752
FXUS65 KTFX 102335
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
535 PM MDT FRI MAY 10 2024
AVIATION SECTION UPDATED
SYNOPSIS
UPPER LEVEL RIDGING WILL RESULT IN ABOVE AVERAGE TEMPERATURES
ACROSS THE REGION THIS WEEKEND. WEAK DISTURBANCES MOVING THROUGH THE
RIDGE WILL RESULT IN ISOLATED SHOWERS AND PERHAPS A FEW
THUNDERSTORMS IN THE AFTERNOON THIS WEEKEND, MAINLY NEAR TERRAIN AND
ACROSS NORTH-CENTRAL MONTANA. FLOODING CONCERNS WILL REMAIN IN AREAS
WHERE SIGNIFICANT SNOWMELT IS OCCURRING.
DISCUSSION
THROUGH SUNDAY... AN UPPER LEVEL RIDGE WILL SLOWLY SHIFT EASTWARD
FROM THE WEST COAST TOWARD THE CENTRAL CONUS THIS WEEKEND, ALLOWING
FOR TEMPERATURES TO CLIMB BACK ABOVE AVERAGE IN MOST AREAS. ALTHOUGH
TEMPERATURES WILL WARM AT THE SURFACE, A RELATIVELY COOL
NORTHWESTERLY FLOW WILL BE IN PLACE ALOFT. THIS WILL COMBINE WITH A
WEAK DISTURBANCE TO RESULT IN ISOLATED TO WIDELY SCATTERED SHOWERS
AND THUNDERSTORMS, PRIMARILY ACROSS NORTH-CENTRAL MONTANA, LATE
SATURDAY EVENING INTO SUNDAY. ISOLATED AFTERNOON SHOWERS WILL BE
AROUND NEAR TERRAIN THIS WEEKEND, BUT THE PROBABILITY OF THESE AT
ANY ONE LOCATION IS QUITE LOW AT THIS POINT. -AM
MONDAY THROUGH TUESDAY...ENSEMBLE CLUSTERS ARE IN RELATIVELY GOOD
AGREEMENT WITH A SHORTWAVE WITHIN INITIALLY ZONAL FLOW, AND AN
ASSOCIATED PACIFIC FRONT, DIGGING EAST/SOUTHWEST AND OVER/ACROSS THE
NORTHERN ROCKIES DURING THE PERIOD. HIGH TEMPERATURES AHEAD OF THE
SHORTWAVE AND PACIFIC FRONT ON MONDAY WILL ONCE AGAIN WARM WELL
ABOVE NORMAL AND INTO THE 70S, BUT FALL BACK BELOW NORMAL AND INTO
THE 60S ON TUESDAY. SURFACE WINDS WILL BE ON THE INCREASE THROUGH
THE MORNING HOURS ON MONDAY AHEAD OF THE AFOREMENTIONED PACIFIC
FRONT, BECOMING BREEZY AND GUSTY DURING THE AFTERNOON AND EVENING
HOURS ON MONDAY. WHILE THE LATEST NBM PROBABILISTIC DATA DOES NOT
SUPPORT HIGH WINDS MATERIALIZING OVER THIS TIMEFRAME; MOST LOWER
ELEVATIONS ACROSS SOUTHWEST THROUGH NORTH CENTRAL MONTANA HAVE
BETWEEN A 20-50% CHANCE OF SEEING WIND GUSTS IN EXCESS OF 35KTS.
LIGHT PRECIPITATION IS ALSO EXPECTED TO ACCOMPANY AND FOLLOW THE
PASSAGE OF THE PACIFIC FRONT MONDAY AFTERNOON/NIGHT, LINGERING INTO
THE DAY ON TUESDAY AS THE UPPER LEVEL DISTURBANCE DIGS INTO THE
CENTRAL ROCKIES. WHILE WIDESPREAD, HEAVY PRECIPITATION IS NOT
EXPECTED OVER THIS TIMEFRAME, NBM PROBABILISTIC DATA DOES SUPPORT
BETWEEN A 40-70% CHANCE FOR QPF AMOUNTS TO REACH OR EXCEED 0.10"
ACROSS MOST OF SOUTHWEST THROUGH NORTH CENTRAL MONTANA.
