343
FXUS65 KTFX 310221
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
821 PM MDT FRI MAY 30 2025
KEY MESSAGES
KEY POINTS
- WARM AND DRY THROUGH THE WEEKEND THANKS TO HIGH
PRESSURE AT THE SURFACE AND ALOFT
- SHOWERS AND THUNDERSTORMS EXPECTED SUNDAY, SOME OF WHICH MAY
PRODUCE GUSTY WINDS
- COOLER START TO THE WORK WEEK, WITH TEMPERATURES SLOWLY
WARMING THROUGH THE WEEK
UPDATE
SATELLITE IMAGERY THIS EVENING SHOWS LITTLE OR NO CLOUDS ACROSS
THE AREA AS THE AXIS OF AN UPPER LEVEL RIDGE SHIFTS EAST ACROSS
THE NORTHERN ROCKIES. WEAK SURFACE TROUGHING TO THE LEE OF THE
CANADIAN ROCKIES WILL MAINTAIN 10-15 MPH SW WINDS ALONG THE
NORTHERN ROCKY MOUNTAIN FRONT AND ADJACENT PLAINS, KEEPING
TEMPERATURES RELATIVELY MILD ACROSS GLACIER COUNTY AND ADJACENT
AREAS OVERNIGHT AND SETTING THE STAGE FOR AN EXCEPTIONALLY EARLY
WARM DAY TOMORROW THERE. OTHERWISE, RELATIVELY LIGHT WINDS AND
MILD BUT SEASONABLE TEMPERATURES TONIGHT ELSEWHERE WITH A VERY
WARM DAY ON TRACK FOR TOMORROW ACROSS THE AREA. HOENISCH
DISCUSSION
/ISSUED 431 PM MDT FRI MAY 30 2025/
- METEOROLOGICAL OVERVIEW:
UPPER LEVEL RIDGING AND HIGH PRESSURE AT THE SURFACE WILL KEEP
THINGS WARM AND DRY TODAY AND SATURDAY WITH GENERALLY LIGHT WINDS
ACROSS THE AREA. AS SUCH, TEMPERATURES WILL BE THE MAIN IMPACT
TODAY AND TOMORROW, WITH WARM TEMPERATURES REACHING THE UPPER 70S
TODAY BEFORE SHOOTING UP INTO THE LOW 90S ON SATURDAY. WHILE THIS
IS EARLY FOR TEMPERATURES THIS WARM, THE SHORT NATURE OF THIS WARM
UP, EVEN COMBINED WITH WARM TEMPERATURES ON THURSDAY, DOES NOT
APPEAR TO RISE TO THE LEVEL OF NEEDING HEAT ADVISORIES AT THIS
TIME.
THE WARM AND QUIET STRETCH OF WEATHER COMES TO AN END ON
SUNDAY, AS A COLD FRONT PUSHES THROUGH THE AREA, BRINGING A ROUND
OF SHOWERS AND THUNDERSTORMS AHEAD OF FAIRLY LARGE COOLDOWN FOR
THE FIRST HALF OF NEXT WEEK. MOST OF THESE SHOWERS AND
THUNDERSTORMS WILL GENERALLY BE FOUND IN THE TERRAIN OF
SOUTHWESTERN MONTANA, WHERE A FEW GUSTY WINDS WILL BE POSSIBLE ON
SUNDAY THANKS TO STRONG INSTABILITY AND VERY DRY AIR NEAR THE
SURFACE.
BEHIND THIS COLD FRONT, COOLER, AND SOMEWHAT UNSETTLED,
WEATHER WILL LINGER ACROSS NORTH CENTRAL AND SOUTHWESTERN MONTANA,
WITH WIDESPREAD RAIN EXPECTED MONDAY AS TEMPERATURES STRUGGLE TO
GET OUT OF THE 50S ACROSS THE PLAINS (THOUGH THE SOUTHWESTERN
VALLEYS WILL SEE TEMPERATURES REACH INTO THE MID 60S. WHILE NOT AS
WIDESPREAD, EXPECT INCREASED CHANCES OF RAIN THROUGH NEXT WEEK AS
A SERIES OF WEAK WEATHER SYSTEMS MOVE THROUGH THE AREA THROUGH
MID TO LATE NEXT WEEK.
