147
FXUS65 KTFX 130907
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
307 AM MDT SAT JUN 13 2026
KEY MESSAGES
- COOLER TEMPERATURES AND WIDELY SCATTERED SHOWERS LINGER
TODAY, WITH COOL AND FROSTY CONDITIONS FOR SOME AREAS SUNDAY
MORNING.
- A WARMING TREND BEGINS ON SUNDAY AND CONTINUES THROUGH EARLY
NEXT WEEK, WITH WINDY CONDITIONS DEVELOPING AHEAD OF A COLD
FRONT ON TUESDAY.
- THERE WILL BE A PERIOD OF SHOWERS AND THUNDERSTORMS AND
MORE GUSTY WINDS WITH THE FRONTAL PASSAGE LATE TUESDAY INTO
WEDNESDAY.
- GENERAL UNSETTLED CONDITIONS CONTINUE FOR THE FOR THE SECOND
HALF OF NEXT WEEK WITH MORE OPPORTUNITIES FOR SHOWERS AND
STORMS.
DISCUSSION
- METEOROLOGICAL OVERVIEW:
NORTHWESTERLY FLOW ALOFT WILL REMAIN IN PLACE THROUGH AT LEAST
THE LATTER PART OF THE WORKWEEK. LINGERING SHOWERS FROM LAST NIGHT
CONTINUE TO THIN OUT AS THEY MOVE SOUTHWARD INTO SOUTHWEST MT.
ANOTHER SHORTWAVE WILL BRING ANOTHER ROUND OF SHOWERS AND PERHAPS
A STORM OR TWO THIS AFTERNOON AND EVENING, ALTHOUGH THIS ACTIVITY
LOOKS TO BE MORE SCATTERED IN NATURE AND MOSTLY DEVELOPING OVER
AND NEAR AREAS OF HIGHER TERRAIN, ESPECIALLY THE CENTRAL ISLAND
RANGES.
AFTER A COOL, FROSTY SUNDAY MORNING, THE EASTERN PERIPHERY OF A
PACIFIC NW RIDGE WILL WILL MOVE INTO THE NORTHERN ROCKIES AND
INITIATE AN EARLY WEEK WARMING TREND. WESTERLY FLOW ALOFT
INCREASES LATE MONDAY INTO TUESDAY IN ADVANCE OF AN APPROACHING
SHORTWAVE AND ATTENDANT COLD FRONT WITH H850/H700 WINDS INCREASING
TO THE 40 TO 50 KT RANGE BY TUESDAY EVENING. THIS WILL BRING
WINDY AND DRY CONDITIONS TUESDAY AFTERNOON WHILE TEMPERATURES
SURGE WELL INTO THE 80S.
A CANADIAN COLD FRONT WILL MOVE SOUTHWARD SOMETIME LATE TUESDAY
INTO WEDNESDAY AND BRING A ROUND OF SHOWERS AND THUNDERSTORMS.
TEMPERATURES FALL BELOW AVERAGE BEHIND THE FRONT WEDNESDAY AND
THURSDAY WHILE GUSTY NORTHWESTERLY WINDS CONTINUE THROUGH
WEDNESDAY AFTERNOON, STRONGEST FOR CENTRAL/NORTH-CENTRAL LOCATIONS
EAST OF I15. PASSING SHORTWAVES BRING MORE ROUNDS OF SHOWERS AND
THUNDERSTORMS HEADING INTO THE FIRST HALF OF NEXT WEEKEND. - RCG
- FORECAST CONFIDENCE & SCENARIOS:
CHILLY/FROSTY OVERNIGHT AND MORNING TEMPERATURES...
PARTIAL CLEARING AND LIGHT WINDS WILL RESULT IN CHILLY LOW
TEMPERATURES FOR THE NEXT COUPLE OF NIGHTS, ESPECIALLY TONIGHT
INTO SUNDAY MORNING. MOST LOWER ELEVATIONS WILL SEE MORNING LOWS
IN THE 30S, ALONG WITH SOME INSTANCES OF PATCHY FROST. THE WIND
PROTECTED SOUTHWEST VALLEYS WILL SEE THE COLDEST CONDITIONS AND
MOST WIDESPREAD FROST.
WINDY CONDITIONS TUESDAY INTO WEDNESDAY...
