 044/066 045/069 043/065
    56/T    33/T    33/T    34/T    44/T    43/T    33/T
HDN 045/065 046/061 045/071 046/074 049/074 049/074 048/069
    23/T    33/T    32/T    23/T    33/T    33/T    33/T
MLS 047/064 045/062 047/067 046/073 050/072 050/071 049/067
    13/T    44/T    44/T    42/T    23/T    33/T    33/T
4BQ 043/059 046/058 046/065 045/072 049/071 049/070 048/068
    16/T    67/T    43/T    33/T    33/T    33/T    33/T
BHK 043/058 045/060 045/065 043/069 047/070 048/069 046/066
    16/T    67/T    66/T    63/T    33/T    33/T    33/T
SHR 045/059 043/058 042/065 042/070 046/070 046/069 045/068
    25/T    46/T    33/T    34/T    43/T    33/T    33/T

&&

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

&&

$$
WEATHER.GOV/BILLINGS




000
FXUS65 KTFX 230140
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
740 PM MDT FRI MAY 22 2015

.UPDATE...
HAVE MADE SOME ADJUSTMENTS TO POPS TONIGHT BASED ON LATEST TRENDS
IN SATELLITE AND RADAR DATA. SCATTERED SHORT-LIVED SHOWERS AND
ISOLATED THUNDERSTORMS HAVE DEVELOPED OVER CASCADE...CHOUTEAU AND
SOUTHERN BLAINE COUNTIES WHERE POPS WERE INCREASED THIS EVENING AS
THIS ACTIVITY CONTINUES TO PUSH SLOWLY WESTWARD. SHOULD SEE A
GENERAL DISSIPATING TREND AFTER 04Z...BUT SOME SHOWERS COULD
LINGER THROUGH THE NIGHT ACROSS JUDITH BASIN...FERGUS AND BLAINE
COUNTIES AS A WEAK DISTURBANCE ROTATES AROUND THE BROAD UPPER LOW
CENTERED OVER THE GREAT BASIN INTO EASTERN PORTIONS OF CENTRAL MT
LATE TONIGHT. HOENISCH

&&

.AVIATION...

UPDATED 2326Z.

CENTRAL AND SOUTHWEST MONTANA WILL REMAIN UNDER THE INFLUENCE OF A
WEAK UPPER LEVEL LOW PRESSURE TROF THROUGH SATURDAY. THE AIRMASS
WILL REMAIN RATHER MOIST AT MID-LEVELS ACROSS SOUTHWEST MONTANA
TONIGHT. THIS MOISTURE WILL CREEP FARTHER NORTH SATURDAY AND PUSH
INTO THE HILINE BY AFTERNOON. ISOLATED THUNDERSTORMS WILL END THIS
EVENING BUT A CHANCE OF THUNDERSTORMS WILL DEVELOP AGAIN SATURDAY
AFTERNOON. LOCAL MVFR CIGS ARE POSSIBLE NEAR SHOWERS AND
THUNDERSTORMS BUT ELSEWHERE VFR CONDITIONS WILL PREVAIL THROUGH THE
NEXT 24 HOURS.

&&

.PREV DISCUSSION...
/ISSUED 528 PM MDT FRI MAY 22 2015/
CURRENT RADAR/SATELLITE IMAGERY SHOWING SCATTERED SHOWERS AND A FEW
SMALL THUNDERSTORMS DEVELOPING MAINLY FROM THE LITTLE BELT AND SNOWY
MTNS SOUTH TO THE MT/ID BORDER.  EXPECT PRECIPITATION COVERAGE TO
INCREASE OVER THE SOUTHWEST COUNTIES AND EXTEND INTO PARTS OF
CASCADE/CHOUTEAU/FERGUS/JUDITH BASIN COUNTIES BY LATE AFTN AS
ADDITIONAL MOISTURE ARRIVES FROM IDAHO/WYOMING.  MOISTURE PUSH IS
DRIVEN BY A SLOW-MOVING UPPER-LEVEL LOW PRESSURE AREA PRESENTLY
CENTERED AT THE CA/NV/AZ BORDER.  FORECAST MODELS REMAIN IN VERY
GOOD AGREEMENT THAT THE LOW WILL TRACK GRADUALLY TO THE NORTHEAST
THROUGH THE GREAT BASIN OVER THE WEEKEND, REACHING EASTERN WYOMING
BY MIDDAY SUNDAY.  AS IT MOVES, EAST-SOUTHEAST WINDS ON THE
FRONTSIDE OF THE LOW`S CIRCULATION WILL BRING BOTH PACIFIC AND SOME
GULF OF MEXICO MOISTURE INTO MT, PRODUCING SCATTERED SHOWERS AND
THUNDERSTORMS EACH AFTERNOON AND EVENING THROUGH SUNDAY. NO STRONG
OR SEVERE STORMS ARE EXPECTED AT THIS TIME, AS INSTABILITY AND WIND
SHEAR PARAMETERS ARE FORECAST TO BE WEAK FOR THE NEXT COUPLE DAYS.
CONVECTIVE ACTIVITY WILL DISSIPATE OVER MOST OF THE FORECAST AREA
EACH EVENING NEAR/AFTER SUNSET.

LATEST MODELS ARE ALSO INDICATING A BETTER CHANCE OF SHORT-TERM DRY
CONDITIONS ON MONDAY AS OUR REGION WILL BE BETWEEN THE EXITING
WEEKEND WEATHER SYSTEM AND THE NEXT SHORTWAVE TROF MOVING INTO THE
PACIFIC NORTHWEST. ISOLATED SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE ALONG THE ROCKY MTN FRONT AND PARTS OF SOUTHWEST MT MON
AFTN/EVE AS THE TROF TAPS INTO RESIDUAL MOISTURE OVER WESTERN MT,
WHILE LOCATIONS GENERALLY ALONG/EAST OF THE INTERSTATE 15 CORRIDOR
REMAIN PRECIP FREE.
WARANAUSKAS

MONDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT
IN A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO
MIDWEEK. THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED
MONDAY NIGHT THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH
THEIR FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER
LOW NEAR VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS
IT MOVES INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER
LOW SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON
FRIDAY. DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR
PRECIPITATION FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM
TUESDAY ON OF SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS
THE CANADIAN BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED
THUNDERSTORMS DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO
NOT ANTICIPATE ANY SEVERE STORMS AT THIS TIME.
BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  47  64  43  65 /  50  40  20  20
CTB  42  67  38  67 /  10  20  10  10
HLN  48  64  45  67 /  40  70  40  20
BZN  42  61  41  62 /  20  60  40  40
WEY  34  57  33  57 /  60  60  40  30
DLN  44  62  41  63 /  30  50  30  30
HVR  42  70  41  71 /  20  20  10  20
LWT  45  61  42  61 /  50  50  20  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS




000
FXUS65 KTFX 230140
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
740 PM MDT FRI MAY 22 2015

.UPDATE...
HAVE MADE SOME ADJUSTMENTS TO POPS TONIGHT BASED ON LATEST TRENDS
IN SATELLITE AND RADAR DATA. SCATTERED SHORT-LIVED SHOWERS AND
ISOLATED THUNDERSTORMS HAVE DEVELOPED OVER CASCADE...CHOUTEAU AND
SOUTHERN BLAINE COUNTIES WHERE POPS WERE INCREASED THIS EVENING AS
THIS ACTIVITY CONTINUES TO PUSH SLOWLY WESTWARD. SHOULD SEE A
GENERAL DISSIPATING TREND AFTER 04Z...BUT SOME SHOWERS COULD
LINGER THROUGH THE NIGHT ACROSS JUDITH BASIN...FERGUS AND BLAINE
COUNTIES AS A WEAK DISTURBANCE ROTATES AROUND THE BROAD UPPER LOW
CENTERED OVER THE GREAT BASIN INTO EASTERN PORTIONS OF CENTRAL MT
LATE TONIGHT. HOENISCH

&&

.AVIATION...

UPDATED 2326Z.

CENTRAL AND SOUTHWEST MONTANA WILL REMAIN UNDER THE INFLUENCE OF A
WEAK UPPER LEVEL LOW PRESSURE TROF THROUGH SATURDAY. THE AIRMASS
WILL REMAIN RATHER MOIST AT MID-LEVELS ACROSS SOUTHWEST MONTANA
TONIGHT. THIS MOISTURE WILL CREEP FARTHER NORTH SATURDAY AND PUSH
INTO THE HILINE BY AFTERNOON. ISOLATED THUNDERSTORMS WILL END THIS
EVENING BUT A CHANCE OF THUNDERSTORMS WILL DEVELOP AGAIN SATURDAY
AFTERNOON. LOCAL MVFR CIGS ARE POSSIBLE NEAR SHOWERS AND
THUNDERSTORMS BUT ELSEWHERE VFR CONDITIONS WILL PREVAIL THROUGH THE
NEXT 24 HOURS.

&&

.PREV DISCUSSION...
/ISSUED 528 PM MDT FRI MAY 22 2015/
CURRENT RADAR/SATELLITE IMAGERY SHOWING SCATTERED SHOWERS AND A FEW
SMALL THUNDERSTORMS DEVELOPING MAINLY FROM THE LITTLE BELT AND SNOWY
MTNS SOUTH TO THE MT/ID BORDER.  EXPECT PRECIPITATION COVERAGE TO
INCREASE OVER THE SOUTHWEST COUNTIES AND EXTEND INTO PARTS OF
CASCADE/CHOUTEAU/FERGUS/JUDITH BASIN COUNTIES BY LATE AFTN AS
ADDITIONAL MOISTURE ARRIVES FROM IDAHO/WYOMING.  MOISTURE PUSH IS
DRIVEN BY A SLOW-MOVING UPPER-LEVEL LOW PRESSURE AREA PRESENTLY
CENTERED AT THE CA/NV/AZ BORDER.  FORECAST MODELS REMAIN IN VERY
GOOD AGREEMENT THAT THE LOW WILL TRACK GRADUALLY TO THE NORTHEAST
THROUGH THE GREAT BASIN OVER THE WEEKEND, REACHING EASTERN WYOMING
BY MIDDAY SUNDAY.  AS IT MOVES, EAST-SOUTHEAST WINDS ON THE
FRONTSIDE OF THE LOW`S CIRCULATION WILL BRING BOTH PACIFIC AND SOME
GULF OF MEXICO MOISTURE INTO MT, PRODUCING SCATTERED SHOWERS AND
THUNDERSTORMS EACH AFTERNOON AND EVENING THROUGH SUNDAY. NO STRONG
OR SEVERE STORMS ARE EXPECTED AT THIS TIME, AS INSTABILITY AND WIND
SHEAR PARAMETERS ARE FORECAST TO BE WEAK FOR THE NEXT COUPLE DAYS.
CONVECTIVE ACTIVITY WILL DISSIPATE OVER MOST OF THE FORECAST AREA
EACH EVENING NEAR/AFTER SUNSET.

LATEST MODELS ARE ALSO INDICATING A BETTER CHANCE OF SHORT-TERM DRY
CONDITIONS ON MONDAY AS OUR REGION WILL BE BETWEEN THE EXITING
WEEKEND WEATHER SYSTEM AND THE NEXT SHORTWAVE TROF MOVING INTO THE
PACIFIC NORTHWEST. ISOLATED SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE ALONG THE ROCKY MTN FRONT AND PARTS OF SOUTHWEST MT MON
AFTN/EVE AS THE TROF TAPS INTO RESIDUAL MOISTURE OVER WESTERN MT,
WHILE LOCATIONS GENERALLY ALONG/EAST OF THE INTERSTATE 15 CORRIDOR
REMAIN PRECIP FREE.
WARANAUSKAS

MONDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT
IN A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO
MIDWEEK. THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED
MONDAY NIGHT THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH
THEIR FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER
LOW NEAR VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS
IT MOVES INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER
LOW SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON
FRIDAY. DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR
PRECIPITATION FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM
TUESDAY ON OF SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS
THE CANADIAN BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED
THUNDERSTORMS DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO
NOT ANTICIPATE ANY SEVERE STORMS AT THIS TIME.
BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  47  64  43  65 /  50  40  20  20
CTB  42  67  38  67 /  10  20  10  10
HLN  48  64  45  67 /  40  70  40  20
BZN  42  61  41  62 /  20  60  40  40
WEY  34  57  33  57 /  60  60  40  30
DLN  44  62  41  63 /  30  50  30  30
HVR  42  70  41  71 /  20  20  10  20
LWT  45  61  42  61 /  50  50  20  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 230140
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
740 PM MDT FRI MAY 22 2015

.UPDATE...
HAVE MADE SOME ADJUSTMENTS TO POPS TONIGHT BASED ON LATEST TRENDS
IN SATELLITE AND RADAR DATA. SCATTERED SHORT-LIVED SHOWERS AND
ISOLATED THUNDERSTORMS HAVE DEVELOPED OVER CASCADE...CHOUTEAU AND
SOUTHERN BLAINE COUNTIES WHERE POPS WERE INCREASED THIS EVENING AS
THIS ACTIVITY CONTINUES TO PUSH SLOWLY WESTWARD. SHOULD SEE A
GENERAL DISSIPATING TREND AFTER 04Z...BUT SOME SHOWERS COULD
LINGER THROUGH THE NIGHT ACROSS JUDITH BASIN...FERGUS AND BLAINE
COUNTIES AS A WEAK DISTURBANCE ROTATES AROUND THE BROAD UPPER LOW
CENTERED OVER THE GREAT BASIN INTO EASTERN PORTIONS OF CENTRAL MT
LATE TONIGHT. HOENISCH

&&

.AVIATION...

UPDATED 2326Z.

CENTRAL AND SOUTHWEST MONTANA WILL REMAIN UNDER THE INFLUENCE OF A
WEAK UPPER LEVEL LOW PRESSURE TROF THROUGH SATURDAY. THE AIRMASS
WILL REMAIN RATHER MOIST AT MID-LEVELS ACROSS SOUTHWEST MONTANA
TONIGHT. THIS MOISTURE WILL CREEP FARTHER NORTH SATURDAY AND PUSH
INTO THE HILINE BY AFTERNOON. ISOLATED THUNDERSTORMS WILL END THIS
EVENING BUT A CHANCE OF THUNDERSTORMS WILL DEVELOP AGAIN SATURDAY
AFTERNOON. LOCAL MVFR CIGS ARE POSSIBLE NEAR SHOWERS AND
THUNDERSTORMS BUT ELSEWHERE VFR CONDITIONS WILL PREVAIL THROUGH THE
NEXT 24 HOURS.

&&

.PREV DISCUSSION...
/ISSUED 528 PM MDT FRI MAY 22 2015/
CURRENT RADAR/SATELLITE IMAGERY SHOWING SCATTERED SHOWERS AND A FEW
SMALL THUNDERSTORMS DEVELOPING MAINLY FROM THE LITTLE BELT AND SNOWY
MTNS SOUTH TO THE MT/ID BORDER.  EXPECT PRECIPITATION COVERAGE TO
INCREASE OVER THE SOUTHWEST COUNTIES AND EXTEND INTO PARTS OF
CASCADE/CHOUTEAU/FERGUS/JUDITH BASIN COUNTIES BY LATE AFTN AS
ADDITIONAL MOISTURE ARRIVES FROM IDAHO/WYOMING.  MOISTURE PUSH IS
DRIVEN BY A SLOW-MOVING UPPER-LEVEL LOW PRESSURE AREA PRESENTLY
CENTERED AT THE CA/NV/AZ BORDER.  FORECAST MODELS REMAIN IN VERY
GOOD AGREEMENT THAT THE LOW WILL TRACK GRADUALLY TO THE NORTHEAST
THROUGH THE GREAT BASIN OVER THE WEEKEND, REACHING EASTERN WYOMING
BY MIDDAY SUNDAY.  AS IT MOVES, EAST-SOUTHEAST WINDS ON THE
FRONTSIDE OF THE LOW`S CIRCULATION WILL BRING BOTH PACIFIC AND SOME
GULF OF MEXICO MOISTURE INTO MT, PRODUCING SCATTERED SHOWERS AND
THUNDERSTORMS EACH AFTERNOON AND EVENING THROUGH SUNDAY. NO STRONG
OR SEVERE STORMS ARE EXPECTED AT THIS TIME, AS INSTABILITY AND WIND
SHEAR PARAMETERS ARE FORECAST TO BE WEAK FOR THE NEXT COUPLE DAYS.
CONVECTIVE ACTIVITY WILL DISSIPATE OVER MOST OF THE FORECAST AREA
EACH EVENING NEAR/AFTER SUNSET.

LATEST MODELS ARE ALSO INDICATING A BETTER CHANCE OF SHORT-TERM DRY
CONDITIONS ON MONDAY AS OUR REGION WILL BE BETWEEN THE EXITING
WEEKEND WEATHER SYSTEM AND THE NEXT SHORTWAVE TROF MOVING INTO THE
PACIFIC NORTHWEST. ISOLATED SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE ALONG THE ROCKY MTN FRONT AND PARTS OF SOUTHWEST MT MON
AFTN/EVE AS THE TROF TAPS INTO RESIDUAL MOISTURE OVER WESTERN MT,
WHILE LOCATIONS GENERALLY ALONG/EAST OF THE INTERSTATE 15 CORRIDOR
REMAIN PRECIP FREE.
WARANAUSKAS

MONDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT
IN A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO
MIDWEEK. THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED
MONDAY NIGHT THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH
THEIR FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER
LOW NEAR VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS
IT MOVES INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER
LOW SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON
FRIDAY. DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR
PRECIPITATION FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM
TUESDAY ON OF SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS
THE CANADIAN BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED
THUNDERSTORMS DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO
NOT ANTICIPATE ANY SEVERE STORMS AT THIS TIME.
BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  47  64  43  65 /  50  40  20  20
CTB  42  67  38  67 /  10  20  10  10
HLN  48  64  45  67 /  40  70  40  20
BZN  42  61  41  62 /  20  60  40  40
WEY  34  57  33  57 /  60  60  40  30
DLN  44  62  41  63 /  30  50  30  30
HVR  42  70  41  71 /  20  20  10  20
LWT  45  61  42  61 /  50  50  20  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS




000
FXUS65 KTFX 230140
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
740 PM MDT FRI MAY 22 2015

.UPDATE...
HAVE MADE SOME ADJUSTMENTS TO POPS TONIGHT BASED ON LATEST TRENDS
IN SATELLITE AND RADAR DATA. SCATTERED SHORT-LIVED SHOWERS AND
ISOLATED THUNDERSTORMS HAVE DEVELOPED OVER CASCADE...CHOUTEAU AND
SOUTHERN BLAINE COUNTIES WHERE POPS WERE INCREASED THIS EVENING AS
THIS ACTIVITY CONTINUES TO PUSH SLOWLY WESTWARD. SHOULD SEE A
GENERAL DISSIPATING TREND AFTER 04Z...BUT SOME SHOWERS COULD
LINGER THROUGH THE NIGHT ACROSS JUDITH BASIN...FERGUS AND BLAINE
COUNTIES AS A WEAK DISTURBANCE ROTATES AROUND THE BROAD UPPER LOW
CENTERED OVER THE GREAT BASIN INTO EASTERN PORTIONS OF CENTRAL MT
LATE TONIGHT. HOENISCH

&&

.AVIATION...

UPDATED 2326Z.

CENTRAL AND SOUTHWEST MONTANA WILL REMAIN UNDER THE INFLUENCE OF A
WEAK UPPER LEVEL LOW PRESSURE TROF THROUGH SATURDAY. THE AIRMASS
WILL REMAIN RATHER MOIST AT MID-LEVELS ACROSS SOUTHWEST MONTANA
TONIGHT. THIS MOISTURE WILL CREEP FARTHER NORTH SATURDAY AND PUSH
INTO THE HILINE BY AFTERNOON. ISOLATED THUNDERSTORMS WILL END THIS
EVENING BUT A CHANCE OF THUNDERSTORMS WILL DEVELOP AGAIN SATURDAY
AFTERNOON. LOCAL MVFR CIGS ARE POSSIBLE NEAR SHOWERS AND
THUNDERSTORMS BUT ELSEWHERE VFR CONDITIONS WILL PREVAIL THROUGH THE
NEXT 24 HOURS.

&&

.PREV DISCUSSION...
/ISSUED 528 PM MDT FRI MAY 22 2015/
CURRENT RADAR/SATELLITE IMAGERY SHOWING SCATTERED SHOWERS AND A FEW
SMALL THUNDERSTORMS DEVELOPING MAINLY FROM THE LITTLE BELT AND SNOWY
MTNS SOUTH TO THE MT/ID BORDER.  EXPECT PRECIPITATION COVERAGE TO
INCREASE OVER THE SOUTHWEST COUNTIES AND EXTEND INTO PARTS OF
CASCADE/CHOUTEAU/FERGUS/JUDITH BASIN COUNTIES BY LATE AFTN AS
ADDITIONAL MOISTURE ARRIVES FROM IDAHO/WYOMING.  MOISTURE PUSH IS
DRIVEN BY A SLOW-MOVING UPPER-LEVEL LOW PRESSURE AREA PRESENTLY
CENTERED AT THE CA/NV/AZ BORDER.  FORECAST MODELS REMAIN IN VERY
GOOD AGREEMENT THAT THE LOW WILL TRACK GRADUALLY TO THE NORTHEAST
THROUGH THE GREAT BASIN OVER THE WEEKEND, REACHING EASTERN WYOMING
BY MIDDAY SUNDAY.  AS IT MOVES, EAST-SOUTHEAST WINDS ON THE
FRONTSIDE OF THE LOW`S CIRCULATION WILL BRING BOTH PACIFIC AND SOME
GULF OF MEXICO MOISTURE INTO MT, PRODUCING SCATTERED SHOWERS AND
THUNDERSTORMS EACH AFTERNOON AND EVENING THROUGH SUNDAY. NO STRONG
OR SEVERE STORMS ARE EXPECTED AT THIS TIME, AS INSTABILITY AND WIND
SHEAR PARAMETERS ARE FORECAST TO BE WEAK FOR THE NEXT COUPLE DAYS.
CONVECTIVE ACTIVITY WILL DISSIPATE OVER MOST OF THE FORECAST AREA
EACH EVENING NEAR/AFTER SUNSET.

LATEST MODELS ARE ALSO INDICATING A BETTER CHANCE OF SHORT-TERM DRY
CONDITIONS ON MONDAY AS OUR REGION WILL BE BETWEEN THE EXITING
WEEKEND WEATHER SYSTEM AND THE NEXT SHORTWAVE TROF MOVING INTO THE
PACIFIC NORTHWEST. ISOLATED SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE ALONG THE ROCKY MTN FRONT AND PARTS OF SOUTHWEST MT MON
AFTN/EVE AS THE TROF TAPS INTO RESIDUAL MOISTURE OVER WESTERN MT,
WHILE LOCATIONS GENERALLY ALONG/EAST OF THE INTERSTATE 15 CORRIDOR
REMAIN PRECIP FREE.
WARANAUSKAS

MONDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT
IN A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO
MIDWEEK. THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED
MONDAY NIGHT THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH
THEIR FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER
LOW NEAR VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS
IT MOVES INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER
LOW SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON
FRIDAY. DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR
PRECIPITATION FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM
TUESDAY ON OF SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS
THE CANADIAN BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED
THUNDERSTORMS DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO
NOT ANTICIPATE ANY SEVERE STORMS AT THIS TIME.
BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  47  64  43  65 /  50  40  20  20
CTB  42  67  38  67 /  10  20  10  10
HLN  48  64  45  67 /  40  70  40  20
BZN  42  61  41  62 /  20  60  40  40
WEY  34  57  33  57 /  60  60  40  30
DLN  44  62  41  63 /  30  50  30  30
HVR  42  70  41  71 /  20  20  10  20
LWT  45  61  42  61 /  50  50  20  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS


  [top]

000
FXUS65 KGGW 230136
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
736 PM MDT FRI MAY 22 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SUNDAY...

UPDATE...
ISOLATED SHOWERS AND RUMBLES OF THUNDER CONTINUE TO THE SOUTH AND
WEST OF GLASGOW THIS EVENING. THE THREAT OF SHOWERS WILL CONTINUE
ALL NIGHT. THE WIND WILL CONTINUE TO DIMINISH ACROSS THE REGION
TONIGHT. THIS ALLOWED FOR THE CANCELLATION OF THE LAKE WIND
ADVISORY FOR FORT PECK LAKE. OTHERWISE THE FORECAST REMAINS ON
TRACK FOR THE REGION.      PROTON

PREVIOUS DISCUSSION...
WATER VAPOR SHOWING A DEEP UPPER TROUGH THAT HAS DUG INTO THE BAJA
OF MEXICO TODAY. MOISTURE AT ALL LEVELS HAVE INCREASED OVER MONTANA
AS A RESULT AND THIS WILL ALSO INCREASE THE CHANCE FOR SHOWERS
OVER THE WEEKEND IN SOME AREAS.

MODELS DEPICTING A COMPLEX EVOLUTION OF SHOWERS THROUGH THIS PERIOD.
FIRST BATCH LOOKS TO FORM FROM INCREASING INSTABILITY OVER THE
CENTRAL AREAS OF MONTANA. SCATTERED AND ISOLATED TSTORMS MAY SPILL
INTO THE SW ZONES THIS EVENING.

THE NEXT BATCH OF PRECIPITATION MOVES NORTH OUT OF WYOMING TOWARD
THE SE ZONES. THE GFS BRINGS UP AN ASSOCIATED LOW CUTTING IT OFF AND
ALLOWING THE PRECIPITATION TO SOAK THE SE ZONES. THE NAM AND EC KEEP
THE WAVE OPEN AND THEREFORE PUSH MUCH OF THE MOISTURE TO OUR EAST.
BEING THAT IT HAS BEEN DRIER THAN NORMAL...HAVE SIDED WITH THE DRIER
SOLUTIONS.

EVEN IF THE RAINFALL MISSES THE AREA...COOLER TEMPERATURES CAN BE
EXPECTED OVER THE SE ZONES. TEMPERATURES ARE ONLY EXPECTED TO TOP
OUT IN THE LOWER 60S AFTER HIGHS NEAR 70 TODAY.

WINDS SATURDAY WILL BE LIGHTER THAN TODAY AND LOOK TO BE LESS THAN
LAKE WIND ADVISORY CRITERIA. TFJ


.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...

AFTERNOON UPDATE...
MOST OF THE LONG TERM STANDS WITH CHANGES BEING MINOR. SPLIT FLOW
IS MAINTAINED FROM SUNDAY NIGHT TO WEDNESDAY WITH UNTIMEABLE
SHORTWAVES LEADING TO WASHED OUT POPS.

A STRONG SIGNAL IS SHOWING UP FOR A TROUGH TO DROP INTO MONTANA
THURSDAY AFTERNOON AND BRING A FAIRLY SUBSTANTIAL COLD FRONT. HAVE
BIT ON THIS SIGNAL FROM BOTH THE EC AND GFS...BUT THERE MAY STILL
BE SOME ROOM TO DROP TEMPERATURES LOWER. COLD POOL WILL PROBABLY
KICK OUT BY THE WEEKEND AND JUST BEYOND THE NORMAL FORECAST RANGE.
GAH

PREVIOUS LONG TERM DISCUSSION...
MODELS HAVE THEIR DIFFERENCES WITH THE UPPER TROUGH/LOW LIFTING
NORTH INTO MONTANA AND THE DAKOTAS SUNDAY NIGHT AND MONDAY. ECMWF
MAINTAINS AN OPEN TROUGH AND KEEPS MOST OF THE MOISTURE TO THE
EAST WHILE THE GFS HAS A CLOSED LOW AND PUSHES MOISTURE FURTHER
WEST INTO EASTERN MONTANA. WILL SPLIT THE DIFFERENCE FOR NOW AND
MAINTAIN HIGHER POPS IN THE EAST.

THE REST OF THE PERIOD...MODELS TIME SYSTEMS DIFFERENTLY BUT EACH
ONE HAS FREQUENT SHORTWAVE TROUGHS GOING THROUGH MONTANA WHICH
WOULD LEAD TO SHOWERS AND THUNDERSTORMS AT TIMES THAT WOULD BE TOO
DIFFICULT TO TIME. WILL MAINTAIN CHANCE/SLIGHT CHANCE OF SHOWERS
AND THUNDERSTORMS THROUGH THE WEEK. FORRESTER

&&

.AVIATION...
FLIGHT CATEGORY: VFR.

SYNOPSIS: BROKEN MID-LEVEL THIS EVENING. AN UPPER LEVEL DISTURBANCE
MOVES INTO THE AREA OVERNIGHT AND COULD INITIATE A FEW RAIN
SHOWERS AND ISOLATED THUNDER AT KGDV AND KSDY TERMINALS LASTING
THROUGH SUNDAY.

AREA WINDS: EAST AROUND 10 KNOTS NEAR SUNSET...INCREASING TO 10
TO 20 KTS AGAIN AFTER SUNRISE.

GAH/SCT


&&

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

&&

$$

WEATHER.GOV/GLASGOW





000
FXUS65 KGGW 230136
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
736 PM MDT FRI MAY 22 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SUNDAY...

UPDATE...
ISOLATED SHOWERS AND RUMBLES OF THUNDER CONTINUE TO THE SOUTH AND
WEST OF GLASGOW THIS EVENING. THE THREAT OF SHOWERS WILL CONTINUE
ALL NIGHT. THE WIND WILL CONTINUE TO DIMINISH ACROSS THE REGION
TONIGHT. THIS ALLOWED FOR THE CANCELLATION OF THE LAKE WIND
ADVISORY FOR FORT PECK LAKE. OTHERWISE THE FORECAST REMAINS ON
TRACK FOR THE REGION.      PROTON

PREVIOUS DISCUSSION...
WATER VAPOR SHOWING A DEEP UPPER TROUGH THAT HAS DUG INTO THE BAJA
OF MEXICO TODAY. MOISTURE AT ALL LEVELS HAVE INCREASED OVER MONTANA
AS A RESULT AND THIS WILL ALSO INCREASE THE CHANCE FOR SHOWERS
OVER THE WEEKEND IN SOME AREAS.

MODELS DEPICTING A COMPLEX EVOLUTION OF SHOWERS THROUGH THIS PERIOD.
FIRST BATCH LOOKS TO FORM FROM INCREASING INSTABILITY OVER THE
CENTRAL AREAS OF MONTANA. SCATTERED AND ISOLATED TSTORMS MAY SPILL
INTO THE SW ZONES THIS EVENING.

THE NEXT BATCH OF PRECIPITATION MOVES NORTH OUT OF WYOMING TOWARD
THE SE ZONES. THE GFS BRINGS UP AN ASSOCIATED LOW CUTTING IT OFF AND
ALLOWING THE PRECIPITATION TO SOAK THE SE ZONES. THE NAM AND EC KEEP
THE WAVE OPEN AND THEREFORE PUSH MUCH OF THE MOISTURE TO OUR EAST.
BEING THAT IT HAS BEEN DRIER THAN NORMAL...HAVE SIDED WITH THE DRIER
SOLUTIONS.

EVEN IF THE RAINFALL MISSES THE AREA...COOLER TEMPERATURES CAN BE
EXPECTED OVER THE SE ZONES. TEMPERATURES ARE ONLY EXPECTED TO TOP
OUT IN THE LOWER 60S AFTER HIGHS NEAR 70 TODAY.

WINDS SATURDAY WILL BE LIGHTER THAN TODAY AND LOOK TO BE LESS THAN
LAKE WIND ADVISORY CRITERIA. TFJ


.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...

AFTERNOON UPDATE...
MOST OF THE LONG TERM STANDS WITH CHANGES BEING MINOR. SPLIT FLOW
IS MAINTAINED FROM SUNDAY NIGHT TO WEDNESDAY WITH UNTIMEABLE
SHORTWAVES LEADING TO WASHED OUT POPS.

A STRONG SIGNAL IS SHOWING UP FOR A TROUGH TO DROP INTO MONTANA
THURSDAY AFTERNOON AND BRING A FAIRLY SUBSTANTIAL COLD FRONT. HAVE
BIT ON THIS SIGNAL FROM BOTH THE EC AND GFS...BUT THERE MAY STILL
BE SOME ROOM TO DROP TEMPERATURES LOWER. COLD POOL WILL PROBABLY
KICK OUT BY THE WEEKEND AND JUST BEYOND THE NORMAL FORECAST RANGE.
GAH

PREVIOUS LONG TERM DISCUSSION...
MODELS HAVE THEIR DIFFERENCES WITH THE UPPER TROUGH/LOW LIFTING
NORTH INTO MONTANA AND THE DAKOTAS SUNDAY NIGHT AND MONDAY. ECMWF
MAINTAINS AN OPEN TROUGH AND KEEPS MOST OF THE MOISTURE TO THE
EAST WHILE THE GFS HAS A CLOSED LOW AND PUSHES MOISTURE FURTHER
WEST INTO EASTERN MONTANA. WILL SPLIT THE DIFFERENCE FOR NOW AND
MAINTAIN HIGHER POPS IN THE EAST.

THE REST OF THE PERIOD...MODELS TIME SYSTEMS DIFFERENTLY BUT EACH
ONE HAS FREQUENT SHORTWAVE TROUGHS GOING THROUGH MONTANA WHICH
WOULD LEAD TO SHOWERS AND THUNDERSTORMS AT TIMES THAT WOULD BE TOO
DIFFICULT TO TIME. WILL MAINTAIN CHANCE/SLIGHT CHANCE OF SHOWERS
AND THUNDERSTORMS THROUGH THE WEEK. FORRESTER

&&

.AVIATION...
FLIGHT CATEGORY: VFR.

SYNOPSIS: BROKEN MID-LEVEL THIS EVENING. AN UPPER LEVEL DISTURBANCE
MOVES INTO THE AREA OVERNIGHT AND COULD INITIATE A FEW RAIN
SHOWERS AND ISOLATED THUNDER AT KGDV AND KSDY TERMINALS LASTING
THROUGH SUNDAY.

AREA WINDS: EAST AROUND 10 KNOTS NEAR SUNSET...INCREASING TO 10
TO 20 KTS AGAIN AFTER SUNRISE.

GAH/SCT


&&

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

&&

$$

WEATHER.GOV/GLASGOW





000
FXUS65 KGGW 230136
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
736 PM MDT FRI MAY 22 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SUNDAY...

UPDATE...
ISOLATED SHOWERS AND RUMBLES OF THUNDER CONTINUE TO THE SOUTH AND
WEST OF GLASGOW THIS EVENING. THE THREAT OF SHOWERS WILL CONTINUE
ALL NIGHT. THE WIND WILL CONTINUE TO DIMINISH ACROSS THE REGION
TONIGHT. THIS ALLOWED FOR THE CANCELLATION OF THE LAKE WIND
ADVISORY FOR FORT PECK LAKE. OTHERWISE THE FORECAST REMAINS ON
TRACK FOR THE REGION.      PROTON

PREVIOUS DISCUSSION...
WATER VAPOR SHOWING A DEEP UPPER TROUGH THAT HAS DUG INTO THE BAJA
OF MEXICO TODAY. MOISTURE AT ALL LEVELS HAVE INCREASED OVER MONTANA
AS A RESULT AND THIS WILL ALSO INCREASE THE CHANCE FOR SHOWERS
OVER THE WEEKEND IN SOME AREAS.

MODELS DEPICTING A COMPLEX EVOLUTION OF SHOWERS THROUGH THIS PERIOD.
FIRST BATCH LOOKS TO FORM FROM INCREASING INSTABILITY OVER THE
CENTRAL AREAS OF MONTANA. SCATTERED AND ISOLATED TSTORMS MAY SPILL
INTO THE SW ZONES THIS EVENING.

THE NEXT BATCH OF PRECIPITATION MOVES NORTH OUT OF WYOMING TOWARD
THE SE ZONES. THE GFS BRINGS UP AN ASSOCIATED LOW CUTTING IT OFF AND
ALLOWING THE PRECIPITATION TO SOAK THE SE ZONES. THE NAM AND EC KEEP
THE WAVE OPEN AND THEREFORE PUSH MUCH OF THE MOISTURE TO OUR EAST.
BEING THAT IT HAS BEEN DRIER THAN NORMAL...HAVE SIDED WITH THE DRIER
SOLUTIONS.

EVEN IF THE RAINFALL MISSES THE AREA...COOLER TEMPERATURES CAN BE
EXPECTED OVER THE SE ZONES. TEMPERATURES ARE ONLY EXPECTED TO TOP
OUT IN THE LOWER 60S AFTER HIGHS NEAR 70 TODAY.

WINDS SATURDAY WILL BE LIGHTER THAN TODAY AND LOOK TO BE LESS THAN
LAKE WIND ADVISORY CRITERIA. TFJ


.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...

AFTERNOON UPDATE...
MOST OF THE LONG TERM STANDS WITH CHANGES BEING MINOR. SPLIT FLOW
IS MAINTAINED FROM SUNDAY NIGHT TO WEDNESDAY WITH UNTIMEABLE
SHORTWAVES LEADING TO WASHED OUT POPS.

A STRONG SIGNAL IS SHOWING UP FOR A TROUGH TO DROP INTO MONTANA
THURSDAY AFTERNOON AND BRING A FAIRLY SUBSTANTIAL COLD FRONT. HAVE
BIT ON THIS SIGNAL FROM BOTH THE EC AND GFS...BUT THERE MAY STILL
BE SOME ROOM TO DROP TEMPERATURES LOWER. COLD POOL WILL PROBABLY
KICK OUT BY THE WEEKEND AND JUST BEYOND THE NORMAL FORECAST RANGE.
GAH

PREVIOUS LONG TERM DISCUSSION...
MODELS HAVE THEIR DIFFERENCES WITH THE UPPER TROUGH/LOW LIFTING
NORTH INTO MONTANA AND THE DAKOTAS SUNDAY NIGHT AND MONDAY. ECMWF
MAINTAINS AN OPEN TROUGH AND KEEPS MOST OF THE MOISTURE TO THE
EAST WHILE THE GFS HAS A CLOSED LOW AND PUSHES MOISTURE FURTHER
WEST INTO EASTERN MONTANA. WILL SPLIT THE DIFFERENCE FOR NOW AND
MAINTAIN HIGHER POPS IN THE EAST.

THE REST OF THE PERIOD...MODELS TIME SYSTEMS DIFFERENTLY BUT EACH
ONE HAS FREQUENT SHORTWAVE TROUGHS GOING THROUGH MONTANA WHICH
WOULD LEAD TO SHOWERS AND THUNDERSTORMS AT TIMES THAT WOULD BE TOO
DIFFICULT TO TIME. WILL MAINTAIN CHANCE/SLIGHT CHANCE OF SHOWERS
AND THUNDERSTORMS THROUGH THE WEEK. FORRESTER

&&

.AVIATION...
FLIGHT CATEGORY: VFR.

SYNOPSIS: BROKEN MID-LEVEL THIS EVENING. AN UPPER LEVEL DISTURBANCE
MOVES INTO THE AREA OVERNIGHT AND COULD INITIATE A FEW RAIN
SHOWERS AND ISOLATED THUNDER AT KGDV AND KSDY TERMINALS LASTING
THROUGH SUNDAY.

AREA WINDS: EAST AROUND 10 KNOTS NEAR SUNSET...INCREASING TO 10
TO 20 KTS AGAIN AFTER SUNRISE.

GAH/SCT


&&

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

&&

$$

WEATHER.GOV/GLASGOW





000
FXUS65 KGGW 230136
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
736 PM MDT FRI MAY 22 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SUNDAY...

UPDATE...
ISOLATED SHOWERS AND RUMBLES OF THUNDER CONTINUE TO THE SOUTH AND
WEST OF GLASGOW THIS EVENING. THE THREAT OF SHOWERS WILL CONTINUE
ALL NIGHT. THE WIND WILL CONTINUE TO DIMINISH ACROSS THE REGION
TONIGHT. THIS ALLOWED FOR THE CANCELLATION OF THE LAKE WIND
ADVISORY FOR FORT PECK LAKE. OTHERWISE THE FORECAST REMAINS ON
TRACK FOR THE REGION.      PROTON

PREVIOUS DISCUSSION...
WATER VAPOR SHOWING A DEEP UPPER TROUGH THAT HAS DUG INTO THE BAJA
OF MEXICO TODAY. MOISTURE AT ALL LEVELS HAVE INCREASED OVER MONTANA
AS A RESULT AND THIS WILL ALSO INCREASE THE CHANCE FOR SHOWERS
OVER THE WEEKEND IN SOME AREAS.

MODELS DEPICTING A COMPLEX EVOLUTION OF SHOWERS THROUGH THIS PERIOD.
FIRST BATCH LOOKS TO FORM FROM INCREASING INSTABILITY OVER THE
CENTRAL AREAS OF MONTANA. SCATTERED AND ISOLATED TSTORMS MAY SPILL
INTO THE SW ZONES THIS EVENING.

THE NEXT BATCH OF PRECIPITATION MOVES NORTH OUT OF WYOMING TOWARD
THE SE ZONES. THE GFS BRINGS UP AN ASSOCIATED LOW CUTTING IT OFF AND
ALLOWING THE PRECIPITATION TO SOAK THE SE ZONES. THE NAM AND EC KEEP
THE WAVE OPEN AND THEREFORE PUSH MUCH OF THE MOISTURE TO OUR EAST.
BEING THAT IT HAS BEEN DRIER THAN NORMAL...HAVE SIDED WITH THE DRIER
SOLUTIONS.

EVEN IF THE RAINFALL MISSES THE AREA...COOLER TEMPERATURES CAN BE
EXPECTED OVER THE SE ZONES. TEMPERATURES ARE ONLY EXPECTED TO TOP
OUT IN THE LOWER 60S AFTER HIGHS NEAR 70 TODAY.

WINDS SATURDAY WILL BE LIGHTER THAN TODAY AND LOOK TO BE LESS THAN
LAKE WIND ADVISORY CRITERIA. TFJ


.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...

AFTERNOON UPDATE...
MOST OF THE LONG TERM STANDS WITH CHANGES BEING MINOR. SPLIT FLOW
IS MAINTAINED FROM SUNDAY NIGHT TO WEDNESDAY WITH UNTIMEABLE
SHORTWAVES LEADING TO WASHED OUT POPS.

A STRONG SIGNAL IS SHOWING UP FOR A TROUGH TO DROP INTO MONTANA
THURSDAY AFTERNOON AND BRING A FAIRLY SUBSTANTIAL COLD FRONT. HAVE
BIT ON THIS SIGNAL FROM BOTH THE EC AND GFS...BUT THERE MAY STILL
BE SOME ROOM TO DROP TEMPERATURES LOWER. COLD POOL WILL PROBABLY
KICK OUT BY THE WEEKEND AND JUST BEYOND THE NORMAL FORECAST RANGE.
GAH

PREVIOUS LONG TERM DISCUSSION...
MODELS HAVE THEIR DIFFERENCES WITH THE UPPER TROUGH/LOW LIFTING
NORTH INTO MONTANA AND THE DAKOTAS SUNDAY NIGHT AND MONDAY. ECMWF
MAINTAINS AN OPEN TROUGH AND KEEPS MOST OF THE MOISTURE TO THE
EAST WHILE THE GFS HAS A CLOSED LOW AND PUSHES MOISTURE FURTHER
WEST INTO EASTERN MONTANA. WILL SPLIT THE DIFFERENCE FOR NOW AND
MAINTAIN HIGHER POPS IN THE EAST.

THE REST OF THE PERIOD...MODELS TIME SYSTEMS DIFFERENTLY BUT EACH
ONE HAS FREQUENT SHORTWAVE TROUGHS GOING THROUGH MONTANA WHICH
WOULD LEAD TO SHOWERS AND THUNDERSTORMS AT TIMES THAT WOULD BE TOO
DIFFICULT TO TIME. WILL MAINTAIN CHANCE/SLIGHT CHANCE OF SHOWERS
AND THUNDERSTORMS THROUGH THE WEEK. FORRESTER

&&

.AVIATION...
FLIGHT CATEGORY: VFR.

SYNOPSIS: BROKEN MID-LEVEL THIS EVENING. AN UPPER LEVEL DISTURBANCE
MOVES INTO THE AREA OVERNIGHT AND COULD INITIATE A FEW RAIN
SHOWERS AND ISOLATED THUNDER AT KGDV AND KSDY TERMINALS LASTING
THROUGH SUNDAY.

AREA WINDS: EAST AROUND 10 KNOTS NEAR SUNSET...INCREASING TO 10
TO 20 KTS AGAIN AFTER SUNRISE.

GAH/SCT


&&

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

&&

$$

WEATHER.GOV/GLASGOW





000
FXUS65 KTFX 222329
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
528 PM MDT FRI MAY 22 2015

.DISCUSSION...THIS AFTERNOON THROUGH MEMORIAL DAY AFTERNOON.
CURRENT RADAR/SATELLITE IMAGERY SHOWING SCATTERED SHOWERS AND A FEW
SMALL THUNDERSTORMS DEVELOPING MAINLY FROM THE LITTLE BELT AND SNOWY
MTNS SOUTH TO THE MT/ID BORDER.  EXPECT PRECIPITATION COVERAGE TO
INCREASE OVER THE SOUTHWEST COUNTIES AND EXTEND INTO PARTS OF
CASCADE/CHOUTEAU/FERGUS/JUDITH BASIN COUNTIES BY LATE AFTN AS
ADDITIONAL MOISTURE ARRIVES FROM IDAHO/WYOMING.  MOISTURE PUSH IS
DRIVEN BY A SLOW-MOVING UPPER-LEVEL LOW PRESSURE AREA PRESENTLY
CENTERED AT THE CA/NV/AZ BORDER.  FORECAST MODELS REMAIN IN VERY
GOOD AGREEMENT THAT THE LOW WILL TRACK GRADUALLY TO THE NORTHEAST
THROUGH THE GREAT BASIN OVER THE WEEKEND, REACHING EASTERN WYOMING
BY MIDDAY SUNDAY.  AS IT MOVES, EAST-SOUTHEAST WINDS ON THE
FRONTSIDE OF THE LOW`S CIRCULATION WILL BRING BOTH PACIFIC AND SOME
GULF OF MEXICO MOISTURE INTO MT, PRODUCING SCATTERED SHOWERS AND
THUNDERSTORMS EACH AFTERNOON AND EVENING THROUGH SUNDAY. NO STRONG
OR SEVERE STORMS ARE EXPECTED AT THIS TIME, AS INSTABILITY AND WIND
SHEAR PARAMETERS ARE FORECAST TO BE WEAK FOR THE NEXT COUPLE DAYS.
CONVECTIVE ACTIVITY WILL DISSIPATE OVER MOST OF THE FORECAST AREA
EACH EVENING NEAR/AFTER SUNSET.

LATEST MODELS ARE ALSO INDICATING A BETTER CHANCE OF SHORT-TERM DRY
CONDITIONS ON MONDAY AS OUR REGION WILL BE BETWEEN THE EXITING
WEEKEND WEATHER SYSTEM AND THE NEXT SHORTWAVE TROF MOVING INTO THE
PACIFIC NORTHWEST. ISOLATED SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE ALONG THE ROCKY MTN FRONT AND PARTS OF SOUTHWEST MT MON
AFTN/EVE AS THE TROF TAPS INTO RESIDUAL MOISTURE OVER WESTERN MT,
WHILE LOCATIONS GENERALLY ALONG/EAST OF THE INTERSTATE 15 CORRIDOR
REMAIN PRECIP FREE.
WARANAUSKAS


MONDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT
IN A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO
MIDWEEK. THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED
MONDAY NIGHT THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH
THEIR FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER
LOW NEAR VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS
IT MOVES INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER
LOW SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON
FRIDAY. DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR
PRECIPITATION FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM
TUESDAY ON OF SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS
THE CANADIAN BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED
THUNDERSTORMS DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO
NOT ANTICIPATE ANY SEVERE STORMS AT THIS TIME.
BLANK


&&

.AVIATION...

UPDATED 2326Z.

CENTRAL AND SOUTHWEST MONTANA WILL REMAIN UNDER THE INFLUENCE OF A
WEAK UPPER LEVEL LOW PRESSURE TROF THROUGH SATURDAY. THE AIRMASS
WILL REMAIN RATHER MOIST AT MID-LEVELS ACROSS SOUTHWEST MONTANA
TONIGHT. THIS MOISTURE WILL CREEP FARTHER NORTH SATURDAY AND PUSH
INTO THE HILINE BY AFTERNOON. ISOLATED THUNDERSTORMS WILL END THIS
EVENING BUT A CHANCE OF THUNDERSTORMS WILL DEVELOP AGAIN SATURDAY
AFTERNOON. LOCAL MVFR CIGS ARE POSSIBLE NEAR SHOWERS AND
THUNDERSTORMS BUT ELSEWHERE VFR CONDITIONS WILL PREVAIL THROUGH THE
NEXT 24 HOURS.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  47  64  43  65 /  20  40  20  20
CTB  42  67  38  67 /  10  20  10  10
HLN  48  64  45  67 /  40  70  40  20
BZN  42  61  41  62 /  30  60  40  40
WEY  34  57  33  57 /  60  60  40  30
DLN  44  62  41  63 /  30  50  30  30
HVR  42  70  41  71 /  20  20  10  20
LWT  45  61  42  61 /  40  50  20  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 222329
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
528 PM MDT FRI MAY 22 2015

.DISCUSSION...THIS AFTERNOON THROUGH MEMORIAL DAY AFTERNOON.
CURRENT RADAR/SATELLITE IMAGERY SHOWING SCATTERED SHOWERS AND A FEW
SMALL THUNDERSTORMS DEVELOPING MAINLY FROM THE LITTLE BELT AND SNOWY
MTNS SOUTH TO THE MT/ID BORDER.  EXPECT PRECIPITATION COVERAGE TO
INCREASE OVER THE SOUTHWEST COUNTIES AND EXTEND INTO PARTS OF
CASCADE/CHOUTEAU/FERGUS/JUDITH BASIN COUNTIES BY LATE AFTN AS
ADDITIONAL MOISTURE ARRIVES FROM IDAHO/WYOMING.  MOISTURE PUSH IS
DRIVEN BY A SLOW-MOVING UPPER-LEVEL LOW PRESSURE AREA PRESENTLY
CENTERED AT THE CA/NV/AZ BORDER.  FORECAST MODELS REMAIN IN VERY
GOOD AGREEMENT THAT THE LOW WILL TRACK GRADUALLY TO THE NORTHEAST
THROUGH THE GREAT BASIN OVER THE WEEKEND, REACHING EASTERN WYOMING
BY MIDDAY SUNDAY.  AS IT MOVES, EAST-SOUTHEAST WINDS ON THE
FRONTSIDE OF THE LOW`S CIRCULATION WILL BRING BOTH PACIFIC AND SOME
GULF OF MEXICO MOISTURE INTO MT, PRODUCING SCATTERED SHOWERS AND
THUNDERSTORMS EACH AFTERNOON AND EVENING THROUGH SUNDAY. NO STRONG
OR SEVERE STORMS ARE EXPECTED AT THIS TIME, AS INSTABILITY AND WIND
SHEAR PARAMETERS ARE FORECAST TO BE WEAK FOR THE NEXT COUPLE DAYS.
CONVECTIVE ACTIVITY WILL DISSIPATE OVER MOST OF THE FORECAST AREA
EACH EVENING NEAR/AFTER SUNSET.

LATEST MODELS ARE ALSO INDICATING A BETTER CHANCE OF SHORT-TERM DRY
CONDITIONS ON MONDAY AS OUR REGION WILL BE BETWEEN THE EXITING
WEEKEND WEATHER SYSTEM AND THE NEXT SHORTWAVE TROF MOVING INTO THE
PACIFIC NORTHWEST. ISOLATED SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE ALONG THE ROCKY MTN FRONT AND PARTS OF SOUTHWEST MT MON
AFTN/EVE AS THE TROF TAPS INTO RESIDUAL MOISTURE OVER WESTERN MT,
WHILE LOCATIONS GENERALLY ALONG/EAST OF THE INTERSTATE 15 CORRIDOR
REMAIN PRECIP FREE.
WARANAUSKAS


MONDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT
IN A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO
MIDWEEK. THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED
MONDAY NIGHT THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH
THEIR FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER
LOW NEAR VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS
IT MOVES INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER
LOW SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON
FRIDAY. DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR
PRECIPITATION FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM
TUESDAY ON OF SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS
THE CANADIAN BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED
THUNDERSTORMS DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO
NOT ANTICIPATE ANY SEVERE STORMS AT THIS TIME.
BLANK


&&

.AVIATION...

UPDATED 2326Z.

CENTRAL AND SOUTHWEST MONTANA WILL REMAIN UNDER THE INFLUENCE OF A
WEAK UPPER LEVEL LOW PRESSURE TROF THROUGH SATURDAY. THE AIRMASS
WILL REMAIN RATHER MOIST AT MID-LEVELS ACROSS SOUTHWEST MONTANA
TONIGHT. THIS MOISTURE WILL CREEP FARTHER NORTH SATURDAY AND PUSH
INTO THE HILINE BY AFTERNOON. ISOLATED THUNDERSTORMS WILL END THIS
EVENING BUT A CHANCE OF THUNDERSTORMS WILL DEVELOP AGAIN SATURDAY
AFTERNOON. LOCAL MVFR CIGS ARE POSSIBLE NEAR SHOWERS AND
THUNDERSTORMS BUT ELSEWHERE VFR CONDITIONS WILL PREVAIL THROUGH THE
NEXT 24 HOURS.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  47  64  43  65 /  20  40  20  20
CTB  42  67  38  67 /  10  20  10  10
HLN  48  64  45  67 /  40  70  40  20
BZN  42  61  41  62 /  30  60  40  40
WEY  34  57  33  57 /  60  60  40  30
DLN  44  62  41  63 /  30  50  30  30
HVR  42  70  41  71 /  20  20  10  20
LWT  45  61  42  61 /  40  50  20  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 222329
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
528 PM MDT FRI MAY 22 2015

.DISCUSSION...THIS AFTERNOON THROUGH MEMORIAL DAY AFTERNOON.
CURRENT RADAR/SATELLITE IMAGERY SHOWING SCATTERED SHOWERS AND A FEW
SMALL THUNDERSTORMS DEVELOPING MAINLY FROM THE LITTLE BELT AND SNOWY
MTNS SOUTH TO THE MT/ID BORDER.  EXPECT PRECIPITATION COVERAGE TO
INCREASE OVER THE SOUTHWEST COUNTIES AND EXTEND INTO PARTS OF
CASCADE/CHOUTEAU/FERGUS/JUDITH BASIN COUNTIES BY LATE AFTN AS
ADDITIONAL MOISTURE ARRIVES FROM IDAHO/WYOMING.  MOISTURE PUSH IS
DRIVEN BY A SLOW-MOVING UPPER-LEVEL LOW PRESSURE AREA PRESENTLY
CENTERED AT THE CA/NV/AZ BORDER.  FORECAST MODELS REMAIN IN VERY
GOOD AGREEMENT THAT THE LOW WILL TRACK GRADUALLY TO THE NORTHEAST
THROUGH THE GREAT BASIN OVER THE WEEKEND, REACHING EASTERN WYOMING
BY MIDDAY SUNDAY.  AS IT MOVES, EAST-SOUTHEAST WINDS ON THE
FRONTSIDE OF THE LOW`S CIRCULATION WILL BRING BOTH PACIFIC AND SOME
GULF OF MEXICO MOISTURE INTO MT, PRODUCING SCATTERED SHOWERS AND
THUNDERSTORMS EACH AFTERNOON AND EVENING THROUGH SUNDAY. NO STRONG
OR SEVERE STORMS ARE EXPECTED AT THIS TIME, AS INSTABILITY AND WIND
SHEAR PARAMETERS ARE FORECAST TO BE WEAK FOR THE NEXT COUPLE DAYS.
CONVECTIVE ACTIVITY WILL DISSIPATE OVER MOST OF THE FORECAST AREA
EACH EVENING NEAR/AFTER SUNSET.

LATEST MODELS ARE ALSO INDICATING A BETTER CHANCE OF SHORT-TERM DRY
CONDITIONS ON MONDAY AS OUR REGION WILL BE BETWEEN THE EXITING
WEEKEND WEATHER SYSTEM AND THE NEXT SHORTWAVE TROF MOVING INTO THE
PACIFIC NORTHWEST. ISOLATED SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE ALONG THE ROCKY MTN FRONT AND PARTS OF SOUTHWEST MT MON
AFTN/EVE AS THE TROF TAPS INTO RESIDUAL MOISTURE OVER WESTERN MT,
WHILE LOCATIONS GENERALLY ALONG/EAST OF THE INTERSTATE 15 CORRIDOR
REMAIN PRECIP FREE.
WARANAUSKAS


MONDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT
IN A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO
MIDWEEK. THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED
MONDAY NIGHT THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH
THEIR FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER
LOW NEAR VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS
IT MOVES INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER
LOW SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON
FRIDAY. DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR
PRECIPITATION FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM
TUESDAY ON OF SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS
THE CANADIAN BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED
THUNDERSTORMS DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO
NOT ANTICIPATE ANY SEVERE STORMS AT THIS TIME.
BLANK


&&

.AVIATION...

UPDATED 2326Z.

CENTRAL AND SOUTHWEST MONTANA WILL REMAIN UNDER THE INFLUENCE OF A
WEAK UPPER LEVEL LOW PRESSURE TROF THROUGH SATURDAY. THE AIRMASS
WILL REMAIN RATHER MOIST AT MID-LEVELS ACROSS SOUTHWEST MONTANA
TONIGHT. THIS MOISTURE WILL CREEP FARTHER NORTH SATURDAY AND PUSH
INTO THE HILINE BY AFTERNOON. ISOLATED THUNDERSTORMS WILL END THIS
EVENING BUT A CHANCE OF THUNDERSTORMS WILL DEVELOP AGAIN SATURDAY
AFTERNOON. LOCAL MVFR CIGS ARE POSSIBLE NEAR SHOWERS AND
THUNDERSTORMS BUT ELSEWHERE VFR CONDITIONS WILL PREVAIL THROUGH THE
NEXT 24 HOURS.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  47  64  43  65 /  20  40  20  20
CTB  42  67  38  67 /  10  20  10  10
HLN  48  64  45  67 /  40  70  40  20
BZN  42  61  41  62 /  30  60  40  40
WEY  34  57  33  57 /  60  60  40  30
DLN  44  62  41  63 /  30  50  30  30
HVR  42  70  41  71 /  20  20  10  20
LWT  45  61  42  61 /  40  50  20  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 222329
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
528 PM MDT FRI MAY 22 2015

.DISCUSSION...THIS AFTERNOON THROUGH MEMORIAL DAY AFTERNOON.
CURRENT RADAR/SATELLITE IMAGERY SHOWING SCATTERED SHOWERS AND A FEW
SMALL THUNDERSTORMS DEVELOPING MAINLY FROM THE LITTLE BELT AND SNOWY
MTNS SOUTH TO THE MT/ID BORDER.  EXPECT PRECIPITATION COVERAGE TO
INCREASE OVER THE SOUTHWEST COUNTIES AND EXTEND INTO PARTS OF
CASCADE/CHOUTEAU/FERGUS/JUDITH BASIN COUNTIES BY LATE AFTN AS
ADDITIONAL MOISTURE ARRIVES FROM IDAHO/WYOMING.  MOISTURE PUSH IS
DRIVEN BY A SLOW-MOVING UPPER-LEVEL LOW PRESSURE AREA PRESENTLY
CENTERED AT THE CA/NV/AZ BORDER.  FORECAST MODELS REMAIN IN VERY
GOOD AGREEMENT THAT THE LOW WILL TRACK GRADUALLY TO THE NORTHEAST
THROUGH THE GREAT BASIN OVER THE WEEKEND, REACHING EASTERN WYOMING
BY MIDDAY SUNDAY.  AS IT MOVES, EAST-SOUTHEAST WINDS ON THE
FRONTSIDE OF THE LOW`S CIRCULATION WILL BRING BOTH PACIFIC AND SOME
GULF OF MEXICO MOISTURE INTO MT, PRODUCING SCATTERED SHOWERS AND
THUNDERSTORMS EACH AFTERNOON AND EVENING THROUGH SUNDAY. NO STRONG
OR SEVERE STORMS ARE EXPECTED AT THIS TIME, AS INSTABILITY AND WIND
SHEAR PARAMETERS ARE FORECAST TO BE WEAK FOR THE NEXT COUPLE DAYS.
CONVECTIVE ACTIVITY WILL DISSIPATE OVER MOST OF THE FORECAST AREA
EACH EVENING NEAR/AFTER SUNSET.

LATEST MODELS ARE ALSO INDICATING A BETTER CHANCE OF SHORT-TERM DRY
CONDITIONS ON MONDAY AS OUR REGION WILL BE BETWEEN THE EXITING
WEEKEND WEATHER SYSTEM AND THE NEXT SHORTWAVE TROF MOVING INTO THE
PACIFIC NORTHWEST. ISOLATED SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE ALONG THE ROCKY MTN FRONT AND PARTS OF SOUTHWEST MT MON
AFTN/EVE AS THE TROF TAPS INTO RESIDUAL MOISTURE OVER WESTERN MT,
WHILE LOCATIONS GENERALLY ALONG/EAST OF THE INTERSTATE 15 CORRIDOR
REMAIN PRECIP FREE.
WARANAUSKAS


MONDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT
IN A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO
MIDWEEK. THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED
MONDAY NIGHT THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH
THEIR FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER
LOW NEAR VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS
IT MOVES INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER
LOW SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON
FRIDAY. DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR
PRECIPITATION FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM
TUESDAY ON OF SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS
THE CANADIAN BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED
THUNDERSTORMS DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO
NOT ANTICIPATE ANY SEVERE STORMS AT THIS TIME.
BLANK


&&

.AVIATION...

UPDATED 2326Z.

CENTRAL AND SOUTHWEST MONTANA WILL REMAIN UNDER THE INFLUENCE OF A
WEAK UPPER LEVEL LOW PRESSURE TROF THROUGH SATURDAY. THE AIRMASS
WILL REMAIN RATHER MOIST AT MID-LEVELS ACROSS SOUTHWEST MONTANA
TONIGHT. THIS MOISTURE WILL CREEP FARTHER NORTH SATURDAY AND PUSH
INTO THE HILINE BY AFTERNOON. ISOLATED THUNDERSTORMS WILL END THIS
EVENING BUT A CHANCE OF THUNDERSTORMS WILL DEVELOP AGAIN SATURDAY
AFTERNOON. LOCAL MVFR CIGS ARE POSSIBLE NEAR SHOWERS AND
THUNDERSTORMS BUT ELSEWHERE VFR CONDITIONS WILL PREVAIL THROUGH THE
NEXT 24 HOURS.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  47  64  43  65 /  20  40  20  20
CTB  42  67  38  67 /  10  20  10  10
HLN  48  64  45  67 /  40  70  40  20
BZN  42  61  41  62 /  30  60  40  40
WEY  34  57  33  57 /  60  60  40  30
DLN  44  62  41  63 /  30  50  30  30
HVR  42  70  41  71 /  20  20  10  20
LWT  45  61  42  61 /  40  50  20  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 222329
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
528 PM MDT FRI MAY 22 2015

.DISCUSSION...THIS AFTERNOON THROUGH MEMORIAL DAY AFTERNOON.
CURRENT RADAR/SATELLITE IMAGERY SHOWING SCATTERED SHOWERS AND A FEW
SMALL THUNDERSTORMS DEVELOPING MAINLY FROM THE LITTLE BELT AND SNOWY
MTNS SOUTH TO THE MT/ID BORDER.  EXPECT PRECIPITATION COVERAGE TO
INCREASE OVER THE SOUTHWEST COUNTIES AND EXTEND INTO PARTS OF
CASCADE/CHOUTEAU/FERGUS/JUDITH BASIN COUNTIES BY LATE AFTN AS
ADDITIONAL MOISTURE ARRIVES FROM IDAHO/WYOMING.  MOISTURE PUSH IS
DRIVEN BY A SLOW-MOVING UPPER-LEVEL LOW PRESSURE AREA PRESENTLY
CENTERED AT THE CA/NV/AZ BORDER.  FORECAST MODELS REMAIN IN VERY
GOOD AGREEMENT THAT THE LOW WILL TRACK GRADUALLY TO THE NORTHEAST
THROUGH THE GREAT BASIN OVER THE WEEKEND, REACHING EASTERN WYOMING
BY MIDDAY SUNDAY.  AS IT MOVES, EAST-SOUTHEAST WINDS ON THE
FRONTSIDE OF THE LOW`S CIRCULATION WILL BRING BOTH PACIFIC AND SOME
GULF OF MEXICO MOISTURE INTO MT, PRODUCING SCATTERED SHOWERS AND
THUNDERSTORMS EACH AFTERNOON AND EVENING THROUGH SUNDAY. NO STRONG
OR SEVERE STORMS ARE EXPECTED AT THIS TIME, AS INSTABILITY AND WIND
SHEAR PARAMETERS ARE FORECAST TO BE WEAK FOR THE NEXT COUPLE DAYS.
CONVECTIVE ACTIVITY WILL DISSIPATE OVER MOST OF THE FORECAST AREA
EACH EVENING NEAR/AFTER SUNSET.

LATEST MODELS ARE ALSO INDICATING A BETTER CHANCE OF SHORT-TERM DRY
CONDITIONS ON MONDAY AS OUR REGION WILL BE BETWEEN THE EXITING
WEEKEND WEATHER SYSTEM AND THE NEXT SHORTWAVE TROF MOVING INTO THE
PACIFIC NORTHWEST. ISOLATED SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE ALONG THE ROCKY MTN FRONT AND PARTS OF SOUTHWEST MT MON
AFTN/EVE AS THE TROF TAPS INTO RESIDUAL MOISTURE OVER WESTERN MT,
WHILE LOCATIONS GENERALLY ALONG/EAST OF THE INTERSTATE 15 CORRIDOR
REMAIN PRECIP FREE.
WARANAUSKAS


MONDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT
IN A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO
MIDWEEK. THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED
MONDAY NIGHT THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH
THEIR FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER
LOW NEAR VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS
IT MOVES INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER
LOW SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON
FRIDAY. DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR
PRECIPITATION FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM
TUESDAY ON OF SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS
THE CANADIAN BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED
THUNDERSTORMS DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO
NOT ANTICIPATE ANY SEVERE STORMS AT THIS TIME.
BLANK


&&

.AVIATION...

UPDATED 2326Z.

CENTRAL AND SOUTHWEST MONTANA WILL REMAIN UNDER THE INFLUENCE OF A
WEAK UPPER LEVEL LOW PRESSURE TROF THROUGH SATURDAY. THE AIRMASS
WILL REMAIN RATHER MOIST AT MID-LEVELS ACROSS SOUTHWEST MONTANA
TONIGHT. THIS MOISTURE WILL CREEP FARTHER NORTH SATURDAY AND PUSH
INTO THE HILINE BY AFTERNOON. ISOLATED THUNDERSTORMS WILL END THIS
EVENING BUT A CHANCE OF THUNDERSTORMS WILL DEVELOP AGAIN SATURDAY
AFTERNOON. LOCAL MVFR CIGS ARE POSSIBLE NEAR SHOWERS AND
THUNDERSTORMS BUT ELSEWHERE VFR CONDITIONS WILL PREVAIL THROUGH THE
NEXT 24 HOURS.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  47  64  43  65 /  20  40  20  20
CTB  42  67  38  67 /  10  20  10  10
HLN  48  64  45  67 /  40  70  40  20
BZN  42  61  41  62 /  30  60  40  40
WEY  34  57  33  57 /  60  60  40  30
DLN  44  62  41  63 /  30  50  30  30
HVR  42  70  41  71 /  20  20  10  20
LWT  45  61  42  61 /  40  50  20  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 222329
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
528 PM MDT FRI MAY 22 2015

.DISCUSSION...THIS AFTERNOON THROUGH MEMORIAL DAY AFTERNOON.
CURRENT RADAR/SATELLITE IMAGERY SHOWING SCATTERED SHOWERS AND A FEW
SMALL THUNDERSTORMS DEVELOPING MAINLY FROM THE LITTLE BELT AND SNOWY
MTNS SOUTH TO THE MT/ID BORDER.  EXPECT PRECIPITATION COVERAGE TO
INCREASE OVER THE SOUTHWEST COUNTIES AND EXTEND INTO PARTS OF
CASCADE/CHOUTEAU/FERGUS/JUDITH BASIN COUNTIES BY LATE AFTN AS
ADDITIONAL MOISTURE ARRIVES FROM IDAHO/WYOMING.  MOISTURE PUSH IS
DRIVEN BY A SLOW-MOVING UPPER-LEVEL LOW PRESSURE AREA PRESENTLY
CENTERED AT THE CA/NV/AZ BORDER.  FORECAST MODELS REMAIN IN VERY
GOOD AGREEMENT THAT THE LOW WILL TRACK GRADUALLY TO THE NORTHEAST
THROUGH THE GREAT BASIN OVER THE WEEKEND, REACHING EASTERN WYOMING
BY MIDDAY SUNDAY.  AS IT MOVES, EAST-SOUTHEAST WINDS ON THE
FRONTSIDE OF THE LOW`S CIRCULATION WILL BRING BOTH PACIFIC AND SOME
GULF OF MEXICO MOISTURE INTO MT, PRODUCING SCATTERED SHOWERS AND
THUNDERSTORMS EACH AFTERNOON AND EVENING THROUGH SUNDAY. NO STRONG
OR SEVERE STORMS ARE EXPECTED AT THIS TIME, AS INSTABILITY AND WIND
SHEAR PARAMETERS ARE FORECAST TO BE WEAK FOR THE NEXT COUPLE DAYS.
CONVECTIVE ACTIVITY WILL DISSIPATE OVER MOST OF THE FORECAST AREA
EACH EVENING NEAR/AFTER SUNSET.

LATEST MODELS ARE ALSO INDICATING A BETTER CHANCE OF SHORT-TERM DRY
CONDITIONS ON MONDAY AS OUR REGION WILL BE BETWEEN THE EXITING
WEEKEND WEATHER SYSTEM AND THE NEXT SHORTWAVE TROF MOVING INTO THE
PACIFIC NORTHWEST. ISOLATED SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE ALONG THE ROCKY MTN FRONT AND PARTS OF SOUTHWEST MT MON
AFTN/EVE AS THE TROF TAPS INTO RESIDUAL MOISTURE OVER WESTERN MT,
WHILE LOCATIONS GENERALLY ALONG/EAST OF THE INTERSTATE 15 CORRIDOR
REMAIN PRECIP FREE.
WARANAUSKAS


MONDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT
IN A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO
MIDWEEK. THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED
MONDAY NIGHT THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH
THEIR FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER
LOW NEAR VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS
IT MOVES INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER
LOW SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON
FRIDAY. DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR
PRECIPITATION FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM
TUESDAY ON OF SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS
THE CANADIAN BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED
THUNDERSTORMS DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO
NOT ANTICIPATE ANY SEVERE STORMS AT THIS TIME.
BLANK


&&

.AVIATION...

UPDATED 2326Z.

CENTRAL AND SOUTHWEST MONTANA WILL REMAIN UNDER THE INFLUENCE OF A
WEAK UPPER LEVEL LOW PRESSURE TROF THROUGH SATURDAY. THE AIRMASS
WILL REMAIN RATHER MOIST AT MID-LEVELS ACROSS SOUTHWEST MONTANA
TONIGHT. THIS MOISTURE WILL CREEP FARTHER NORTH SATURDAY AND PUSH
INTO THE HILINE BY AFTERNOON. ISOLATED THUNDERSTORMS WILL END THIS
EVENING BUT A CHANCE OF THUNDERSTORMS WILL DEVELOP AGAIN SATURDAY
AFTERNOON. LOCAL MVFR CIGS ARE POSSIBLE NEAR SHOWERS AND
THUNDERSTORMS BUT ELSEWHERE VFR CONDITIONS WILL PREVAIL THROUGH THE
NEXT 24 HOURS.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  47  64  43  65 /  20  40  20  20
CTB  42  67  38  67 /  10  20  10  10
HLN  48  64  45  67 /  40  70  40  20
BZN  42  61  41  62 /  30  60  40  40
WEY  34  57  33  57 /  60  60  40  30
DLN  44  62  41  63 /  30  50  30  30
HVR  42  70  41  71 /  20  20  10  20
LWT  45  61  42  61 /  40  50  20  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



  [top]

000
FXUS65 KMSO 222051 CCA
AFDMSO

Area Forecast Discussion...CORRECTED
National Weather Service Missoula MT
251 PM MDT FRI MAY 22 2015

.DISCUSSION...

Showers and thunderstorms have sprung up across southwest Montana
and north central Idaho this afternoon. Most showers and storms
will remain south of I-90 through this evening, keeping northwest
Montana dry. Because steering flow aloft is weak, storms remain
relatively locked to the terrain, but will move slowly to the
southwest over time. Lightning, gusty winds, and brief periods of
heavy rain will be the primary threats from these storms. Small
hail could fall from the strongest cells, with storms over the
Camas Prairie in Idaho having the best chance of reaching this
strength. Showers will diminish quickly after sunset.

On Saturday, a weak weather disturbance will move from NE to SW
across southwest Montana and Lemhi & Idaho county Idaho. This
could lead to additional light rain in many of the same places
that saw rain Friday. Temperatures will be a few degrees cooler
than Friday, but remain near seasonal values. Sunday looks like
the driest day of the Memorial Day weekend with more seasonal
temperatures.

Models are coming into better alignment regarding a moist low
pressure system shifting over the northern Rockies Monday,
Tuesday, and possibly Wednesday. Note, the majority of the models
within the ECMWF and GFS ensembles actually show the low pressure
system a bit further south and hanging around longer than the
operational runs. Bottom line...a wetter period, with widespread
showers and a few thunderstorms, appears in store for north
central Idaho and western Montana Monday, Tuesday and maybe
Wednesday.


&&

.AVIATION...
Showers and thunderstorms have formed this afternoon across the
area. The best areas for continued storms will be at terminals
along and south of I-90, namely, KSMN, KBTM, and KGIC. KMSO will
be at the northern border of this area of concern, so it too could
see a shower or two later in the afternoon. Winds could be gusty
to 15-20 kts near showers, but should be 10 kts or less otherwise.
Thunderstorms, showers, and winds look to diminish around
23/0300z. Rain showers are again possible tomorrow afternoon.


&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

$$




000
FXUS65 KMSO 222051
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
251 PM MDT FRI MAY 22 2015

.DISCUSSION...

Showers and thunderstorms have sprung up across southwest Montana
and north central Idaho this afternoon. Most showers and storms
will remain south of I-90 through this evening, keeping northwest
Montana dry. Because steering flow aloft is weak, storms remain
relatively locked to the terrain, but will move slowly to the
southwest over time. Lightning, gusty winds, and brief periods of
heavy rain will be the primary threats from these storms. Small
hail could fall from the strongest cells, with storms over the
Camas Prairie in Idaho having the best chance of reaching this
strength. Showers will diminish quickly after sunset.

On Saturday, a weak weather disturbance will move from NE to SW
across southwest Montana and Lemhi & Idaho county Idaho. This
could lead to additional light rain in many of the same places
that saw rain Friday. Temperatures will be a few degrees cooler
than Friday, but remain near seasonal values. Sunday looks like
the driest day of the Memorial Day weekend with more seasonal
temperatures.

Models are coming into better alignment regarding a moist low
pressure system shifting over the northern Rockies Monday,
Tuesday, and possibly Wednesday. Note, the majority of the models
within the ECMWF and GFS ensembles actually show the low pressure
system a bit further south and hanging around longer than the
operational runs. Bottom line...a wetter period, with widespread
showers and a few thunderstorms, appears in store for north
central Idaho and western Montana Monday, Tuesday and maybe
Wednesday.


&&

.AVIATION...
Showers and thunderstorms have formed this afternoon across the
area. The best areas for continued storms will be at terminals
along and south of I-90, namely, KSMN, KBTM, and KGVL. KMSO will
be at the northern border of this area of concern, so it too could
see a shower or two later in the afternoon. Winds could be gusty
to 15-20 kts near showers, but should be 10 kts or less otherwise.
Thunderstorms, showers, and winds look to diminish around 23/0300z.
Rain showers are again possible tomorrow afternoon.


&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

$$



000
FXUS65 KMSO 222051
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
251 PM MDT FRI MAY 22 2015

.DISCUSSION...

Showers and thunderstorms have sprung up across southwest Montana
and north central Idaho this afternoon. Most showers and storms
will remain south of I-90 through this evening, keeping northwest
Montana dry. Because steering flow aloft is weak, storms remain
relatively locked to the terrain, but will move slowly to the
southwest over time. Lightning, gusty winds, and brief periods of
heavy rain will be the primary threats from these storms. Small
hail could fall from the strongest cells, with storms over the
Camas Prairie in Idaho having the best chance of reaching this
strength. Showers will diminish quickly after sunset.

On Saturday, a weak weather disturbance will move from NE to SW
across southwest Montana and Lemhi & Idaho county Idaho. This
could lead to additional light rain in many of the same places
that saw rain Friday. Temperatures will be a few degrees cooler
than Friday, but remain near seasonal values. Sunday looks like
the driest day of the Memorial Day weekend with more seasonal
temperatures.

Models are coming into better alignment regarding a moist low
pressure system shifting over the northern Rockies Monday,
Tuesday, and possibly Wednesday. Note, the majority of the models
within the ECMWF and GFS ensembles actually show the low pressure
system a bit further south and hanging around longer than the
operational runs. Bottom line...a wetter period, with widespread
showers and a few thunderstorms, appears in store for north
central Idaho and western Montana Monday, Tuesday and maybe
Wednesday.


