340
FXUS65 KTFX 161134
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
534 AM MDT Tue Jul 16 2024

...AVIATION SECTION UPDATED...

.SYNOPSIS...

High pressure will continue to bring hot and dry weather for the
remainder of the week. Despite occasional shower and thunderstorm
activity, most locations will see little in the way of rainfall
relief.

&&

.DISCUSSION...

The latest satellite and radar analysis depicts an area of
showers and thunderstorms moving southward out of the Canadian
prairies into the Havre area this morning. Hi-res guidance has
this activity fading off around or shortly after sunrise, but the
responsible unsettled northwesterly flow aloft looks to persist
through at least this evening with additional isolated showers and
storms developing along the Rocky Mountain Front and the northern
portion of North- central MT later this afternoon and evening.
There also looks to be sufficient instability over the mountains
south of I90 for isolated thunderstorms this afternoon and
evening. PWATs are highest in the northern areas, running around
0.75 to 0.90 inches, where measurable rainfall will be most
likely, but still mostly less than a tenth of an inch in most
cases. Overall, the primary concern will be gusty winds and
lightning strikes.

High pressure will be the dominant weather feature for much if
not all the week, offering continued very warm to hot
temperatures, mostly dry conditions, and seasonable breeziness;
however, despite the ridge amplification over the coming days,
moisture and shortwaves will make their way up and over the high
pressure system and bring an increase of showers and
thunderstorms, especially Wednesday and Thursday. Sub-cloud layers
look to be dry, so expecting a mix of wet and dry storms at best
and the warm temperatures will ensure round the clock storm
development. This period will need to be closely monitored for
potential fire starts from lightning. As mentioned earlier, the
pattern changes little heading into the weekend, more heat and
mostly dry conditions despite isolated thunder activity. - RCG

&&

.AVIATION...
16/12Z TAF Period

Note: The NWS Great Falls Weather Forecast Office manages the
following TAFs: KCTB, KHVR, KGTF, KLWT, KHLN, KBZN, KEKS and KWYS.

VFR conditions are generally expected over the next 24 hours despite
hazy skies mostly impacting slantwise visibility. An unsettled
northwesterly flow aloft as brought an area of showers and some
thunderstorms to KHVR this morning. This activity should fade over
the next couple of hours, but there will be continued passing
clouds and additional isolated showers and storms this afternoon
along the Rocky Mountain Front and the northern portions of North-
central Montana this afternoon and evening. Some cloud builds and
perhaps a storm or two can also be expected in Southwest MT, mostly
over the higher terrain along the MT/ID border. Winds outside of
showers/storms will be light easterly over the plains and light and
variable in the southwest. Hot temperatures will continue to impact
density altitude each afternoon for the remainder of the week. - RCG

Refer to weather.gov/zlc for more detailed regional aviation
weather and hazard information.

&&

.FIRE WEATHER...

High pressure will continue to bring hot, dry, and seasonably
breezy conditions for the remainder of the week. Minimum relative
humidity values critically low at times with good to moderate
overnight recoveries, lowest at mid- slope locations. Shower and
thunderstorm activity will increase heading towards mid- week, but
little to no rainfall in the presence of lightning and potential
brief gusty winds may result in increased concerns for new fire
starts. - RCG

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  91  60  95  63 /  10  10  10  10
CTB  88  56  92  60 /  20  20  10  20
HLN  94  60  97  63 /   0   0  10  10
BZN  91  55  94  57 /   0   0  10  10
WYS  83  42  84  44 /  20  20  30  10
DLN  88  52  91  55 /   0   0  20  10
HVR  89  60  94  63 /  20  20   0  10
LWT  85  55  89  60 /  20  20   0  10

&&

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

$$

http://www.weather.gov/greatfalls