Area Forecast Discussion
Issued by NWS Missoula, MT

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FXUS65 KMSO 242050

Area Forecast Discussion
National Weather Service Missoula MT
250 PM MDT Fri May 24 2019

.DISCUSSION...Widespread showers and thunderstorms have developed
over the Northern Rockies this afternoon. These storms are slow
moving and able to produce moderate to heavy rainfall rates,
causing localized ponding and rapid rises of small streams. The
precipitation will shift to northwest Montana tonight as an upper
level low pressure system shifts southward.

The models are still indicating that the upper level pattern will
still be conducive for another round of showers and thunderstorms
on Saturday afternoon. The storms across southwest Montana and
Lemhi county could become fairly strong with the capability of
producing small hail and gusty winds. And once again the
precipitation will shift up into northwest Montana Saturday night.
Temperatures for Saturday appear to remain 5 to 10 degrees below
normal for this time of year.

A closed low pressure circulation over the Great Basin will continue
to spin moisture northward over the Northern Rockies during
Sunday and Monday, with showers and thunderstorms present mainly
during the afternoon and evening hours each day. Some models
suggest that a concentrated plume of moisture will move along and
east of the Continental Divide during this time, with rainfall
amounts approaching nearly an inch total near Glacier Park.
Temperatures will trend slowly upward throughout the week.

Models are trending toward showers continuing to be present during
each afternoon and evening Tuesday to Thursday, as opposed to the
high pressure previously depicted. Thunderstorm potential comes
back into play on Thursday. Precipitation amounts appear minimal
each day, but the cloudiness will definitely be palpable each

By the end of next week and through the weekend, a series of weak
storm systems will move over the Northern Rockies and continue to
increase daily shower and thunderstorm activity. Temperatures
will trend a bit below the seasonal average late next week as


.AVIATION...Numerous showers and thunderstorms have developed over
the Northern Rockies affecting all terminals. The convection
should be diminishing near KBTM and KSMN around 25/03z and by KMSO
around 25/05z. KGPI appears to be impacted by showers throughout
the night. Another round of numerous showers and thunderstorms is
anticipated for Saturday afternoon and evening. These storms will
be capable of reducing ceilings and visibilities for periods of



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