- FORECAST CONFIDENCE & SCENARIOS:
HOT TEMPERATURES ON SATURDAY :
TRANSIENT, BUT STRONG, UPPER LEVEL RIDGING WILL MOVE OVER THE
NORTHERN ROCKIES ON SATURDAY, WITH H500 HEIGHTS RUNNING NEARLY 3
STANDARD DEVIATIONS ABOVE NORMAL. CLIMATE ANOMALY INDICATORS SUCH AS
THE ECMWF EFIS SUPPORT AN UNUSUALLY HOT DAY BENEATH THIS RIDGE, WITH
EFI VALUES ACROSS SOUTHWEST THROUGH NORTH CENTRAL MONTANA LARGELY
RANGING FROM 0.8 TO 0.95. NBM PROBABILITIES FOR HIGH TEMPERATURES OF
90 DEGREES OR WARMER ARE THE HIGHEST ACROSS THE GOLDEN TRIANGLE
REGION OF THE CENTRAL AND NORTH CENTRAL MONTANA PLAINS AND IN THE
HELENA VALLEY WHERE VALUES OF 80% TO NEARLY 100% ARE COMMON.
THE TABLE BELOW SHOWS THE LATEST NBM PROBABILITIES FOR NEW RECORD
HIGH TEMPERATURES BEING SET ON SATURDAY, WITH THE CURRENT RECORD
HIGHS IMMEDIATE ADJACENT TO THE PROBABILITIES.
LOCATION FRIDAY
CUT BANK 99% BREAKING 86 DEGREES
HAVRE 4% BREAKING 94 DEGREES
GREAT FALLS 76% BREAKING 90 DEGREES
LEWISTOWN 12% BREAKING 87 DEGREES
HELENA 99% BREAKING 88 DEGREES
BOZEMAN 88% BREAKING 88 DEGREES
DILLON 44% BREAKING 87 DEGREES
RAIN FROM SUNDAY THROUGH TUESDAY :
AN UNSETTLED PATTERN IS STILL EXPECTED ACROSS THE NORTHERN ROCKIES
FROM THE SECOND HALF OF THE WEEKEND THROUGH THE FIRST HALF OF THE
UPCOMING WORK WEEK; HOWEVER, THE MAGNITUDE AND AREAL COVERAGE OF
PRECIPITATION CONTINUES TO DECREASE. LATEST NBM PROBABILITIES FOR
PRECIPITATION AMOUNTS IN EXCESS OF 0.5" GENERALLY RANGE FROM A 20-
50% CHANCE ACROSS MOST OF SOUTHWEST THROUGH NORTH CENTRAL MONTANA,
WITH THE EXCEPTION OF THE BIG BELTS, LITTLE BELTS, MEAGHER COUNTY
VALLEYS, AND JUDITH AND FERGUS COUNTIES WHERE PROBABILITIES RANGE
FROM 50-60%.
AVIATION
31/00Z TAF PERIOD
VFR CONDITIONS PREVAIL THROUGH THE TAF PERIOD WITH MAINLY CLEAR
SKIES EXCEPT FOR SOME AFTERNOON CUMULUS AND PASSING HIGH LEVEL
CLOUDS. SURFACE WINDS WILL ALSO REMAIN RELATIVELY LIGHT UNDER HIGH
PRESSURE AT THE SURFACE AND ALOFT. HOENISCH
REFER TO WEATHER.GOV/ZLC FOR MORE DETAILED REGIONAL
AVIATION WEATHER AND HAZARD INFORMATION.
PRELIMINARY POINT TEMPS/POPS
GTF 51 91 57 74 / 0 0 0 30
CTB 48 89 56 68 / 0 0 10 10
HLN 52 92 57 79 / 0 0 0 40
BZN 46 87 52 79 / 0 0 0 50
WYS 36 79 40 77 / 0 0 0 40
DLN 47 87 51 80 / 0 0 0 50
HVR 48 90 57 73 / 0 0 10 20
LWT 48 84 58 73 / 0 0 10 40
TFX WATCHES/WARNINGS/ADVISORIES
NONE.
HTTP://WWW.WEATHER.GOV/GREATFALLS
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page