&&

.AVIATION...
Showers and thunderstorms have formed this afternoon across the
area. The best areas for continued storms will be at terminals
along and south of I-90, namely, KSMN, KBTM, and KGVL. KMSO will
be at the northern border of this area of concern, so it too could
see a shower or two later in the afternoon. Winds could be gusty
to 15-20 kts near showers, but should be 10 kts or less otherwise.
Thunderstorms, showers, and winds look to diminish around 23/0300z.
Rain showers are again possible tomorrow afternoon.


&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

$$



000
FXUS65 KMSO 222051
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
251 PM MDT FRI MAY 22 2015

.DISCUSSION...

Showers and thunderstorms have sprung up across southwest Montana
and north central Idaho this afternoon. Most showers and storms
will remain south of I-90 through this evening, keeping northwest
Montana dry. Because steering flow aloft is weak, storms remain
relatively locked to the terrain, but will move slowly to the
southwest over time. Lightning, gusty winds, and brief periods of
heavy rain will be the primary threats from these storms. Small
hail could fall from the strongest cells, with storms over the
Camas Prairie in Idaho having the best chance of reaching this
strength. Showers will diminish quickly after sunset.

On Saturday, a weak weather disturbance will move from NE to SW
across southwest Montana and Lemhi & Idaho county Idaho. This
could lead to additional light rain in many of the same places
that saw rain Friday. Temperatures will be a few degrees cooler
than Friday, but remain near seasonal values. Sunday looks like
the driest day of the Memorial Day weekend with more seasonal
temperatures.

Models are coming into better alignment regarding a moist low
pressure system shifting over the northern Rockies Monday,
Tuesday, and possibly Wednesday. Note, the majority of the models
within the ECMWF and GFS ensembles actually show the low pressure
system a bit further south and hanging around longer than the
operational runs. Bottom line...a wetter period, with widespread
showers and a few thunderstorms, appears in store for north
central Idaho and western Montana Monday, Tuesday and maybe
Wednesday.


&&

.AVIATION...
Showers and thunderstorms have formed this afternoon across the
area. The best areas for continued storms will be at terminals
along and south of I-90, namely, KSMN, KBTM, and KGVL. KMSO will
be at the northern border of this area of concern, so it too could
see a shower or two later in the afternoon. Winds could be gusty
to 15-20 kts near showers, but should be 10 kts or less otherwise.
Thunderstorms, showers, and winds look to diminish around 23/0300z.
Rain showers are again possible tomorrow afternoon.


&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

$$



000
FXUS65 KMSO 222051
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
251 PM MDT FRI MAY 22 2015

.DISCUSSION...

Showers and thunderstorms have sprung up across southwest Montana
and north central Idaho this afternoon. Most showers and storms
will remain south of I-90 through this evening, keeping northwest
Montana dry. Because steering flow aloft is weak, storms remain
relatively locked to the terrain, but will move slowly to the
southwest over time. Lightning, gusty winds, and brief periods of
heavy rain will be the primary threats from these storms. Small
hail could fall from the strongest cells, with storms over the
Camas Prairie in Idaho having the best chance of reaching this
strength. Showers will diminish quickly after sunset.

On Saturday, a weak weather disturbance will move from NE to SW
across southwest Montana and Lemhi & Idaho county Idaho. This
could lead to additional light rain in many of the same places
that saw rain Friday. Temperatures will be a few degrees cooler
than Friday, but remain near seasonal values. Sunday looks like
the driest day of the Memorial Day weekend with more seasonal
temperatures.

Models are coming into better alignment regarding a moist low
pressure system shifting over the northern Rockies Monday,
Tuesday, and possibly Wednesday. Note, the majority of the models
within the ECMWF and GFS ensembles actually show the low pressure
system a bit further south and hanging around longer than the
operational runs. Bottom line...a wetter period, with widespread
showers and a few thunderstorms, appears in store for north
central Idaho and western Montana Monday, Tuesday and maybe
Wednesday.


&&

.AVIATION...
Showers and thunderstorms have formed this afternoon across the
area. The best areas for continued storms will be at terminals
along and south of I-90, namely, KSMN, KBTM, and KGVL. KMSO will
be at the northern border of this area of concern, so it too could
see a shower or two later in the afternoon. Winds could be gusty
to 15-20 kts near showers, but should be 10 kts or less otherwise.
Thunderstorms, showers, and winds look to diminish around 23/0300z.
Rain showers are again possible tomorrow afternoon.


&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

$$



000
FXUS65 KBYZ 222040
AFDBYZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
240 PM MDT FRI MAY 22 2015

.SHORT TERM...VALID FOR SAT AND SUN...

AN UPPER LOW MOVING NORTHEAST OUT OF COLORADO THIS AFTERNOON IS
RESULTING IN AREAS OF RAIN ACROSS WESTERN NEBRASKA AND SOUTHEAST
WYOMING. SOME OF THIS PRECIP IS SLOWLY SHIFTING NORTH RESULTING IN
ISOLATED TO SCATTERED SHOWERS ACROSS NORTHERN WYOMING INTO
SOUTHERN/SOUTHEASTERN MONTANA. THERE IS ANOTHER UPPER LOW THAT IS
CURRENTLY MOVING OUT OF SOUTHERN CALIFORNIA INTO THE FOUR CORNERS
AREA. THESE TWO LOWS ARE WRAPPING MOISTURE WEST AND NORTH ACROSS
THE GREAT BASIN AREA. LIGHTING DATA IS SHOWING THUNDERSTORMS
POPPING UP ALL ACROSS THE WEST EAST OF THE ROCKIES. WATER VAPOR
IMAGERY ALONG WITH THE LIGHTING DATA LOOK TO BE WHAT WE WOULD
TYPICALLY SEE DURING THE MONSOON SEASON OF LATE JULY/EARLY AUGUST.

THESE LOWS WILL SLOWLY MOVE EAST AND NORTHEAST THROUGH THE
WEEKEND WITH PIECES OF ENERGY GETTING EJECTED ACROSS OUR AREA. AS
A RESULT...WILL KEEP A CHANCE FOR SHOWERS AND ISOLATED
THUNDERSTORMS IN THE FORECAST THROUGH THE WEEKEND. AS THE UPPER
LOW OVER THE FOUR CORNERS REGION MOVES INTO THE WESTERN HIGH
PLAINS SUNDAY INTO SUNDAY NIGHT...IT WILL WRAP MOISTURE AROUND THE
BACK SIDE OF IT ACROSS SOUTHEAST MONTANA BRINGING THE LIKELIHOOD OF
NUMEROUS SHOWERS OR POSSIBLY A LIGHT STEADY RAIN. AS A RESULT...I
INCREASED POPS TO LIKELY FOR OUR FAR SOUTHEAST COUNTIES LATE
SATURDAY NIGHT INTO EARLY MONDAY MORNING.

ELSEWHERE ACROSS THE FORECAST AREA...SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS CAN BE EXPECTED THROUGH THE WEEKEND. GIVEN
THE LIGHT WINDS ALOFT/LITTLE SHEAR...THUNDERSTORMS ARE NOT
EXPECTED TO BE SEVERE OR EVEN STRONG BUT THEY MAY PRODUCE SOME
BRIEF HEAVY RAIN. WITH THE EXCEPTION OF FAR SOUTHEAST MONTANA
SUNDAY...THE WEEKEND FOR THE MAJORITY OF OUR AREA IS NOT EXPECTED
TO BE A WASHOUT. TEMPEATURES WILL BE BELOW NORMAL IN THE LOWER 60S
FOR MOST AREAS BUT NOT AS COOL AS THE PAST COUPLE OF WEEKENDS.
HOOLEY

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

A BROAD TROUGH WILL BE OVER THE EASTERN HALF OF THE NORTHERN AND
CENTRAL ROCKIES MONDAY INTO TUESDAY. THE FLOW ALOFT WILL BE WEAK
AS THE MAJORITY OF THE JET ENERGY WILL BE TO OUR NORTH AND SOUTH
OF OUR FORECAST AREA. THERE WILL BE ENOUGH INSTABILITY AROUND TO
WARRANT A CHANCE FOR A SHOWER OR THUNDERSTORM MONDAY AND TUESDAY.
850MB TEMPERATURES WILL BEGIN TO WARM FROM WEST TO EAST MONDAY AND
WITH READINGS AROUND 15-18C SPREADING EAST ACROSS THE ENTIRE AREA
TUESDAY RESULTING IN TEMPERATURES WARMING TO NORMAL TO SLIGHTLY
ABOVE NORMAL VALUES.

MODELS BRING AN UPPER LOW OVER THE PACIFIC NORTHWEST EASTWARD
ACROSS MONTANA WEDNESDAY INTO THURSDAY RESULTING IN INCREASING
CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS. A COLD FRONT IS
PROGGED TO DROP SOUTH ACROSS THE FORECAST AREA THURSDAY NIGHT INTO
FRIDAY KEEPING SHOWER AND THUNDERSTORM CHANCES IN THE FORECAST.
TEMPERATURES LOOK TO BE AROUND NORMAL THROUGH THE PERIOD UNTIL
FRIDAY WHEN READINGS WILL COOL SLIGHTLY BEHIND THE COLD FRONT.
HOOLEY

&&

.AVIATION...

ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL PERSIST INTO
THE MID/LATE EVENING HOURS TONIGHT. LOCAL MVFR OR LOWER CONDITIONS
CAN BE EXPECTED NEAR THIS ACTIVITY WITH MODERATE RAINFALL RATES
AND SLOW STORM MOTIONS. RESIDUAL CLOUD COVER WILL PERSIST ONCE
CONVECTION DISSIPATES BUT CEILINGS SHOULD REMAIN VFR. AS HAS BEEN
THE CASE FOR THE PAST FEW DAYS EASTERLY WINDS COULD RESULT IN
LOCALIZED FOG/STRATUS DEVELOPMENT AROUND SUNRISE JUST ABOUT
ANYWHERE IN THE FORECAST AREA. ANY DEVELOPMENT WILL BE BRIEF BUT
COULD RESULT IN 1/2SM VISIBILITY. CHAMBERS
&&

.PRELIMINARY POINT TEMP/POPS...

    SAT     SUN     MON     TUE     WED     THU     FRI
-----------------------------------------------------------
BIL 046/063 045/060 045/070 047/072 049/071 050/071 048/066
    23/T    23/T    32/T    23/T    33/T    33/T    33/T
LVM 045/061 041/061 039/067 043/068 044/066 045/069 043/065
    36/T    33/T    33/T    34/T    44/T    43/T    33/T
HDN 045/065 046/061 045/071 046/074 049/074 049/074 048/069
    23/T    33/T    32/T    23/T    33/T    33/T    33/T
MLS 047/064 045/062 047/067 046/073 050/072 050/071 049/067
    23/T    44/T    44/T    42/T    23/T    33/T    33/T
4BQ 043/059 046/058 046/065 045/072 049/071 049/070 048/068
    26/T    67/T    43/T    33/T    33/T    33/T    33/T
BHK 043/058 045/060 045/065 043/069 047/070 048/069 046/066
    26/T    67/T    66/T    63/T    33/T    33/T    33/T
SHR 045/059 043/058 042/065 042/070 046/070 046/069 045/068
    25/T    46/T    33/T    34/T    43/T    33/T    33/T

&&

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

&&

$$
WEATHER.GOV/BILLINGS




000
FXUS65 KBYZ 222040
AFDBYZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
240 PM MDT FRI MAY 22 2015

.SHORT TERM...VALID FOR SAT AND SUN...

AN UPPER LOW MOVING NORTHEAST OUT OF COLORADO THIS AFTERNOON IS
RESULTING IN AREAS OF RAIN ACROSS WESTERN NEBRASKA AND SOUTHEAST
WYOMING. SOME OF THIS PRECIP IS SLOWLY SHIFTING NORTH RESULTING IN
ISOLATED TO SCATTERED SHOWERS ACROSS NORTHERN WYOMING INTO
SOUTHERN/SOUTHEASTERN MONTANA. THERE IS ANOTHER UPPER LOW THAT IS
CURRENTLY MOVING OUT OF SOUTHERN CALIFORNIA INTO THE FOUR CORNERS
AREA. THESE TWO LOWS ARE WRAPPING MOISTURE WEST AND NORTH ACROSS
THE GREAT BASIN AREA. LIGHTING DATA IS SHOWING THUNDERSTORMS
POPPING UP ALL ACROSS THE WEST EAST OF THE ROCKIES. WATER VAPOR
IMAGERY ALONG WITH THE LIGHTING DATA LOOK TO BE WHAT WE WOULD
TYPICALLY SEE DURING THE MONSOON SEASON OF LATE JULY/EARLY AUGUST.

THESE LOWS WILL SLOWLY MOVE EAST AND NORTHEAST THROUGH THE
WEEKEND WITH PIECES OF ENERGY GETTING EJECTED ACROSS OUR AREA. AS
A RESULT...WILL KEEP A CHANCE FOR SHOWERS AND ISOLATED
THUNDERSTORMS IN THE FORECAST THROUGH THE WEEKEND. AS THE UPPER
LOW OVER THE FOUR CORNERS REGION MOVES INTO THE WESTERN HIGH
PLAINS SUNDAY INTO SUNDAY NIGHT...IT WILL WRAP MOISTURE AROUND THE
BACK SIDE OF IT ACROSS SOUTHEAST MONTANA BRINGING THE LIKELIHOOD OF
NUMEROUS SHOWERS OR POSSIBLY A LIGHT STEADY RAIN. AS A RESULT...I
INCREASED POPS TO LIKELY FOR OUR FAR SOUTHEAST COUNTIES LATE
SATURDAY NIGHT INTO EARLY MONDAY MORNING.

ELSEWHERE ACROSS THE FORECAST AREA...SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS CAN BE EXPECTED THROUGH THE WEEKEND. GIVEN
THE LIGHT WINDS ALOFT/LITTLE SHEAR...THUNDERSTORMS ARE NOT
EXPECTED TO BE SEVERE OR EVEN STRONG BUT THEY MAY PRODUCE SOME
BRIEF HEAVY RAIN. WITH THE EXCEPTION OF FAR SOUTHEAST MONTANA
SUNDAY...THE WEEKEND FOR THE MAJORITY OF OUR AREA IS NOT EXPECTED
TO BE A WASHOUT. TEMPEATURES WILL BE BELOW NORMAL IN THE LOWER 60S
FOR MOST AREAS BUT NOT AS COOL AS THE PAST COUPLE OF WEEKENDS.
HOOLEY

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

A BROAD TROUGH WILL BE OVER THE EASTERN HALF OF THE NORTHERN AND
CENTRAL ROCKIES MONDAY INTO TUESDAY. THE FLOW ALOFT WILL BE WEAK
AS THE MAJORITY OF THE JET ENERGY WILL BE TO OUR NORTH AND SOUTH
OF OUR FORECAST AREA. THERE WILL BE ENOUGH INSTABILITY AROUND TO
WARRANT A CHANCE FOR A SHOWER OR THUNDERSTORM MONDAY AND TUESDAY.
850MB TEMPERATURES WILL BEGIN TO WARM FROM WEST TO EAST MONDAY AND
WITH READINGS AROUND 15-18C SPREADING EAST ACROSS THE ENTIRE AREA
TUESDAY RESULTING IN TEMPERATURES WARMING TO NORMAL TO SLIGHTLY
ABOVE NORMAL VALUES.

MODELS BRING AN UPPER LOW OVER THE PACIFIC NORTHWEST EASTWARD
ACROSS MONTANA WEDNESDAY INTO THURSDAY RESULTING IN INCREASING
CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS. A COLD FRONT IS
PROGGED TO DROP SOUTH ACROSS THE FORECAST AREA THURSDAY NIGHT INTO
FRIDAY KEEPING SHOWER AND THUNDERSTORM CHANCES IN THE FORECAST.
TEMPERATURES LOOK TO BE AROUND NORMAL THROUGH THE PERIOD UNTIL
FRIDAY WHEN READINGS WILL COOL SLIGHTLY BEHIND THE COLD FRONT.
HOOLEY

&&

.AVIATION...

ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL PERSIST INTO
THE MID/LATE EVENING HOURS TONIGHT. LOCAL MVFR OR LOWER CONDITIONS
CAN BE EXPECTED NEAR THIS ACTIVITY WITH MODERATE RAINFALL RATES
AND SLOW STORM MOTIONS. RESIDUAL CLOUD COVER WILL PERSIST ONCE
CONVECTION DISSIPATES BUT CEILINGS SHOULD REMAIN VFR. AS HAS BEEN
THE CASE FOR THE PAST FEW DAYS EASTERLY WINDS COULD RESULT IN
LOCALIZED FOG/STRATUS DEVELOPMENT AROUND SUNRISE JUST ABOUT
ANYWHERE IN THE FORECAST AREA. ANY DEVELOPMENT WILL BE BRIEF BUT
COULD RESULT IN 1/2SM VISIBILITY. CHAMBERS
&&

.PRELIMINARY POINT TEMP/POPS...

    SAT     SUN     MON     TUE     WED     THU     FRI
-----------------------------------------------------------
BIL 046/063 045/060 045/070 047/072 049/071 050/071 048/066
    23/T    23/T    32/T    23/T    33/T    33/T    33/T
LVM 045/061 041/061 039/067 043/068 044/066 045/069 043/065
    36/T    33/T    33/T    34/T    44/T    43/T    33/T
HDN 045/065 046/061 045/071 046/074 049/074 049/074 048/069
    23/T    33/T    32/T    23/T    33/T    33/T    33/T
MLS 047/064 045/062 047/067 046/073 050/072 050/071 049/067
    23/T    44/T    44/T    42/T    23/T    33/T    33/T
4BQ 043/059 046/058 046/065 045/072 049/071 049/070 048/068
    26/T    67/T    43/T    33/T    33/T    33/T    33/T
BHK 043/058 045/060 045/065 043/069 047/070 048/069 046/066
    26/T    67/T    66/T    63/T    33/T    33/T    33/T
SHR 045/059 043/058 042/065 042/070 046/070 046/069 045/068
    25/T    46/T    33/T    34/T    43/T    33/T    33/T

&&

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

&&

$$
WEATHER.GOV/BILLINGS




000
FXUS65 KBYZ 222040
AFDBYZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
240 PM MDT FRI MAY 22 2015

.SHORT TERM...VALID FOR SAT AND SUN...

AN UPPER LOW MOVING NORTHEAST OUT OF COLORADO THIS AFTERNOON IS
RESULTING IN AREAS OF RAIN ACROSS WESTERN NEBRASKA AND SOUTHEAST
WYOMING. SOME OF THIS PRECIP IS SLOWLY SHIFTING NORTH RESULTING IN
ISOLATED TO SCATTERED SHOWERS ACROSS NORTHERN WYOMING INTO
SOUTHERN/SOUTHEASTERN MONTANA. THERE IS ANOTHER UPPER LOW THAT IS
CURRENTLY MOVING OUT OF SOUTHERN CALIFORNIA INTO THE FOUR CORNERS
AREA. THESE TWO LOWS ARE WRAPPING MOISTURE WEST AND NORTH ACROSS
THE GREAT BASIN AREA. LIGHTING DATA IS SHOWING THUNDERSTORMS
POPPING UP ALL ACROSS THE WEST EAST OF THE ROCKIES. WATER VAPOR
IMAGERY ALONG WITH THE LIGHTING DATA LOOK TO BE WHAT WE WOULD
TYPICALLY SEE DURING THE MONSOON SEASON OF LATE JULY/EARLY AUGUST.

THESE LOWS WILL SLOWLY MOVE EAST AND NORTHEAST THROUGH THE
WEEKEND WITH PIECES OF ENERGY GETTING EJECTED ACROSS OUR AREA. AS
A RESULT...WILL KEEP A CHANCE FOR SHOWERS AND ISOLATED
THUNDERSTORMS IN THE FORECAST THROUGH THE WEEKEND. AS THE UPPER
LOW OVER THE FOUR CORNERS REGION MOVES INTO THE WESTERN HIGH
PLAINS SUNDAY INTO SUNDAY NIGHT...IT WILL WRAP MOISTURE AROUND THE
BACK SIDE OF IT ACROSS SOUTHEAST MONTANA BRINGING THE LIKELIHOOD OF
NUMEROUS SHOWERS OR POSSIBLY A LIGHT STEADY RAIN. AS A RESULT...I
INCREASED POPS TO LIKELY FOR OUR FAR SOUTHEAST COUNTIES LATE
SATURDAY NIGHT INTO EARLY MONDAY MORNING.

ELSEWHERE ACROSS THE FORECAST AREA...SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS CAN BE EXPECTED THROUGH THE WEEKEND. GIVEN
THE LIGHT WINDS ALOFT/LITTLE SHEAR...THUNDERSTORMS ARE NOT
EXPECTED TO BE SEVERE OR EVEN STRONG BUT THEY MAY PRODUCE SOME
BRIEF HEAVY RAIN. WITH THE EXCEPTION OF FAR SOUTHEAST MONTANA
SUNDAY...THE WEEKEND FOR THE MAJORITY OF OUR AREA IS NOT EXPECTED
TO BE A WASHOUT. TEMPEATURES WILL BE BELOW NORMAL IN THE LOWER 60S
FOR MOST AREAS BUT NOT AS COOL AS THE PAST COUPLE OF WEEKENDS.
HOOLEY

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

A BROAD TROUGH WILL BE OVER THE EASTERN HALF OF THE NORTHERN AND
CENTRAL ROCKIES MONDAY INTO TUESDAY. THE FLOW ALOFT WILL BE WEAK
AS THE MAJORITY OF THE JET ENERGY WILL BE TO OUR NORTH AND SOUTH
OF OUR FORECAST AREA. THERE WILL BE ENOUGH INSTABILITY AROUND TO
WARRANT A CHANCE FOR A SHOWER OR THUNDERSTORM MONDAY AND TUESDAY.
850MB TEMPERATURES WILL BEGIN TO WARM FROM WEST TO EAST MONDAY AND
WITH READINGS AROUND 15-18C SPREADING EAST ACROSS THE ENTIRE AREA
TUESDAY RESULTING IN TEMPERATURES WARMING TO NORMAL TO SLIGHTLY
ABOVE NORMAL VALUES.

MODELS BRING AN UPPER LOW OVER THE PACIFIC NORTHWEST EASTWARD
ACROSS MONTANA WEDNESDAY INTO THURSDAY RESULTING IN INCREASING
CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS. A COLD FRONT IS
PROGGED TO DROP SOUTH ACROSS THE FORECAST AREA THURSDAY NIGHT INTO
FRIDAY KEEPING SHOWER AND THUNDERSTORM CHANCES IN THE FORECAST.
TEMPERATURES LOOK TO BE AROUND NORMAL THROUGH THE PERIOD UNTIL
FRIDAY WHEN READINGS WILL COOL SLIGHTLY BEHIND THE COLD FRONT.
HOOLEY

&&

.AVIATION...

ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL PERSIST INTO
THE MID/LATE EVENING HOURS TONIGHT. LOCAL MVFR OR LOWER CONDITIONS
CAN BE EXPECTED NEAR THIS ACTIVITY WITH MODERATE RAINFALL RATES
AND SLOW STORM MOTIONS. RESIDUAL CLOUD COVER WILL PERSIST ONCE
CONVECTION DISSIPATES BUT CEILINGS SHOULD REMAIN VFR. AS HAS BEEN
THE CASE FOR THE PAST FEW DAYS EASTERLY WINDS COULD RESULT IN
LOCALIZED FOG/STRATUS DEVELOPMENT AROUND SUNRISE JUST ABOUT
ANYWHERE IN THE FORECAST AREA. ANY DEVELOPMENT WILL BE BRIEF BUT
COULD RESULT IN 1/2SM VISIBILITY. CHAMBERS
&&

.PRELIMINARY POINT TEMP/POPS...

    SAT     SUN     MON     TUE     WED     THU     FRI
-----------------------------------------------------------
BIL 046/063 045/060 045/070 047/072 049/071 050/071 048/066
    23/T    23/T    32/T    23/T    33/T    33/T    33/T
LVM 045/061 041/061 039/067 043/068 044/066 045/069 043/065
    36/T    33/T    33/T    34/T    44/T    43/T    33/T
HDN 045/065 046/061 045/071 046/074 049/074 049/074 048/069
    23/T    33/T    32/T    23/T    33/T    33/T    33/T
MLS 047/064 045/062 047/067 046/073 050/072 050/071 049/067
    23/T    44/T    44/T    42/T    23/T    33/T    33/T
4BQ 043/059 046/058 046/065 045/072 049/071 049/070 048/068
    26/T    67/T    43/T    33/T    33/T    33/T    33/T
BHK 043/058 045/060 045/065 043/069 047/070 048/069 046/066
    26/T    67/T    66/T    63/T    33/T    33/T    33/T
SHR 045/059 043/058 042/065 042/070 046/070 046/069 045/068
    25/T    46/T    33/T    34/T    43/T    33/T    33/T

&&

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

&&

$$
WEATHER.GOV/BILLINGS




000
FXUS65 KBYZ 222040
AFDBYZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
240 PM MDT FRI MAY 22 2015

.SHORT TERM...VALID FOR SAT AND SUN...

AN UPPER LOW MOVING NORTHEAST OUT OF COLORADO THIS AFTERNOON IS
RESULTING IN AREAS OF RAIN ACROSS WESTERN NEBRASKA AND SOUTHEAST
WYOMING. SOME OF THIS PRECIP IS SLOWLY SHIFTING NORTH RESULTING IN
ISOLATED TO SCATTERED SHOWERS ACROSS NORTHERN WYOMING INTO
SOUTHERN/SOUTHEASTERN MONTANA. THERE IS ANOTHER UPPER LOW THAT IS
CURRENTLY MOVING OUT OF SOUTHERN CALIFORNIA INTO THE FOUR CORNERS
AREA. THESE TWO LOWS ARE WRAPPING MOISTURE WEST AND NORTH ACROSS
THE GREAT BASIN AREA. LIGHTING DATA IS SHOWING THUNDERSTORMS
POPPING UP ALL ACROSS THE WEST EAST OF THE ROCKIES. WATER VAPOR
IMAGERY ALONG WITH THE LIGHTING DATA LOOK TO BE WHAT WE WOULD
TYPICALLY SEE DURING THE MONSOON SEASON OF LATE JULY/EARLY AUGUST.

THESE LOWS WILL SLOWLY MOVE EAST AND NORTHEAST THROUGH THE
WEEKEND WITH PIECES OF ENERGY GETTING EJECTED ACROSS OUR AREA. AS
A RESULT...WILL KEEP A CHANCE FOR SHOWERS AND ISOLATED
THUNDERSTORMS IN THE FORECAST THROUGH THE WEEKEND. AS THE UPPER
LOW OVER THE FOUR CORNERS REGION MOVES INTO THE WESTERN HIGH
PLAINS SUNDAY INTO SUNDAY NIGHT...IT WILL WRAP MOISTURE AROUND THE
BACK SIDE OF IT ACROSS SOUTHEAST MONTANA BRINGING THE LIKELIHOOD OF
NUMEROUS SHOWERS OR POSSIBLY A LIGHT STEADY RAIN. AS A RESULT...I
INCREASED POPS TO LIKELY FOR OUR FAR SOUTHEAST COUNTIES LATE
SATURDAY NIGHT INTO EARLY MONDAY MORNING.

ELSEWHERE ACROSS THE FORECAST AREA...SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS CAN BE EXPECTED THROUGH THE WEEKEND. GIVEN
THE LIGHT WINDS ALOFT/LITTLE SHEAR...THUNDERSTORMS ARE NOT
EXPECTED TO BE SEVERE OR EVEN STRONG BUT THEY MAY PRODUCE SOME
BRIEF HEAVY RAIN. WITH THE EXCEPTION OF FAR SOUTHEAST MONTANA
SUNDAY...THE WEEKEND FOR THE MAJORITY OF OUR AREA IS NOT EXPECTED
TO BE A WASHOUT. TEMPEATURES WILL BE BELOW NORMAL IN THE LOWER 60S
FOR MOST AREAS BUT NOT AS COOL AS THE PAST COUPLE OF WEEKENDS.
HOOLEY

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

A BROAD TROUGH WILL BE OVER THE EASTERN HALF OF THE NORTHERN AND
CENTRAL ROCKIES MONDAY INTO TUESDAY. THE FLOW ALOFT WILL BE WEAK
AS THE MAJORITY OF THE JET ENERGY WILL BE TO OUR NORTH AND SOUTH
OF OUR FORECAST AREA. THERE WILL BE ENOUGH INSTABILITY AROUND TO
WARRANT A CHANCE FOR A SHOWER OR THUNDERSTORM MONDAY AND TUESDAY.
850MB TEMPERATURES WILL BEGIN TO WARM FROM WEST TO EAST MONDAY AND
WITH READINGS AROUND 15-18C SPREADING EAST ACROSS THE ENTIRE AREA
TUESDAY RESULTING IN TEMPERATURES WARMING TO NORMAL TO SLIGHTLY
ABOVE NORMAL VALUES.

MODELS BRING AN UPPER LOW OVER THE PACIFIC NORTHWEST EASTWARD
ACROSS MONTANA WEDNESDAY INTO THURSDAY RESULTING IN INCREASING
CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS. A COLD FRONT IS
PROGGED TO DROP SOUTH ACROSS THE FORECAST AREA THURSDAY NIGHT INTO
FRIDAY KEEPING SHOWER AND THUNDERSTORM CHANCES IN THE FORECAST.
TEMPERATURES LOOK TO BE AROUND NORMAL THROUGH THE PERIOD UNTIL
FRIDAY WHEN READINGS WILL COOL SLIGHTLY BEHIND THE COLD FRONT.
HOOLEY

&&

.AVIATION...

ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL PERSIST INTO
THE MID/LATE EVENING HOURS TONIGHT. LOCAL MVFR OR LOWER CONDITIONS
CAN BE EXPECTED NEAR THIS ACTIVITY WITH MODERATE RAINFALL RATES
AND SLOW STORM MOTIONS. RESIDUAL CLOUD COVER WILL PERSIST ONCE
CONVECTION DISSIPATES BUT CEILINGS SHOULD REMAIN VFR. AS HAS BEEN
THE CASE FOR THE PAST FEW DAYS EASTERLY WINDS COULD RESULT IN
LOCALIZED FOG/STRATUS DEVELOPMENT AROUND SUNRISE JUST ABOUT
ANYWHERE IN THE FORECAST AREA. ANY DEVELOPMENT WILL BE BRIEF BUT
COULD RESULT IN 1/2SM VISIBILITY. CHAMBERS
&&

.PRELIMINARY POINT TEMP/POPS...

    SAT     SUN     MON     TUE     WED     THU     FRI
-----------------------------------------------------------
BIL 046/063 045/060 045/070 047/072 049/071 050/071 048/066
    23/T    23/T    32/T    23/T    33/T    33/T    33/T
LVM 045/061 041/061 039/067 043/068 044/066 045/069 043/065
    36/T    33/T    33/T    34/T    44/T    43/T    33/T
HDN 045/065 046/061 045/071 046/074 049/074 049/074 048/069
    23/T    33/T    32/T    23/T    33/T    33/T    33/T
MLS 047/064 045/062 047/067 046/073 050/072 050/071 049/067
    23/T    44/T    44/T    42/T    23/T    33/T    33/T
4BQ 043/059 046/058 046/065 045/072 049/071 049/070 048/068
    26/T    67/T    43/T    33/T    33/T    33/T    33/T
BHK 043/058 045/060 045/065 043/069 047/070 048/069 046/066
    26/T    67/T    66/T    63/T    33/T    33/T    33/T
SHR 045/059 043/058 042/065 042/070 046/070 046/069 045/068
    25/T    46/T    33/T    34/T    43/T    33/T    33/T

&&

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

&&

$$
WEATHER.GOV/BILLINGS




000
FXUS65 KTFX 222013
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
213 PM MDT FRI MAY 22 2015

.DISCUSSION...THIS AFTERNOON THROUGH MEMORIAL DAY AFTERNOON.
CURRENT RADAR/SATELLITE IMAGERY SHOWING SCATTERED SHOWERS AND A FEW
SMALL THUNDERSTORMS DEVELOPING MAINLY FROM THE LITTLE BELT AND SNOWY
MTNS SOUTH TO THE MT/ID BORDER.  EXPECT PRECIPITATION COVERAGE TO
INCREASE OVER THE SOUTHWEST COUNTIES AND EXTEND INTO PARTS OF
CASCADE/CHOUTEAU/FERGUS/JUDITH BASIN COUNTIES BY LATE AFTN AS
ADDITIONAL MOISTURE ARRIVES FROM IDAHO/WYOMING.  MOISTURE PUSH IS
DRIVEN BY A SLOW-MOVING UPPER-LEVEL LOW PRESSURE AREA PRESENTLY
CENTERED AT THE CA/NV/AZ BORDER.  FORECAST MODELS REMAIN IN VERY
GOOD AGREEMENT THAT THE LOW WILL TRACK GRADUALLY TO THE NORTHEAST
THROUGH THE GREAT BASIN OVER THE WEEKEND, REACHING EASTERN WYOMING
BY MIDDAY SUNDAY.  AS IT MOVES, EAST-SOUTHEAST WINDS ON THE
FRONTSIDE OF THE LOW`S CIRCULATION WILL BRING BOTH PACIFIC AND SOME
GULF OF MEXICO MOISTURE INTO MT, PRODUCING SCATTERED SHOWERS AND
THUNDERSTORMS EACH AFTERNOON AND EVENING THROUGH SUNDAY. NO STRONG
OR SEVERE STORMS ARE EXPECTED AT THIS TIME, AS INSTABILITY AND WIND
SHEAR PARAMETERS ARE FORECAST TO BE WEAK FOR THE NEXT COUPLE DAYS.
CONVECTIVE ACTIVITY WILL DISSIPATE OVER MOST OF THE FORECAST AREA
EACH EVENING NEAR/AFTER SUNSET.

LATEST MODELS ARE ALSO INDICATING A BETTER CHANCE OF SHORT-TERM DRY
CONDITIONS ON MONDAY AS OUR REGION WILL BE BETWEEN THE EXITING
WEEKEND WEATHER SYSTEM AND THE NEXT SHORTWAVE TROF MOVING INTO THE
PACIFIC NORTHWEST. ISOLATED SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE ALONG THE ROCKY MTN FRONT AND PARTS OF SOUTHWEST MT MON
AFTN/EVE AS THE TROF TAPS INTO RESIDUAL MOISTURE OVER WESTERN MT,
WHILE LOCATIONS GENERALLY ALONG/EAST OF THE INTERSTATE 15 CORRIDOR
REMAIN PRECIP FREE.
WARANAUSKAS


MONDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT
IN A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO
MIDWEEK. THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED
MONDAY NIGHT THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH
THEIR FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER
LOW NEAR VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS
IT MOVES INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER
LOW SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON
FRIDAY. DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR
PRECIPITATION FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM
TUESDAY ON OF SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS
THE CANADIAN BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED
THUNDERSTORMS DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO
NOT ANTICIPATE ANY SEVERE STORMS AT THIS TIME.
BLANK


&&

.AVIATION...
UPDATED 1125Z.
VFR CONDITIONS WILL CONTINUE TO PREVAIL FOR AREAS NORTH OF GREAT
FALLS THROUGH MUCH OF THE PERIOD. GENERALLY SOUTH OF A GREAT FALLS
TO LEWISTOWN LINE...EXPECT ISOLATED/SCATTERED SHOWERS/THUNDERSTORMS.
THE THUNDERSTORMS WILL BE MORE NUMEROUS SOUTH OF I90. MOST STORMS
WILL DIMINISH BY 03Z SAT BUT SCATTERED SHOWERS WILL CONTINUE OVER
CENTRAL MT THRU SAT MORNING. MVFR CONDITIONS ARE POSSIBLE IN/NEAR
ANY THUNDERSTORMS. BRUSDA

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  47  64  43  65 /  20  40  20  20
CTB  42  67  38  67 /  10  20  10  10
HLN  48  64  45  67 /  40  70  40  20
BZN  42  61  41  62 /  30  60  40  40
WEY  34  57  33  57 /  60  60  40  30
DLN  44  62  41  63 /  30  50  30  30
HVR  42  70  41  71 /  20  20  10  20
LWT  45  61  42  61 /  40  50  20  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 222013
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
213 PM MDT FRI MAY 22 2015

.DISCUSSION...THIS AFTERNOON THROUGH MEMORIAL DAY AFTERNOON.
CURRENT RADAR/SATELLITE IMAGERY SHOWING SCATTERED SHOWERS AND A FEW
SMALL THUNDERSTORMS DEVELOPING MAINLY FROM THE LITTLE BELT AND SNOWY
MTNS SOUTH TO THE MT/ID BORDER.  EXPECT PRECIPITATION COVERAGE TO
INCREASE OVER THE SOUTHWEST COUNTIES AND EXTEND INTO PARTS OF
CASCADE/CHOUTEAU/FERGUS/JUDITH BASIN COUNTIES BY LATE AFTN AS
ADDITIONAL MOISTURE ARRIVES FROM IDAHO/WYOMING.  MOISTURE PUSH IS
DRIVEN BY A SLOW-MOVING UPPER-LEVEL LOW PRESSURE AREA PRESENTLY
CENTERED AT THE CA/NV/AZ BORDER.  FORECAST MODELS REMAIN IN VERY
GOOD AGREEMENT THAT THE LOW WILL TRACK GRADUALLY TO THE NORTHEAST
THROUGH THE GREAT BASIN OVER THE WEEKEND, REACHING EASTERN WYOMING
BY MIDDAY SUNDAY.  AS IT MOVES, EAST-SOUTHEAST WINDS ON THE
FRONTSIDE OF THE LOW`S CIRCULATION WILL BRING BOTH PACIFIC AND SOME
GULF OF MEXICO MOISTURE INTO MT, PRODUCING SCATTERED SHOWERS AND
THUNDERSTORMS EACH AFTERNOON AND EVENING THROUGH SUNDAY. NO STRONG
OR SEVERE STORMS ARE EXPECTED AT THIS TIME, AS INSTABILITY AND WIND
SHEAR PARAMETERS ARE FORECAST TO BE WEAK FOR THE NEXT COUPLE DAYS.
CONVECTIVE ACTIVITY WILL DISSIPATE OVER MOST OF THE FORECAST AREA
EACH EVENING NEAR/AFTER SUNSET.

LATEST MODELS ARE ALSO INDICATING A BETTER CHANCE OF SHORT-TERM DRY
CONDITIONS ON MONDAY AS OUR REGION WILL BE BETWEEN THE EXITING
WEEKEND WEATHER SYSTEM AND THE NEXT SHORTWAVE TROF MOVING INTO THE
PACIFIC NORTHWEST. ISOLATED SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE ALONG THE ROCKY MTN FRONT AND PARTS OF SOUTHWEST MT MON
AFTN/EVE AS THE TROF TAPS INTO RESIDUAL MOISTURE OVER WESTERN MT,
WHILE LOCATIONS GENERALLY ALONG/EAST OF THE INTERSTATE 15 CORRIDOR
REMAIN PRECIP FREE.
WARANAUSKAS


MONDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT
IN A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO
MIDWEEK. THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED
MONDAY NIGHT THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH
THEIR FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER
LOW NEAR VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS
IT MOVES INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER
LOW SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON
FRIDAY. DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR
PRECIPITATION FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM
TUESDAY ON OF SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS
THE CANADIAN BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED
THUNDERSTORMS DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO
NOT ANTICIPATE ANY SEVERE STORMS AT THIS TIME.
BLANK


&&

.AVIATION...
UPDATED 1125Z.
VFR CONDITIONS WILL CONTINUE TO PREVAIL FOR AREAS NORTH OF GREAT
FALLS THROUGH MUCH OF THE PERIOD. GENERALLY SOUTH OF A GREAT FALLS
TO LEWISTOWN LINE...EXPECT ISOLATED/SCATTERED SHOWERS/THUNDERSTORMS.
THE THUNDERSTORMS WILL BE MORE NUMEROUS SOUTH OF I90. MOST STORMS
WILL DIMINISH BY 03Z SAT BUT SCATTERED SHOWERS WILL CONTINUE OVER
CENTRAL MT THRU SAT MORNING. MVFR CONDITIONS ARE POSSIBLE IN/NEAR
ANY THUNDERSTORMS. BRUSDA

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  47  64  43  65 /  20  40  20  20
CTB  42  67  38  67 /  10  20  10  10
HLN  48  64  45  67 /  40  70  40  20
BZN  42  61  41  62 /  30  60  40  40
WEY  34  57  33  57 /  60  60  40  30
DLN  44  62  41  63 /  30  50  30  30
HVR  42  70  41  71 /  20  20  10  20
LWT  45  61  42  61 /  40  50  20  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS




000
FXUS65 KTFX 222013
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
213 PM MDT FRI MAY 22 2015

.DISCUSSION...THIS AFTERNOON THROUGH MEMORIAL DAY AFTERNOON.
CURRENT RADAR/SATELLITE IMAGERY SHOWING SCATTERED SHOWERS AND A FEW
SMALL THUNDERSTORMS DEVELOPING MAINLY FROM THE LITTLE BELT AND SNOWY
MTNS SOUTH TO THE MT/ID BORDER.  EXPECT PRECIPITATION COVERAGE TO
INCREASE OVER THE SOUTHWEST COUNTIES AND EXTEND INTO PARTS OF
CASCADE/CHOUTEAU/FERGUS/JUDITH BASIN COUNTIES BY LATE AFTN AS
ADDITIONAL MOISTURE ARRIVES FROM IDAHO/WYOMING.  MOISTURE PUSH IS
DRIVEN BY A SLOW-MOVING UPPER-LEVEL LOW PRESSURE AREA PRESENTLY
CENTERED AT THE CA/NV/AZ BORDER.  FORECAST MODELS REMAIN IN VERY
GOOD AGREEMENT THAT THE LOW WILL TRACK GRADUALLY TO THE NORTHEAST
THROUGH THE GREAT BASIN OVER THE WEEKEND, REACHING EASTERN WYOMING
BY MIDDAY SUNDAY.  AS IT MOVES, EAST-SOUTHEAST WINDS ON THE
FRONTSIDE OF THE LOW`S CIRCULATION WILL BRING BOTH PACIFIC AND SOME
GULF OF MEXICO MOISTURE INTO MT, PRODUCING SCATTERED SHOWERS AND
THUNDERSTORMS EACH AFTERNOON AND EVENING THROUGH SUNDAY. NO STRONG
OR SEVERE STORMS ARE EXPECTED AT THIS TIME, AS INSTABILITY AND WIND
SHEAR PARAMETERS ARE FORECAST TO BE WEAK FOR THE NEXT COUPLE DAYS.
CONVECTIVE ACTIVITY WILL DISSIPATE OVER MOST OF THE FORECAST AREA
EACH EVENING NEAR/AFTER SUNSET.

LATEST MODELS ARE ALSO INDICATING A BETTER CHANCE OF SHORT-TERM DRY
CONDITIONS ON MONDAY AS OUR REGION WILL BE BETWEEN THE EXITING
WEEKEND WEATHER SYSTEM AND THE NEXT SHORTWAVE TROF MOVING INTO THE
PACIFIC NORTHWEST. ISOLATED SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE ALONG THE ROCKY MTN FRONT AND PARTS OF SOUTHWEST MT MON
AFTN/EVE AS THE TROF TAPS INTO RESIDUAL MOISTURE OVER WESTERN MT,
WHILE LOCATIONS GENERALLY ALONG/EAST OF THE INTERSTATE 15 CORRIDOR
REMAIN PRECIP FREE.
WARANAUSKAS


MONDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT
IN A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO
MIDWEEK. THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED
MONDAY NIGHT THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH
THEIR FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER
LOW NEAR VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS
IT MOVES INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER
LOW SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON
FRIDAY. DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR
PRECIPITATION FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM
TUESDAY ON OF SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS
THE CANADIAN BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED
THUNDERSTORMS DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO
NOT ANTICIPATE ANY SEVERE STORMS AT THIS TIME.
BLANK


&&

.AVIATION...
UPDATED 1125Z.
VFR CONDITIONS WILL CONTINUE TO PREVAIL FOR AREAS NORTH OF GREAT
FALLS THROUGH MUCH OF THE PERIOD. GENERALLY SOUTH OF A GREAT FALLS
TO LEWISTOWN LINE...EXPECT ISOLATED/SCATTERED SHOWERS/THUNDERSTORMS.
THE THUNDERSTORMS WILL BE MORE NUMEROUS SOUTH OF I90. MOST STORMS
WILL DIMINISH BY 03Z SAT BUT SCATTERED SHOWERS WILL CONTINUE OVER
CENTRAL MT THRU SAT MORNING. MVFR CONDITIONS ARE POSSIBLE IN/NEAR
ANY THUNDERSTORMS. BRUSDA

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  47  64  43  65 /  20  40  20  20
CTB  42  67  38  67 /  10  20  10  10
HLN  48  64  45  67 /  40  70  40  20
BZN  42  61  41  62 /  30  60  40  40
WEY  34  57  33  57 /  60  60  40  30
DLN  44  62  41  63 /  30  50  30  30
HVR  42  70  41  71 /  20  20  10  20
LWT  45  61  42  61 /  40  50  20  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 222013
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
213 PM MDT FRI MAY 22 2015

.DISCUSSION...THIS AFTERNOON THROUGH MEMORIAL DAY AFTERNOON.
CURRENT RADAR/SATELLITE IMAGERY SHOWING SCATTERED SHOWERS AND A FEW
SMALL THUNDERSTORMS DEVELOPING MAINLY FROM THE LITTLE BELT AND SNOWY
MTNS SOUTH TO THE MT/ID BORDER.  EXPECT PRECIPITATION COVERAGE TO
INCREASE OVER THE SOUTHWEST COUNTIES AND EXTEND INTO PARTS OF
CASCADE/CHOUTEAU/FERGUS/JUDITH BASIN COUNTIES BY LATE AFTN AS
ADDITIONAL MOISTURE ARRIVES FROM IDAHO/WYOMING.  MOISTURE PUSH IS
DRIVEN BY A SLOW-MOVING UPPER-LEVEL LOW PRESSURE AREA PRESENTLY
CENTERED AT THE CA/NV/AZ BORDER.  FORECAST MODELS REMAIN IN VERY
GOOD AGREEMENT THAT THE LOW WILL TRACK GRADUALLY TO THE NORTHEAST
THROUGH THE GREAT BASIN OVER THE WEEKEND, REACHING EASTERN WYOMING
BY MIDDAY SUNDAY.  AS IT MOVES, EAST-SOUTHEAST WINDS ON THE
FRONTSIDE OF THE LOW`S CIRCULATION WILL BRING BOTH PACIFIC AND SOME
GULF OF MEXICO MOISTURE INTO MT, PRODUCING SCATTERED SHOWERS AND
THUNDERSTORMS EACH AFTERNOON AND EVENING THROUGH SUNDAY. NO STRONG
OR SEVERE STORMS ARE EXPECTED AT THIS TIME, AS INSTABILITY AND WIND
SHEAR PARAMETERS ARE FORECAST TO BE WEAK FOR THE NEXT COUPLE DAYS.
CONVECTIVE ACTIVITY WILL DISSIPATE OVER MOST OF THE FORECAST AREA
EACH EVENING NEAR/AFTER SUNSET.

LATEST MODELS ARE ALSO INDICATING A BETTER CHANCE OF SHORT-TERM DRY
CONDITIONS ON MONDAY AS OUR REGION WILL BE BETWEEN THE EXITING
WEEKEND WEATHER SYSTEM AND THE NEXT SHORTWAVE TROF MOVING INTO THE
PACIFIC NORTHWEST. ISOLATED SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE ALONG THE ROCKY MTN FRONT AND PARTS OF SOUTHWEST MT MON
AFTN/EVE AS THE TROF TAPS INTO RESIDUAL MOISTURE OVER WESTERN MT,
WHILE LOCATIONS GENERALLY ALONG/EAST OF THE INTERSTATE 15 CORRIDOR
REMAIN PRECIP FREE.
WARANAUSKAS


MONDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT
IN A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO
MIDWEEK. THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED
MONDAY NIGHT THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH
THEIR FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER
LOW NEAR VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS
IT MOVES INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER
LOW SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON
FRIDAY. DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR
PRECIPITATION FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM
TUESDAY ON OF SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS
THE CANADIAN BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED
THUNDERSTORMS DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO
NOT ANTICIPATE ANY SEVERE STORMS AT THIS TIME.
BLANK


&&

.AVIATION...
UPDATED 1125Z.
VFR CONDITIONS WILL CONTINUE TO PREVAIL FOR AREAS NORTH OF GREAT
FALLS THROUGH MUCH OF THE PERIOD. GENERALLY SOUTH OF A GREAT FALLS
TO LEWISTOWN LINE...EXPECT ISOLATED/SCATTERED SHOWERS/THUNDERSTORMS.
THE THUNDERSTORMS WILL BE MORE NUMEROUS SOUTH OF I90. MOST STORMS
WILL DIMINISH BY 03Z SAT BUT SCATTERED SHOWERS WILL CONTINUE OVER
CENTRAL MT THRU SAT MORNING. MVFR CONDITIONS ARE POSSIBLE IN/NEAR
ANY THUNDERSTORMS. BRUSDA

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  47  64  43  65 /  20  40  20  20
CTB  42  67  38  67 /  10  20  10  10
HLN  48  64  45  67 /  40  70  40  20
BZN  42  61  41  62 /  30  60  40  40
WEY  34  57  33  57 /  60  60  40  30
DLN  44  62  41  63 /  30  50  30  30
HVR  42  70  41  71 /  20  20  10  20
LWT  45  61  42  61 /  40  50  20  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS




000
FXUS65 KGGW 221958
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
158 PM MDT FRI MAY 22 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SUNDAY...
...SCATTERED SHOWERS EXPECTED FOR THE HOLIDAY WEEKEND...

WATER VAPOR SHOWING A DEEP UPPER TROUGH THAT HAS DUG INTO THE BAJA
OF MEXICO TODAY. MOISTURE AT ALL LEVELS HAVE INCREASED OVER MONTANA
AS A RESULT AND THIS WILL ALSO INCREASE THE CHANCE FOR SHOWERS
OVER THE WEEKEND IN SOME AREAS.

MODELS DEPICTING A COMPLEX EVOLUTION OF SHOWERS THROUGH THIS PERIOD.
FIRST BATCH LOOKS TO FORM FROM INCREASING INSTABILITY OVER THE
CENTRAL AREAS OF MONTANA. SCATTERED AND ISOLATED TSTORMS MAY SPILL
INTO THE SW ZONES THIS EVENING.

THE NEXT BATCH OF PRECIPITATION MOVES NORTH OUT OF WYOMING TOWARD
THE SE ZONES. THE GFS BRINGS UP AN ASSOCIATED LOW CUTTING IT OFF AND
ALLOWING THE PRECIPITATION TO SOAK THE SE ZONES. THE NAM AND EC KEEP
THE WAVE OPEN AND THEREFORE PUSH MUCH OF THE MOISTURE TO OUR EAST.
BEING THAT IT HAS BEEN DRIER THAN NORMAL...HAVE SIDED WITH THE DRIER
SOLUTIONS.

EVEN IF THE RAINFALL MISSES THE AREA...COOLER TEMPERATURES CAN BE
EXPECTED OVER THE SE ZONES. TEMPERATURES ARE ONLY EXPECTED TO TOP
OUT IN THE LOWER 60S AFTER HIGHS NEAR 70 TODAY.

WINDS SATURDAY WILL BE LIGHTER THAN TODAY AND LOOK TO BE LESS THAN
LAKE WIND ADVISORY CRITERIA. TFJ


.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...

AFTERNOON UPDATE...
MOST OF THE LONG TERM STANDS WITH CHANGES BEING MINOR. SPLIT FLOW
IS MAINTAINED FROM SUNDAY NIGHT TO WEDNESDAY WITH WASHED OUT
SHORTWAVES.

A STRONG SIGNAL IS SHOWING UP FOR A TROUGH TO DROP INTO MONTANA
THURSDAY AFTERNOON AND BRING A FAIRLY SUBSTANTIAL COLD FRONT. HAVE
BIT ON THIS SIGNAL FROM BOTH THE EC AND GFS... BUT THERE MAY STILL
BE SOME ROOM TO DROP TEMPERATURES LOWER. COLD POOL WILL PROBABLY
KICK OUT BY THE WEEKEND AND JUST BEYOND THE NORMAL FORECAST RANGE.
GAH
PREVIOUS LONG TERM DISCUSSION...
MODELS HAVE THEIR DIFFERENCES WITH THE UPPER TROUGH/LOW LIFTING
NORTH INTO MONTANA AND THE DAKOTAS SUNDAY NIGHT AND MONDAY. ECMWF
MAINTAINS AN OPEN TROUGH AND KEEPS MOST OF THE MOISTURE TO THE
EAST WHILE THE GFS HAS A CLOSED LOW AND PUSHES MOISTURE FURTHER
WEST INTO EASTERN MONTANA. WILL SPLIT THE DIFFERENCE FOR NOW AND
MAINTAIN HIGHER POPS IN THE EAST.

THE REST OF THE PERIOD... MODELS TIME SYSTEMS DIFFERENTLY BUT EACH
ONE HAS FREQUENT SHORTWAVE TROUGHS GOING THROUGH MONTANA WHICH
WOULD LEAD TO SHOWERS AND THUNDERSTORMS AT TIMES THAT WOULD BE TOO
DIFFICULT TO TIME. WILL MAINTAIN CHANCE/SLIGHT CHANCE OF SHOWERS
AND THUNDERSTORMS THROUGH THE WEEK. FORRESTER

&&

.AVIATION...
FLIGHT CATEGORY: VFR.

SYNOPSIS: CLOUD COVER WILL INCREASE FROM THE SOUTH THIS AFTERNOON
INTO THE EVENING. AN UPPER LEVEL DISTURBANCE MOVES INTO THE AREA
OVERNIGHT AND SHOULD PROVIDE BELOW MENTION CHANCES FOR RAIN
SHOWERS AT KGDV AND KSDY TERMINALS LASTING THROUGH SUNDAY.

AREA WINDS: SOUTHEAST TO EAST AROUND 10 TO 20 KNOTS DURING THE
AFTERNOON... BECOMING EAST AROUND 10 KNOTS NEAR SUNDOWN...
INCREASING TO 10 TO 20 KTS AGAIN AFTER SUNUP.

GAH

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 8 PM MDT THIS EVENING FOR FORT PECK
LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN
VALLEY...GARFIELD...MCCONE...PETROLEUM.

&&

$$

WEATHER.GOV/GLASGOW





000
FXUS65 KGGW 221958
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
158 PM MDT FRI MAY 22 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SUNDAY...
...SCATTERED SHOWERS EXPECTED FOR THE HOLIDAY WEEKEND...

WATER VAPOR SHOWING A DEEP UPPER TROUGH THAT HAS DUG INTO THE BAJA
OF MEXICO TODAY. MOISTURE AT ALL LEVELS HAVE INCREASED OVER MONTANA
AS A RESULT AND THIS WILL ALSO INCREASE THE CHANCE FOR SHOWERS
OVER THE WEEKEND IN SOME AREAS.

MODELS DEPICTING A COMPLEX EVOLUTION OF SHOWERS THROUGH THIS PERIOD.
FIRST BATCH LOOKS TO FORM FROM INCREASING INSTABILITY OVER THE
CENTRAL AREAS OF MONTANA. SCATTERED AND ISOLATED TSTORMS MAY SPILL
INTO THE SW ZONES THIS EVENING.

THE NEXT BATCH OF PRECIPITATION MOVES NORTH OUT OF WYOMING TOWARD
THE SE ZONES. THE GFS BRINGS UP AN ASSOCIATED LOW CUTTING IT OFF AND
ALLOWING THE PRECIPITATION TO SOAK THE SE ZONES. THE NAM AND EC KEEP
THE WAVE OPEN AND THEREFORE PUSH MUCH OF THE MOISTURE TO OUR EAST.
BEING THAT IT HAS BEEN DRIER THAN NORMAL...HAVE SIDED WITH THE DRIER
SOLUTIONS.

EVEN IF THE RAINFALL MISSES THE AREA...COOLER TEMPERATURES CAN BE
EXPECTED OVER THE SE ZONES. TEMPERATURES ARE ONLY EXPECTED TO TOP
OUT IN THE LOWER 60S AFTER HIGHS NEAR 70 TODAY.

WINDS SATURDAY WILL BE LIGHTER THAN TODAY AND LOOK TO BE LESS THAN
LAKE WIND ADVISORY CRITERIA. TFJ


.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...

AFTERNOON UPDATE...
MOST OF THE LONG TERM STANDS WITH CHANGES BEING MINOR. SPLIT FLOW
IS MAINTAINED FROM SUNDAY NIGHT TO WEDNESDAY WITH WASHED OUT
SHORTWAVES.

A STRONG SIGNAL IS SHOWING UP FOR A TROUGH TO DROP INTO MONTANA
THURSDAY AFTERNOON AND BRING A FAIRLY SUBSTANTIAL COLD FRONT. HAVE
BIT ON THIS SIGNAL FROM BOTH THE EC AND GFS... BUT THERE MAY STILL
BE SOME ROOM TO DROP TEMPERATURES LOWER. COLD POOL WILL PROBABLY
KICK OUT BY THE WEEKEND AND JUST BEYOND THE NORMAL FORECAST RANGE.
GAH
PREVIOUS LONG TERM DISCUSSION...
MODELS HAVE THEIR DIFFERENCES WITH THE UPPER TROUGH/LOW LIFTING
NORTH INTO MONTANA AND THE DAKOTAS SUNDAY NIGHT AND MONDAY. ECMWF
MAINTAINS AN OPEN TROUGH AND KEEPS MOST OF THE MOISTURE TO THE
EAST WHILE THE GFS HAS A CLOSED LOW AND PUSHES MOISTURE FURTHER
WEST INTO EASTERN MONTANA. WILL SPLIT THE DIFFERENCE FOR NOW AND
MAINTAIN HIGHER POPS IN THE EAST.

THE REST OF THE PERIOD... MODELS TIME SYSTEMS DIFFERENTLY BUT EACH
ONE HAS FREQUENT SHORTWAVE TROUGHS GOING THROUGH MONTANA WHICH
WOULD LEAD TO SHOWERS AND THUNDERSTORMS AT TIMES THAT WOULD BE TOO
DIFFICULT TO TIME. WILL MAINTAIN CHANCE/SLIGHT CHANCE OF SHOWERS
AND THUNDERSTORMS THROUGH THE WEEK. FORRESTER

&&

.AVIATION...
FLIGHT CATEGORY: VFR.

SYNOPSIS: CLOUD COVER WILL INCREASE FROM THE SOUTH THIS AFTERNOON
INTO THE EVENING. AN UPPER LEVEL DISTURBANCE MOVES INTO THE AREA
OVERNIGHT AND SHOULD PROVIDE BELOW MENTION CHANCES FOR RAIN
SHOWERS AT KGDV AND KSDY TERMINALS LASTING THROUGH SUNDAY.

AREA WINDS: SOUTHEAST TO EAST AROUND 10 TO 20 KNOTS DURING THE
AFTERNOON... BECOMING EAST AROUND 10 KNOTS NEAR SUNDOWN...
INCREASING TO 10 TO 20 KTS AGAIN AFTER SUNUP.

GAH

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 8 PM MDT THIS EVENING FOR FORT PECK
LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN
VALLEY...GARFIELD...MCCONE...PETROLEUM.

&&

$$

WEATHER.GOV/GLASGOW





000
FXUS65 KGGW 221958
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
158 PM MDT FRI MAY 22 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SUNDAY...
...SCATTERED SHOWERS EXPECTED FOR THE HOLIDAY WEEKEND...

WATER VAPOR SHOWING A DEEP UPPER TROUGH THAT HAS DUG INTO THE BAJA
OF MEXICO TODAY. MOISTURE AT ALL LEVELS HAVE INCREASED OVER MONTANA
AS A RESULT AND THIS WILL ALSO INCREASE THE CHANCE FOR SHOWERS
OVER THE WEEKEND IN SOME AREAS.

MODELS DEPICTING A COMPLEX EVOLUTION OF SHOWERS THROUGH THIS PERIOD.
FIRST BATCH LOOKS TO FORM FROM INCREASING INSTABILITY OVER THE
CENTRAL AREAS OF MONTANA. SCATTERED AND ISOLATED TSTORMS MAY SPILL
INTO THE SW ZONES THIS EVENING.

THE NEXT BATCH OF PRECIPITATION MOVES NORTH OUT OF WYOMING TOWARD
THE SE ZONES. THE GFS BRINGS UP AN ASSOCIATED LOW CUTTING IT OFF AND
ALLOWING THE PRECIPITATION TO SOAK THE SE ZONES. THE NAM AND EC KEEP
THE WAVE OPEN AND THEREFORE PUSH MUCH OF THE MOISTURE TO OUR EAST.
BEING THAT IT HAS BEEN DRIER THAN NORMAL...HAVE SIDED WITH THE DRIER
SOLUTIONS.

EVEN IF THE RAINFALL MISSES THE AREA...COOLER TEMPERATURES CAN BE
EXPECTED OVER THE SE ZONES. TEMPERATURES ARE ONLY EXPECTED TO TOP
OUT IN THE LOWER 60S AFTER HIGHS NEAR 70 TODAY.

WINDS SATURDAY WILL BE LIGHTER THAN TODAY AND LOOK TO BE LESS THAN
LAKE WIND ADVISORY CRITERIA. TFJ


.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...

AFTERNOON UPDATE...
MOST OF THE LONG TERM STANDS WITH CHANGES BEING MINOR. SPLIT FLOW
IS MAINTAINED FROM SUNDAY NIGHT TO WEDNESDAY WITH WASHED OUT
SHORTWAVES.

A STRONG SIGNAL IS SHOWING UP FOR A TROUGH TO DROP INTO MONTANA
THURSDAY AFTERNOON AND BRING A FAIRLY SUBSTANTIAL COLD FRONT. HAVE
BIT ON THIS SIGNAL FROM BOTH THE EC AND GFS... BUT THERE MAY STILL
BE SOME ROOM TO DROP TEMPERATURES LOWER. COLD POOL WILL PROBABLY
KICK OUT BY THE WEEKEND AND JUST BEYOND THE NORMAL FORECAST RANGE.
GAH
PREVIOUS LONG TERM DISCUSSION...
MODELS HAVE THEIR DIFFERENCES WITH THE UPPER TROUGH/LOW LIFTING
NORTH INTO MONTANA AND THE DAKOTAS SUNDAY NIGHT AND MONDAY. ECMWF
MAINTAINS AN OPEN TROUGH AND KEEPS MOST OF THE MOISTURE TO THE
EAST WHILE THE GFS HAS A CLOSED LOW AND PUSHES MOISTURE FURTHER
WEST INTO EASTERN MONTANA. WILL SPLIT THE DIFFERENCE FOR NOW AND
MAINTAIN HIGHER POPS IN THE EAST.

THE REST OF THE PERIOD... MODELS TIME SYSTEMS DIFFERENTLY BUT EACH
ONE HAS FREQUENT SHORTWAVE TROUGHS GOING THROUGH MONTANA WHICH
WOULD LEAD TO SHOWERS AND THUNDERSTORMS AT TIMES THAT WOULD BE TOO
DIFFICULT TO TIME. WILL MAINTAIN CHANCE/SLIGHT CHANCE OF SHOWERS
AND THUNDERSTORMS THROUGH THE WEEK. FORRESTER

&&

.AVIATION...
FLIGHT CATEGORY: VFR.

SYNOPSIS: CLOUD COVER WILL INCREASE FROM THE SOUTH THIS AFTERNOON
INTO THE EVENING. AN UPPER LEVEL DISTURBANCE MOVES INTO THE AREA
OVERNIGHT AND SHOULD PROVIDE BELOW MENTION CHANCES FOR RAIN
SHOWERS AT KGDV AND KSDY TERMINALS LASTING THROUGH SUNDAY.

AREA WINDS: SOUTHEAST TO EAST AROUND 10 TO 20 KNOTS DURING THE
AFTERNOON... BECOMING EAST AROUND 10 KNOTS NEAR SUNDOWN...
INCREASING TO 10 TO 20 KTS AGAIN AFTER SUNUP.

GAH

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 8 PM MDT THIS EVENING FOR FORT PECK
LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN
VALLEY...GARFIELD...MCCONE...PETROLEUM.

&&

$$

WEATHER.GOV/GLASGOW





000
FXUS65 KGGW 221958
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
158 PM MDT FRI MAY 22 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SUNDAY...
...SCATTERED SHOWERS EXPECTED FOR THE HOLIDAY WEEKEND...

WATER VAPOR SHOWING A DEEP UPPER TROUGH THAT HAS DUG INTO THE BAJA
OF MEXICO TODAY. MOISTURE AT ALL LEVELS HAVE INCREASED OVER MONTANA
AS A RESULT AND THIS WILL ALSO INCREASE THE CHANCE FOR SHOWERS
OVER THE WEEKEND IN SOME AREAS.

MODELS DEPICTING A COMPLEX EVOLUTION OF SHOWERS THROUGH THIS PERIOD.
FIRST BATCH LOOKS TO FORM FROM INCREASING INSTABILITY OVER THE
CENTRAL AREAS OF MONTANA. SCATTERED AND ISOLATED TSTORMS MAY SPILL
INTO THE SW ZONES THIS EVENING.

THE NEXT BATCH OF PRECIPITATION MOVES NORTH OUT OF WYOMING TOWARD
THE SE ZONES. THE GFS BRINGS UP AN ASSOCIATED LOW CUTTING IT OFF AND
ALLOWING THE PRECIPITATION TO SOAK THE SE ZONES. THE NAM AND EC KEEP
THE WAVE OPEN AND THEREFORE PUSH MUCH OF THE MOISTURE TO OUR EAST.
BEING THAT IT HAS BEEN DRIER THAN NORMAL...HAVE SIDED WITH THE DRIER
SOLUTIONS.

EVEN IF THE RAINFALL MISSES THE AREA...COOLER TEMPERATURES CAN BE
EXPECTED OVER THE SE ZONES. TEMPERATURES ARE ONLY EXPECTED TO TOP
OUT IN THE LOWER 60S AFTER HIGHS NEAR 70 TODAY.

WINDS SATURDAY WILL BE LIGHTER THAN TODAY AND LOOK TO BE LESS THAN
LAKE WIND ADVISORY CRITERIA. TFJ


.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...

AFTERNOON UPDATE...
MOST OF THE LONG TERM STANDS WITH CHANGES BEING MINOR. SPLIT FLOW
IS MAINTAINED FROM SUNDAY NIGHT TO WEDNESDAY WITH WASHED OUT
SHORTWAVES.

A STRONG SIGNAL IS SHOWING UP FOR A TROUGH TO DROP INTO MONTANA
THURSDAY AFTERNOON AND BRING A FAIRLY SUBSTANTIAL COLD FRONT. HAVE
BIT ON THIS SIGNAL FROM BOTH THE EC AND GFS... BUT THERE MAY STILL
BE SOME ROOM TO DROP TEMPERATURES LOWER. COLD POOL WILL PROBABLY
KICK OUT BY THE WEEKEND AND JUST BEYOND THE NORMAL FORECAST RANGE.
GAH
PREVIOUS LONG TERM DISCUSSION...
MODELS HAVE THEIR DIFFERENCES WITH THE UPPER TROUGH/LOW LIFTING
NORTH INTO MONTANA AND THE DAKOTAS SUNDAY NIGHT AND MONDAY. ECMWF
MAINTAINS AN OPEN TROUGH AND KEEPS MOST OF THE MOISTURE TO THE
EAST WHILE THE GFS HAS A CLOSED LOW AND PUSHES MOISTURE FURTHER
WEST INTO EASTERN MONTANA. WILL SPLIT THE DIFFERENCE FOR NOW AND
MAINTAIN HIGHER POPS IN THE EAST.

THE REST OF THE PERIOD... MODELS TIME SYSTEMS DIFFERENTLY BUT EACH
ONE HAS FREQUENT SHORTWAVE TROUGHS GOING THROUGH MONTANA WHICH
WOULD LEAD TO SHOWERS AND THUNDERSTORMS AT TIMES THAT WOULD BE TOO
DIFFICULT TO TIME. WILL MAINTAIN CHANCE/SLIGHT CHANCE OF SHOWERS
AND THUNDERSTORMS THROUGH THE WEEK. FORRESTER

&&

.AVIATION...
FLIGHT CATEGORY: VFR.

SYNOPSIS: CLOUD COVER WILL INCREASE FROM THE SOUTH THIS AFTERNOON
INTO THE EVENING. AN UPPER LEVEL DISTURBANCE MOVES INTO THE AREA
OVERNIGHT AND SHOULD PROVIDE BELOW MENTION CHANCES FOR RAIN
SHOWERS AT KGDV AND KSDY TERMINALS LASTING THROUGH SUNDAY.

AREA WINDS: SOUTHEAST TO EAST AROUND 10 TO 20 KNOTS DURING THE
AFTERNOON... BECOMING EAST AROUND 10 KNOTS NEAR SUNDOWN...
INCREASING TO 10 TO 20 KTS AGAIN AFTER SUNUP.

GAH

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 8 PM MDT THIS EVENING FOR FORT PECK
LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN
VALLEY...GARFIELD...MCCONE...PETROLEUM.

&&

$$

WEATHER.GOV/GLASGOW





000
FXUS65 KTFX 221724
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1130 AM MDT FRI MAY 22 2015

AVIATION SECTION UPDATED

.UPDATE... NO FORECAST ADJUSTMENTS NEEDED FOR THE UPDATE. QUIET
CONDITIONS ACROSS THE REGION THIS MORNING WITH CLEAR TO PARTLY
CLOUDY SKIES COVERING MOST OF CENTRAL AND SOUTHWEST MT. SATELLITE
IMAGERY SHOWS NEXT MOISTURE PLUME GRADUALLY WORKING ITS WAY NORTH
FROM WYOMING.  THIS WILL BE THE SOURCE FOR ANOTHER ROUND OF
SCATTERED RAIN SHOWERS AND ISOLATED, SHORT-LIVED THUNDERSTORMS ALONG
AND SOUTHEAST OF A HAVRE-GREAT FALLS-HELENA LINE THIS AFTN/EARLY
EVE. WARANAUSKAS

&&


.AVIATION...
UPDATED 1125Z.
VFR CONDITIONS WILL CONTINUE TO PREVAIL FOR AREAS NORTH OF GREAT
FALLS THROUGH MUCH OF THE PERIOD. GENERALLY SOUTH OF A GREAT FALLS
TO LEWISTOWN LINE...EXPECT ISOLATED/SCATTERED SHOWERS/THUNDERSTORMS.
THE THUNDERSTORMS WILL BE MORE NUMEROUS SOUTH OF I90. MOST STORMS
WILL DIMINISH BY 03Z SAT BUT SCATTERED SHOWERS WILL CONTINUE OVER
CENTRAL MT THRU SAT MORNING. MVFR CONDITIONS ARE POSSIBLE IN/NEAR
ANY THUNDERSTORMS. BRUSDA

&&

.DISCUSSION...

TODAY THROUGH SUNDAY...A BROAD CYCLONIC CIRCULATION PRESENTLY MOVING
ASHORE OVER SOUTHERN CALIFORNIA IS FORECAST TO DRIFT SLOWLY
NORTHEAST ACROSS UTAH ON SATURDAY...AND EASTERN WYOMING ON SUNDAY.
THE SYSTEM IS NEARLY EQUIVALENT BAROTROPIC...PROVIDING WEAK SHEAR
BUT JUST ENOUGH INSTABILITY TO SUPPORT WIDESPREAD GENERAL
THUNDERSTORMS. SPECIFIC TO OUR CWA...AFTERNOON SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO REMAIN ACTIVE OVER THE SOUTHWEST
GIVEN DEEPER MOISTURE AND ELEVATED HEATING SOURCES OVER HIGHER
TERRAIN. SMALL HAIL AND GUSTY WINDS WILL AGAIN BE POSSIBLE IN A
FEW OF THESE SLOW MOVING THUNDERSTORMS...ESPECIALLY SATURDAY
AFTERNOON AS MID- LEVEL LAPSE RATES EXCEED 7 DEG/KM. DEEP-LAYER
EASTERLY FLOW CONTINUES OVER NORTH CENTRAL MONTANA. THIS IS
ASSOCIATED WITH DRIER AIR AND A MID-LEVEL INVERSION THAT WILL
SUPPRESS DEVELOPMENT OF SHOWERS IN THIS AREA. HOWEVER...ON
SATURDAY AFTERNOON A SUBTLE INVERTED SHORTWAVE TROUGH ROTATES
AROUND THE PARENT LOW TO HELP WEAKEN THE INVERSION AND ALLOW
SHOWERS AND THUNDERSTORMS TO SPREAD INTO SOUTHERN PORTIONS OF
NORTH CENTRAL MONTANA INCLUDING THE GREAT FALLS AREA. SHOWERS WILL
BE LESS WIDESPREAD ON SUNDAY AS THE PRIMARY TROUGH MOVES FURTHER
WAY INTO THE NORTHERN PLAINS. NUTTER

SUNDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT IN
A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO MIDWEEK.
THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED SUNDAY NIGHT AND
MEMORIAL DAY THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH THEIR
FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER LOW NEAR
VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS IT MOVES
INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER LOW
SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON FRIDAY.
DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR PRECIPITATION
FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM TUESDAY ON OF
SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS THE CANADIAN
BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED THUNDERSTORMS
DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO NOT ANTICIPATE
ANY SEVERE STORMS AT THIS TIME. BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  46  66  43 /  10  20  40  20
CTB  69  41  68  38 /   0  10  20  10
HLN  71  47  67  46 /  20  20  70  40
BZN  68  42  63  41 /  30  20  60  40
WEY  60  35  58  35 /  50  50  60  30
DLN  66  44  64  43 /  30  30  40  30
HVR  73  42  73  41 /  10  20  20  10
LWT  67  45  63  42 /  30  40  50  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 221724
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1130 AM MDT FRI MAY 22 2015

AVIATION SECTION UPDATED

.UPDATE... NO FORECAST ADJUSTMENTS NEEDED FOR THE UPDATE. QUIET
CONDITIONS ACROSS THE REGION THIS MORNING WITH CLEAR TO PARTLY
CLOUDY SKIES COVERING MOST OF CENTRAL AND SOUTHWEST MT. SATELLITE
IMAGERY SHOWS NEXT MOISTURE PLUME GRADUALLY WORKING ITS WAY NORTH
FROM WYOMING.  THIS WILL BE THE SOURCE FOR ANOTHER ROUND OF
SCATTERED RAIN SHOWERS AND ISOLATED, SHORT-LIVED THUNDERSTORMS ALONG
AND SOUTHEAST OF A HAVRE-GREAT FALLS-HELENA LINE THIS AFTN/EARLY
EVE. WARANAUSKAS

&&


.AVIATION...
UPDATED 1125Z.
VFR CONDITIONS WILL CONTINUE TO PREVAIL FOR AREAS NORTH OF GREAT
FALLS THROUGH MUCH OF THE PERIOD. GENERALLY SOUTH OF A GREAT FALLS
TO LEWISTOWN LINE...EXPECT ISOLATED/SCATTERED SHOWERS/THUNDERSTORMS.
THE THUNDERSTORMS WILL BE MORE NUMEROUS SOUTH OF I90. MOST STORMS
WILL DIMINISH BY 03Z SAT BUT SCATTERED SHOWERS WILL CONTINUE OVER
CENTRAL MT THRU SAT MORNING. MVFR CONDITIONS ARE POSSIBLE IN/NEAR
ANY THUNDERSTORMS. BRUSDA

&&

.DISCUSSION...

