Area Forecast Discussion
Issued by NWS Great Falls, MT

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FXUS65 KTFX 191752
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
1152 AM MDT TUE JUL 19 2016

AVIATION SECTION UPDATED

.DISCUSSION...

Today...Update to zones not planned...The air mass will become
unstable again this afternoon and isolated thunderstorms are again
expected. Most unstable and best shear found across the northeast
zones...Blaine and Fergus counties. Zelzer

&&

.AVIATION...
UPDATED 1751Z.

Central and Southwest Montana remain underneath unsettled southwest
flow aloft. The air mass will be especially unstable across
northeast eastern portions of the region, including KLWT, where
large hail and gusty winds are possible this evening. VFR conditions
will prevail through the next 24 hours.

&&

.PREV DISCUSSION...
/ISSUED /
Today through Thursday...Upper level trough remains along the
Washington/Oregon coast through the short term period. As noted
yesterday, flow aloft over central and southwest Montana will depend
on the relative strength and position of the upper level ridge
currently over the Great Plains. Latest model runs have increased
the amount of monsoon moisture and instability for today so
isolated/scattered thunderstorms are possible once again this
afternoon and evening and possibly again on Wednesday. Latest model
runs are currently keeping Thursday generally dry.
Temperatures will be quite warm today, but cool a degree or two on
Wednesday. However, they rebound again on Thursday as the axis of
upper level ridging attempts to build over the Four Corners
region. Breezy conditions are likely across portions of the
forecast area and could cause borderline fire weather concerns
when combined with hot temperatures and low RH. However, forecast
fire dangers remain low enough that no highlights are required at
this time. mpj

Thursday night through Tuesday...A weak upper level disturbance will
move across northern Montana early Friday through Friday night. This
disturbance will temporary knock down the upper level ridge over the
Upper Midwest and allow for scattered thunderstorms to develop over
portions of Central and North Central MT. Most of the storms should
come to an end by late Friday night. The upper level ridge will then
shift to the Southwest US over the weekend and then start to shift
northward towards southern MT by early next week. Overall, mostly
dry conditions are expected over much of the region from Saturday
through Tuesday. With the upper level disturbance moving through
Friday, afternoon temperatures will fall back to near normal for
both Friday and Saturday and then start to warm a few degrees above
normal Sunday through early next week. As of now, the upper level
ridge is not expected to build too far north next week, but if the
upper level ridge does build further northward towards central MT
early next week, wide spread afternoon temperatures in the upper 90s
to around 100 degrees would become more likely over our region. We
will just have to monitor the strength of the ridge and how far it
pushes northward early next week, with some adjustments in
temperatures possible. Brusda

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  90  55  87  54 /  10  10  10  10
CTB  83  52  81  49 /   0  10  10  10
HLN  92  59  89  58 /  10  20  10   0
BZN  95  53  90  50 /  10  10  10   0
WEY  80  46  79  43 /   0   0   0   0
DLN  88  52  86  50 /   0  10   0   0
HVR  91  58  87  54 /  10  20  10  10
LWT  89  56  85  55 /  10  20  10  10

&&

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

$$

weather.gov/greatfalls


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