807
FXUS65 KMSO 150727
AFDMSO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
127 AM MDT WED JUL 15 2026
DISCUSSION
KEY MESSAGES:
- THUNDERSTORMS ARE IN THE FORECAST THROUGH THE WEEK FOR MUCH OF
WESTERN MONTANA AND PORTIONS OF CENTRAL IDAHO. STORMS WILL
CONTINUE IN SOUTHWEST MONTANA THROUGH THE WEEKEND.
- DRYING TREND THROUGH THE WEEKEND
SATELLITE IMAGERY EARLY THIS MORNING INDICATES A BROAD RIDGE OF
HIGH PRESSURE OVER THE CENTRAL U.S. AND A LOW PRESSURE CIRCULATION
OFF THE COAST OF THE PACIFIC NORTHWEST. THE NORTHERN ROCKIES IS
STUCK IN THE MIDDLE, UNDER SOUTHWEST FLOW ALOFT. TWO VISIBLE
MOISTURE SOURCES ARE ALSO VISIBLE ON SATELLITE IMAGERY, ONE FEED
OF PACIFIC MOISTURE FROM THE SOUTHWEST, AND ANOTHER FEED OF
MONSOONAL MOISTURE FROM THE SOUTH. AS A RESULT, PRECIPITABLE
WATER STAYS ABOVE AVERAGE FOR THE ENTIRE FORECAST AREA GOING INTO
THE WEEKEND. WITH LITTLE LARGE-SCALE FORCING FOR ASCENT, THIS
MOISTURE FEED WILL REMAIN IN THE FORM OF CLOUDS AND INCREASED
RELATIVE HUMIDITY.
SMALLER SCALE ASCENT IN THE FORM OF CONVECTION WILL BRING SOME
CHANCES FOR PRECIPITATION. WHILE AMPLE SHEAR AND MOISTURE WILL BE
AVAILABLE, CLEARING SKIES EARLY IN THE DAY COULD CREATE ENOUGH
INSTABILITY TO FUEL AFTERNOON/EVENING THUNDERSTORMS. A DRY LOWER
ATMOSPHERE STILL INDICATES THAT THE BIGGEST THREAT FROM
THUNDERSTORMS WILL BE ERRATIC, GUSTY OUTFLOW WINDS. LIGHTNING,
BRIEF HEAVY RAIN, AND SMALL HAIL WILL ALSO BE PRESENT WITH ANY
STORM THAT IS ABLE TO FORM THIS AFTERNOON.
THE POTENTIAL FOR AFTERNOON THUNDERSTORMS WILL REMAIN THROUGH AT
LEAST FRIDAY. ON SATURDAY, THE PACIFIC LOW PRESSURE SYSTEM MOVES
NORTH OF OUR REGION AND THE FLOW FLATTENS TO A DRIER, WESTERLY
FLOW WITH DECREASED INSTABILITY. THE CHANCES OF AFTERNOON SHOWERS
AND THUNDERSTORMS MAY BE CONFINED TO SOUTHWEST MT. ADDITIONALLY,
AS THE GRADIENT BETWEEN LOW PRESSURE IN CANADA AND HIGH PRESSURE
RIDGE IN THE DESERT SOUTHWEST INCREASES, EXPECT A BREEZY
AFTERNOON.
AVIATION
EXPECT MOSTLY VFR FLYING CONDITIONS TODAY WITH A
COUPLE EXCEPTIONS. THE FIRST EXCEPTION WILL BE POSSIBLE FOG AT
KGPI THIS MORNING. YESTERDAY’S RAIN INTRODUCED ENOUGH MOISTURE FOR
FOG FORMATION IF SKIES CLEAR BEFORE SUNRISE. THERE’S NOT ENOUGH
CONFIDENCE IN CLOUDS LIFTING, SO NO FOG IS MENTIONED IN THE
15/0600Z TAF. THE SECOND EXCEPTION TO VFR TODAY WILL BE CHANCES
FOR CONVECTION AT KBTM, KSMN, AND POSSIBLY KHRF. KEEPING MENTION
OF THUNDERSTORMS IN THE TAFS THIS MORNING DUE TO INSTABILITY,
MOISTURE, AND SHEAR. IF CLOUD COVER PERSISTS ALL DAY, CHANCES FOR
CONVECTION WILL BE DIMINISHED THIS AFTERNOON.
MSO WATCHES/WARNINGS/ADVISORIES
MT...NONE.
ID...NONE.
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