TODAY THROUGH SUNDAY...A BROAD CYCLONIC CIRCULATION PRESENTLY MOVING
ASHORE OVER SOUTHERN CALIFORNIA IS FORECAST TO DRIFT SLOWLY
NORTHEAST ACROSS UTAH ON SATURDAY...AND EASTERN WYOMING ON SUNDAY.
THE SYSTEM IS NEARLY EQUIVALENT BAROTROPIC...PROVIDING WEAK SHEAR
BUT JUST ENOUGH INSTABILITY TO SUPPORT WIDESPREAD GENERAL
THUNDERSTORMS. SPECIFIC TO OUR CWA...AFTERNOON SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO REMAIN ACTIVE OVER THE SOUTHWEST
GIVEN DEEPER MOISTURE AND ELEVATED HEATING SOURCES OVER HIGHER
TERRAIN. SMALL HAIL AND GUSTY WINDS WILL AGAIN BE POSSIBLE IN A
FEW OF THESE SLOW MOVING THUNDERSTORMS...ESPECIALLY SATURDAY
AFTERNOON AS MID- LEVEL LAPSE RATES EXCEED 7 DEG/KM. DEEP-LAYER
EASTERLY FLOW CONTINUES OVER NORTH CENTRAL MONTANA. THIS IS
ASSOCIATED WITH DRIER AIR AND A MID-LEVEL INVERSION THAT WILL
SUPPRESS DEVELOPMENT OF SHOWERS IN THIS AREA. HOWEVER...ON
SATURDAY AFTERNOON A SUBTLE INVERTED SHORTWAVE TROUGH ROTATES
AROUND THE PARENT LOW TO HELP WEAKEN THE INVERSION AND ALLOW
SHOWERS AND THUNDERSTORMS TO SPREAD INTO SOUTHERN PORTIONS OF
NORTH CENTRAL MONTANA INCLUDING THE GREAT FALLS AREA. SHOWERS WILL
BE LESS WIDESPREAD ON SUNDAY AS THE PRIMARY TROUGH MOVES FURTHER
WAY INTO THE NORTHERN PLAINS. NUTTER

SUNDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT IN
A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO MIDWEEK.
THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED SUNDAY NIGHT AND
MEMORIAL DAY THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH THEIR
FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER LOW NEAR
VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS IT MOVES
INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER LOW
SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON FRIDAY.
DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR PRECIPITATION
FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM TUESDAY ON OF
SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS THE CANADIAN
BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED THUNDERSTORMS
DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO NOT ANTICIPATE
ANY SEVERE STORMS AT THIS TIME. BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  46  66  43 /  10  20  40  20
CTB  69  41  68  38 /   0  10  20  10
HLN  71  47  67  46 /  20  20  70  40
BZN  68  42  63  41 /  30  20  60  40
WEY  60  35  58  35 /  50  50  60  30
DLN  66  44  64  43 /  30  30  40  30
HVR  73  42  73  41 /  10  20  20  10
LWT  67  45  63  42 /  30  40  50  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS




000
FXUS65 KTFX 221724
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1130 AM MDT FRI MAY 22 2015

AVIATION SECTION UPDATED

.UPDATE... NO FORECAST ADJUSTMENTS NEEDED FOR THE UPDATE. QUIET
CONDITIONS ACROSS THE REGION THIS MORNING WITH CLEAR TO PARTLY
CLOUDY SKIES COVERING MOST OF CENTRAL AND SOUTHWEST MT. SATELLITE
IMAGERY SHOWS NEXT MOISTURE PLUME GRADUALLY WORKING ITS WAY NORTH
FROM WYOMING.  THIS WILL BE THE SOURCE FOR ANOTHER ROUND OF
SCATTERED RAIN SHOWERS AND ISOLATED, SHORT-LIVED THUNDERSTORMS ALONG
AND SOUTHEAST OF A HAVRE-GREAT FALLS-HELENA LINE THIS AFTN/EARLY
EVE. WARANAUSKAS

&&


.AVIATION...
UPDATED 1125Z.
VFR CONDITIONS WILL CONTINUE TO PREVAIL FOR AREAS NORTH OF GREAT
FALLS THROUGH MUCH OF THE PERIOD. GENERALLY SOUTH OF A GREAT FALLS
TO LEWISTOWN LINE...EXPECT ISOLATED/SCATTERED SHOWERS/THUNDERSTORMS.
THE THUNDERSTORMS WILL BE MORE NUMEROUS SOUTH OF I90. MOST STORMS
WILL DIMINISH BY 03Z SAT BUT SCATTERED SHOWERS WILL CONTINUE OVER
CENTRAL MT THRU SAT MORNING. MVFR CONDITIONS ARE POSSIBLE IN/NEAR
ANY THUNDERSTORMS. BRUSDA

&&

.DISCUSSION...

TODAY THROUGH SUNDAY...A BROAD CYCLONIC CIRCULATION PRESENTLY MOVING
ASHORE OVER SOUTHERN CALIFORNIA IS FORECAST TO DRIFT SLOWLY
NORTHEAST ACROSS UTAH ON SATURDAY...AND EASTERN WYOMING ON SUNDAY.
THE SYSTEM IS NEARLY EQUIVALENT BAROTROPIC...PROVIDING WEAK SHEAR
BUT JUST ENOUGH INSTABILITY TO SUPPORT WIDESPREAD GENERAL
THUNDERSTORMS. SPECIFIC TO OUR CWA...AFTERNOON SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO REMAIN ACTIVE OVER THE SOUTHWEST
GIVEN DEEPER MOISTURE AND ELEVATED HEATING SOURCES OVER HIGHER
TERRAIN. SMALL HAIL AND GUSTY WINDS WILL AGAIN BE POSSIBLE IN A
FEW OF THESE SLOW MOVING THUNDERSTORMS...ESPECIALLY SATURDAY
AFTERNOON AS MID- LEVEL LAPSE RATES EXCEED 7 DEG/KM. DEEP-LAYER
EASTERLY FLOW CONTINUES OVER NORTH CENTRAL MONTANA. THIS IS
ASSOCIATED WITH DRIER AIR AND A MID-LEVEL INVERSION THAT WILL
SUPPRESS DEVELOPMENT OF SHOWERS IN THIS AREA. HOWEVER...ON
SATURDAY AFTERNOON A SUBTLE INVERTED SHORTWAVE TROUGH ROTATES
AROUND THE PARENT LOW TO HELP WEAKEN THE INVERSION AND ALLOW
SHOWERS AND THUNDERSTORMS TO SPREAD INTO SOUTHERN PORTIONS OF
NORTH CENTRAL MONTANA INCLUDING THE GREAT FALLS AREA. SHOWERS WILL
BE LESS WIDESPREAD ON SUNDAY AS THE PRIMARY TROUGH MOVES FURTHER
WAY INTO THE NORTHERN PLAINS. NUTTER

SUNDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT IN
A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO MIDWEEK.
THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED SUNDAY NIGHT AND
MEMORIAL DAY THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH THEIR
FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER LOW NEAR
VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS IT MOVES
INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER LOW
SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON FRIDAY.
DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR PRECIPITATION
FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM TUESDAY ON OF
SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS THE CANADIAN
BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED THUNDERSTORMS
DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO NOT ANTICIPATE
ANY SEVERE STORMS AT THIS TIME. BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  46  66  43 /  10  20  40  20
CTB  69  41  68  38 /   0  10  20  10
HLN  71  47  67  46 /  20  20  70  40
BZN  68  42  63  41 /  30  20  60  40
WEY  60  35  58  35 /  50  50  60  30
DLN  66  44  64  43 /  30  30  40  30
HVR  73  42  73  41 /  10  20  20  10
LWT  67  45  63  42 /  30  40  50  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS




000
FXUS65 KTFX 221540
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
935 AM MDT FRI MAY 22 2015

.UPDATE... NO FORECAST ADJUSTMENTS NEEDED FOR THE UPDATE. QUIET
CONDITIONS ACROSS THE REGION THIS MORNING WITH CLEAR TO PARTLY
CLOUDY SKIES COVERING MOST OF CENTRAL AND SOUTHWEST MT. SATELLITE
IMAGERY SHOWS NEXT MOISTURE PLUME GRADUALLY WORKING ITS WAY NORTH
FROM WYOMING.  THIS WILL BE THE SOURCE FOR ANOTHER ROUND OF
SCATTERED RAIN SHOWERS AND ISOLATED, SHORT-LIVED THUNDERSTORMS ALONG
AND SOUTHEAST OF A HAVRE-GREAT FALLS-HELENA LINE THIS AFTN/EARLY
EVE. WARANAUSKAS

&&

.DISCUSSION...

TODAY THROUGH SUNDAY...A BROAD CYCLONIC CIRCULATION PRESENTLY MOVING
ASHORE OVER SOUTHERN CALIFORNIA IS FORECAST TO DRIFT SLOWLY
NORTHEAST ACROSS UTAH ON SATURDAY...AND EASTERN WYOMING ON SUNDAY.
THE SYSTEM IS NEARLY EQUIVALENT BAROTROPIC...PROVIDING WEAK SHEAR
BUT JUST ENOUGH INSTABILITY TO SUPPORT WIDESPREAD GENERAL
THUNDERSTORMS. SPECIFIC TO OUR CWA...AFTERNOON SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO REMAIN ACTIVE OVER THE SOUTHWEST
GIVEN DEEPER MOISTURE AND ELEVATED HEATING SOURCES OVER HIGHER
TERRAIN. SMALL HAIL AND GUSTY WINDS WILL AGAIN BE POSSIBLE IN A
FEW OF THESE SLOW MOVING THUNDERSTORMS...ESPECIALLY SATURDAY
AFTERNOON AS MID- LEVEL LAPSE RATES EXCEED 7 DEG/KM. DEEP-LAYER
EASTERLY FLOW CONTINUES OVER NORTH CENTRAL MONTANA. THIS IS
ASSOCIATED WITH DRIER AIR AND A MID-LEVEL INVERSION THAT WILL
SUPPRESS DEVELOPMENT OF SHOWERS IN THIS AREA. HOWEVER...ON
SATURDAY AFTERNOON A SUBTLE INVERTED SHORTWAVE TROUGH ROTATES
AROUND THE PARENT LOW TO HELP WEAKEN THE INVERSION AND ALLOW
SHOWERS AND THUNDERSTORMS TO SPREAD INTO SOUTHERN PORTIONS OF
NORTH CENTRAL MONTANA INCLUDING THE GREAT FALLS AREA. SHOWERS WILL
BE LESS WIDESPREAD ON SUNDAY AS THE PRIMARY TROUGH MOVES FURTHER
WAY INTO THE NORTHERN PLAINS. NUTTER

SUNDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT IN
A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO MIDWEEK.
THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED SUNDAY NIGHT AND
MEMORIAL DAY THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH THEIR
FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER LOW NEAR
VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS IT MOVES
INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER LOW
SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON FRIDAY.
DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR PRECIPITATION
FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM TUESDAY ON OF
SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS THE CANADIAN
BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED THUNDERSTORMS
DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO NOT ANTICIPATE
ANY SEVERE STORMS AT THIS TIME. BLANK

&&

.AVIATION... UPDATED 1125Z.

EXPECT VFR CONDITIONS. THE EXCEPTION TO THIS IS THAT THERE COULD BE
PATCHY FOG IN THE VALLEYS OF SOUTHWEST MONTANA EARLY THIS MORNING.
ALTHOUGH MVFR/IFR VISIBILITIES IN FOG CAN NOT BE TOTALLY RULED OUT
AT KBZN AND KHLN..THINK THE THREAT OF FOG AT THOSE TWO SITES IS LOW
ENOUGH THAT IT WAS NOT INCLUDED IN THE RESPECTIVE TAF FORECASTS.
ISOLATED SHOWERS WILL DEVELOP OVER THE MOUNTAINS OF SOUTHWEST
MONTANA THIS MORNING AND POSSIBLY AS FAR NORTH AS THE LITTLE BELT
MOUNTAINS. SHOWERS WILL INCREASE IN COVERAGE THIS AFTERNOON AND
SCATTERED THUNDERSTORMS WILL DEVELOP. SHOWERS/THUNDERSTORMS WILL
MOVE SLOWLY AND MAINLY WESTWARD. THEY WILL ALSO BE MAINLY NEAR THE
MOUNTAINS. SHOWER AND THUNDERSTORMS ARE UNLIKELY NORTHWEST OF A LINE
FROM KGTF TO KHVR. SHOWERS AND THUNDERSTORMS WILL DIMINISH THIS
EVENING BUT COULD LINGER OVER CENTRAL MONTANA AFTER MIDNIGHT. BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  46  66  43 /  10  20  40  20
CTB  69  41  68  38 /   0  10  20  10
HLN  71  47  67  46 /  20  20  70  40
BZN  68  42  63  41 /  30  20  60  40
WEY  60  35  58  35 /  50  50  60  30
DLN  66  44  64  43 /  30  30  40  30
HVR  73  42  73  41 /  10  20  20  10
LWT  67  45  63  42 /  30  40  50  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 221540
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
935 AM MDT FRI MAY 22 2015

.UPDATE... NO FORECAST ADJUSTMENTS NEEDED FOR THE UPDATE. QUIET
CONDITIONS ACROSS THE REGION THIS MORNING WITH CLEAR TO PARTLY
CLOUDY SKIES COVERING MOST OF CENTRAL AND SOUTHWEST MT. SATELLITE
IMAGERY SHOWS NEXT MOISTURE PLUME GRADUALLY WORKING ITS WAY NORTH
FROM WYOMING.  THIS WILL BE THE SOURCE FOR ANOTHER ROUND OF
SCATTERED RAIN SHOWERS AND ISOLATED, SHORT-LIVED THUNDERSTORMS ALONG
AND SOUTHEAST OF A HAVRE-GREAT FALLS-HELENA LINE THIS AFTN/EARLY
EVE. WARANAUSKAS

&&

.DISCUSSION...

TODAY THROUGH SUNDAY...A BROAD CYCLONIC CIRCULATION PRESENTLY MOVING
ASHORE OVER SOUTHERN CALIFORNIA IS FORECAST TO DRIFT SLOWLY
NORTHEAST ACROSS UTAH ON SATURDAY...AND EASTERN WYOMING ON SUNDAY.
THE SYSTEM IS NEARLY EQUIVALENT BAROTROPIC...PROVIDING WEAK SHEAR
BUT JUST ENOUGH INSTABILITY TO SUPPORT WIDESPREAD GENERAL
THUNDERSTORMS. SPECIFIC TO OUR CWA...AFTERNOON SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO REMAIN ACTIVE OVER THE SOUTHWEST
GIVEN DEEPER MOISTURE AND ELEVATED HEATING SOURCES OVER HIGHER
TERRAIN. SMALL HAIL AND GUSTY WINDS WILL AGAIN BE POSSIBLE IN A
FEW OF THESE SLOW MOVING THUNDERSTORMS...ESPECIALLY SATURDAY
AFTERNOON AS MID- LEVEL LAPSE RATES EXCEED 7 DEG/KM. DEEP-LAYER
EASTERLY FLOW CONTINUES OVER NORTH CENTRAL MONTANA. THIS IS
ASSOCIATED WITH DRIER AIR AND A MID-LEVEL INVERSION THAT WILL
SUPPRESS DEVELOPMENT OF SHOWERS IN THIS AREA. HOWEVER...ON
SATURDAY AFTERNOON A SUBTLE INVERTED SHORTWAVE TROUGH ROTATES
AROUND THE PARENT LOW TO HELP WEAKEN THE INVERSION AND ALLOW
SHOWERS AND THUNDERSTORMS TO SPREAD INTO SOUTHERN PORTIONS OF
NORTH CENTRAL MONTANA INCLUDING THE GREAT FALLS AREA. SHOWERS WILL
BE LESS WIDESPREAD ON SUNDAY AS THE PRIMARY TROUGH MOVES FURTHER
WAY INTO THE NORTHERN PLAINS. NUTTER

SUNDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT IN
A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO MIDWEEK.
THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED SUNDAY NIGHT AND
MEMORIAL DAY THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH THEIR
FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER LOW NEAR
VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS IT MOVES
INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER LOW
SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON FRIDAY.
DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR PRECIPITATION
FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM TUESDAY ON OF
SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS THE CANADIAN
BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED THUNDERSTORMS
DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO NOT ANTICIPATE
ANY SEVERE STORMS AT THIS TIME. BLANK

&&

.AVIATION... UPDATED 1125Z.

EXPECT VFR CONDITIONS. THE EXCEPTION TO THIS IS THAT THERE COULD BE
PATCHY FOG IN THE VALLEYS OF SOUTHWEST MONTANA EARLY THIS MORNING.
ALTHOUGH MVFR/IFR VISIBILITIES IN FOG CAN NOT BE TOTALLY RULED OUT
AT KBZN AND KHLN..THINK THE THREAT OF FOG AT THOSE TWO SITES IS LOW
ENOUGH THAT IT WAS NOT INCLUDED IN THE RESPECTIVE TAF FORECASTS.
ISOLATED SHOWERS WILL DEVELOP OVER THE MOUNTAINS OF SOUTHWEST
MONTANA THIS MORNING AND POSSIBLY AS FAR NORTH AS THE LITTLE BELT
MOUNTAINS. SHOWERS WILL INCREASE IN COVERAGE THIS AFTERNOON AND
SCATTERED THUNDERSTORMS WILL DEVELOP. SHOWERS/THUNDERSTORMS WILL
MOVE SLOWLY AND MAINLY WESTWARD. THEY WILL ALSO BE MAINLY NEAR THE
MOUNTAINS. SHOWER AND THUNDERSTORMS ARE UNLIKELY NORTHWEST OF A LINE
FROM KGTF TO KHVR. SHOWERS AND THUNDERSTORMS WILL DIMINISH THIS
EVENING BUT COULD LINGER OVER CENTRAL MONTANA AFTER MIDNIGHT. BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  46  66  43 /  10  20  40  20
CTB  69  41  68  38 /   0  10  20  10
HLN  71  47  67  46 /  20  20  70  40
BZN  68  42  63  41 /  30  20  60  40
WEY  60  35  58  35 /  50  50  60  30
DLN  66  44  64  43 /  30  30  40  30
HVR  73  42  73  41 /  10  20  20  10
LWT  67  45  63  42 /  30  40  50  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS




000
FXUS65 KTFX 221540
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
935 AM MDT FRI MAY 22 2015

.UPDATE... NO FORECAST ADJUSTMENTS NEEDED FOR THE UPDATE. QUIET
CONDITIONS ACROSS THE REGION THIS MORNING WITH CLEAR TO PARTLY
CLOUDY SKIES COVERING MOST OF CENTRAL AND SOUTHWEST MT. SATELLITE
IMAGERY SHOWS NEXT MOISTURE PLUME GRADUALLY WORKING ITS WAY NORTH
FROM WYOMING.  THIS WILL BE THE SOURCE FOR ANOTHER ROUND OF
SCATTERED RAIN SHOWERS AND ISOLATED, SHORT-LIVED THUNDERSTORMS ALONG
AND SOUTHEAST OF A HAVRE-GREAT FALLS-HELENA LINE THIS AFTN/EARLY
EVE. WARANAUSKAS

&&

.DISCUSSION...

TODAY THROUGH SUNDAY...A BROAD CYCLONIC CIRCULATION PRESENTLY MOVING
ASHORE OVER SOUTHERN CALIFORNIA IS FORECAST TO DRIFT SLOWLY
NORTHEAST ACROSS UTAH ON SATURDAY...AND EASTERN WYOMING ON SUNDAY.
THE SYSTEM IS NEARLY EQUIVALENT BAROTROPIC...PROVIDING WEAK SHEAR
BUT JUST ENOUGH INSTABILITY TO SUPPORT WIDESPREAD GENERAL
THUNDERSTORMS. SPECIFIC TO OUR CWA...AFTERNOON SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO REMAIN ACTIVE OVER THE SOUTHWEST
GIVEN DEEPER MOISTURE AND ELEVATED HEATING SOURCES OVER HIGHER
TERRAIN. SMALL HAIL AND GUSTY WINDS WILL AGAIN BE POSSIBLE IN A
FEW OF THESE SLOW MOVING THUNDERSTORMS...ESPECIALLY SATURDAY
AFTERNOON AS MID- LEVEL LAPSE RATES EXCEED 7 DEG/KM. DEEP-LAYER
EASTERLY FLOW CONTINUES OVER NORTH CENTRAL MONTANA. THIS IS
ASSOCIATED WITH DRIER AIR AND A MID-LEVEL INVERSION THAT WILL
SUPPRESS DEVELOPMENT OF SHOWERS IN THIS AREA. HOWEVER...ON
SATURDAY AFTERNOON A SUBTLE INVERTED SHORTWAVE TROUGH ROTATES
AROUND THE PARENT LOW TO HELP WEAKEN THE INVERSION AND ALLOW
SHOWERS AND THUNDERSTORMS TO SPREAD INTO SOUTHERN PORTIONS OF
NORTH CENTRAL MONTANA INCLUDING THE GREAT FALLS AREA. SHOWERS WILL
BE LESS WIDESPREAD ON SUNDAY AS THE PRIMARY TROUGH MOVES FURTHER
WAY INTO THE NORTHERN PLAINS. NUTTER

SUNDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT IN
A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO MIDWEEK.
THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED SUNDAY NIGHT AND
MEMORIAL DAY THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH THEIR
FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER LOW NEAR
VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS IT MOVES
INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER LOW
SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON FRIDAY.
DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR PRECIPITATION
FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM TUESDAY ON OF
SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS THE CANADIAN
BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED THUNDERSTORMS
DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO NOT ANTICIPATE
ANY SEVERE STORMS AT THIS TIME. BLANK

&&

.AVIATION... UPDATED 1125Z.

EXPECT VFR CONDITIONS. THE EXCEPTION TO THIS IS THAT THERE COULD BE
PATCHY FOG IN THE VALLEYS OF SOUTHWEST MONTANA EARLY THIS MORNING.
ALTHOUGH MVFR/IFR VISIBILITIES IN FOG CAN NOT BE TOTALLY RULED OUT
AT KBZN AND KHLN..THINK THE THREAT OF FOG AT THOSE TWO SITES IS LOW
ENOUGH THAT IT WAS NOT INCLUDED IN THE RESPECTIVE TAF FORECASTS.
ISOLATED SHOWERS WILL DEVELOP OVER THE MOUNTAINS OF SOUTHWEST
MONTANA THIS MORNING AND POSSIBLY AS FAR NORTH AS THE LITTLE BELT
MOUNTAINS. SHOWERS WILL INCREASE IN COVERAGE THIS AFTERNOON AND
SCATTERED THUNDERSTORMS WILL DEVELOP. SHOWERS/THUNDERSTORMS WILL
MOVE SLOWLY AND MAINLY WESTWARD. THEY WILL ALSO BE MAINLY NEAR THE
MOUNTAINS. SHOWER AND THUNDERSTORMS ARE UNLIKELY NORTHWEST OF A LINE
FROM KGTF TO KHVR. SHOWERS AND THUNDERSTORMS WILL DIMINISH THIS
EVENING BUT COULD LINGER OVER CENTRAL MONTANA AFTER MIDNIGHT. BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  46  66  43 /  10  20  40  20
CTB  69  41  68  38 /   0  10  20  10
HLN  71  47  67  46 /  20  20  70  40
BZN  68  42  63  41 /  30  20  60  40
WEY  60  35  58  35 /  50  50  60  30
DLN  66  44  64  43 /  30  30  40  30
HVR  73  42  73  41 /  10  20  20  10
LWT  67  45  63  42 /  30  40  50  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS




000
FXUS65 KTFX 221540
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
935 AM MDT FRI MAY 22 2015

.UPDATE... NO FORECAST ADJUSTMENTS NEEDED FOR THE UPDATE. QUIET
CONDITIONS ACROSS THE REGION THIS MORNING WITH CLEAR TO PARTLY
CLOUDY SKIES COVERING MOST OF CENTRAL AND SOUTHWEST MT. SATELLITE
IMAGERY SHOWS NEXT MOISTURE PLUME GRADUALLY WORKING ITS WAY NORTH
FROM WYOMING.  THIS WILL BE THE SOURCE FOR ANOTHER ROUND OF
SCATTERED RAIN SHOWERS AND ISOLATED, SHORT-LIVED THUNDERSTORMS ALONG
AND SOUTHEAST OF A HAVRE-GREAT FALLS-HELENA LINE THIS AFTN/EARLY
EVE. WARANAUSKAS

&&

.DISCUSSION...

TODAY THROUGH SUNDAY...A BROAD CYCLONIC CIRCULATION PRESENTLY MOVING
ASHORE OVER SOUTHERN CALIFORNIA IS FORECAST TO DRIFT SLOWLY
NORTHEAST ACROSS UTAH ON SATURDAY...AND EASTERN WYOMING ON SUNDAY.
THE SYSTEM IS NEARLY EQUIVALENT BAROTROPIC...PROVIDING WEAK SHEAR
BUT JUST ENOUGH INSTABILITY TO SUPPORT WIDESPREAD GENERAL
THUNDERSTORMS. SPECIFIC TO OUR CWA...AFTERNOON SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO REMAIN ACTIVE OVER THE SOUTHWEST
GIVEN DEEPER MOISTURE AND ELEVATED HEATING SOURCES OVER HIGHER
TERRAIN. SMALL HAIL AND GUSTY WINDS WILL AGAIN BE POSSIBLE IN A
FEW OF THESE SLOW MOVING THUNDERSTORMS...ESPECIALLY SATURDAY
AFTERNOON AS MID- LEVEL LAPSE RATES EXCEED 7 DEG/KM. DEEP-LAYER
EASTERLY FLOW CONTINUES OVER NORTH CENTRAL MONTANA. THIS IS
ASSOCIATED WITH DRIER AIR AND A MID-LEVEL INVERSION THAT WILL
SUPPRESS DEVELOPMENT OF SHOWERS IN THIS AREA. HOWEVER...ON
SATURDAY AFTERNOON A SUBTLE INVERTED SHORTWAVE TROUGH ROTATES
AROUND THE PARENT LOW TO HELP WEAKEN THE INVERSION AND ALLOW
SHOWERS AND THUNDERSTORMS TO SPREAD INTO SOUTHERN PORTIONS OF
NORTH CENTRAL MONTANA INCLUDING THE GREAT FALLS AREA. SHOWERS WILL
BE LESS WIDESPREAD ON SUNDAY AS THE PRIMARY TROUGH MOVES FURTHER
WAY INTO THE NORTHERN PLAINS. NUTTER

SUNDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT IN
A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO MIDWEEK.
THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED SUNDAY NIGHT AND
MEMORIAL DAY THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH THEIR
FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER LOW NEAR
VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS IT MOVES
INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER LOW
SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON FRIDAY.
DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR PRECIPITATION
FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM TUESDAY ON OF
SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS THE CANADIAN
BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED THUNDERSTORMS
DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO NOT ANTICIPATE
ANY SEVERE STORMS AT THIS TIME. BLANK

&&

.AVIATION... UPDATED 1125Z.

EXPECT VFR CONDITIONS. THE EXCEPTION TO THIS IS THAT THERE COULD BE
PATCHY FOG IN THE VALLEYS OF SOUTHWEST MONTANA EARLY THIS MORNING.
ALTHOUGH MVFR/IFR VISIBILITIES IN FOG CAN NOT BE TOTALLY RULED OUT
AT KBZN AND KHLN..THINK THE THREAT OF FOG AT THOSE TWO SITES IS LOW
ENOUGH THAT IT WAS NOT INCLUDED IN THE RESPECTIVE TAF FORECASTS.
ISOLATED SHOWERS WILL DEVELOP OVER THE MOUNTAINS OF SOUTHWEST
MONTANA THIS MORNING AND POSSIBLY AS FAR NORTH AS THE LITTLE BELT
MOUNTAINS. SHOWERS WILL INCREASE IN COVERAGE THIS AFTERNOON AND
SCATTERED THUNDERSTORMS WILL DEVELOP. SHOWERS/THUNDERSTORMS WILL
MOVE SLOWLY AND MAINLY WESTWARD. THEY WILL ALSO BE MAINLY NEAR THE
MOUNTAINS. SHOWER AND THUNDERSTORMS ARE UNLIKELY NORTHWEST OF A LINE
FROM KGTF TO KHVR. SHOWERS AND THUNDERSTORMS WILL DIMINISH THIS
EVENING BUT COULD LINGER OVER CENTRAL MONTANA AFTER MIDNIGHT. BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  46  66  43 /  10  20  40  20
CTB  69  41  68  38 /   0  10  20  10
HLN  71  47  67  46 /  20  20  70  40
BZN  68  42  63  41 /  30  20  60  40
WEY  60  35  58  35 /  50  50  60  30
DLN  66  44  64  43 /  30  30  40  30
HVR  73  42  73  41 /  10  20  20  10
LWT  67  45  63  42 /  30  40  50  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS




000
FXUS65 KTFX 221540
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
935 AM MDT FRI MAY 22 2015

.UPDATE... NO FORECAST ADJUSTMENTS NEEDED FOR THE UPDATE. QUIET
CONDITIONS ACROSS THE REGION THIS MORNING WITH CLEAR TO PARTLY
CLOUDY SKIES COVERING MOST OF CENTRAL AND SOUTHWEST MT. SATELLITE
IMAGERY SHOWS NEXT MOISTURE PLUME GRADUALLY WORKING ITS WAY NORTH
FROM WYOMING.  THIS WILL BE THE SOURCE FOR ANOTHER ROUND OF
SCATTERED RAIN SHOWERS AND ISOLATED, SHORT-LIVED THUNDERSTORMS ALONG
AND SOUTHEAST OF A HAVRE-GREAT FALLS-HELENA LINE THIS AFTN/EARLY
EVE. WARANAUSKAS

&&

.DISCUSSION...

TODAY THROUGH SUNDAY...A BROAD CYCLONIC CIRCULATION PRESENTLY MOVING
ASHORE OVER SOUTHERN CALIFORNIA IS FORECAST TO DRIFT SLOWLY
NORTHEAST ACROSS UTAH ON SATURDAY...AND EASTERN WYOMING ON SUNDAY.
THE SYSTEM IS NEARLY EQUIVALENT BAROTROPIC...PROVIDING WEAK SHEAR
BUT JUST ENOUGH INSTABILITY TO SUPPORT WIDESPREAD GENERAL
THUNDERSTORMS. SPECIFIC TO OUR CWA...AFTERNOON SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO REMAIN ACTIVE OVER THE SOUTHWEST
GIVEN DEEPER MOISTURE AND ELEVATED HEATING SOURCES OVER HIGHER
TERRAIN. SMALL HAIL AND GUSTY WINDS WILL AGAIN BE POSSIBLE IN A
FEW OF THESE SLOW MOVING THUNDERSTORMS...ESPECIALLY SATURDAY
AFTERNOON AS MID- LEVEL LAPSE RATES EXCEED 7 DEG/KM. DEEP-LAYER
EASTERLY FLOW CONTINUES OVER NORTH CENTRAL MONTANA. THIS IS
ASSOCIATED WITH DRIER AIR AND A MID-LEVEL INVERSION THAT WILL
SUPPRESS DEVELOPMENT OF SHOWERS IN THIS AREA. HOWEVER...ON
SATURDAY AFTERNOON A SUBTLE INVERTED SHORTWAVE TROUGH ROTATES
AROUND THE PARENT LOW TO HELP WEAKEN THE INVERSION AND ALLOW
SHOWERS AND THUNDERSTORMS TO SPREAD INTO SOUTHERN PORTIONS OF
NORTH CENTRAL MONTANA INCLUDING THE GREAT FALLS AREA. SHOWERS WILL
BE LESS WIDESPREAD ON SUNDAY AS THE PRIMARY TROUGH MOVES FURTHER
WAY INTO THE NORTHERN PLAINS. NUTTER

SUNDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT IN
A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO MIDWEEK.
THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED SUNDAY NIGHT AND
MEMORIAL DAY THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH THEIR
FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER LOW NEAR
VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS IT MOVES
INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER LOW
SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON FRIDAY.
DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR PRECIPITATION
FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM TUESDAY ON OF
SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS THE CANADIAN
BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED THUNDERSTORMS
DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO NOT ANTICIPATE
ANY SEVERE STORMS AT THIS TIME. BLANK

&&

.AVIATION... UPDATED 1125Z.

EXPECT VFR CONDITIONS. THE EXCEPTION TO THIS IS THAT THERE COULD BE
PATCHY FOG IN THE VALLEYS OF SOUTHWEST MONTANA EARLY THIS MORNING.
ALTHOUGH MVFR/IFR VISIBILITIES IN FOG CAN NOT BE TOTALLY RULED OUT
AT KBZN AND KHLN..THINK THE THREAT OF FOG AT THOSE TWO SITES IS LOW
ENOUGH THAT IT WAS NOT INCLUDED IN THE RESPECTIVE TAF FORECASTS.
ISOLATED SHOWERS WILL DEVELOP OVER THE MOUNTAINS OF SOUTHWEST
MONTANA THIS MORNING AND POSSIBLY AS FAR NORTH AS THE LITTLE BELT
MOUNTAINS. SHOWERS WILL INCREASE IN COVERAGE THIS AFTERNOON AND
SCATTERED THUNDERSTORMS WILL DEVELOP. SHOWERS/THUNDERSTORMS WILL
MOVE SLOWLY AND MAINLY WESTWARD. THEY WILL ALSO BE MAINLY NEAR THE
MOUNTAINS. SHOWER AND THUNDERSTORMS ARE UNLIKELY NORTHWEST OF A LINE
FROM KGTF TO KHVR. SHOWERS AND THUNDERSTORMS WILL DIMINISH THIS
EVENING BUT COULD LINGER OVER CENTRAL MONTANA AFTER MIDNIGHT. BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  46  66  43 /  10  20  40  20
CTB  69  41  68  38 /   0  10  20  10
HLN  71  47  67  46 /  20  20  70  40
BZN  68  42  63  41 /  30  20  60  40
WEY  60  35  58  35 /  50  50  60  30
DLN  66  44  64  43 /  30  30  40  30
HVR  73  42  73  41 /  10  20  20  10
LWT  67  45  63  42 /  30  40  50  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS




000
FXUS65 KTFX 221540
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
935 AM MDT FRI MAY 22 2015

.UPDATE... NO FORECAST ADJUSTMENTS NEEDED FOR THE UPDATE. QUIET
CONDITIONS ACROSS THE REGION THIS MORNING WITH CLEAR TO PARTLY
CLOUDY SKIES COVERING MOST OF CENTRAL AND SOUTHWEST MT. SATELLITE
IMAGERY SHOWS NEXT MOISTURE PLUME GRADUALLY WORKING ITS WAY NORTH
FROM WYOMING.  THIS WILL BE THE SOURCE FOR ANOTHER ROUND OF
SCATTERED RAIN SHOWERS AND ISOLATED, SHORT-LIVED THUNDERSTORMS ALONG
AND SOUTHEAST OF A HAVRE-GREAT FALLS-HELENA LINE THIS AFTN/EARLY
EVE. WARANAUSKAS

&&

.DISCUSSION...

TODAY THROUGH SUNDAY...A BROAD CYCLONIC CIRCULATION PRESENTLY MOVING
ASHORE OVER SOUTHERN CALIFORNIA IS FORECAST TO DRIFT SLOWLY
NORTHEAST ACROSS UTAH ON SATURDAY...AND EASTERN WYOMING ON SUNDAY.
THE SYSTEM IS NEARLY EQUIVALENT BAROTROPIC...PROVIDING WEAK SHEAR
BUT JUST ENOUGH INSTABILITY TO SUPPORT WIDESPREAD GENERAL
THUNDERSTORMS. SPECIFIC TO OUR CWA...AFTERNOON SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO REMAIN ACTIVE OVER THE SOUTHWEST
GIVEN DEEPER MOISTURE AND ELEVATED HEATING SOURCES OVER HIGHER
TERRAIN. SMALL HAIL AND GUSTY WINDS WILL AGAIN BE POSSIBLE IN A
FEW OF THESE SLOW MOVING THUNDERSTORMS...ESPECIALLY SATURDAY
AFTERNOON AS MID- LEVEL LAPSE RATES EXCEED 7 DEG/KM. DEEP-LAYER
EASTERLY FLOW CONTINUES OVER NORTH CENTRAL MONTANA. THIS IS
ASSOCIATED WITH DRIER AIR AND A MID-LEVEL INVERSION THAT WILL
SUPPRESS DEVELOPMENT OF SHOWERS IN THIS AREA. HOWEVER...ON
SATURDAY AFTERNOON A SUBTLE INVERTED SHORTWAVE TROUGH ROTATES
AROUND THE PARENT LOW TO HELP WEAKEN THE INVERSION AND ALLOW
SHOWERS AND THUNDERSTORMS TO SPREAD INTO SOUTHERN PORTIONS OF
NORTH CENTRAL MONTANA INCLUDING THE GREAT FALLS AREA. SHOWERS WILL
BE LESS WIDESPREAD ON SUNDAY AS THE PRIMARY TROUGH MOVES FURTHER
WAY INTO THE NORTHERN PLAINS. NUTTER

SUNDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT IN
A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO MIDWEEK.
THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED SUNDAY NIGHT AND
MEMORIAL DAY THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH THEIR
FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER LOW NEAR
VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS IT MOVES
INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER LOW
SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON FRIDAY.
DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR PRECIPITATION
FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM TUESDAY ON OF
SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS THE CANADIAN
BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED THUNDERSTORMS
DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO NOT ANTICIPATE
ANY SEVERE STORMS AT THIS TIME. BLANK

&&

.AVIATION... UPDATED 1125Z.

EXPECT VFR CONDITIONS. THE EXCEPTION TO THIS IS THAT THERE COULD BE
PATCHY FOG IN THE VALLEYS OF SOUTHWEST MONTANA EARLY THIS MORNING.
ALTHOUGH MVFR/IFR VISIBILITIES IN FOG CAN NOT BE TOTALLY RULED OUT
AT KBZN AND KHLN..THINK THE THREAT OF FOG AT THOSE TWO SITES IS LOW
ENOUGH THAT IT WAS NOT INCLUDED IN THE RESPECTIVE TAF FORECASTS.
ISOLATED SHOWERS WILL DEVELOP OVER THE MOUNTAINS OF SOUTHWEST
MONTANA THIS MORNING AND POSSIBLY AS FAR NORTH AS THE LITTLE BELT
MOUNTAINS. SHOWERS WILL INCREASE IN COVERAGE THIS AFTERNOON AND
SCATTERED THUNDERSTORMS WILL DEVELOP. SHOWERS/THUNDERSTORMS WILL
MOVE SLOWLY AND MAINLY WESTWARD. THEY WILL ALSO BE MAINLY NEAR THE
MOUNTAINS. SHOWER AND THUNDERSTORMS ARE UNLIKELY NORTHWEST OF A LINE
FROM KGTF TO KHVR. SHOWERS AND THUNDERSTORMS WILL DIMINISH THIS
EVENING BUT COULD LINGER OVER CENTRAL MONTANA AFTER MIDNIGHT. BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  46  66  43 /  10  20  40  20
CTB  69  41  68  38 /   0  10  20  10
HLN  71  47  67  46 /  20  20  70  40
BZN  68  42  63  41 /  30  20  60  40
WEY  60  35  58  35 /  50  50  60  30
DLN  66  44  64  43 /  30  30  40  30
HVR  73  42  73  41 /  10  20  20  10
LWT  67  45  63  42 /  30  40  50  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS




000
FXUS65 KBYZ 221525
AFDBYZ

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
925 AM MDT FRI MAY 22 2015

.UPDATE...

CURRENT FORECAST LOOKS TO BE IN GOOD SHAPE SO WILL NOT BE MAKING
ANY UPDATES THIS MORNING. AN UPPER LOW MOVING NORTH OUT OF EASTERN
COLORADO ALONG WITH A SECOND LOW APPROACHING THE FOUR CORNERS AREA
WILL BRING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS NORTHWARD
ACROSS OUR FORECAST AREA. THE BEST LOCATIONS FOR THE ACTIVITY
TODAY WILL BE OVER THE MOUNTAINS AND ADJACENT FOOTHILLS. HOOLEY

&&

.SHORT TERM...VALID FOR TDY AND SAT...

A DEEP UPPER LOW WAS PUSHING INTO SOUTHERN CALIFORNIA THIS HOUR.
THIS SYSTEM WILL BE RESPONSIBLE FOR OUR RELATIVELY UNSETTLED
FORECAST THROUGH THE WEEKEND. THE UPPER LOW WILL PUSH INTO
SOUTHERN NEVADA EARLY THIS AFTERNOON. A PIECE OF ENERGY OUT AHEAD
OF THE UPPER LOW...OVER NORTHEAST NEW MEXICO...WILL MOVE INTO EAST
CENTRAL WYOMING THIS AFTERNOON. THIS ENERGY WILL SPREAD CLOUDS AND
SHOWERS INTO THE FORECAST AREA. THE HIGHEST POPS WILL BE NEAREST
THE MOUNTAINS WITH UPSLOPE FLOW. ENOUGH INSTABILITY FOR ISOLATED
THUNDERSTORMS...MAINLY WEST. WEAK MID LEVEL FLOW WILL PRODUCE
PULSING ACTIVITY AND SO CELL WILL HAVE A HARD TIME MOVING OFF THE
FOOTHILLS.

THE UPPER LOW MOVES INTO COLORADO ON SATURDAY AND PUSHES THE
EASTERN ENERGY INTO SOUTHEAST MONTANA. THE GFS WAS STRONGER AND
FARTHER EAST WITH THIS ENERGY AND THUS HAS MORE QPF OVER SOUTHEAST
MONTANA. DID RAISE POPS OVER THE SOUTHEAST AS EVEN THE FARTHER
EAST ECMWF BROUGHT FORCING IN. UPSLOPE FLOW WILL KEEP SCATTERED
SHOWERS GOING OVER WESTERN AND CENTRAL ZONES WITH THE HIGHEST POPS
OVER THE WEST. ENOUGH INSTABILITY FOR THUNDER BUT SHOULD BE
LIMITED. MORE CLOUDS AND NORTHEAST WINDS AT 850MB WILL PROVIDE A
COOLER DAY ON SATURDAY. HIGHS TODAY SHOULD BE AROUND 70...WITH 60S
ON SATURDAY. TWH

.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...

SUNDAY...A LOW OVER THE DAKOTAS WILL CONTINUE TO PUSH EAST. THIS
WILL CONTINUE SLIGHT RAIN CHANCES ACROSS THE AREA...WITH BETTER
CHANCES FROM MILES CITY AND BROADUS EAST...AS PRECIP WRAPS AROUND
THE BACKSIDE OF THE LOW. THE GFS IS MUCH MORE AGGRESSIVE WITH
GENERATING QPF THAN THE ECMWF. GIVEN HOW THE GFS SEEMS TO HAS BEEN
OVERLY AGGRESSIVE WITH SEVERAL PAST SYSTEMS...NOT OVERLY CONFIDENT
WITH ITS AMOUNTS.

AFTER SOME BRIEF...WEAK RIDGING MONDAY INTO TUESDAY...ANOTHER LOW
SETS UP OVER THE PACIFIC NORTHWEST. THE GFS IS MUCH SLOWER AT
PROGRESSING THIS SYSTEM THAN THE EC. WITH EITHER SOLUTION...THE
AREA LOOKS TO SEE UNSETTLE SOUTHWEST FLOW ALOFT ALONG WITH EASTERLY
SURFACE FLOW. THIS WILL SEE PWAT VALUES INCREASING ACROSS THE
AREA. THOUGH THE REMAINDER OF THE EXTEND THERE WILL BE SLIGHT
CHANCES FOR RAIN ACROSS THE AREA...WITH THE HIGHEST CHANCES OVER
THE MOUNTAINS. GIVEN THE HIGHER PWATS...HEAVY RAIN IS A
POSSIBILITY. SOME INSTABILITY EXISTS DURING THE AFTERNOONS...SO
CANNOT RULE OUT AN ISOLATED THUNDERSTORM.

TEMPERATURES WILL GENERALLY BE NEAR SEASONAL NORMALS THROUGH THE
EXTENDED ALTHOUGH SUNDAY WILL BE COOLER AS THE LOW DEPARTS THE
AREA. REIMER


&&

.AVIATION...

EXPECT VFR CONDITIONS OVER THE NEXT 24 HOURS. SOME AFTERNOON
THUNDERSTORMS ARE POSSIBLE MOSTLY OVER THE MOUNTAINS...AND WILL
LIKELY DISSIPATE AFTER MOVING OFF THE HIGHER TERRAIN. SOME BRIEF
MVFR TO IFR CONDITIONS ALONG WITH GUSTY WINDS ARE POSSIBLE WITH
THESE THUNDERSTORMS. REIMER
&&

.PRELIMINARY POINT TEMP/POPS...

    TDY SAT     SUN     MON     TUE     WED     THU
-------------------------------------------------------
BIL 072 046/064 046/060 045/070 047/072 048/071 049/071
    3/T 23/T    23/T    32/T    23/T    33/T    33/T
LVM 067 044/062 042/061 040/067 043/068 043/066 044/069
    4/T 35/T    33/T    33/T    34/T    44/T    43/T
HDN 073 045/065 046/061 045/071 046/074 048/074 048/074
    3/T 23/T    33/T    32/T    23/T    33/T    33/T
MLS 073 046/064 046/062 047/067 046/073 049/072 049/071
    1/N 13/T    45/T    43/T    32/T    33/T    33/T
4BQ 069 043/059 046/058 046/065 045/072 048/071 048/070
    2/T 25/T    56/T    53/T    33/T    33/T    34/T
BHK 069 042/060 044/061 046/065 043/069 046/070 047/069
    1/N 15/T    47/T    65/T    43/T    33/T    33/T
SHR 065 041/059 043/056 041/065 042/070 045/070 045/069
    3/T 25/T    55/T    33/T    34/T    43/T    33/T

&&

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

&&

$$
WEATHER.GOV/BILLINGS



000
FXUS65 KBYZ 221525
AFDBYZ

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
925 AM MDT FRI MAY 22 2015

.UPDATE...

CURRENT FORECAST LOOKS TO BE IN GOOD SHAPE SO WILL NOT BE MAKING
ANY UPDATES THIS MORNING. AN UPPER LOW MOVING NORTH OUT OF EASTERN
COLORADO ALONG WITH A SECOND LOW APPROACHING THE FOUR CORNERS AREA
WILL BRING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS NORTHWARD
ACROSS OUR FORECAST AREA. THE BEST LOCATIONS FOR THE ACTIVITY
TODAY WILL BE OVER THE MOUNTAINS AND ADJACENT FOOTHILLS. HOOLEY

&&

.SHORT TERM...VALID FOR TDY AND SAT...

A DEEP UPPER LOW WAS PUSHING INTO SOUTHERN CALIFORNIA THIS HOUR.
THIS SYSTEM WILL BE RESPONSIBLE FOR OUR RELATIVELY UNSETTLED
FORECAST THROUGH THE WEEKEND. THE UPPER LOW WILL PUSH INTO
SOUTHERN NEVADA EARLY THIS AFTERNOON. A PIECE OF ENERGY OUT AHEAD
OF THE UPPER LOW...OVER NORTHEAST NEW MEXICO...WILL MOVE INTO EAST
CENTRAL WYOMING THIS AFTERNOON. THIS ENERGY WILL SPREAD CLOUDS AND
SHOWERS INTO THE FORECAST AREA. THE HIGHEST POPS WILL BE NEAREST
THE MOUNTAINS WITH UPSLOPE FLOW. ENOUGH INSTABILITY FOR ISOLATED
THUNDERSTORMS...MAINLY WEST. WEAK MID LEVEL FLOW WILL PRODUCE
PULSING ACTIVITY AND SO CELL WILL HAVE A HARD TIME MOVING OFF THE
FOOTHILLS.

THE UPPER LOW MOVES INTO COLORADO ON SATURDAY AND PUSHES THE
EASTERN ENERGY INTO SOUTHEAST MONTANA. THE GFS WAS STRONGER AND
FARTHER EAST WITH THIS ENERGY AND THUS HAS MORE QPF OVER SOUTHEAST
MONTANA. DID RAISE POPS OVER THE SOUTHEAST AS EVEN THE FARTHER
EAST ECMWF BROUGHT FORCING IN. UPSLOPE FLOW WILL KEEP SCATTERED
SHOWERS GOING OVER WESTERN AND CENTRAL ZONES WITH THE HIGHEST POPS
OVER THE WEST. ENOUGH INSTABILITY FOR THUNDER BUT SHOULD BE
LIMITED. MORE CLOUDS AND NORTHEAST WINDS AT 850MB WILL PROVIDE A
COOLER DAY ON SATURDAY. HIGHS TODAY SHOULD BE AROUND 70...WITH 60S
ON SATURDAY. TWH

.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...

SUNDAY...A LOW OVER THE DAKOTAS WILL CONTINUE TO PUSH EAST. THIS
WILL CONTINUE SLIGHT RAIN CHANCES ACROSS THE AREA...WITH BETTER
CHANCES FROM MILES CITY AND BROADUS EAST...AS PRECIP WRAPS AROUND
THE BACKSIDE OF THE LOW. THE GFS IS MUCH MORE AGGRESSIVE WITH
GENERATING QPF THAN THE ECMWF. GIVEN HOW THE GFS SEEMS TO HAS BEEN
OVERLY AGGRESSIVE WITH SEVERAL PAST SYSTEMS...NOT OVERLY CONFIDENT
WITH ITS AMOUNTS.

AFTER SOME BRIEF...WEAK RIDGING MONDAY INTO TUESDAY...ANOTHER LOW
SETS UP OVER THE PACIFIC NORTHWEST. THE GFS IS MUCH SLOWER AT
PROGRESSING THIS SYSTEM THAN THE EC. WITH EITHER SOLUTION...THE
AREA LOOKS TO SEE UNSETTLE SOUTHWEST FLOW ALOFT ALONG WITH EASTERLY
SURFACE FLOW. THIS WILL SEE PWAT VALUES INCREASING ACROSS THE
AREA. THOUGH THE REMAINDER OF THE EXTEND THERE WILL BE SLIGHT
CHANCES FOR RAIN ACROSS THE AREA...WITH THE HIGHEST CHANCES OVER
THE MOUNTAINS. GIVEN THE HIGHER PWATS...HEAVY RAIN IS A
POSSIBILITY. SOME INSTABILITY EXISTS DURING THE AFTERNOONS...SO
CANNOT RULE OUT AN ISOLATED THUNDERSTORM.

TEMPERATURES WILL GENERALLY BE NEAR SEASONAL NORMALS THROUGH THE
EXTENDED ALTHOUGH SUNDAY WILL BE COOLER AS THE LOW DEPARTS THE
AREA. REIMER


&&

.AVIATION...

EXPECT VFR CONDITIONS OVER THE NEXT 24 HOURS. SOME AFTERNOON
THUNDERSTORMS ARE POSSIBLE MOSTLY OVER THE MOUNTAINS...AND WILL
LIKELY DISSIPATE AFTER MOVING OFF THE HIGHER TERRAIN. SOME BRIEF
MVFR TO IFR CONDITIONS ALONG WITH GUSTY WINDS ARE POSSIBLE WITH
THESE THUNDERSTORMS. REIMER
&&

.PRELIMINARY POINT TEMP/POPS...

    TDY SAT     SUN     MON     TUE     WED     THU
-------------------------------------------------------
BIL 072 046/064 046/060 045/070 047/072 048/071 049/071
    3/T 23/T    23/T    32/T    23/T    33/T    33/T
LVM 067 044/062 042/061 040/067 043/068 043/066 044/069
    4/T 35/T    33/T    33/T    34/T    44/T    43/T
HDN 073 045/065 046/061 045/071 046/074 048/074 048/074
    3/T 23/T    33/T    32/T    23/T    33/T    33/T
MLS 073 046/064 046/062 047/067 046/073 049/072 049/071
    1/N 13/T    45/T    43/T    32/T    33/T    33/T
4BQ 069 043/059 046/058 046/065 045/072 048/071 048/070
    2/T 25/T    56/T    53/T    33/T    33/T    34/T
BHK 069 042/060 044/061 046/065 043/069 046/070 047/069
    1/N 15/T    47/T    65/T    43/T    33/T    33/T
SHR 065 041/059 043/056 041/065 042/070 045/070 045/069
    3/T 25/T    55/T    33/T    34/T    43/T    33/T

&&

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

&&

$$
WEATHER.GOV/BILLINGS




000
FXUS65 KGGW 221431
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
831 AM MDT FRI MAY 22 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SUNDAY...
GOING FORECAST IN EXCELLENT SHAPE.

UPPER LEVEL MOISTURE IN THE FORM OF HIGH CLOUDS ARE MOVING INTO THE
SOUTHERN PORTION OF THE CWA WHILE PRESSURE GRADIENT IS SUPPLYING A
MODERATE WIND TODAY (ENOUGH FOR LWA CONCERNS). NO CHANGES FOR TODAY.

GAVE A GLANCE AT PRECIP CHANCES THROUGH SATURDAY MORNING. NAM AND
GFS SEEM TO HAVE A GOOD HANDLE ON THINGS WHILE 00Z ECMWF LOOKS TOO
WET FOR SATURDAY MORNING. INHERITED FORECAST HAS THIS COVERED
NICELY. TFJ

PREVIOUS DISCUSSION...
THE FORECAST BEGINS WITH NORTHEAST MONTANA STILL UNDER THE HIGH
PRESSURE THAT HAS BROUGHT SEVERAL DAYS OF CLEAR SKIES AND SEASONAL
TO SLIGHTLY ABOVE SEASONAL TEMPERATURES TO THE AREA. BUT A CHANGE
IS OCCURRING. A CLOSED UPPER LOW CENTERED OVER SOUTHERN CALIFORNIA
WILL BE PICKING UP PACIFIC MOISTURE AND EJECTING IT INTO THE
CENTRAL ROCKIES AND PLAINS. THIS LOW WILL SLOWLY LIFT NORTHEAST
THROUGH SUNDAY...ENDING UP OVER THE LOCAL REGION. THE MOVEMENT OF
THIS TROUGH WILL BE NOTICED LOCALLY TODAY AS MID TO HIGH CLOUDS
DRIFT NORTH ACROSS THE AREA...ENDING THE CLEAR SKIES.

TODAY/TONIGHT...AREAS OF INSTABILITY WILL DEVELOP OVER CENTRAL
MONTANA. WEAKER INSTABILITY SPREADS INTO OUR SOUTHWEST ZONES.
THERE IS NOT MUCH TO INITIATE CONVECTION EXCEPT FOR LIFT OVER THE
HILLS. SPC HAS PLACED THAT AREA IN ITS GENERAL THUNDERSTORM AREA.
SO ALTHOUGH NOT EXPECTING MUCH IN THE WAY OF THUNDER OR
SHOWERS...WILL MAINTAIN THE SLIGHT CHANCE THAT HAS BEEN IN PLACE.
A SURFACE GRADIENT IN PLACE WILL AGAIN SET UP A BRISK SOUTHEAST
WIND. MODELS SUGGEST A BIT STRONGER WIND THAN THURSDAY. A LWA IS
IN EFFECT FOR FORT PECK LAKE.

SATURDAY...THE LOW CENTER LIFTS FURTHER INTO THE CENTRAL ROCKIES
WHERE THE MOISTURE FINDS TRIGGERS FOR SHOWERS AND GENERAL
THUNDERSTORMS. BUT WITH NORTHEAST MONTANA REMAINING IN AN AREA
BETWEEN STORMS...ONLY ISOLATED RAIN AND THUNDER IS EXPECTED. BRISK
EAST WINDS WILL CONTINUE.

SATURDAY NIGHT AND SUNDAY...THE LOW LIFTS SUFFICIENTLY NORTH TO
BEGIN AFFECTING THE LOCAL AREA WITH A GREATER CHANCE FOR
SHOWERS...ESPECIALLY IN THE SOUTHEAST ZONES...WITH GREATER QPF ON
SUNDAY AFTERNOON. THE COOLER AIR FROM THE TROUGH WILL TEMPER
TEMPERATURES CLOSER TO NORMAL. SCT

.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...
MODELS HAVE THEIR DIFFERENCES WITH THE UPPER TROUGH/LOW LIFTING
NORTH INTO MONTANA AND THE DAKOTAS SUNDAY NIGHT AND MONDAY. ECMWF
MAINTAINS AN OPEN TROUGH AND KEEPS MOST OF THE MOISTURE TO THE
EAST WHILE THE GFS HAS A CLOSED LOW AND PUSHES MOISTURE FURTHER
WEST INTO EASTERN MONTANA. WILL SPLIT THE DIFFERENCE FOR NOW AND
MAINTAIN HIGHER POPS IN THE EAST.

THE REST OF THE PERIOD... MODELS TIME SYSTEMS DIFFERENTLY BUT EACH
ONE HAS FREQUENT SHORTWAVE TROUGHS GOING THROUGH MONTANA WHICH
WOULD LEAD TO SHOWERS AND THUNDERSTORMS AT TIMES THAT WOULD BE TOO
DIFFICULT TO TIME. WILL MAINTAIN CHANCE/SLIGHT CHANCE OF SHOWERS
AND THUNDERSTORMS THROUGH THE WEEK. FORRESTER

&&

.AVIATION...
FLIGHT CATEGORY: VFR.

SYNOPSIS: MOSTLY CLEAR SKIES THIS MORNING WILL GIVE WAY TO
MID LEVELS CLOUDS INCOMING FROM THE SOUTH THIS AFTERNOON.

AN UPPER LEVEL DISTURBANCE MOVES INTO THE AREA OVERNIGHT AND
SHOULD PROVIDE BELOW MENTION CHANCES FOR RAIN SHOWERS AT KGDV AND
KSDY TERMINALS LASTING THROUGH SUNDAY.

AREA WINDS: SOUTHEAST TO EAST AND INCREASING TO 10 TO 20 KNOTS BY
AFTERNOON. BECOMING EAST AROUND 10 KNOTS TONIGHT.

GAH


&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 8 PM MDT THIS EVENING FOR FORT PECK
LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN
VALLEY...GARFIELD...MCCONE...PETROLEUM.

&&

$$

WEATHER.GOV/GLASGOW






000
FXUS65 KGGW 221431
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
831 AM MDT FRI MAY 22 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SUNDAY...
GOING FORECAST IN EXCELLENT SHAPE.

UPPER LEVEL MOISTURE IN THE FORM OF HIGH CLOUDS ARE MOVING INTO THE
SOUTHERN PORTION OF THE CWA WHILE PRESSURE GRADIENT IS SUPPLYING A
MODERATE WIND TODAY (ENOUGH FOR LWA CONCERNS). NO CHANGES FOR TODAY.

GAVE A GLANCE AT PRECIP CHANCES THROUGH SATURDAY MORNING. NAM AND
GFS SEEM TO HAVE A GOOD HANDLE ON THINGS WHILE 00Z ECMWF LOOKS TOO
WET FOR SATURDAY MORNING. INHERITED FORECAST HAS THIS COVERED
NICELY. TFJ

PREVIOUS DISCUSSION...
THE FORECAST BEGINS WITH NORTHEAST MONTANA STILL UNDER THE HIGH
PRESSURE THAT HAS BROUGHT SEVERAL DAYS OF CLEAR SKIES AND SEASONAL
TO SLIGHTLY ABOVE SEASONAL TEMPERATURES TO THE AREA. BUT A CHANGE
IS OCCURRING. A CLOSED UPPER LOW CENTERED OVER SOUTHERN CALIFORNIA
WILL BE PICKING UP PACIFIC MOISTURE AND EJECTING IT INTO THE
CENTRAL ROCKIES AND PLAINS. THIS LOW WILL SLOWLY LIFT NORTHEAST
THROUGH SUNDAY...ENDING UP OVER THE LOCAL REGION. THE MOVEMENT OF
THIS TROUGH WILL BE NOTICED LOCALLY TODAY AS MID TO HIGH CLOUDS
DRIFT NORTH ACROSS THE AREA...ENDING THE CLEAR SKIES.

TODAY/TONIGHT...AREAS OF INSTABILITY WILL DEVELOP OVER CENTRAL
MONTANA. WEAKER INSTABILITY SPREADS INTO OUR SOUTHWEST ZONES.
THERE IS NOT MUCH TO INITIATE CONVECTION EXCEPT FOR LIFT OVER THE
HILLS. SPC HAS PLACED THAT AREA IN ITS GENERAL THUNDERSTORM AREA.
SO ALTHOUGH NOT EXPECTING MUCH IN THE WAY OF THUNDER OR
SHOWERS...WILL MAINTAIN THE SLIGHT CHANCE THAT HAS BEEN IN PLACE.
A SURFACE GRADIENT IN PLACE WILL AGAIN SET UP A BRISK SOUTHEAST
WIND. MODELS SUGGEST A BIT STRONGER WIND THAN THURSDAY. A LWA IS
IN EFFECT FOR FORT PECK LAKE.

SATURDAY...THE LOW CENTER LIFTS FURTHER INTO THE CENTRAL ROCKIES
WHERE THE MOISTURE FINDS TRIGGERS FOR SHOWERS AND GENERAL
THUNDERSTORMS. BUT WITH NORTHEAST MONTANA REMAINING IN AN AREA
BETWEEN STORMS...ONLY ISOLATED RAIN AND THUNDER IS EXPECTED. BRISK
EAST WINDS WILL CONTINUE.

SATURDAY NIGHT AND SUNDAY...THE LOW LIFTS SUFFICIENTLY NORTH TO
BEGIN AFFECTING THE LOCAL AREA WITH A GREATER CHANCE FOR
SHOWERS...ESPECIALLY IN THE SOUTHEAST ZONES...WITH GREATER QPF ON
SUNDAY AFTERNOON. THE COOLER AIR FROM THE TROUGH WILL TEMPER
TEMPERATURES CLOSER TO NORMAL. SCT

.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...
MODELS HAVE THEIR DIFFERENCES WITH THE UPPER TROUGH/LOW LIFTING
NORTH INTO MONTANA AND THE DAKOTAS SUNDAY NIGHT AND MONDAY. ECMWF
MAINTAINS AN OPEN TROUGH AND KEEPS MOST OF THE MOISTURE TO THE
EAST WHILE THE GFS HAS A CLOSED LOW AND PUSHES MOISTURE FURTHER
WEST INTO EASTERN MONTANA. WILL SPLIT THE DIFFERENCE FOR NOW AND
MAINTAIN HIGHER POPS IN THE EAST.

THE REST OF THE PERIOD... MODELS TIME SYSTEMS DIFFERENTLY BUT EACH
ONE HAS FREQUENT SHORTWAVE TROUGHS GOING THROUGH MONTANA WHICH
WOULD LEAD TO SHOWERS AND THUNDERSTORMS AT TIMES THAT WOULD BE TOO
DIFFICULT TO TIME. WILL MAINTAIN CHANCE/SLIGHT CHANCE OF SHOWERS
AND THUNDERSTORMS THROUGH THE WEEK. FORRESTER

&&

.AVIATION...
FLIGHT CATEGORY: VFR.

SYNOPSIS: MOSTLY CLEAR SKIES THIS MORNING WILL GIVE WAY TO
MID LEVELS CLOUDS INCOMING FROM THE SOUTH THIS AFTERNOON.

AN UPPER LEVEL DISTURBANCE MOVES INTO THE AREA OVERNIGHT AND
SHOULD PROVIDE BELOW MENTION CHANCES FOR RAIN SHOWERS AT KGDV AND
KSDY TERMINALS LASTING THROUGH SUNDAY.

AREA WINDS: SOUTHEAST TO EAST AND INCREASING TO 10 TO 20 KNOTS BY
AFTERNOON. BECOMING EAST AROUND 10 KNOTS TONIGHT.

GAH


&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 8 PM MDT THIS EVENING FOR FORT PECK
LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN
VALLEY...GARFIELD...MCCONE...PETROLEUM.

&&

$$

WEATHER.GOV/GLASGOW





000
FXUS65 KTFX 221126
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
520 AM MDT FRI MAY 22 2015

UPDATED AVIATION DISCUSSION

.DISCUSSION...

TODAY THROUGH SUNDAY...A BROAD CYCLONIC CIRCULATION PRESENTLY MOVING
ASHORE OVER SOUTHERN CALIFORNIA IS FORECAST TO DRIFT SLOWLY
NORTHEAST ACROSS UTAH ON SATURDAY...AND EASTERN WYOMING ON SUNDAY.
THE SYSTEM IS NEARLY EQUIVALENT BAROTROPIC...PROVIDING WEAK SHEAR
BUT JUST ENOUGH INSTABILITY TO SUPPORT WIDESPREAD GENERAL
THUNDERSTORMS. SPECIFIC TO OUR CWA...AFTERNOON SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO REMAIN ACTIVE OVER THE SOUTHWEST
GIVEN DEEPER MOISTURE AND ELEVATED HEATING SOURCES OVER HIGHER
TERRAIN. SMALL HAIL AND GUSTY WINDS WILL AGAIN BE POSSIBLE IN A
FEW OF THESE SLOW MOVING THUNDERSTORMS...ESPECIALLY SATURDAY
AFTERNOON AS MID- LEVEL LAPSE RATES EXCEED 7 DEG/KM. DEEP-LAYER
EASTERLY FLOW CONTINUES OVER NORTH CENTRAL MONTANA. THIS IS
ASSOCIATED WITH DRIER AIR AND A MID-LEVEL INVERSION THAT WILL
SUPPRESS DEVELOPMENT OF SHOWERS IN THIS AREA. HOWEVER...ON
SATURDAY AFTERNOON A SUBTLE INVERTED SHORTWAVE TROUGH ROTATES
AROUND THE PARENT LOW TO HELP WEAKEN THE INVERSION AND ALLOW
SHOWERS AND THUNDERSTORMS TO SPREAD INTO SOUTHERN PORTIONS OF
NORTH CENTRAL MONTANA INCLUDING THE GREAT FALLS AREA. SHOWERS WILL
BE LESS WIDESPREAD ON SUNDAY AS THE PRIMARY TROUGH MOVES FURTHER
WAY INTO THE NORTHERN PLAINS. NUTTER

SUNDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT IN
A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO MIDWEEK.
THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED SUNDAY NIGHT AND
MEMORIAL DAY THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH THEIR
FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER LOW NEAR
VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS IT MOVES
INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER LOW
SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON FRIDAY.
DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR PRECIPITATION
FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM TUESDAY ON OF
SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS THE CANADIAN
BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED THUNDERSTORMS
DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO NOT ANTICIPATE
ANY SEVERE STORMS AT THIS TIME. BLANK

&&

.AVIATION... UPDATED 1125Z.

EXPECT VFR CONDITIONS. THE EXCEPTION TO THIS IS THAT THERE COULD BE
PATCHY FOG IN THE VALLEYS OF SOUTHWEST MONTANA EARLY THIS MORNING.
ALTHOUGH MVFR/IFR VISIBILITIES IN FOG CAN NOT BE TOTALLY RULED OUT
AT KBZN AND KHLN..THINK THE THREAT OF FOG AT THOSE TWO SITES IS LOW
ENOUGH THAT IT WAS NOT INCLUDED IN THE RESPECTIVE TAF FORECASTS.
ISOLATED SHOWERS WILL DEVELOP OVER THE MOUNTAINS OF SOUTHWEST
MONTANA THIS MORNING AND POSSIBLY AS FAR NORTH AS THE LITTLE BELT
MOUNTAINS. SHOWERS WILL INCREASE IN COVERAGE THIS AFTERNOON AND
SCATTERED THUNDERSTORMS WILL DEVELOP. SHOWERS/THUNDERSTORMS WILL
MOVE SLOWLY AND MAINLY WESTWARD. THEY WILL ALSO BE MAINLY NEAR THE
MOUNTAINS. SHOWER AND THUNDERSTORMS ARE UNLIKELY NORTHWEST OF A LINE
FROM KGTF TO KHVR. SHOWERS AND THUNDERSTORMS WILL DIMINISH THIS
EVENING BUT COULD LINGER OVER CENTRAL MONTANA AFTER MIDNIGHT. BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  46  66  43 /  10  20  40  20
CTB  69  41  68  38 /   0  10  20  10
HLN  71  47  67  46 /  20  20  70  40
BZN  68  42  63  41 /  30  20  60  40
WEY  60  35  58  35 /  50  50  60  30
DLN  66  44  64  43 /  30  30  40  30
HVR  73  42  73  41 /  10  20  20  10
LWT  67  45  63  42 /  30  40  50  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS




000
FXUS65 KTFX 221126
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
520 AM MDT FRI MAY 22 2015

UPDATED AVIATION DISCUSSION

.DISCUSSION...

TODAY THROUGH SUNDAY...A BROAD CYCLONIC CIRCULATION PRESENTLY MOVING
ASHORE OVER SOUTHERN CALIFORNIA IS FORECAST TO DRIFT SLOWLY
NORTHEAST ACROSS UTAH ON SATURDAY...AND EASTERN WYOMING ON SUNDAY.
THE SYSTEM IS NEARLY EQUIVALENT BAROTROPIC...PROVIDING WEAK SHEAR
BUT JUST ENOUGH INSTABILITY TO SUPPORT WIDESPREAD GENERAL
THUNDERSTORMS. SPECIFIC TO OUR CWA...AFTERNOON SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO REMAIN ACTIVE OVER THE SOUTHWEST
GIVEN DEEPER MOISTURE AND ELEVATED HEATING SOURCES OVER HIGHER
TERRAIN. SMALL HAIL AND GUSTY WINDS WILL AGAIN BE POSSIBLE IN A
FEW OF THESE SLOW MOVING THUNDERSTORMS...ESPECIALLY SATURDAY
AFTERNOON AS MID- LEVEL LAPSE RATES EXCEED 7 DEG/KM. DEEP-LAYER
EASTERLY FLOW CONTINUES OVER NORTH CENTRAL MONTANA. THIS IS
ASSOCIATED WITH DRIER AIR AND A MID-LEVEL INVERSION THAT WILL
SUPPRESS DEVELOPMENT OF SHOWERS IN THIS AREA. HOWEVER...ON
SATURDAY AFTERNOON A SUBTLE INVERTED SHORTWAVE TROUGH ROTATES
AROUND THE PARENT LOW TO HELP WEAKEN THE INVERSION AND ALLOW
SHOWERS AND THUNDERSTORMS TO SPREAD INTO SOUTHERN PORTIONS OF
NORTH CENTRAL MONTANA INCLUDING THE GREAT FALLS AREA. SHOWERS WILL
BE LESS WIDESPREAD ON SUNDAY AS THE PRIMARY TROUGH MOVES FURTHER
WAY INTO THE NORTHERN PLAINS. NUTTER

SUNDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT IN
A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO MIDWEEK.
THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED SUNDAY NIGHT AND
MEMORIAL DAY THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH THEIR
FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER LOW NEAR
VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS IT MOVES
INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER LOW
SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON FRIDAY.
DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR PRECIPITATION
FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM TUESDAY ON OF
SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS THE CANADIAN
BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED THUNDERSTORMS
DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO NOT ANTICIPATE
ANY SEVERE STORMS AT THIS TIME. BLANK

&&

.AVIATION... UPDATED 1125Z.

EXPECT VFR CONDITIONS. THE EXCEPTION TO THIS IS THAT THERE COULD BE
PATCHY FOG IN THE VALLEYS OF SOUTHWEST MONTANA EARLY THIS MORNING.
ALTHOUGH MVFR/IFR VISIBILITIES IN FOG CAN NOT BE TOTALLY RULED OUT
AT KBZN AND KHLN..THINK THE THREAT OF FOG AT THOSE TWO SITES IS LOW
ENOUGH THAT IT WAS NOT INCLUDED IN THE RESPECTIVE TAF FORECASTS.
ISOLATED SHOWERS WILL DEVELOP OVER THE MOUNTAINS OF SOUTHWEST
MONTANA THIS MORNING AND POSSIBLY AS FAR NORTH AS THE LITTLE BELT
MOUNTAINS. SHOWERS WILL INCREASE IN COVERAGE THIS AFTERNOON AND
SCATTERED THUNDERSTORMS WILL DEVELOP. SHOWERS/THUNDERSTORMS WILL
MOVE SLOWLY AND MAINLY WESTWARD. THEY WILL ALSO BE MAINLY NEAR THE
MOUNTAINS. SHOWER AND THUNDERSTORMS ARE UNLIKELY NORTHWEST OF A LINE
FROM KGTF TO KHVR. SHOWERS AND THUNDERSTORMS WILL DIMINISH THIS
EVENING BUT COULD LINGER OVER CENTRAL MONTANA AFTER MIDNIGHT. BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  46  66  43 /  10  20  40  20
CTB  69  41  68  38 /   0  10  20  10
HLN  71  47  67  46 /  20  20  70  40
BZN  68  42  63  41 /  30  20  60  40
WEY  60  35  58  35 /  50  50  60  30
DLN  66  44  64  43 /  30  30  40  30
HVR  73  42  73  41 /  10  20  20  10
LWT  67  45  63  42 /  30  40  50  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 221126
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
520 AM MDT FRI MAY 22 2015

UPDATED AVIATION DISCUSSION

.DISCUSSION...

TODAY THROUGH SUNDAY...A BROAD CYCLONIC CIRCULATION PRESENTLY MOVING
ASHORE OVER SOUTHERN CALIFORNIA IS FORECAST TO DRIFT SLOWLY
NORTHEAST ACROSS UTAH ON SATURDAY...AND EASTERN WYOMING ON SUNDAY.
THE SYSTEM IS NEARLY EQUIVALENT BAROTROPIC...PROVIDING WEAK SHEAR
BUT JUST ENOUGH INSTABILITY TO SUPPORT WIDESPREAD GENERAL
THUNDERSTORMS. SPECIFIC TO OUR CWA...AFTERNOON SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO REMAIN ACTIVE OVER THE SOUTHWEST
GIVEN DEEPER MOISTURE AND ELEVATED HEATING SOURCES OVER HIGHER
TERRAIN. SMALL HAIL AND GUSTY WINDS WILL AGAIN BE POSSIBLE IN A
FEW OF THESE SLOW MOVING THUNDERSTORMS...ESPECIALLY SATURDAY
AFTERNOON AS MID- LEVEL LAPSE RATES EXCEED 7 DEG/KM. DEEP-LAYER
EASTERLY FLOW CONTINUES OVER NORTH CENTRAL MONTANA. THIS IS
ASSOCIATED WITH DRIER AIR AND A MID-LEVEL INVERSION THAT WILL
SUPPRESS DEVELOPMENT OF SHOWERS IN THIS AREA. HOWEVER...ON
SATURDAY AFTERNOON A SUBTLE INVERTED SHORTWAVE TROUGH ROTATES
AROUND THE PARENT LOW TO HELP WEAKEN THE INVERSION AND ALLOW
SHOWERS AND THUNDERSTORMS TO SPREAD INTO SOUTHERN PORTIONS OF
NORTH CENTRAL MONTANA INCLUDING THE GREAT FALLS AREA. SHOWERS WILL
BE LESS WIDESPREAD ON SUNDAY AS THE PRIMARY TROUGH MOVES FURTHER
WAY INTO THE NORTHERN PLAINS. NUTTER

SUNDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT IN
A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO MIDWEEK.
THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED SUNDAY NIGHT AND
MEMORIAL DAY THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH THEIR
FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER LOW NEAR
VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS IT MOVES
INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER LOW
SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON FRIDAY.
DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR PRECIPITATION
FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM TUESDAY ON OF
SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS THE CANADIAN
BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED THUNDERSTORMS
DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO NOT ANTICIPATE
ANY SEVERE STORMS AT THIS TIME. BLANK

&&

.AVIATION... UPDATED 1125Z.

EXPECT VFR CONDITIONS. THE EXCEPTION TO THIS IS THAT THERE COULD BE
PATCHY FOG IN THE VALLEYS OF SOUTHWEST MONTANA EARLY THIS MORNING.
ALTHOUGH MVFR/IFR VISIBILITIES IN FOG CAN NOT BE TOTALLY RULED OUT
AT KBZN AND KHLN..THINK THE THREAT OF FOG AT THOSE TWO SITES IS LOW
ENOUGH THAT IT WAS NOT INCLUDED IN THE RESPECTIVE TAF FORECASTS.
ISOLATED SHOWERS WILL DEVELOP OVER THE MOUNTAINS OF SOUTHWEST
MONTANA THIS MORNING AND POSSIBLY AS FAR NORTH AS THE LITTLE BELT
MOUNTAINS. SHOWERS WILL INCREASE IN COVERAGE THIS AFTERNOON AND
SCATTERED THUNDERSTORMS WILL DEVELOP. SHOWERS/THUNDERSTORMS WILL
MOVE SLOWLY AND MAINLY WESTWARD. THEY WILL ALSO BE MAINLY NEAR THE
MOUNTAINS. SHOWER AND THUNDERSTORMS ARE UNLIKELY NORTHWEST OF A LINE
FROM KGTF TO KHVR. SHOWERS AND THUNDERSTORMS WILL DIMINISH THIS
EVENING BUT COULD LINGER OVER CENTRAL MONTANA AFTER MIDNIGHT. BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  46  66  43 /  10  20  40  20
CTB  69  41  68  38 /   0  10  20  10
HLN  71  47  67  46 /  20  20  70  40
BZN  68  42  63  41 /  30  20  60  40
WEY  60  35  58  35 /  50  50  60  30
DLN  66  44  64  43 /  30  30  40  30
HVR  73  42  73  41 /  10  20  20  10
LWT  67  45  63  42 /  30  40  50  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 221126
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
520 AM MDT FRI MAY 22 2015

UPDATED AVIATION DISCUSSION

.DISCUSSION...

TODAY THROUGH SUNDAY...A BROAD CYCLONIC CIRCULATION PRESENTLY MOVING
ASHORE OVER SOUTHERN CALIFORNIA IS FORECAST TO DRIFT SLOWLY
NORTHEAST ACROSS UTAH ON SATURDAY...AND EASTERN WYOMING ON SUNDAY.
THE SYSTEM IS NEARLY EQUIVALENT BAROTROPIC...PROVIDING WEAK SHEAR
BUT JUST ENOUGH INSTABILITY TO SUPPORT WIDESPREAD GENERAL
THUNDERSTORMS. SPECIFIC TO OUR CWA...AFTERNOON SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO REMAIN ACTIVE OVER THE SOUTHWEST
GIVEN DEEPER MOISTURE AND ELEVATED HEATING SOURCES OVER HIGHER
TERRAIN. SMALL HAIL AND GUSTY WINDS WILL AGAIN BE POSSIBLE IN A
FEW OF THESE SLOW MOVING THUNDERSTORMS...ESPECIALLY SATURDAY
AFTERNOON AS MID- LEVEL LAPSE RATES EXCEED 7 DEG/KM. DEEP-LAYER
EASTERLY FLOW CONTINUES OVER NORTH CENTRAL MONTANA. THIS IS
ASSOCIATED WITH DRIER AIR AND A MID-LEVEL INVERSION THAT WILL
SUPPRESS DEVELOPMENT OF SHOWERS IN THIS AREA. HOWEVER...ON
SATURDAY AFTERNOON A SUBTLE INVERTED SHORTWAVE TROUGH ROTATES
AROUND THE PARENT LOW TO HELP WEAKEN THE INVERSION AND ALLOW
SHOWERS AND THUNDERSTORMS TO SPREAD INTO SOUTHERN PORTIONS OF
NORTH CENTRAL MONTANA INCLUDING THE GREAT FALLS AREA. SHOWERS WILL
BE LESS WIDESPREAD ON SUNDAY AS THE PRIMARY TROUGH MOVES FURTHER
WAY INTO THE NORTHERN PLAINS. NUTTER

SUNDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT IN
A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO MIDWEEK.
THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED SUNDAY NIGHT AND
MEMORIAL DAY THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH THEIR
FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER LOW NEAR
VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS IT MOVES
INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER LOW
SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON FRIDAY.
DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR PRECIPITATION
FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM TUESDAY ON OF
SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS THE CANADIAN
BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED THUNDERSTORMS
DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO NOT ANTICIPATE
ANY SEVERE STORMS AT THIS TIME. BLANK

&&

.AVIATION... UPDATED 1125Z.

