034
FXUS65 KGGW 060544
AFDGGW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
1144 PM MDT SUN JUL 5 2026
KEY MESSAGES
- THE A WARM FRONTAL SYSTEM WILL APPROACH THE AREA WITH MORE
WIDESPREAD THUNDERSTORMS LATE MONDAY NIGHT AND CONTINUE THROUGH
TUESDAY NIGHT. ISOLATED SEVERE STORMS ARE POSSIBLE BUT HEAVY
FOCUSED RAINFALL IS THE MAIN CONCERN.
- UNSETTLED WEATHER WILL LIKELY CONTINUE THROUGH THURSDAY.
- EXPECT HIGHS TO BEGIN REACHING THE 90S FRIDAY THROUGH THE
WEEKEND WITH AN ISOLATED 100 POSSIBLE SATURDAY.
DISCUSSION
WEATHER PATTERN OVERVIEW:
TODAY: MOST MORNING SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
EXIT THE AREA AROUND 2 TO 4AM LEAVING A PARTLY CLOUDY DAY WITH
INCREASING CLOUD COVER FROM THE SOUTHWEST IN THE LATE AFTERNOON
AS A WARM FRONT APPROACHES.
A VERY AGGRESSIVE SHORTWAVE WILL APPROACH ALONG A GRADUALLY SLOPED
WARM FRONT ON SOUTHWEST FLOW ALOFT MONDAY NIGHT INTO TUESDAY
NIGHT. THIS WILL PROVIDE DYNAMIC FORCING FOR ASCENT IN A MOISTURE
RICH ENVIRONMENT. PRECIPITABLE WATER AMOUNTS WILL RANGE FROM 1.0"
TO 1.5" DURING THESE PERIODS WHICH RANKS IN THE TOP 90TH
PERCENTILE. SCATTERED THUNDERSTORMS AND WIDESPREAD RAIN SHOWERS
ARE EXPECTED. GIVEN THE FLASH FLOODING THAT HAS OCCURRED IN
JUNE/EARLIER THIS WEEK ACROSS AREA, THE GROUND IS CLOSING IN ON
SATURATED. THUS, THIS PERIOD WILL NEED TO BE MONITORED FOR NOT
ONLY AN ISOLATED SEVERE RISK, BUT THE POTENTIAL IMPACTS
COMPOUNDING FROM ADDITIONAL HEAVY RAINFALL.
MAIN CONCERNS TO WATCH FOR WILL BE ANY SHARP FRONTAL GRADIENTS
THAT PROVIDE FOCUS TO LIFT AND TRAINING THUNDERSTORMS. CURRENTLY
WITH THE WARM FRONT'S GRADUAL SLOPE THIS DOES NOT LOOK TO BE THE
CASE. BUT, MESOSCALE BOUNDARIES COULD BEGIN TO FORM UP WHERE NOT
PREVIOUSLY ANTICIPATED... IN WHICH CASE A FLASH FLOOD WATCH MAY
NEED TO BE CONSIDERED UNDER SUCH SHARP BOUNDARIES IN SUCH A HIGH
PW ATMOSPHERE.
ENSEMBLES SHOW A CONTINUING PROGRESSIVE WEATHER PATTERN UNFOLDING
WITH A SHORTWAVE WEDNESDAY INTO THURSDAY.
THURSDAY NIGHT INTO THE WEEKEND MAIN RIDGE ACROSS THE
INTERMOUNTAIN WEST BEGINS TO STRENGTHEN AND DRAGS 90S FOR HIGHS
INTO THE REGION AND SOME SUPPRESSION FOR SHOWERS AND
THUNDERSTORMS. HOWEVER NORTHEAST MONTANA REMAINS ON THE PERIPHERY
OF THIS RIDGE WHICH COULD REINTRODUCE A NEW SHORTWAVE RATHER THAN
CLEAR SKIES AT ANY TIME WASHING OUT SOME OF THE DRIER CONDITION
CONFIDENCE IN THE ENSEMBLES.
FORECAST CONFIDENCE & DEVIATIONS:
DEVIATIONS INCLUDE... INTRODUCED A CAMS BLEND OF NPOPS, WIND, AND
WINDGUSTS, TO MATCH UP WITH OBSERVATIONS/RADAR/SATELLITE WHERE NBM
WAS CRITICALLY INACCURATE FOR HOURLY DATA OUT TO ABOUT 15Z IN
ORDER TO ACCOUNT FOR THE COLD FRONT, SHORTWAVE, RAIN AND THUNDER
MOVING THROUGH THIS MORNING.
CONFIDENCE IS MODERATE TO HIGH THROUGH THURSDAY, BUT THEN FUZZES
OUT TO MODERATE TO LOW FRIDAY ONWARD.
GAH
AVIATION
LAST UPDATED: 0500Z
FLIGHT CATEGORY: MVFR - VFR
DISCUSSION: EARLY MORNING SHOWERS AND THUNDERSTORMS ARE EXPECTED
TO EXIT THE AREA AROUND 08 TO 09Z LEAVING DRY CONDITIONS AND SCT
MID TO HIGH CLOUDS THROUGH MOST OF THE REST OF THE CYCLE. A NEW
ROUND OF SHOWERS AND THUNDERSTORMS ARE EXPECTED TO ENTER FROM THE
SOUTHWEST MONDAY NIGHT AROUND 06-12Z AND HANG ON TILL EARLY
WEDNESDAY MORNING.
WIND: N AT 10 TO 15 KTS THROUGH THE DAY. VEERING NE AND E MONDAY
EVENING AND DECREASING TO AROUND 10 KTS THROUGH MONDAY NIGHT.
GAH
GGW WATCHES/WARNINGS/ADVISORIES
NONE.
WEATHER.GOV/GLASGOW
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