043
FXUS65 KMSO 190804
AFDMSO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
204 AM MDT SUN JUL 19 2026
DISCUSSION
KEY MESSAGES:
- ELEVATED FIRE WEATHER CONDITIONS TODAY DUE TO HOT, DRY, AND
BREEZY CONDITIONS, ESPECIALLY IN NORTHWEST MONTANA.
- ANOTHER SURGE OF MONSOON MOISTURE IS EXPECTED TO ARRIVE BY
TUESDAY, INCREASING CLOUD COVER AND THUNDERSTORM CHANCES.
WATER VAPOR SATELLITE IMAGERY SHOW MUCH DRIER AIR MOVING IN FROM
THE WEST, WHICH WILL BRING LOW RELATIVE HUMIDITY THIS AFTERNOON.
ALONG WITH THE DRY AIRMASS, A STRENGTHENING PRESSURE GRADIENT WILL
BRING INCREASING WESTERLY WINDS ACROSS WESTERN MONTANA AND NORTH-
CENTRAL IDAHO. THIS WILL TRANSLATE TO ELEVATED FIRE WEATHER
CONDITIONS, ESPECIALLY ACROSS WESTERN MONTANA. CURRENTLY, THERE IS
A 40 PERCENT PROBABILITY THAT WIND GUSTS WILL RANGE BETWEEN 20
AND 25 MPH, WITH AFTERNOON HUMIDITY VALUES FALLING TO 15 TO 20
PERCENT.
ON MONDAY, A RIDGE OF HIGH PRESSURE BUILDS OVER THE WESTERN U.S. AND BEGINS
TO PULL UP MONSOON MOISTURE FROM THE SOUTHWEST. INITIALLY, THE MOISTURE
WILL BRING MOSTLY CLOUD COVER. BY TUESDAY AND WEDNESDAY, AVAILABLE PRECIPITABLE
WATER ANOMALIES WILL RISE TO 200 TO 250 PERCENT OF NORMAL. THIS MOISTURE,
COUPLED WITH AN INCOMING SHORTWAVE TROUGH, WILL INITIATE THE DEVELOPMENT OF
SCATTERED SHOWERS AND THUNDERSTORMS, ESPECIALLY OVER WEST-CENTRAL AND
SOUTHWEST MONTANA, AS WELL AS NORTH-CENTRAL IDAHO. THESE STORMS WILL BRING
PERIODS OF STRONG, GUSTY, ERRATIC WINDS, BRIEF HEAVY RAINFALL, AND FREQUENT
LIGHTNING. THESE STORMS WILL BE SIMILAR TO WHAT THE REGION EXPERIENCED OVER
THE PAST THREE DAYS.
BY THE END OF THE WEEK AND NEXT WEEKEND, THE CENTER OF THE HIGH PRESSURE
SYSTEM WILL SHIFT OVER THE NORTHERN PLAINS, OPENING THE DOOR TO INCREASING
WESTERLY WINDS IN THE MIDDLE OF THE ATMOSPHERE OVER THE NORTHERN ROCKIES.
TEMPERATURES WILL RUN 10 TO 15 DEGREES ABOVE NORMAL ALONG WITH DRY
CONDITIONS.
AVIATION
WATER VAPOR SATELLITE IMAGERY SHOW MUCH DRIER AIR MOVING IN FROM
THE WEST ACROSS THE NORTHERN ROCKIES THIS MORNING. THE DRY AIR
WILL LIMIT ANY CONVECTION DEVELOPMENT, THOUGH WINDS WILL INCREASE
OUT OF THE WEST, WITH GUSTS RANGING BETWEEN 20 TO 25 KNOTS.
TEMPERATURES WILL RUN 5 TO 10 DEGREES ABOVE NORMAL FOR THIS TIME
OF THE YEAR.
MSO WATCHES/WARNINGS/ADVISORIES
MT...NONE.
ID...NONE.
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