EXPECT VFR CONDITIONS. THE EXCEPTION TO THIS IS THAT THERE COULD BE
PATCHY FOG IN THE VALLEYS OF SOUTHWEST MONTANA EARLY THIS MORNING.
ALTHOUGH MVFR/IFR VISIBILITIES IN FOG CAN NOT BE TOTALLY RULED OUT
AT KBZN AND KHLN..THINK THE THREAT OF FOG AT THOSE TWO SITES IS LOW
ENOUGH THAT IT WAS NOT INCLUDED IN THE RESPECTIVE TAF FORECASTS.
ISOLATED SHOWERS WILL DEVELOP OVER THE MOUNTAINS OF SOUTHWEST
MONTANA THIS MORNING AND POSSIBLY AS FAR NORTH AS THE LITTLE BELT
MOUNTAINS. SHOWERS WILL INCREASE IN COVERAGE THIS AFTERNOON AND
SCATTERED THUNDERSTORMS WILL DEVELOP. SHOWERS/THUNDERSTORMS WILL
MOVE SLOWLY AND MAINLY WESTWARD. THEY WILL ALSO BE MAINLY NEAR THE
MOUNTAINS. SHOWER AND THUNDERSTORMS ARE UNLIKELY NORTHWEST OF A LINE
FROM KGTF TO KHVR. SHOWERS AND THUNDERSTORMS WILL DIMINISH THIS
EVENING BUT COULD LINGER OVER CENTRAL MONTANA AFTER MIDNIGHT. BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  46  66  43 /  10  20  40  20
CTB  69  41  68  38 /   0  10  20  10
HLN  71  47  67  46 /  20  20  70  40
BZN  68  42  63  41 /  30  20  60  40
WEY  60  35  58  35 /  50  50  60  30
DLN  66  44  64  43 /  30  30  40  30
HVR  73  42  73  41 /  10  20  20  10
LWT  67  45  63  42 /  30  40  50  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 221126
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
520 AM MDT FRI MAY 22 2015

UPDATED AVIATION DISCUSSION

.DISCUSSION...

TODAY THROUGH SUNDAY...A BROAD CYCLONIC CIRCULATION PRESENTLY MOVING
ASHORE OVER SOUTHERN CALIFORNIA IS FORECAST TO DRIFT SLOWLY
NORTHEAST ACROSS UTAH ON SATURDAY...AND EASTERN WYOMING ON SUNDAY.
THE SYSTEM IS NEARLY EQUIVALENT BAROTROPIC...PROVIDING WEAK SHEAR
BUT JUST ENOUGH INSTABILITY TO SUPPORT WIDESPREAD GENERAL
THUNDERSTORMS. SPECIFIC TO OUR CWA...AFTERNOON SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO REMAIN ACTIVE OVER THE SOUTHWEST
GIVEN DEEPER MOISTURE AND ELEVATED HEATING SOURCES OVER HIGHER
TERRAIN. SMALL HAIL AND GUSTY WINDS WILL AGAIN BE POSSIBLE IN A
FEW OF THESE SLOW MOVING THUNDERSTORMS...ESPECIALLY SATURDAY
AFTERNOON AS MID- LEVEL LAPSE RATES EXCEED 7 DEG/KM. DEEP-LAYER
EASTERLY FLOW CONTINUES OVER NORTH CENTRAL MONTANA. THIS IS
ASSOCIATED WITH DRIER AIR AND A MID-LEVEL INVERSION THAT WILL
SUPPRESS DEVELOPMENT OF SHOWERS IN THIS AREA. HOWEVER...ON
SATURDAY AFTERNOON A SUBTLE INVERTED SHORTWAVE TROUGH ROTATES
AROUND THE PARENT LOW TO HELP WEAKEN THE INVERSION AND ALLOW
SHOWERS AND THUNDERSTORMS TO SPREAD INTO SOUTHERN PORTIONS OF
NORTH CENTRAL MONTANA INCLUDING THE GREAT FALLS AREA. SHOWERS WILL
BE LESS WIDESPREAD ON SUNDAY AS THE PRIMARY TROUGH MOVES FURTHER
WAY INTO THE NORTHERN PLAINS. NUTTER

SUNDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT IN
A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO MIDWEEK.
THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED SUNDAY NIGHT AND
MEMORIAL DAY THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH THEIR
FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER LOW NEAR
VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS IT MOVES
INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER LOW
SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON FRIDAY.
DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR PRECIPITATION
FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM TUESDAY ON OF
SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS THE CANADIAN
BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED THUNDERSTORMS
DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO NOT ANTICIPATE
ANY SEVERE STORMS AT THIS TIME. BLANK

&&

.AVIATION... UPDATED 1125Z.

EXPECT VFR CONDITIONS. THE EXCEPTION TO THIS IS THAT THERE COULD BE
PATCHY FOG IN THE VALLEYS OF SOUTHWEST MONTANA EARLY THIS MORNING.
ALTHOUGH MVFR/IFR VISIBILITIES IN FOG CAN NOT BE TOTALLY RULED OUT
AT KBZN AND KHLN..THINK THE THREAT OF FOG AT THOSE TWO SITES IS LOW
ENOUGH THAT IT WAS NOT INCLUDED IN THE RESPECTIVE TAF FORECASTS.
ISOLATED SHOWERS WILL DEVELOP OVER THE MOUNTAINS OF SOUTHWEST
MONTANA THIS MORNING AND POSSIBLY AS FAR NORTH AS THE LITTLE BELT
MOUNTAINS. SHOWERS WILL INCREASE IN COVERAGE THIS AFTERNOON AND
SCATTERED THUNDERSTORMS WILL DEVELOP. SHOWERS/THUNDERSTORMS WILL
MOVE SLOWLY AND MAINLY WESTWARD. THEY WILL ALSO BE MAINLY NEAR THE
MOUNTAINS. SHOWER AND THUNDERSTORMS ARE UNLIKELY NORTHWEST OF A LINE
FROM KGTF TO KHVR. SHOWERS AND THUNDERSTORMS WILL DIMINISH THIS
EVENING BUT COULD LINGER OVER CENTRAL MONTANA AFTER MIDNIGHT. BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  46  66  43 /  10  20  40  20
CTB  69  41  68  38 /   0  10  20  10
HLN  71  47  67  46 /  20  20  70  40
BZN  68  42  63  41 /  30  20  60  40
WEY  60  35  58  35 /  50  50  60  30
DLN  66  44  64  43 /  30  30  40  30
HVR  73  42  73  41 /  10  20  20  10
LWT  67  45  63  42 /  30  40  50  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KMSO 220955
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
355 AM MDT FRI MAY 22 2015

.DISCUSSION...Showers and thunderstorms can be expected to develop
again this afternoon and evening, as well as for Saturday. The
coverage of these showers and thunderstorms will likely be in the
same areas where we saw them yesterday. Cloud coverage in central
Idaho will be the deciding factor on how strong the storms do get,
though brief heavy rain and gusty winds will likely be the larger
impacts. Simulated cloud products do indicate that the cloud
coverage for the early part of today will be less extensive than
yesterday, so the potential for more coverage and stronger
thunderstorms today is possible.

Temperatures for the next couple of days will remain warm, with
highs in the mid 70s to low 80s for western Montana and
north-central Idaho. Southwestern Montana and the valleys of
Lemhi county in Idaho can expect slightly cooler temperatures in
the upper 50s and low 60s.

An unsettled weather pattern will continue next week. Naturally
models do not agree on the details and timing systems, but
confidence is good that a low pressure system will affect the
region Monday or Tuesday. There is potential for half an inch to
an inch of rain to affect somewhere in central western Montana
and/or central Idaho. Most solutions bring some, but very little
rain to the parched northwest Montana, and it does not look like
that area will make up its recent precipitation deficit anytime
soon.

&&

.AVIATION...Showers and thunderstorms are expected to develop this
afternoon and evening in much of the same areas as yesterday,
generally along and south of I-90 from KMLP to KMSO to KHLN.
Convection is expected to be begin to develop around 22/2000Z.
Brief heavy rain, gusty winds, and occasional lightning will be
the main impacts from these storms. KBTM and KSMN will be the air
terminals that are more likely to see these impacts from the
thunderstorms. KMSO, will once again be on the northwestern edge
of development and could again see gusty outflow winds. Northwest
Montana will be spared of any showers, however gusty ENE winds can
be expected this afternoon.




&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

$$



000
FXUS65 KMSO 220955
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
355 AM MDT FRI MAY 22 2015

.DISCUSSION...Showers and thunderstorms can be expected to develop
again this afternoon and evening, as well as for Saturday. The
coverage of these showers and thunderstorms will likely be in the
same areas where we saw them yesterday. Cloud coverage in central
Idaho will be the deciding factor on how strong the storms do get,
though brief heavy rain and gusty winds will likely be the larger
impacts. Simulated cloud products do indicate that the cloud
coverage for the early part of today will be less extensive than
yesterday, so the potential for more coverage and stronger
thunderstorms today is possible.

Temperatures for the next couple of days will remain warm, with
highs in the mid 70s to low 80s for western Montana and
north-central Idaho. Southwestern Montana and the valleys of
Lemhi county in Idaho can expect slightly cooler temperatures in
the upper 50s and low 60s.

An unsettled weather pattern will continue next week. Naturally
models do not agree on the details and timing systems, but
confidence is good that a low pressure system will affect the
region Monday or Tuesday. There is potential for half an inch to
an inch of rain to affect somewhere in central western Montana
and/or central Idaho. Most solutions bring some, but very little
rain to the parched northwest Montana, and it does not look like
that area will make up its recent precipitation deficit anytime
soon.

&&

.AVIATION...Showers and thunderstorms are expected to develop this
afternoon and evening in much of the same areas as yesterday,
generally along and south of I-90 from KMLP to KMSO to KHLN.
Convection is expected to be begin to develop around 22/2000Z.
Brief heavy rain, gusty winds, and occasional lightning will be
the main impacts from these storms. KBTM and KSMN will be the air
terminals that are more likely to see these impacts from the
thunderstorms. KMSO, will once again be on the northwestern edge
of development and could again see gusty outflow winds. Northwest
Montana will be spared of any showers, however gusty ENE winds can
be expected this afternoon.




&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

$$




000
FXUS65 KMSO 220955
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
355 AM MDT FRI MAY 22 2015

.DISCUSSION...Showers and thunderstorms can be expected to develop
again this afternoon and evening, as well as for Saturday. The
coverage of these showers and thunderstorms will likely be in the
same areas where we saw them yesterday. Cloud coverage in central
Idaho will be the deciding factor on how strong the storms do get,
though brief heavy rain and gusty winds will likely be the larger
impacts. Simulated cloud products do indicate that the cloud
coverage for the early part of today will be less extensive than
yesterday, so the potential for more coverage and stronger
thunderstorms today is possible.

Temperatures for the next couple of days will remain warm, with
highs in the mid 70s to low 80s for western Montana and
north-central Idaho. Southwestern Montana and the valleys of
Lemhi county in Idaho can expect slightly cooler temperatures in
the upper 50s and low 60s.

An unsettled weather pattern will continue next week. Naturally
models do not agree on the details and timing systems, but
confidence is good that a low pressure system will affect the
region Monday or Tuesday. There is potential for half an inch to
an inch of rain to affect somewhere in central western Montana
and/or central Idaho. Most solutions bring some, but very little
rain to the parched northwest Montana, and it does not look like
that area will make up its recent precipitation deficit anytime
soon.

&&

.AVIATION...Showers and thunderstorms are expected to develop this
afternoon and evening in much of the same areas as yesterday,
generally along and south of I-90 from KMLP to KMSO to KHLN.
Convection is expected to be begin to develop around 22/2000Z.
Brief heavy rain, gusty winds, and occasional lightning will be
the main impacts from these storms. KBTM and KSMN will be the air
terminals that are more likely to see these impacts from the
thunderstorms. KMSO, will once again be on the northwestern edge
of development and could again see gusty outflow winds. Northwest
Montana will be spared of any showers, however gusty ENE winds can
be expected this afternoon.




&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

$$



000
FXUS65 KBYZ 220952
AFDBYZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
352 AM MDT FRI MAY 22 2015

.SHORT TERM...VALID FOR TDY AND SAT...

A DEEP UPPER LOW WAS PUSHING INTO SOUTHERN CALIFORNIA THIS HOUR.
THIS SYSTEM WILL BE RESPONSIBLE FOR OUR RELATIVELY UNSETTLED
FORECAST THROUGH THE WEEKEND. THE UPPER LOW WILL PUSH INTO
SOUTHERN NEVADA EARLY THIS AFTERNOON. A PIECE OF ENERGY OUT AHEAD
OF THE UPPER LOW...OVER NORTHEAST NEW MEXICO...WILL MOVE INTO EAST
CENTRAL WYOMING THIS AFTERNOON. THIS ENERGY WILL SPREAD CLOUDS AND
SHOWERS INTO THE FORECAST AREA. THE HIGHEST POPS WILL BE NEAREST
THE MOUNTAINS WITH UPSLOPE FLOW. ENOUGH INSTABILITY FOR ISOLATED
THUNDERSTORMS...MAINLY WEST. WEAK MID LEVEL FLOW WILL PRODUCE
PULSING ACTIVITY AND SO CELL WILL HAVE A HARD TIME MOVING OFF THE
FOOTHILLS.

THE UPPER LOW MOVES INTO COLORADO ON SATURDAY AND PUSHES THE
EASTERN ENERGY INTO SOUTHEAST MONTANA. THE GFS WAS STRONGER AND
FARTHER EAST WITH THIS ENERGY AND THUS HAS MORE QPF OVER SOUTHEAST
MONTANA. DID RAISE POPS OVER THE SOUTHEAST AS EVEN THE FARTHER
EAST ECMWF BROUGHT FORCING IN. UPSLOPE FLOW WILL KEEP SCATTERED
SHOWERS GOING OVER WESTERN AND CENTRAL ZONES WITH THE HIGHEST POPS
OVER THE WEST. ENOUGH INSTABILITY FOR THUNDER BUT SHOULD BE
LIMITED. MORE CLOUDS AND NORTHEAST WINDS AT 850MB WILL PROVIDE A
COOLER DAY ON SATURDAY. HIGHS TODAY SHOULD BE AROUND 70...WITH 60S
ON SATURDAY. TWH

.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...

SUNDAY...A LOW OVER THE DAKOTAS WILL CONTINUE TO PUSH EAST. THIS
WILL CONTINUE SLIGHT RAIN CHANCES ACROSS THE AREA...WITH BETTER
CHANCES FROM MILES CITY AND BROADUS EAST...AS PRECIP WRAPS AROUND
THE BACKSIDE OF THE LOW. THE GFS IS MUCH MORE AGGRESSIVE WITH
GENERATING QPF THAN THE ECMWF. GIVEN HOW THE GFS SEEMS TO HAS BEEN
OVERLY AGGRESSIVE WITH SEVERAL PAST SYSTEMS...NOT OVERLY CONFIDENT
WITH ITS AMOUNTS.

AFTER SOME BRIEF...WEAK RIDGING MONDAY INTO TUESDAY...ANOTHER LOW
SETS UP OVER THE PACIFIC NORTHWEST. THE GFS IS MUCH SLOWER AT
PROGRESSING THIS SYSTEM THAN THE EC. WITH EITHER SOLUTION...THE
AREA LOOKS TO SEE UNSETTLE SOUTHWEST FLOW ALOFT ALONG WITH EASTERLY
SURFACE FLOW. THIS WILL SEE PWAT VALUES INCREASING ACROSS THE
AREA. THOUGH THE REMAINDER OF THE EXTEND THERE WILL BE SLIGHT
CHANCES FOR RAIN ACROSS THE AREA...WITH THE HIGHEST CHANCES OVER
THE MOUNTAINS. GIVEN THE HIGHER PWATS...HEAVY RAIN IS A
POSSIBILITY. SOME INSTABILITY EXISTS DURING THE AFTERNOONS...SO
CANNOT RULE OUT AN ISOLATED THUNDERSTORM.

TEMPERATURES WILL GENERALLY BE NEAR SEASONAL NORMALS THROUGH THE
EXTENDED ALTHOUGH SUNDAY WILL BE COOLER AS THE LOW DEPARTS THE
AREA. REIMER

&&

.AVIATION...

EXPECT VFR CONDITIONS OVER THE NEXT 24 HOURS. SOME AFTERNOON
THUNDERSTORMS ARE POSSIBLE MOSTLY OVER THE MOUNTAINS...AND WILL
LIKELY DISSIPATE AFTER MOVING OFF THE HIGHER TERRAIN. SOME BRIEF
MVFR TO IFR CONDITIONS ALONG WITH GUSTY WINDS ARE POSSIBLE WITH
THESE THUNDERSTORMS. REIMER

&&

.PRELIMINARY POINT TEMP/POPS...

    TDY SAT     SUN     MON     TUE     WED     THU
-------------------------------------------------------
BIL 072 046/064 046/060 045/070 047/072 048/071 049/071
    3/T 23/T    23/T    32/T    23/T    33/T    33/T
LVM 067 044/062 042/061 040/067 043/068 043/066 044/069
    4/T 35/T    33/T    33/T    34/T    44/T    43/T
HDN 073 045/065 046/061 045/071 046/074 048/074 048/074
    3/T 23/T    33/T    32/T    23/T    33/T    33/T
MLS 073 046/064 046/062 047/067 046/073 049/072 049/071
    1/N 13/T    45/T    43/T    32/T    33/T    33/T
4BQ 069 043/059 046/058 046/065 045/072 048/071 048/070
    2/T 25/T    56/T    53/T    33/T    33/T    34/T
BHK 069 042/060 044/061 046/065 043/069 046/070 047/069
    1/N 15/T    47/T    65/T    43/T    33/T    33/T
SHR 065 041/059 043/056 041/065 042/070 045/070 045/069
    3/T 25/T    55/T    33/T    34/T    43/T    33/T

&&

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

&&

$$
WEATHER.GOV/BILLINGS



000
FXUS65 KBYZ 220952
AFDBYZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
352 AM MDT FRI MAY 22 2015

.SHORT TERM...VALID FOR TDY AND SAT...

A DEEP UPPER LOW WAS PUSHING INTO SOUTHERN CALIFORNIA THIS HOUR.
THIS SYSTEM WILL BE RESPONSIBLE FOR OUR RELATIVELY UNSETTLED
FORECAST THROUGH THE WEEKEND. THE UPPER LOW WILL PUSH INTO
SOUTHERN NEVADA EARLY THIS AFTERNOON. A PIECE OF ENERGY OUT AHEAD
OF THE UPPER LOW...OVER NORTHEAST NEW MEXICO...WILL MOVE INTO EAST
CENTRAL WYOMING THIS AFTERNOON. THIS ENERGY WILL SPREAD CLOUDS AND
SHOWERS INTO THE FORECAST AREA. THE HIGHEST POPS WILL BE NEAREST
THE MOUNTAINS WITH UPSLOPE FLOW. ENOUGH INSTABILITY FOR ISOLATED
THUNDERSTORMS...MAINLY WEST. WEAK MID LEVEL FLOW WILL PRODUCE
PULSING ACTIVITY AND SO CELL WILL HAVE A HARD TIME MOVING OFF THE
FOOTHILLS.

THE UPPER LOW MOVES INTO COLORADO ON SATURDAY AND PUSHES THE
EASTERN ENERGY INTO SOUTHEAST MONTANA. THE GFS WAS STRONGER AND
FARTHER EAST WITH THIS ENERGY AND THUS HAS MORE QPF OVER SOUTHEAST
MONTANA. DID RAISE POPS OVER THE SOUTHEAST AS EVEN THE FARTHER
EAST ECMWF BROUGHT FORCING IN. UPSLOPE FLOW WILL KEEP SCATTERED
SHOWERS GOING OVER WESTERN AND CENTRAL ZONES WITH THE HIGHEST POPS
OVER THE WEST. ENOUGH INSTABILITY FOR THUNDER BUT SHOULD BE
LIMITED. MORE CLOUDS AND NORTHEAST WINDS AT 850MB WILL PROVIDE A
COOLER DAY ON SATURDAY. HIGHS TODAY SHOULD BE AROUND 70...WITH 60S
ON SATURDAY. TWH

.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...

SUNDAY...A LOW OVER THE DAKOTAS WILL CONTINUE TO PUSH EAST. THIS
WILL CONTINUE SLIGHT RAIN CHANCES ACROSS THE AREA...WITH BETTER
CHANCES FROM MILES CITY AND BROADUS EAST...AS PRECIP WRAPS AROUND
THE BACKSIDE OF THE LOW. THE GFS IS MUCH MORE AGGRESSIVE WITH
GENERATING QPF THAN THE ECMWF. GIVEN HOW THE GFS SEEMS TO HAS BEEN
OVERLY AGGRESSIVE WITH SEVERAL PAST SYSTEMS...NOT OVERLY CONFIDENT
WITH ITS AMOUNTS.

AFTER SOME BRIEF...WEAK RIDGING MONDAY INTO TUESDAY...ANOTHER LOW
SETS UP OVER THE PACIFIC NORTHWEST. THE GFS IS MUCH SLOWER AT
PROGRESSING THIS SYSTEM THAN THE EC. WITH EITHER SOLUTION...THE
AREA LOOKS TO SEE UNSETTLE SOUTHWEST FLOW ALOFT ALONG WITH EASTERLY
SURFACE FLOW. THIS WILL SEE PWAT VALUES INCREASING ACROSS THE
AREA. THOUGH THE REMAINDER OF THE EXTEND THERE WILL BE SLIGHT
CHANCES FOR RAIN ACROSS THE AREA...WITH THE HIGHEST CHANCES OVER
THE MOUNTAINS. GIVEN THE HIGHER PWATS...HEAVY RAIN IS A
POSSIBILITY. SOME INSTABILITY EXISTS DURING THE AFTERNOONS...SO
CANNOT RULE OUT AN ISOLATED THUNDERSTORM.

TEMPERATURES WILL GENERALLY BE NEAR SEASONAL NORMALS THROUGH THE
EXTENDED ALTHOUGH SUNDAY WILL BE COOLER AS THE LOW DEPARTS THE
AREA. REIMER

&&

.AVIATION...

EXPECT VFR CONDITIONS OVER THE NEXT 24 HOURS. SOME AFTERNOON
THUNDERSTORMS ARE POSSIBLE MOSTLY OVER THE MOUNTAINS...AND WILL
LIKELY DISSIPATE AFTER MOVING OFF THE HIGHER TERRAIN. SOME BRIEF
MVFR TO IFR CONDITIONS ALONG WITH GUSTY WINDS ARE POSSIBLE WITH
THESE THUNDERSTORMS. REIMER

&&

.PRELIMINARY POINT TEMP/POPS...

    TDY SAT     SUN     MON     TUE     WED     THU
-------------------------------------------------------
BIL 072 046/064 046/060 045/070 047/072 048/071 049/071
    3/T 23/T    23/T    32/T    23/T    33/T    33/T
LVM 067 044/062 042/061 040/067 043/068 043/066 044/069
    4/T 35/T    33/T    33/T    34/T    44/T    43/T
HDN 073 045/065 046/061 045/071 046/074 048/074 048/074
    3/T 23/T    33/T    32/T    23/T    33/T    33/T
MLS 073 046/064 046/062 047/067 046/073 049/072 049/071
    1/N 13/T    45/T    43/T    32/T    33/T    33/T
4BQ 069 043/059 046/058 046/065 045/072 048/071 048/070
    2/T 25/T    56/T    53/T    33/T    33/T    34/T
BHK 069 042/060 044/061 046/065 043/069 046/070 047/069
    1/N 15/T    47/T    65/T    43/T    33/T    33/T
SHR 065 041/059 043/056 041/065 042/070 045/070 045/069
    3/T 25/T    55/T    33/T    34/T    43/T    33/T

&&

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

&&

$$
WEATHER.GOV/BILLINGS




000
FXUS65 KBYZ 220952
AFDBYZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
352 AM MDT FRI MAY 22 2015

.SHORT TERM...VALID FOR TDY AND SAT...

A DEEP UPPER LOW WAS PUSHING INTO SOUTHERN CALIFORNIA THIS HOUR.
THIS SYSTEM WILL BE RESPONSIBLE FOR OUR RELATIVELY UNSETTLED
FORECAST THROUGH THE WEEKEND. THE UPPER LOW WILL PUSH INTO
SOUTHERN NEVADA EARLY THIS AFTERNOON. A PIECE OF ENERGY OUT AHEAD
OF THE UPPER LOW...OVER NORTHEAST NEW MEXICO...WILL MOVE INTO EAST
CENTRAL WYOMING THIS AFTERNOON. THIS ENERGY WILL SPREAD CLOUDS AND
SHOWERS INTO THE FORECAST AREA. THE HIGHEST POPS WILL BE NEAREST
THE MOUNTAINS WITH UPSLOPE FLOW. ENOUGH INSTABILITY FOR ISOLATED
THUNDERSTORMS...MAINLY WEST. WEAK MID LEVEL FLOW WILL PRODUCE
PULSING ACTIVITY AND SO CELL WILL HAVE A HARD TIME MOVING OFF THE
FOOTHILLS.

THE UPPER LOW MOVES INTO COLORADO ON SATURDAY AND PUSHES THE
EASTERN ENERGY INTO SOUTHEAST MONTANA. THE GFS WAS STRONGER AND
FARTHER EAST WITH THIS ENERGY AND THUS HAS MORE QPF OVER SOUTHEAST
MONTANA. DID RAISE POPS OVER THE SOUTHEAST AS EVEN THE FARTHER
EAST ECMWF BROUGHT FORCING IN. UPSLOPE FLOW WILL KEEP SCATTERED
SHOWERS GOING OVER WESTERN AND CENTRAL ZONES WITH THE HIGHEST POPS
OVER THE WEST. ENOUGH INSTABILITY FOR THUNDER BUT SHOULD BE
LIMITED. MORE CLOUDS AND NORTHEAST WINDS AT 850MB WILL PROVIDE A
COOLER DAY ON SATURDAY. HIGHS TODAY SHOULD BE AROUND 70...WITH 60S
ON SATURDAY. TWH

.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...

SUNDAY...A LOW OVER THE DAKOTAS WILL CONTINUE TO PUSH EAST. THIS
WILL CONTINUE SLIGHT RAIN CHANCES ACROSS THE AREA...WITH BETTER
CHANCES FROM MILES CITY AND BROADUS EAST...AS PRECIP WRAPS AROUND
THE BACKSIDE OF THE LOW. THE GFS IS MUCH MORE AGGRESSIVE WITH
GENERATING QPF THAN THE ECMWF. GIVEN HOW THE GFS SEEMS TO HAS BEEN
OVERLY AGGRESSIVE WITH SEVERAL PAST SYSTEMS...NOT OVERLY CONFIDENT
WITH ITS AMOUNTS.

AFTER SOME BRIEF...WEAK RIDGING MONDAY INTO TUESDAY...ANOTHER LOW
SETS UP OVER THE PACIFIC NORTHWEST. THE GFS IS MUCH SLOWER AT
PROGRESSING THIS SYSTEM THAN THE EC. WITH EITHER SOLUTION...THE
AREA LOOKS TO SEE UNSETTLE SOUTHWEST FLOW ALOFT ALONG WITH EASTERLY
SURFACE FLOW. THIS WILL SEE PWAT VALUES INCREASING ACROSS THE
AREA. THOUGH THE REMAINDER OF THE EXTEND THERE WILL BE SLIGHT
CHANCES FOR RAIN ACROSS THE AREA...WITH THE HIGHEST CHANCES OVER
THE MOUNTAINS. GIVEN THE HIGHER PWATS...HEAVY RAIN IS A
POSSIBILITY. SOME INSTABILITY EXISTS DURING THE AFTERNOONS...SO
CANNOT RULE OUT AN ISOLATED THUNDERSTORM.

TEMPERATURES WILL GENERALLY BE NEAR SEASONAL NORMALS THROUGH THE
EXTENDED ALTHOUGH SUNDAY WILL BE COOLER AS THE LOW DEPARTS THE
AREA. REIMER

&&

.AVIATION...

EXPECT VFR CONDITIONS OVER THE NEXT 24 HOURS. SOME AFTERNOON
THUNDERSTORMS ARE POSSIBLE MOSTLY OVER THE MOUNTAINS...AND WILL
LIKELY DISSIPATE AFTER MOVING OFF THE HIGHER TERRAIN. SOME BRIEF
MVFR TO IFR CONDITIONS ALONG WITH GUSTY WINDS ARE POSSIBLE WITH
THESE THUNDERSTORMS. REIMER

&&

.PRELIMINARY POINT TEMP/POPS...

    TDY SAT     SUN     MON     TUE     WED     THU
-------------------------------------------------------
BIL 072 046/064 046/060 045/070 047/072 048/071 049/071
    3/T 23/T    23/T    32/T    23/T    33/T    33/T
LVM 067 044/062 042/061 040/067 043/068 043/066 044/069
    4/T 35/T    33/T    33/T    34/T    44/T    43/T
HDN 073 045/065 046/061 045/071 046/074 048/074 048/074
    3/T 23/T    33/T    32/T    23/T    33/T    33/T
MLS 073 046/064 046/062 047/067 046/073 049/072 049/071
    1/N 13/T    45/T    43/T    32/T    33/T    33/T
4BQ 069 043/059 046/058 046/065 045/072 048/071 048/070
    2/T 25/T    56/T    53/T    33/T    33/T    34/T
BHK 069 042/060 044/061 046/065 043/069 046/070 047/069
    1/N 15/T    47/T    65/T    43/T    33/T    33/T
SHR 065 041/059 043/056 041/065 042/070 045/070 045/069
    3/T 25/T    55/T    33/T    34/T    43/T    33/T

&&

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

&&

$$
WEATHER.GOV/BILLINGS



000
FXUS65 KTFX 220951
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
351 AM MDT FRI MAY 22 2015

.DISCUSSION...

TODAY THROUGH SUNDAY...A BROAD CYCLONIC CIRCULATION PRESENTLY MOVING
ASHORE OVER SOUTHERN CALIFORNIA IS FORECAST TO DRIFT SLOWLY
NORTHEAST ACROSS UTAH ON SATURDAY...AND EASTERN WYOMING ON SUNDAY.
THE SYSTEM IS NEARLY EQUIVALENT BAROTROPIC...PROVIDING WEAK SHEAR
BUT JUST ENOUGH INSTABILITY TO SUPPORT WIDESPREAD GENERAL
THUNDERSTORMS. SPECIFIC TO OUR CWA...AFTERNOON SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO REMAIN ACTIVE OVER THE SOUTHWEST
GIVEN DEEPER MOISTURE AND ELEVATED HEATING SOURCES OVER HIGHER
TERRAIN. SMALL HAIL AND GUSTY WINDS WILL AGAIN BE POSSIBLE IN A
FEW OF THESE SLOW MOVING THUNDERSTORMS...ESPECIALLY SATURDAY
AFTERNOON AS MID- LEVEL LAPSE RATES EXCEED 7 DEG/KM. DEEP-LAYER
EASTERLY FLOW CONTINUES OVER NORTH CENTRAL MONTANA. THIS IS
ASSOCIATED WITH DRIER AIR AND A MID-LEVEL INVERSION THAT WILL
SUPPRESS DEVELOPMENT OF SHOWERS IN THIS AREA. HOWEVER...ON
SATURDAY AFTERNOON A SUBTLE INVERTED SHORTWAVE TROUGH ROTATES
AROUND THE PARENT LOW TO HELP WEAKEN THE INVERSION AND ALLOW
SHOWERS AND THUNDERSTORMS TO SPREAD INTO SOUTHERN PORTIONS OF
NORTH CENTRAL MONTANA INCLUDING THE GREAT FALLS AREA. SHOWERS WILL
BE LESS WIDESPREAD ON SUNDAY AS THE PRIMARY TROUGH MOVES FURTHER
WAY INTO THE NORTHERN PLAINS. NUTTER

SUNDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT IN
A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO MIDWEEK.
THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED SUNDAY NIGHT AND
MEMORIAL DAY THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH THEIR
FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER LOW NEAR
VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS IT MOVES
INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER LOW
SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON FRIDAY.
DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR PRECIPITATION
FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM TUESDAY ON OF
SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS THE CANADIAN
BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED THUNDERSTORMS
DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO NOT ANTICIPATE
ANY SEVERE STORMS AT THIS TIME. BLANK

&&

.AVIATION... UPDATED 0430Z.

EARLIER SCATTERED -SHRA AND ISOLATED -TSRA FROM KHLN TO KDLN HAVE
DISSIPATED.  NOT EXPECTING ANY PRECIPITATION AT KHLN/KBZN OVERNIGHT
THOUGH A NEW ROUND OF -SHRA MAY DEVELOP OVERNIGHT FROM KDLN
SOUTHWARD AS NEXT SWATH OF MOISTURE PUSHES NORTH FROM IDAHO. CENTRAL
MONTANA WILL SEE MOSTLY CLEAR SKIES TONIGHT AND THROUGH FRI MORNING.
EAST TO SOUTHEAST SURFACE WINDS WILL CONTINUE THROUGH TOMORROW AND
MAY BE LOCALLY GUSTY AT TIMES AT THE KLWT AND KHVR TERMINALS. AREA
OF MOISTURE/INSTABILITY SPREADS FURTHER NORTH FRIDAY AFTERNOON WITH
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS POSSIBLE FURTHER NORTH INTO
NORTH CENTRAL MT BY FRIDAY EVENING.
WARANAUSKAS/HOENISCH

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  46  66  43 /  10  20  40  20
CTB  69  41  68  38 /   0  10  20  10
HLN  71  47  67  46 /  20  20  70  40
BZN  68  42  63  41 /  30  20  60  40
WEY  60  35  58  35 /  50  50  60  30
DLN  66  44  64  43 /  30  30  40  30
HVR  73  42  73  41 /  10  20  20  10
LWT  67  45  63  42 /  30  40  50  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 220951
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
351 AM MDT FRI MAY 22 2015

.DISCUSSION...

TODAY THROUGH SUNDAY...A BROAD CYCLONIC CIRCULATION PRESENTLY MOVING
ASHORE OVER SOUTHERN CALIFORNIA IS FORECAST TO DRIFT SLOWLY
NORTHEAST ACROSS UTAH ON SATURDAY...AND EASTERN WYOMING ON SUNDAY.
THE SYSTEM IS NEARLY EQUIVALENT BAROTROPIC...PROVIDING WEAK SHEAR
BUT JUST ENOUGH INSTABILITY TO SUPPORT WIDESPREAD GENERAL
THUNDERSTORMS. SPECIFIC TO OUR CWA...AFTERNOON SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO REMAIN ACTIVE OVER THE SOUTHWEST
GIVEN DEEPER MOISTURE AND ELEVATED HEATING SOURCES OVER HIGHER
TERRAIN. SMALL HAIL AND GUSTY WINDS WILL AGAIN BE POSSIBLE IN A
FEW OF THESE SLOW MOVING THUNDERSTORMS...ESPECIALLY SATURDAY
AFTERNOON AS MID- LEVEL LAPSE RATES EXCEED 7 DEG/KM. DEEP-LAYER
EASTERLY FLOW CONTINUES OVER NORTH CENTRAL MONTANA. THIS IS
ASSOCIATED WITH DRIER AIR AND A MID-LEVEL INVERSION THAT WILL
SUPPRESS DEVELOPMENT OF SHOWERS IN THIS AREA. HOWEVER...ON
SATURDAY AFTERNOON A SUBTLE INVERTED SHORTWAVE TROUGH ROTATES
AROUND THE PARENT LOW TO HELP WEAKEN THE INVERSION AND ALLOW
SHOWERS AND THUNDERSTORMS TO SPREAD INTO SOUTHERN PORTIONS OF
NORTH CENTRAL MONTANA INCLUDING THE GREAT FALLS AREA. SHOWERS WILL
BE LESS WIDESPREAD ON SUNDAY AS THE PRIMARY TROUGH MOVES FURTHER
WAY INTO THE NORTHERN PLAINS. NUTTER

SUNDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT IN
A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO MIDWEEK.
THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED SUNDAY NIGHT AND
MEMORIAL DAY THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH THEIR
FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER LOW NEAR
VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS IT MOVES
INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER LOW
SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON FRIDAY.
DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR PRECIPITATION
FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM TUESDAY ON OF
SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS THE CANADIAN
BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED THUNDERSTORMS
DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO NOT ANTICIPATE
ANY SEVERE STORMS AT THIS TIME. BLANK

&&

.AVIATION... UPDATED 0430Z.

EARLIER SCATTERED -SHRA AND ISOLATED -TSRA FROM KHLN TO KDLN HAVE
DISSIPATED.  NOT EXPECTING ANY PRECIPITATION AT KHLN/KBZN OVERNIGHT
THOUGH A NEW ROUND OF -SHRA MAY DEVELOP OVERNIGHT FROM KDLN
SOUTHWARD AS NEXT SWATH OF MOISTURE PUSHES NORTH FROM IDAHO. CENTRAL
MONTANA WILL SEE MOSTLY CLEAR SKIES TONIGHT AND THROUGH FRI MORNING.
EAST TO SOUTHEAST SURFACE WINDS WILL CONTINUE THROUGH TOMORROW AND
MAY BE LOCALLY GUSTY AT TIMES AT THE KLWT AND KHVR TERMINALS. AREA
OF MOISTURE/INSTABILITY SPREADS FURTHER NORTH FRIDAY AFTERNOON WITH
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS POSSIBLE FURTHER NORTH INTO
NORTH CENTRAL MT BY FRIDAY EVENING.
WARANAUSKAS/HOENISCH

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  46  66  43 /  10  20  40  20
CTB  69  41  68  38 /   0  10  20  10
HLN  71  47  67  46 /  20  20  70  40
BZN  68  42  63  41 /  30  20  60  40
WEY  60  35  58  35 /  50  50  60  30
DLN  66  44  64  43 /  30  30  40  30
HVR  73  42  73  41 /  10  20  20  10
LWT  67  45  63  42 /  30  40  50  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 220951
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
351 AM MDT FRI MAY 22 2015

.DISCUSSION...

TODAY THROUGH SUNDAY...A BROAD CYCLONIC CIRCULATION PRESENTLY MOVING
ASHORE OVER SOUTHERN CALIFORNIA IS FORECAST TO DRIFT SLOWLY
NORTHEAST ACROSS UTAH ON SATURDAY...AND EASTERN WYOMING ON SUNDAY.
THE SYSTEM IS NEARLY EQUIVALENT BAROTROPIC...PROVIDING WEAK SHEAR
BUT JUST ENOUGH INSTABILITY TO SUPPORT WIDESPREAD GENERAL
THUNDERSTORMS. SPECIFIC TO OUR CWA...AFTERNOON SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO REMAIN ACTIVE OVER THE SOUTHWEST
GIVEN DEEPER MOISTURE AND ELEVATED HEATING SOURCES OVER HIGHER
TERRAIN. SMALL HAIL AND GUSTY WINDS WILL AGAIN BE POSSIBLE IN A
FEW OF THESE SLOW MOVING THUNDERSTORMS...ESPECIALLY SATURDAY
AFTERNOON AS MID- LEVEL LAPSE RATES EXCEED 7 DEG/KM. DEEP-LAYER
EASTERLY FLOW CONTINUES OVER NORTH CENTRAL MONTANA. THIS IS
ASSOCIATED WITH DRIER AIR AND A MID-LEVEL INVERSION THAT WILL
SUPPRESS DEVELOPMENT OF SHOWERS IN THIS AREA. HOWEVER...ON
SATURDAY AFTERNOON A SUBTLE INVERTED SHORTWAVE TROUGH ROTATES
AROUND THE PARENT LOW TO HELP WEAKEN THE INVERSION AND ALLOW
SHOWERS AND THUNDERSTORMS TO SPREAD INTO SOUTHERN PORTIONS OF
NORTH CENTRAL MONTANA INCLUDING THE GREAT FALLS AREA. SHOWERS WILL
BE LESS WIDESPREAD ON SUNDAY AS THE PRIMARY TROUGH MOVES FURTHER
WAY INTO THE NORTHERN PLAINS. NUTTER

SUNDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT IN
A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO MIDWEEK.
THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED SUNDAY NIGHT AND
MEMORIAL DAY THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH THEIR
FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER LOW NEAR
VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS IT MOVES
INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER LOW
SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON FRIDAY.
DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR PRECIPITATION
FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM TUESDAY ON OF
SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS THE CANADIAN
BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED THUNDERSTORMS
DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO NOT ANTICIPATE
ANY SEVERE STORMS AT THIS TIME. BLANK

&&

.AVIATION... UPDATED 0430Z.

EARLIER SCATTERED -SHRA AND ISOLATED -TSRA FROM KHLN TO KDLN HAVE
DISSIPATED.  NOT EXPECTING ANY PRECIPITATION AT KHLN/KBZN OVERNIGHT
THOUGH A NEW ROUND OF -SHRA MAY DEVELOP OVERNIGHT FROM KDLN
SOUTHWARD AS NEXT SWATH OF MOISTURE PUSHES NORTH FROM IDAHO. CENTRAL
MONTANA WILL SEE MOSTLY CLEAR SKIES TONIGHT AND THROUGH FRI MORNING.
EAST TO SOUTHEAST SURFACE WINDS WILL CONTINUE THROUGH TOMORROW AND
MAY BE LOCALLY GUSTY AT TIMES AT THE KLWT AND KHVR TERMINALS. AREA
OF MOISTURE/INSTABILITY SPREADS FURTHER NORTH FRIDAY AFTERNOON WITH
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS POSSIBLE FURTHER NORTH INTO
NORTH CENTRAL MT BY FRIDAY EVENING.
WARANAUSKAS/HOENISCH

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  46  66  43 /  10  20  40  20
CTB  69  41  68  38 /   0  10  20  10
HLN  71  47  67  46 /  20  20  70  40
BZN  68  42  63  41 /  30  20  60  40
WEY  60  35  58  35 /  50  50  60  30
DLN  66  44  64  43 /  30  30  40  30
HVR  73  42  73  41 /  10  20  20  10
LWT  67  45  63  42 /  30  40  50  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 220951
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
351 AM MDT FRI MAY 22 2015

.DISCUSSION...

TODAY THROUGH SUNDAY...A BROAD CYCLONIC CIRCULATION PRESENTLY MOVING
ASHORE OVER SOUTHERN CALIFORNIA IS FORECAST TO DRIFT SLOWLY
NORTHEAST ACROSS UTAH ON SATURDAY...AND EASTERN WYOMING ON SUNDAY.
THE SYSTEM IS NEARLY EQUIVALENT BAROTROPIC...PROVIDING WEAK SHEAR
BUT JUST ENOUGH INSTABILITY TO SUPPORT WIDESPREAD GENERAL
THUNDERSTORMS. SPECIFIC TO OUR CWA...AFTERNOON SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO REMAIN ACTIVE OVER THE SOUTHWEST
GIVEN DEEPER MOISTURE AND ELEVATED HEATING SOURCES OVER HIGHER
TERRAIN. SMALL HAIL AND GUSTY WINDS WILL AGAIN BE POSSIBLE IN A
FEW OF THESE SLOW MOVING THUNDERSTORMS...ESPECIALLY SATURDAY
AFTERNOON AS MID- LEVEL LAPSE RATES EXCEED 7 DEG/KM. DEEP-LAYER
EASTERLY FLOW CONTINUES OVER NORTH CENTRAL MONTANA. THIS IS
ASSOCIATED WITH DRIER AIR AND A MID-LEVEL INVERSION THAT WILL
SUPPRESS DEVELOPMENT OF SHOWERS IN THIS AREA. HOWEVER...ON
SATURDAY AFTERNOON A SUBTLE INVERTED SHORTWAVE TROUGH ROTATES
AROUND THE PARENT LOW TO HELP WEAKEN THE INVERSION AND ALLOW
SHOWERS AND THUNDERSTORMS TO SPREAD INTO SOUTHERN PORTIONS OF
NORTH CENTRAL MONTANA INCLUDING THE GREAT FALLS AREA. SHOWERS WILL
BE LESS WIDESPREAD ON SUNDAY AS THE PRIMARY TROUGH MOVES FURTHER
WAY INTO THE NORTHERN PLAINS. NUTTER

SUNDAY NIGHT THROUGH FRIDAY...MODELS CONTINUE TO BE IN AGREEMENT IN
A GENERAL SENSE WITH PRECIPITATION TRENDS AT LEAST INTO MIDWEEK.
THAT IS SHOWER ACTIVITY SHOULD BE MAINLY ISOLATED SUNDAY NIGHT AND
MEMORIAL DAY THEN PICK UP SOME INTO MIDWEEK. WITHIN A PARTICULAR
MODEL THERE IS GENERAL CONSISTENCY FROM RUN-TO-RUN BUT THE GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES BETWEEN EACH OTHER WITH THEIR
FORECASTS ALOFT. LIKE LAST NIGHT THE ECMWF TAKES AN UPPER LOW NEAR
VANCOUVER ISLAND SUNDAY NIGHT SOUTHEAST AND WEAKENS IT AS IT MOVES
INTO CENTRAL MONTANA BY MID-WEEK. THE GFS TAKES THE UPPER LOW
SOUTHEAST EVER SO SLOWLY AND THEN FOR A PERIOD HAS IT QUASI-
STATIONARY BEFORE WEAKENING IT AND MOVING IT INTO MONTANA ON FRIDAY.
DUE TO MODEL DIFFERENCES WITH DETAILS OF THEIR PRECIPITATION
FORECASTS WILL GO WITH THE BROADBRUSH IDEA FROM TUESDAY ON OF
SCATTERED SHOWERS EXCEPT ISOLATED SHOWERS TOWARDS THE CANADIAN
BORDER. OVER THE FORECAST AREA THERE WILL BE ISOLATED THUNDERSTORMS
DURING THE LATE AFTERNOON AND EARLY EVENING BUT DO NOT ANTICIPATE
ANY SEVERE STORMS AT THIS TIME. BLANK

&&

.AVIATION... UPDATED 0430Z.

EARLIER SCATTERED -SHRA AND ISOLATED -TSRA FROM KHLN TO KDLN HAVE
DISSIPATED.  NOT EXPECTING ANY PRECIPITATION AT KHLN/KBZN OVERNIGHT
THOUGH A NEW ROUND OF -SHRA MAY DEVELOP OVERNIGHT FROM KDLN
SOUTHWARD AS NEXT SWATH OF MOISTURE PUSHES NORTH FROM IDAHO. CENTRAL
MONTANA WILL SEE MOSTLY CLEAR SKIES TONIGHT AND THROUGH FRI MORNING.
EAST TO SOUTHEAST SURFACE WINDS WILL CONTINUE THROUGH TOMORROW AND
MAY BE LOCALLY GUSTY AT TIMES AT THE KLWT AND KHVR TERMINALS. AREA
OF MOISTURE/INSTABILITY SPREADS FURTHER NORTH FRIDAY AFTERNOON WITH
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS POSSIBLE FURTHER NORTH INTO
NORTH CENTRAL MT BY FRIDAY EVENING.
WARANAUSKAS/HOENISCH

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  46  66  43 /  10  20  40  20
CTB  69  41  68  38 /   0  10  20  10
HLN  71  47  67  46 /  20  20  70  40
BZN  68  42  63  41 /  30  20  60  40
WEY  60  35  58  35 /  50  50  60  30
DLN  66  44  64  43 /  30  30  40  30
HVR  73  42  73  41 /  10  20  20  10
LWT  67  45  63  42 /  30  40  50  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KGGW 220901
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
301 AM MDT FRI MAY 22 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SUNDAY...

THE FORECAST BEGINS WITH NORTHEAST MONTANA STILL UNDER THE HIGH
PRESSURE THAT HAS BROUGHT SEVERAL DAYS OF CLEAR SKIES AND SEASONAL
TO SLIGHTLY ABOVE SEASONAL TEMPERATURES TO THE AREA. BUT A CHANGE
IS OCCURRING. A CLOSED UPPER LOW CENTERED OVER SOUTHERN CALIFORNIA
WILL BE PICKING UP PACIFIC MOISTURE AND EJECTING IT INTO THE
CENTRAL ROCKIES AND PLAINS. THIS LOW WILL SLOWLY LIFT NORTHEAST
THROUGH SUNDAY...ENDING UP OVER THE LOCAL REGION. THE MOVEMENT OF
THIS TROUGH WILL BE NOTICED LOCALLY TODAY AS MID TO HIGH CLOUDS
DRIFT NORTH ACROSS THE AREA...ENDING THE CLEAR SKIES.

TODAY/TONIGHT...AREAS OF INSTABILITY WILL DEVELOP OVER CENTRAL
MONTANA. WEAKER INSTABILITY SPREADS INTO OUR SOUTHWEST ZONES.
THERE IS NOT MUCH TO INITIATE CONVECTION EXCEPT FOR LIFT OVER THE
HILLS. SPC HAS PLACED THAT AREA IN ITS GENERAL THUNDERSTORM AREA.
SO ALTHOUGH NOT EXPECTING MUCH IN THE WAY OF THUNDER OR
SHOWERS...WILL MAINTAIN THE SLIGHT CHANCE THAT HAS BEEN IN PLACE.
A SURFACE GRADIENT IN PLACE WILL AGAIN SET UP A BRISK SOUTHEAST
WIND. MODELS SUGGEST A BIT STRONGER WIND THAN THURSDAY. A LWA IS
IN EFFECT FOR FORT PECK LAKE.

SATURDAY...THE LOW CENTER LIFTS FURTHER INTO THE CENTRAL ROCKIES
WHERE THE MOISTURE FINDS TRIGGERS FOR SHOWERS AND GENERAL
THUNDERSTORMS. BUT WITH NORTHEAST MONTANA REMAINING IN AN AREA
BETWEEN STORMS...ONLY ISOLATED RAIN AND THUNDER IS EXPECTED. BRISK
EAST WINDS WILL CONTINUE.

SATURDAY NIGHT AND SUNDAY...THE LOW LIFTS SUFFICIENTLY NORTH TO
BEGIN AFFECTING THE LOCAL AREA WITH A GREATER CHANCE FOR
SHOWERS...ESPECIALLY IN THE SOUTHEAST ZONES...WITH GREATER QPF ON
SUNDAY AFTERNOON. THE COOLER AIR FROM THE TROUGH WILL TEMPER
TEMPERATURES CLOSER TO NORMAL. SCT

.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...
MODELS HAVE THEIR DIFFERENCES WITH THE UPPER TROUGH/LOW LIFTING
NORTH INTO MONTANA AND THE DAKOTAS SUNDAY NIGHT AND MONDAY. ECMWF
MAINTAINS AN OPEN TROUGH AND KEEPS MOST OF THE MOISTURE TO THE
EAST WHILE THE GFS HAS A CLOSED LOW AND PUSHES MOISTURE FURTHER
WEST INTO EASTERN MONTANA. WILL SPLIT THE DIFFERENCE FOR NOW AND
MAINTAIN HIGHER POPS IN THE EAST.

THE REST OF THE PERIOD...MODELS TIME SYSTEMS DIFFERENTLY BUT EACH
ONE HAS FREQUENT SHORTWAVE TROUGHS GOING THROUGH MONTANA WHICH
WOULD LEAD TO SHOWERS AND THUNDERSTORMS AT TIMES THAT WOULD BE TOO
DIFFICULT TO TIME. WILL MAINTAIN CHANCE/SLIGHT CHANCE OF SHOWERS
AND THUNDERSTORMS THROUGH THE WEEK. FORRESTER

&&

.AVIATION...
VFR.

MOSTLY CLEAR SKIES THIS MORNING WILL GIVE WAY TO INCREASING HIGH
CLOUDS THIS AFTERNOON. SOUTHEAST WINDS WILL INCREASE TO 10 TO 20
KNOTS BY AFTERNOON. CLOUDS WILL CONTINUE TO INCREASE TONIGHT AS AN
UPPER LEVEL DISTURBANCE MOVES INTO THE AREA FROM THE WEST. LOOK FOR
EAST WINDS TO CONTINUE AS AROUND 10 KNOTS.


&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM 11 AM THIS MORNING TO 8 PM MDT THIS
EVENING FOR FORT PECK LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...
CENTRAL AND SOUTHERN VALLEY...GARFIELD...MCCONE...PETROLEUM.

&&

$$

WEATHER.GOV/GLASGOW





000
FXUS65 KGGW 220901
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
301 AM MDT FRI MAY 22 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SUNDAY...

THE FORECAST BEGINS WITH NORTHEAST MONTANA STILL UNDER THE HIGH
PRESSURE THAT HAS BROUGHT SEVERAL DAYS OF CLEAR SKIES AND SEASONAL
TO SLIGHTLY ABOVE SEASONAL TEMPERATURES TO THE AREA. BUT A CHANGE
IS OCCURRING. A CLOSED UPPER LOW CENTERED OVER SOUTHERN CALIFORNIA
WILL BE PICKING UP PACIFIC MOISTURE AND EJECTING IT INTO THE
CENTRAL ROCKIES AND PLAINS. THIS LOW WILL SLOWLY LIFT NORTHEAST
THROUGH SUNDAY...ENDING UP OVER THE LOCAL REGION. THE MOVEMENT OF
THIS TROUGH WILL BE NOTICED LOCALLY TODAY AS MID TO HIGH CLOUDS
DRIFT NORTH ACROSS THE AREA...ENDING THE CLEAR SKIES.

TODAY/TONIGHT...AREAS OF INSTABILITY WILL DEVELOP OVER CENTRAL
MONTANA. WEAKER INSTABILITY SPREADS INTO OUR SOUTHWEST ZONES.
THERE IS NOT MUCH TO INITIATE CONVECTION EXCEPT FOR LIFT OVER THE
HILLS. SPC HAS PLACED THAT AREA IN ITS GENERAL THUNDERSTORM AREA.
SO ALTHOUGH NOT EXPECTING MUCH IN THE WAY OF THUNDER OR
SHOWERS...WILL MAINTAIN THE SLIGHT CHANCE THAT HAS BEEN IN PLACE.
A SURFACE GRADIENT IN PLACE WILL AGAIN SET UP A BRISK SOUTHEAST
WIND. MODELS SUGGEST A BIT STRONGER WIND THAN THURSDAY. A LWA IS
IN EFFECT FOR FORT PECK LAKE.

SATURDAY...THE LOW CENTER LIFTS FURTHER INTO THE CENTRAL ROCKIES
WHERE THE MOISTURE FINDS TRIGGERS FOR SHOWERS AND GENERAL
THUNDERSTORMS. BUT WITH NORTHEAST MONTANA REMAINING IN AN AREA
BETWEEN STORMS...ONLY ISOLATED RAIN AND THUNDER IS EXPECTED. BRISK
EAST WINDS WILL CONTINUE.

SATURDAY NIGHT AND SUNDAY...THE LOW LIFTS SUFFICIENTLY NORTH TO
BEGIN AFFECTING THE LOCAL AREA WITH A GREATER CHANCE FOR
SHOWERS...ESPECIALLY IN THE SOUTHEAST ZONES...WITH GREATER QPF ON
SUNDAY AFTERNOON. THE COOLER AIR FROM THE TROUGH WILL TEMPER
TEMPERATURES CLOSER TO NORMAL. SCT

.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...
MODELS HAVE THEIR DIFFERENCES WITH THE UPPER TROUGH/LOW LIFTING
NORTH INTO MONTANA AND THE DAKOTAS SUNDAY NIGHT AND MONDAY. ECMWF
MAINTAINS AN OPEN TROUGH AND KEEPS MOST OF THE MOISTURE TO THE
EAST WHILE THE GFS HAS A CLOSED LOW AND PUSHES MOISTURE FURTHER
WEST INTO EASTERN MONTANA. WILL SPLIT THE DIFFERENCE FOR NOW AND
MAINTAIN HIGHER POPS IN THE EAST.

THE REST OF THE PERIOD...MODELS TIME SYSTEMS DIFFERENTLY BUT EACH
ONE HAS FREQUENT SHORTWAVE TROUGHS GOING THROUGH MONTANA WHICH
WOULD LEAD TO SHOWERS AND THUNDERSTORMS AT TIMES THAT WOULD BE TOO
DIFFICULT TO TIME. WILL MAINTAIN CHANCE/SLIGHT CHANCE OF SHOWERS
AND THUNDERSTORMS THROUGH THE WEEK. FORRESTER

&&

.AVIATION...
VFR.

MOSTLY CLEAR SKIES THIS MORNING WILL GIVE WAY TO INCREASING HIGH
CLOUDS THIS AFTERNOON. SOUTHEAST WINDS WILL INCREASE TO 10 TO 20
KNOTS BY AFTERNOON. CLOUDS WILL CONTINUE TO INCREASE TONIGHT AS AN
UPPER LEVEL DISTURBANCE MOVES INTO THE AREA FROM THE WEST. LOOK FOR
EAST WINDS TO CONTINUE AS AROUND 10 KNOTS.


&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM 11 AM THIS MORNING TO 8 PM MDT THIS
EVENING FOR FORT PECK LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...
CENTRAL AND SOUTHERN VALLEY...GARFIELD...MCCONE...PETROLEUM.

&&

$$

WEATHER.GOV/GLASGOW





000
FXUS65 KGGW 220901
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
301 AM MDT FRI MAY 22 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SUNDAY...

THE FORECAST BEGINS WITH NORTHEAST MONTANA STILL UNDER THE HIGH
PRESSURE THAT HAS BROUGHT SEVERAL DAYS OF CLEAR SKIES AND SEASONAL
TO SLIGHTLY ABOVE SEASONAL TEMPERATURES TO THE AREA. BUT A CHANGE
IS OCCURRING. A CLOSED UPPER LOW CENTERED OVER SOUTHERN CALIFORNIA
WILL BE PICKING UP PACIFIC MOISTURE AND EJECTING IT INTO THE
CENTRAL ROCKIES AND PLAINS. THIS LOW WILL SLOWLY LIFT NORTHEAST
THROUGH SUNDAY...ENDING UP OVER THE LOCAL REGION. THE MOVEMENT OF
THIS TROUGH WILL BE NOTICED LOCALLY TODAY AS MID TO HIGH CLOUDS
DRIFT NORTH ACROSS THE AREA...ENDING THE CLEAR SKIES.

TODAY/TONIGHT...AREAS OF INSTABILITY WILL DEVELOP OVER CENTRAL
MONTANA. WEAKER INSTABILITY SPREADS INTO OUR SOUTHWEST ZONES.
THERE IS NOT MUCH TO INITIATE CONVECTION EXCEPT FOR LIFT OVER THE
HILLS. SPC HAS PLACED THAT AREA IN ITS GENERAL THUNDERSTORM AREA.
SO ALTHOUGH NOT EXPECTING MUCH IN THE WAY OF THUNDER OR
SHOWERS...WILL MAINTAIN THE SLIGHT CHANCE THAT HAS BEEN IN PLACE.
A SURFACE GRADIENT IN PLACE WILL AGAIN SET UP A BRISK SOUTHEAST
WIND. MODELS SUGGEST A BIT STRONGER WIND THAN THURSDAY. A LWA IS
IN EFFECT FOR FORT PECK LAKE.

SATURDAY...THE LOW CENTER LIFTS FURTHER INTO THE CENTRAL ROCKIES
WHERE THE MOISTURE FINDS TRIGGERS FOR SHOWERS AND GENERAL
THUNDERSTORMS. BUT WITH NORTHEAST MONTANA REMAINING IN AN AREA
BETWEEN STORMS...ONLY ISOLATED RAIN AND THUNDER IS EXPECTED. BRISK
EAST WINDS WILL CONTINUE.

SATURDAY NIGHT AND SUNDAY...THE LOW LIFTS SUFFICIENTLY NORTH TO
BEGIN AFFECTING THE LOCAL AREA WITH A GREATER CHANCE FOR
SHOWERS...ESPECIALLY IN THE SOUTHEAST ZONES...WITH GREATER QPF ON
SUNDAY AFTERNOON. THE COOLER AIR FROM THE TROUGH WILL TEMPER
TEMPERATURES CLOSER TO NORMAL. SCT

.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...
MODELS HAVE THEIR DIFFERENCES WITH THE UPPER TROUGH/LOW LIFTING
NORTH INTO MONTANA AND THE DAKOTAS SUNDAY NIGHT AND MONDAY. ECMWF
MAINTAINS AN OPEN TROUGH AND KEEPS MOST OF THE MOISTURE TO THE
EAST WHILE THE GFS HAS A CLOSED LOW AND PUSHES MOISTURE FURTHER
WEST INTO EASTERN MONTANA. WILL SPLIT THE DIFFERENCE FOR NOW AND
MAINTAIN HIGHER POPS IN THE EAST.

THE REST OF THE PERIOD...MODELS TIME SYSTEMS DIFFERENTLY BUT EACH
ONE HAS FREQUENT SHORTWAVE TROUGHS GOING THROUGH MONTANA WHICH
WOULD LEAD TO SHOWERS AND THUNDERSTORMS AT TIMES THAT WOULD BE TOO
DIFFICULT TO TIME. WILL MAINTAIN CHANCE/SLIGHT CHANCE OF SHOWERS
AND THUNDERSTORMS THROUGH THE WEEK. FORRESTER

&&

.AVIATION...
VFR.

MOSTLY CLEAR SKIES THIS MORNING WILL GIVE WAY TO INCREASING HIGH
CLOUDS THIS AFTERNOON. SOUTHEAST WINDS WILL INCREASE TO 10 TO 20
KNOTS BY AFTERNOON. CLOUDS WILL CONTINUE TO INCREASE TONIGHT AS AN
UPPER LEVEL DISTURBANCE MOVES INTO THE AREA FROM THE WEST. LOOK FOR
EAST WINDS TO CONTINUE AS AROUND 10 KNOTS.


&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM 11 AM THIS MORNING TO 8 PM MDT THIS
EVENING FOR FORT PECK LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...
CENTRAL AND SOUTHERN VALLEY...GARFIELD...MCCONE...PETROLEUM.

&&

$$

WEATHER.GOV/GLASGOW






000
FXUS65 KTFX 220431
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1030 PM MDT THU MAY 21 2015

AVIATION SECTION UPDATED

.UPDATE... LATEST RADAR IMAGERY SHOWS RAIN SHOWERS NEAR HELENA AND
PARTS OF BEAVERHEAD COUNTY CONTINUING TO SLOWLY DISSIPATE WHILE
SKIES ARE MOSTLY CLEAR ACROSS THE HILINE AND MOST OF THE CENTRAL MT
COUNTIES.  PRIMARY FORECAST ADJUSTMENT THIS EVENING WAS TO REDUCE
PRECIP CHANCES ACROSS JEFFERSON/BROADWATER/MADISON/GALLATIN COUNTIES
NOW THAT PRECIP HAS ENDED THERE.  PREDICTED OVERNIGHT TEMPERATURES
LOOK GOOD AT THIS TIME.
WARANAUSKAS

&&

.DISCUSSION...

TONIGHT THROUGH SATURDAY...RELATIVELY LIGHT UPPER LEVEL FLOW FROM
THE SOUTHEAST WILL CONTINUE OVERNIGHT BUT IS EXPECTED TO SHIFT
EAST-NORTHEAST AND INCREASE BY SATURDAY. SCATTERED TO NUMEROUS
SHOWERS AND A FEW THUNDERSTORMS CAN BE EXPECTED ACROSS SOUTHWEST
MONTANA THIS AFTERNOON AND EVENING BEFORE TAPERING OFF TO ISOLATED
SHOWERS OVERNIGHT. ISOLATED CONVECTION COULD REACH SOUTHERN PORTIONS
OF CENTRAL MONTANA THIS AFTERNOON AND EVENING AS WELL. HOWEVER,
FROM FRIDAY EVENING THROUGH SATURDAY AFTERNOON SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS SPREAD ACROSS CENTRAL AND NORTH
CENTRAL MONTANA AS WELL. AS HAS BEEN MENTIONED OVER THE LAST FEW
DAYS, I AM NOT EXPECTED ANY SEVERE WEATHER AS CAPE AND SHEAR
REMAIN RELATIVELY WEAK. MPJ

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.AVIATION... UPDATED 0430Z.

EARLIER SCATTERED -SHRA AND ISOLATED -TSRA FROM KHLN TO KDLN HAVE
DISSIPATED.  NOT EXPECTING ANY PRECIPITATION AT KHLN/KBZN OVERNIGHT
THOUGH A NEW ROUND OF -SHRA MAY DEVELOP OVERNIGHT FROM KDLN
SOUTHWARD AS NEXT SWATH OF MOISTURE PUSHES NORTH FROM IDAHO. CENTRAL
MONTANA WILL SEE MOSTLY CLEAR SKIES TONIGHT AND THROUGH FRI MORNING.
EAST TO SOUTHEAST SURFACE WINDS WILL CONTINUE THROUGH TOMORROW AND
MAY BE LOCALLY GUSTY AT TIMES AT THE KLWT AND KHVR TERMINALS. AREA
OF MOISTURE/INSTABILITY SPREADS FURTHER NORTH FRIDAY AFTERNOON WITH
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS POSSIBLE FURTHER NORTH INTO
NORTH CENTRAL MT BY FRIDAY EVENING.
WARANAUSKAS/HOENISCH

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  43  70  46  67 /  10  20  30  40
CTB  37  69  41  68 /   0  10  10  20
HLN  45  72  48  67 /  30  30  30  60
BZN  39  69  42  64 /  30  40  30  50
WEY  32  61  34  58 /  40  50  60  60
DLN  41  66  44  64 /  50  40  30  50
HVR  38  73  43  73 /   0  10  30  20
LWT  41  69  45  64 /   0  40  40  40

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 220431
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1030 PM MDT THU MAY 21 2015

AVIATION SECTION UPDATED

.UPDATE... LATEST RADAR IMAGERY SHOWS RAIN SHOWERS NEAR HELENA AND
PARTS OF BEAVERHEAD COUNTY CONTINUING TO SLOWLY DISSIPATE WHILE
SKIES ARE MOSTLY CLEAR ACROSS THE HILINE AND MOST OF THE CENTRAL MT
COUNTIES.  PRIMARY FORECAST ADJUSTMENT THIS EVENING WAS TO REDUCE
PRECIP CHANCES ACROSS JEFFERSON/BROADWATER/MADISON/GALLATIN COUNTIES
NOW THAT PRECIP HAS ENDED THERE.  PREDICTED OVERNIGHT TEMPERATURES
LOOK GOOD AT THIS TIME.
WARANAUSKAS

&&

.DISCUSSION...

TONIGHT THROUGH SATURDAY...RELATIVELY LIGHT UPPER LEVEL FLOW FROM
THE SOUTHEAST WILL CONTINUE OVERNIGHT BUT IS EXPECTED TO SHIFT
EAST-NORTHEAST AND INCREASE BY SATURDAY. SCATTERED TO NUMEROUS
SHOWERS AND A FEW THUNDERSTORMS CAN BE EXPECTED ACROSS SOUTHWEST
MONTANA THIS AFTERNOON AND EVENING BEFORE TAPERING OFF TO ISOLATED
SHOWERS OVERNIGHT. ISOLATED CONVECTION COULD REACH SOUTHERN PORTIONS
OF CENTRAL MONTANA THIS AFTERNOON AND EVENING AS WELL. HOWEVER,
FROM FRIDAY EVENING THROUGH SATURDAY AFTERNOON SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS SPREAD ACROSS CENTRAL AND NORTH
CENTRAL MONTANA AS WELL. AS HAS BEEN MENTIONED OVER THE LAST FEW
DAYS, I AM NOT EXPECTED ANY SEVERE WEATHER AS CAPE AND SHEAR
REMAIN RELATIVELY WEAK. MPJ

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.AVIATION... UPDATED 0430Z.

EARLIER SCATTERED -SHRA AND ISOLATED -TSRA FROM KHLN TO KDLN HAVE
DISSIPATED.  NOT EXPECTING ANY PRECIPITATION AT KHLN/KBZN OVERNIGHT
THOUGH A NEW ROUND OF -SHRA MAY DEVELOP OVERNIGHT FROM KDLN
SOUTHWARD AS NEXT SWATH OF MOISTURE PUSHES NORTH FROM IDAHO. CENTRAL
MONTANA WILL SEE MOSTLY CLEAR SKIES TONIGHT AND THROUGH FRI MORNING.
EAST TO SOUTHEAST SURFACE WINDS WILL CONTINUE THROUGH TOMORROW AND
MAY BE LOCALLY GUSTY AT TIMES AT THE KLWT AND KHVR TERMINALS. AREA
OF MOISTURE/INSTABILITY SPREADS FURTHER NORTH FRIDAY AFTERNOON WITH
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS POSSIBLE FURTHER NORTH INTO
NORTH CENTRAL MT BY FRIDAY EVENING.
WARANAUSKAS/HOENISCH

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  43  70  46  67 /  10  20  30  40
CTB  37  69  41  68 /   0  10  10  20
HLN  45  72  48  67 /  30  30  30  60
BZN  39  69  42  64 /  30  40  30  50
WEY  32  61  34  58 /  40  50  60  60
DLN  41  66  44  64 /  50  40  30  50
HVR  38  73  43  73 /   0  10  30  20
LWT  41  69  45  64 /   0  40  40  40

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS




000
FXUS65 KTFX 220320
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
915 PM MDT THU MAY 21 2015

.UPDATE... LATEST RADAR IMAGERY SHOWS RAIN SHOWERS NEAR HELENA AND
PARTS OF BEAVERHEAD COUNTY CONTINUING TO SLOWLY DISSIPATE WHILE
SKIES ARE MOSTLY CLEAR ACROSS THE HILINE AND MOST OF THE CENTRAL MT
COUNTIES.  PRIMARY FORECAST ADJUSTMENT THIS EVENING WAS TO REDUCE
PRECIP CHANCES ACROSS JEFFERSON/BROADWATER/MADISON/GALLATIN COUNTIES
NOW THAT PRECIP HAS ENDED THERE.  PREDICTED OVERNIGHT TEMPERATURES
LOOK GOOD AT THIS TIME.
WARANAUSKAS

&&

.DISCUSSION...

TONIGHT THROUGH SATURDAY...RELATIVELY LIGHT UPPER LEVEL FLOW FROM
THE SOUTHEAST WILL CONTINUE OVERNIGHT BUT IS EXPECTED TO SHIFT
EAST-NORTHEAST AND INCREASE BY SATURDAY. SCATTERED TO NUMEROUS
SHOWERS AND A FEW THUNDERSTORMS CAN BE EXPECTED ACROSS SOUTHWEST
MONTANA THIS AFTERNOON AND EVENING BEFORE TAPERING OFF TO ISOLATED
SHOWERS OVERNIGHT. ISOLATED CONVECTION COULD REACH SOUTHERN PORTIONS
OF CENTRAL MONTANA THIS AFTERNOON AND EVENING AS WELL. HOWEVER,
FROM FRIDAY EVENING THROUGH SATURDAY AFTERNOON SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS SPREAD ACROSS CENTRAL AND NORTH
CENTRAL MONTANA AS WELL. AS HAS BEEN MENTIONED OVER THE LAST FEW
DAYS, I AM NOT EXPECTED ANY SEVERE WEATHER AS CAPE AND SHEAR
REMAIN RELATIVELY WEAK. MPJ

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.AVIATION... UPDATED 0000Z.

A RELATIVELY MORE MOIST/UNSTABLE AIRMASS HAS MOVED NORTH INTO SW MT
WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS
EVENING...MAINLY SOUTH OF KHLN TO KGTF. BRIEF MVFR CONDITIONS ARE
POSSIBLE UNDER THESE CELLS THIS EVENING WITH LOCAL TERRAIN
OBSCURATIONS. VFR CONDITIONS WILL PREVAIL OTHERWISE WITH SHOWERS AND
THUNDERSTORMS ENDING BY MIDNIGHT. EAST TO SOUTHEAST SURFACE WINDS
WILL CONTINUE THROUGH TOMORROW AND MAY BE LOCALLY GUSTY AT TIMES AT
THE KLWT AND KHVR TERMINALS. AREA OF MOISTURE/INSTABILITY SPREADS
FURTHER NORTH FRIDAY AFTERNOON WITH SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS POSSIBLE FURTHER NORTH INTO NORTH CENTRAL MT BY FRIDAY
EVENING. HOENISCH

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  43  70  46  67 /  10  20  30  40
CTB  37  69  41  68 /   0  10  10  20
HLN  45  72  48  67 /  30  30  30  60
BZN  39  69  42  64 /  30  40  30  50
WEY  32  61  34  58 /  40  50  60  60
DLN  41  66  44  64 /  50  40  30  50
HVR  38  73  43  73 /   0  10  30  20
LWT  41  69  45  64 /   0  40  40  40

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS




000
FXUS65 KTFX 220320
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
915 PM MDT THU MAY 21 2015

.UPDATE... LATEST RADAR IMAGERY SHOWS RAIN SHOWERS NEAR HELENA AND
PARTS OF BEAVERHEAD COUNTY CONTINUING TO SLOWLY DISSIPATE WHILE
SKIES ARE MOSTLY CLEAR ACROSS THE HILINE AND MOST OF THE CENTRAL MT
COUNTIES.  PRIMARY FORECAST ADJUSTMENT THIS EVENING WAS TO REDUCE
PRECIP CHANCES ACROSS JEFFERSON/BROADWATER/MADISON/GALLATIN COUNTIES
NOW THAT PRECIP HAS ENDED THERE.  PREDICTED OVERNIGHT TEMPERATURES
LOOK GOOD AT THIS TIME.
WARANAUSKAS

&&

.DISCUSSION...

TONIGHT THROUGH SATURDAY...RELATIVELY LIGHT UPPER LEVEL FLOW FROM
THE SOUTHEAST WILL CONTINUE OVERNIGHT BUT IS EXPECTED TO SHIFT
EAST-NORTHEAST AND INCREASE BY SATURDAY. SCATTERED TO NUMEROUS
SHOWERS AND A FEW THUNDERSTORMS CAN BE EXPECTED ACROSS SOUTHWEST
MONTANA THIS AFTERNOON AND EVENING BEFORE TAPERING OFF TO ISOLATED
SHOWERS OVERNIGHT. ISOLATED CONVECTION COULD REACH SOUTHERN PORTIONS
OF CENTRAL MONTANA THIS AFTERNOON AND EVENING AS WELL. HOWEVER,
FROM FRIDAY EVENING THROUGH SATURDAY AFTERNOON SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS SPREAD ACROSS CENTRAL AND NORTH
CENTRAL MONTANA AS WELL. AS HAS BEEN MENTIONED OVER THE LAST FEW
DAYS, I AM NOT EXPECTED ANY SEVERE WEATHER AS CAPE AND SHEAR
REMAIN RELATIVELY WEAK. MPJ

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.AVIATION... UPDATED 0000Z.

A RELATIVELY MORE MOIST/UNSTABLE AIRMASS HAS MOVED NORTH INTO SW MT
WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS
EVENING...MAINLY SOUTH OF KHLN TO KGTF. BRIEF MVFR CONDITIONS ARE
POSSIBLE UNDER THESE CELLS THIS EVENING WITH LOCAL TERRAIN
OBSCURATIONS. VFR CONDITIONS WILL PREVAIL OTHERWISE WITH SHOWERS AND
THUNDERSTORMS ENDING BY MIDNIGHT. EAST TO SOUTHEAST SURFACE WINDS
WILL CONTINUE THROUGH TOMORROW AND MAY BE LOCALLY GUSTY AT TIMES AT
THE KLWT AND KHVR TERMINALS. AREA OF MOISTURE/INSTABILITY SPREADS
FURTHER NORTH FRIDAY AFTERNOON WITH SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS POSSIBLE FURTHER NORTH INTO NORTH CENTRAL MT BY FRIDAY
EVENING. HOENISCH

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  43  70  46  67 /  10  20  30  40
CTB  37  69  41  68 /   0  10  10  20
HLN  45  72  48  67 /  30  30  30  60
BZN  39  69  42  64 /  30  40  30  50
WEY  32  61  34  58 /  40  50  60  60
DLN  41  66  44  64 /  50  40  30  50
HVR  38  73  43  73 /   0  10  30  20
LWT  41  69  45  64 /   0  40  40  40

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS




000
FXUS65 KTFX 220320
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
915 PM MDT THU MAY 21 2015

.UPDATE... LATEST RADAR IMAGERY SHOWS RAIN SHOWERS NEAR HELENA AND
PARTS OF BEAVERHEAD COUNTY CONTINUING TO SLOWLY DISSIPATE WHILE
SKIES ARE MOSTLY CLEAR ACROSS THE HILINE AND MOST OF THE CENTRAL MT
COUNTIES.  PRIMARY FORECAST ADJUSTMENT THIS EVENING WAS TO REDUCE
PRECIP CHANCES ACROSS JEFFERSON/BROADWATER/MADISON/GALLATIN COUNTIES
NOW THAT PRECIP HAS ENDED THERE.  PREDICTED OVERNIGHT TEMPERATURES
LOOK GOOD AT THIS TIME.
WARANAUSKAS

&&

.DISCUSSION...