WESTERLY WINDS INCREASE ON TUESDAY IN ADVANCE OF AN APPROACHING
THROUGH AND COLD FRONT. THE NAEFS ANOMALY INDEX CONTINUES TO
ADVERTISE H700/H500 WINDS INCREASING UP TO TWO TO THREE STANDARD
DEVIATIONS ABOVE CLIMATOLOGY AND NBM PROBABILITIES FOR 50 MPH +
GUSTS ARE NOW RUNNING IN THE 60 TO 80% RANGE FOR PORTIONS OF THE
FORECAST AREA, INCLUDING THE ROCKY MOUNTAIN FRONT/PLAINS WEST OF
I15 AND AREAS OVER AND NEAR THE HIGHER TERRAIN OF
CENTRAL/SOUTHWEST MT. THE BIGGEST UNCERTAINTY CONTINUES TO BE WHEN
THE STRONGEST WINDS ALOFT MOVE THROUGH AND WHETHER IT WILL BE
DURING PEAK DIURNAL MIXING OR LATER IN THE EVENING WITH LESS
MOMENTUM TRANSFER. ANOTHER FACTOR THAT MAY SLOW WIND SPEEDS AND
REDUCE THE DURATION OF PEAK WINDS WILL BE AN EARLY ARRIVAL OF THE
CANADIAN COLD FRONT. THE TIMING OF THIS FRONT WILL AFFECT NORTHERN
AREAS THE MOST, PARTICULARLY AREAS ALONG THE NORTHERN ROCKY
MOUNTAIN FRONT.
THE WINDS WILL SHIFT TO A MORE NORTHWESTERLY DIRECTION ON
WEDNESDAY AND WILL GENERALLY BE STRONGEST OVER THE PLAINS EAST OF
I15, NAMELY SOUTHEASTERN BLAINE AND FERGUS COUNTIES. WITH THIS
EVENT STILL DAYS AWAY, THERE'S TIME TO IRON OUT THESE DETAILS. THE
PRIMARY IMPACT LOOKS BE INCLEMENT OUTDOOR RECREATION AND
DIFFICULT TRAVEL FOR THOSE OPERATING HIGH PROFILE VEHICLES. THE
COMBINATION OF TEMPERATURES WARMING WELL INTO THE 80S AND RHS
FALLING TO NEAR CRITICALLY LOW LEVELS ON TUESDAY WILL ALSO BE
MONITORED FOR FIRE WEATHER CONCERNS, ALTHOUGH FUELS WILL BE LESS
RECEPTIVE GIVEN THE RECENT RAINFALL AND GREENUP. - RCG
AVIATION
13/06Z TAF PERIOD
WHILE RAIN HAS GENERALLY ENDED ACROSS NORTH CENTRAL AND
SOUTHWESTERN MONTANA, A FEW LINGERING AREAS OF LIGHT RAIN
(CURRENTLY PRIMARILY ALONG A LINE FROM WEST OF KGTF TO NEAR KLWT)
WILL CONTINUE TO GRADUALLY SLIDE SOUTHWARD THROUGH THE OVERNIGHT.
AS THEY DO, THEY SHOULD CONTINUE TO DIMINISH, BUT WILL BRING
BRIEF PERIODS OF VISIBILITY TO AROUND 3-6SM OR SO. CEILINGS WILL
BE THE BIGGER CHALLENGE, AS MVFR CEILINGS ARE LIKELY TO BE PRESENT
ACROSS MUCH OF THE AREA OVERNIGHT, AND SOME LOCALIZED FOG CAN'T
ENTIRELY BE RULED OUT (THOUGH NOT ENOUGH CONFIDENCE TO PUT IN TAFS
AT THIS TIME). LUDWIG
PRELIMINARY POINT TEMPS/POPS
GTF 62 40 70 44 / 20 0 0 0
CTB 61 37 71 44 / 10 0 0 0
HLN 63 40 73 44 / 30 0 0 0
BZN 62 35 70 39 / 40 10 0 0
WYS 63 30 69 32 / 10 10 0 0
DLN 64 36 70 40 / 20 0 0 0
HVR 67 40 73 45 / 10 0 0 0
LWT 57 37 67 40 / 30 10 0 0
TFX WATCHES/WARNINGS/ADVISORIES
NONE.
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