Area Forecast Discussion
Issued by NWS Great Falls, MT

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FXUS65 KTFX 260935
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
335 AM MDT TUE JUL 26 2016

.DISCUSSION...
Today through Thursday Evening...Quiet conditions this morning,
except for small area of slow-moving showers and weak, pulse-type
thunderstorms through parts of Hill/Chouteau/Blaine counties. This
activity should exit into eastern MT later this morning, with little
rainfall expected. Meanwhile, current water vapor satellite imagery
shows the next Pacific shortwave trof is already into central WA and
is on track to arrive this aftn/eve, bringing another round of
showers and thunderstorms.  Storm coverage should be more widespread
today, especially over the central and Hiline counties, where broad,
moist airmass with dewpoints in the 45 to 58F range is already in
place. Storms should trend a bit wetter today as latest models have
further increased precipitable water (PW) values into the 0.75-1.0
inch range for much of the forecast area. This should lead to more
occurrences of moderate to briefly heavy rainfall as storms move
through our region today.

Pattern repeats itself on Wed as another shortwave tracks across the
Northern Rockies.  PW remain favorably high for decent rainfall
amounts, except for southwest MT where storm coverage and PW values
are forecast to be lower.  The final shortwave in the parade shows
up on Thurs aftn, but this one looks to be the weakest of the three,
with less accompanying moisture too, so storms should be more
isolated in coverage.  Finally, after another day in the upper 80s
to low 90s today, the combination of precip and slightly cooler air
behind the Wed system will provide a brief break in the hot
temperatures.  Look for highs on Wed/Thurs to reach the more
comfortable mid 80s.
Waranauskas

Thursday Night through Tuesday...The last in a series of shortwave
disturbances exits to the east Thursday night. Temperatures trend
back into the lower 90s Friday and Saturday amid a generally stable
westerly flow. However, isolated weak afternoon thundershowers may
be possible during this period over our northeast zones associated
with a weak baroclinic zone. A stronger weather system moves across
the Canadian Rockies Saturday night into Sunday, forcing a southwest
flow aloft over the region. This will help to draw monsoonal
moisture into southwest Montana, with enhanced chances for afternoon
showers and thunderstorms through the weekend. Temperatures trend a
few degrees cooler to start next week with lower heights over the
northwest and isolated to scattered showers. PN

&&

.AVIATION...
Updated 0550Z.

Weak weather disturbance moving east across central/SW MT will
produce isolated thunderstorms through around 09Z. VFR conditions
will prevail otherwise with generally light surface winds and
clearing skies overnight. Thunderstorm activity will increase again
Tuesday afternoon with more widespread coverage anticipated over
North-central MT. PN

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  88  56  85  56 /  40  20  20  30
CTB  82  54  81  53 /  60  40  30  40
HLN  87  61  89  60 /  20  20  10  20
BZN  87  52  87  53 /  10  20  10  20
WEY  81  44  79  44 /  20  20  10  20
DLN  84  52  87  53 /  20  10  10  20
HVR  87  59  84  58 /  30  40  30  40
LWT  81  58  82  57 /  30  30  20  30

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

weather.gov/greatfalls



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