TONIGHT THROUGH SATURDAY...RELATIVELY LIGHT UPPER LEVEL FLOW FROM
THE SOUTHEAST WILL CONTINUE OVERNIGHT BUT IS EXPECTED TO SHIFT
EAST-NORTHEAST AND INCREASE BY SATURDAY. SCATTERED TO NUMEROUS
SHOWERS AND A FEW THUNDERSTORMS CAN BE EXPECTED ACROSS SOUTHWEST
MONTANA THIS AFTERNOON AND EVENING BEFORE TAPERING OFF TO ISOLATED
SHOWERS OVERNIGHT. ISOLATED CONVECTION COULD REACH SOUTHERN PORTIONS
OF CENTRAL MONTANA THIS AFTERNOON AND EVENING AS WELL. HOWEVER,
FROM FRIDAY EVENING THROUGH SATURDAY AFTERNOON SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS SPREAD ACROSS CENTRAL AND NORTH
CENTRAL MONTANA AS WELL. AS HAS BEEN MENTIONED OVER THE LAST FEW
DAYS, I AM NOT EXPECTED ANY SEVERE WEATHER AS CAPE AND SHEAR
REMAIN RELATIVELY WEAK. MPJ

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.AVIATION... UPDATED 0000Z.

A RELATIVELY MORE MOIST/UNSTABLE AIRMASS HAS MOVED NORTH INTO SW MT
WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS
EVENING...MAINLY SOUTH OF KHLN TO KGTF. BRIEF MVFR CONDITIONS ARE
POSSIBLE UNDER THESE CELLS THIS EVENING WITH LOCAL TERRAIN
OBSCURATIONS. VFR CONDITIONS WILL PREVAIL OTHERWISE WITH SHOWERS AND
THUNDERSTORMS ENDING BY MIDNIGHT. EAST TO SOUTHEAST SURFACE WINDS
WILL CONTINUE THROUGH TOMORROW AND MAY BE LOCALLY GUSTY AT TIMES AT
THE KLWT AND KHVR TERMINALS. AREA OF MOISTURE/INSTABILITY SPREADS
FURTHER NORTH FRIDAY AFTERNOON WITH SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS POSSIBLE FURTHER NORTH INTO NORTH CENTRAL MT BY FRIDAY
EVENING. HOENISCH

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  43  70  46  67 /  10  20  30  40
CTB  37  69  41  68 /   0  10  10  20
HLN  45  72  48  67 /  30  30  30  60
BZN  39  69  42  64 /  30  40  30  50
WEY  32  61  34  58 /  40  50  60  60
DLN  41  66  44  64 /  50  40  30  50
HVR  38  73  43  73 /   0  10  30  20
LWT  41  69  45  64 /   0  40  40  40

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS




000
FXUS65 KTFX 220320
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
915 PM MDT THU MAY 21 2015

.UPDATE... LATEST RADAR IMAGERY SHOWS RAIN SHOWERS NEAR HELENA AND
PARTS OF BEAVERHEAD COUNTY CONTINUING TO SLOWLY DISSIPATE WHILE
SKIES ARE MOSTLY CLEAR ACROSS THE HILINE AND MOST OF THE CENTRAL MT
COUNTIES.  PRIMARY FORECAST ADJUSTMENT THIS EVENING WAS TO REDUCE
PRECIP CHANCES ACROSS JEFFERSON/BROADWATER/MADISON/GALLATIN COUNTIES
NOW THAT PRECIP HAS ENDED THERE.  PREDICTED OVERNIGHT TEMPERATURES
LOOK GOOD AT THIS TIME.
WARANAUSKAS

&&

.DISCUSSION...

TONIGHT THROUGH SATURDAY...RELATIVELY LIGHT UPPER LEVEL FLOW FROM
THE SOUTHEAST WILL CONTINUE OVERNIGHT BUT IS EXPECTED TO SHIFT
EAST-NORTHEAST AND INCREASE BY SATURDAY. SCATTERED TO NUMEROUS
SHOWERS AND A FEW THUNDERSTORMS CAN BE EXPECTED ACROSS SOUTHWEST
MONTANA THIS AFTERNOON AND EVENING BEFORE TAPERING OFF TO ISOLATED
SHOWERS OVERNIGHT. ISOLATED CONVECTION COULD REACH SOUTHERN PORTIONS
OF CENTRAL MONTANA THIS AFTERNOON AND EVENING AS WELL. HOWEVER,
FROM FRIDAY EVENING THROUGH SATURDAY AFTERNOON SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS SPREAD ACROSS CENTRAL AND NORTH
CENTRAL MONTANA AS WELL. AS HAS BEEN MENTIONED OVER THE LAST FEW
DAYS, I AM NOT EXPECTED ANY SEVERE WEATHER AS CAPE AND SHEAR
REMAIN RELATIVELY WEAK. MPJ

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.AVIATION... UPDATED 0000Z.

A RELATIVELY MORE MOIST/UNSTABLE AIRMASS HAS MOVED NORTH INTO SW MT
WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS
EVENING...MAINLY SOUTH OF KHLN TO KGTF. BRIEF MVFR CONDITIONS ARE
POSSIBLE UNDER THESE CELLS THIS EVENING WITH LOCAL TERRAIN
OBSCURATIONS. VFR CONDITIONS WILL PREVAIL OTHERWISE WITH SHOWERS AND
THUNDERSTORMS ENDING BY MIDNIGHT. EAST TO SOUTHEAST SURFACE WINDS
WILL CONTINUE THROUGH TOMORROW AND MAY BE LOCALLY GUSTY AT TIMES AT
THE KLWT AND KHVR TERMINALS. AREA OF MOISTURE/INSTABILITY SPREADS
FURTHER NORTH FRIDAY AFTERNOON WITH SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS POSSIBLE FURTHER NORTH INTO NORTH CENTRAL MT BY FRIDAY
EVENING. HOENISCH

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  43  70  46  67 /  10  20  30  40
CTB  37  69  41  68 /   0  10  10  20
HLN  45  72  48  67 /  30  30  30  60
BZN  39  69  42  64 /  30  40  30  50
WEY  32  61  34  58 /  40  50  60  60
DLN  41  66  44  64 /  50  40  30  50
HVR  38  73  43  73 /   0  10  30  20
LWT  41  69  45  64 /   0  40  40  40

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS




000
FXUS65 KTFX 220320
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
915 PM MDT THU MAY 21 2015

.UPDATE... LATEST RADAR IMAGERY SHOWS RAIN SHOWERS NEAR HELENA AND
PARTS OF BEAVERHEAD COUNTY CONTINUING TO SLOWLY DISSIPATE WHILE
SKIES ARE MOSTLY CLEAR ACROSS THE HILINE AND MOST OF THE CENTRAL MT
COUNTIES.  PRIMARY FORECAST ADJUSTMENT THIS EVENING WAS TO REDUCE
PRECIP CHANCES ACROSS JEFFERSON/BROADWATER/MADISON/GALLATIN COUNTIES
NOW THAT PRECIP HAS ENDED THERE.  PREDICTED OVERNIGHT TEMPERATURES
LOOK GOOD AT THIS TIME.
WARANAUSKAS

&&

.DISCUSSION...

TONIGHT THROUGH SATURDAY...RELATIVELY LIGHT UPPER LEVEL FLOW FROM
THE SOUTHEAST WILL CONTINUE OVERNIGHT BUT IS EXPECTED TO SHIFT
EAST-NORTHEAST AND INCREASE BY SATURDAY. SCATTERED TO NUMEROUS
SHOWERS AND A FEW THUNDERSTORMS CAN BE EXPECTED ACROSS SOUTHWEST
MONTANA THIS AFTERNOON AND EVENING BEFORE TAPERING OFF TO ISOLATED
SHOWERS OVERNIGHT. ISOLATED CONVECTION COULD REACH SOUTHERN PORTIONS
OF CENTRAL MONTANA THIS AFTERNOON AND EVENING AS WELL. HOWEVER,
FROM FRIDAY EVENING THROUGH SATURDAY AFTERNOON SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS SPREAD ACROSS CENTRAL AND NORTH
CENTRAL MONTANA AS WELL. AS HAS BEEN MENTIONED OVER THE LAST FEW
DAYS, I AM NOT EXPECTED ANY SEVERE WEATHER AS CAPE AND SHEAR
REMAIN RELATIVELY WEAK. MPJ

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.AVIATION... UPDATED 0000Z.

A RELATIVELY MORE MOIST/UNSTABLE AIRMASS HAS MOVED NORTH INTO SW MT
WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS
EVENING...MAINLY SOUTH OF KHLN TO KGTF. BRIEF MVFR CONDITIONS ARE
POSSIBLE UNDER THESE CELLS THIS EVENING WITH LOCAL TERRAIN
OBSCURATIONS. VFR CONDITIONS WILL PREVAIL OTHERWISE WITH SHOWERS AND
THUNDERSTORMS ENDING BY MIDNIGHT. EAST TO SOUTHEAST SURFACE WINDS
WILL CONTINUE THROUGH TOMORROW AND MAY BE LOCALLY GUSTY AT TIMES AT
THE KLWT AND KHVR TERMINALS. AREA OF MOISTURE/INSTABILITY SPREADS
FURTHER NORTH FRIDAY AFTERNOON WITH SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS POSSIBLE FURTHER NORTH INTO NORTH CENTRAL MT BY FRIDAY
EVENING. HOENISCH

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  43  70  46  67 /  10  20  30  40
CTB  37  69  41  68 /   0  10  10  20
HLN  45  72  48  67 /  30  30  30  60
BZN  39  69  42  64 /  30  40  30  50
WEY  32  61  34  58 /  40  50  60  60
DLN  41  66  44  64 /  50  40  30  50
HVR  38  73  43  73 /   0  10  30  20
LWT  41  69  45  64 /   0  40  40  40

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS




000
FXUS65 KTFX 220320
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
915 PM MDT THU MAY 21 2015

.UPDATE... LATEST RADAR IMAGERY SHOWS RAIN SHOWERS NEAR HELENA AND
PARTS OF BEAVERHEAD COUNTY CONTINUING TO SLOWLY DISSIPATE WHILE
SKIES ARE MOSTLY CLEAR ACROSS THE HILINE AND MOST OF THE CENTRAL MT
COUNTIES.  PRIMARY FORECAST ADJUSTMENT THIS EVENING WAS TO REDUCE
PRECIP CHANCES ACROSS JEFFERSON/BROADWATER/MADISON/GALLATIN COUNTIES
NOW THAT PRECIP HAS ENDED THERE.  PREDICTED OVERNIGHT TEMPERATURES
LOOK GOOD AT THIS TIME.
WARANAUSKAS

&&

.DISCUSSION...

TONIGHT THROUGH SATURDAY...RELATIVELY LIGHT UPPER LEVEL FLOW FROM
THE SOUTHEAST WILL CONTINUE OVERNIGHT BUT IS EXPECTED TO SHIFT
EAST-NORTHEAST AND INCREASE BY SATURDAY. SCATTERED TO NUMEROUS
SHOWERS AND A FEW THUNDERSTORMS CAN BE EXPECTED ACROSS SOUTHWEST
MONTANA THIS AFTERNOON AND EVENING BEFORE TAPERING OFF TO ISOLATED
SHOWERS OVERNIGHT. ISOLATED CONVECTION COULD REACH SOUTHERN PORTIONS
OF CENTRAL MONTANA THIS AFTERNOON AND EVENING AS WELL. HOWEVER,
FROM FRIDAY EVENING THROUGH SATURDAY AFTERNOON SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS SPREAD ACROSS CENTRAL AND NORTH
CENTRAL MONTANA AS WELL. AS HAS BEEN MENTIONED OVER THE LAST FEW
DAYS, I AM NOT EXPECTED ANY SEVERE WEATHER AS CAPE AND SHEAR
REMAIN RELATIVELY WEAK. MPJ

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.AVIATION... UPDATED 0000Z.

A RELATIVELY MORE MOIST/UNSTABLE AIRMASS HAS MOVED NORTH INTO SW MT
WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS
EVENING...MAINLY SOUTH OF KHLN TO KGTF. BRIEF MVFR CONDITIONS ARE
POSSIBLE UNDER THESE CELLS THIS EVENING WITH LOCAL TERRAIN
OBSCURATIONS. VFR CONDITIONS WILL PREVAIL OTHERWISE WITH SHOWERS AND
THUNDERSTORMS ENDING BY MIDNIGHT. EAST TO SOUTHEAST SURFACE WINDS
WILL CONTINUE THROUGH TOMORROW AND MAY BE LOCALLY GUSTY AT TIMES AT
THE KLWT AND KHVR TERMINALS. AREA OF MOISTURE/INSTABILITY SPREADS
FURTHER NORTH FRIDAY AFTERNOON WITH SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS POSSIBLE FURTHER NORTH INTO NORTH CENTRAL MT BY FRIDAY
EVENING. HOENISCH

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  43  70  46  67 /  10  20  30  40
CTB  37  69  41  68 /   0  10  10  20
HLN  45  72  48  67 /  30  30  30  60
BZN  39  69  42  64 /  30  40  30  50
WEY  32  61  34  58 /  40  50  60  60
DLN  41  66  44  64 /  50  40  30  50
HVR  38  73  43  73 /   0  10  30  20
LWT  41  69  45  64 /   0  40  40  40

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KGGW 220308 AAA
AFDGGW

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE GLASGOW MT
908 PM MDT THU MAY 21 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SATURDAY...

VISUAL OBSERVATION AND SATELLITE IMAGERY REVEALS ANOTHER CLOUD-
FREE EVENING FOR NORTHEAST MONTANA. HOWEVER A LARGER SCALE VIEW
SHOWS A STORM SYSTEM CENTERED OVER COLORADO HEADING NORTH AND
SPREADING CLOUD COVER NORTH. MID TO HIGH CLOUD COVER SHOULD BEGIN
TO MOVE INTO NORTHEAST MONTANA AFTER MIDNIGHT. THE BRISK SOUTHEAST
WINDS OF TODAY ARE BEGINNING TO DIMINISH CLOSE TO SUNSET. GRIDS
HANDLE THIS WELL...SO NO PLANNED UPDATE. SCT

PREVIOUS DISCUSSION...
SYNOPTIC SET UP... A CLOSED LOW SETS OVER THE QUEBEC/ONTARIO
BORDER WITH A LARGE TROUGH SURROUNDING IT AND EXTENDING ITS
INFLUENCE INTO THE EASTERN TWO THIRDS OF THE CONUS. A NARROW HIGH
AMPLITUDE RIDGE HAS DEVELOPED OVER THE WESTERN THIRD OF THE US AND
CANADA. NORTHEAST MONTANA STANDS BETWEEN THESE TWO FEATURES UNDER
NORTHERN TO NORTHWESTERN FLOW ALOFT. FARTHER WEST ANOTHER MORE
NARROW TROUGH EXTENDS FROM OFF THE COASTS OF BRITISH COLUMBIA TO
SOUTHERN CALIFORNIA.

TONIGHT... DRY NORTHERN FLOW ALOFT AND SURFACE HIGH PRESSURE ACROSS
THE REGION WILL ACT TO KEEP NORTHEASTERN MONTANA DRY AND CLEAR.

FRIDAY THROUGH FRIDAY NIGHT... WITH ATMOSPHERE SLOWLY MODIFYING
WARMER AT THE SURFACE AND COOLER MID LEVEL AIR ENTER IN THE REGION
FROM THE SOUTHEAST SOME INSTABILITY IS EXPECTED TO DEVELOPED
FRIDAY AFTERNOON. AREAS OF OROGRAPHIC LIFT SUCH AS THE CENTRAL
MONTANA MOUNTAINS ARE WHERE THIS INSTABILITY SHOULD INITIALIZE.
SOME SPILL OVER INT THE AFTERNOON AND EVENINGS HOURS IS POSSIBLE
FOR PETROLEUM... PHILLIPS... AND WESTERN GARFIELD COUNTY.

STRONG SURFACE WINDS WILL ALSO ALLOW FOR A LAKE WIND ADVISORY TO
BE IN AFFECT DURING THE AFTERNOON HOURS.

SATURDAY... A CHANCE FOR MOUNTAIN INSTABILITY STILL EXISTS BUT
LESSENS. FOCUS SHIFTS TO THE SOUTHEASTERN CWA WITH A COLD AIR
POCKET DEVELOPING OVER THE DAKOTAS AND EASTERN MT. THIS WILL
ALLOW A LIFT ZONE TO FORM AND SHOWERS TO SPILL INTO THE YELLOWSTONE
VALLEY THAT AFTERNOON AND EVENING. GAH


.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
12Z MODELS REMAINED INCONSISTENT WITH PRECIP PLACEMENT LATER THIS
WEEKEND. THIS TIME THE GFS DRAGGED PRECIP INTO THE CWA FROM THE
SOUTHEAST AND WAS SLOWER TO PUSH IT OUT OF HERE EARLY NEXT WEEK.
MAINLY TRIMMED POPS AS THE PRECIP AREA HAS TRENDED EAST A BIT.
INSTABILITY WITH THE NEIGHBORING UPPER LOW WILL LEAD TO SLIGHT
CHANCE OF SHOWERS. TFJ

PREVIOUS DISCUSSION...
SATURDAY NIGHT AND SUNDAY FEATURES A BROAD UPPER TROUGH OVER THE
WEST AND AN UPPER RIDGE TO EAST OF NORTHEAST MONTANA. THE TROUGH
WILL LIFT NORTH INTO MONTANA AND NORTH DAKOTA BY MONDAY. THEN...THE
FLOW PATTERN ALOFT OVER MONTANA WILL BE WEAK...VARIABLE AND UN-
FOCUSED MONDAY AND TUESDAY. THE SOUTHEAST HALF OF THE FORECAST
AREA HAS A BETTER CHANCE OF SEEING SHOWERS MAYBE THUNDERSTORMS AT
TIMES BETWEEN SATURDAY NIGHT AND MONDAY WHERE THE DEEPER MOISTURE
IS EXPECTED.

MODEL DIFFERENCES SHOW UP TUESDAY AND BEYOND AS GFS HAS A NW FLOW
ALOFT WITH A BACK DOOR COLD FRONT ON WEDNESDAY. ECMWF HAS AN UPPER
TROUGH OVER THE PACIFIC NW ON TUESDAY THAT EVENTUALLY MOVES EAST
ACROSS MONTANA WEDNESDAY AND THURSDAY. WILL MAINTAIN A
CHANCE/SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR NOW.
FORRESTER

&&

.AVIATION...
VFR.

HIGH PRESSURE OVER THE DAKOTA/S WILL CONTINUE CLEAR SKIES AND EAST
TO SOUTHEAST WIND FOR THE REGION. MAIN IMPACT WILL BE THE EAST TO
SOUTHEAST WIND LIGHTER OVERNIGHT AND UP TO 10 TO 20 KTS DURING THE
DAY ON FRIDAY.         PROTON

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM 11 AM TO 8 PM MDT FRIDAY FOR FORT PECK
LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN
VALLEY...GARFIELD...MCCONE...PETROLEUM.

&&

$$

WEATHER.GOV/GLASGOW





000
FXUS65 KGGW 220308 AAA
AFDGGW

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE GLASGOW MT
908 PM MDT THU MAY 21 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SATURDAY...

VISUAL OBSERVATION AND SATELLITE IMAGERY REVEALS ANOTHER CLOUD-
FREE EVENING FOR NORTHEAST MONTANA. HOWEVER A LARGER SCALE VIEW
SHOWS A STORM SYSTEM CENTERED OVER COLORADO HEADING NORTH AND
SPREADING CLOUD COVER NORTH. MID TO HIGH CLOUD COVER SHOULD BEGIN
TO MOVE INTO NORTHEAST MONTANA AFTER MIDNIGHT. THE BRISK SOUTHEAST
WINDS OF TODAY ARE BEGINNING TO DIMINISH CLOSE TO SUNSET. GRIDS
HANDLE THIS WELL...SO NO PLANNED UPDATE. SCT

PREVIOUS DISCUSSION...
SYNOPTIC SET UP... A CLOSED LOW SETS OVER THE QUEBEC/ONTARIO
BORDER WITH A LARGE TROUGH SURROUNDING IT AND EXTENDING ITS
INFLUENCE INTO THE EASTERN TWO THIRDS OF THE CONUS. A NARROW HIGH
AMPLITUDE RIDGE HAS DEVELOPED OVER THE WESTERN THIRD OF THE US AND
CANADA. NORTHEAST MONTANA STANDS BETWEEN THESE TWO FEATURES UNDER
NORTHERN TO NORTHWESTERN FLOW ALOFT. FARTHER WEST ANOTHER MORE
NARROW TROUGH EXTENDS FROM OFF THE COASTS OF BRITISH COLUMBIA TO
SOUTHERN CALIFORNIA.

TONIGHT... DRY NORTHERN FLOW ALOFT AND SURFACE HIGH PRESSURE ACROSS
THE REGION WILL ACT TO KEEP NORTHEASTERN MONTANA DRY AND CLEAR.

FRIDAY THROUGH FRIDAY NIGHT... WITH ATMOSPHERE SLOWLY MODIFYING
WARMER AT THE SURFACE AND COOLER MID LEVEL AIR ENTER IN THE REGION
FROM THE SOUTHEAST SOME INSTABILITY IS EXPECTED TO DEVELOPED
FRIDAY AFTERNOON. AREAS OF OROGRAPHIC LIFT SUCH AS THE CENTRAL
MONTANA MOUNTAINS ARE WHERE THIS INSTABILITY SHOULD INITIALIZE.
SOME SPILL OVER INT THE AFTERNOON AND EVENINGS HOURS IS POSSIBLE
FOR PETROLEUM... PHILLIPS... AND WESTERN GARFIELD COUNTY.

STRONG SURFACE WINDS WILL ALSO ALLOW FOR A LAKE WIND ADVISORY TO
BE IN AFFECT DURING THE AFTERNOON HOURS.

SATURDAY... A CHANCE FOR MOUNTAIN INSTABILITY STILL EXISTS BUT
LESSENS. FOCUS SHIFTS TO THE SOUTHEASTERN CWA WITH A COLD AIR
POCKET DEVELOPING OVER THE DAKOTAS AND EASTERN MT. THIS WILL
ALLOW A LIFT ZONE TO FORM AND SHOWERS TO SPILL INTO THE YELLOWSTONE
VALLEY THAT AFTERNOON AND EVENING. GAH


.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
12Z MODELS REMAINED INCONSISTENT WITH PRECIP PLACEMENT LATER THIS
WEEKEND. THIS TIME THE GFS DRAGGED PRECIP INTO THE CWA FROM THE
SOUTHEAST AND WAS SLOWER TO PUSH IT OUT OF HERE EARLY NEXT WEEK.
MAINLY TRIMMED POPS AS THE PRECIP AREA HAS TRENDED EAST A BIT.
INSTABILITY WITH THE NEIGHBORING UPPER LOW WILL LEAD TO SLIGHT
CHANCE OF SHOWERS. TFJ

PREVIOUS DISCUSSION...
SATURDAY NIGHT AND SUNDAY FEATURES A BROAD UPPER TROUGH OVER THE
WEST AND AN UPPER RIDGE TO EAST OF NORTHEAST MONTANA. THE TROUGH
WILL LIFT NORTH INTO MONTANA AND NORTH DAKOTA BY MONDAY. THEN...THE
FLOW PATTERN ALOFT OVER MONTANA WILL BE WEAK...VARIABLE AND UN-
FOCUSED MONDAY AND TUESDAY. THE SOUTHEAST HALF OF THE FORECAST
AREA HAS A BETTER CHANCE OF SEEING SHOWERS MAYBE THUNDERSTORMS AT
TIMES BETWEEN SATURDAY NIGHT AND MONDAY WHERE THE DEEPER MOISTURE
IS EXPECTED.

MODEL DIFFERENCES SHOW UP TUESDAY AND BEYOND AS GFS HAS A NW FLOW
ALOFT WITH A BACK DOOR COLD FRONT ON WEDNESDAY. ECMWF HAS AN UPPER
TROUGH OVER THE PACIFIC NW ON TUESDAY THAT EVENTUALLY MOVES EAST
ACROSS MONTANA WEDNESDAY AND THURSDAY. WILL MAINTAIN A
CHANCE/SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR NOW.
FORRESTER

&&

.AVIATION...
VFR.

HIGH PRESSURE OVER THE DAKOTA/S WILL CONTINUE CLEAR SKIES AND EAST
TO SOUTHEAST WIND FOR THE REGION. MAIN IMPACT WILL BE THE EAST TO
SOUTHEAST WIND LIGHTER OVERNIGHT AND UP TO 10 TO 20 KTS DURING THE
DAY ON FRIDAY.         PROTON

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM 11 AM TO 8 PM MDT FRIDAY FOR FORT PECK
LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN
VALLEY...GARFIELD...MCCONE...PETROLEUM.

&&

$$

WEATHER.GOV/GLASGOW






000
FXUS65 KGGW 220308 AAA
AFDGGW

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE GLASGOW MT
908 PM MDT THU MAY 21 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SATURDAY...

VISUAL OBSERVATION AND SATELLITE IMAGERY REVEALS ANOTHER CLOUD-
FREE EVENING FOR NORTHEAST MONTANA. HOWEVER A LARGER SCALE VIEW
SHOWS A STORM SYSTEM CENTERED OVER COLORADO HEADING NORTH AND
SPREADING CLOUD COVER NORTH. MID TO HIGH CLOUD COVER SHOULD BEGIN
TO MOVE INTO NORTHEAST MONTANA AFTER MIDNIGHT. THE BRISK SOUTHEAST
WINDS OF TODAY ARE BEGINNING TO DIMINISH CLOSE TO SUNSET. GRIDS
HANDLE THIS WELL...SO NO PLANNED UPDATE. SCT

PREVIOUS DISCUSSION...
SYNOPTIC SET UP... A CLOSED LOW SETS OVER THE QUEBEC/ONTARIO
BORDER WITH A LARGE TROUGH SURROUNDING IT AND EXTENDING ITS
INFLUENCE INTO THE EASTERN TWO THIRDS OF THE CONUS. A NARROW HIGH
AMPLITUDE RIDGE HAS DEVELOPED OVER THE WESTERN THIRD OF THE US AND
CANADA. NORTHEAST MONTANA STANDS BETWEEN THESE TWO FEATURES UNDER
NORTHERN TO NORTHWESTERN FLOW ALOFT. FARTHER WEST ANOTHER MORE
NARROW TROUGH EXTENDS FROM OFF THE COASTS OF BRITISH COLUMBIA TO
SOUTHERN CALIFORNIA.

TONIGHT... DRY NORTHERN FLOW ALOFT AND SURFACE HIGH PRESSURE ACROSS
THE REGION WILL ACT TO KEEP NORTHEASTERN MONTANA DRY AND CLEAR.

FRIDAY THROUGH FRIDAY NIGHT... WITH ATMOSPHERE SLOWLY MODIFYING
WARMER AT THE SURFACE AND COOLER MID LEVEL AIR ENTER IN THE REGION
FROM THE SOUTHEAST SOME INSTABILITY IS EXPECTED TO DEVELOPED
FRIDAY AFTERNOON. AREAS OF OROGRAPHIC LIFT SUCH AS THE CENTRAL
MONTANA MOUNTAINS ARE WHERE THIS INSTABILITY SHOULD INITIALIZE.
SOME SPILL OVER INT THE AFTERNOON AND EVENINGS HOURS IS POSSIBLE
FOR PETROLEUM... PHILLIPS... AND WESTERN GARFIELD COUNTY.

STRONG SURFACE WINDS WILL ALSO ALLOW FOR A LAKE WIND ADVISORY TO
BE IN AFFECT DURING THE AFTERNOON HOURS.

SATURDAY... A CHANCE FOR MOUNTAIN INSTABILITY STILL EXISTS BUT
LESSENS. FOCUS SHIFTS TO THE SOUTHEASTERN CWA WITH A COLD AIR
POCKET DEVELOPING OVER THE DAKOTAS AND EASTERN MT. THIS WILL
ALLOW A LIFT ZONE TO FORM AND SHOWERS TO SPILL INTO THE YELLOWSTONE
VALLEY THAT AFTERNOON AND EVENING. GAH


.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
12Z MODELS REMAINED INCONSISTENT WITH PRECIP PLACEMENT LATER THIS
WEEKEND. THIS TIME THE GFS DRAGGED PRECIP INTO THE CWA FROM THE
SOUTHEAST AND WAS SLOWER TO PUSH IT OUT OF HERE EARLY NEXT WEEK.
MAINLY TRIMMED POPS AS THE PRECIP AREA HAS TRENDED EAST A BIT.
INSTABILITY WITH THE NEIGHBORING UPPER LOW WILL LEAD TO SLIGHT
CHANCE OF SHOWERS. TFJ

PREVIOUS DISCUSSION...
SATURDAY NIGHT AND SUNDAY FEATURES A BROAD UPPER TROUGH OVER THE
WEST AND AN UPPER RIDGE TO EAST OF NORTHEAST MONTANA. THE TROUGH
WILL LIFT NORTH INTO MONTANA AND NORTH DAKOTA BY MONDAY. THEN...THE
FLOW PATTERN ALOFT OVER MONTANA WILL BE WEAK...VARIABLE AND UN-
FOCUSED MONDAY AND TUESDAY. THE SOUTHEAST HALF OF THE FORECAST
AREA HAS A BETTER CHANCE OF SEEING SHOWERS MAYBE THUNDERSTORMS AT
TIMES BETWEEN SATURDAY NIGHT AND MONDAY WHERE THE DEEPER MOISTURE
IS EXPECTED.

MODEL DIFFERENCES SHOW UP TUESDAY AND BEYOND AS GFS HAS A NW FLOW
ALOFT WITH A BACK DOOR COLD FRONT ON WEDNESDAY. ECMWF HAS AN UPPER
TROUGH OVER THE PACIFIC NW ON TUESDAY THAT EVENTUALLY MOVES EAST
ACROSS MONTANA WEDNESDAY AND THURSDAY. WILL MAINTAIN A
CHANCE/SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR NOW.
FORRESTER

&&

.AVIATION...
VFR.

HIGH PRESSURE OVER THE DAKOTA/S WILL CONTINUE CLEAR SKIES AND EAST
TO SOUTHEAST WIND FOR THE REGION. MAIN IMPACT WILL BE THE EAST TO
SOUTHEAST WIND LIGHTER OVERNIGHT AND UP TO 10 TO 20 KTS DURING THE
DAY ON FRIDAY.         PROTON

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM 11 AM TO 8 PM MDT FRIDAY FOR FORT PECK
LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN
VALLEY...GARFIELD...MCCONE...PETROLEUM.

&&

$$

WEATHER.GOV/GLASGOW





000
FXUS65 KGGW 220308 AAA
AFDGGW

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE GLASGOW MT
908 PM MDT THU MAY 21 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SATURDAY...

VISUAL OBSERVATION AND SATELLITE IMAGERY REVEALS ANOTHER CLOUD-
FREE EVENING FOR NORTHEAST MONTANA. HOWEVER A LARGER SCALE VIEW
SHOWS A STORM SYSTEM CENTERED OVER COLORADO HEADING NORTH AND
SPREADING CLOUD COVER NORTH. MID TO HIGH CLOUD COVER SHOULD BEGIN
TO MOVE INTO NORTHEAST MONTANA AFTER MIDNIGHT. THE BRISK SOUTHEAST
WINDS OF TODAY ARE BEGINNING TO DIMINISH CLOSE TO SUNSET. GRIDS
HANDLE THIS WELL...SO NO PLANNED UPDATE. SCT

PREVIOUS DISCUSSION...
SYNOPTIC SET UP... A CLOSED LOW SETS OVER THE QUEBEC/ONTARIO
BORDER WITH A LARGE TROUGH SURROUNDING IT AND EXTENDING ITS
INFLUENCE INTO THE EASTERN TWO THIRDS OF THE CONUS. A NARROW HIGH
AMPLITUDE RIDGE HAS DEVELOPED OVER THE WESTERN THIRD OF THE US AND
CANADA. NORTHEAST MONTANA STANDS BETWEEN THESE TWO FEATURES UNDER
NORTHERN TO NORTHWESTERN FLOW ALOFT. FARTHER WEST ANOTHER MORE
NARROW TROUGH EXTENDS FROM OFF THE COASTS OF BRITISH COLUMBIA TO
SOUTHERN CALIFORNIA.

TONIGHT... DRY NORTHERN FLOW ALOFT AND SURFACE HIGH PRESSURE ACROSS
THE REGION WILL ACT TO KEEP NORTHEASTERN MONTANA DRY AND CLEAR.

FRIDAY THROUGH FRIDAY NIGHT... WITH ATMOSPHERE SLOWLY MODIFYING
WARMER AT THE SURFACE AND COOLER MID LEVEL AIR ENTER IN THE REGION
FROM THE SOUTHEAST SOME INSTABILITY IS EXPECTED TO DEVELOPED
FRIDAY AFTERNOON. AREAS OF OROGRAPHIC LIFT SUCH AS THE CENTRAL
MONTANA MOUNTAINS ARE WHERE THIS INSTABILITY SHOULD INITIALIZE.
SOME SPILL OVER INT THE AFTERNOON AND EVENINGS HOURS IS POSSIBLE
FOR PETROLEUM... PHILLIPS... AND WESTERN GARFIELD COUNTY.

STRONG SURFACE WINDS WILL ALSO ALLOW FOR A LAKE WIND ADVISORY TO
BE IN AFFECT DURING THE AFTERNOON HOURS.

SATURDAY... A CHANCE FOR MOUNTAIN INSTABILITY STILL EXISTS BUT
LESSENS. FOCUS SHIFTS TO THE SOUTHEASTERN CWA WITH A COLD AIR
POCKET DEVELOPING OVER THE DAKOTAS AND EASTERN MT. THIS WILL
ALLOW A LIFT ZONE TO FORM AND SHOWERS TO SPILL INTO THE YELLOWSTONE
VALLEY THAT AFTERNOON AND EVENING. GAH


.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
12Z MODELS REMAINED INCONSISTENT WITH PRECIP PLACEMENT LATER THIS
WEEKEND. THIS TIME THE GFS DRAGGED PRECIP INTO THE CWA FROM THE
SOUTHEAST AND WAS SLOWER TO PUSH IT OUT OF HERE EARLY NEXT WEEK.
MAINLY TRIMMED POPS AS THE PRECIP AREA HAS TRENDED EAST A BIT.
INSTABILITY WITH THE NEIGHBORING UPPER LOW WILL LEAD TO SLIGHT
CHANCE OF SHOWERS. TFJ

PREVIOUS DISCUSSION...
SATURDAY NIGHT AND SUNDAY FEATURES A BROAD UPPER TROUGH OVER THE
WEST AND AN UPPER RIDGE TO EAST OF NORTHEAST MONTANA. THE TROUGH
WILL LIFT NORTH INTO MONTANA AND NORTH DAKOTA BY MONDAY. THEN...THE
FLOW PATTERN ALOFT OVER MONTANA WILL BE WEAK...VARIABLE AND UN-
FOCUSED MONDAY AND TUESDAY. THE SOUTHEAST HALF OF THE FORECAST
AREA HAS A BETTER CHANCE OF SEEING SHOWERS MAYBE THUNDERSTORMS AT
TIMES BETWEEN SATURDAY NIGHT AND MONDAY WHERE THE DEEPER MOISTURE
IS EXPECTED.

MODEL DIFFERENCES SHOW UP TUESDAY AND BEYOND AS GFS HAS A NW FLOW
ALOFT WITH A BACK DOOR COLD FRONT ON WEDNESDAY. ECMWF HAS AN UPPER
TROUGH OVER THE PACIFIC NW ON TUESDAY THAT EVENTUALLY MOVES EAST
ACROSS MONTANA WEDNESDAY AND THURSDAY. WILL MAINTAIN A
CHANCE/SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR NOW.
FORRESTER

&&

.AVIATION...
VFR.

HIGH PRESSURE OVER THE DAKOTA/S WILL CONTINUE CLEAR SKIES AND EAST
TO SOUTHEAST WIND FOR THE REGION. MAIN IMPACT WILL BE THE EAST TO
SOUTHEAST WIND LIGHTER OVERNIGHT AND UP TO 10 TO 20 KTS DURING THE
DAY ON FRIDAY.         PROTON

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM 11 AM TO 8 PM MDT FRIDAY FOR FORT PECK
LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN
VALLEY...GARFIELD...MCCONE...PETROLEUM.

&&

$$

WEATHER.GOV/GLASGOW






000
FXUS65 KBYZ 220254
AFDBYZ

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
854 PM MDT THU MAY 21 2015

.UPDATE...
UPDATED FORECAST TO REMOVE THE EARLY EVENING POPS THAT INCLUDED A
CHANCE OF THUNDERSTORMS OVER AND NEAR THE MOUNTAINS. AIRMASS WAS
STABILIZING BASED ON MESOANALYSIS SO WOULD NOT EXPECT ANY MORE
THUNDER OVERNIGHT. WEBCAMS AND SURFACE OBSERVATIONS SHOWED THAT
SHOWERS WERE CONFINED MAINLY TO THE MOUNTAINS THIS EVENING. KLVM
HAS BEEN REPORTING RAIN OVER THE LAST FEW HOURS...BUT ONLY LIGHT
RAIN WAS REPORTED RECENTLY. MOISTURE WAS ADVECTING N THIS EVENING
PER SATELLITE IMAGERY AHEAD OF A STRONG WAVE OVER AZ/NM. MODELS
SHOWED THIS WAVE MOVING N AND WEAKENING OVERNIGHT...SUPPORTING
LIGHT QPF OVER THE SOUTHERN MOUNTAINS. POPS REFLECTED LATEST
OBSERVED AND MODEL TRENDS. RAISED DEWPOINTS W OF KBIL PER LATEST
GUIDANCE AND DUE TO THE SHOWER ACTIVITY. EXPECT HIGH HUMIDITIES
OVER THE W OVERNIGHT. THE HUMIDITY COMBINED WITH RECENT RAINFALL
WILL SUPPORT PATCHY FOG. ADJUSTED SKY COVER THROUGH 06Z TO FIT
LATEST SATELLITE TRENDS.

WEAK UPPER FLOW WITH SOME LIFT FROM SHORTWAVES WILL BE OVER THE
AREA ON FRI ALONG WITH SE FLOW CONTINUING TO PUMP MOISTURE INTO
THE REGION. SPC PLUMES SHOWED HIGHER CAPE VALUES FRI AFTERNOON
BUT WEAK SHEAR. WILL HAVE ANOTHER ROUND OF MOUNTAIN SHOWERS AND
THUNDERSTORMS WITH SOME ACTIVITY SPREADING OUT ONTO THE PLAINS.
ARTHUR

&&

.SHORT TERM...VALID FOR FRI AND SAT...

SOMEWHAT BENIGN FLOW OVER THE REGION TODAY AS UPPER LOW OFF
CALIFORNIA COAST TRACKS INTO SOUTHERN CALIFORNIA BY EVENING.
WE HAVE SOME MOISTURE THAT HAS ADVECTED INTO WESTERN MONTANA
WHILE THE EAST REMAINS GENERALLY DRY. SO ISOLATED TO SCATTERED
SHOWERS AND MAYBE SOME THUNDER IS EXPECTED THROUGH THE
EVENING...WITH A BIT LINGERING OVERNIGHT. FLOW IS WEAK SO WE DONT
EXPECT THOSE SHOWERS TO MAKE MUCH HEADWAY INTO THE PLAINS.
SOUTHERLY FLOW AND MAYBE AN INCREASE IN HIGH CLOUDS TONIGHT SO I
DO NOT THINK WE WILL GET QUITE AS CHILLY AS WE HAVE BEEN RECENTLY.

FRIDAY/FRIDAY NIGHT...UPPER LOW TRACKS INTO THE DESERT SOUTHWEST
WITH A PIECE OF ENERGY EJECTING OUT AHEAD OF IT IN THE SOUTH TO
NORTH FLOW ALOFT. THIS WILL PUSH INTO WYOMING BY AFTERNOON AND
SPREAD SOME SHOWERS AND PERHAPS SOME THUNDERSTORMS INTO OUR
FORECAST AREA. I LEFT THE HIGHEST POPS OVER THE HIGH COUNTRY TO
THE WEST...REDUCED THE PPS A BIT FOR THE NORTH CENTRAL ZONES
NORTH OF I-94 BASED ON CURRENT PROGGS TRACKING THIS SHORT WAVE
ENERGY. LOOK FOR TEMPS EQUAL TO OR A LITTLE HIGHER THAN TODAYS ON
FRIDAY AS WARMER AIR ADVECTS NORTHWARD THANKS TO THE SOUTHERLY
FLOW.

THAT UPPER LOW PUSHES INTO THE CENTRAL ROCKIES FOR THE START OF
THE WEEKEND. ITS INFLUENCE WILL CONTINUE TO PRODUCE INCREASING
PRECIPITABLE WATERS ACROSS OUR FORECAST AREA. THUS THE WIDESPREAD
SHOWERS AND SOME THUNDERSTORMS WE ARE ADVERTISING FOR SATURDAY AND
SATURDAY NIGHT LOOKS ON TRACK. WEAK WIND FIELDS SHOULD NOT SUPPORT
ANY ORGANIZED SEVERE THREAT...THOUGH AS LAST WEEK INDICATED...AN
ISOLATED STORM WITH LARGER HAIL CANNOT BE COMPLETELY RULED OUT. BT


.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...

OVERALL EXTENDED FORECAST APPEARS IN GOOD SHAPE...WITH BROAD
UPPER LEVEL TROF IN CONTROL OVER THE REGION THROUGHOUT THE
MAJORITY OF THE PERIOD. ONLY SMALL ADJUSTMENTS WERE MADE TO CLEAN
UP BORDERS AND CONTINUE TO SLOW TREND TEMPERATURES UPWARD TOWARD
NORMAL THROUGH THE PERIOD.

THE REGION CONTINUES TO BE IMPACTED BY NORTHERN PORTION OF A
STRETCHED OUT UPPER LOW INTO NORTHEAST WYOMING AS IT MOVES INTO
THE DAKOTAS ON SUNDAY. PERSISTENT EAST TO SOUTHEAST SURFACE FLOW
WILL SUPPORT PWATS INTO THE ONE INCH RANGE IN SOUTHEAST MONTANA.
DEEP MOISTURE AVAILABILITY SHOULD ALLOW FOR A GOOD CHANCE FOR
SHOWERS...ESPECIALLY EAST OF BILLINGS. ATMOSPHERE DOES NOT APPEAR
VERY UNSTABLE...SO EXPECT LESS CHANCE OF THUNDER. IMPACTS TO THE
EAST WILL SLOWLY DECREASE THOUGHT MONDAY.

THERE IS SOME INDICATION OF A SHORT PERIOD OF SHORTWAVE RIDGING
ACROSS THE REGION MONDAY NIGHT...AHEAD OF THE NEXT SYSTEM. THIS
WILL BRING A BREAK IN PRECIP OVERNIGHT...BUT TIMING OF THE NEXT
SYSTEM SHOULD KEEP SOME CLOUD COVER IN PLACE AS MOISTURE CONTINUES
TO FLOW INTO THE WESTERN MOUNTAINS.

THE NEXT UPPER LEVEL LOW PRESSURE SYSTEM WILL DROP INTO THE REGION
FROM BRITISH COLUMBIA ON TUESDAY OR WEDNESDAY DEPENDING ON WHICH
MODEL YOU FAVOR. THE EC IS CURRENTLY MUCH FASTER BRINGING THE
SYSTEM INTO THE REGION...AND KEEPING IT OVER THE REGION UNTIL
THURSDAY MORNING. THE GFS HOLD THE LOW TO THE WEST UNTIL
WEDNESDAY...BUT KEEPS IT OVER THE REGION THROUGH THE END OF THE
PERIOD. HAVE GOING POPS INTACT...AS GFS HAS MADE SIGNIFICANT
CHANGE THIS RUN...BUT WILL BE WORTH FURTHER ATTENTION ON LATER
SHIFT. AAG

&&

.AVIATION...

ISOLATED SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO LATE EVENING
ALONG AND NEAR AREA MOUNTAINS. LOCAL MVFR TO IFR CONDITIONS CAN
BE EXPECTED NEAR THIS ACTIVITY. THERE IS A VERY SLIGHT CHANCE FOR
PATCHY LOW LYING FOG OR STRATUS DEVELOPMENT AROUND SUNRISE JUST
ABOUT EVERYWHERE. WILL MONITOR THIS POTENTIAL OVERNIGHT. OTHERWISE
VFR CONDITIONS ARE EXPECTED OVERNIGHT. CHAMBERS
&&

.PRELIMINARY POINT TEMP/POPS...

    FRI     SAT     SUN     MON     TUE     WED     THU
-----------------------------------------------------------
BIL 044/071 046/064 046/063 045/070 048/070 048/072 047/068
    03/T    23/T    23/T    32/T    23/T    33/T    33/T
LVM 040/067 044/060 042/061 039/066 043/066 044/067 041/066
    24/T    35/T    43/T    33/T    34/T    44/T    43/T
HDN 044/073 045/066 046/064 045/072 047/073 048/075 047/071
    03/T    23/T    33/T    32/T    23/T    33/T    33/T
MLS 045/073 046/065 046/064 047/069 046/072 049/073 048/069
    01/B    12/T    34/T    43/T    22/T    23/T    33/T
4BQ 044/068 043/062 046/060 045/068 045/072 048/073 048/069
    02/T    25/T    36/T    43/T    23/T    33/T    34/T
BHK 041/069 042/060 044/061 044/065 043/069 046/069 045/066
    01/N    25/T    46/T    55/T    33/T    33/T    33/T
SHR 041/064 041/060 043/058 041/068 043/069 044/070 045/067
    13/T    25/T    44/T    32/T    24/T    43/T    33/T

&&

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

&&

$$
WEATHER.GOV/BILLINGS



000
FXUS65 KBYZ 220254
AFDBYZ

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
854 PM MDT THU MAY 21 2015

.UPDATE...
UPDATED FORECAST TO REMOVE THE EARLY EVENING POPS THAT INCLUDED A
CHANCE OF THUNDERSTORMS OVER AND NEAR THE MOUNTAINS. AIRMASS WAS
STABILIZING BASED ON MESOANALYSIS SO WOULD NOT EXPECT ANY MORE
THUNDER OVERNIGHT. WEBCAMS AND SURFACE OBSERVATIONS SHOWED THAT
SHOWERS WERE CONFINED MAINLY TO THE MOUNTAINS THIS EVENING. KLVM
HAS BEEN REPORTING RAIN OVER THE LAST FEW HOURS...BUT ONLY LIGHT
RAIN WAS REPORTED RECENTLY. MOISTURE WAS ADVECTING N THIS EVENING
PER SATELLITE IMAGERY AHEAD OF A STRONG WAVE OVER AZ/NM. MODELS
SHOWED THIS WAVE MOVING N AND WEAKENING OVERNIGHT...SUPPORTING
LIGHT QPF OVER THE SOUTHERN MOUNTAINS. POPS REFLECTED LATEST
OBSERVED AND MODEL TRENDS. RAISED DEWPOINTS W OF KBIL PER LATEST
GUIDANCE AND DUE TO THE SHOWER ACTIVITY. EXPECT HIGH HUMIDITIES
OVER THE W OVERNIGHT. THE HUMIDITY COMBINED WITH RECENT RAINFALL
WILL SUPPORT PATCHY FOG. ADJUSTED SKY COVER THROUGH 06Z TO FIT
LATEST SATELLITE TRENDS.

WEAK UPPER FLOW WITH SOME LIFT FROM SHORTWAVES WILL BE OVER THE
AREA ON FRI ALONG WITH SE FLOW CONTINUING TO PUMP MOISTURE INTO
THE REGION. SPC PLUMES SHOWED HIGHER CAPE VALUES FRI AFTERNOON
BUT WEAK SHEAR. WILL HAVE ANOTHER ROUND OF MOUNTAIN SHOWERS AND
THUNDERSTORMS WITH SOME ACTIVITY SPREADING OUT ONTO THE PLAINS.
ARTHUR

&&

.SHORT TERM...VALID FOR FRI AND SAT...

SOMEWHAT BENIGN FLOW OVER THE REGION TODAY AS UPPER LOW OFF
CALIFORNIA COAST TRACKS INTO SOUTHERN CALIFORNIA BY EVENING.
WE HAVE SOME MOISTURE THAT HAS ADVECTED INTO WESTERN MONTANA
WHILE THE EAST REMAINS GENERALLY DRY. SO ISOLATED TO SCATTERED
SHOWERS AND MAYBE SOME THUNDER IS EXPECTED THROUGH THE
EVENING...WITH A BIT LINGERING OVERNIGHT. FLOW IS WEAK SO WE DONT
EXPECT THOSE SHOWERS TO MAKE MUCH HEADWAY INTO THE PLAINS.
SOUTHERLY FLOW AND MAYBE AN INCREASE IN HIGH CLOUDS TONIGHT SO I
DO NOT THINK WE WILL GET QUITE AS CHILLY AS WE HAVE BEEN RECENTLY.

FRIDAY/FRIDAY NIGHT...UPPER LOW TRACKS INTO THE DESERT SOUTHWEST
WITH A PIECE OF ENERGY EJECTING OUT AHEAD OF IT IN THE SOUTH TO
NORTH FLOW ALOFT. THIS WILL PUSH INTO WYOMING BY AFTERNOON AND
SPREAD SOME SHOWERS AND PERHAPS SOME THUNDERSTORMS INTO OUR
FORECAST AREA. I LEFT THE HIGHEST POPS OVER THE HIGH COUNTRY TO
THE WEST...REDUCED THE PPS A BIT FOR THE NORTH CENTRAL ZONES
NORTH OF I-94 BASED ON CURRENT PROGGS TRACKING THIS SHORT WAVE
ENERGY. LOOK FOR TEMPS EQUAL TO OR A LITTLE HIGHER THAN TODAYS ON
FRIDAY AS WARMER AIR ADVECTS NORTHWARD THANKS TO THE SOUTHERLY
FLOW.

THAT UPPER LOW PUSHES INTO THE CENTRAL ROCKIES FOR THE START OF
THE WEEKEND. ITS INFLUENCE WILL CONTINUE TO PRODUCE INCREASING
PRECIPITABLE WATERS ACROSS OUR FORECAST AREA. THUS THE WIDESPREAD
SHOWERS AND SOME THUNDERSTORMS WE ARE ADVERTISING FOR SATURDAY AND
SATURDAY NIGHT LOOKS ON TRACK. WEAK WIND FIELDS SHOULD NOT SUPPORT
ANY ORGANIZED SEVERE THREAT...THOUGH AS LAST WEEK INDICATED...AN
ISOLATED STORM WITH LARGER HAIL CANNOT BE COMPLETELY RULED OUT. BT


.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...

OVERALL EXTENDED FORECAST APPEARS IN GOOD SHAPE...WITH BROAD
UPPER LEVEL TROF IN CONTROL OVER THE REGION THROUGHOUT THE
MAJORITY OF THE PERIOD. ONLY SMALL ADJUSTMENTS WERE MADE TO CLEAN
UP BORDERS AND CONTINUE TO SLOW TREND TEMPERATURES UPWARD TOWARD
NORMAL THROUGH THE PERIOD.

THE REGION CONTINUES TO BE IMPACTED BY NORTHERN PORTION OF A
STRETCHED OUT UPPER LOW INTO NORTHEAST WYOMING AS IT MOVES INTO
THE DAKOTAS ON SUNDAY. PERSISTENT EAST TO SOUTHEAST SURFACE FLOW
WILL SUPPORT PWATS INTO THE ONE INCH RANGE IN SOUTHEAST MONTANA.
DEEP MOISTURE AVAILABILITY SHOULD ALLOW FOR A GOOD CHANCE FOR
SHOWERS...ESPECIALLY EAST OF BILLINGS. ATMOSPHERE DOES NOT APPEAR
VERY UNSTABLE...SO EXPECT LESS CHANCE OF THUNDER. IMPACTS TO THE
EAST WILL SLOWLY DECREASE THOUGHT MONDAY.

THERE IS SOME INDICATION OF A SHORT PERIOD OF SHORTWAVE RIDGING
ACROSS THE REGION MONDAY NIGHT...AHEAD OF THE NEXT SYSTEM. THIS
WILL BRING A BREAK IN PRECIP OVERNIGHT...BUT TIMING OF THE NEXT
SYSTEM SHOULD KEEP SOME CLOUD COVER IN PLACE AS MOISTURE CONTINUES
TO FLOW INTO THE WESTERN MOUNTAINS.

THE NEXT UPPER LEVEL LOW PRESSURE SYSTEM WILL DROP INTO THE REGION
FROM BRITISH COLUMBIA ON TUESDAY OR WEDNESDAY DEPENDING ON WHICH
MODEL YOU FAVOR. THE EC IS CURRENTLY MUCH FASTER BRINGING THE
SYSTEM INTO THE REGION...AND KEEPING IT OVER THE REGION UNTIL
THURSDAY MORNING. THE GFS HOLD THE LOW TO THE WEST UNTIL
WEDNESDAY...BUT KEEPS IT OVER THE REGION THROUGH THE END OF THE
PERIOD. HAVE GOING POPS INTACT...AS GFS HAS MADE SIGNIFICANT
CHANGE THIS RUN...BUT WILL BE WORTH FURTHER ATTENTION ON LATER
SHIFT. AAG

&&

.AVIATION...

ISOLATED SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO LATE EVENING
ALONG AND NEAR AREA MOUNTAINS. LOCAL MVFR TO IFR CONDITIONS CAN
BE EXPECTED NEAR THIS ACTIVITY. THERE IS A VERY SLIGHT CHANCE FOR
PATCHY LOW LYING FOG OR STRATUS DEVELOPMENT AROUND SUNRISE JUST
ABOUT EVERYWHERE. WILL MONITOR THIS POTENTIAL OVERNIGHT. OTHERWISE
VFR CONDITIONS ARE EXPECTED OVERNIGHT. CHAMBERS
&&

.PRELIMINARY POINT TEMP/POPS...

    FRI     SAT     SUN     MON     TUE     WED     THU
-----------------------------------------------------------
BIL 044/071 046/064 046/063 045/070 048/070 048/072 047/068
    03/T    23/T    23/T    32/T    23/T    33/T    33/T
LVM 040/067 044/060 042/061 039/066 043/066 044/067 041/066
    24/T    35/T    43/T    33/T    34/T    44/T    43/T
HDN 044/073 045/066 046/064 045/072 047/073 048/075 047/071
    03/T    23/T    33/T    32/T    23/T    33/T    33/T
MLS 045/073 046/065 046/064 047/069 046/072 049/073 048/069
    01/B    12/T    34/T    43/T    22/T    23/T    33/T
4BQ 044/068 043/062 046/060 045/068 045/072 048/073 048/069
    02/T    25/T    36/T    43/T    23/T    33/T    34/T
BHK 041/069 042/060 044/061 044/065 043/069 046/069 045/066
    01/N    25/T    46/T    55/T    33/T    33/T    33/T
SHR 041/064 041/060 043/058 041/068 043/069 044/070 045/067
    13/T    25/T    44/T    32/T    24/T    43/T    33/T

&&

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

&&

$$
WEATHER.GOV/BILLINGS



000
FXUS65 KBYZ 220254
AFDBYZ

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
854 PM MDT THU MAY 21 2015

.UPDATE...
UPDATED FORECAST TO REMOVE THE EARLY EVENING POPS THAT INCLUDED A
CHANCE OF THUNDERSTORMS OVER AND NEAR THE MOUNTAINS. AIRMASS WAS
STABILIZING BASED ON MESOANALYSIS SO WOULD NOT EXPECT ANY MORE
THUNDER OVERNIGHT. WEBCAMS AND SURFACE OBSERVATIONS SHOWED THAT
SHOWERS WERE CONFINED MAINLY TO THE MOUNTAINS THIS EVENING. KLVM
HAS BEEN REPORTING RAIN OVER THE LAST FEW HOURS...BUT ONLY LIGHT
RAIN WAS REPORTED RECENTLY. MOISTURE WAS ADVECTING N THIS EVENING
PER SATELLITE IMAGERY AHEAD OF A STRONG WAVE OVER AZ/NM. MODELS
SHOWED THIS WAVE MOVING N AND WEAKENING OVERNIGHT...SUPPORTING
LIGHT QPF OVER THE SOUTHERN MOUNTAINS. POPS REFLECTED LATEST
OBSERVED AND MODEL TRENDS. RAISED DEWPOINTS W OF KBIL PER LATEST
GUIDANCE AND DUE TO THE SHOWER ACTIVITY. EXPECT HIGH HUMIDITIES
OVER THE W OVERNIGHT. THE HUMIDITY COMBINED WITH RECENT RAINFALL
WILL SUPPORT PATCHY FOG. ADJUSTED SKY COVER THROUGH 06Z TO FIT
LATEST SATELLITE TRENDS.

WEAK UPPER FLOW WITH SOME LIFT FROM SHORTWAVES WILL BE OVER THE
AREA ON FRI ALONG WITH SE FLOW CONTINUING TO PUMP MOISTURE INTO
THE REGION. SPC PLUMES SHOWED HIGHER CAPE VALUES FRI AFTERNOON
BUT WEAK SHEAR. WILL HAVE ANOTHER ROUND OF MOUNTAIN SHOWERS AND
THUNDERSTORMS WITH SOME ACTIVITY SPREADING OUT ONTO THE PLAINS.
ARTHUR

&&

.SHORT TERM...VALID FOR FRI AND SAT...

SOMEWHAT BENIGN FLOW OVER THE REGION TODAY AS UPPER LOW OFF
CALIFORNIA COAST TRACKS INTO SOUTHERN CALIFORNIA BY EVENING.
WE HAVE SOME MOISTURE THAT HAS ADVECTED INTO WESTERN MONTANA
WHILE THE EAST REMAINS GENERALLY DRY. SO ISOLATED TO SCATTERED
SHOWERS AND MAYBE SOME THUNDER IS EXPECTED THROUGH THE
EVENING...WITH A BIT LINGERING OVERNIGHT. FLOW IS WEAK SO WE DONT
EXPECT THOSE SHOWERS TO MAKE MUCH HEADWAY INTO THE PLAINS.
SOUTHERLY FLOW AND MAYBE AN INCREASE IN HIGH CLOUDS TONIGHT SO I
DO NOT THINK WE WILL GET QUITE AS CHILLY AS WE HAVE BEEN RECENTLY.

FRIDAY/FRIDAY NIGHT...UPPER LOW TRACKS INTO THE DESERT SOUTHWEST
WITH A PIECE OF ENERGY EJECTING OUT AHEAD OF IT IN THE SOUTH TO
NORTH FLOW ALOFT. THIS WILL PUSH INTO WYOMING BY AFTERNOON AND
SPREAD SOME SHOWERS AND PERHAPS SOME THUNDERSTORMS INTO OUR
FORECAST AREA. I LEFT THE HIGHEST POPS OVER THE HIGH COUNTRY TO
THE WEST...REDUCED THE PPS A BIT FOR THE NORTH CENTRAL ZONES
NORTH OF I-94 BASED ON CURRENT PROGGS TRACKING THIS SHORT WAVE
ENERGY. LOOK FOR TEMPS EQUAL TO OR A LITTLE HIGHER THAN TODAYS ON
FRIDAY AS WARMER AIR ADVECTS NORTHWARD THANKS TO THE SOUTHERLY
FLOW.

THAT UPPER LOW PUSHES INTO THE CENTRAL ROCKIES FOR THE START OF
THE WEEKEND. ITS INFLUENCE WILL CONTINUE TO PRODUCE INCREASING
PRECIPITABLE WATERS ACROSS OUR FORECAST AREA. THUS THE WIDESPREAD
SHOWERS AND SOME THUNDERSTORMS WE ARE ADVERTISING FOR SATURDAY AND
SATURDAY NIGHT LOOKS ON TRACK. WEAK WIND FIELDS SHOULD NOT SUPPORT
ANY ORGANIZED SEVERE THREAT...THOUGH AS LAST WEEK INDICATED...AN
ISOLATED STORM WITH LARGER HAIL CANNOT BE COMPLETELY RULED OUT. BT


.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...

OVERALL EXTENDED FORECAST APPEARS IN GOOD SHAPE...WITH BROAD
UPPER LEVEL TROF IN CONTROL OVER THE REGION THROUGHOUT THE
MAJORITY OF THE PERIOD. ONLY SMALL ADJUSTMENTS WERE MADE TO CLEAN
UP BORDERS AND CONTINUE TO SLOW TREND TEMPERATURES UPWARD TOWARD
NORMAL THROUGH THE PERIOD.

THE REGION CONTINUES TO BE IMPACTED BY NORTHERN PORTION OF A
STRETCHED OUT UPPER LOW INTO NORTHEAST WYOMING AS IT MOVES INTO
THE DAKOTAS ON SUNDAY. PERSISTENT EAST TO SOUTHEAST SURFACE FLOW
WILL SUPPORT PWATS INTO THE ONE INCH RANGE IN SOUTHEAST MONTANA.
DEEP MOISTURE AVAILABILITY SHOULD ALLOW FOR A GOOD CHANCE FOR
SHOWERS...ESPECIALLY EAST OF BILLINGS. ATMOSPHERE DOES NOT APPEAR
VERY UNSTABLE...SO EXPECT LESS CHANCE OF THUNDER. IMPACTS TO THE
EAST WILL SLOWLY DECREASE THOUGHT MONDAY.

THERE IS SOME INDICATION OF A SHORT PERIOD OF SHORTWAVE RIDGING
ACROSS THE REGION MONDAY NIGHT...AHEAD OF THE NEXT SYSTEM. THIS
WILL BRING A BREAK IN PRECIP OVERNIGHT...BUT TIMING OF THE NEXT
SYSTEM SHOULD KEEP SOME CLOUD COVER IN PLACE AS MOISTURE CONTINUES
TO FLOW INTO THE WESTERN MOUNTAINS.

THE NEXT UPPER LEVEL LOW PRESSURE SYSTEM WILL DROP INTO THE REGION
FROM BRITISH COLUMBIA ON TUESDAY OR WEDNESDAY DEPENDING ON WHICH
MODEL YOU FAVOR. THE EC IS CURRENTLY MUCH FASTER BRINGING THE
SYSTEM INTO THE REGION...AND KEEPING IT OVER THE REGION UNTIL
THURSDAY MORNING. THE GFS HOLD THE LOW TO THE WEST UNTIL
WEDNESDAY...BUT KEEPS IT OVER THE REGION THROUGH THE END OF THE
PERIOD. HAVE GOING POPS INTACT...AS GFS HAS MADE SIGNIFICANT
CHANGE THIS RUN...BUT WILL BE WORTH FURTHER ATTENTION ON LATER
SHIFT. AAG

&&

.AVIATION...

ISOLATED SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO LATE EVENING
ALONG AND NEAR AREA MOUNTAINS. LOCAL MVFR TO IFR CONDITIONS CAN
BE EXPECTED NEAR THIS ACTIVITY. THERE IS A VERY SLIGHT CHANCE FOR
PATCHY LOW LYING FOG OR STRATUS DEVELOPMENT AROUND SUNRISE JUST
ABOUT EVERYWHERE. WILL MONITOR THIS POTENTIAL OVERNIGHT. OTHERWISE
VFR CONDITIONS ARE EXPECTED OVERNIGHT. CHAMBERS
&&

.PRELIMINARY POINT TEMP/POPS...

    FRI     SAT     SUN     MON     TUE     WED     THU
-----------------------------------------------------------
BIL 044/071 046/064 046/063 045/070 048/070 048/072 047/068
    03/T    23/T    23/T    32/T    23/T    33/T    33/T
LVM 040/067 044/060 042/061 039/066 043/066 044/067 041/066
    24/T    35/T    43/T    33/T    34/T    44/T    43/T
HDN 044/073 045/066 046/064 045/072 047/073 048/075 047/071
    03/T    23/T    33/T    32/T    23/T    33/T    33/T
MLS 045/073 046/065 046/064 047/069 046/072 049/073 048/069
    01/B    12/T    34/T    43/T    22/T    23/T    33/T
4BQ 044/068 043/062 046/060 045/068 045/072 048/073 048/069
    02/T    25/T    36/T    43/T    23/T    33/T    34/T
BHK 041/069 042/060 044/061 044/065 043/069 046/069 045/066
    01/N    25/T    46/T    55/T    33/T    33/T    33/T
SHR 041/064 041/060 043/058 041/068 043/069 044/070 045/067
    13/T    25/T    44/T    32/T    24/T    43/T    33/T

&&

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

&&

$$
WEATHER.GOV/BILLINGS



000
FXUS65 KBYZ 220254
AFDBYZ

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
854 PM MDT THU MAY 21 2015

.UPDATE...
UPDATED FORECAST TO REMOVE THE EARLY EVENING POPS THAT INCLUDED A
CHANCE OF THUNDERSTORMS OVER AND NEAR THE MOUNTAINS. AIRMASS WAS
STABILIZING BASED ON MESOANALYSIS SO WOULD NOT EXPECT ANY MORE
THUNDER OVERNIGHT. WEBCAMS AND SURFACE OBSERVATIONS SHOWED THAT
SHOWERS WERE CONFINED MAINLY TO THE MOUNTAINS THIS EVENING. KLVM
HAS BEEN REPORTING RAIN OVER THE LAST FEW HOURS...BUT ONLY LIGHT
RAIN WAS REPORTED RECENTLY. MOISTURE WAS ADVECTING N THIS EVENING
PER SATELLITE IMAGERY AHEAD OF A STRONG WAVE OVER AZ/NM. MODELS
SHOWED THIS WAVE MOVING N AND WEAKENING OVERNIGHT...SUPPORTING
LIGHT QPF OVER THE SOUTHERN MOUNTAINS. POPS REFLECTED LATEST
OBSERVED AND MODEL TRENDS. RAISED DEWPOINTS W OF KBIL PER LATEST
GUIDANCE AND DUE TO THE SHOWER ACTIVITY. EXPECT HIGH HUMIDITIES
OVER THE W OVERNIGHT. THE HUMIDITY COMBINED WITH RECENT RAINFALL
WILL SUPPORT PATCHY FOG. ADJUSTED SKY COVER THROUGH 06Z TO FIT
LATEST SATELLITE TRENDS.

WEAK UPPER FLOW WITH SOME LIFT FROM SHORTWAVES WILL BE OVER THE
AREA ON FRI ALONG WITH SE FLOW CONTINUING TO PUMP MOISTURE INTO
THE REGION. SPC PLUMES SHOWED HIGHER CAPE VALUES FRI AFTERNOON
BUT WEAK SHEAR. WILL HAVE ANOTHER ROUND OF MOUNTAIN SHOWERS AND
THUNDERSTORMS WITH SOME ACTIVITY SPREADING OUT ONTO THE PLAINS.
ARTHUR

&&

.SHORT TERM...VALID FOR FRI AND SAT...

SOMEWHAT BENIGN FLOW OVER THE REGION TODAY AS UPPER LOW OFF
CALIFORNIA COAST TRACKS INTO SOUTHERN CALIFORNIA BY EVENING.
WE HAVE SOME MOISTURE THAT HAS ADVECTED INTO WESTERN MONTANA
WHILE THE EAST REMAINS GENERALLY DRY. SO ISOLATED TO SCATTERED
SHOWERS AND MAYBE SOME THUNDER IS EXPECTED THROUGH THE
EVENING...WITH A BIT LINGERING OVERNIGHT. FLOW IS WEAK SO WE DONT
EXPECT THOSE SHOWERS TO MAKE MUCH HEADWAY INTO THE PLAINS.
SOUTHERLY FLOW AND MAYBE AN INCREASE IN HIGH CLOUDS TONIGHT SO I
DO NOT THINK WE WILL GET QUITE AS CHILLY AS WE HAVE BEEN RECENTLY.

FRIDAY/FRIDAY NIGHT...UPPER LOW TRACKS INTO THE DESERT SOUTHWEST
WITH A PIECE OF ENERGY EJECTING OUT AHEAD OF IT IN THE SOUTH TO
NORTH FLOW ALOFT. THIS WILL PUSH INTO WYOMING BY AFTERNOON AND
SPREAD SOME SHOWERS AND PERHAPS SOME THUNDERSTORMS INTO OUR
FORECAST AREA. I LEFT THE HIGHEST POPS OVER THE HIGH COUNTRY TO
THE WEST...REDUCED THE PPS A BIT FOR THE NORTH CENTRAL ZONES
NORTH OF I-94 BASED ON CURRENT PROGGS TRACKING THIS SHORT WAVE
ENERGY. LOOK FOR TEMPS EQUAL TO OR A LITTLE HIGHER THAN TODAYS ON
FRIDAY AS WARMER AIR ADVECTS NORTHWARD THANKS TO THE SOUTHERLY
FLOW.

THAT UPPER LOW PUSHES INTO THE CENTRAL ROCKIES FOR THE START OF
THE WEEKEND. ITS INFLUENCE WILL CONTINUE TO PRODUCE INCREASING
PRECIPITABLE WATERS ACROSS OUR FORECAST AREA. THUS THE WIDESPREAD
SHOWERS AND SOME THUNDERSTORMS WE ARE ADVERTISING FOR SATURDAY AND
SATURDAY NIGHT LOOKS ON TRACK. WEAK WIND FIELDS SHOULD NOT SUPPORT
ANY ORGANIZED SEVERE THREAT...THOUGH AS LAST WEEK INDICATED...AN
ISOLATED STORM WITH LARGER HAIL CANNOT BE COMPLETELY RULED OUT. BT


.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...

OVERALL EXTENDED FORECAST APPEARS IN GOOD SHAPE...WITH BROAD
UPPER LEVEL TROF IN CONTROL OVER THE REGION THROUGHOUT THE
MAJORITY OF THE PERIOD. ONLY SMALL ADJUSTMENTS WERE MADE TO CLEAN
UP BORDERS AND CONTINUE TO SLOW TREND TEMPERATURES UPWARD TOWARD
NORMAL THROUGH THE PERIOD.

THE REGION CONTINUES TO BE IMPACTED BY NORTHERN PORTION OF A
STRETCHED OUT UPPER LOW INTO NORTHEAST WYOMING AS IT MOVES INTO
THE DAKOTAS ON SUNDAY. PERSISTENT EAST TO SOUTHEAST SURFACE FLOW
WILL SUPPORT PWATS INTO THE ONE INCH RANGE IN SOUTHEAST MONTANA.
DEEP MOISTURE AVAILABILITY SHOULD ALLOW FOR A GOOD CHANCE FOR
SHOWERS...ESPECIALLY EAST OF BILLINGS. ATMOSPHERE DOES NOT APPEAR
VERY UNSTABLE...SO EXPECT LESS CHANCE OF THUNDER. IMPACTS TO THE
EAST WILL SLOWLY DECREASE THOUGHT MONDAY.

THERE IS SOME INDICATION OF A SHORT PERIOD OF SHORTWAVE RIDGING
ACROSS THE REGION MONDAY NIGHT...AHEAD OF THE NEXT SYSTEM. THIS
WILL BRING A BREAK IN PRECIP OVERNIGHT...BUT TIMING OF THE NEXT
SYSTEM SHOULD KEEP SOME CLOUD COVER IN PLACE AS MOISTURE CONTINUES
TO FLOW INTO THE WESTERN MOUNTAINS.

THE NEXT UPPER LEVEL LOW PRESSURE SYSTEM WILL DROP INTO THE REGION
FROM BRITISH COLUMBIA ON TUESDAY OR WEDNESDAY DEPENDING ON WHICH
MODEL YOU FAVOR. THE EC IS CURRENTLY MUCH FASTER BRINGING THE
SYSTEM INTO THE REGION...AND KEEPING IT OVER THE REGION UNTIL
THURSDAY MORNING. THE GFS HOLD THE LOW TO THE WEST UNTIL
WEDNESDAY...BUT KEEPS IT OVER THE REGION THROUGH THE END OF THE
PERIOD. HAVE GOING POPS INTACT...AS GFS HAS MADE SIGNIFICANT
CHANGE THIS RUN...BUT WILL BE WORTH FURTHER ATTENTION ON LATER
SHIFT. AAG

&&

.AVIATION...

ISOLATED SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO LATE EVENING
ALONG AND NEAR AREA MOUNTAINS. LOCAL MVFR TO IFR CONDITIONS CAN
BE EXPECTED NEAR THIS ACTIVITY. THERE IS A VERY SLIGHT CHANCE FOR
PATCHY LOW LYING FOG OR STRATUS DEVELOPMENT AROUND SUNRISE JUST
ABOUT EVERYWHERE. WILL MONITOR THIS POTENTIAL OVERNIGHT. OTHERWISE
VFR CONDITIONS ARE EXPECTED OVERNIGHT. CHAMBERS
&&

.PRELIMINARY POINT TEMP/POPS...

    FRI     SAT     SUN     MON     TUE     WED     THU
-----------------------------------------------------------
BIL 044/071 046/064 046/063 045/070 048/070 048/072 047/068
    03/T    23/T    23/T    32/T    23/T    33/T    33/T
LVM 040/067 044/060 042/061 039/066 043/066 044/067 041/066
    24/T    35/T    43/T    33/T    34/T    44/T    43/T
HDN 044/073 045/066 046/064 045/072 047/073 048/075 047/071
    03/T    23/T    33/T    32/T    23/T    33/T    33/T
MLS 045/073 046/065 046/064 047/069 046/072 049/073 048/069
    01/B    12/T    34/T    43/T    22/T    23/T    33/T
4BQ 044/068 043/062 046/060 045/068 045/072 048/073 048/069
    02/T    25/T    36/T    43/T    23/T    33/T    34/T
BHK 041/069 042/060 044/061 044/065 043/069 046/069 045/066
    01/N    25/T    46/T    55/T    33/T    33/T    33/T
SHR 041/064 041/060 043/058 041/068 043/069 044/070 045/067
    13/T    25/T    44/T    32/T    24/T    43/T    33/T

&&

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

&&

$$
WEATHER.GOV/BILLINGS



000
FXUS65 KTFX 212322
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
520 PM MDT THU MAY 21 2015

UPDATED AVIATION DISCUSSION

.DISCUSSION...

TONIGHT THROUGH SATURDAY...RELATIVELY LIGHT UPPER LEVEL FLOW FROM
THE SOUTHEAST WILL CONTINUE OVERNIGHT BUT IS EXPECTED TO SHIFT
EAST-NORTHEAST AND INCREASE BY SATURDAY. SCATTERED TO NUMEROUS
SHOWERS AND A FEW THUNDERSTORMS CAN BE EXPECTED ACROSS SOUTHWEST
MONTANA THIS AFTERNOON AND EVENING BEFORE TAPERING OFF TO ISOLATED
SHOWERS OVERNIGHT. ISOLATED CONVECTION COULD REACH SOUTHERN PORTIONS
OF CENTRAL MONTANA THIS AFTERNOON AND EVENING AS WELL. HOWEVER,
FROM FRIDAY EVENING THROUGH SATURDAY AFTERNOON SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS SPREAD ACROSS CENTRAL AND NORTH
CENTRAL MONTANA AS WELL. AS HAS BEEN MENTIONED OVER THE LAST FEW
DAYS, I AM NOT EXPECTED ANY SEVERE WEATHER AS CAPE AND SHEAR
REMAIN RELATIVELY WEAK. MPJ

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.AVIATION... UPDATED 0000Z.

A RELATIVELY MORE MOIST/UNSTABLE AIRMASS HAS MOVED NORTH INTO SW MT
WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS
EVENING...MAINLY SOUTH OF KHLN TO KGTF. BRIEF MVFR CONDITIONS ARE
POSSIBLE UNDER THESE CELLS THIS EVENING WITH LOCAL TERRAIN
OBSCURATIONS. VFR CONDITIONS WILL PREVAIL OTHERWISE WITH SHOWERS AND
THUNDERSTORMS ENDING BY MIDNIGHT. EAST TO SOUTHEAST SURFACE WINDS
WILL CONTINUE THROUGH TOMORROW AND MAY BE LOCALLY GUSTY AT TIMES AT
THE KLWT AND KHVR TERMINALS. AREA OF MOISTURE/INSTABILITY SPREADS
FURTHER NORTH FRIDAY AFTERNOON WITH SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS POSSIBLE FURTHER NORTH INTO NORTH CENTRAL MT BY FRIDAY
EVENING. HOENISCH

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  43  70  46  67 /  10  20  30  40
CTB  37  69  41  68 /   0  10  10  20
HLN  45  72  48  67 /  30  30  30  60
BZN  39  69  42  64 /  30  40  30  50
WEY  32  61  34  58 /  40  50  60  60
DLN  41  66  44  64 /  50  40  30  50
HVR  38  73  43  73 /   0  10  30  20
LWT  41  69  45  64 /   0  40  40  40

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 212322
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
520 PM MDT THU MAY 21 2015

UPDATED AVIATION DISCUSSION

.DISCUSSION...

TONIGHT THROUGH SATURDAY...RELATIVELY LIGHT UPPER LEVEL FLOW FROM
THE SOUTHEAST WILL CONTINUE OVERNIGHT BUT IS EXPECTED TO SHIFT
EAST-NORTHEAST AND INCREASE BY SATURDAY. SCATTERED TO NUMEROUS
SHOWERS AND A FEW THUNDERSTORMS CAN BE EXPECTED ACROSS SOUTHWEST
MONTANA THIS AFTERNOON AND EVENING BEFORE TAPERING OFF TO ISOLATED
SHOWERS OVERNIGHT. ISOLATED CONVECTION COULD REACH SOUTHERN PORTIONS
OF CENTRAL MONTANA THIS AFTERNOON AND EVENING AS WELL. HOWEVER,
FROM FRIDAY EVENING THROUGH SATURDAY AFTERNOON SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS SPREAD ACROSS CENTRAL AND NORTH
CENTRAL MONTANA AS WELL. AS HAS BEEN MENTIONED OVER THE LAST FEW
DAYS, I AM NOT EXPECTED ANY SEVERE WEATHER AS CAPE AND SHEAR
REMAIN RELATIVELY WEAK. MPJ

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.AVIATION... UPDATED 0000Z.

