635
FXUS65 KTFX 280605
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1205 AM MDT TUE JUL 28 2026
KEY MESSAGES
- REMAINING HOT THROUGH THE REST OF THE WORK WEEK, WITH THE
HOTTEST DAY OF THE UPCOMING WEEK OCCURRING ON SATURDAY.
- WINDS INCREASE LATE SATURDAY AND LAST INTO SUNDAY, WITH THE
STRONGEST WINDS OCCURRING ALONG THE ROCKY MOUNTAIN FRONT.
- BRIEF REPRIEVE FROM THE HEAT EARLY NEXT WEEK.
DISCUSSION
- METEOROLOGICAL OVERVIEW:
UPPER LEVEL RIDGING WILL DOMINATE THROUGH MUCH OF THE FORECAST
PERIOD, WITH THE RIDGE BRINGING CONTINUED HOT TEMPERATURES TO MOST
LOCATIONS FROM SOUTHWEST THROUGH NORTH CENTRAL MONTANA UNTIL
SATURDAY. BY SUNDAY A POTENT LONGWAVE TROUGH WILL BREAKDOWN THE
RIDGE AND BRING INCREASING WINDS AND SLIGHTLY COOLER TEMPERATURES TO
THE NORTHERN ROCKIES, WITH TEMPERATURES FALLING BELOW NORMAL INTO
THE DAY ON MONDAY IN WAKE OF A COLD FRONT. MONSOONAL MOISTURE
LIFTING UP AND AROUND THE RIDGE WILL PROVIDE DAILY CHANCES FOR
ISOLATED SHOWERS AND STORMS; HOWEVER, MOST LOCATIONS WILL REMAIN DRY
OVER THE NEXT WEEK. - MOLDAN
- FORECAST CONFIDENCE & SCENARIOS:
RETURN OF EXTREME TEMPERATURES BY SATURDAY...
WHILE TEMPERATURES WILL REMAIN HOT THROUGH THE REMAINDER OF THE WORK
WEEK CLIMATE ANOMALY INDICATORS HAVE HONED IN ON SATURDAY BEING THE
HOTTEST DAY OF THE UPCOMING WEEK, WITH VALUES BECOMING UNUSUAL TO
VERY UNUSUAL WITH RESPECT TO LATE JULY/EARLY AUGUST CLIMATOLOGY. THE
FACT THAT THESE CLIMATE ANOMALY INDICATORS ARE SUGGESTING ANOTHER
PERIOD OF HOT TEMPERATURES IS REMARKABLE CONSIDERING THAT AUGUST 1ST
IS (AT MOST LOCATIONS) ONLY ONE DAY PAST THE CLIMATOLOGICAL PEAK FOR
AVERAGE HIGH TEMPERATURES ACROSS SOUTHWEST THROUGH NORTH CENTRAL
MONTANA. THE TABLE BELOW REPRESENTS THE POTENTIAL HIGH TEMPERATURE
SCENARIOS FOR SELECT CITIES ACROSS SOUTHWEST THROUGH NORTH CENTRAL
MONTANA, WITH THE "LOW END" SCENARIO BEING THE NBM10PCT (10% CHANCE
THAT TEMPERATURES ARE LOWER THAN THE LISTED VALUE), "MOST LIKELY"
SCENARIO BEING THE NBM50PCT, AND THE "HIGH END" SCENARIO BEING THE
NBM90PCT (10% CHANCE THAT TEMPERATURES EXCEED THE LISTED VALUE).
SATURDAY'S HIGH TEMPERATURE SCENARIOS
LOCATION LOW END | MOST LIKELY | HIGH END
BROWNING 88 | 93 | 98
CUT BANK 95 | 100 | 104
HAVRE 103 | 108 | 111
GREAT FALLS 102 | 105 | 107
LEWISTOWN 98 | 101 | 104
HELENA 97 | 100 | 104
WHITE SULPHUR SPRINGS 95 | 102 | 101
BOZEMAN 98 | 98 | 105
DILLON 95 | 98 | 100
ENNIS 94 | 98 | 100
WEST YELLOWSTONE 89 | 93 | 96
GIVEN THE PRESENCE OF REGIONAL WILDFIRES ACROSS THE NORTHERN ROCKIES
THE "HIGH END" SCENARIO WILL BE TOUGH TO REACH DUE TO DECREASED
SOLAR INSOLATION FROM THE SMOKE, WITH DENSE SMOKE HAVING THE ABILITY
TO HOLD TEMPERATURES BACK SOME 5 TO 10 DEGREES.