WEDNESDAY THROUGH NEXT FRIDAY...ENSEMBLE CLUSTERS DIVERGE
DRASTICALLY THROUGHOUT THE PERIOD, WITH THE MAIN DIFFERENCE BETWEEN
THE CLUSTERS BEING THE TIMING OF SHORTWAVE RIDGING AND TROUGHING.
THE MULTI-MODEL ENSEMBLE FAVORS A MORE ZONAL PATTERN, WITH
TEMPERATURES NEAR NORMAL AND DAILY CHANCES FOR SHOWERS. - MOLDAN
AVIATION
530 PM MDT FRI MAY 10 2024 (11/00Z TAF PERIOD)
VFR CONDITIONS WILL PREVAIL OVER THE CWA THROUGH PERIOD. EXPECT
PASSING HIGH CLOUDS TO MOVE FROM NORTH TO SOUTH THROUGH THE CWA
THROUGH THE PERIOD. OTHERWISE, NO OTHER AVIATION IMPACTS ARE
EXPECTED AT THIS TIME. BRUSDA/THOR
REFER TO WEATHER.GOV/ZLC FOR MORE DETAILED REGIONAL AVIATION
WEATHER AND HAZARD INFORMATION.
HYDROLOGY
A FLOOD WARNING REMAINS IN EFFECT FOR CLEAR CREEK IN NORTH CENTRAL
MONTANA THROUGH SATURDAY MORNING, WITH WATER LEVELS EXPECTED TO
SLOWLY FALL FROM MINOR FLOOD STAGE TO ACTION STAGE OVER THIS
TIMEFRAME. ADDITIONALLY, A FLOOD WATCH REMAINS IN EFFECT FOR THE
NEARBY BEARS PAW MOUNTAINS FROM THIS AFTERNOON THROUGH THE WEEKEND
AS WARMING TEMPERATURES AND SUBSEQUENT SNOWMELT RUNOFF, AND
REMAINING RUNOFF FROM RAINWATER, COULD PUSH CREEKS AND STREAMS OUT
OF THEIR BANKS.
FURTHER SOUTH ACROSS THE ISLAND RANGES OF CENTRAL MONTANA (I.E.
HIGHWOOD, MOCCASIN, JUDITH, LITTLE BELT, AND SNOWY), INCREASED
SNOWMELT AND SUBSEQUENT RUNOFF INTO CREEKS AND STREAMS IS EXPECTED
FROM SATURDAY THROUGH MONDAY AS OVERNIGHT TEMPERATURES AND DEWPOINT
TEMPERATURES REMAIN ABOVE FREEZING. THIS RUNOFF COULD RESULT IN
WATERWAYS NEARING BANKFUL BY SATURDAY NIGHT/SUNDAY MORNING. HENCE,
A FLOOD WATCH HAS BEEN ISSUED FOR THE LITTLE BELTS EASTWARD
TOWARD THE LEWISTOWN AREA. - MOLDAN/AM
PRELIMINARY POINT TEMPS/POPS
GTF 44 78 45 79 / 0 0 20 20
CTB 47 78 44 79 / 0 10 20 20
HLN 42 79 50 81 / 0 0 0 0
BZN 34 75 43 77 / 0 0 0 10
WYS 29 67 34 69 / 10 10 0 10
DLN 37 73 42 76 / 0 0 0 0
HVR 46 79 47 77 / 0 0 40 20
LWT 40 72 44 71 / 0 0 30 40
TFX WATCHES/WARNINGS/ADVISORIES
FLOOD WATCH THROUGH SUNDAY MORNING FOR BEARS PAW MOUNTAINS AND
SOUTHERN BLAINE.
FLOOD WATCH FROM SATURDAY AFTERNOON THROUGH MONDAY MORNING FOR
CASCADE COUNTY BELOW 5000FT-FERGUS COUNTY BELOW 4500FT-JUDITH
BASIN COUNTY AND JUDITH GAP-LITTLE BELT AND HIGHWOOD MOUNTAINS-
MEAGHER COUNTY VALLEYS-SNOWY AND JUDITH MOUNTAINS-WESTERN AND
CENTRAL CHOUTEAU COUNTY.
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