A RELATIVELY MORE MOIST/UNSTABLE AIRMASS HAS MOVED NORTH INTO SW MT
WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS
EVENING...MAINLY SOUTH OF KHLN TO KGTF. BRIEF MVFR CONDITIONS ARE
POSSIBLE UNDER THESE CELLS THIS EVENING WITH LOCAL TERRAIN
OBSCURATIONS. VFR CONDITIONS WILL PREVAIL OTHERWISE WITH SHOWERS AND
THUNDERSTORMS ENDING BY MIDNIGHT. EAST TO SOUTHEAST SURFACE WINDS
WILL CONTINUE THROUGH TOMORROW AND MAY BE LOCALLY GUSTY AT TIMES AT
THE KLWT AND KHVR TERMINALS. AREA OF MOISTURE/INSTABILITY SPREADS
FURTHER NORTH FRIDAY AFTERNOON WITH SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS POSSIBLE FURTHER NORTH INTO NORTH CENTRAL MT BY FRIDAY
EVENING. HOENISCH

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  43  70  46  67 /  10  20  30  40
CTB  37  69  41  68 /   0  10  10  20
HLN  45  72  48  67 /  30  30  30  60
BZN  39  69  42  64 /  30  40  30  50
WEY  32  61  34  58 /  40  50  60  60
DLN  41  66  44  64 /  50  40  30  50
HVR  38  73  43  73 /   0  10  30  20
LWT  41  69  45  64 /   0  40  40  40

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 212322
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
520 PM MDT THU MAY 21 2015

UPDATED AVIATION DISCUSSION

.DISCUSSION...

TONIGHT THROUGH SATURDAY...RELATIVELY LIGHT UPPER LEVEL FLOW FROM
THE SOUTHEAST WILL CONTINUE OVERNIGHT BUT IS EXPECTED TO SHIFT
EAST-NORTHEAST AND INCREASE BY SATURDAY. SCATTERED TO NUMEROUS
SHOWERS AND A FEW THUNDERSTORMS CAN BE EXPECTED ACROSS SOUTHWEST
MONTANA THIS AFTERNOON AND EVENING BEFORE TAPERING OFF TO ISOLATED
SHOWERS OVERNIGHT. ISOLATED CONVECTION COULD REACH SOUTHERN PORTIONS
OF CENTRAL MONTANA THIS AFTERNOON AND EVENING AS WELL. HOWEVER,
FROM FRIDAY EVENING THROUGH SATURDAY AFTERNOON SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS SPREAD ACROSS CENTRAL AND NORTH
CENTRAL MONTANA AS WELL. AS HAS BEEN MENTIONED OVER THE LAST FEW
DAYS, I AM NOT EXPECTED ANY SEVERE WEATHER AS CAPE AND SHEAR
REMAIN RELATIVELY WEAK. MPJ

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.AVIATION... UPDATED 0000Z.

A RELATIVELY MORE MOIST/UNSTABLE AIRMASS HAS MOVED NORTH INTO SW MT
WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS
EVENING...MAINLY SOUTH OF KHLN TO KGTF. BRIEF MVFR CONDITIONS ARE
POSSIBLE UNDER THESE CELLS THIS EVENING WITH LOCAL TERRAIN
OBSCURATIONS. VFR CONDITIONS WILL PREVAIL OTHERWISE WITH SHOWERS AND
THUNDERSTORMS ENDING BY MIDNIGHT. EAST TO SOUTHEAST SURFACE WINDS
WILL CONTINUE THROUGH TOMORROW AND MAY BE LOCALLY GUSTY AT TIMES AT
THE KLWT AND KHVR TERMINALS. AREA OF MOISTURE/INSTABILITY SPREADS
FURTHER NORTH FRIDAY AFTERNOON WITH SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS POSSIBLE FURTHER NORTH INTO NORTH CENTRAL MT BY FRIDAY
EVENING. HOENISCH

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  43  70  46  67 /  10  20  30  40
CTB  37  69  41  68 /   0  10  10  20
HLN  45  72  48  67 /  30  30  30  60
BZN  39  69  42  64 /  30  40  30  50
WEY  32  61  34  58 /  40  50  60  60
DLN  41  66  44  64 /  50  40  30  50
HVR  38  73  43  73 /   0  10  30  20
LWT  41  69  45  64 /   0  40  40  40

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 212322
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
520 PM MDT THU MAY 21 2015

UPDATED AVIATION DISCUSSION

.DISCUSSION...

TONIGHT THROUGH SATURDAY...RELATIVELY LIGHT UPPER LEVEL FLOW FROM
THE SOUTHEAST WILL CONTINUE OVERNIGHT BUT IS EXPECTED TO SHIFT
EAST-NORTHEAST AND INCREASE BY SATURDAY. SCATTERED TO NUMEROUS
SHOWERS AND A FEW THUNDERSTORMS CAN BE EXPECTED ACROSS SOUTHWEST
MONTANA THIS AFTERNOON AND EVENING BEFORE TAPERING OFF TO ISOLATED
SHOWERS OVERNIGHT. ISOLATED CONVECTION COULD REACH SOUTHERN PORTIONS
OF CENTRAL MONTANA THIS AFTERNOON AND EVENING AS WELL. HOWEVER,
FROM FRIDAY EVENING THROUGH SATURDAY AFTERNOON SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS SPREAD ACROSS CENTRAL AND NORTH
CENTRAL MONTANA AS WELL. AS HAS BEEN MENTIONED OVER THE LAST FEW
DAYS, I AM NOT EXPECTED ANY SEVERE WEATHER AS CAPE AND SHEAR
REMAIN RELATIVELY WEAK. MPJ

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.AVIATION... UPDATED 0000Z.

A RELATIVELY MORE MOIST/UNSTABLE AIRMASS HAS MOVED NORTH INTO SW MT
WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS
EVENING...MAINLY SOUTH OF KHLN TO KGTF. BRIEF MVFR CONDITIONS ARE
POSSIBLE UNDER THESE CELLS THIS EVENING WITH LOCAL TERRAIN
OBSCURATIONS. VFR CONDITIONS WILL PREVAIL OTHERWISE WITH SHOWERS AND
THUNDERSTORMS ENDING BY MIDNIGHT. EAST TO SOUTHEAST SURFACE WINDS
WILL CONTINUE THROUGH TOMORROW AND MAY BE LOCALLY GUSTY AT TIMES AT
THE KLWT AND KHVR TERMINALS. AREA OF MOISTURE/INSTABILITY SPREADS
FURTHER NORTH FRIDAY AFTERNOON WITH SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS POSSIBLE FURTHER NORTH INTO NORTH CENTRAL MT BY FRIDAY
EVENING. HOENISCH

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  43  70  46  67 /  10  20  30  40
CTB  37  69  41  68 /   0  10  10  20
HLN  45  72  48  67 /  30  30  30  60
BZN  39  69  42  64 /  30  40  30  50
WEY  32  61  34  58 /  40  50  60  60
DLN  41  66  44  64 /  50  40  30  50
HVR  38  73  43  73 /   0  10  30  20
LWT  41  69  45  64 /   0  40  40  40

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 212322
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
520 PM MDT THU MAY 21 2015

UPDATED AVIATION DISCUSSION

.DISCUSSION...

TONIGHT THROUGH SATURDAY...RELATIVELY LIGHT UPPER LEVEL FLOW FROM
THE SOUTHEAST WILL CONTINUE OVERNIGHT BUT IS EXPECTED TO SHIFT
EAST-NORTHEAST AND INCREASE BY SATURDAY. SCATTERED TO NUMEROUS
SHOWERS AND A FEW THUNDERSTORMS CAN BE EXPECTED ACROSS SOUTHWEST
MONTANA THIS AFTERNOON AND EVENING BEFORE TAPERING OFF TO ISOLATED
SHOWERS OVERNIGHT. ISOLATED CONVECTION COULD REACH SOUTHERN PORTIONS
OF CENTRAL MONTANA THIS AFTERNOON AND EVENING AS WELL. HOWEVER,
FROM FRIDAY EVENING THROUGH SATURDAY AFTERNOON SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS SPREAD ACROSS CENTRAL AND NORTH
CENTRAL MONTANA AS WELL. AS HAS BEEN MENTIONED OVER THE LAST FEW
DAYS, I AM NOT EXPECTED ANY SEVERE WEATHER AS CAPE AND SHEAR
REMAIN RELATIVELY WEAK. MPJ

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.AVIATION... UPDATED 0000Z.

A RELATIVELY MORE MOIST/UNSTABLE AIRMASS HAS MOVED NORTH INTO SW MT
WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS
EVENING...MAINLY SOUTH OF KHLN TO KGTF. BRIEF MVFR CONDITIONS ARE
POSSIBLE UNDER THESE CELLS THIS EVENING WITH LOCAL TERRAIN
OBSCURATIONS. VFR CONDITIONS WILL PREVAIL OTHERWISE WITH SHOWERS AND
THUNDERSTORMS ENDING BY MIDNIGHT. EAST TO SOUTHEAST SURFACE WINDS
WILL CONTINUE THROUGH TOMORROW AND MAY BE LOCALLY GUSTY AT TIMES AT
THE KLWT AND KHVR TERMINALS. AREA OF MOISTURE/INSTABILITY SPREADS
FURTHER NORTH FRIDAY AFTERNOON WITH SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS POSSIBLE FURTHER NORTH INTO NORTH CENTRAL MT BY FRIDAY
EVENING. HOENISCH

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  43  70  46  67 /  10  20  30  40
CTB  37  69  41  68 /   0  10  10  20
HLN  45  72  48  67 /  30  30  30  60
BZN  39  69  42  64 /  30  40  30  50
WEY  32  61  34  58 /  40  50  60  60
DLN  41  66  44  64 /  50  40  30  50
HVR  38  73  43  73 /   0  10  30  20
LWT  41  69  45  64 /   0  40  40  40

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KBYZ 212102
AFDBYZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
302 PM MDT THU MAY 21 2015

.SHORT TERM...VALID FOR FRI AND SAT...

SOMEWHAT BENIGN FLOW OVER THE REGION TODAY AS UPPER LOW OFF
CALIFORNIA COAST TRACKS INTO SOUTHERN CALIFORNIA BY EVENING.
WE HAVE SOME MOISTURE THAT HAS ADVECTED INTO WESTERN MONTANA
WHILE THE EAST REMAINS GENERALLY DRY. SO ISOLATED TO SCATTERED
SHOWERS AND MAYBE SOME THUNDER IS EXPECTED THROUGH THE
EVENING...WITH A BIT LINGERING OVERNIGHT. FLOW IS WEAK SO WE DONT
EXPECT THOSE SHOWERS TO MAKE MUCH HEADWAY INTO THE PLAINS.
SOUTHERLY FLOW AND MAYBE AN INCREASE IN HIGH CLOUDS TONIGHT SO I
DO NOT THINK WE WILL GET QUITE AS CHILLY AS WE HAVE BEEN RECENTLY.

FRIDAY/FRIDAY NIGHT...UPPER LOW TRACKS INTO THE DESERT SOUTHWEST
WITH A PIECE OF ENERGY EJECTING OUT AHEAD OF IT IN THE SOUTH TO
NORTH FLOW ALOFT. THIS WILL PUSH INTO WYOMING BY AFTERNOON AND
SPREAD SOME SHOWERS AND PERHAPS SOME THUNDERSTORMS INTO OUR
FORECAST AREA. I LEFT THE HIGHEST POPS OVER THE HIGH COUNTRY TO
THE WEST...REDUCED THE POPS A BIT FOR THE NORTH CENTRAL ZONES
NORTH OF I-94 BASED ON CURRENT PROGGS TRACKING THIS SHORT WAVE
ENERGY. LOOK FOR TEMPS EQUAL TO OR A LITTLE HIGHER THAN TODAYS ON
FRIDAY AS WARMER AIR ADVECTS NORTHWARD THANKS TO THE SOUTHERLY
FLOW.

THAT UPPER LOW PUSHES INTO THE CENTRAL ROCKIES FOR THE START OF
THE WEEKEND. ITS INFLUENCE WILL CONTINUE TO PRODUCE INCREASING
PRECIPITATABLE WATERS ACROSS OUR FORECAST AREA. THUS THE
WIDESPREAD SHOWERS AND SOME THUNDERSTORMS WE ARE ADVERTISING FOR
SATURDAY AND SATURDAY NIGHT LOOKS ON TRACK. WEAK WIND FIELDS
SHOULD NOT SUPPORT ANY ORGANIZED SEVERE THREAT...THOUGH AS LAST
WEEK INDICATED...AN ISOLATED STORM WITH LARGER HAIL CANNOT BE
COMPLETELY RULED OUT. BT

.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...

OVERALL EXTENDED FORECAST APPEARS IN GOOD SHAPE...WITH BROAD
UPPER LEVEL TROF IN CONTROL OVER THE REGION THROUGHOUT THE
MAJORITY OF THE PERIOD. ONLY SMALL ADJUSTMENTS WERE MADE TO CLEAN
UP BORDERS AND CONTINUE TO SLOW TREND TEMPERATURES UPWARD TOWARD
NORMAL THROUGH THE PERIOD.

THE REGION CONTINUES TO BE IMPACTED BY NORTHERN PORTION OF A
STRETCHED OUT UPPER LOW INTO NORTHEAST WYOMING AS IT MOVES INTO
THE DAKOTAS ON SUNDAY. PERSISTENT EAST TO SOUTHEAST SURFACE FLOW
WILL SUPPORT PWATS INTO THE ONE INCH RANGE IN SOUTHEAST MONTANA.
DEEP MOISTURE AVAILABILITY SHOULD ALLOW FOR A GOOD CHANCE FOR
SHOWERS...ESPECIALLY EAST OF BILLINGS. ATMOSPHERE DOES NOT APPEAR
VERY UNSTABLE...SO EXPECT LESS CHANCE OF THUNDER. IMPACTS TO THE
EAST WILL SLOWLY DECREASE THOUGHT MONDAY.

THERE IS SOME INDICATION OF A SHORT PERIOD OF SHORTWAVE RIDGING
ACROSS THE REGION MONDAY NIGHT...AHEAD OF THE NEXT SYSTEM. THIS
WILL BRING A BREAK IN PRECIP OVERNIGHT...BUT TIMING OF THE NEXT
SYSTEM SHOULD KEEP SOME CLOUD COVER IN PLACE AS MOISTURE CONTINUES
TO FLOW INTO THE WESTERN MOUNTAINS.

THE NEXT UPPER LEVEL LOW PRESSURE SYSTEM WILL DROP INTO THE REGION
FROM BRITISH COLUMBIA ON TUESDAY OR WEDNESDAY DEPENDING ON WHICH
MODEL YOU FAVOR. THE EC IS CURRENTLY MUCH FASTER BRINGING THE
SYSTEM INTO THE REGION...AND KEEPING IT OVER THE REGION UNTIL
THURSDAY MORNING. THE GFS HOLD THE LOW TO THE WEST UNTIL
WEDNESDAY...BUT KEEPS IT OVER THE REGION THROUGH THE END OF THE
PERIOD. HAVE GOING POPS INTACT...AS GFS HAS MADE SIGNIFICANT
CHANGE THIS RUN...BUT WILL BE WORTH FURTHER ATTENTION ON LATER
SHIFT. AAG

&&

.AVIATION...

EXPECTED CONTINUED MOUNTAIN SHOWER POTENTIAL TODAY AND
TONIGHT...AS AS A WEAK DISTURBANCE APPROACHES FROM SOUTHERN IDAHO
AND WESTERN MONTANA. SHOWERS WILL BE PRIMARILY CONFINED TO HIGHER
TERRAIN...BUT MAY IMPACT LIVINGSTON AND THE PARADISE VALLEY.
LOCALIZED MVFR CONDITIONS ARE POSSIBLE IN HEAVIER PRECIP. AT LEAST
OCCASIONAL MOUNTAIN OBSCURATION IS EXPECTED THROUGH THE REMAINDER
OF TODAY AND TONIGHT. SHOWERS WILL SPREAD ACROSS THE REGION ON
FRIDAY AFTERNOON...WITH LOCAL MVFR CONDITIONS POSSIBLE IN HEAVIER
PRECIP. AAG
&&

.PRELIMINARY POINT TEMP/POPS...

    FRI     SAT     SUN     MON     TUE     WED     THU
-----------------------------------------------------------
BIL 044/071 046/064 046/063 045/070 048/070 048/072 047/068
    03/T    23/T    23/T    32/T    23/T    33/T    33/T
LVM 040/067 044/060 042/061 039/066 043/066 044/067 041/066
    24/T    35/T    43/T    33/T    34/T    44/T    43/T
HDN 044/073 045/066 046/064 045/072 047/073 048/075 047/071
    03/T    23/T    33/T    32/T    23/T    33/T    33/T
MLS 045/073 046/065 046/064 047/069 046/072 049/073 048/069
    01/B    12/T    34/T    43/T    22/T    23/T    33/T
4BQ 044/068 043/062 046/060 045/068 045/072 048/073 048/069
    02/T    25/T    36/T    43/T    23/T    33/T    34/T
BHK 041/069 042/060 044/061 044/065 043/069 046/069 045/066
    01/N    25/T    46/T    55/T    33/T    33/T    33/T
SHR 041/064 041/060 043/058 041/068 043/069 044/070 045/067
    13/T    25/T    44/T    32/T    24/T    43/T    33/T

&&

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

&&

$$
WEATHER.GOV/BILLINGS



000
FXUS65 KBYZ 212102
AFDBYZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
302 PM MDT THU MAY 21 2015

.SHORT TERM...VALID FOR FRI AND SAT...

SOMEWHAT BENIGN FLOW OVER THE REGION TODAY AS UPPER LOW OFF
CALIFORNIA COAST TRACKS INTO SOUTHERN CALIFORNIA BY EVENING.
WE HAVE SOME MOISTURE THAT HAS ADVECTED INTO WESTERN MONTANA
WHILE THE EAST REMAINS GENERALLY DRY. SO ISOLATED TO SCATTERED
SHOWERS AND MAYBE SOME THUNDER IS EXPECTED THROUGH THE
EVENING...WITH A BIT LINGERING OVERNIGHT. FLOW IS WEAK SO WE DONT
EXPECT THOSE SHOWERS TO MAKE MUCH HEADWAY INTO THE PLAINS.
SOUTHERLY FLOW AND MAYBE AN INCREASE IN HIGH CLOUDS TONIGHT SO I
DO NOT THINK WE WILL GET QUITE AS CHILLY AS WE HAVE BEEN RECENTLY.

FRIDAY/FRIDAY NIGHT...UPPER LOW TRACKS INTO THE DESERT SOUTHWEST
WITH A PIECE OF ENERGY EJECTING OUT AHEAD OF IT IN THE SOUTH TO
NORTH FLOW ALOFT. THIS WILL PUSH INTO WYOMING BY AFTERNOON AND
SPREAD SOME SHOWERS AND PERHAPS SOME THUNDERSTORMS INTO OUR
FORECAST AREA. I LEFT THE HIGHEST POPS OVER THE HIGH COUNTRY TO
THE WEST...REDUCED THE POPS A BIT FOR THE NORTH CENTRAL ZONES
NORTH OF I-94 BASED ON CURRENT PROGGS TRACKING THIS SHORT WAVE
ENERGY. LOOK FOR TEMPS EQUAL TO OR A LITTLE HIGHER THAN TODAYS ON
FRIDAY AS WARMER AIR ADVECTS NORTHWARD THANKS TO THE SOUTHERLY
FLOW.

THAT UPPER LOW PUSHES INTO THE CENTRAL ROCKIES FOR THE START OF
THE WEEKEND. ITS INFLUENCE WILL CONTINUE TO PRODUCE INCREASING
PRECIPITATABLE WATERS ACROSS OUR FORECAST AREA. THUS THE
WIDESPREAD SHOWERS AND SOME THUNDERSTORMS WE ARE ADVERTISING FOR
SATURDAY AND SATURDAY NIGHT LOOKS ON TRACK. WEAK WIND FIELDS
SHOULD NOT SUPPORT ANY ORGANIZED SEVERE THREAT...THOUGH AS LAST
WEEK INDICATED...AN ISOLATED STORM WITH LARGER HAIL CANNOT BE
COMPLETELY RULED OUT. BT

.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...

OVERALL EXTENDED FORECAST APPEARS IN GOOD SHAPE...WITH BROAD
UPPER LEVEL TROF IN CONTROL OVER THE REGION THROUGHOUT THE
MAJORITY OF THE PERIOD. ONLY SMALL ADJUSTMENTS WERE MADE TO CLEAN
UP BORDERS AND CONTINUE TO SLOW TREND TEMPERATURES UPWARD TOWARD
NORMAL THROUGH THE PERIOD.

THE REGION CONTINUES TO BE IMPACTED BY NORTHERN PORTION OF A
STRETCHED OUT UPPER LOW INTO NORTHEAST WYOMING AS IT MOVES INTO
THE DAKOTAS ON SUNDAY. PERSISTENT EAST TO SOUTHEAST SURFACE FLOW
WILL SUPPORT PWATS INTO THE ONE INCH RANGE IN SOUTHEAST MONTANA.
DEEP MOISTURE AVAILABILITY SHOULD ALLOW FOR A GOOD CHANCE FOR
SHOWERS...ESPECIALLY EAST OF BILLINGS. ATMOSPHERE DOES NOT APPEAR
VERY UNSTABLE...SO EXPECT LESS CHANCE OF THUNDER. IMPACTS TO THE
EAST WILL SLOWLY DECREASE THOUGHT MONDAY.

THERE IS SOME INDICATION OF A SHORT PERIOD OF SHORTWAVE RIDGING
ACROSS THE REGION MONDAY NIGHT...AHEAD OF THE NEXT SYSTEM. THIS
WILL BRING A BREAK IN PRECIP OVERNIGHT...BUT TIMING OF THE NEXT
SYSTEM SHOULD KEEP SOME CLOUD COVER IN PLACE AS MOISTURE CONTINUES
TO FLOW INTO THE WESTERN MOUNTAINS.

THE NEXT UPPER LEVEL LOW PRESSURE SYSTEM WILL DROP INTO THE REGION
FROM BRITISH COLUMBIA ON TUESDAY OR WEDNESDAY DEPENDING ON WHICH
MODEL YOU FAVOR. THE EC IS CURRENTLY MUCH FASTER BRINGING THE
SYSTEM INTO THE REGION...AND KEEPING IT OVER THE REGION UNTIL
THURSDAY MORNING. THE GFS HOLD THE LOW TO THE WEST UNTIL
WEDNESDAY...BUT KEEPS IT OVER THE REGION THROUGH THE END OF THE
PERIOD. HAVE GOING POPS INTACT...AS GFS HAS MADE SIGNIFICANT
CHANGE THIS RUN...BUT WILL BE WORTH FURTHER ATTENTION ON LATER
SHIFT. AAG

&&

.AVIATION...

EXPECTED CONTINUED MOUNTAIN SHOWER POTENTIAL TODAY AND
TONIGHT...AS AS A WEAK DISTURBANCE APPROACHES FROM SOUTHERN IDAHO
AND WESTERN MONTANA. SHOWERS WILL BE PRIMARILY CONFINED TO HIGHER
TERRAIN...BUT MAY IMPACT LIVINGSTON AND THE PARADISE VALLEY.
LOCALIZED MVFR CONDITIONS ARE POSSIBLE IN HEAVIER PRECIP. AT LEAST
OCCASIONAL MOUNTAIN OBSCURATION IS EXPECTED THROUGH THE REMAINDER
OF TODAY AND TONIGHT. SHOWERS WILL SPREAD ACROSS THE REGION ON
FRIDAY AFTERNOON...WITH LOCAL MVFR CONDITIONS POSSIBLE IN HEAVIER
PRECIP. AAG
&&

.PRELIMINARY POINT TEMP/POPS...

    FRI     SAT     SUN     MON     TUE     WED     THU
-----------------------------------------------------------
BIL 044/071 046/064 046/063 045/070 048/070 048/072 047/068
    03/T    23/T    23/T    32/T    23/T    33/T    33/T
LVM 040/067 044/060 042/061 039/066 043/066 044/067 041/066
    24/T    35/T    43/T    33/T    34/T    44/T    43/T
HDN 044/073 045/066 046/064 045/072 047/073 048/075 047/071
    03/T    23/T    33/T    32/T    23/T    33/T    33/T
MLS 045/073 046/065 046/064 047/069 046/072 049/073 048/069
    01/B    12/T    34/T    43/T    22/T    23/T    33/T
4BQ 044/068 043/062 046/060 045/068 045/072 048/073 048/069
    02/T    25/T    36/T    43/T    23/T    33/T    34/T
BHK 041/069 042/060 044/061 044/065 043/069 046/069 045/066
    01/N    25/T    46/T    55/T    33/T    33/T    33/T
SHR 041/064 041/060 043/058 041/068 043/069 044/070 045/067
    13/T    25/T    44/T    32/T    24/T    43/T    33/T

&&

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

&&

$$
WEATHER.GOV/BILLINGS



000
FXUS65 KBYZ 212102
AFDBYZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
302 PM MDT THU MAY 21 2015

.SHORT TERM...VALID FOR FRI AND SAT...

SOMEWHAT BENIGN FLOW OVER THE REGION TODAY AS UPPER LOW OFF
CALIFORNIA COAST TRACKS INTO SOUTHERN CALIFORNIA BY EVENING.
WE HAVE SOME MOISTURE THAT HAS ADVECTED INTO WESTERN MONTANA
WHILE THE EAST REMAINS GENERALLY DRY. SO ISOLATED TO SCATTERED
SHOWERS AND MAYBE SOME THUNDER IS EXPECTED THROUGH THE
EVENING...WITH A BIT LINGERING OVERNIGHT. FLOW IS WEAK SO WE DONT
EXPECT THOSE SHOWERS TO MAKE MUCH HEADWAY INTO THE PLAINS.
SOUTHERLY FLOW AND MAYBE AN INCREASE IN HIGH CLOUDS TONIGHT SO I
DO NOT THINK WE WILL GET QUITE AS CHILLY AS WE HAVE BEEN RECENTLY.

FRIDAY/FRIDAY NIGHT...UPPER LOW TRACKS INTO THE DESERT SOUTHWEST
WITH A PIECE OF ENERGY EJECTING OUT AHEAD OF IT IN THE SOUTH TO
NORTH FLOW ALOFT. THIS WILL PUSH INTO WYOMING BY AFTERNOON AND
SPREAD SOME SHOWERS AND PERHAPS SOME THUNDERSTORMS INTO OUR
FORECAST AREA. I LEFT THE HIGHEST POPS OVER THE HIGH COUNTRY TO
THE WEST...REDUCED THE POPS A BIT FOR THE NORTH CENTRAL ZONES
NORTH OF I-94 BASED ON CURRENT PROGGS TRACKING THIS SHORT WAVE
ENERGY. LOOK FOR TEMPS EQUAL TO OR A LITTLE HIGHER THAN TODAYS ON
FRIDAY AS WARMER AIR ADVECTS NORTHWARD THANKS TO THE SOUTHERLY
FLOW.

THAT UPPER LOW PUSHES INTO THE CENTRAL ROCKIES FOR THE START OF
THE WEEKEND. ITS INFLUENCE WILL CONTINUE TO PRODUCE INCREASING
PRECIPITATABLE WATERS ACROSS OUR FORECAST AREA. THUS THE
WIDESPREAD SHOWERS AND SOME THUNDERSTORMS WE ARE ADVERTISING FOR
SATURDAY AND SATURDAY NIGHT LOOKS ON TRACK. WEAK WIND FIELDS
SHOULD NOT SUPPORT ANY ORGANIZED SEVERE THREAT...THOUGH AS LAST
WEEK INDICATED...AN ISOLATED STORM WITH LARGER HAIL CANNOT BE
COMPLETELY RULED OUT. BT

.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...

OVERALL EXTENDED FORECAST APPEARS IN GOOD SHAPE...WITH BROAD
UPPER LEVEL TROF IN CONTROL OVER THE REGION THROUGHOUT THE
MAJORITY OF THE PERIOD. ONLY SMALL ADJUSTMENTS WERE MADE TO CLEAN
UP BORDERS AND CONTINUE TO SLOW TREND TEMPERATURES UPWARD TOWARD
NORMAL THROUGH THE PERIOD.

THE REGION CONTINUES TO BE IMPACTED BY NORTHERN PORTION OF A
STRETCHED OUT UPPER LOW INTO NORTHEAST WYOMING AS IT MOVES INTO
THE DAKOTAS ON SUNDAY. PERSISTENT EAST TO SOUTHEAST SURFACE FLOW
WILL SUPPORT PWATS INTO THE ONE INCH RANGE IN SOUTHEAST MONTANA.
DEEP MOISTURE AVAILABILITY SHOULD ALLOW FOR A GOOD CHANCE FOR
SHOWERS...ESPECIALLY EAST OF BILLINGS. ATMOSPHERE DOES NOT APPEAR
VERY UNSTABLE...SO EXPECT LESS CHANCE OF THUNDER. IMPACTS TO THE
EAST WILL SLOWLY DECREASE THOUGHT MONDAY.

THERE IS SOME INDICATION OF A SHORT PERIOD OF SHORTWAVE RIDGING
ACROSS THE REGION MONDAY NIGHT...AHEAD OF THE NEXT SYSTEM. THIS
WILL BRING A BREAK IN PRECIP OVERNIGHT...BUT TIMING OF THE NEXT
SYSTEM SHOULD KEEP SOME CLOUD COVER IN PLACE AS MOISTURE CONTINUES
TO FLOW INTO THE WESTERN MOUNTAINS.

THE NEXT UPPER LEVEL LOW PRESSURE SYSTEM WILL DROP INTO THE REGION
FROM BRITISH COLUMBIA ON TUESDAY OR WEDNESDAY DEPENDING ON WHICH
MODEL YOU FAVOR. THE EC IS CURRENTLY MUCH FASTER BRINGING THE
SYSTEM INTO THE REGION...AND KEEPING IT OVER THE REGION UNTIL
THURSDAY MORNING. THE GFS HOLD THE LOW TO THE WEST UNTIL
WEDNESDAY...BUT KEEPS IT OVER THE REGION THROUGH THE END OF THE
PERIOD. HAVE GOING POPS INTACT...AS GFS HAS MADE SIGNIFICANT
CHANGE THIS RUN...BUT WILL BE WORTH FURTHER ATTENTION ON LATER
SHIFT. AAG

&&

.AVIATION...

EXPECTED CONTINUED MOUNTAIN SHOWER POTENTIAL TODAY AND
TONIGHT...AS AS A WEAK DISTURBANCE APPROACHES FROM SOUTHERN IDAHO
AND WESTERN MONTANA. SHOWERS WILL BE PRIMARILY CONFINED TO HIGHER
TERRAIN...BUT MAY IMPACT LIVINGSTON AND THE PARADISE VALLEY.
LOCALIZED MVFR CONDITIONS ARE POSSIBLE IN HEAVIER PRECIP. AT LEAST
OCCASIONAL MOUNTAIN OBSCURATION IS EXPECTED THROUGH THE REMAINDER
OF TODAY AND TONIGHT. SHOWERS WILL SPREAD ACROSS THE REGION ON
FRIDAY AFTERNOON...WITH LOCAL MVFR CONDITIONS POSSIBLE IN HEAVIER
PRECIP. AAG
&&

.PRELIMINARY POINT TEMP/POPS...

    FRI     SAT     SUN     MON     TUE     WED     THU
-----------------------------------------------------------
BIL 044/071 046/064 046/063 045/070 048/070 048/072 047/068
    03/T    23/T    23/T    32/T    23/T    33/T    33/T
LVM 040/067 044/060 042/061 039/066 043/066 044/067 041/066
    24/T    35/T    43/T    33/T    34/T    44/T    43/T
HDN 044/073 045/066 046/064 045/072 047/073 048/075 047/071
    03/T    23/T    33/T    32/T    23/T    33/T    33/T
MLS 045/073 046/065 046/064 047/069 046/072 049/073 048/069
    01/B    12/T    34/T    43/T    22/T    23/T    33/T
4BQ 044/068 043/062 046/060 045/068 045/072 048/073 048/069
    02/T    25/T    36/T    43/T    23/T    33/T    34/T
BHK 041/069 042/060 044/061 044/065 043/069 046/069 045/066
    01/N    25/T    46/T    55/T    33/T    33/T    33/T
SHR 041/064 041/060 043/058 041/068 043/069 044/070 045/067
    13/T    25/T    44/T    32/T    24/T    43/T    33/T

&&

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

&&

$$
WEATHER.GOV/BILLINGS



000
FXUS65 KBYZ 212102
AFDBYZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
302 PM MDT THU MAY 21 2015

.SHORT TERM...VALID FOR FRI AND SAT...

SOMEWHAT BENIGN FLOW OVER THE REGION TODAY AS UPPER LOW OFF
CALIFORNIA COAST TRACKS INTO SOUTHERN CALIFORNIA BY EVENING.
WE HAVE SOME MOISTURE THAT HAS ADVECTED INTO WESTERN MONTANA
WHILE THE EAST REMAINS GENERALLY DRY. SO ISOLATED TO SCATTERED
SHOWERS AND MAYBE SOME THUNDER IS EXPECTED THROUGH THE
EVENING...WITH A BIT LINGERING OVERNIGHT. FLOW IS WEAK SO WE DONT
EXPECT THOSE SHOWERS TO MAKE MUCH HEADWAY INTO THE PLAINS.
SOUTHERLY FLOW AND MAYBE AN INCREASE IN HIGH CLOUDS TONIGHT SO I
DO NOT THINK WE WILL GET QUITE AS CHILLY AS WE HAVE BEEN RECENTLY.

FRIDAY/FRIDAY NIGHT...UPPER LOW TRACKS INTO THE DESERT SOUTHWEST
WITH A PIECE OF ENERGY EJECTING OUT AHEAD OF IT IN THE SOUTH TO
NORTH FLOW ALOFT. THIS WILL PUSH INTO WYOMING BY AFTERNOON AND
SPREAD SOME SHOWERS AND PERHAPS SOME THUNDERSTORMS INTO OUR
FORECAST AREA. I LEFT THE HIGHEST POPS OVER THE HIGH COUNTRY TO
THE WEST...REDUCED THE POPS A BIT FOR THE NORTH CENTRAL ZONES
NORTH OF I-94 BASED ON CURRENT PROGGS TRACKING THIS SHORT WAVE
ENERGY. LOOK FOR TEMPS EQUAL TO OR A LITTLE HIGHER THAN TODAYS ON
FRIDAY AS WARMER AIR ADVECTS NORTHWARD THANKS TO THE SOUTHERLY
FLOW.

THAT UPPER LOW PUSHES INTO THE CENTRAL ROCKIES FOR THE START OF
THE WEEKEND. ITS INFLUENCE WILL CONTINUE TO PRODUCE INCREASING
PRECIPITATABLE WATERS ACROSS OUR FORECAST AREA. THUS THE
WIDESPREAD SHOWERS AND SOME THUNDERSTORMS WE ARE ADVERTISING FOR
SATURDAY AND SATURDAY NIGHT LOOKS ON TRACK. WEAK WIND FIELDS
SHOULD NOT SUPPORT ANY ORGANIZED SEVERE THREAT...THOUGH AS LAST
WEEK INDICATED...AN ISOLATED STORM WITH LARGER HAIL CANNOT BE
COMPLETELY RULED OUT. BT

.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...

OVERALL EXTENDED FORECAST APPEARS IN GOOD SHAPE...WITH BROAD
UPPER LEVEL TROF IN CONTROL OVER THE REGION THROUGHOUT THE
MAJORITY OF THE PERIOD. ONLY SMALL ADJUSTMENTS WERE MADE TO CLEAN
UP BORDERS AND CONTINUE TO SLOW TREND TEMPERATURES UPWARD TOWARD
NORMAL THROUGH THE PERIOD.

THE REGION CONTINUES TO BE IMPACTED BY NORTHERN PORTION OF A
STRETCHED OUT UPPER LOW INTO NORTHEAST WYOMING AS IT MOVES INTO
THE DAKOTAS ON SUNDAY. PERSISTENT EAST TO SOUTHEAST SURFACE FLOW
WILL SUPPORT PWATS INTO THE ONE INCH RANGE IN SOUTHEAST MONTANA.
DEEP MOISTURE AVAILABILITY SHOULD ALLOW FOR A GOOD CHANCE FOR
SHOWERS...ESPECIALLY EAST OF BILLINGS. ATMOSPHERE DOES NOT APPEAR
VERY UNSTABLE...SO EXPECT LESS CHANCE OF THUNDER. IMPACTS TO THE
EAST WILL SLOWLY DECREASE THOUGHT MONDAY.

THERE IS SOME INDICATION OF A SHORT PERIOD OF SHORTWAVE RIDGING
ACROSS THE REGION MONDAY NIGHT...AHEAD OF THE NEXT SYSTEM. THIS
WILL BRING A BREAK IN PRECIP OVERNIGHT...BUT TIMING OF THE NEXT
SYSTEM SHOULD KEEP SOME CLOUD COVER IN PLACE AS MOISTURE CONTINUES
TO FLOW INTO THE WESTERN MOUNTAINS.

THE NEXT UPPER LEVEL LOW PRESSURE SYSTEM WILL DROP INTO THE REGION
FROM BRITISH COLUMBIA ON TUESDAY OR WEDNESDAY DEPENDING ON WHICH
MODEL YOU FAVOR. THE EC IS CURRENTLY MUCH FASTER BRINGING THE
SYSTEM INTO THE REGION...AND KEEPING IT OVER THE REGION UNTIL
THURSDAY MORNING. THE GFS HOLD THE LOW TO THE WEST UNTIL
WEDNESDAY...BUT KEEPS IT OVER THE REGION THROUGH THE END OF THE
PERIOD. HAVE GOING POPS INTACT...AS GFS HAS MADE SIGNIFICANT
CHANGE THIS RUN...BUT WILL BE WORTH FURTHER ATTENTION ON LATER
SHIFT. AAG

&&

.AVIATION...

EXPECTED CONTINUED MOUNTAIN SHOWER POTENTIAL TODAY AND
TONIGHT...AS AS A WEAK DISTURBANCE APPROACHES FROM SOUTHERN IDAHO
AND WESTERN MONTANA. SHOWERS WILL BE PRIMARILY CONFINED TO HIGHER
TERRAIN...BUT MAY IMPACT LIVINGSTON AND THE PARADISE VALLEY.
LOCALIZED MVFR CONDITIONS ARE POSSIBLE IN HEAVIER PRECIP. AT LEAST
OCCASIONAL MOUNTAIN OBSCURATION IS EXPECTED THROUGH THE REMAINDER
OF TODAY AND TONIGHT. SHOWERS WILL SPREAD ACROSS THE REGION ON
FRIDAY AFTERNOON...WITH LOCAL MVFR CONDITIONS POSSIBLE IN HEAVIER
PRECIP. AAG
&&

.PRELIMINARY POINT TEMP/POPS...

    FRI     SAT     SUN     MON     TUE     WED     THU
-----------------------------------------------------------
BIL 044/071 046/064 046/063 045/070 048/070 048/072 047/068
    03/T    23/T    23/T    32/T    23/T    33/T    33/T
LVM 040/067 044/060 042/061 039/066 043/066 044/067 041/066
    24/T    35/T    43/T    33/T    34/T    44/T    43/T
HDN 044/073 045/066 046/064 045/072 047/073 048/075 047/071
    03/T    23/T    33/T    32/T    23/T    33/T    33/T
MLS 045/073 046/065 046/064 047/069 046/072 049/073 048/069
    01/B    12/T    34/T    43/T    22/T    23/T    33/T
4BQ 044/068 043/062 046/060 045/068 045/072 048/073 048/069
    02/T    25/T    36/T    43/T    23/T    33/T    34/T
BHK 041/069 042/060 044/061 044/065 043/069 046/069 045/066
    01/N    25/T    46/T    55/T    33/T    33/T    33/T
SHR 041/064 041/060 043/058 041/068 043/069 044/070 045/067
    13/T    25/T    44/T    32/T    24/T    43/T    33/T

&&

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

&&

$$
WEATHER.GOV/BILLINGS



000
FXUS65 KTFX 212054
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
254 PM MDT THU MAY 21 2015

.DISCUSSION...

TONIGHT THROUGH SATURDAY...RELATIVELY LIGHT UPPER LEVEL FLOW FROM
THE SOUTHEAST WILL CONTINUE OVERNIGHT BUT IS EXPECTED TO SHIFT
EAST-NORTHEAST AND INCREASE BY SATURDAY. SCATTERED TO NUMEROUS
SHOWERS AND A FEW THUNDERSTORMS CAN BE EXPECTED ACROSS SOUTHWEST
MONTANA THIS AFTERNOON AND EVENING BEFORE TAPERING OFF TO ISOLATED
SHOWERS OVERNIGHT. ISOLATED CONVECTION COULD REACH SOUTHERN PORTIONS
OF CENTRAL MONTANA THIS AFTERNOON AND EVENING AS WELL. HOWEVER,
FROM FRIDAY EVENING THROUGH SATURDAY AFTERNOON SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS SPREAD ACROSS CENTRAL AND NORTH
CENTRAL MONTANA AS WELL. AS HAS BEEN MENTIONED OVER THE LAST FEW
DAYS, I AM NOT EXPECTED ANY SEVERE WEATHER AS CAPE AND SHEAR
REMAIN RELATIVELY WEAK. MPJ

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.AVIATION...
UPDATED 1050Z.
VFR CONDITIONS WILL CONTINUE OVER NORTH CENTRAL MT THROUGH THE
PERIOD. OVER SOUTHWEST MT...EXPECT SCATTERED THUNDERSTORMS THIS
AFTERNOON AND INTO THE EVENING HOURS...MAINLY BEFORE 03Z FRIDAY.
GUSTY WINDS TO NEAR 30 KTS ARE POSSIBLE WITH A FEW OF THE STRONGER
THUNDERSTORMS. BRUSDA

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  43  70  46  67 /  10  20  30  40
CTB  37  69  41  68 /   0  10  10  20
HLN  45  72  48  67 /  30  30  30  60
BZN  39  69  42  64 /  30  40  30  50
WEY  32  61  34  58 /  40  50  60  60
DLN  41  66  44  64 /  50  40  30  50
HVR  38  73  43  73 /   0  10  30  20
LWT  41  69  45  64 /   0  40  40  40

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 212054
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
254 PM MDT THU MAY 21 2015

.DISCUSSION...

TONIGHT THROUGH SATURDAY...RELATIVELY LIGHT UPPER LEVEL FLOW FROM
THE SOUTHEAST WILL CONTINUE OVERNIGHT BUT IS EXPECTED TO SHIFT
EAST-NORTHEAST AND INCREASE BY SATURDAY. SCATTERED TO NUMEROUS
SHOWERS AND A FEW THUNDERSTORMS CAN BE EXPECTED ACROSS SOUTHWEST
MONTANA THIS AFTERNOON AND EVENING BEFORE TAPERING OFF TO ISOLATED
SHOWERS OVERNIGHT. ISOLATED CONVECTION COULD REACH SOUTHERN PORTIONS
OF CENTRAL MONTANA THIS AFTERNOON AND EVENING AS WELL. HOWEVER,
FROM FRIDAY EVENING THROUGH SATURDAY AFTERNOON SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS SPREAD ACROSS CENTRAL AND NORTH
CENTRAL MONTANA AS WELL. AS HAS BEEN MENTIONED OVER THE LAST FEW
DAYS, I AM NOT EXPECTED ANY SEVERE WEATHER AS CAPE AND SHEAR
REMAIN RELATIVELY WEAK. MPJ

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.AVIATION...
UPDATED 1050Z.
VFR CONDITIONS WILL CONTINUE OVER NORTH CENTRAL MT THROUGH THE
PERIOD. OVER SOUTHWEST MT...EXPECT SCATTERED THUNDERSTORMS THIS
AFTERNOON AND INTO THE EVENING HOURS...MAINLY BEFORE 03Z FRIDAY.
GUSTY WINDS TO NEAR 30 KTS ARE POSSIBLE WITH A FEW OF THE STRONGER
THUNDERSTORMS. BRUSDA

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  43  70  46  67 /  10  20  30  40
CTB  37  69  41  68 /   0  10  10  20
HLN  45  72  48  67 /  30  30  30  60
BZN  39  69  42  64 /  30  40  30  50
WEY  32  61  34  58 /  40  50  60  60
DLN  41  66  44  64 /  50  40  30  50
HVR  38  73  43  73 /   0  10  30  20
LWT  41  69  45  64 /   0  40  40  40

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS




000
FXUS65 KTFX 212054
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
254 PM MDT THU MAY 21 2015

.DISCUSSION...

TONIGHT THROUGH SATURDAY...RELATIVELY LIGHT UPPER LEVEL FLOW FROM
THE SOUTHEAST WILL CONTINUE OVERNIGHT BUT IS EXPECTED TO SHIFT
EAST-NORTHEAST AND INCREASE BY SATURDAY. SCATTERED TO NUMEROUS
SHOWERS AND A FEW THUNDERSTORMS CAN BE EXPECTED ACROSS SOUTHWEST
MONTANA THIS AFTERNOON AND EVENING BEFORE TAPERING OFF TO ISOLATED
SHOWERS OVERNIGHT. ISOLATED CONVECTION COULD REACH SOUTHERN PORTIONS
OF CENTRAL MONTANA THIS AFTERNOON AND EVENING AS WELL. HOWEVER,
FROM FRIDAY EVENING THROUGH SATURDAY AFTERNOON SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS SPREAD ACROSS CENTRAL AND NORTH
CENTRAL MONTANA AS WELL. AS HAS BEEN MENTIONED OVER THE LAST FEW
DAYS, I AM NOT EXPECTED ANY SEVERE WEATHER AS CAPE AND SHEAR
REMAIN RELATIVELY WEAK. MPJ

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.AVIATION...
UPDATED 1050Z.
VFR CONDITIONS WILL CONTINUE OVER NORTH CENTRAL MT THROUGH THE
PERIOD. OVER SOUTHWEST MT...EXPECT SCATTERED THUNDERSTORMS THIS
AFTERNOON AND INTO THE EVENING HOURS...MAINLY BEFORE 03Z FRIDAY.
GUSTY WINDS TO NEAR 30 KTS ARE POSSIBLE WITH A FEW OF THE STRONGER
THUNDERSTORMS. BRUSDA

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  43  70  46  67 /  10  20  30  40
CTB  37  69  41  68 /   0  10  10  20
HLN  45  72  48  67 /  30  30  30  60
BZN  39  69  42  64 /  30  40  30  50
WEY  32  61  34  58 /  40  50  60  60
DLN  41  66  44  64 /  50  40  30  50
HVR  38  73  43  73 /   0  10  30  20
LWT  41  69  45  64 /   0  40  40  40

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 212054
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
254 PM MDT THU MAY 21 2015

.DISCUSSION...

TONIGHT THROUGH SATURDAY...RELATIVELY LIGHT UPPER LEVEL FLOW FROM
THE SOUTHEAST WILL CONTINUE OVERNIGHT BUT IS EXPECTED TO SHIFT
EAST-NORTHEAST AND INCREASE BY SATURDAY. SCATTERED TO NUMEROUS
SHOWERS AND A FEW THUNDERSTORMS CAN BE EXPECTED ACROSS SOUTHWEST
MONTANA THIS AFTERNOON AND EVENING BEFORE TAPERING OFF TO ISOLATED
SHOWERS OVERNIGHT. ISOLATED CONVECTION COULD REACH SOUTHERN PORTIONS
OF CENTRAL MONTANA THIS AFTERNOON AND EVENING AS WELL. HOWEVER,
FROM FRIDAY EVENING THROUGH SATURDAY AFTERNOON SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS SPREAD ACROSS CENTRAL AND NORTH
CENTRAL MONTANA AS WELL. AS HAS BEEN MENTIONED OVER THE LAST FEW
DAYS, I AM NOT EXPECTED ANY SEVERE WEATHER AS CAPE AND SHEAR
REMAIN RELATIVELY WEAK. MPJ

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.AVIATION...
UPDATED 1050Z.
VFR CONDITIONS WILL CONTINUE OVER NORTH CENTRAL MT THROUGH THE
PERIOD. OVER SOUTHWEST MT...EXPECT SCATTERED THUNDERSTORMS THIS
AFTERNOON AND INTO THE EVENING HOURS...MAINLY BEFORE 03Z FRIDAY.
GUSTY WINDS TO NEAR 30 KTS ARE POSSIBLE WITH A FEW OF THE STRONGER
THUNDERSTORMS. BRUSDA

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  43  70  46  67 /  10  20  30  40
CTB  37  69  41  68 /   0  10  10  20
HLN  45  72  48  67 /  30  30  30  60
BZN  39  69  42  64 /  30  40  30  50
WEY  32  61  34  58 /  40  50  60  60
DLN  41  66  44  64 /  50  40  30  50
HVR  38  73  43  73 /   0  10  30  20
LWT  41  69  45  64 /   0  40  40  40

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS




000
FXUS65 KMSO 212051
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
251 PM MDT THU MAY 21 2015

.DISCUSSION...Scattered showers and isolated thunderstorms have
developed over parts of the Northern Rockies, especially in
central Idaho and west central Montana from the I-90 corridor
south. This convection is slow moving, so stronger storms that
develop could produce some brief local heavy rain and gusty
winds, mainly over the higher terrain.  Expect activity to end
later this evening around sunset (9 pm or so). Northwest Montana
will largely remain dry through this evening.

Expect very similar conditions for Friday through Sunday, aka
development of afternoon showers and isolated thunderstorms
dissipating by mid evening. Confidence is pretty good that
convection will develop in similar areas, central Idaho, west
central and southwest Montana, eg the I-90 corridor south.
Northwest Montana will continue to experience light to moderate
sustained northeast winds the next few days. Drier air will push
across the divide tonight in the Glacier NP region and set itself
up over far Northwest Montana for Friday and Saturday. This will
inhibit showers from developing.

An upper level low pressure system will enter the Pacific
northwest late Sunday into Monday and Tuesday. This low will
provide a little more dynamic or synoptic support for the
development of showers and thunderstorms. The change with this
system is it`s likely the coverage of precipitation will
encompass all of the Northern Rockies, which would be good news
for Northwest Montana which really needs moisture. However
confidence is still low for exact placement of the greatest precip
coverage, mainly due to the fact the models have not done a very
good job at all this spring placing these closed lows several days
out. And with this particular system, forecast solutions have
varied significantly.

The rest of next week continues to be unsettled with a potential
for scattered showers each afternoon.

Expect slightly above normal temperatures with above normal low
temperatures at night.


&&

.AVIATION...Showers and thunderstorms have developed this
afternoon across north central Idaho into southwest Montana.
Convection is expected to generally remain along and south of a
line from KMLP to KMSO to KHLN. This activity is expected to
continue into mid evening, before dissipating around sunset. The
main threats with thunderstorms will be lightning, brief heavy
rain limiting visibility and gusty winds. KBTM and KSMN are the
most likely airfields to be impacted by thunderstorms. KMSO has a
slight possibility but will be at the far northward extent of
storms. Across northwest Montana, convection is not expected to
develop. However, northeast to east winds are expected to increase
slightly this evening. Another round of thunderstorms is possible
across the region on Friday afternoon, in generally the same
locations.



&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

$$



000
FXUS65 KMSO 212051
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
251 PM MDT THU MAY 21 2015

.DISCUSSION...Scattered showers and isolated thunderstorms have
developed over parts of the Northern Rockies, especially in
central Idaho and west central Montana from the I-90 corridor
south. This convection is slow moving, so stronger storms that
develop could produce some brief local heavy rain and gusty
winds, mainly over the higher terrain.  Expect activity to end
later this evening around sunset (9 pm or so). Northwest Montana
will largely remain dry through this evening.

Expect very similar conditions for Friday through Sunday, aka
development of afternoon showers and isolated thunderstorms
dissipating by mid evening. Confidence is pretty good that
convection will develop in similar areas, central Idaho, west
central and southwest Montana, eg the I-90 corridor south.
Northwest Montana will continue to experience light to moderate
sustained northeast winds the next few days. Drier air will push
across the divide tonight in the Glacier NP region and set itself
up over far Northwest Montana for Friday and Saturday. This will
inhibit showers from developing.

An upper level low pressure system will enter the Pacific
northwest late Sunday into Monday and Tuesday. This low will
provide a little more dynamic or synoptic support for the
development of showers and thunderstorms. The change with this
system is it`s likely the coverage of precipitation will
encompass all of the Northern Rockies, which would be good news
for Northwest Montana which really needs moisture. However
confidence is still low for exact placement of the greatest precip
coverage, mainly due to the fact the models have not done a very
good job at all this spring placing these closed lows several days
out. And with this particular system, forecast solutions have
varied significantly.

The rest of next week continues to be unsettled with a potential
for scattered showers each afternoon.

Expect slightly above normal temperatures with above normal low
temperatures at night.


&&

.AVIATION...Showers and thunderstorms have developed this
afternoon across north central Idaho into southwest Montana.
Convection is expected to generally remain along and south of a
line from KMLP to KMSO to KHLN. This activity is expected to
continue into mid evening, before dissipating around sunset. The
main threats with thunderstorms will be lightning, brief heavy
rain limiting visibility and gusty winds. KBTM and KSMN are the
most likely airfields to be impacted by thunderstorms. KMSO has a
slight possibility but will be at the far northward extent of
storms. Across northwest Montana, convection is not expected to
develop. However, northeast to east winds are expected to increase
slightly this evening. Another round of thunderstorms is possible
across the region on Friday afternoon, in generally the same
locations.



&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

$$




000
FXUS65 KMSO 212051
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
251 PM MDT THU MAY 21 2015

.DISCUSSION...Scattered showers and isolated thunderstorms have
developed over parts of the Northern Rockies, especially in
central Idaho and west central Montana from the I-90 corridor
south. This convection is slow moving, so stronger storms that
develop could produce some brief local heavy rain and gusty
winds, mainly over the higher terrain.  Expect activity to end
later this evening around sunset (9 pm or so). Northwest Montana
will largely remain dry through this evening.

Expect very similar conditions for Friday through Sunday, aka
development of afternoon showers and isolated thunderstorms
dissipating by mid evening. Confidence is pretty good that
convection will develop in similar areas, central Idaho, west
central and southwest Montana, eg the I-90 corridor south.
Northwest Montana will continue to experience light to moderate
sustained northeast winds the next few days. Drier air will push
across the divide tonight in the Glacier NP region and set itself
up over far Northwest Montana for Friday and Saturday. This will
inhibit showers from developing.

An upper level low pressure system will enter the Pacific
northwest late Sunday into Monday and Tuesday. This low will
provide a little more dynamic or synoptic support for the
development of showers and thunderstorms. The change with this
system is it`s likely the coverage of precipitation will
encompass all of the Northern Rockies, which would be good news
for Northwest Montana which really needs moisture. However
confidence is still low for exact placement of the greatest precip
coverage, mainly due to the fact the models have not done a very
good job at all this spring placing these closed lows several days
out. And with this particular system, forecast solutions have
varied significantly.

The rest of next week continues to be unsettled with a potential
for scattered showers each afternoon.

Expect slightly above normal temperatures with above normal low
temperatures at night.


&&

.AVIATION...Showers and thunderstorms have developed this
afternoon across north central Idaho into southwest Montana.
Convection is expected to generally remain along and south of a
line from KMLP to KMSO to KHLN. This activity is expected to
continue into mid evening, before dissipating around sunset. The
main threats with thunderstorms will be lightning, brief heavy
rain limiting visibility and gusty winds. KBTM and KSMN are the
most likely airfields to be impacted by thunderstorms. KMSO has a
slight possibility but will be at the far northward extent of
storms. Across northwest Montana, convection is not expected to
develop. However, northeast to east winds are expected to increase
slightly this evening. Another round of thunderstorms is possible
across the region on Friday afternoon, in generally the same
locations.



&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

$$




000
FXUS65 KMSO 212051
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
251 PM MDT THU MAY 21 2015

.DISCUSSION...Scattered showers and isolated thunderstorms have
developed over parts of the Northern Rockies, especially in
central Idaho and west central Montana from the I-90 corridor
south. This convection is slow moving, so stronger storms that
develop could produce some brief local heavy rain and gusty
winds, mainly over the higher terrain.  Expect activity to end
later this evening around sunset (9 pm or so). Northwest Montana
will largely remain dry through this evening.

Expect very similar conditions for Friday through Sunday, aka
development of afternoon showers and isolated thunderstorms
dissipating by mid evening. Confidence is pretty good that
convection will develop in similar areas, central Idaho, west
central and southwest Montana, eg the I-90 corridor south.
Northwest Montana will continue to experience light to moderate
sustained northeast winds the next few days. Drier air will push
across the divide tonight in the Glacier NP region and set itself
up over far Northwest Montana for Friday and Saturday. This will
inhibit showers from developing.

An upper level low pressure system will enter the Pacific
northwest late Sunday into Monday and Tuesday. This low will
provide a little more dynamic or synoptic support for the
development of showers and thunderstorms. The change with this
system is it`s likely the coverage of precipitation will
encompass all of the Northern Rockies, which would be good news
for Northwest Montana which really needs moisture. However
confidence is still low for exact placement of the greatest precip
coverage, mainly due to the fact the models have not done a very
good job at all this spring placing these closed lows several days
out. And with this particular system, forecast solutions have
varied significantly.

The rest of next week continues to be unsettled with a potential
for scattered showers each afternoon.

Expect slightly above normal temperatures with above normal low
temperatures at night.


&&

.AVIATION...Showers and thunderstorms have developed this
afternoon across north central Idaho into southwest Montana.
Convection is expected to generally remain along and south of a
line from KMLP to KMSO to KHLN. This activity is expected to
continue into mid evening, before dissipating around sunset. The
main threats with thunderstorms will be lightning, brief heavy
rain limiting visibility and gusty winds. KBTM and KSMN are the
most likely airfields to be impacted by thunderstorms. KMSO has a
slight possibility but will be at the far northward extent of
storms. Across northwest Montana, convection is not expected to
develop. However, northeast to east winds are expected to increase
slightly this evening. Another round of thunderstorms is possible
across the region on Friday afternoon, in generally the same
locations.



&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

$$



000
FXUS65 KGGW 212037
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
237 PM MDT THU MAY 21 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SATURDAY...

SYNOPTIC SET UP... A CLOSED LOW SETS OVER THE QUEBEC/ONTARIO
BORDER WITH A LARGE TROUGH SURROUNDING IT AND EXTENDING ITS
INFLUENCE INTO THE EASTERN TWO THIRDS OF THE CONUS. A NARROW HIGH
AMPLITUDE RIDGE HAS DEVELOPED OVER THE WESTERN THIRD OF THE US AND
CANADA. NORTHEAST MONTANA STANDS BETWEEN THESE TWO FEATURES UNDER
NORTHERN TO NORTHWESTERN FLOW ALOFT. FARTHER WEST ANOTHER MORE
NARROW TROUGH EXTENDS FROM OFF THE COASTS OF BRITISH COLUMBIA TO
SOUTHERN CALIFORNIA.

TONIGHT... DRY NORTHERN FLOW ALOFT AND SURFACE HIGH PRESSURE ACROSS
THE REGION WILL ACT TO KEEP NORTHEASTERN MONTANA DRY AND CLEAR.

FRIDAY THROUGH FRIDAY NIGHT... WITH ATMOSPHERE SLOWLY MODIFYING
WARMER AT THE SURFACE AND COOLER MID LEVEL AIR ENTER IN THE REGION
FROM THE SOUTHEAST SOME INSTABILITY IS EXPECTED TO DEVELOPED
FRIDAY AFTERNOON. AREAS OF OROGRAPHIC LIFT SUCH AS THE CENTRAL
MONTANA MOUNTAINS ARE WHERE THIS INSTABILITY SHOULD INITIALIZE.
SOME SPILL OVER INT THE AFTERNOON AND EVENINGS HOURS IS POSSIBLE
FOR PETROLEUM... PHILLIPS... AND WESTERN GARFIELD COUNTY.

STRONG SURFACE WINDS WILL ALSO ALLOW FOR A LAKE WIND ADVISORY TO
BE IN AFFECT DURING THE AFTERNOON HOURS.

SATURDAY... A CHANCE FOR MOUNTAIN INSTABILITY STILL EXISTS BUT
LESSENS. FOCUS SHIFTS TO THE SOUTHEASTERN CWA WITH A COLD AIR
POCKET DEVELOPING OVER THE DAKOTAS AND EASTERN MT. THIS WILL
ALLOW A LIFT ZONE TO FORM AND SHOWERS TO SPILL INTO THE YELLOWSTONE
VALLEY THAT AFTERNOON AND EVENING. GAH


.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
12Z MODELS REMAINED INCONSISTENT WITH PRECIP PLACEMENT LATER THIS
WEEKEND. THIS TIME THE GFS DRAGGED PRECIP INTO THE CWA FROM THE
SOUTHEAST AND WAS SLOWER TO PUSH IT OUT OF HERE EARLY NEXT WEEK.
MAINLY TRIMMED POPS AS THE PRECIP AREA HAS TRENDED EAST A BIT.
INSTABILITY WITH THE NEIGHBORING UPPER LOW WILL LEAD TO SLIGHT
CHANCE OF SHOWERS. TFJ


PREVIOUS DISCUSSION...
SATURDAY NIGHT AND SUNDAY FEATURES A BROAD UPPER TROUGH OVER THE
WEST AND AN UPPER RIDGE TO EAST OF NORTHEAST MONTANA. THE TROUGH
WILL LIFT NORTH INTO MONTANA AND NORTH DAKOTA BY MONDAY. THEN...THE
FLOW PATTERN ALOFT OVER MONTANA WILL BE WEAK...VARIABLE AND UN-
FOCUSED MONDAY AND TUESDAY. THE SOUTHEAST HALF OF THE FORECAST
AREA HAS A BETTER CHANCE OF SEEING SHOWERS MAYBE THUNDERSTORMS AT
TIMES BETWEEN SATURDAY NIGHT AND MONDAY WHERE THE DEEPER MOISTURE
IS EXPECTED.

MODEL DIFFERENCES SHOW UP TUESDAY AND BEYOND AS GFS HAS A NW FLOW
ALOFT WITH A BACK DOOR COLD FRONT ON WEDNESDAY. ECMWF HAS AN UPPER
TROUGH OVER THE PACIFIC NW ON TUESDAY THAT EVENTUALLY MOVES EAST
ACROSS MONTANA WEDNESDAY AND THURSDAY. WILL MAINTAIN A
CHANCE/SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR NOW.
FORRESTER


&&

.AVIATION...
VFR.

MAINLY CLEAR SKIES TONIGHT AND FRIDAY. SOUTHEAST WINDS AROUND 10
KTS EXCEPT LIGHT AT KSDY. SOUTHEAST WINDS WILL BE STRONGER FRIDAY.
TFJ


&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM 11 AM TO 8 PM MDT FRIDAY FOR FORT PECK
LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN
VALLEY...GARFIELD...MCCONE...PETROLEUM.


&&

$$

WEATHER.GOV/GLASGOW





000
FXUS65 KGGW 212037
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
237 PM MDT THU MAY 21 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SATURDAY...

SYNOPTIC SET UP... A CLOSED LOW SETS OVER THE QUEBEC/ONTARIO
BORDER WITH A LARGE TROUGH SURROUNDING IT AND EXTENDING ITS
INFLUENCE INTO THE EASTERN TWO THIRDS OF THE CONUS. A NARROW HIGH
AMPLITUDE RIDGE HAS DEVELOPED OVER THE WESTERN THIRD OF THE US AND
CANADA. NORTHEAST MONTANA STANDS BETWEEN THESE TWO FEATURES UNDER
NORTHERN TO NORTHWESTERN FLOW ALOFT. FARTHER WEST ANOTHER MORE
NARROW TROUGH EXTENDS FROM OFF THE COASTS OF BRITISH COLUMBIA TO
SOUTHERN CALIFORNIA.

TONIGHT... DRY NORTHERN FLOW ALOFT AND SURFACE HIGH PRESSURE ACROSS
THE REGION WILL ACT TO KEEP NORTHEASTERN MONTANA DRY AND CLEAR.

FRIDAY THROUGH FRIDAY NIGHT... WITH ATMOSPHERE SLOWLY MODIFYING
WARMER AT THE SURFACE AND COOLER MID LEVEL AIR ENTER IN THE REGION
FROM THE SOUTHEAST SOME INSTABILITY IS EXPECTED TO DEVELOPED
FRIDAY AFTERNOON. AREAS OF OROGRAPHIC LIFT SUCH AS THE CENTRAL
MONTANA MOUNTAINS ARE WHERE THIS INSTABILITY SHOULD INITIALIZE.
SOME SPILL OVER INT THE AFTERNOON AND EVENINGS HOURS IS POSSIBLE
FOR PETROLEUM... PHILLIPS... AND WESTERN GARFIELD COUNTY.

STRONG SURFACE WINDS WILL ALSO ALLOW FOR A LAKE WIND ADVISORY TO
BE IN AFFECT DURING THE AFTERNOON HOURS.

SATURDAY... A CHANCE FOR MOUNTAIN INSTABILITY STILL EXISTS BUT
LESSENS. FOCUS SHIFTS TO THE SOUTHEASTERN CWA WITH A COLD AIR
POCKET DEVELOPING OVER THE DAKOTAS AND EASTERN MT. THIS WILL
ALLOW A LIFT ZONE TO FORM AND SHOWERS TO SPILL INTO THE YELLOWSTONE
VALLEY THAT AFTERNOON AND EVENING. GAH


.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
12Z MODELS REMAINED INCONSISTENT WITH PRECIP PLACEMENT LATER THIS
WEEKEND. THIS TIME THE GFS DRAGGED PRECIP INTO THE CWA FROM THE
SOUTHEAST AND WAS SLOWER TO PUSH IT OUT OF HERE EARLY NEXT WEEK.
MAINLY TRIMMED POPS AS THE PRECIP AREA HAS TRENDED EAST A BIT.
INSTABILITY WITH THE NEIGHBORING UPPER LOW WILL LEAD TO SLIGHT
CHANCE OF SHOWERS. TFJ


PREVIOUS DISCUSSION...
SATURDAY NIGHT AND SUNDAY FEATURES A BROAD UPPER TROUGH OVER THE
WEST AND AN UPPER RIDGE TO EAST OF NORTHEAST MONTANA. THE TROUGH
WILL LIFT NORTH INTO MONTANA AND NORTH DAKOTA BY MONDAY. THEN...THE
FLOW PATTERN ALOFT OVER MONTANA WILL BE WEAK...VARIABLE AND UN-
FOCUSED MONDAY AND TUESDAY. THE SOUTHEAST HALF OF THE FORECAST
AREA HAS A BETTER CHANCE OF SEEING SHOWERS MAYBE THUNDERSTORMS AT
TIMES BETWEEN SATURDAY NIGHT AND MONDAY WHERE THE DEEPER MOISTURE
IS EXPECTED.

MODEL DIFFERENCES SHOW UP TUESDAY AND BEYOND AS GFS HAS A NW FLOW
ALOFT WITH A BACK DOOR COLD FRONT ON WEDNESDAY. ECMWF HAS AN UPPER
TROUGH OVER THE PACIFIC NW ON TUESDAY THAT EVENTUALLY MOVES EAST
ACROSS MONTANA WEDNESDAY AND THURSDAY. WILL MAINTAIN A
CHANCE/SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR NOW.
FORRESTER


&&

.AVIATION...
VFR.

MAINLY CLEAR SKIES TONIGHT AND FRIDAY. SOUTHEAST WINDS AROUND 10
KTS EXCEPT LIGHT AT KSDY. SOUTHEAST WINDS WILL BE STRONGER FRIDAY.
TFJ


&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM 11 AM TO 8 PM MDT FRIDAY FOR FORT PECK
LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN
VALLEY...GARFIELD...MCCONE...PETROLEUM.


&&

$$

WEATHER.GOV/GLASGOW





000
FXUS65 KGGW 212037
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
237 PM MDT THU MAY 21 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SATURDAY...

SYNOPTIC SET UP... A CLOSED LOW SETS OVER THE QUEBEC/ONTARIO
BORDER WITH A LARGE TROUGH SURROUNDING IT AND EXTENDING ITS
INFLUENCE INTO THE EASTERN TWO THIRDS OF THE CONUS. A NARROW HIGH
AMPLITUDE RIDGE HAS DEVELOPED OVER THE WESTERN THIRD OF THE US AND
CANADA. NORTHEAST MONTANA STANDS BETWEEN THESE TWO FEATURES UNDER
NORTHERN TO NORTHWESTERN FLOW ALOFT. FARTHER WEST ANOTHER MORE
NARROW TROUGH EXTENDS FROM OFF THE COASTS OF BRITISH COLUMBIA TO
SOUTHERN CALIFORNIA.

TONIGHT... DRY NORTHERN FLOW ALOFT AND SURFACE HIGH PRESSURE ACROSS
THE REGION WILL ACT TO KEEP NORTHEASTERN MONTANA DRY AND CLEAR.

FRIDAY THROUGH FRIDAY NIGHT... WITH ATMOSPHERE SLOWLY MODIFYING
WARMER AT THE SURFACE AND COOLER MID LEVEL AIR ENTER IN THE REGION
FROM THE SOUTHEAST SOME INSTABILITY IS EXPECTED TO DEVELOPED
FRIDAY AFTERNOON. AREAS OF OROGRAPHIC LIFT SUCH AS THE CENTRAL
MONTANA MOUNTAINS ARE WHERE THIS INSTABILITY SHOULD INITIALIZE.
SOME SPILL OVER INT THE AFTERNOON AND EVENINGS HOURS IS POSSIBLE
FOR PETROLEUM... PHILLIPS... AND WESTERN GARFIELD COUNTY.

STRONG SURFACE WINDS WILL ALSO ALLOW FOR A LAKE WIND ADVISORY TO
BE IN AFFECT DURING THE AFTERNOON HOURS.

SATURDAY... A CHANCE FOR MOUNTAIN INSTABILITY STILL EXISTS BUT
LESSENS. FOCUS SHIFTS TO THE SOUTHEASTERN CWA WITH A COLD AIR
POCKET DEVELOPING OVER THE DAKOTAS AND EASTERN MT. THIS WILL
ALLOW A LIFT ZONE TO FORM AND SHOWERS TO SPILL INTO THE YELLOWSTONE
VALLEY THAT AFTERNOON AND EVENING. GAH


.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
12Z MODELS REMAINED INCONSISTENT WITH PRECIP PLACEMENT LATER THIS
WEEKEND. THIS TIME THE GFS DRAGGED PRECIP INTO THE CWA FROM THE
SOUTHEAST AND WAS SLOWER TO PUSH IT OUT OF HERE EARLY NEXT WEEK.
MAINLY TRIMMED POPS AS THE PRECIP AREA HAS TRENDED EAST A BIT.
INSTABILITY WITH THE NEIGHBORING UPPER LOW WILL LEAD TO SLIGHT
CHANCE OF SHOWERS. TFJ


PREVIOUS DISCUSSION...
SATURDAY NIGHT AND SUNDAY FEATURES A BROAD UPPER TROUGH OVER THE
WEST AND AN UPPER RIDGE TO EAST OF NORTHEAST MONTANA. THE TROUGH
WILL LIFT NORTH INTO MONTANA AND NORTH DAKOTA BY MONDAY. THEN...THE
FLOW PATTERN ALOFT OVER MONTANA WILL BE WEAK...VARIABLE AND UN-
FOCUSED MONDAY AND TUESDAY. THE SOUTHEAST HALF OF THE FORECAST
AREA HAS A BETTER CHANCE OF SEEING SHOWERS MAYBE THUNDERSTORMS AT
TIMES BETWEEN SATURDAY NIGHT AND MONDAY WHERE THE DEEPER MOISTURE
IS EXPECTED.

MODEL DIFFERENCES SHOW UP TUESDAY AND BEYOND AS GFS HAS A NW FLOW
ALOFT WITH A BACK DOOR COLD FRONT ON WEDNESDAY. ECMWF HAS AN UPPER
TROUGH OVER THE PACIFIC NW ON TUESDAY THAT EVENTUALLY MOVES EAST
ACROSS MONTANA WEDNESDAY AND THURSDAY. WILL MAINTAIN A
CHANCE/SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR NOW.
FORRESTER


&&

.AVIATION...
VFR.

MAINLY CLEAR SKIES TONIGHT AND FRIDAY. SOUTHEAST WINDS AROUND 10
KTS EXCEPT LIGHT AT KSDY. SOUTHEAST WINDS WILL BE STRONGER FRIDAY.
TFJ


&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM 11 AM TO 8 PM MDT FRIDAY FOR FORT PECK
LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN
VALLEY...GARFIELD...MCCONE...PETROLEUM.


&&

$$

WEATHER.GOV/GLASGOW





000
FXUS65 KGGW 212037
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
237 PM MDT THU MAY 21 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SATURDAY...

SYNOPTIC SET UP... A CLOSED LOW SETS OVER THE QUEBEC/ONTARIO
BORDER WITH A LARGE TROUGH SURROUNDING IT AND EXTENDING ITS
INFLUENCE INTO THE EASTERN TWO THIRDS OF THE CONUS. A NARROW HIGH
AMPLITUDE RIDGE HAS DEVELOPED OVER THE WESTERN THIRD OF THE US AND
CANADA. NORTHEAST MONTANA STANDS BETWEEN THESE TWO FEATURES UNDER
NORTHERN TO NORTHWESTERN FLOW ALOFT. FARTHER WEST ANOTHER MORE
NARROW TROUGH EXTENDS FROM OFF THE COASTS OF BRITISH COLUMBIA TO
SOUTHERN CALIFORNIA.

TONIGHT... DRY NORTHERN FLOW ALOFT AND SURFACE HIGH PRESSURE ACROSS
THE REGION WILL ACT TO KEEP NORTHEASTERN MONTANA DRY AND CLEAR.

FRIDAY THROUGH FRIDAY NIGHT... WITH ATMOSPHERE SLOWLY MODIFYING
WARMER AT THE SURFACE AND COOLER MID LEVEL AIR ENTER IN THE REGION
FROM THE SOUTHEAST SOME INSTABILITY IS EXPECTED TO DEVELOPED
FRIDAY AFTERNOON. AREAS OF OROGRAPHIC LIFT SUCH AS THE CENTRAL
MONTANA MOUNTAINS ARE WHERE THIS INSTABILITY SHOULD INITIALIZE.
SOME SPILL OVER INT THE AFTERNOON AND EVENINGS HOURS IS POSSIBLE
FOR PETROLEUM... PHILLIPS... AND WESTERN GARFIELD COUNTY.

STRONG SURFACE WINDS WILL ALSO ALLOW FOR A LAKE WIND ADVISORY TO
BE IN AFFECT DURING THE AFTERNOON HOURS.

SATURDAY... A CHANCE FOR MOUNTAIN INSTABILITY STILL EXISTS BUT
LESSENS. FOCUS SHIFTS TO THE SOUTHEASTERN CWA WITH A COLD AIR
POCKET DEVELOPING OVER THE DAKOTAS AND EASTERN MT. THIS WILL
ALLOW A LIFT ZONE TO FORM AND SHOWERS TO SPILL INTO THE YELLOWSTONE
VALLEY THAT AFTERNOON AND EVENING. GAH


.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
12Z MODELS REMAINED INCONSISTENT WITH PRECIP PLACEMENT LATER THIS
WEEKEND. THIS TIME THE GFS DRAGGED PRECIP INTO THE CWA FROM THE
SOUTHEAST AND WAS SLOWER TO PUSH IT OUT OF HERE EARLY NEXT WEEK.
MAINLY TRIMMED POPS AS THE PRECIP AREA HAS TRENDED EAST A BIT.
INSTABILITY WITH THE NEIGHBORING UPPER LOW WILL LEAD TO SLIGHT
CHANCE OF SHOWERS. TFJ


PREVIOUS DISCUSSION...
SATURDAY NIGHT AND SUNDAY FEATURES A BROAD UPPER TROUGH OVER THE
WEST AND AN UPPER RIDGE TO EAST OF NORTHEAST MONTANA. THE TROUGH
WILL LIFT NORTH INTO MONTANA AND NORTH DAKOTA BY MONDAY. THEN...THE
FLOW PATTERN ALOFT OVER MONTANA WILL BE WEAK...VARIABLE AND UN-
FOCUSED MONDAY AND TUESDAY. THE SOUTHEAST HALF OF THE FORECAST
AREA HAS A BETTER CHANCE OF SEEING SHOWERS MAYBE THUNDERSTORMS AT
TIMES BETWEEN SATURDAY NIGHT AND MONDAY WHERE THE DEEPER MOISTURE
IS EXPECTED.

MODEL DIFFERENCES SHOW UP TUESDAY AND BEYOND AS GFS HAS A NW FLOW
ALOFT WITH A BACK DOOR COLD FRONT ON WEDNESDAY. ECMWF HAS AN UPPER
TROUGH OVER THE PACIFIC NW ON TUESDAY THAT EVENTUALLY MOVES EAST
ACROSS MONTANA WEDNESDAY AND THURSDAY. WILL MAINTAIN A
CHANCE/SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR NOW.
FORRESTER


&&

.AVIATION...
VFR.

