736
FXUS65 KTFX 091815
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
1215 PM MDT Thu May 9 2024

...Aviation Section Update...

.SYNOPSIS...
Lingering shower activity will continue to diminish and end
heading into the afternoon hours. Much drier and milder conditions
are then expected for the weekend, but a passing disturbance will
bring some breeziness and a slight chance of a few showers and
perhaps a thunderstorm to the plains Saturday night into Sunday.
Additional weather disturbances are expected to pass through the
Northern Rockies early next week and bring unsettled conditions,
but temperatures look to remain at or above average.

&&

.UPDATE...
Updated forecast is out. The main adjustment this morning was to
increase Pops in the Great Falls area. Light rain is falling along
a deformation zone that has set up with the upper level ridge
building in from the west and low pressure to our southeast.
Precipitation is light, but never the less continues to fall. The
forecast models diminish this light precip this evening.
Otherwise, temperatures look on track for today, with a nice
warming trend expected over the weekend. Brusda

&&

.AVIATION...
1215 PM MDT Thu May 9 2024 (09/18Z 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 prevail for the duration of this TAF period for most
of our airfields. The exceptions are: KGTF - MVFR conditions are
forecast, intermittently, for the first hour this TAF period due to
low ceiling; KLWT - MVFR conditions are predominant until 09/23Z,
due to low ceiling; and KBZN - MVFR conditions through 09/22Z due to
predominant low ceiling. Patchy areas of fog/mist are forecast
during the overnight period, tonight. Visibility through mountain
valleys and passes may be poor, due to fog. Mountain obscuration
should be expected, especially through this afternoon. Generally,
light to breezy northwesterly to northeasterly winds are forecast.
- Fogleman

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

&&

.HYDROLOGY...
The flood warning will continue for Clear Creek. The water is
receding on the creek, but it will just take a bit more time before
the water levels go below flood stage.

The areal flood advisory has been replaced with a flood watch for
small streams and creeks that flow out of the Bears Paw Mountains
this weekend. In talking with emergency managers in this area this
morning, most creeks have receded from the recent rainfall. However,
warm temperatures are expected to develop on Friday and then
continue through the weekend. This could result in small streams and
creeks that flow out of the Bears Paw Mountains to come out of their
banks once again. Thus a flood watch has been issued for this area
for that potential.

Additionally, with warm temperatures expected elsewhere over the CWA
from Friday through Sunday, expect small streams and creeks that
flow out of the mountains of the remainder of North Central and
Southwest MT to begin to rise as well. Since many of these streams
and creeks are at lower levels, the threat/impact from any flooding
that could develop is lower at this time. Never the less, we will
continue to monitor the situation and should the potential for
flooding increase elsewhere over the CWA additional flood statements
might need to be issued over the weekend. Brusda

&&

.PREV DISCUSSION...
/ISSUED 550 AM MDT Thu May 9 2024/

Abundant low level cloudiness, areas of showers, and even some
patchy fog can be found over North-central and Southwest Montana
this morning. Northeasterly flow aloft will more or less hang
around for one more day before the responsible low pressure system
weakens further and moves away from the region tonight. Scattered
showers are expected to be light and will diminish and end in a
northeast to southwest fashion as the day progresses. Temperatures
begin moderate from the chilly last couple of days, but will
still run slightly below average, especially over central and
southwestern locations where clouds will linger for much of the
day. No significant note worthies for tonight aside from some
patchy fog in spots with light winds and lingering moisture in
place amid partial clearing.

Ridging attempts to build in heading towards the weekend, but
there will still be a bit of a northwesterly flow aloft, leaving
an opportunity for a weak shortwave and cold front to pass through
the plains Saturday night into Sunday. This system will merely
bring some breeziness, a few clouds, and lower end shower and
isolated thunderstorm chances. The warming trend will generally be
uninterrupted with afternoon highs climbing well into the 70s by
Sunday.

Ensembles remain in fairly good agreement with another more
defined shortwave and cold front passing through Monday into
Tuesday, bringing more breeziness and scattered showers and
isolated thunderstorms to much of North-central and Southwest
Montana. Most suites favor a northwesterly flow aloft continuing
for the second half of next week, with about two thirds of them
favoring ridging to be more dominant and only a minority of
guidance leaning towards troughing and unsettled conditions. At
this time, there`s nothing really out of line from what`s normally
expected this time of year and temperatures look to run at least
near average even with the wetter model solutions. - RCG

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  56  33  66  40 /  80   0   0   0
CTB  59  31  71  44 /   0   0   0   0
HLN  55  36  69  43 /  40   0   0   0
BZN  51  31  65  35 /  50  10   0   0
WYS  50  25  63  28 /  30  10   0   0
DLN  54  33  66  37 /  30   0   0   0
HVR  64  38  70  43 /  20   0   0   0
LWT  49  31  60  37 /  50  10   0   0

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Flood highlights are in effect for portions of North Central MT.

&&

$$

http://www.weather.gov/greatfalls