STRONG WINDS FROM SATURDAY NIGHT THROUGH SUNDAY...
CONFIDENCE IS INCREASING THAT A PERIOD OF STRONG, NEARING HIGH,
WINDS WILL IMPACT THE ROCKY MOUNTAIN FRONT FROM SATURDAY NIGHT
THROUGH THE DAY ON SUNDAY DUE TO THE COMBINATION OF MOUNTAIN WAVE
ACTIVITY (FROM THE LATE EVENING HOURS ON SATURDAY THROUGH SUNDAY
MORNING) AND DEEP MIXING (DURING THE DAYLIGHT HOURS ON SUNDAY). H700
WINDS PER NAEFS ANALYSIS ARE PROG'D TO REACH 40-50KTS FROM SATURDAY
EVENING THROUGH SUNDAY MORNING ACROSS THE AFOREMENTIONED AREA, WHICH
IS 2 TO NEARLY 3 STANDARD DEVIATIONS ABOVE NORMAL. THE TABLE BELOW
ARE THE NBM5.0 PROBABILITIES FOR WIND GUSTS TO EXCEED 45 MPH, 55
MPH, AND 65 MPH FOR SELECT LOCATIONS ALONG THE ROCKY MOUNTAIN FRONT
FOR THE PREVIOUSLY MENTIONED TIMEFRAME.
PROBABILITIES FOR WIND GUSTS TO EXCEED
LOCATION >45 MPH | >55 MPH | >65 MPH
MANY GLACIER VALLEY 55% | 15% | <5%
LOGAN PASS 50% | 10% | 0%
ST MARY 80% | 40% | 10%
TWO MEDICINE VALLEY 70% | 30% | 10%
EAST GLACIER 75% | 25% | 10%
BROWNING 70% | 25% | 5%
CUT BANK 75% | 20% | 5%
HEART BUTTE 80% | 30% | 20%
CHOTEAU 5% | 0% | 0%
AUGUSTA 20% | <5% | 0%
THOSE LOOKING TO TRAVEL OR RECREATE ALONG THE ROCKY MOUNTAIN FRONT
SHOULD BE PREPARED FOR STRONG WINDS; WHICH COULD MAKE DRIVING AND
HIKING DIFFICULT, LEAD TO FALLING TREES IN THE BACKCOUNTRY, AND/OR
LEAD TO THE SPREAD OF EXISTING/NEW WILDFIRES. - MOLDAN
AVIATION
28/06Z TAF PERIOD
WILDFIRE SMOKE FROM THE PACIFIC NORTHWEST WILL BE THE PRIMARY
CONCERN THROUGH THE TAF PERIOD. VISIBILITIES CAN DROP DOWN TO MVFR
AT TIMES IN THE MORNING DUE TO THE SMOKE ACROSS NORTH-CENTRAL MT.
ISOLATED SHOWERS AND THUNDERSTORMS CONTINUE INTO THE EARLY MORNING FOR
SOUTHWEST MT/CENTRAL MT. ANOTHER ROUND OF ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS FOR SOUTHWEST MT TUESDAY AFTERNOON AND
EARLY EVENING.
FOR KGTF: WINDS WILL PREVAIL OUT OF THE NORTH INTO THE EARLY
MORNING HOURS, BECOMING LIGHT AND VARIABLE THROUGH THE REST OF THE
MORNING. BY TUESDAY AFTERNOON, WINDS WILL PREVAIL MORE OUT OF THE
WEST. PROBABILITIES FOR A 15KT CROSSWIND REMAIN LOW THROUGH THE
MORNING (10%), BUT IT INCREASES TO 50% BY 28/22 THROUGH 29/02Z.
-WILSON
PRELIMINARY POINT TEMPS/POPS
GTF 95 61 94 60 / 0 0 0 0
CTB 91 56 89 55 / 0 0 0 0
HLN 94 59 93 59 / 10 0 10 10
BZN 94 58 92 57 / 20 0 20 10
WYS 88 49 85 47 / 10 0 30 20
DLN 91 55 88 54 / 10 0 20 10
HVR 98 60 95 59 / 0 0 0 0
LWT 93 58 90 57 / 20 20 10 20
TFX WATCHES/WARNINGS/ADVISORIES
NONE.
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