MAINLY CLEAR SKIES TONIGHT AND FRIDAY. SOUTHEAST WINDS AROUND 10
KTS EXCEPT LIGHT AT KSDY. SOUTHEAST WINDS WILL BE STRONGER FRIDAY.
TFJ


&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM 11 AM TO 8 PM MDT FRIDAY FOR FORT PECK
LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN
VALLEY...GARFIELD...MCCONE...PETROLEUM.


&&

$$

WEATHER.GOV/GLASGOW





000
FXUS65 KGGW 212037
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
237 PM MDT THU MAY 21 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SATURDAY...

SYNOPTIC SET UP... A CLOSED LOW SETS OVER THE QUEBEC/ONTARIO
BORDER WITH A LARGE TROUGH SURROUNDING IT AND EXTENDING ITS
INFLUENCE INTO THE EASTERN TWO THIRDS OF THE CONUS. A NARROW HIGH
AMPLITUDE RIDGE HAS DEVELOPED OVER THE WESTERN THIRD OF THE US AND
CANADA. NORTHEAST MONTANA STANDS BETWEEN THESE TWO FEATURES UNDER
NORTHERN TO NORTHWESTERN FLOW ALOFT. FARTHER WEST ANOTHER MORE
NARROW TROUGH EXTENDS FROM OFF THE COASTS OF BRITISH COLUMBIA TO
SOUTHERN CALIFORNIA.

TONIGHT... DRY NORTHERN FLOW ALOFT AND SURFACE HIGH PRESSURE ACROSS
THE REGION WILL ACT TO KEEP NORTHEASTERN MONTANA DRY AND CLEAR.

FRIDAY THROUGH FRIDAY NIGHT... WITH ATMOSPHERE SLOWLY MODIFYING
WARMER AT THE SURFACE AND COOLER MID LEVEL AIR ENTER IN THE REGION
FROM THE SOUTHEAST SOME INSTABILITY IS EXPECTED TO DEVELOPED
FRIDAY AFTERNOON. AREAS OF OROGRAPHIC LIFT SUCH AS THE CENTRAL
MONTANA MOUNTAINS ARE WHERE THIS INSTABILITY SHOULD INITIALIZE.
SOME SPILL OVER INT THE AFTERNOON AND EVENINGS HOURS IS POSSIBLE
FOR PETROLEUM... PHILLIPS... AND WESTERN GARFIELD COUNTY.

STRONG SURFACE WINDS WILL ALSO ALLOW FOR A LAKE WIND ADVISORY TO
BE IN AFFECT DURING THE AFTERNOON HOURS.

SATURDAY... A CHANCE FOR MOUNTAIN INSTABILITY STILL EXISTS BUT
LESSENS. FOCUS SHIFTS TO THE SOUTHEASTERN CWA WITH A COLD AIR
POCKET DEVELOPING OVER THE DAKOTAS AND EASTERN MT. THIS WILL
ALLOW A LIFT ZONE TO FORM AND SHOWERS TO SPILL INTO THE YELLOWSTONE
VALLEY THAT AFTERNOON AND EVENING. GAH


.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
12Z MODELS REMAINED INCONSISTENT WITH PRECIP PLACEMENT LATER THIS
WEEKEND. THIS TIME THE GFS DRAGGED PRECIP INTO THE CWA FROM THE
SOUTHEAST AND WAS SLOWER TO PUSH IT OUT OF HERE EARLY NEXT WEEK.
MAINLY TRIMMED POPS AS THE PRECIP AREA HAS TRENDED EAST A BIT.
INSTABILITY WITH THE NEIGHBORING UPPER LOW WILL LEAD TO SLIGHT
CHANCE OF SHOWERS. TFJ


PREVIOUS DISCUSSION...
SATURDAY NIGHT AND SUNDAY FEATURES A BROAD UPPER TROUGH OVER THE
WEST AND AN UPPER RIDGE TO EAST OF NORTHEAST MONTANA. THE TROUGH
WILL LIFT NORTH INTO MONTANA AND NORTH DAKOTA BY MONDAY. THEN...THE
FLOW PATTERN ALOFT OVER MONTANA WILL BE WEAK...VARIABLE AND UN-
FOCUSED MONDAY AND TUESDAY. THE SOUTHEAST HALF OF THE FORECAST
AREA HAS A BETTER CHANCE OF SEEING SHOWERS MAYBE THUNDERSTORMS AT
TIMES BETWEEN SATURDAY NIGHT AND MONDAY WHERE THE DEEPER MOISTURE
IS EXPECTED.

MODEL DIFFERENCES SHOW UP TUESDAY AND BEYOND AS GFS HAS A NW FLOW
ALOFT WITH A BACK DOOR COLD FRONT ON WEDNESDAY. ECMWF HAS AN UPPER
TROUGH OVER THE PACIFIC NW ON TUESDAY THAT EVENTUALLY MOVES EAST
ACROSS MONTANA WEDNESDAY AND THURSDAY. WILL MAINTAIN A
CHANCE/SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR NOW.
FORRESTER


&&

.AVIATION...
VFR.

MAINLY CLEAR SKIES TONIGHT AND FRIDAY. SOUTHEAST WINDS AROUND 10
KTS EXCEPT LIGHT AT KSDY. SOUTHEAST WINDS WILL BE STRONGER FRIDAY.
TFJ


&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM 11 AM TO 8 PM MDT FRIDAY FOR FORT PECK
LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN
VALLEY...GARFIELD...MCCONE...PETROLEUM.


&&

$$

WEATHER.GOV/GLASGOW






000
FXUS65 KGGW 212037
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
237 PM MDT THU MAY 21 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SATURDAY...

SYNOPTIC SET UP... A CLOSED LOW SETS OVER THE QUEBEC/ONTARIO
BORDER WITH A LARGE TROUGH SURROUNDING IT AND EXTENDING ITS
INFLUENCE INTO THE EASTERN TWO THIRDS OF THE CONUS. A NARROW HIGH
AMPLITUDE RIDGE HAS DEVELOPED OVER THE WESTERN THIRD OF THE US AND
CANADA. NORTHEAST MONTANA STANDS BETWEEN THESE TWO FEATURES UNDER
NORTHERN TO NORTHWESTERN FLOW ALOFT. FARTHER WEST ANOTHER MORE
NARROW TROUGH EXTENDS FROM OFF THE COASTS OF BRITISH COLUMBIA TO
SOUTHERN CALIFORNIA.

TONIGHT... DRY NORTHERN FLOW ALOFT AND SURFACE HIGH PRESSURE ACROSS
THE REGION WILL ACT TO KEEP NORTHEASTERN MONTANA DRY AND CLEAR.

FRIDAY THROUGH FRIDAY NIGHT... WITH ATMOSPHERE SLOWLY MODIFYING
WARMER AT THE SURFACE AND COOLER MID LEVEL AIR ENTER IN THE REGION
FROM THE SOUTHEAST SOME INSTABILITY IS EXPECTED TO DEVELOPED
FRIDAY AFTERNOON. AREAS OF OROGRAPHIC LIFT SUCH AS THE CENTRAL
MONTANA MOUNTAINS ARE WHERE THIS INSTABILITY SHOULD INITIALIZE.
SOME SPILL OVER INT THE AFTERNOON AND EVENINGS HOURS IS POSSIBLE
FOR PETROLEUM... PHILLIPS... AND WESTERN GARFIELD COUNTY.

STRONG SURFACE WINDS WILL ALSO ALLOW FOR A LAKE WIND ADVISORY TO
BE IN AFFECT DURING THE AFTERNOON HOURS.

SATURDAY... A CHANCE FOR MOUNTAIN INSTABILITY STILL EXISTS BUT
LESSENS. FOCUS SHIFTS TO THE SOUTHEASTERN CWA WITH A COLD AIR
POCKET DEVELOPING OVER THE DAKOTAS AND EASTERN MT. THIS WILL
ALLOW A LIFT ZONE TO FORM AND SHOWERS TO SPILL INTO THE YELLOWSTONE
VALLEY THAT AFTERNOON AND EVENING. GAH


.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
12Z MODELS REMAINED INCONSISTENT WITH PRECIP PLACEMENT LATER THIS
WEEKEND. THIS TIME THE GFS DRAGGED PRECIP INTO THE CWA FROM THE
SOUTHEAST AND WAS SLOWER TO PUSH IT OUT OF HERE EARLY NEXT WEEK.
MAINLY TRIMMED POPS AS THE PRECIP AREA HAS TRENDED EAST A BIT.
INSTABILITY WITH THE NEIGHBORING UPPER LOW WILL LEAD TO SLIGHT
CHANCE OF SHOWERS. TFJ


PREVIOUS DISCUSSION...
SATURDAY NIGHT AND SUNDAY FEATURES A BROAD UPPER TROUGH OVER THE
WEST AND AN UPPER RIDGE TO EAST OF NORTHEAST MONTANA. THE TROUGH
WILL LIFT NORTH INTO MONTANA AND NORTH DAKOTA BY MONDAY. THEN...THE
FLOW PATTERN ALOFT OVER MONTANA WILL BE WEAK...VARIABLE AND UN-
FOCUSED MONDAY AND TUESDAY. THE SOUTHEAST HALF OF THE FORECAST
AREA HAS A BETTER CHANCE OF SEEING SHOWERS MAYBE THUNDERSTORMS AT
TIMES BETWEEN SATURDAY NIGHT AND MONDAY WHERE THE DEEPER MOISTURE
IS EXPECTED.

MODEL DIFFERENCES SHOW UP TUESDAY AND BEYOND AS GFS HAS A NW FLOW
ALOFT WITH A BACK DOOR COLD FRONT ON WEDNESDAY. ECMWF HAS AN UPPER
TROUGH OVER THE PACIFIC NW ON TUESDAY THAT EVENTUALLY MOVES EAST
ACROSS MONTANA WEDNESDAY AND THURSDAY. WILL MAINTAIN A
CHANCE/SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR NOW.
FORRESTER


&&

.AVIATION...
VFR.

MAINLY CLEAR SKIES TONIGHT AND FRIDAY. SOUTHEAST WINDS AROUND 10
KTS EXCEPT LIGHT AT KSDY. SOUTHEAST WINDS WILL BE STRONGER FRIDAY.
TFJ


&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM 11 AM TO 8 PM MDT FRIDAY FOR FORT PECK
LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN
VALLEY...GARFIELD...MCCONE...PETROLEUM.


&&

$$

WEATHER.GOV/GLASGOW






000
FXUS65 KGGW 212037
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
237 PM MDT THU MAY 21 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SATURDAY...

SYNOPTIC SET UP... A CLOSED LOW SETS OVER THE QUEBEC/ONTARIO
BORDER WITH A LARGE TROUGH SURROUNDING IT AND EXTENDING ITS
INFLUENCE INTO THE EASTERN TWO THIRDS OF THE CONUS. A NARROW HIGH
AMPLITUDE RIDGE HAS DEVELOPED OVER THE WESTERN THIRD OF THE US AND
CANADA. NORTHEAST MONTANA STANDS BETWEEN THESE TWO FEATURES UNDER
NORTHERN TO NORTHWESTERN FLOW ALOFT. FARTHER WEST ANOTHER MORE
NARROW TROUGH EXTENDS FROM OFF THE COASTS OF BRITISH COLUMBIA TO
SOUTHERN CALIFORNIA.

TONIGHT... DRY NORTHERN FLOW ALOFT AND SURFACE HIGH PRESSURE ACROSS
THE REGION WILL ACT TO KEEP NORTHEASTERN MONTANA DRY AND CLEAR.

FRIDAY THROUGH FRIDAY NIGHT... WITH ATMOSPHERE SLOWLY MODIFYING
WARMER AT THE SURFACE AND COOLER MID LEVEL AIR ENTER IN THE REGION
FROM THE SOUTHEAST SOME INSTABILITY IS EXPECTED TO DEVELOPED
FRIDAY AFTERNOON. AREAS OF OROGRAPHIC LIFT SUCH AS THE CENTRAL
MONTANA MOUNTAINS ARE WHERE THIS INSTABILITY SHOULD INITIALIZE.
SOME SPILL OVER INT THE AFTERNOON AND EVENINGS HOURS IS POSSIBLE
FOR PETROLEUM... PHILLIPS... AND WESTERN GARFIELD COUNTY.

STRONG SURFACE WINDS WILL ALSO ALLOW FOR A LAKE WIND ADVISORY TO
BE IN AFFECT DURING THE AFTERNOON HOURS.

SATURDAY... A CHANCE FOR MOUNTAIN INSTABILITY STILL EXISTS BUT
LESSENS. FOCUS SHIFTS TO THE SOUTHEASTERN CWA WITH A COLD AIR
POCKET DEVELOPING OVER THE DAKOTAS AND EASTERN MT. THIS WILL
ALLOW A LIFT ZONE TO FORM AND SHOWERS TO SPILL INTO THE YELLOWSTONE
VALLEY THAT AFTERNOON AND EVENING. GAH


.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
12Z MODELS REMAINED INCONSISTENT WITH PRECIP PLACEMENT LATER THIS
WEEKEND. THIS TIME THE GFS DRAGGED PRECIP INTO THE CWA FROM THE
SOUTHEAST AND WAS SLOWER TO PUSH IT OUT OF HERE EARLY NEXT WEEK.
MAINLY TRIMMED POPS AS THE PRECIP AREA HAS TRENDED EAST A BIT.
INSTABILITY WITH THE NEIGHBORING UPPER LOW WILL LEAD TO SLIGHT
CHANCE OF SHOWERS. TFJ


PREVIOUS DISCUSSION...
SATURDAY NIGHT AND SUNDAY FEATURES A BROAD UPPER TROUGH OVER THE
WEST AND AN UPPER RIDGE TO EAST OF NORTHEAST MONTANA. THE TROUGH
WILL LIFT NORTH INTO MONTANA AND NORTH DAKOTA BY MONDAY. THEN...THE
FLOW PATTERN ALOFT OVER MONTANA WILL BE WEAK...VARIABLE AND UN-
FOCUSED MONDAY AND TUESDAY. THE SOUTHEAST HALF OF THE FORECAST
AREA HAS A BETTER CHANCE OF SEEING SHOWERS MAYBE THUNDERSTORMS AT
TIMES BETWEEN SATURDAY NIGHT AND MONDAY WHERE THE DEEPER MOISTURE
IS EXPECTED.

MODEL DIFFERENCES SHOW UP TUESDAY AND BEYOND AS GFS HAS A NW FLOW
ALOFT WITH A BACK DOOR COLD FRONT ON WEDNESDAY. ECMWF HAS AN UPPER
TROUGH OVER THE PACIFIC NW ON TUESDAY THAT EVENTUALLY MOVES EAST
ACROSS MONTANA WEDNESDAY AND THURSDAY. WILL MAINTAIN A
CHANCE/SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR NOW.
FORRESTER


&&

.AVIATION...
VFR.

MAINLY CLEAR SKIES TONIGHT AND FRIDAY. SOUTHEAST WINDS AROUND 10
KTS EXCEPT LIGHT AT KSDY. SOUTHEAST WINDS WILL BE STRONGER FRIDAY.
TFJ


&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM 11 AM TO 8 PM MDT FRIDAY FOR FORT PECK
LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN
VALLEY...GARFIELD...MCCONE...PETROLEUM.


&&

$$

WEATHER.GOV/GLASGOW






000
FXUS65 KGGW 212037
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
237 PM MDT THU MAY 21 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SATURDAY...

SYNOPTIC SET UP... A CLOSED LOW SETS OVER THE QUEBEC/ONTARIO
BORDER WITH A LARGE TROUGH SURROUNDING IT AND EXTENDING ITS
INFLUENCE INTO THE EASTERN TWO THIRDS OF THE CONUS. A NARROW HIGH
AMPLITUDE RIDGE HAS DEVELOPED OVER THE WESTERN THIRD OF THE US AND
CANADA. NORTHEAST MONTANA STANDS BETWEEN THESE TWO FEATURES UNDER
NORTHERN TO NORTHWESTERN FLOW ALOFT. FARTHER WEST ANOTHER MORE
NARROW TROUGH EXTENDS FROM OFF THE COASTS OF BRITISH COLUMBIA TO
SOUTHERN CALIFORNIA.

TONIGHT... DRY NORTHERN FLOW ALOFT AND SURFACE HIGH PRESSURE ACROSS
THE REGION WILL ACT TO KEEP NORTHEASTERN MONTANA DRY AND CLEAR.

FRIDAY THROUGH FRIDAY NIGHT... WITH ATMOSPHERE SLOWLY MODIFYING
WARMER AT THE SURFACE AND COOLER MID LEVEL AIR ENTER IN THE REGION
FROM THE SOUTHEAST SOME INSTABILITY IS EXPECTED TO DEVELOPED
FRIDAY AFTERNOON. AREAS OF OROGRAPHIC LIFT SUCH AS THE CENTRAL
MONTANA MOUNTAINS ARE WHERE THIS INSTABILITY SHOULD INITIALIZE.
SOME SPILL OVER INT THE AFTERNOON AND EVENINGS HOURS IS POSSIBLE
FOR PETROLEUM... PHILLIPS... AND WESTERN GARFIELD COUNTY.

STRONG SURFACE WINDS WILL ALSO ALLOW FOR A LAKE WIND ADVISORY TO
BE IN AFFECT DURING THE AFTERNOON HOURS.

SATURDAY... A CHANCE FOR MOUNTAIN INSTABILITY STILL EXISTS BUT
LESSENS. FOCUS SHIFTS TO THE SOUTHEASTERN CWA WITH A COLD AIR
POCKET DEVELOPING OVER THE DAKOTAS AND EASTERN MT. THIS WILL
ALLOW A LIFT ZONE TO FORM AND SHOWERS TO SPILL INTO THE YELLOWSTONE
VALLEY THAT AFTERNOON AND EVENING. GAH


.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
12Z MODELS REMAINED INCONSISTENT WITH PRECIP PLACEMENT LATER THIS
WEEKEND. THIS TIME THE GFS DRAGGED PRECIP INTO THE CWA FROM THE
SOUTHEAST AND WAS SLOWER TO PUSH IT OUT OF HERE EARLY NEXT WEEK.
MAINLY TRIMMED POPS AS THE PRECIP AREA HAS TRENDED EAST A BIT.
INSTABILITY WITH THE NEIGHBORING UPPER LOW WILL LEAD TO SLIGHT
CHANCE OF SHOWERS. TFJ


PREVIOUS DISCUSSION...
SATURDAY NIGHT AND SUNDAY FEATURES A BROAD UPPER TROUGH OVER THE
WEST AND AN UPPER RIDGE TO EAST OF NORTHEAST MONTANA. THE TROUGH
WILL LIFT NORTH INTO MONTANA AND NORTH DAKOTA BY MONDAY. THEN...THE
FLOW PATTERN ALOFT OVER MONTANA WILL BE WEAK...VARIABLE AND UN-
FOCUSED MONDAY AND TUESDAY. THE SOUTHEAST HALF OF THE FORECAST
AREA HAS A BETTER CHANCE OF SEEING SHOWERS MAYBE THUNDERSTORMS AT
TIMES BETWEEN SATURDAY NIGHT AND MONDAY WHERE THE DEEPER MOISTURE
IS EXPECTED.

MODEL DIFFERENCES SHOW UP TUESDAY AND BEYOND AS GFS HAS A NW FLOW
ALOFT WITH A BACK DOOR COLD FRONT ON WEDNESDAY. ECMWF HAS AN UPPER
TROUGH OVER THE PACIFIC NW ON TUESDAY THAT EVENTUALLY MOVES EAST
ACROSS MONTANA WEDNESDAY AND THURSDAY. WILL MAINTAIN A
CHANCE/SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR NOW.
FORRESTER


&&

.AVIATION...
VFR.

MAINLY CLEAR SKIES TONIGHT AND FRIDAY. SOUTHEAST WINDS AROUND 10
KTS EXCEPT LIGHT AT KSDY. SOUTHEAST WINDS WILL BE STRONGER FRIDAY.
TFJ


&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM 11 AM TO 8 PM MDT FRIDAY FOR FORT PECK
LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN
VALLEY...GARFIELD...MCCONE...PETROLEUM.


&&

$$

WEATHER.GOV/GLASGOW






000
FXUS65 KTFX 211806
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1210 PM MDT THU MAY 21 2015

AVIATION SECTION UPDATED

.DISCUSSION...HAVE OPTED TO NOT MAKE ANY UPDATES THIS MORNING AS
THE GOING FORECAST APPEARS TO BE IN EXCELLENT SHAPE. SCATTERED
SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER SOUTHWEST AND SOUTH
CENTRAL MONTANA THIS AFTERNOON AND MOVE INTO SOUTHERN PORTIONS OF
CENTRAL MONTANA BY EVENING. CONVECTION WILL BE DRIVEN BY DIURNAL
INSTABILITY SO EXPECT THAT PRECIPITATION WILL TAPER OFF RAPIDLY
AFTER SUNSET. ALSO DO NOT EXPECT THAT ANY STORMS WILL BECOME
STRONG TO SEVERE AS INSTABILITY AND SHEAR ARE WEAK. HOWEVER, ANY
STORMS THAT DO FORM COULD PRODUCE SOME LOCALLY HEAVY RAIN. MPJ

&&

.AVIATION...
UPDATED 1050Z.
VFR CONDITIONS WILL CONTINUE OVER NORTH CENTRAL MT THROUGH THE
PERIOD. OVER SOUTHWEST MT...EXPECT SCATTERED THUNDERSTORMS THIS
AFTERNOON AND INTO THE EVENING HOURS...MAINLY BEFORE 03Z FRIDAY.
GUSTY WINDS TO NEAR 30 KTS ARE POSSIBLE WITH A FEW OF THE STRONGER
THUNDERSTORMS. BRUSDA

&&

.PREV DISCUSSION...
/ISSUED 450 AM MDT THU MAY 21 2015/
THURSDAY THROUGH SATURDAY...
SHOWERS AND THUNDERSTORMS WILL BECOME MORE PREVALENT OVER THE NEXT
FEW DAYS AS MOISTURE FROM A LOW PRESSURE SYSTEM MOVING ACROSS THE
SOUTHERN US IS EJECTED UP INTO FROM THE SOUTH. THE SYSTEM LOOKS TO
STAY FAR ENOUGH TO THE SOUTH TO ELIMINATE THE CHANCE OF A
WIDESPREAD WETTING RAIN...INSTEAD AFTERNOON SHOWERS AND
THUNDERSTORMS LOOK TO DEVELOP EACH AFTERNOON AND SHOULD INCREASE
IN COVERAGE OF THE AREA THROUGH THE FIRST HALF OF THE WEEKEND.
RELATIVELY WEAK SHEAR WILL LIMIT THE CHANCES FOR ANY OF THE
SHOWERS OR THUNDERSTORMS TO DEVELOP INTO SEVERE STORMS...BUT
STRONG STORMS ARE POSSIBLE AND COULD PRODUCE SMALL HAIL AND GUSTY
WINDS ALONG WITH BRIEF HEAVY RAINFALL. MODELS SUGGEST THAT THERE
IS ENOUGH WIND ALOFT TO ALLOW FOR STORMS TO MOVE OFF OF ANY
INITIATION POINT AND THIS SHOULD LIMIT THE POTENTIAL FOR LONG
DURATION HEAVY RAINS FROM NEARLY STATIONARY STORMS. TEMPERATURES
ARE EXPECTED TO BE NEAR OR SLIGHTLY ABOVE SEASONAL AVERAGES
THROUGH FRIDAY WITH ONLY A SLIGHT COOLDOWN TO SEASONAL AVERAGES ON
SATURDAY. WINDS SHOULD BE LIGHT AND EASTERLY AGAIN TODAY...WITH
SOME LOCATIONS BECOMING GUSTY IN THE AFTERNOON...ESPECIALLY NEAR
ANY SHOWER OR THUNDERSTORM. SUK

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  42  70  47 /  20  10  20  30
CTB  68  38  69  41 /   0   0  10  10
HLN  70  45  71  49 /  40  30  30  30
BZN  66  40  69  43 /  50  20  40  30
WEY  59  32  62  35 /  60  40  60  40
DLN  64  41  67  44 /  70  50  40  40
HVR  71  38  74  43 /   0   0  10  30
LWT  66  42  68  45 /   0  10  40  50

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

WEATHER.GOV/GREATFALLS




000
FXUS65 KTFX 211806
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1210 PM MDT THU MAY 21 2015

AVIATION SECTION UPDATED

.DISCUSSION...HAVE OPTED TO NOT MAKE ANY UPDATES THIS MORNING AS
THE GOING FORECAST APPEARS TO BE IN EXCELLENT SHAPE. SCATTERED
SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER SOUTHWEST AND SOUTH
CENTRAL MONTANA THIS AFTERNOON AND MOVE INTO SOUTHERN PORTIONS OF
CENTRAL MONTANA BY EVENING. CONVECTION WILL BE DRIVEN BY DIURNAL
INSTABILITY SO EXPECT THAT PRECIPITATION WILL TAPER OFF RAPIDLY
AFTER SUNSET. ALSO DO NOT EXPECT THAT ANY STORMS WILL BECOME
STRONG TO SEVERE AS INSTABILITY AND SHEAR ARE WEAK. HOWEVER, ANY
STORMS THAT DO FORM COULD PRODUCE SOME LOCALLY HEAVY RAIN. MPJ

&&

.AVIATION...
UPDATED 1050Z.
VFR CONDITIONS WILL CONTINUE OVER NORTH CENTRAL MT THROUGH THE
PERIOD. OVER SOUTHWEST MT...EXPECT SCATTERED THUNDERSTORMS THIS
AFTERNOON AND INTO THE EVENING HOURS...MAINLY BEFORE 03Z FRIDAY.
GUSTY WINDS TO NEAR 30 KTS ARE POSSIBLE WITH A FEW OF THE STRONGER
THUNDERSTORMS. BRUSDA

&&

.PREV DISCUSSION...
/ISSUED 450 AM MDT THU MAY 21 2015/
THURSDAY THROUGH SATURDAY...
SHOWERS AND THUNDERSTORMS WILL BECOME MORE PREVALENT OVER THE NEXT
FEW DAYS AS MOISTURE FROM A LOW PRESSURE SYSTEM MOVING ACROSS THE
SOUTHERN US IS EJECTED UP INTO FROM THE SOUTH. THE SYSTEM LOOKS TO
STAY FAR ENOUGH TO THE SOUTH TO ELIMINATE THE CHANCE OF A
WIDESPREAD WETTING RAIN...INSTEAD AFTERNOON SHOWERS AND
THUNDERSTORMS LOOK TO DEVELOP EACH AFTERNOON AND SHOULD INCREASE
IN COVERAGE OF THE AREA THROUGH THE FIRST HALF OF THE WEEKEND.
RELATIVELY WEAK SHEAR WILL LIMIT THE CHANCES FOR ANY OF THE
SHOWERS OR THUNDERSTORMS TO DEVELOP INTO SEVERE STORMS...BUT
STRONG STORMS ARE POSSIBLE AND COULD PRODUCE SMALL HAIL AND GUSTY
WINDS ALONG WITH BRIEF HEAVY RAINFALL. MODELS SUGGEST THAT THERE
IS ENOUGH WIND ALOFT TO ALLOW FOR STORMS TO MOVE OFF OF ANY
INITIATION POINT AND THIS SHOULD LIMIT THE POTENTIAL FOR LONG
DURATION HEAVY RAINS FROM NEARLY STATIONARY STORMS. TEMPERATURES
ARE EXPECTED TO BE NEAR OR SLIGHTLY ABOVE SEASONAL AVERAGES
THROUGH FRIDAY WITH ONLY A SLIGHT COOLDOWN TO SEASONAL AVERAGES ON
SATURDAY. WINDS SHOULD BE LIGHT AND EASTERLY AGAIN TODAY...WITH
SOME LOCATIONS BECOMING GUSTY IN THE AFTERNOON...ESPECIALLY NEAR
ANY SHOWER OR THUNDERSTORM. SUK

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  42  70  47 /  20  10  20  30
CTB  68  38  69  41 /   0   0  10  10
HLN  70  45  71  49 /  40  30  30  30
BZN  66  40  69  43 /  50  20  40  30
WEY  59  32  62  35 /  60  40  60  40
DLN  64  41  67  44 /  70  50  40  40
HVR  71  38  74  43 /   0   0  10  30
LWT  66  42  68  45 /   0  10  40  50

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

WEATHER.GOV/GREATFALLS




000
FXUS65 KTFX 211806
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1210 PM MDT THU MAY 21 2015

AVIATION SECTION UPDATED

.DISCUSSION...HAVE OPTED TO NOT MAKE ANY UPDATES THIS MORNING AS
THE GOING FORECAST APPEARS TO BE IN EXCELLENT SHAPE. SCATTERED
SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER SOUTHWEST AND SOUTH
CENTRAL MONTANA THIS AFTERNOON AND MOVE INTO SOUTHERN PORTIONS OF
CENTRAL MONTANA BY EVENING. CONVECTION WILL BE DRIVEN BY DIURNAL
INSTABILITY SO EXPECT THAT PRECIPITATION WILL TAPER OFF RAPIDLY
AFTER SUNSET. ALSO DO NOT EXPECT THAT ANY STORMS WILL BECOME
STRONG TO SEVERE AS INSTABILITY AND SHEAR ARE WEAK. HOWEVER, ANY
STORMS THAT DO FORM COULD PRODUCE SOME LOCALLY HEAVY RAIN. MPJ

&&

.AVIATION...
UPDATED 1050Z.
VFR CONDITIONS WILL CONTINUE OVER NORTH CENTRAL MT THROUGH THE
PERIOD. OVER SOUTHWEST MT...EXPECT SCATTERED THUNDERSTORMS THIS
AFTERNOON AND INTO THE EVENING HOURS...MAINLY BEFORE 03Z FRIDAY.
GUSTY WINDS TO NEAR 30 KTS ARE POSSIBLE WITH A FEW OF THE STRONGER
THUNDERSTORMS. BRUSDA

&&

.PREV DISCUSSION...
/ISSUED 450 AM MDT THU MAY 21 2015/
THURSDAY THROUGH SATURDAY...
SHOWERS AND THUNDERSTORMS WILL BECOME MORE PREVALENT OVER THE NEXT
FEW DAYS AS MOISTURE FROM A LOW PRESSURE SYSTEM MOVING ACROSS THE
SOUTHERN US IS EJECTED UP INTO FROM THE SOUTH. THE SYSTEM LOOKS TO
STAY FAR ENOUGH TO THE SOUTH TO ELIMINATE THE CHANCE OF A
WIDESPREAD WETTING RAIN...INSTEAD AFTERNOON SHOWERS AND
THUNDERSTORMS LOOK TO DEVELOP EACH AFTERNOON AND SHOULD INCREASE
IN COVERAGE OF THE AREA THROUGH THE FIRST HALF OF THE WEEKEND.
RELATIVELY WEAK SHEAR WILL LIMIT THE CHANCES FOR ANY OF THE
SHOWERS OR THUNDERSTORMS TO DEVELOP INTO SEVERE STORMS...BUT
STRONG STORMS ARE POSSIBLE AND COULD PRODUCE SMALL HAIL AND GUSTY
WINDS ALONG WITH BRIEF HEAVY RAINFALL. MODELS SUGGEST THAT THERE
IS ENOUGH WIND ALOFT TO ALLOW FOR STORMS TO MOVE OFF OF ANY
INITIATION POINT AND THIS SHOULD LIMIT THE POTENTIAL FOR LONG
DURATION HEAVY RAINS FROM NEARLY STATIONARY STORMS. TEMPERATURES
ARE EXPECTED TO BE NEAR OR SLIGHTLY ABOVE SEASONAL AVERAGES
THROUGH FRIDAY WITH ONLY A SLIGHT COOLDOWN TO SEASONAL AVERAGES ON
SATURDAY. WINDS SHOULD BE LIGHT AND EASTERLY AGAIN TODAY...WITH
SOME LOCATIONS BECOMING GUSTY IN THE AFTERNOON...ESPECIALLY NEAR
ANY SHOWER OR THUNDERSTORM. SUK

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  42  70  47 /  20  10  20  30
CTB  68  38  69  41 /   0   0  10  10
HLN  70  45  71  49 /  40  30  30  30
BZN  66  40  69  43 /  50  20  40  30
WEY  59  32  62  35 /  60  40  60  40
DLN  64  41  67  44 /  70  50  40  40
HVR  71  38  74  43 /   0   0  10  30
LWT  66  42  68  45 /   0  10  40  50

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 211611
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1011 AM MDT THU MAY 21 2015

.DISCUSSION...HAVE OPTED TO NOT MAKE ANY UPDATES THIS MORNING AS
THE GOING FORECAST APPEARS TO BE IN EXCELLENT SHAPE. SCATTERED
SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER SOUTHWEST AND SOUTH
CENTRAL MONTANA THIS AFTERNOON AND MOVE INTO SOUTHERN PORTIONS OF
CENTRAL MONTANA BY EVENING. CONVECTION WILL BE DRIVEN BY DIURNAL
INSTABILITY SO EXPECT THAT PRECIPITATION WILL TAPER OFF RAPIDLY
AFTER SUNSET. ALSO DO NOT EXPECT THAT ANY STORMS WILL BECOME
STRONG TO SEVERE AS INSTABILITY AND SHEAR ARE WEAK. HOWEVER, ANY
STORMS THAT DO FORM COULD PRODUCE SOME LOCALLY HEAVY RAIN. MPJ

&&

.AVIATION... UPDATED 1050Z. VFR CONDITIONS ARE ONCE AGAIN EXPECTED.
CLEAR SKIES TO A FEW CLOUDS AROUND 12000 FT CAN BE EXPECTED NEAR AND
NORTH OF A LINE FROM KLWT THROUGH KGTF. SOUTH OF THAT LINE EXPECT
ISOLATED SHOWERS THIS MORNING WITH SCATTERED SHOWERS BUT NUMEROUS
SHOWERS OVER THE MOUNTAINS THIS AFTERNOON. ALSO EXPECT SCATTERED
THUNDERSTORMS THIS AFTERNOON. GUSTY WINDS TO NEAR 40 KTS CAN BE
EXPECTED WITH A FEW OF THE THUNDERSTORMS. SHOWERS AND THUNDERSTORMS
WILL MOSTLY DISSIPATE NEAR AND AFTER MIDNIGHT. CONFIDENCE IN
FORECAST WINDS IS ABOVE AVERAGE. BLANK

&&

.PREV DISCUSSION...
/ISSUED 450 AM MDT THU MAY 21 2015/
THURSDAY THROUGH SATURDAY...
SHOWERS AND THUNDERSTORMS WILL BECOME MORE PREVALENT OVER THE NEXT
FEW DAYS AS MOISTURE FROM A LOW PRESSURE SYSTEM MOVING ACROSS THE
SOUTHERN US IS EJECTED UP INTO FROM THE SOUTH. THE SYSTEM LOOKS TO
STAY FAR ENOUGH TO THE SOUTH TO ELIMINATE THE CHANCE OF A
WIDESPREAD WETTING RAIN...INSTEAD AFTERNOON SHOWERS AND
THUNDERSTORMS LOOK TO DEVELOP EACH AFTERNOON AND SHOULD INCREASE
IN COVERAGE OF THE AREA THROUGH THE FIRST HALF OF THE WEEKEND.
RELATIVELY WEAK SHEAR WILL LIMIT THE CHANCES FOR ANY OF THE
SHOWERS OR THUNDERSTORMS TO DEVELOP INTO SEVERE STORMS...BUT
STRONG STORMS ARE POSSIBLE AND COULD PRODUCE SMALL HAIL AND GUSTY
WINDS ALONG WITH BRIEF HEAVY RAINFALL. MODELS SUGGEST THAT THERE
IS ENOUGH WIND ALOFT TO ALLOW FOR STORMS TO MOVE OFF OF ANY
INITIATION POINT AND THIS SHOULD LIMIT THE POTENTIAL FOR LONG
DURATION HEAVY RAINS FROM NEARLY STATIONARY STORMS. TEMPERATURES
ARE EXPECTED TO BE NEAR OR SLIGHTLY ABOVE SEASONAL AVERAGES
THROUGH FRIDAY WITH ONLY A SLIGHT COOLDOWN TO SEASONAL AVERAGES ON
SATURDAY. WINDS SHOULD BE LIGHT AND EASTERLY AGAIN TODAY...WITH
SOME LOCATIONS BECOMING GUSTY IN THE AFTERNOON...ESPECIALLY NEAR
ANY SHOWER OR THUNDERSTORM. SUK

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  42  70  47 /  20  10  20  30
CTB  68  38  69  41 /   0   0  10  10
HLN  70  45  71  49 /  40  30  30  30
BZN  66  40  69  43 /  50  20  40  30
WEY  59  32  62  35 /  60  40  60  40
DLN  64  41  67  44 /  70  50  40  40
HVR  71  38  74  43 /   0   0  10  30
LWT  66  42  68  45 /   0  10  40  50

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 211611
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1011 AM MDT THU MAY 21 2015

.DISCUSSION...HAVE OPTED TO NOT MAKE ANY UPDATES THIS MORNING AS
THE GOING FORECAST APPEARS TO BE IN EXCELLENT SHAPE. SCATTERED
SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER SOUTHWEST AND SOUTH
CENTRAL MONTANA THIS AFTERNOON AND MOVE INTO SOUTHERN PORTIONS OF
CENTRAL MONTANA BY EVENING. CONVECTION WILL BE DRIVEN BY DIURNAL
INSTABILITY SO EXPECT THAT PRECIPITATION WILL TAPER OFF RAPIDLY
AFTER SUNSET. ALSO DO NOT EXPECT THAT ANY STORMS WILL BECOME
STRONG TO SEVERE AS INSTABILITY AND SHEAR ARE WEAK. HOWEVER, ANY
STORMS THAT DO FORM COULD PRODUCE SOME LOCALLY HEAVY RAIN. MPJ

&&

.AVIATION... UPDATED 1050Z. VFR CONDITIONS ARE ONCE AGAIN EXPECTED.
CLEAR SKIES TO A FEW CLOUDS AROUND 12000 FT CAN BE EXPECTED NEAR AND
NORTH OF A LINE FROM KLWT THROUGH KGTF. SOUTH OF THAT LINE EXPECT
ISOLATED SHOWERS THIS MORNING WITH SCATTERED SHOWERS BUT NUMEROUS
SHOWERS OVER THE MOUNTAINS THIS AFTERNOON. ALSO EXPECT SCATTERED
THUNDERSTORMS THIS AFTERNOON. GUSTY WINDS TO NEAR 40 KTS CAN BE
EXPECTED WITH A FEW OF THE THUNDERSTORMS. SHOWERS AND THUNDERSTORMS
WILL MOSTLY DISSIPATE NEAR AND AFTER MIDNIGHT. CONFIDENCE IN
FORECAST WINDS IS ABOVE AVERAGE. BLANK

&&

.PREV DISCUSSION...
/ISSUED 450 AM MDT THU MAY 21 2015/
THURSDAY THROUGH SATURDAY...
SHOWERS AND THUNDERSTORMS WILL BECOME MORE PREVALENT OVER THE NEXT
FEW DAYS AS MOISTURE FROM A LOW PRESSURE SYSTEM MOVING ACROSS THE
SOUTHERN US IS EJECTED UP INTO FROM THE SOUTH. THE SYSTEM LOOKS TO
STAY FAR ENOUGH TO THE SOUTH TO ELIMINATE THE CHANCE OF A
WIDESPREAD WETTING RAIN...INSTEAD AFTERNOON SHOWERS AND
THUNDERSTORMS LOOK TO DEVELOP EACH AFTERNOON AND SHOULD INCREASE
IN COVERAGE OF THE AREA THROUGH THE FIRST HALF OF THE WEEKEND.
RELATIVELY WEAK SHEAR WILL LIMIT THE CHANCES FOR ANY OF THE
SHOWERS OR THUNDERSTORMS TO DEVELOP INTO SEVERE STORMS...BUT
STRONG STORMS ARE POSSIBLE AND COULD PRODUCE SMALL HAIL AND GUSTY
WINDS ALONG WITH BRIEF HEAVY RAINFALL. MODELS SUGGEST THAT THERE
IS ENOUGH WIND ALOFT TO ALLOW FOR STORMS TO MOVE OFF OF ANY
INITIATION POINT AND THIS SHOULD LIMIT THE POTENTIAL FOR LONG
DURATION HEAVY RAINS FROM NEARLY STATIONARY STORMS. TEMPERATURES
ARE EXPECTED TO BE NEAR OR SLIGHTLY ABOVE SEASONAL AVERAGES
THROUGH FRIDAY WITH ONLY A SLIGHT COOLDOWN TO SEASONAL AVERAGES ON
SATURDAY. WINDS SHOULD BE LIGHT AND EASTERLY AGAIN TODAY...WITH
SOME LOCATIONS BECOMING GUSTY IN THE AFTERNOON...ESPECIALLY NEAR
ANY SHOWER OR THUNDERSTORM. SUK

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  42  70  47 /  20  10  20  30
CTB  68  38  69  41 /   0   0  10  10
HLN  70  45  71  49 /  40  30  30  30
BZN  66  40  69  43 /  50  20  40  30
WEY  59  32  62  35 /  60  40  60  40
DLN  64  41  67  44 /  70  50  40  40
HVR  71  38  74  43 /   0   0  10  30
LWT  66  42  68  45 /   0  10  40  50

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 211611
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1011 AM MDT THU MAY 21 2015

.DISCUSSION...HAVE OPTED TO NOT MAKE ANY UPDATES THIS MORNING AS
THE GOING FORECAST APPEARS TO BE IN EXCELLENT SHAPE. SCATTERED
SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER SOUTHWEST AND SOUTH
CENTRAL MONTANA THIS AFTERNOON AND MOVE INTO SOUTHERN PORTIONS OF
CENTRAL MONTANA BY EVENING. CONVECTION WILL BE DRIVEN BY DIURNAL
INSTABILITY SO EXPECT THAT PRECIPITATION WILL TAPER OFF RAPIDLY
AFTER SUNSET. ALSO DO NOT EXPECT THAT ANY STORMS WILL BECOME
STRONG TO SEVERE AS INSTABILITY AND SHEAR ARE WEAK. HOWEVER, ANY
STORMS THAT DO FORM COULD PRODUCE SOME LOCALLY HEAVY RAIN. MPJ

&&

.AVIATION... UPDATED 1050Z. VFR CONDITIONS ARE ONCE AGAIN EXPECTED.
CLEAR SKIES TO A FEW CLOUDS AROUND 12000 FT CAN BE EXPECTED NEAR AND
NORTH OF A LINE FROM KLWT THROUGH KGTF. SOUTH OF THAT LINE EXPECT
ISOLATED SHOWERS THIS MORNING WITH SCATTERED SHOWERS BUT NUMEROUS
SHOWERS OVER THE MOUNTAINS THIS AFTERNOON. ALSO EXPECT SCATTERED
THUNDERSTORMS THIS AFTERNOON. GUSTY WINDS TO NEAR 40 KTS CAN BE
EXPECTED WITH A FEW OF THE THUNDERSTORMS. SHOWERS AND THUNDERSTORMS
WILL MOSTLY DISSIPATE NEAR AND AFTER MIDNIGHT. CONFIDENCE IN
FORECAST WINDS IS ABOVE AVERAGE. BLANK

&&

.PREV DISCUSSION...
/ISSUED 450 AM MDT THU MAY 21 2015/
THURSDAY THROUGH SATURDAY...
SHOWERS AND THUNDERSTORMS WILL BECOME MORE PREVALENT OVER THE NEXT
FEW DAYS AS MOISTURE FROM A LOW PRESSURE SYSTEM MOVING ACROSS THE
SOUTHERN US IS EJECTED UP INTO FROM THE SOUTH. THE SYSTEM LOOKS TO
STAY FAR ENOUGH TO THE SOUTH TO ELIMINATE THE CHANCE OF A
WIDESPREAD WETTING RAIN...INSTEAD AFTERNOON SHOWERS AND
THUNDERSTORMS LOOK TO DEVELOP EACH AFTERNOON AND SHOULD INCREASE
IN COVERAGE OF THE AREA THROUGH THE FIRST HALF OF THE WEEKEND.
RELATIVELY WEAK SHEAR WILL LIMIT THE CHANCES FOR ANY OF THE
SHOWERS OR THUNDERSTORMS TO DEVELOP INTO SEVERE STORMS...BUT
STRONG STORMS ARE POSSIBLE AND COULD PRODUCE SMALL HAIL AND GUSTY
WINDS ALONG WITH BRIEF HEAVY RAINFALL. MODELS SUGGEST THAT THERE
IS ENOUGH WIND ALOFT TO ALLOW FOR STORMS TO MOVE OFF OF ANY
INITIATION POINT AND THIS SHOULD LIMIT THE POTENTIAL FOR LONG
DURATION HEAVY RAINS FROM NEARLY STATIONARY STORMS. TEMPERATURES
ARE EXPECTED TO BE NEAR OR SLIGHTLY ABOVE SEASONAL AVERAGES
THROUGH FRIDAY WITH ONLY A SLIGHT COOLDOWN TO SEASONAL AVERAGES ON
SATURDAY. WINDS SHOULD BE LIGHT AND EASTERLY AGAIN TODAY...WITH
SOME LOCATIONS BECOMING GUSTY IN THE AFTERNOON...ESPECIALLY NEAR
ANY SHOWER OR THUNDERSTORM. SUK

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  42  70  47 /  20  10  20  30
CTB  68  38  69  41 /   0   0  10  10
HLN  70  45  71  49 /  40  30  30  30
BZN  66  40  69  43 /  50  20  40  30
WEY  59  32  62  35 /  60  40  60  40
DLN  64  41  67  44 /  70  50  40  40
HVR  71  38  74  43 /   0   0  10  30
LWT  66  42  68  45 /   0  10  40  50

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 211611
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1011 AM MDT THU MAY 21 2015

.DISCUSSION...HAVE OPTED TO NOT MAKE ANY UPDATES THIS MORNING AS
THE GOING FORECAST APPEARS TO BE IN EXCELLENT SHAPE. SCATTERED
SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER SOUTHWEST AND SOUTH
CENTRAL MONTANA THIS AFTERNOON AND MOVE INTO SOUTHERN PORTIONS OF
CENTRAL MONTANA BY EVENING. CONVECTION WILL BE DRIVEN BY DIURNAL
INSTABILITY SO EXPECT THAT PRECIPITATION WILL TAPER OFF RAPIDLY
AFTER SUNSET. ALSO DO NOT EXPECT THAT ANY STORMS WILL BECOME
STRONG TO SEVERE AS INSTABILITY AND SHEAR ARE WEAK. HOWEVER, ANY
STORMS THAT DO FORM COULD PRODUCE SOME LOCALLY HEAVY RAIN. MPJ

&&

.AVIATION... UPDATED 1050Z. VFR CONDITIONS ARE ONCE AGAIN EXPECTED.
CLEAR SKIES TO A FEW CLOUDS AROUND 12000 FT CAN BE EXPECTED NEAR AND
NORTH OF A LINE FROM KLWT THROUGH KGTF. SOUTH OF THAT LINE EXPECT
ISOLATED SHOWERS THIS MORNING WITH SCATTERED SHOWERS BUT NUMEROUS
SHOWERS OVER THE MOUNTAINS THIS AFTERNOON. ALSO EXPECT SCATTERED
THUNDERSTORMS THIS AFTERNOON. GUSTY WINDS TO NEAR 40 KTS CAN BE
EXPECTED WITH A FEW OF THE THUNDERSTORMS. SHOWERS AND THUNDERSTORMS
WILL MOSTLY DISSIPATE NEAR AND AFTER MIDNIGHT. CONFIDENCE IN
FORECAST WINDS IS ABOVE AVERAGE. BLANK

&&

.PREV DISCUSSION...
/ISSUED 450 AM MDT THU MAY 21 2015/
THURSDAY THROUGH SATURDAY...
SHOWERS AND THUNDERSTORMS WILL BECOME MORE PREVALENT OVER THE NEXT
FEW DAYS AS MOISTURE FROM A LOW PRESSURE SYSTEM MOVING ACROSS THE
SOUTHERN US IS EJECTED UP INTO FROM THE SOUTH. THE SYSTEM LOOKS TO
STAY FAR ENOUGH TO THE SOUTH TO ELIMINATE THE CHANCE OF A
WIDESPREAD WETTING RAIN...INSTEAD AFTERNOON SHOWERS AND
THUNDERSTORMS LOOK TO DEVELOP EACH AFTERNOON AND SHOULD INCREASE
IN COVERAGE OF THE AREA THROUGH THE FIRST HALF OF THE WEEKEND.
RELATIVELY WEAK SHEAR WILL LIMIT THE CHANCES FOR ANY OF THE
SHOWERS OR THUNDERSTORMS TO DEVELOP INTO SEVERE STORMS...BUT
STRONG STORMS ARE POSSIBLE AND COULD PRODUCE SMALL HAIL AND GUSTY
WINDS ALONG WITH BRIEF HEAVY RAINFALL. MODELS SUGGEST THAT THERE
IS ENOUGH WIND ALOFT TO ALLOW FOR STORMS TO MOVE OFF OF ANY
INITIATION POINT AND THIS SHOULD LIMIT THE POTENTIAL FOR LONG
DURATION HEAVY RAINS FROM NEARLY STATIONARY STORMS. TEMPERATURES
ARE EXPECTED TO BE NEAR OR SLIGHTLY ABOVE SEASONAL AVERAGES
THROUGH FRIDAY WITH ONLY A SLIGHT COOLDOWN TO SEASONAL AVERAGES ON
SATURDAY. WINDS SHOULD BE LIGHT AND EASTERLY AGAIN TODAY...WITH
SOME LOCATIONS BECOMING GUSTY IN THE AFTERNOON...ESPECIALLY NEAR
ANY SHOWER OR THUNDERSTORM. SUK

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  42  70  47 /  20  10  20  30
CTB  68  38  69  41 /   0   0  10  10
HLN  70  45  71  49 /  40  30  30  30
BZN  66  40  69  43 /  50  20  40  30
WEY  59  32  62  35 /  60  40  60  40
DLN  64  41  67  44 /  70  50  40  40
HVR  71  38  74  43 /   0   0  10  30
LWT  66  42  68  45 /   0  10  40  50

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 211611
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1011 AM MDT THU MAY 21 2015

.DISCUSSION...HAVE OPTED TO NOT MAKE ANY UPDATES THIS MORNING AS
THE GOING FORECAST APPEARS TO BE IN EXCELLENT SHAPE. SCATTERED
SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER SOUTHWEST AND SOUTH
CENTRAL MONTANA THIS AFTERNOON AND MOVE INTO SOUTHERN PORTIONS OF
CENTRAL MONTANA BY EVENING. CONVECTION WILL BE DRIVEN BY DIURNAL
INSTABILITY SO EXPECT THAT PRECIPITATION WILL TAPER OFF RAPIDLY
AFTER SUNSET. ALSO DO NOT EXPECT THAT ANY STORMS WILL BECOME
STRONG TO SEVERE AS INSTABILITY AND SHEAR ARE WEAK. HOWEVER, ANY
STORMS THAT DO FORM COULD PRODUCE SOME LOCALLY HEAVY RAIN. MPJ

&&

.AVIATION... UPDATED 1050Z. VFR CONDITIONS ARE ONCE AGAIN EXPECTED.
CLEAR SKIES TO A FEW CLOUDS AROUND 12000 FT CAN BE EXPECTED NEAR AND
NORTH OF A LINE FROM KLWT THROUGH KGTF. SOUTH OF THAT LINE EXPECT
ISOLATED SHOWERS THIS MORNING WITH SCATTERED SHOWERS BUT NUMEROUS
SHOWERS OVER THE MOUNTAINS THIS AFTERNOON. ALSO EXPECT SCATTERED
THUNDERSTORMS THIS AFTERNOON. GUSTY WINDS TO NEAR 40 KTS CAN BE
EXPECTED WITH A FEW OF THE THUNDERSTORMS. SHOWERS AND THUNDERSTORMS
WILL MOSTLY DISSIPATE NEAR AND AFTER MIDNIGHT. CONFIDENCE IN
FORECAST WINDS IS ABOVE AVERAGE. BLANK

&&

.PREV DISCUSSION...
/ISSUED 450 AM MDT THU MAY 21 2015/
THURSDAY THROUGH SATURDAY...
SHOWERS AND THUNDERSTORMS WILL BECOME MORE PREVALENT OVER THE NEXT
FEW DAYS AS MOISTURE FROM A LOW PRESSURE SYSTEM MOVING ACROSS THE
SOUTHERN US IS EJECTED UP INTO FROM THE SOUTH. THE SYSTEM LOOKS TO
STAY FAR ENOUGH TO THE SOUTH TO ELIMINATE THE CHANCE OF A
WIDESPREAD WETTING RAIN...INSTEAD AFTERNOON SHOWERS AND
THUNDERSTORMS LOOK TO DEVELOP EACH AFTERNOON AND SHOULD INCREASE
IN COVERAGE OF THE AREA THROUGH THE FIRST HALF OF THE WEEKEND.
RELATIVELY WEAK SHEAR WILL LIMIT THE CHANCES FOR ANY OF THE
SHOWERS OR THUNDERSTORMS TO DEVELOP INTO SEVERE STORMS...BUT
STRONG STORMS ARE POSSIBLE AND COULD PRODUCE SMALL HAIL AND GUSTY
WINDS ALONG WITH BRIEF HEAVY RAINFALL. MODELS SUGGEST THAT THERE
IS ENOUGH WIND ALOFT TO ALLOW FOR STORMS TO MOVE OFF OF ANY
INITIATION POINT AND THIS SHOULD LIMIT THE POTENTIAL FOR LONG
DURATION HEAVY RAINS FROM NEARLY STATIONARY STORMS. TEMPERATURES
ARE EXPECTED TO BE NEAR OR SLIGHTLY ABOVE SEASONAL AVERAGES
THROUGH FRIDAY WITH ONLY A SLIGHT COOLDOWN TO SEASONAL AVERAGES ON
SATURDAY. WINDS SHOULD BE LIGHT AND EASTERLY AGAIN TODAY...WITH
SOME LOCATIONS BECOMING GUSTY IN THE AFTERNOON...ESPECIALLY NEAR
ANY SHOWER OR THUNDERSTORM. SUK

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  42  70  47 /  20  10  20  30
CTB  68  38  69  41 /   0   0  10  10
HLN  70  45  71  49 /  40  30  30  30
BZN  66  40  69  43 /  50  20  40  30
WEY  59  32  62  35 /  60  40  60  40
DLN  64  41  67  44 /  70  50  40  40
HVR  71  38  74  43 /   0   0  10  30
LWT  66  42  68  45 /   0  10  40  50

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS




000
FXUS65 KGGW 211512
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
912 AM MDT THU MAY 21 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SATURDAY...

MORNING UPDATE...
NO CHANGES TO THE GOING FORECAST. IT CURRENTLY LOOKS TO BE
ON TRACK. HIGH PRESSURE IS IN PLACE ACROSS THE WESTERN HALF OF THE
CWA AT THE SURFACE WITH A LIGHT SOUTHEAST WIND SPIRALING OUT OF
IT. SKIES SHOULD REMAIN CLEAR THROUGH THE AFTERNOON WITH HIGHS
REACHING NEAR 70. GAH


PREVIOUS SHORT TERM DISCUSSION...
NORTHEAST MONTANA REMAINS UNDER A NARROW UPPER RIDGE THAT HAS
BROUGHT CLEAR SKIES AND RELATIVELY LIGHT WINDS FOR THE LAST COUPLE
OF DAYS. THIS RIDGE WILL PERSIST TODAY MAINTAINING MOSTLY CLEAR
SKIES. BUT THE SURFACE HIGH SHIFTS EAST. THIS WILL DEVELOP BRISK
SOUTHEAST WINDS THIS AFTERNOON AND EARLY EVENING. CURRENT MODELS
SUGGEST THAT WINDS WILL GENERALLY RUN JUST BELOW ADVISORY
CRITERIA. SO WILL LET THE NEXT SHIFT DECIDE ON THE UPDATE IF AN A
WIND ADVISORY IS NEEDED.

TONIGHT/FRIDAY...A CLOSED LOW OFF THE SOUTHERN CALIFORNIA COAST
WILL BEGIN TO LIFT INTO THE GREAT BASIN REGION TO SEND MOISTURE
FURTHER NORTH INTO OUR AREA. THIS WILL INCREASE SKY COVER FROM THE
SOUTH. BY AFTERNOON INSTABILITY INCREASES OVER OUR WEST WITH WEAK
TO MODERATE CAPE AND NEGATIVE LI. THIS COULD LEAD TO ISOLATED
THUNDERSTORMS. SOUTHEAST WINDS LOOK TO BE STRONGER...ENOUGH FOR A
LIKELY ADVISORY FOR FORT PECK LAKE.

FRIDAY NIGHT AND SATURDAY...THE CLOSED UPPER LOW MOVES ACROSS THE
CENTRAL ROCKIES AND SHOWS SIGNS OF STACKING UP WITH A CLOSED
SURFACE LOW. THIS SHOULD KEEP MOST OF THE ENERGY TO OUR SOUTH.
HOWEVER CONTINUED UNSTABLE CONDITIONS COULD RESULT IN MORE
ISOLATED THUNDER. EXPECT BRISK EAST WINDS TO DEVELOP AGAIN.

FLOW ALOFT WILL NOT BE STRONG FROM ANY DIRECTION DURING THE
PERIOD. SO DO NOT EXPECT ANY WARM AIR SURGING IN. THEREFORE
TEMPERATURES WILL RUN CLOSE TO OR SLIGHTLY ABOVE NORMAL.

SCT


.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
SATURDAY NIGHT AND SUNDAY FEATURES A BROAD UPPER TROUGH OVER THE
WEST AND AN UPPER RIDGE TO EAST OF NORTHEAST MONTANA. THE TROUGH
WILL LIFT NORTH INTO MONTANA AND NORTH DAKOTA BY MONDAY. THEN...THE
FLOW PATTERN ALOFT OVER MONTANA WILL BE WEAK...VARIABLE AND UN-
FOCUSED MONDAY AND TUESDAY. THE SOUTHEAST HALF OF THE FORECAST
AREA HAS A BETTER CHANCE OF SEEING SHOWERS MAYBE THUNDERSTORMS AT
TIMES BETWEEN SATURDAY NIGHT AND MONDAY WHERE THE DEEPER MOISTURE
IS EXPECTED.

MODEL DIFFERENCES SHOW UP TUESDAY AND BEYOND AS GFS HAS A NW FLOW
ALOFT WITH A BACK DOOR COLD FRONT ON WEDNESDAY. ECMWF HAS AN UPPER
TROUGH OVER THE PACIFIC NW ON TUESDAY THAT EVENTUALLY MOVES EAST
ACROSS MONTANA WEDNESDAY AND THURSDAY. WILL MAINTAIN A
CHANCE/SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR NOW.  FORRESTER


&&

.AVIATION...
VFR.

MAINLY CLEAR SKIES TODAY AND TONIGHT. LIGHT MAINLY EAST WINDS THIS
MORNING WILL BECOME SOUTHEAST 10 TO 20 KNOTS THIS AFTERNOON. EAST
WINDS WILL CONTINUE AROUND 10 KNOTS TONIGHT.


&&

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


&&

$$

WEATHER.GOV/GLASGOW






000
FXUS65 KGGW 211512
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
912 AM MDT THU MAY 21 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SATURDAY...

MORNING UPDATE...
NO CHANGES TO THE GOING FORECAST. IT CURRENTLY LOOKS TO BE
ON TRACK. HIGH PRESSURE IS IN PLACE ACROSS THE WESTERN HALF OF THE
CWA AT THE SURFACE WITH A LIGHT SOUTHEAST WIND SPIRALING OUT OF
IT. SKIES SHOULD REMAIN CLEAR THROUGH THE AFTERNOON WITH HIGHS
REACHING NEAR 70. GAH


PREVIOUS SHORT TERM DISCUSSION...
NORTHEAST MONTANA REMAINS UNDER A NARROW UPPER RIDGE THAT HAS
BROUGHT CLEAR SKIES AND RELATIVELY LIGHT WINDS FOR THE LAST COUPLE
OF DAYS. THIS RIDGE WILL PERSIST TODAY MAINTAINING MOSTLY CLEAR
SKIES. BUT THE SURFACE HIGH SHIFTS EAST. THIS WILL DEVELOP BRISK
SOUTHEAST WINDS THIS AFTERNOON AND EARLY EVENING. CURRENT MODELS
SUGGEST THAT WINDS WILL GENERALLY RUN JUST BELOW ADVISORY
CRITERIA. SO WILL LET THE NEXT SHIFT DECIDE ON THE UPDATE IF AN A
WIND ADVISORY IS NEEDED.

TONIGHT/FRIDAY...A CLOSED LOW OFF THE SOUTHERN CALIFORNIA COAST
WILL BEGIN TO LIFT INTO THE GREAT BASIN REGION TO SEND MOISTURE
FURTHER NORTH INTO OUR AREA. THIS WILL INCREASE SKY COVER FROM THE
SOUTH. BY AFTERNOON INSTABILITY INCREASES OVER OUR WEST WITH WEAK
TO MODERATE CAPE AND NEGATIVE LI. THIS COULD LEAD TO ISOLATED
THUNDERSTORMS. SOUTHEAST WINDS LOOK TO BE STRONGER...ENOUGH FOR A
LIKELY ADVISORY FOR FORT PECK LAKE.

FRIDAY NIGHT AND SATURDAY...THE CLOSED UPPER LOW MOVES ACROSS THE
CENTRAL ROCKIES AND SHOWS SIGNS OF STACKING UP WITH A CLOSED
SURFACE LOW. THIS SHOULD KEEP MOST OF THE ENERGY TO OUR SOUTH.
HOWEVER CONTINUED UNSTABLE CONDITIONS COULD RESULT IN MORE
ISOLATED THUNDER. EXPECT BRISK EAST WINDS TO DEVELOP AGAIN.

FLOW ALOFT WILL NOT BE STRONG FROM ANY DIRECTION DURING THE
PERIOD. SO DO NOT EXPECT ANY WARM AIR SURGING IN. THEREFORE
TEMPERATURES WILL RUN CLOSE TO OR SLIGHTLY ABOVE NORMAL.

SCT


.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
SATURDAY NIGHT AND SUNDAY FEATURES A BROAD UPPER TROUGH OVER THE
WEST AND AN UPPER RIDGE TO EAST OF NORTHEAST MONTANA. THE TROUGH
WILL LIFT NORTH INTO MONTANA AND NORTH DAKOTA BY MONDAY. THEN...THE
FLOW PATTERN ALOFT OVER MONTANA WILL BE WEAK...VARIABLE AND UN-
FOCUSED MONDAY AND TUESDAY. THE SOUTHEAST HALF OF THE FORECAST
AREA HAS A BETTER CHANCE OF SEEING SHOWERS MAYBE THUNDERSTORMS AT
TIMES BETWEEN SATURDAY NIGHT AND MONDAY WHERE THE DEEPER MOISTURE
IS EXPECTED.

MODEL DIFFERENCES SHOW UP TUESDAY AND BEYOND AS GFS HAS A NW FLOW
ALOFT WITH A BACK DOOR COLD FRONT ON WEDNESDAY. ECMWF HAS AN UPPER
TROUGH OVER THE PACIFIC NW ON TUESDAY THAT EVENTUALLY MOVES EAST
ACROSS MONTANA WEDNESDAY AND THURSDAY. WILL MAINTAIN A
CHANCE/SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR NOW.  FORRESTER


&&

.AVIATION...
VFR.

MAINLY CLEAR SKIES TODAY AND TONIGHT. LIGHT MAINLY EAST WINDS THIS
MORNING WILL BECOME SOUTHEAST 10 TO 20 KNOTS THIS AFTERNOON. EAST
WINDS WILL CONTINUE AROUND 10 KNOTS TONIGHT.


&&

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


&&

$$

WEATHER.GOV/GLASGOW






000
FXUS65 KGGW 211512
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
912 AM MDT THU MAY 21 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SATURDAY...

MORNING UPDATE...
NO CHANGES TO THE GOING FORECAST. IT CURRENTLY LOOKS TO BE
ON TRACK. HIGH PRESSURE IS IN PLACE ACROSS THE WESTERN HALF OF THE
CWA AT THE SURFACE WITH A LIGHT SOUTHEAST WIND SPIRALING OUT OF
IT. SKIES SHOULD REMAIN CLEAR THROUGH THE AFTERNOON WITH HIGHS
REACHING NEAR 70. GAH


PREVIOUS SHORT TERM DISCUSSION...
NORTHEAST MONTANA REMAINS UNDER A NARROW UPPER RIDGE THAT HAS
BROUGHT CLEAR SKIES AND RELATIVELY LIGHT WINDS FOR THE LAST COUPLE
OF DAYS. THIS RIDGE WILL PERSIST TODAY MAINTAINING MOSTLY CLEAR
SKIES. BUT THE SURFACE HIGH SHIFTS EAST. THIS WILL DEVELOP BRISK
SOUTHEAST WINDS THIS AFTERNOON AND EARLY EVENING. CURRENT MODELS
SUGGEST THAT WINDS WILL GENERALLY RUN JUST BELOW ADVISORY
CRITERIA. SO WILL LET THE NEXT SHIFT DECIDE ON THE UPDATE IF AN A
WIND ADVISORY IS NEEDED.

TONIGHT/FRIDAY...A CLOSED LOW OFF THE SOUTHERN CALIFORNIA COAST
WILL BEGIN TO LIFT INTO THE GREAT BASIN REGION TO SEND MOISTURE
FURTHER NORTH INTO OUR AREA. THIS WILL INCREASE SKY COVER FROM THE
SOUTH. BY AFTERNOON INSTABILITY INCREASES OVER OUR WEST WITH WEAK
TO MODERATE CAPE AND NEGATIVE LI. THIS COULD LEAD TO ISOLATED
THUNDERSTORMS. SOUTHEAST WINDS LOOK TO BE STRONGER...ENOUGH FOR A
LIKELY ADVISORY FOR FORT PECK LAKE.

FRIDAY NIGHT AND SATURDAY...THE CLOSED UPPER LOW MOVES ACROSS THE
CENTRAL ROCKIES AND SHOWS SIGNS OF STACKING UP WITH A CLOSED
SURFACE LOW. THIS SHOULD KEEP MOST OF THE ENERGY TO OUR SOUTH.
HOWEVER CONTINUED UNSTABLE CONDITIONS COULD RESULT IN MORE
ISOLATED THUNDER. EXPECT BRISK EAST WINDS TO DEVELOP AGAIN.

FLOW ALOFT WILL NOT BE STRONG FROM ANY DIRECTION DURING THE
PERIOD. SO DO NOT EXPECT ANY WARM AIR SURGING IN. THEREFORE
TEMPERATURES WILL RUN CLOSE TO OR SLIGHTLY ABOVE NORMAL.

SCT


.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
SATURDAY NIGHT AND SUNDAY FEATURES A BROAD UPPER TROUGH OVER THE
WEST AND AN UPPER RIDGE TO EAST OF NORTHEAST MONTANA. THE TROUGH
WILL LIFT NORTH INTO MONTANA AND NORTH DAKOTA BY MONDAY. THEN...THE
FLOW PATTERN ALOFT OVER MONTANA WILL BE WEAK...VARIABLE AND UN-
FOCUSED MONDAY AND TUESDAY. THE SOUTHEAST HALF OF THE FORECAST
AREA HAS A BETTER CHANCE OF SEEING SHOWERS MAYBE THUNDERSTORMS AT
TIMES BETWEEN SATURDAY NIGHT AND MONDAY WHERE THE DEEPER MOISTURE
IS EXPECTED.

MODEL DIFFERENCES SHOW UP TUESDAY AND BEYOND AS GFS HAS A NW FLOW
ALOFT WITH A BACK DOOR COLD FRONT ON WEDNESDAY. ECMWF HAS AN UPPER
TROUGH OVER THE PACIFIC NW ON TUESDAY THAT EVENTUALLY MOVES EAST
ACROSS MONTANA WEDNESDAY AND THURSDAY. WILL MAINTAIN A
CHANCE/SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR NOW.  FORRESTER


&&

.AVIATION...
VFR.

MAINLY CLEAR SKIES TODAY AND TONIGHT. LIGHT MAINLY EAST WINDS THIS
MORNING WILL BECOME SOUTHEAST 10 TO 20 KNOTS THIS AFTERNOON. EAST
WINDS WILL CONTINUE AROUND 10 KNOTS TONIGHT.


&&

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


&&

$$

WEATHER.GOV/GLASGOW






000
FXUS65 KGGW 211512
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
912 AM MDT THU MAY 21 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SATURDAY...

MORNING UPDATE...
NO CHANGES TO THE GOING FORECAST. IT CURRENTLY LOOKS TO BE
ON TRACK. HIGH PRESSURE IS IN PLACE ACROSS THE WESTERN HALF OF THE
CWA AT THE SURFACE WITH A LIGHT SOUTHEAST WIND SPIRALING OUT OF
IT. SKIES SHOULD REMAIN CLEAR THROUGH THE AFTERNOON WITH HIGHS
REACHING NEAR 70. GAH


PREVIOUS SHORT TERM DISCUSSION...
NORTHEAST MONTANA REMAINS UNDER A NARROW UPPER RIDGE THAT HAS
BROUGHT CLEAR SKIES AND RELATIVELY LIGHT WINDS FOR THE LAST COUPLE
OF DAYS. THIS RIDGE WILL PERSIST TODAY MAINTAINING MOSTLY CLEAR
SKIES. BUT THE SURFACE HIGH SHIFTS EAST. THIS WILL DEVELOP BRISK
SOUTHEAST WINDS THIS AFTERNOON AND EARLY EVENING. CURRENT MODELS
SUGGEST THAT WINDS WILL GENERALLY RUN JUST BELOW ADVISORY
CRITERIA. SO WILL LET THE NEXT SHIFT DECIDE ON THE UPDATE IF AN A
WIND ADVISORY IS NEEDED.

TONIGHT/FRIDAY...A CLOSED LOW OFF THE SOUTHERN CALIFORNIA COAST
WILL BEGIN TO LIFT INTO THE GREAT BASIN REGION TO SEND MOISTURE
FURTHER NORTH INTO OUR AREA. THIS WILL INCREASE SKY COVER FROM THE
SOUTH. BY AFTERNOON INSTABILITY INCREASES OVER OUR WEST WITH WEAK
TO MODERATE CAPE AND NEGATIVE LI. THIS COULD LEAD TO ISOLATED
THUNDERSTORMS. SOUTHEAST WINDS LOOK TO BE STRONGER...ENOUGH FOR A
LIKELY ADVISORY FOR FORT PECK LAKE.

FRIDAY NIGHT AND SATURDAY...THE CLOSED UPPER LOW MOVES ACROSS THE
CENTRAL ROCKIES AND SHOWS SIGNS OF STACKING UP WITH A CLOSED
SURFACE LOW. THIS SHOULD KEEP MOST OF THE ENERGY TO OUR SOUTH.
HOWEVER CONTINUED UNSTABLE CONDITIONS COULD RESULT IN MORE
ISOLATED THUNDER. EXPECT BRISK EAST WINDS TO DEVELOP AGAIN.

FLOW ALOFT WILL NOT BE STRONG FROM ANY DIRECTION DURING THE
PERIOD. SO DO NOT EXPECT ANY WARM AIR SURGING IN. THEREFORE
TEMPERATURES WILL RUN CLOSE TO OR SLIGHTLY ABOVE NORMAL.

SCT


.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
SATURDAY NIGHT AND SUNDAY FEATURES A BROAD UPPER TROUGH OVER THE
WEST AND AN UPPER RIDGE TO EAST OF NORTHEAST MONTANA. THE TROUGH
WILL LIFT NORTH INTO MONTANA AND NORTH DAKOTA BY MONDAY. THEN...THE
FLOW PATTERN ALOFT OVER MONTANA WILL BE WEAK...VARIABLE AND UN-
FOCUSED MONDAY AND TUESDAY. THE SOUTHEAST HALF OF THE FORECAST
AREA HAS A BETTER CHANCE OF SEEING SHOWERS MAYBE THUNDERSTORMS AT
TIMES BETWEEN SATURDAY NIGHT AND MONDAY WHERE THE DEEPER MOISTURE
IS EXPECTED.

MODEL DIFFERENCES SHOW UP TUESDAY AND BEYOND AS GFS HAS A NW FLOW
ALOFT WITH A BACK DOOR COLD FRONT ON WEDNESDAY. ECMWF HAS AN UPPER
TROUGH OVER THE PACIFIC NW ON TUESDAY THAT EVENTUALLY MOVES EAST
ACROSS MONTANA WEDNESDAY AND THURSDAY. WILL MAINTAIN A
CHANCE/SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR NOW.  FORRESTER


&&

.AVIATION...
VFR.

MAINLY CLEAR SKIES TODAY AND TONIGHT. LIGHT MAINLY EAST WINDS THIS
MORNING WILL BECOME SOUTHEAST 10 TO 20 KNOTS THIS AFTERNOON. EAST
WINDS WILL CONTINUE AROUND 10 KNOTS TONIGHT.


&&

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


&&

$$

WEATHER.GOV/GLASGOW






000
FXUS65 KGGW 211512
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
912 AM MDT THU MAY 21 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SATURDAY...

MORNING UPDATE...
NO CHANGES TO THE GOING FORECAST. IT CURRENTLY LOOKS TO BE
ON TRACK. HIGH PRESSURE IS IN PLACE ACROSS THE WESTERN HALF OF THE
CWA AT THE SURFACE WITH A LIGHT SOUTHEAST WIND SPIRALING OUT OF
IT. SKIES SHOULD REMAIN CLEAR THROUGH THE AFTERNOON WITH HIGHS
REACHING NEAR 70. GAH


PREVIOUS SHORT TERM DISCUSSION...
NORTHEAST MONTANA REMAINS UNDER A NARROW UPPER RIDGE THAT HAS
BROUGHT CLEAR SKIES AND RELATIVELY LIGHT WINDS FOR THE LAST COUPLE
OF DAYS. THIS RIDGE WILL PERSIST TODAY MAINTAINING MOSTLY CLEAR
SKIES. BUT THE SURFACE HIGH SHIFTS EAST. THIS WILL DEVELOP BRISK
SOUTHEAST WINDS THIS AFTERNOON AND EARLY EVENING. CURRENT MODELS
SUGGEST THAT WINDS WILL GENERALLY RUN JUST BELOW ADVISORY
CRITERIA. SO WILL LET THE NEXT SHIFT DECIDE ON THE UPDATE IF AN A
WIND ADVISORY IS NEEDED.

TONIGHT/FRIDAY...A CLOSED LOW OFF THE SOUTHERN CALIFORNIA COAST
WILL BEGIN TO LIFT INTO THE GREAT BASIN REGION TO SEND MOISTURE
FURTHER NORTH INTO OUR AREA. THIS WILL INCREASE SKY COVER FROM THE
SOUTH. BY AFTERNOON INSTABILITY INCREASES OVER OUR WEST WITH WEAK
TO MODERATE CAPE AND NEGATIVE LI. THIS COULD LEAD TO ISOLATED
THUNDERSTORMS. SOUTHEAST WINDS LOOK TO BE STRONGER...ENOUGH FOR A
LIKELY ADVISORY FOR FORT PECK LAKE.

FRIDAY NIGHT AND SATURDAY...THE CLOSED UPPER LOW MOVES ACROSS THE
CENTRAL ROCKIES AND SHOWS SIGNS OF STACKING UP WITH A CLOSED
SURFACE LOW. THIS SHOULD KEEP MOST OF THE ENERGY TO OUR SOUTH.
HOWEVER CONTINUED UNSTABLE CONDITIONS COULD RESULT IN MORE
ISOLATED THUNDER. EXPECT BRISK EAST WINDS TO DEVELOP AGAIN.

FLOW ALOFT WILL NOT BE STRONG FROM ANY DIRECTION DURING THE
PERIOD. SO DO NOT EXPECT ANY WARM AIR SURGING IN. THEREFORE
TEMPERATURES WILL RUN CLOSE TO OR SLIGHTLY ABOVE NORMAL.

SCT


.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
SATURDAY NIGHT AND SUNDAY FEATURES A BROAD UPPER TROUGH OVER THE
WEST AND AN UPPER RIDGE TO EAST OF NORTHEAST MONTANA. THE TROUGH
WILL LIFT NORTH INTO MONTANA AND NORTH DAKOTA BY MONDAY. THEN...THE
FLOW PATTERN ALOFT OVER MONTANA WILL BE WEAK...VARIABLE AND UN-
FOCUSED MONDAY AND TUESDAY. THE SOUTHEAST HALF OF THE FORECAST
AREA HAS A BETTER CHANCE OF SEEING SHOWERS MAYBE THUNDERSTORMS AT
TIMES BETWEEN SATURDAY NIGHT AND MONDAY WHERE THE DEEPER MOISTURE
IS EXPECTED.

MODEL DIFFERENCES SHOW UP TUESDAY AND BEYOND AS GFS HAS A NW FLOW
ALOFT WITH A BACK DOOR COLD FRONT ON WEDNESDAY. ECMWF HAS AN UPPER
TROUGH OVER THE PACIFIC NW ON TUESDAY THAT EVENTUALLY MOVES EAST
ACROSS MONTANA WEDNESDAY AND THURSDAY. WILL MAINTAIN A
CHANCE/SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR NOW.  FORRESTER


&&

.AVIATION...
VFR.

