Area Forecast Discussion
Issued by NWS Missoula, MT

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
FXUS65 KMSO 310919

Area Forecast Discussion
National Weather Service Missoula MT
319 AM MDT TUE MAY 31 2016

...Prolonged period of above-normal temperatures mid-week through
early next week...

.DISCUSSION...High pressure is building into the western US today,
so today will mark the start of a warming trend. There is enough
moisture that a few mountain showers are possible this afternoon,
otherwise, it will be a very nice and seasonal day. The ridge of
high pressure will flatten a bit on Wednesday due to a weak
shortwave passage. This shortwave will bring enough instability to
portions of north central Idaho and southwest Montana for a few
showers and maybe a thunderstorm or two. High temperatures on
Wednesday are forecast to be around 10 degrees above average,
meaning upper 70s and low 80s in most places. Another shortwave on
Thursday will cause temperatures to be a few degrees cooler than
Wednesday and a few showers will also be possible.

The ridge of high pressure will steadily strengthen over the
Northern Rockies through the weekend. Temperatures should be
running around 20 degrees above normal by Saturday/Sunday, as
highs should be approaching the upper 80s and low 90s for most
valley locations. These readings will be approaching near record
levels for the first week of June. The axis of the ridge appears
to shift to the east by the first part of the week allowing for
southwesterly flow. This flow pattern is conducive to the
development of afternoon/evening showers and thunderstorms.

Given that this will be the first hot streak of the year, it will
be prudent to remind ourselves of common heat safety tips, such as
not leaving pets in cars, staying hydrated, and avoiding strenuous
work during the hottest hours of the day. Even though temperatures
will be hot, the temperatures of area lakes and rivers will still
be relatively cold, so hypothermia can be an issue.


.AVIATION...A few clouds linger near the Divide this morning,
while most of north central Idaho and western Montana have clear
conditions. There is a northeasterly pressure gradient through
much of western Montana so north and east winds of around 8-15 kts
have been common especially in northwest Montana. Simulated
satellite imagery forecast an increase in cloud cover this
afternoon, though, mainly over terrain. A few of the cumulus
clouds this afternoon will become showers over the terrain,
otherwise, building high pressure will bring generally low impact
weather conditions.



$$ is the U.S. government's official web portal to all federal, state and local government web resources and services.