MAINLY CLEAR SKIES TODAY AND TONIGHT. LIGHT MAINLY EAST WINDS THIS
MORNING WILL BECOME SOUTHEAST 10 TO 20 KNOTS THIS AFTERNOON. EAST
WINDS WILL CONTINUE AROUND 10 KNOTS TONIGHT.


&&

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


&&

$$

WEATHER.GOV/GLASGOW





000
FXUS65 KGGW 211512
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
912 AM MDT THU MAY 21 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SATURDAY...

MORNING UPDATE...
NO CHANGES TO THE GOING FORECAST. IT CURRENTLY LOOKS TO BE
ON TRACK. HIGH PRESSURE IS IN PLACE ACROSS THE WESTERN HALF OF THE
CWA AT THE SURFACE WITH A LIGHT SOUTHEAST WIND SPIRALING OUT OF
IT. SKIES SHOULD REMAIN CLEAR THROUGH THE AFTERNOON WITH HIGHS
REACHING NEAR 70. GAH


PREVIOUS SHORT TERM DISCUSSION...
NORTHEAST MONTANA REMAINS UNDER A NARROW UPPER RIDGE THAT HAS
BROUGHT CLEAR SKIES AND RELATIVELY LIGHT WINDS FOR THE LAST COUPLE
OF DAYS. THIS RIDGE WILL PERSIST TODAY MAINTAINING MOSTLY CLEAR
SKIES. BUT THE SURFACE HIGH SHIFTS EAST. THIS WILL DEVELOP BRISK
SOUTHEAST WINDS THIS AFTERNOON AND EARLY EVENING. CURRENT MODELS
SUGGEST THAT WINDS WILL GENERALLY RUN JUST BELOW ADVISORY
CRITERIA. SO WILL LET THE NEXT SHIFT DECIDE ON THE UPDATE IF AN A
WIND ADVISORY IS NEEDED.

TONIGHT/FRIDAY...A CLOSED LOW OFF THE SOUTHERN CALIFORNIA COAST
WILL BEGIN TO LIFT INTO THE GREAT BASIN REGION TO SEND MOISTURE
FURTHER NORTH INTO OUR AREA. THIS WILL INCREASE SKY COVER FROM THE
SOUTH. BY AFTERNOON INSTABILITY INCREASES OVER OUR WEST WITH WEAK
TO MODERATE CAPE AND NEGATIVE LI. THIS COULD LEAD TO ISOLATED
THUNDERSTORMS. SOUTHEAST WINDS LOOK TO BE STRONGER...ENOUGH FOR A
LIKELY ADVISORY FOR FORT PECK LAKE.

FRIDAY NIGHT AND SATURDAY...THE CLOSED UPPER LOW MOVES ACROSS THE
CENTRAL ROCKIES AND SHOWS SIGNS OF STACKING UP WITH A CLOSED
SURFACE LOW. THIS SHOULD KEEP MOST OF THE ENERGY TO OUR SOUTH.
HOWEVER CONTINUED UNSTABLE CONDITIONS COULD RESULT IN MORE
ISOLATED THUNDER. EXPECT BRISK EAST WINDS TO DEVELOP AGAIN.

FLOW ALOFT WILL NOT BE STRONG FROM ANY DIRECTION DURING THE
PERIOD. SO DO NOT EXPECT ANY WARM AIR SURGING IN. THEREFORE
TEMPERATURES WILL RUN CLOSE TO OR SLIGHTLY ABOVE NORMAL.

SCT


.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
SATURDAY NIGHT AND SUNDAY FEATURES A BROAD UPPER TROUGH OVER THE
WEST AND AN UPPER RIDGE TO EAST OF NORTHEAST MONTANA. THE TROUGH
WILL LIFT NORTH INTO MONTANA AND NORTH DAKOTA BY MONDAY. THEN...THE
FLOW PATTERN ALOFT OVER MONTANA WILL BE WEAK...VARIABLE AND UN-
FOCUSED MONDAY AND TUESDAY. THE SOUTHEAST HALF OF THE FORECAST
AREA HAS A BETTER CHANCE OF SEEING SHOWERS MAYBE THUNDERSTORMS AT
TIMES BETWEEN SATURDAY NIGHT AND MONDAY WHERE THE DEEPER MOISTURE
IS EXPECTED.

MODEL DIFFERENCES SHOW UP TUESDAY AND BEYOND AS GFS HAS A NW FLOW
ALOFT WITH A BACK DOOR COLD FRONT ON WEDNESDAY. ECMWF HAS AN UPPER
TROUGH OVER THE PACIFIC NW ON TUESDAY THAT EVENTUALLY MOVES EAST
ACROSS MONTANA WEDNESDAY AND THURSDAY. WILL MAINTAIN A
CHANCE/SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR NOW.  FORRESTER


&&

.AVIATION...
VFR.

MAINLY CLEAR SKIES TODAY AND TONIGHT. LIGHT MAINLY EAST WINDS THIS
MORNING WILL BECOME SOUTHEAST 10 TO 20 KNOTS THIS AFTERNOON. EAST
WINDS WILL CONTINUE AROUND 10 KNOTS TONIGHT.


&&

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


&&

$$

WEATHER.GOV/GLASGOW






000
FXUS65 KBYZ 211441
AFDBYZ

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
841 AM MDT THU MAY 21 2015

.UPDATE...
JUST A FEW MINOR TWEAKS TO THE FORECAST FOR THE MORNING UPDATE.
REMOVED POPS FROM THE BIG HORNS FOR THE MORNING AND REDUCED THEM A
BIT ON THE EAST SECTIONS OF THE BEARTOOTHS. REST OF FORECAST IN
GOOD SHAPE. BT

&&

.SHORT TERM...VALID FOR TDY AND FRI...

WEAK FLOW ALOFT WITH DRIER AIR HAVING BEEN PUSHED INTO THE EASTERN
HALF OF THE AREA BY A CUTOFF RIDGE OVER SOUTHERN CANADA. LOW ALONG
THE CALIFORNIA COAST IS GOING TO DIG A BIT MORE THAN PREVIOUSLY
EXPECTED TODAY AND THIS MEANS THE REGION WILL SEE ONLY AN
INCREMENTAL CHANGE IN THE WEATHER. MOST OF THE REGION WILL BE DRY
BUT ENOUGH MOISTURE WILL BE PUSHED INTO THE SOUTHWEST MOUNTAINS
FOR LOW CHANCE OF SHOWERS. DID LOWER POPS FOR THE FOOTHILLS LATE
TODAY AND OVERNIGHT AS GFS AND ECMWF INDICATE THE MOISTURE WILL
UNLIKELY TRAVEL OFF OF THE HIGHER TERRAIN. OVER THE PLAINS LOW
LEVEL FLOW REMAINS EASTERLY BUT DOES TREND A BIT TOWARDS
SOUTHEASTERLY WHICH WILL WEAKEN THE UPSLOPE COMPONENT A BIT AND
SUPPORT WARMER TEMPERATURES.

FRIDAY THE UPPER LOW MOVES ACROSS CALIFORNIA TOWARDS THE SOUTHERN
GREAT BASIN AND STRONGER MID LEVEL WINDS TRANSLATING DOWNSTREAM
CAUSE FALLING SURFACE PRESSURES ALONG THE COLORADO FRONT RANGE.
WHILE FLOW ALOFT OVER MONTANA AND NORTHERN WYOMING REMAIN WEAK
MOISTURE IS MOVING NORTHWARD ESPECIALLY AS THE CANADIAN RIDGE
LOSES THE ABILITY TO PUSH DRIER AIR OUT INTO THE AREA.
PRECIPITABLE WATERS INCREASING WILL SUPPORT BETTER MOISTURE FOR
DEEP CONVECTION WITH THE TEMPERATURES WARMING UP INTO THE 70S.
EXPECT SHOWERS AND THUNDERSTORMS TO MOVE OFF OF THE HIGHER
TERRAIN...ESPECIALLY AS A WEAK LOBE OF ENERGY MOVES THROUGH THE
AREA FRIDAY NIGHT. DID RAISE POPS OVER SOUTHEAST MONTANA TO
INDICATE BETTER CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS.
BORSUM

.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...

KEPT THE EXISTING LONG TERM FORECAST IN TACT AND JUST MADE SOME
SMALL ADJUSTMENTS HERE AND THERE TO POPS. THE MAIN FOCUS WAS TO
BUMP POPS UP OVER THE EAST FOR SATURDAY NIGHT THROUGH THE DAY
SUNDAY. MODELS WERE CONSISTENTLY BRINGING THE NORTHERN PART OF A
STRETCHED OUT UPPER LOW INTO NORTHEAST WYOMING SATURDAY NIGHT AND
SLOWLY TRACKING INTO NORTHEAST INTO NORTH DAKOTA ON SUNDAY.
PERSISTENT EAST TO SOUTHEAST SURFACE WINDS WILL ALLOW PRECIPITABLE
WATER AMOUNTS OF AROUND AN INCH TO MOVE INTO SOUTHEAST MONTANA.
ATMOSHPERE NOT EXPECTED TO BE TERRIBLY UNSTABLE...BUT WITH DEEP
MOISTURE AND WEAK STEERING WINDS...COULD HAVE SHOWERS WITH HEAVY
RAIN.

THE NEXT SYSTEM TO IMPACT THE AREA WILL BE ON TUESDAY. AN UPPER
LOW OVER WESTERN BRITISH COLUMBIA DROPS SOUTHEAST INTO WASHINGTON
ON MONDAY. ENERGY OUT AHEAD OF THIS LOW WILL KICK ACROSS WESTERN
AND CENTRAL ZONES ON TUESDAY. BOTH ECMWF AND THE GFS WERE SHOWING
THIS. THIS WILL LIKELY BE THE BEST CHANCE OF GETTING SHOWERS INTO
THE BILLINGS AREA. SHOWERS OVER THE WEEKEND WILL LIKELY BE TIED TO
THE TERRAIN AND WEAK STEERING WINDS WILL CAUSE TROUBLE FOR THE
SHOWERS IN THEIR ATTEMPT TO MOVE OFF THE FOOTHILLS. TEMPERATURES
WILL BE SEASONAL WITH LOW LEVEL EAST WINDS. TWH
&&

.AVIATION...

CLOUDS WILL INCREASE OVER THE SOUTHWEST MOUNTAINS TODAY WITH A
WEAK SYSTEM IN SOUTHERN IDAHO SLOWLY APPROACHING WESTERN MONTANA.
A FEW SHOWERS WILL DEVELOP OVER THE BEARTOOTH/ABSAROKA MOUNTAINS
BY EARLY AFTERNOON. CONDITIONS WILL REAMIN VFR...BUT LOCAL MVFR
CONDITIONS ARE POSSIBLE IN HEAVIER SHOWERS FROM KLVM SOUTHWARD.
MOUNTAINS WILL BE PARTIALLY OBSCURED...ESPECIALLY THIS AFTERNOON
IN SHOWERS. TWH/AAG

&&

.PRELIMINARY POINT TEMP/POPS...

    TDY FRI     SAT     SUN     MON     TUE     WED
-------------------------------------------------------
BIL 067 044/071 046/064 045/062 045/070 048/069 048/070
    0/B 02/T    43/T    33/T    32/T    23/T    33/T
LVM 064 040/067 043/062 042/062 039/067 043/065 042/069
    2/T 24/T    44/T    43/T    33/T    34/T    44/T
HDN 070 044/073 045/066 045/063 045/071 048/071 047/073
    0/U 02/T    33/T    33/T    32/T    23/T    33/T
MLS 070 045/072 046/065 047/063 047/069 048/071 049/072
    0/U 02/T    23/T    44/T    43/T    22/T    23/T
4BQ 067 043/068 044/061 047/059 044/067 046/069 047/069
    0/U 02/T    24/T    56/T    43/T    23/T    33/T
BHK 068 041/068 042/060 045/060 044/065 044/069 045/067
    0/U 01/N    24/T    56/T    55/T    32/T    33/T
SHR 064 041/065 041/060 043/058 040/067 043/066 043/068
    0/B 13/T    34/T    44/T    32/T    24/T    43/T

&&

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

&&

$$
WEATHER.GOV/BILLINGS



000
FXUS65 KBYZ 211441
AFDBYZ

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
841 AM MDT THU MAY 21 2015

.UPDATE...
JUST A FEW MINOR TWEAKS TO THE FORECAST FOR THE MORNING UPDATE.
REMOVED POPS FROM THE BIG HORNS FOR THE MORNING AND REDUCED THEM A
BIT ON THE EAST SECTIONS OF THE BEARTOOTHS. REST OF FORECAST IN
GOOD SHAPE. BT

&&

.SHORT TERM...VALID FOR TDY AND FRI...

WEAK FLOW ALOFT WITH DRIER AIR HAVING BEEN PUSHED INTO THE EASTERN
HALF OF THE AREA BY A CUTOFF RIDGE OVER SOUTHERN CANADA. LOW ALONG
THE CALIFORNIA COAST IS GOING TO DIG A BIT MORE THAN PREVIOUSLY
EXPECTED TODAY AND THIS MEANS THE REGION WILL SEE ONLY AN
INCREMENTAL CHANGE IN THE WEATHER. MOST OF THE REGION WILL BE DRY
BUT ENOUGH MOISTURE WILL BE PUSHED INTO THE SOUTHWEST MOUNTAINS
FOR LOW CHANCE OF SHOWERS. DID LOWER POPS FOR THE FOOTHILLS LATE
TODAY AND OVERNIGHT AS GFS AND ECMWF INDICATE THE MOISTURE WILL
UNLIKELY TRAVEL OFF OF THE HIGHER TERRAIN. OVER THE PLAINS LOW
LEVEL FLOW REMAINS EASTERLY BUT DOES TREND A BIT TOWARDS
SOUTHEASTERLY WHICH WILL WEAKEN THE UPSLOPE COMPONENT A BIT AND
SUPPORT WARMER TEMPERATURES.

FRIDAY THE UPPER LOW MOVES ACROSS CALIFORNIA TOWARDS THE SOUTHERN
GREAT BASIN AND STRONGER MID LEVEL WINDS TRANSLATING DOWNSTREAM
CAUSE FALLING SURFACE PRESSURES ALONG THE COLORADO FRONT RANGE.
WHILE FLOW ALOFT OVER MONTANA AND NORTHERN WYOMING REMAIN WEAK
MOISTURE IS MOVING NORTHWARD ESPECIALLY AS THE CANADIAN RIDGE
LOSES THE ABILITY TO PUSH DRIER AIR OUT INTO THE AREA.
PRECIPITABLE WATERS INCREASING WILL SUPPORT BETTER MOISTURE FOR
DEEP CONVECTION WITH THE TEMPERATURES WARMING UP INTO THE 70S.
EXPECT SHOWERS AND THUNDERSTORMS TO MOVE OFF OF THE HIGHER
TERRAIN...ESPECIALLY AS A WEAK LOBE OF ENERGY MOVES THROUGH THE
AREA FRIDAY NIGHT. DID RAISE POPS OVER SOUTHEAST MONTANA TO
INDICATE BETTER CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS.
BORSUM

.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...

KEPT THE EXISTING LONG TERM FORECAST IN TACT AND JUST MADE SOME
SMALL ADJUSTMENTS HERE AND THERE TO POPS. THE MAIN FOCUS WAS TO
BUMP POPS UP OVER THE EAST FOR SATURDAY NIGHT THROUGH THE DAY
SUNDAY. MODELS WERE CONSISTENTLY BRINGING THE NORTHERN PART OF A
STRETCHED OUT UPPER LOW INTO NORTHEAST WYOMING SATURDAY NIGHT AND
SLOWLY TRACKING INTO NORTHEAST INTO NORTH DAKOTA ON SUNDAY.
PERSISTENT EAST TO SOUTHEAST SURFACE WINDS WILL ALLOW PRECIPITABLE
WATER AMOUNTS OF AROUND AN INCH TO MOVE INTO SOUTHEAST MONTANA.
ATMOSHPERE NOT EXPECTED TO BE TERRIBLY UNSTABLE...BUT WITH DEEP
MOISTURE AND WEAK STEERING WINDS...COULD HAVE SHOWERS WITH HEAVY
RAIN.

THE NEXT SYSTEM TO IMPACT THE AREA WILL BE ON TUESDAY. AN UPPER
LOW OVER WESTERN BRITISH COLUMBIA DROPS SOUTHEAST INTO WASHINGTON
ON MONDAY. ENERGY OUT AHEAD OF THIS LOW WILL KICK ACROSS WESTERN
AND CENTRAL ZONES ON TUESDAY. BOTH ECMWF AND THE GFS WERE SHOWING
THIS. THIS WILL LIKELY BE THE BEST CHANCE OF GETTING SHOWERS INTO
THE BILLINGS AREA. SHOWERS OVER THE WEEKEND WILL LIKELY BE TIED TO
THE TERRAIN AND WEAK STEERING WINDS WILL CAUSE TROUBLE FOR THE
SHOWERS IN THEIR ATTEMPT TO MOVE OFF THE FOOTHILLS. TEMPERATURES
WILL BE SEASONAL WITH LOW LEVEL EAST WINDS. TWH
&&

.AVIATION...

CLOUDS WILL INCREASE OVER THE SOUTHWEST MOUNTAINS TODAY WITH A
WEAK SYSTEM IN SOUTHERN IDAHO SLOWLY APPROACHING WESTERN MONTANA.
A FEW SHOWERS WILL DEVELOP OVER THE BEARTOOTH/ABSAROKA MOUNTAINS
BY EARLY AFTERNOON. CONDITIONS WILL REAMIN VFR...BUT LOCAL MVFR
CONDITIONS ARE POSSIBLE IN HEAVIER SHOWERS FROM KLVM SOUTHWARD.
MOUNTAINS WILL BE PARTIALLY OBSCURED...ESPECIALLY THIS AFTERNOON
IN SHOWERS. TWH/AAG

&&

.PRELIMINARY POINT TEMP/POPS...

    TDY FRI     SAT     SUN     MON     TUE     WED
-------------------------------------------------------
BIL 067 044/071 046/064 045/062 045/070 048/069 048/070
    0/B 02/T    43/T    33/T    32/T    23/T    33/T
LVM 064 040/067 043/062 042/062 039/067 043/065 042/069
    2/T 24/T    44/T    43/T    33/T    34/T    44/T
HDN 070 044/073 045/066 045/063 045/071 048/071 047/073
    0/U 02/T    33/T    33/T    32/T    23/T    33/T
MLS 070 045/072 046/065 047/063 047/069 048/071 049/072
    0/U 02/T    23/T    44/T    43/T    22/T    23/T
4BQ 067 043/068 044/061 047/059 044/067 046/069 047/069
    0/U 02/T    24/T    56/T    43/T    23/T    33/T
BHK 068 041/068 042/060 045/060 044/065 044/069 045/067
    0/U 01/N    24/T    56/T    55/T    32/T    33/T
SHR 064 041/065 041/060 043/058 040/067 043/066 043/068
    0/B 13/T    34/T    44/T    32/T    24/T    43/T

&&

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

&&

$$
WEATHER.GOV/BILLINGS




000
FXUS65 KTFX 211054
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
450 AM MDT THU MAY 21 2015

.DISCUSSION...
THURSDAY THROUGH SATURDAY...
SHOWERS AND THUNDERSTORMS WILL BECOME MORE PREVALENT OVER THE NEXT
FEW DAYS AS MOISTURE FROM A LOW PRESSURE SYSTEM MOVING ACROSS THE
SOUTHERN US IS EJECTED UP INTO FROM THE SOUTH. THE SYSTEM LOOKS TO
STAY FAR ENOUGH TO THE SOUTH TO ELIMINATE THE CHANCE OF A
WIDESPREAD WETTING RAIN...INSTEAD AFTERNOON SHOWERS AND
THUNDERSTORMS LOOK TO DEVELOP EACH AFTERNOON AND SHOULD INCREASE
IN COVERAGE OF THE AREA THROUGH THE FIRST HALF OF THE WEEKEND.
RELATIVELY WEAK SHEAR WILL LIMIT THE CHANCES FOR ANY OF THE
SHOWERS OR THUNDERSTORMS TO DEVELOP INTO SEVERE STORMS...BUT
STRONG STORMS ARE POSSIBLE AND COULD PRODUCE SMALL HAIL AND GUSTY
WINDS ALONG WITH BRIEF HEAVY RAINFALL. MODELS SUGGEST THAT THERE
IS ENOUGH WIND ALOFT TO ALLOW FOR STORMS TO MOVE OFF OF ANY
INITIATION POINT AND THIS SHOULD LIMIT THE POTENTIAL FOR LONG
DURATION HEAVY RAINS FROM NEARLY STATIONARY STORMS. TEMPERATURES
ARE EXPECTED TO BE NEAR OR SLIGHTLY ABOVE SEASONAL AVERAGES
THROUGH FRIDAY WITH ONLY A SLIGHT COOLDOWN TO SEASONAL AVERAGES ON
SATURDAY. WINDS SHOULD BE LIGHT AND EASTERY AGAIN TODAY...WITH
SOME LOCATIONS BECOMING GUSTY IN THE AFTERNOON...ESPECIALLY NEAR
ANY SHOWER OR THUNDERSTORM. SUK

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.AVIATION... UPDATED 1050Z. VFR CONDITIONS ARE ONCE AGAIN EXPECTED.
CLEAR SKIES TO A FEW CLOUDS AROUND 12000 FT CAN BE EXPECTED NEAR AND
NORTH OF A LINE FROM KLWT THROUGH KGTF. SOUTH OF THAT LINE EXPECT
ISOLATED SHOWERS THIS MORNING WITH SCATTERED SHOWERS BUT NUMEROUS
SHOWERS OVER THE MOUNTAINS THIS AFTERNOON. ALSO EXPECT SCATTERED
THUNDERSTORMS THIS AFTERNOON. GUSTY WINDS TO NEAR 40 KTS CAN BE
EXPECTED WITH A FEW OF THE THUNDERSTORMS. SHOWERS AND THUNDERSTORMS
WILL MOSTLY DISSIPATE NEAR AND AFTER MIDNIGHT. CONFIDENCE IN
FORECAST WINDS IS ABOVE AVERAGE. BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  42  70  47 /  20  10  20  30
CTB  68  38  69  41 /   0   0  10  10
HLN  70  45  71  49 /  40  30  30  30
BZN  66  40  69  43 /  50  20  40  30
WEY  59  32  62  35 /  60  40  60  40
DLN  64  41  67  44 /  70  50  40  40
HVR  71  38  74  43 /   0   0  10  30
LWT  66  42  68  45 /   0  10  40  50

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS




000
FXUS65 KTFX 211054
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
450 AM MDT THU MAY 21 2015

.DISCUSSION...
THURSDAY THROUGH SATURDAY...
SHOWERS AND THUNDERSTORMS WILL BECOME MORE PREVALENT OVER THE NEXT
FEW DAYS AS MOISTURE FROM A LOW PRESSURE SYSTEM MOVING ACROSS THE
SOUTHERN US IS EJECTED UP INTO FROM THE SOUTH. THE SYSTEM LOOKS TO
STAY FAR ENOUGH TO THE SOUTH TO ELIMINATE THE CHANCE OF A
WIDESPREAD WETTING RAIN...INSTEAD AFTERNOON SHOWERS AND
THUNDERSTORMS LOOK TO DEVELOP EACH AFTERNOON AND SHOULD INCREASE
IN COVERAGE OF THE AREA THROUGH THE FIRST HALF OF THE WEEKEND.
RELATIVELY WEAK SHEAR WILL LIMIT THE CHANCES FOR ANY OF THE
SHOWERS OR THUNDERSTORMS TO DEVELOP INTO SEVERE STORMS...BUT
STRONG STORMS ARE POSSIBLE AND COULD PRODUCE SMALL HAIL AND GUSTY
WINDS ALONG WITH BRIEF HEAVY RAINFALL. MODELS SUGGEST THAT THERE
IS ENOUGH WIND ALOFT TO ALLOW FOR STORMS TO MOVE OFF OF ANY
INITIATION POINT AND THIS SHOULD LIMIT THE POTENTIAL FOR LONG
DURATION HEAVY RAINS FROM NEARLY STATIONARY STORMS. TEMPERATURES
ARE EXPECTED TO BE NEAR OR SLIGHTLY ABOVE SEASONAL AVERAGES
THROUGH FRIDAY WITH ONLY A SLIGHT COOLDOWN TO SEASONAL AVERAGES ON
SATURDAY. WINDS SHOULD BE LIGHT AND EASTERY AGAIN TODAY...WITH
SOME LOCATIONS BECOMING GUSTY IN THE AFTERNOON...ESPECIALLY NEAR
ANY SHOWER OR THUNDERSTORM. SUK

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.AVIATION... UPDATED 1050Z. VFR CONDITIONS ARE ONCE AGAIN EXPECTED.
CLEAR SKIES TO A FEW CLOUDS AROUND 12000 FT CAN BE EXPECTED NEAR AND
NORTH OF A LINE FROM KLWT THROUGH KGTF. SOUTH OF THAT LINE EXPECT
ISOLATED SHOWERS THIS MORNING WITH SCATTERED SHOWERS BUT NUMEROUS
SHOWERS OVER THE MOUNTAINS THIS AFTERNOON. ALSO EXPECT SCATTERED
THUNDERSTORMS THIS AFTERNOON. GUSTY WINDS TO NEAR 40 KTS CAN BE
EXPECTED WITH A FEW OF THE THUNDERSTORMS. SHOWERS AND THUNDERSTORMS
WILL MOSTLY DISSIPATE NEAR AND AFTER MIDNIGHT. CONFIDENCE IN
FORECAST WINDS IS ABOVE AVERAGE. BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  42  70  47 /  20  10  20  30
CTB  68  38  69  41 /   0   0  10  10
HLN  70  45  71  49 /  40  30  30  30
BZN  66  40  69  43 /  50  20  40  30
WEY  59  32  62  35 /  60  40  60  40
DLN  64  41  67  44 /  70  50  40  40
HVR  71  38  74  43 /   0   0  10  30
LWT  66  42  68  45 /   0  10  40  50

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 211054
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
450 AM MDT THU MAY 21 2015

.DISCUSSION...
THURSDAY THROUGH SATURDAY...
SHOWERS AND THUNDERSTORMS WILL BECOME MORE PREVALENT OVER THE NEXT
FEW DAYS AS MOISTURE FROM A LOW PRESSURE SYSTEM MOVING ACROSS THE
SOUTHERN US IS EJECTED UP INTO FROM THE SOUTH. THE SYSTEM LOOKS TO
STAY FAR ENOUGH TO THE SOUTH TO ELIMINATE THE CHANCE OF A
WIDESPREAD WETTING RAIN...INSTEAD AFTERNOON SHOWERS AND
THUNDERSTORMS LOOK TO DEVELOP EACH AFTERNOON AND SHOULD INCREASE
IN COVERAGE OF THE AREA THROUGH THE FIRST HALF OF THE WEEKEND.
RELATIVELY WEAK SHEAR WILL LIMIT THE CHANCES FOR ANY OF THE
SHOWERS OR THUNDERSTORMS TO DEVELOP INTO SEVERE STORMS...BUT
STRONG STORMS ARE POSSIBLE AND COULD PRODUCE SMALL HAIL AND GUSTY
WINDS ALONG WITH BRIEF HEAVY RAINFALL. MODELS SUGGEST THAT THERE
IS ENOUGH WIND ALOFT TO ALLOW FOR STORMS TO MOVE OFF OF ANY
INITIATION POINT AND THIS SHOULD LIMIT THE POTENTIAL FOR LONG
DURATION HEAVY RAINS FROM NEARLY STATIONARY STORMS. TEMPERATURES
ARE EXPECTED TO BE NEAR OR SLIGHTLY ABOVE SEASONAL AVERAGES
THROUGH FRIDAY WITH ONLY A SLIGHT COOLDOWN TO SEASONAL AVERAGES ON
SATURDAY. WINDS SHOULD BE LIGHT AND EASTERY AGAIN TODAY...WITH
SOME LOCATIONS BECOMING GUSTY IN THE AFTERNOON...ESPECIALLY NEAR
ANY SHOWER OR THUNDERSTORM. SUK

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.AVIATION... UPDATED 1050Z. VFR CONDITIONS ARE ONCE AGAIN EXPECTED.
CLEAR SKIES TO A FEW CLOUDS AROUND 12000 FT CAN BE EXPECTED NEAR AND
NORTH OF A LINE FROM KLWT THROUGH KGTF. SOUTH OF THAT LINE EXPECT
ISOLATED SHOWERS THIS MORNING WITH SCATTERED SHOWERS BUT NUMEROUS
SHOWERS OVER THE MOUNTAINS THIS AFTERNOON. ALSO EXPECT SCATTERED
THUNDERSTORMS THIS AFTERNOON. GUSTY WINDS TO NEAR 40 KTS CAN BE
EXPECTED WITH A FEW OF THE THUNDERSTORMS. SHOWERS AND THUNDERSTORMS
WILL MOSTLY DISSIPATE NEAR AND AFTER MIDNIGHT. CONFIDENCE IN
FORECAST WINDS IS ABOVE AVERAGE. BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  42  70  47 /  20  10  20  30
CTB  68  38  69  41 /   0   0  10  10
HLN  70  45  71  49 /  40  30  30  30
BZN  66  40  69  43 /  50  20  40  30
WEY  59  32  62  35 /  60  40  60  40
DLN  64  41  67  44 /  70  50  40  40
HVR  71  38  74  43 /   0   0  10  30
LWT  66  42  68  45 /   0  10  40  50

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 211054
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
450 AM MDT THU MAY 21 2015

.DISCUSSION...
THURSDAY THROUGH SATURDAY...
SHOWERS AND THUNDERSTORMS WILL BECOME MORE PREVALENT OVER THE NEXT
FEW DAYS AS MOISTURE FROM A LOW PRESSURE SYSTEM MOVING ACROSS THE
SOUTHERN US IS EJECTED UP INTO FROM THE SOUTH. THE SYSTEM LOOKS TO
STAY FAR ENOUGH TO THE SOUTH TO ELIMINATE THE CHANCE OF A
WIDESPREAD WETTING RAIN...INSTEAD AFTERNOON SHOWERS AND
THUNDERSTORMS LOOK TO DEVELOP EACH AFTERNOON AND SHOULD INCREASE
IN COVERAGE OF THE AREA THROUGH THE FIRST HALF OF THE WEEKEND.
RELATIVELY WEAK SHEAR WILL LIMIT THE CHANCES FOR ANY OF THE
SHOWERS OR THUNDERSTORMS TO DEVELOP INTO SEVERE STORMS...BUT
STRONG STORMS ARE POSSIBLE AND COULD PRODUCE SMALL HAIL AND GUSTY
WINDS ALONG WITH BRIEF HEAVY RAINFALL. MODELS SUGGEST THAT THERE
IS ENOUGH WIND ALOFT TO ALLOW FOR STORMS TO MOVE OFF OF ANY
INITIATION POINT AND THIS SHOULD LIMIT THE POTENTIAL FOR LONG
DURATION HEAVY RAINS FROM NEARLY STATIONARY STORMS. TEMPERATURES
ARE EXPECTED TO BE NEAR OR SLIGHTLY ABOVE SEASONAL AVERAGES
THROUGH FRIDAY WITH ONLY A SLIGHT COOLDOWN TO SEASONAL AVERAGES ON
SATURDAY. WINDS SHOULD BE LIGHT AND EASTERY AGAIN TODAY...WITH
SOME LOCATIONS BECOMING GUSTY IN THE AFTERNOON...ESPECIALLY NEAR
ANY SHOWER OR THUNDERSTORM. SUK

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.AVIATION... UPDATED 1050Z. VFR CONDITIONS ARE ONCE AGAIN EXPECTED.
CLEAR SKIES TO A FEW CLOUDS AROUND 12000 FT CAN BE EXPECTED NEAR AND
NORTH OF A LINE FROM KLWT THROUGH KGTF. SOUTH OF THAT LINE EXPECT
ISOLATED SHOWERS THIS MORNING WITH SCATTERED SHOWERS BUT NUMEROUS
SHOWERS OVER THE MOUNTAINS THIS AFTERNOON. ALSO EXPECT SCATTERED
THUNDERSTORMS THIS AFTERNOON. GUSTY WINDS TO NEAR 40 KTS CAN BE
EXPECTED WITH A FEW OF THE THUNDERSTORMS. SHOWERS AND THUNDERSTORMS
WILL MOSTLY DISSIPATE NEAR AND AFTER MIDNIGHT. CONFIDENCE IN
FORECAST WINDS IS ABOVE AVERAGE. BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  42  70  47 /  20  10  20  30
CTB  68  38  69  41 /   0   0  10  10
HLN  70  45  71  49 /  40  30  30  30
BZN  66  40  69  43 /  50  20  40  30
WEY  59  32  62  35 /  60  40  60  40
DLN  64  41  67  44 /  70  50  40  40
HVR  71  38  74  43 /   0   0  10  30
LWT  66  42  68  45 /   0  10  40  50

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 211054
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
450 AM MDT THU MAY 21 2015

.DISCUSSION...
THURSDAY THROUGH SATURDAY...
SHOWERS AND THUNDERSTORMS WILL BECOME MORE PREVALENT OVER THE NEXT
FEW DAYS AS MOISTURE FROM A LOW PRESSURE SYSTEM MOVING ACROSS THE
SOUTHERN US IS EJECTED UP INTO FROM THE SOUTH. THE SYSTEM LOOKS TO
STAY FAR ENOUGH TO THE SOUTH TO ELIMINATE THE CHANCE OF A
WIDESPREAD WETTING RAIN...INSTEAD AFTERNOON SHOWERS AND
THUNDERSTORMS LOOK TO DEVELOP EACH AFTERNOON AND SHOULD INCREASE
IN COVERAGE OF THE AREA THROUGH THE FIRST HALF OF THE WEEKEND.
RELATIVELY WEAK SHEAR WILL LIMIT THE CHANCES FOR ANY OF THE
SHOWERS OR THUNDERSTORMS TO DEVELOP INTO SEVERE STORMS...BUT
STRONG STORMS ARE POSSIBLE AND COULD PRODUCE SMALL HAIL AND GUSTY
WINDS ALONG WITH BRIEF HEAVY RAINFALL. MODELS SUGGEST THAT THERE
IS ENOUGH WIND ALOFT TO ALLOW FOR STORMS TO MOVE OFF OF ANY
INITIATION POINT AND THIS SHOULD LIMIT THE POTENTIAL FOR LONG
DURATION HEAVY RAINS FROM NEARLY STATIONARY STORMS. TEMPERATURES
ARE EXPECTED TO BE NEAR OR SLIGHTLY ABOVE SEASONAL AVERAGES
THROUGH FRIDAY WITH ONLY A SLIGHT COOLDOWN TO SEASONAL AVERAGES ON
SATURDAY. WINDS SHOULD BE LIGHT AND EASTERY AGAIN TODAY...WITH
SOME LOCATIONS BECOMING GUSTY IN THE AFTERNOON...ESPECIALLY NEAR
ANY SHOWER OR THUNDERSTORM. SUK

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.AVIATION... UPDATED 1050Z. VFR CONDITIONS ARE ONCE AGAIN EXPECTED.
CLEAR SKIES TO A FEW CLOUDS AROUND 12000 FT CAN BE EXPECTED NEAR AND
NORTH OF A LINE FROM KLWT THROUGH KGTF. SOUTH OF THAT LINE EXPECT
ISOLATED SHOWERS THIS MORNING WITH SCATTERED SHOWERS BUT NUMEROUS
SHOWERS OVER THE MOUNTAINS THIS AFTERNOON. ALSO EXPECT SCATTERED
THUNDERSTORMS THIS AFTERNOON. GUSTY WINDS TO NEAR 40 KTS CAN BE
EXPECTED WITH A FEW OF THE THUNDERSTORMS. SHOWERS AND THUNDERSTORMS
WILL MOSTLY DISSIPATE NEAR AND AFTER MIDNIGHT. CONFIDENCE IN
FORECAST WINDS IS ABOVE AVERAGE. BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  42  70  47 /  20  10  20  30
CTB  68  38  69  41 /   0   0  10  10
HLN  70  45  71  49 /  40  30  30  30
BZN  66  40  69  43 /  50  20  40  30
WEY  59  32  62  35 /  60  40  60  40
DLN  64  41  67  44 /  70  50  40  40
HVR  71  38  74  43 /   0   0  10  30
LWT  66  42  68  45 /   0  10  40  50

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KTFX 211054
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
450 AM MDT THU MAY 21 2015

.DISCUSSION...
THURSDAY THROUGH SATURDAY...
SHOWERS AND THUNDERSTORMS WILL BECOME MORE PREVALENT OVER THE NEXT
FEW DAYS AS MOISTURE FROM A LOW PRESSURE SYSTEM MOVING ACROSS THE
SOUTHERN US IS EJECTED UP INTO FROM THE SOUTH. THE SYSTEM LOOKS TO
STAY FAR ENOUGH TO THE SOUTH TO ELIMINATE THE CHANCE OF A
WIDESPREAD WETTING RAIN...INSTEAD AFTERNOON SHOWERS AND
THUNDERSTORMS LOOK TO DEVELOP EACH AFTERNOON AND SHOULD INCREASE
IN COVERAGE OF THE AREA THROUGH THE FIRST HALF OF THE WEEKEND.
RELATIVELY WEAK SHEAR WILL LIMIT THE CHANCES FOR ANY OF THE
SHOWERS OR THUNDERSTORMS TO DEVELOP INTO SEVERE STORMS...BUT
STRONG STORMS ARE POSSIBLE AND COULD PRODUCE SMALL HAIL AND GUSTY
WINDS ALONG WITH BRIEF HEAVY RAINFALL. MODELS SUGGEST THAT THERE
IS ENOUGH WIND ALOFT TO ALLOW FOR STORMS TO MOVE OFF OF ANY
INITIATION POINT AND THIS SHOULD LIMIT THE POTENTIAL FOR LONG
DURATION HEAVY RAINS FROM NEARLY STATIONARY STORMS. TEMPERATURES
ARE EXPECTED TO BE NEAR OR SLIGHTLY ABOVE SEASONAL AVERAGES
THROUGH FRIDAY WITH ONLY A SLIGHT COOLDOWN TO SEASONAL AVERAGES ON
SATURDAY. WINDS SHOULD BE LIGHT AND EASTERY AGAIN TODAY...WITH
SOME LOCATIONS BECOMING GUSTY IN THE AFTERNOON...ESPECIALLY NEAR
ANY SHOWER OR THUNDERSTORM. SUK

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.AVIATION... UPDATED 1050Z. VFR CONDITIONS ARE ONCE AGAIN EXPECTED.
CLEAR SKIES TO A FEW CLOUDS AROUND 12000 FT CAN BE EXPECTED NEAR AND
NORTH OF A LINE FROM KLWT THROUGH KGTF. SOUTH OF THAT LINE EXPECT
ISOLATED SHOWERS THIS MORNING WITH SCATTERED SHOWERS BUT NUMEROUS
SHOWERS OVER THE MOUNTAINS THIS AFTERNOON. ALSO EXPECT SCATTERED
THUNDERSTORMS THIS AFTERNOON. GUSTY WINDS TO NEAR 40 KTS CAN BE
EXPECTED WITH A FEW OF THE THUNDERSTORMS. SHOWERS AND THUNDERSTORMS
WILL MOSTLY DISSIPATE NEAR AND AFTER MIDNIGHT. CONFIDENCE IN
FORECAST WINDS IS ABOVE AVERAGE. BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  42  70  47 /  20  10  20  30
CTB  68  38  69  41 /   0   0  10  10
HLN  70  45  71  49 /  40  30  30  30
BZN  66  40  69  43 /  50  20  40  30
WEY  59  32  62  35 /  60  40  60  40
DLN  64  41  67  44 /  70  50  40  40
HVR  71  38  74  43 /   0   0  10  30
LWT  66  42  68  45 /   0  10  40  50

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KMSO 210934
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
334 AM MDT THU MAY 21 2015

.DISCUSSION...A developing surface low pressure system will sit
over eastern Washington for the next couple days. This system will
spread a moist unstable air mass over central Idaho and western
Montana that will help kick off scattered showers and
thunderstorms over the region today and tomorrow afternoons and
evenings. Locations that will be impacted the most, will be areas
south of I-90 in western Montana, and north-central Idaho. The
biggest impact from the thunderstorms will be heavy rain, which
could pose issues to burn scars and steep terrain, with rock and
mudslides. If traveling along highways 12, 14, 93, and 95 in Idaho
the next couple days keep a close eye on in coming weather.
Dangerous lightning and gusty winds will also accompany these
storms, so if planning outdoor activities, have a plan in place
for when inclement weather arrives.

Model agreement is very poor early next week for the details, but
the overall pattern remains unchanged. The broad pattern remains
unsettled with mild but changeable conditions daily. Expect near
normal or above normal temperatures and periods of light rain.
Northwest Montana, however, will likely remain drier than usual
for this time of year with no significant systems on the horizon
to make up for the recent precipitation deficit.

&&

.AVIATION...A developing surface low pressure system over eastern
Washington will spread a moist and unsettled air mass over the
region for the next couple days. Scattered showers and
thunderstorms are expected to develop over western Montana and
central Idaho this afternoon and evening, as well as on Friday.
KMSO, KBTM, and KSMN stands the best chance to being impacted from
these storms. Heavy rain, with occasional lightning and gusty
winds will be the main threat. Thunderstorms are expected to
develop around KBTM and KSMN between 21/2000-2100Z this afternoon,
and around 21/2300Z for KMSO.


&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

$$



000
FXUS65 KMSO 210934
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
334 AM MDT THU MAY 21 2015

.DISCUSSION...A developing surface low pressure system will sit
over eastern Washington for the next couple days. This system will
spread a moist unstable air mass over central Idaho and western
Montana that will help kick off scattered showers and
thunderstorms over the region today and tomorrow afternoons and
evenings. Locations that will be impacted the most, will be areas
south of I-90 in western Montana, and north-central Idaho. The
biggest impact from the thunderstorms will be heavy rain, which
could pose issues to burn scars and steep terrain, with rock and
mudslides. If traveling along highways 12, 14, 93, and 95 in Idaho
the next couple days keep a close eye on in coming weather.
Dangerous lightning and gusty winds will also accompany these
storms, so if planning outdoor activities, have a plan in place
for when inclement weather arrives.

Model agreement is very poor early next week for the details, but
the overall pattern remains unchanged. The broad pattern remains
unsettled with mild but changeable conditions daily. Expect near
normal or above normal temperatures and periods of light rain.
Northwest Montana, however, will likely remain drier than usual
for this time of year with no significant systems on the horizon
to make up for the recent precipitation deficit.

&&

.AVIATION...A developing surface low pressure system over eastern
Washington will spread a moist and unsettled air mass over the
region for the next couple days. Scattered showers and
thunderstorms are expected to develop over western Montana and
central Idaho this afternoon and evening, as well as on Friday.
KMSO, KBTM, and KSMN stands the best chance to being impacted from
these storms. Heavy rain, with occasional lightning and gusty
winds will be the main threat. Thunderstorms are expected to
develop around KBTM and KSMN between 21/2000-2100Z this afternoon,
and around 21/2300Z for KMSO.


&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

$$




000
FXUS65 KTFX 210928
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
328 AM MDT THU MAY 21 2015

.DISCUSSION...
THURSDAY THROUGH SATURDAY...
SHOWERS AND THUNDERSTORMS WILL BECOME MORE PREVALENT OVER THE NEXT
FEW DAYS AS MOISTURE FROM A LOW PRESSURE SYSTEM MOVING ACROSS THE
SOUTHERN US IS EJECTED UP INTO FROM THE SOUTH. THE SYSTEM LOOKS TO
STAY FAR ENOUGH TO THE SOUTH TO ELIMINATE THE CHANCE OF A
WIDESPREAD WETTING RAIN...INSTEAD AFTERNOON SHOWERS AND
THUNDERSTORMS LOOK TO DEVELOP EACH AFTERNOON AND SHOULD INCREASE
IN COVERAGE OF THE AREA THROUGH THE FIRST HALF OF THE WEEKEND.
RELATIVELY WEAK SHEAR WILL LIMIT THE CHANCES FOR ANY OF THE
SHOWERS OR THUNDERSTORMS TO DEVELOP INTO SEVERE STORMS...BUT
STRONG STORMS ARE POSSIBLE AND COULD PRODUCE SMALL HAIL AND GUSTY
WINDS ALONG WITH BRIEF HEAVY RAINFALL. MODELS SUGGEST THAT THERE
IS ENOUGH WIND ALOFT TO ALLOW FOR STORMS TO MOVE OFF OF ANY
INITIATION POINT AND THIS SHOULD LIMIT THE POTENTIAL FOR LONG
DURATION HEAVY RAINS FROM NEARLY STATIONARY STORMS. TEMPERATURES
ARE EXPECTED TO BE NEAR OR SLIGHTLY ABOVE SEASONAL AVERAGES
THROUGH FRIDAY WITH ONLY A SLIGHT COOLDOWN TO SEASONAL AVERAGES ON
SATURDAY. WINDS SHOULD BE LIGHT AND EASTERY AGAIN TODAY...WITH
SOME LOCATIONS BECOMING GUSTY IN THE AFTERNOON...ESPECIALLY NEAR
ANY SHOWER OR THUNDERSTORM. SUK

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.AVIATION...
UPDATED 0420Z. VFR CONDITIONS EXPECTED WITH MOSTLY CLEAR SKIES
THROUGH THURS MORNING AT ALL TAF SITES EXCEPT KBZN WHICH SEE BKN MID-
LEVEL CLOUDS (GENERALLY ABOVE 10000 FT). ALSO EARLIER BREEZY WINDS
(GUSTS OF 20-25 KTS) HAVE DISSIPATED AND WILL REMAIN LIGHT DURING
THE OVERNIGHT PERIOD, BUT PICK UP AGAIN THURS AFTN VCNTY KHVR/KLWT.
SPOTTY -SHRA ALSO POSSIBLE NEAR KHLN/KBZN LATE TOMORROW AFTN.
WARANAUSKAS

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  42  70  47 /  20  10  20  30
CTB  68  38  69  41 /   0   0  10  10
HLN  70  45  71  49 /  40  30  30  30
BZN  66  40  69  43 /  50  20  40  30
WEY  59  32  62  35 /  60  40  60  40
DLN  64  41  67  44 /  70  50  40  40
HVR  71  38  74  43 /   0   0  10  30
LWT  66  42  68  45 /   0  10  40  50

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS




000
FXUS65 KTFX 210928
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
328 AM MDT THU MAY 21 2015

.DISCUSSION...
THURSDAY THROUGH SATURDAY...
SHOWERS AND THUNDERSTORMS WILL BECOME MORE PREVALENT OVER THE NEXT
FEW DAYS AS MOISTURE FROM A LOW PRESSURE SYSTEM MOVING ACROSS THE
SOUTHERN US IS EJECTED UP INTO FROM THE SOUTH. THE SYSTEM LOOKS TO
STAY FAR ENOUGH TO THE SOUTH TO ELIMINATE THE CHANCE OF A
WIDESPREAD WETTING RAIN...INSTEAD AFTERNOON SHOWERS AND
THUNDERSTORMS LOOK TO DEVELOP EACH AFTERNOON AND SHOULD INCREASE
IN COVERAGE OF THE AREA THROUGH THE FIRST HALF OF THE WEEKEND.
RELATIVELY WEAK SHEAR WILL LIMIT THE CHANCES FOR ANY OF THE
SHOWERS OR THUNDERSTORMS TO DEVELOP INTO SEVERE STORMS...BUT
STRONG STORMS ARE POSSIBLE AND COULD PRODUCE SMALL HAIL AND GUSTY
WINDS ALONG WITH BRIEF HEAVY RAINFALL. MODELS SUGGEST THAT THERE
IS ENOUGH WIND ALOFT TO ALLOW FOR STORMS TO MOVE OFF OF ANY
INITIATION POINT AND THIS SHOULD LIMIT THE POTENTIAL FOR LONG
DURATION HEAVY RAINS FROM NEARLY STATIONARY STORMS. TEMPERATURES
ARE EXPECTED TO BE NEAR OR SLIGHTLY ABOVE SEASONAL AVERAGES
THROUGH FRIDAY WITH ONLY A SLIGHT COOLDOWN TO SEASONAL AVERAGES ON
SATURDAY. WINDS SHOULD BE LIGHT AND EASTERY AGAIN TODAY...WITH
SOME LOCATIONS BECOMING GUSTY IN THE AFTERNOON...ESPECIALLY NEAR
ANY SHOWER OR THUNDERSTORM. SUK

FRIDAY NIGHT THROUGH TUESDAY...DO NOT SEE ANY WEATHER SYSTEMS THAT
WOULD HAVE A WIDESPREAD NEGATIVE IMPACT ON TRAVEL OR OUTDOOR
ACTIVITIES OVER THE LONG HOLIDAY WEEKEND. THERE WILL BE SEVERAL
UPPER LOWS TO CONTEND WITH DURING THE PERIOD BUT ALMOST ALL OF THEM
WILL NOT BE OVER THE FORECAST AREA. MODELS ARE IN BETTER AGREEMENT
TONIGHT WITH THEIR HANDLING THESE UPPER LOWS. ON SATURDAY ONE UPPER
LOW WILL BE OVER FAR SOUTHEAST MONTANA WITH ANOTHER OVER THE GREAT
BASIN AND A THIRD IN THE VICINITY OF THE PACIFIC NORTHWEST. NONE
WILL HAVE MUCH BEARING ON OUR FORECAST AREA. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL BE DUE PRIMARILY TO UPSLOPE FLOW.
ON SUNDAY AN UPPER LOW WILL BE OVER THE WESTERN DAKOTAS WITH ANOTHER
IN THE AREA FROM NORTHERN CALIFORNIA TO TO OREGON. THERE MIGHT BE A
LITTLE LESS SHOWER ACTIVITY THEN ON SATURDAY. ON MEMORIAL DAY AN
UPPER LOW IS FORECAST TO BE OVER THE GREAT BASIN WHICH COULD LEAD TO
SCATTERED SHOWERS OR THUNDERSTORMS OVER SOUTHWEST MONTANA. FARTHER
NORTH MODELS DIFFER WITH THE GFS HAVING AN UPPER TROUGH OVER CENTRAL
MONTANA AND SCATTERED SHOWERS IN THAT SAME AREA. THE ECMWF ON THE
OTHER HAND DOES NOT SHOW THIS FEATURE AND IS DRY. TUESDAY
DIFFERENCES CONTINUE WITH THE UPPER AIR PATTERN AS THE ECMWF HAS AN
UPPER LOW OVER SOUTHERN IDAHO WITH SHOWERS OR THUNDERSTORMS FOR
SOUTHWEST MONTANA. THE GFS ON THE OTHER HAND HAS AN UPPER RIDGE OVER
IDAHO AND WESTERN MONTANA BUT DUE TO PRIMARILY TERRAIN EFFECTS
HAS SCATTERED SHOWERS OR THUNDERSTORMS MAINLY OVER THE WESTERN
MOUNTAINS. SEASONABLE HIGH TEMPERATURES MOSTLY IN THE 60S CAN BE
EXPECTED OVER THE HOLIDAY WEEKEND. BLANK

&&

.AVIATION...
UPDATED 0420Z. VFR CONDITIONS EXPECTED WITH MOSTLY CLEAR SKIES
THROUGH THURS MORNING AT ALL TAF SITES EXCEPT KBZN WHICH SEE BKN MID-
LEVEL CLOUDS (GENERALLY ABOVE 10000 FT). ALSO EARLIER BREEZY WINDS
(GUSTS OF 20-25 KTS) HAVE DISSIPATED AND WILL REMAIN LIGHT DURING
THE OVERNIGHT PERIOD, BUT PICK UP AGAIN THURS AFTN VCNTY KHVR/KLWT.
SPOTTY -SHRA ALSO POSSIBLE NEAR KHLN/KBZN LATE TOMORROW AFTN.
WARANAUSKAS

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  42  70  47 /  20  10  20  30
CTB  68  38  69  41 /   0   0  10  10
HLN  70  45  71  49 /  40  30  30  30
BZN  66  40  69  43 /  50  20  40  30
WEY  59  32  62  35 /  60  40  60  40
DLN  64  41  67  44 /  70  50  40  40
HVR  71  38  74  43 /   0   0  10  30
LWT  66  42  68  45 /   0  10  40  50

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS



000
FXUS65 KBYZ 210919
AFDBYZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
319 AM MDT THU MAY 21 2015

.SHORT TERM...VALID FOR TDY AND FRI...

WEAK FLOW ALOFT WITH DRIER AIR HAVING BEEN PUSHED INTO THE EASTERN
HALF OF THE AREA BY A CUTOFF RIDGE OVER SOUTHERN CANADA. LOW ALONG
THE CALIFORNIA COAST IS GOING TO DIG A BIT MORE THAN PREVIOUSLY
EXPECTED TODAY AND THIS MEANS THE REGION WILL SEE ONLY AN
INCREMENTAL CHANGE IN THE WEATHER. MOST OF THE REGION WILL BE DRY
BUT ENOUGH MOISTURE WILL BE PUSHED INTO THE SOUTHWEST MOUNTAINS
FOR LOW CHANCE OF SHOWERS. DID LOWER POPS FOR THE FOOTHILLS LATE
TODAY AND OVERNIGHT AS GFS AND ECMWF INDICATE THE MOISTURE WILL
UNLIKELY TRAVEL OFF OF THE HIGHER TERRAIN. OVER THE PLAINS LOW
LEVEL FLOW REMAINS EASTERLY BUT DOES TREND A BIT TOWARDS
SOUTHEASTERLY WHICH WILL WEAKEN THE UPSLOPE COMPONENT A BIT AND
SUPPORT WARMER TEMPERATURES.

FRIDAY THE UPPER LOW MOVES ACROSS CALIFORNIA TOWARDS THE SOUTHERN
GREAT BASIN AND STRONGER MID LEVEL WINDS TRANSLATING DOWNSTREAM
CAUSE FALLING SURFACE PRESSURES ALONG THE COLORADO FRONT RANGE.
WHILE FLOW ALOFT OVER MONTANA AND NORTHERN WYOMING REMAIN WEAK
MOISTURE IS MOVING NORTHWARD ESPECIALLY AS THE CANADIAN RIDGE
LOSES THE ABILITY TO PUSH DRIER AIR OUT INTO THE AREA.
PRECIPITABLE WATERS INCREASING WILL SUPPORT BETTER MOISTURE FOR
DEEP CONVECTION WITH THE TEMPERATURES WARMING UP INTO THE 70S.
EXPECT SHOWERS AND THUNDERSTORMS TO MOVE OFF OF THE HIGHER
TERRAIN...ESPECIALLY AS A WEAK LOBE OF ENERGY MOVES THROUGH THE
AREA FRIDAY NIGHT. DID RAISE POPS OVER SOUTHEAST MONTANA TO
INDICATE BETTER CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS.
BORSUM
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...

KEPT THE EXISTING LONG TERM FORECAST IN TACT AND JUST MADE SOME
SMALL ADJUSTMENTS HERE AND THERE TO POPS. THE MAIN FOCUS WAS TO
BUMP POPS UP OVER THE EAST FOR SATURDAY NIGHT THROUGH THE DAY
SUNDAY. MODELS WERE CONSISTENTLY BRINGING THE NORTHERN PART OF A
STRETCHED OUT UPPER LOW INTO NORTHEAST WYOMING SATURDAY NIGHT AND
SLOWLY TRACKING INTO NORTHEAST INTO NORTH DAKOTA ON SUNDAY.
PERSISTENT EAST TO SOUTHEAST SURFACE WINDS WILL ALLOW PRECIPITABLE
WATER AMOUNTS OF AROUND AN INCH TO MOVE INTO SOUTHEAST MONTANA.
ATMOSHPERE NOT EXPECTED TO BE TERRIBLY UNSTABLE...BUT WITH DEEP
MOISTURE AND WEAK STEERING WINDS...COULD HAVE SHOWERS WITH HEAVY
RAIN.

THE NEXT SYSTEM TO IMPACT THE AREA WILL BE ON TUESDAY. AN UPPER
LOW OVER WESTERN BRITISH COLUMBIA DROPS SOUTHEAST INTO WASHINGTON
ON MONDAY. ENERGY OUT AHEAD OF THIS LOW WILL KICK ACROSS WESTERN
AND CENTRAL ZONES ON TUESDAY. BOTH ECMWF AND THE GFS WERE SHOWING
THIS. THIS WILL LIKELY BE THE BEST CHANCE OF GETTING SHOWERS INTO
THE BILLINGS AREA. SHOWERS OVER THE WEEKEND WILL LIKELY BE TIED TO
THE TERRAIN AND WEAK STEERING WINDS WILL CAUSE TROUBLE FOR THE
SHOWERS IN THEIR ATTEMPT TO MOVE OFF THE FOOTHILLS. TEMPERATURES
WILL BE SEASONAL WITH LOW LEVEL EAST WINDS. TWH
&&

.AVIATION...

CLOUDS WILL INCREASE OVER THE SOUTHWEST MOUNTAINS TODAY WITH A
WEAK SYSTEM IN SOUTHERN IDAHO SLOWLY APPROACHING WESTERN MONTANA.
A FEW SHOWERS WILL DEVELOP OVER THE BEARTOOTH/ABSAROKA MOUNTAINS
BY EARLY AFTERNOON. CONDITIONS WILL REAMIN VFR...BUT LOCAL MVFR
CONDITIONS ARE POSSIBLE IN HEAVIER SHOWERS FROM KLVM SOUTHWARD.
MOUNTAINS WILL BE PARTIALLY OBSCURED...ESPECIALLY THIS AFTERNOON
IN SHOWERS. TWH
&&

.PRELIMINARY POINT TEMP/POPS...

    TDY FRI     SAT     SUN     MON     TUE     WED
-------------------------------------------------------
BIL 067 044/071 046/064 045/062 045/070 048/069 048/070
    1/B 12/T    43/T    33/T    32/T    23/T    33/T
LVM 064 040/067 043/062 042/062 039/067 043/065 042/069
    2/W 24/T    44/T    43/T    33/T    34/T    44/T
HDN 070 044/073 045/066 045/063 045/071 048/071 047/073
    1/U 12/T    33/T    33/T    32/T    23/T    33/T
MLS 070 045/072 046/065 047/063 047/069 048/071 049/072
    0/U 02/T    23/T    44/T    43/T    22/T    23/T
4BQ 067 043/068 044/061 047/059 044/067 046/069 047/069
    0/U 02/T    24/T    56/T    43/T    23/T    33/T
BHK 068 041/068 042/060 045/060 044/065 044/069 045/067
    0/U 01/N    24/T    56/T    55/T    32/T    33/T
SHR 064 041/065 041/060 043/058 040/067 043/066 043/068
    1/B 13/T    34/T    44/T    32/T    24/T    43/T

&&

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

&&

$$
WEATHER.GOV/BILLINGS



000
FXUS65 KBYZ 210919
AFDBYZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
319 AM MDT THU MAY 21 2015

.SHORT TERM...VALID FOR TDY AND FRI...

WEAK FLOW ALOFT WITH DRIER AIR HAVING BEEN PUSHED INTO THE EASTERN
HALF OF THE AREA BY A CUTOFF RIDGE OVER SOUTHERN CANADA. LOW ALONG
THE CALIFORNIA COAST IS GOING TO DIG A BIT MORE THAN PREVIOUSLY
EXPECTED TODAY AND THIS MEANS THE REGION WILL SEE ONLY AN
INCREMENTAL CHANGE IN THE WEATHER. MOST OF THE REGION WILL BE DRY
BUT ENOUGH MOISTURE WILL BE PUSHED INTO THE SOUTHWEST MOUNTAINS
FOR LOW CHANCE OF SHOWERS. DID LOWER POPS FOR THE FOOTHILLS LATE
TODAY AND OVERNIGHT AS GFS AND ECMWF INDICATE THE MOISTURE WILL
UNLIKELY TRAVEL OFF OF THE HIGHER TERRAIN. OVER THE PLAINS LOW
LEVEL FLOW REMAINS EASTERLY BUT DOES TREND A BIT TOWARDS
SOUTHEASTERLY WHICH WILL WEAKEN THE UPSLOPE COMPONENT A BIT AND
SUPPORT WARMER TEMPERATURES.

FRIDAY THE UPPER LOW MOVES ACROSS CALIFORNIA TOWARDS THE SOUTHERN
GREAT BASIN AND STRONGER MID LEVEL WINDS TRANSLATING DOWNSTREAM
CAUSE FALLING SURFACE PRESSURES ALONG THE COLORADO FRONT RANGE.
WHILE FLOW ALOFT OVER MONTANA AND NORTHERN WYOMING REMAIN WEAK
MOISTURE IS MOVING NORTHWARD ESPECIALLY AS THE CANADIAN RIDGE
LOSES THE ABILITY TO PUSH DRIER AIR OUT INTO THE AREA.
PRECIPITABLE WATERS INCREASING WILL SUPPORT BETTER MOISTURE FOR
DEEP CONVECTION WITH THE TEMPERATURES WARMING UP INTO THE 70S.
EXPECT SHOWERS AND THUNDERSTORMS TO MOVE OFF OF THE HIGHER
TERRAIN...ESPECIALLY AS A WEAK LOBE OF ENERGY MOVES THROUGH THE
AREA FRIDAY NIGHT. DID RAISE POPS OVER SOUTHEAST MONTANA TO
INDICATE BETTER CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS.
BORSUM
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...

KEPT THE EXISTING LONG TERM FORECAST IN TACT AND JUST MADE SOME
SMALL ADJUSTMENTS HERE AND THERE TO POPS. THE MAIN FOCUS WAS TO
BUMP POPS UP OVER THE EAST FOR SATURDAY NIGHT THROUGH THE DAY
SUNDAY. MODELS WERE CONSISTENTLY BRINGING THE NORTHERN PART OF A
STRETCHED OUT UPPER LOW INTO NORTHEAST WYOMING SATURDAY NIGHT AND
SLOWLY TRACKING INTO NORTHEAST INTO NORTH DAKOTA ON SUNDAY.
PERSISTENT EAST TO SOUTHEAST SURFACE WINDS WILL ALLOW PRECIPITABLE
WATER AMOUNTS OF AROUND AN INCH TO MOVE INTO SOUTHEAST MONTANA.
ATMOSHPERE NOT EXPECTED TO BE TERRIBLY UNSTABLE...BUT WITH DEEP
MOISTURE AND WEAK STEERING WINDS...COULD HAVE SHOWERS WITH HEAVY
RAIN.

THE NEXT SYSTEM TO IMPACT THE AREA WILL BE ON TUESDAY. AN UPPER
LOW OVER WESTERN BRITISH COLUMBIA DROPS SOUTHEAST INTO WASHINGTON
ON MONDAY. ENERGY OUT AHEAD OF THIS LOW WILL KICK ACROSS WESTERN
AND CENTRAL ZONES ON TUESDAY. BOTH ECMWF AND THE GFS WERE SHOWING
THIS. THIS WILL LIKELY BE THE BEST CHANCE OF GETTING SHOWERS INTO
THE BILLINGS AREA. SHOWERS OVER THE WEEKEND WILL LIKELY BE TIED TO
THE TERRAIN AND WEAK STEERING WINDS WILL CAUSE TROUBLE FOR THE
SHOWERS IN THEIR ATTEMPT TO MOVE OFF THE FOOTHILLS. TEMPERATURES
WILL BE SEASONAL WITH LOW LEVEL EAST WINDS. TWH
&&

.AVIATION...

CLOUDS WILL INCREASE OVER THE SOUTHWEST MOUNTAINS TODAY WITH A
WEAK SYSTEM IN SOUTHERN IDAHO SLOWLY APPROACHING WESTERN MONTANA.
A FEW SHOWERS WILL DEVELOP OVER THE BEARTOOTH/ABSAROKA MOUNTAINS
BY EARLY AFTERNOON. CONDITIONS WILL REAMIN VFR...BUT LOCAL MVFR
CONDITIONS ARE POSSIBLE IN HEAVIER SHOWERS FROM KLVM SOUTHWARD.
MOUNTAINS WILL BE PARTIALLY OBSCURED...ESPECIALLY THIS AFTERNOON
IN SHOWERS. TWH
&&

.PRELIMINARY POINT TEMP/POPS...

    TDY FRI     SAT     SUN     MON     TUE     WED
-------------------------------------------------------
BIL 067 044/071 046/064 045/062 045/070 048/069 048/070
    1/B 12/T    43/T    33/T    32/T    23/T    33/T
LVM 064 040/067 043/062 042/062 039/067 043/065 042/069
    2/W 24/T    44/T    43/T    33/T    34/T    44/T
HDN 070 044/073 045/066 045/063 045/071 048/071 047/073
    1/U 12/T    33/T    33/T    32/T    23/T    33/T
MLS 070 045/072 046/065 047/063 047/069 048/071 049/072
    0/U 02/T    23/T    44/T    43/T    22/T    23/T
4BQ 067 043/068 044/061 047/059 044/067 046/069 047/069
    0/U 02/T    24/T    56/T    43/T    23/T    33/T
BHK 068 041/068 042/060 045/060 044/065 044/069 045/067
    0/U 01/N    24/T    56/T    55/T    32/T    33/T
SHR 064 041/065 041/060 043/058 040/067 043/066 043/068
    1/B 13/T    34/T    44/T    32/T    24/T    43/T

&&

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

&&

$$
WEATHER.GOV/BILLINGS




000
FXUS65 KGGW 210855
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
255 AM MDT THU MAY 21 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SATURDAY...

NORTHEAST MONTANA REMAINS UNDER A NARROW UPPER RIDGE THAT HAS
BROUGHT CLEAR SKIES AND RELATIVELY LIGHT WINDS FOR THE LAST COUPLE
OF DAYS. THIS RIDGE WILL PERSIST TODAY MAINTAINING MOSTLY CLEAR
SKIES. BUT THE SURFACE HIGH SHIFTS EAST. THIS WILL DEVELOP BRISK
SOUTHEAST WINDS THIS AFTERNOON AND EARLY EVENING. CURRENT MODELS
SUGGEST THAT WINDS WILL GENERALLY RUN JUST BELOW ADVISORY
CRITERIA. SO WILL LET THE NEXT SHIFT DECIDE ON THE UPDATE IF AN A
WIND ADVISORY IS NEEDED.

TONIGHT/FRIDAY...A CLOSED LOW OFF THE SOUTHERN CALIFORNIA COAST
WILL BEGIN TO LIFT INTO THE GREAT BASIN REGION TO SEND MOISTURE
FURTHER NORTH INTO OUR AREA. THIS WILL INCREASE SKY COVER FROM THE
SOUTH. BY AFTERNOON INSTABILITY INCREASES OVER OUR WEST WITH WEAK
TO MODERATE CAPE AND NEGATIVE LI. THIS COULD LEAD TO ISOLATED
THUNDERSTORMS. SOUTHEAST WINDS LOOK TO BE STRONGER...ENOUGH FOR A
LIKELY ADVISORY FOR FORT PECK LAKE.

FRIDAY NIGHT AND SATURDAY...THE CLOSED UPPER LOW MOVES ACROSS THE
CENTRAL ROCKIES AND SHOWS SIGNS OF STACKING UP WITH A CLOSED
SURFACE LOW. THIS SHOULD KEEP MOST OF THE ENERGY TO OUR SOUTH.
HOWEVER CONTINUED UNSTABLE CONDITIONS COULD RESULT IN MORE
ISOLATED THUNDER. EXPECT BRISK EAST WINDS TO DEVELOP AGAIN.

FLOW ALOFT WILL NOT BE STRONG FROM ANY DIRECTION DURING THE
PERIOD. SO DO NOT EXPECT ANY WARM AIR SURGING IN. THEREFORE
TEMPERATURES WILL RUN CLOSE TO OR SLIGHTLY ABOVE NORMAL.

SCT

.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
SATURDAY NIGHT AND SUNDAY FEATURES A BROAD UPPER TROUGH OVER THE
WEST AND AN UPPER RIDGE TO EAST OF NORTHEAST MONTANA. THE TROUGH
WILL LIFT NORTH INTO MONTANA AND NORTH DAKOTA BY MONDAY. THEN...THE
FLOW PATTERN ALOFT OVER MONTANA WILL BE WEAK...VARIABLE AND UN-
FOCUSED MONDAY AND TUESDAY. THE SOUTHEAST HALF OF THE FORECAST
AREA HAS A BETTER CHANCE OF SEEING SHOWERS MAYBE THUNDERSTORMS AT
TIMES BETWEEN SATURDAY NIGHT AND MONDAY WHERE THE DEEPER MOISTURE
IS EXPECTED.

MODEL DIFFERENCES SHOW UP TUESDAY AND BEYOND AS GFS HAS A NW FLOW
ALOFT WITH A BACK DOOR COLD FRONT ON WEDNESDAY. ECMWF HAS AN UPPER
TROUGH OVER THE PACIFIC NW ON TUESDAY THAT EVENTUALLY MOVES EAST
ACROSS MONTANA WEDNESDAY AND THURSDAY. WILL MAINTAIN A
CHANCE/SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR NOW.  FORRESTER


&&

.AVIATION...
VFR.

MAINLY CLEAR SKIES TODAY AND TONIGHT. LIGHT MAINLY EAST WINDS THIS
MORNING WILL BECOME SOUTHEAST 10 TO 20 KNOTS THIS AFTERNOON. EAST
WINDS WILL CONTINUE AROUND 10 KNOTS TONIGHT.


&&

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

&&

$$

WEATHER.GOV/GLASGOW





000
FXUS65 KGGW 210855
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
255 AM MDT THU MAY 21 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SATURDAY...

NORTHEAST MONTANA REMAINS UNDER A NARROW UPPER RIDGE THAT HAS
BROUGHT CLEAR SKIES AND RELATIVELY LIGHT WINDS FOR THE LAST COUPLE
OF DAYS. THIS RIDGE WILL PERSIST TODAY MAINTAINING MOSTLY CLEAR
SKIES. BUT THE SURFACE HIGH SHIFTS EAST. THIS WILL DEVELOP BRISK
SOUTHEAST WINDS THIS AFTERNOON AND EARLY EVENING. CURRENT MODELS
SUGGEST THAT WINDS WILL GENERALLY RUN JUST BELOW ADVISORY
CRITERIA. SO WILL LET THE NEXT SHIFT DECIDE ON THE UPDATE IF AN A
WIND ADVISORY IS NEEDED.

TONIGHT/FRIDAY...A CLOSED LOW OFF THE SOUTHERN CALIFORNIA COAST
WILL BEGIN TO LIFT INTO THE GREAT BASIN REGION TO SEND MOISTURE
FURTHER NORTH INTO OUR AREA. THIS WILL INCREASE SKY COVER FROM THE
SOUTH. BY AFTERNOON INSTABILITY INCREASES OVER OUR WEST WITH WEAK
TO MODERATE CAPE AND NEGATIVE LI. THIS COULD LEAD TO ISOLATED
THUNDERSTORMS. SOUTHEAST WINDS LOOK TO BE STRONGER...ENOUGH FOR A
LIKELY ADVISORY FOR FORT PECK LAKE.

FRIDAY NIGHT AND SATURDAY...THE CLOSED UPPER LOW MOVES ACROSS THE
CENTRAL ROCKIES AND SHOWS SIGNS OF STACKING UP WITH A CLOSED
SURFACE LOW. THIS SHOULD KEEP MOST OF THE ENERGY TO OUR SOUTH.
HOWEVER CONTINUED UNSTABLE CONDITIONS COULD RESULT IN MORE
ISOLATED THUNDER. EXPECT BRISK EAST WINDS TO DEVELOP AGAIN.

FLOW ALOFT WILL NOT BE STRONG FROM ANY DIRECTION DURING THE
PERIOD. SO DO NOT EXPECT ANY WARM AIR SURGING IN. THEREFORE
TEMPERATURES WILL RUN CLOSE TO OR SLIGHTLY ABOVE NORMAL.

SCT

.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
SATURDAY NIGHT AND SUNDAY FEATURES A BROAD UPPER TROUGH OVER THE
WEST AND AN UPPER RIDGE TO EAST OF NORTHEAST MONTANA. THE TROUGH
WILL LIFT NORTH INTO MONTANA AND NORTH DAKOTA BY MONDAY. THEN...THE
FLOW PATTERN ALOFT OVER MONTANA WILL BE WEAK...VARIABLE AND UN-
FOCUSED MONDAY AND TUESDAY. THE SOUTHEAST HALF OF THE FORECAST
AREA HAS A BETTER CHANCE OF SEEING SHOWERS MAYBE THUNDERSTORMS AT
TIMES BETWEEN SATURDAY NIGHT AND MONDAY WHERE THE DEEPER MOISTURE
IS EXPECTED.

MODEL DIFFERENCES SHOW UP TUESDAY AND BEYOND AS GFS HAS A NW FLOW
ALOFT WITH A BACK DOOR COLD FRONT ON WEDNESDAY. ECMWF HAS AN UPPER
TROUGH OVER THE PACIFIC NW ON TUESDAY THAT EVENTUALLY MOVES EAST
ACROSS MONTANA WEDNESDAY AND THURSDAY. WILL MAINTAIN A
CHANCE/SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR NOW.  FORRESTER


&&

.AVIATION...
VFR.

MAINLY CLEAR SKIES TODAY AND TONIGHT. LIGHT MAINLY EAST WINDS THIS
MORNING WILL BECOME SOUTHEAST 10 TO 20 KNOTS THIS AFTERNOON. EAST
WINDS WILL CONTINUE AROUND 10 KNOTS TONIGHT.


&&

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

&&

$$

WEATHER.GOV/GLASGOW





000
FXUS65 KGGW 210855
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
255 AM MDT THU MAY 21 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SATURDAY...

NORTHEAST MONTANA REMAINS UNDER A NARROW UPPER RIDGE THAT HAS
BROUGHT CLEAR SKIES AND RELATIVELY LIGHT WINDS FOR THE LAST COUPLE
OF DAYS. THIS RIDGE WILL PERSIST TODAY MAINTAINING MOSTLY CLEAR
SKIES. BUT THE SURFACE HIGH SHIFTS EAST. THIS WILL DEVELOP BRISK
SOUTHEAST WINDS THIS AFTERNOON AND EARLY EVENING. CURRENT MODELS
SUGGEST THAT WINDS WILL GENERALLY RUN JUST BELOW ADVISORY
CRITERIA. SO WILL LET THE NEXT SHIFT DECIDE ON THE UPDATE IF AN A
WIND ADVISORY IS NEEDED.

TONIGHT/FRIDAY...A CLOSED LOW OFF THE SOUTHERN CALIFORNIA COAST
WILL BEGIN TO LIFT INTO THE GREAT BASIN REGION TO SEND MOISTURE
FURTHER NORTH INTO OUR AREA. THIS WILL INCREASE SKY COVER FROM THE
SOUTH. BY AFTERNOON INSTABILITY INCREASES OVER OUR WEST WITH WEAK
TO MODERATE CAPE AND NEGATIVE LI. THIS COULD LEAD TO ISOLATED
THUNDERSTORMS. SOUTHEAST WINDS LOOK TO BE STRONGER...ENOUGH FOR A
LIKELY ADVISORY FOR FORT PECK LAKE.

FRIDAY NIGHT AND SATURDAY...THE CLOSED UPPER LOW MOVES ACROSS THE
CENTRAL ROCKIES AND SHOWS SIGNS OF STACKING UP WITH A CLOSED
SURFACE LOW. THIS SHOULD KEEP MOST OF THE ENERGY TO OUR SOUTH.
HOWEVER CONTINUED UNSTABLE CONDITIONS COULD RESULT IN MORE
ISOLATED THUNDER. EXPECT BRISK EAST WINDS TO DEVELOP AGAIN.

FLOW ALOFT WILL NOT BE STRONG FROM ANY DIRECTION DURING THE
PERIOD. SO DO NOT EXPECT ANY WARM AIR SURGING IN. THEREFORE
TEMPERATURES WILL RUN CLOSE TO OR SLIGHTLY ABOVE NORMAL.

SCT

.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
SATURDAY NIGHT AND SUNDAY FEATURES A BROAD UPPER TROUGH OVER THE
WEST AND AN UPPER RIDGE TO EAST OF NORTHEAST MONTANA. THE TROUGH
WILL LIFT NORTH INTO MONTANA AND NORTH DAKOTA BY MONDAY. THEN...THE
FLOW PATTERN ALOFT OVER MONTANA WILL BE WEAK...VARIABLE AND UN-
FOCUSED MONDAY AND TUESDAY. THE SOUTHEAST HALF OF THE FORECAST
AREA HAS A BETTER CHANCE OF SEEING SHOWERS MAYBE THUNDERSTORMS AT
TIMES BETWEEN SATURDAY NIGHT AND MONDAY WHERE THE DEEPER MOISTURE
IS EXPECTED.

MODEL DIFFERENCES SHOW UP TUESDAY AND BEYOND AS GFS HAS A NW FLOW
ALOFT WITH A BACK DOOR COLD FRONT ON WEDNESDAY. ECMWF HAS AN UPPER
TROUGH OVER THE PACIFIC NW ON TUESDAY THAT EVENTUALLY MOVES EAST
ACROSS MONTANA WEDNESDAY AND THURSDAY. WILL MAINTAIN A
CHANCE/SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR NOW.  FORRESTER


&&

.AVIATION...
VFR.

MAINLY CLEAR SKIES TODAY AND TONIGHT. LIGHT MAINLY EAST WINDS THIS
MORNING WILL BECOME SOUTHEAST 10 TO 20 KNOTS THIS AFTERNOON. EAST
WINDS WILL CONTINUE AROUND 10 KNOTS TONIGHT.


&&

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

&&

$$

WEATHER.GOV/GLASGOW






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