649
FXUS65 KTFX 032353
AFDTFX
Area Forecast Discussion
National Weather Service Great Falls MT
553 PM MDT Tue Jun 3 2025
Aviation Section Updated.
.KEY MESSAGES...
- Daily chances for showers and storms through the work week,
with the highest coverage of showers and storms expected today
and Wednesday.
- Below normal temperatures through Wednesday will gradually warm
to above normal temperatures by the end of the work week with
warmer temperatures lasting through at least early next week.
- Predominately light winds are expected through Thursday.
&&
.DISCUSSION...
/Issued 231 PM MDT Tue Jun 3 2025/
- Meteorological Overview:
Moist, and unstable, northwest flow aloft will help to support daily
chances for showers and thunderstorms across much of Southwest
through North Central Montana through the remainder of the work
week. Within this northwest flow subtle shortwaves, specifically
today and Wednesday, will help to provide the "best coverage" for
showers and storms as compared to Thursday and Friday when coverage
will be more isolated to widely scattered in nature. With H700-H500
temperatures running anywhere 1 to 2.5 standard deviations below
normal through Wednesday will support an environment conducive for
cold air funnels, especially over the plains of Central and North
Central Montana where surface heating will be the strongest in
conjuction with the coldest air aloft. High temperatures will remain
below normal through Wednesday, with temperatures moderating back
above normal through the remainder of the work week.
Transient upper level ridging then looks to overspread the Northern
Rockies through the weekend and Monday before being flattened and
replaced with predominately zonal flow. This aforementioned ridging
will bring generally dry conditions to much of the Northern Rockies
over the weekend; however, and isolated shower or storm can`t be
ruled out over the mountains. Temperatures continue to moderate
through the weekend, with well above normal temperatures expected as
highs peak in the mid-70s to mid-80s. -Moldan
- Forecast Confidence & Scenarios:
Rainfall Today and Wednesday:
In general, showers will remain light across the region through
Tuesday afternoon. However, HREF guidance still shows the potential
for some stronger storms to develop which could bring rainfall rates
of 0.10" or greater west of the I-15 corridor (20-40%) with lower
probabilities (10-30%) along the Island Ranges.
On Wednesday, the HREF shifts its focus for heavier precipitation
more towards the Island Ranges and particularly the Little Belts.
Wednesday afternoon could see another round of isolated to
scattered afternoon thunderstorms with some potential for some
heavier downpours. At this time there is a low potential for
severe weather for both Tuesday and Wednesday. However, an
isolated stronger storm cannot be ruled out.
Warmer Temperatures Next Week:
The ECMWF EFI has been strongly hinting towards well above normal
temperatures returning by Sunday and lasting through at least
Monday. Currently the NBM has a 40-60% of highs exceeding 90
degrees along portions of north-central Montana including Havre,
Shelby, Fort Benton, and Great Falls. Tuesday is expected to be
slightly cooler however there is still a 10-30% chance for the
same locations exceeding 90 degrees. The good news is, at this
point in time, good overnight temperature recovery is expected
with lows dipping into the 50s. Thus, the concerns for prolonged
heat are minimal at this time. -thor
&&
.AVIATION...
04/00Z TAF Period
Scattered showers and a few thunderstorms are expected through
the evening hours, most numerous over Central/North-central
Montana. This activity will begin to slowly diminish after 04/04Z
with at least some lighter end showers persisting into the
overnight hours. Brief periods of low VFR conditions can be
expected during times of precipitation and northwesterly winds
will gust over 25 kts at times this evening. Patchy fog may
develop late tonight into Wednesday morning in places that undergo
partial clearing, but widespread impacts are not anticipated at
this time. Continued northwesterly flow aloft will bring another
round of scattered primarily afternoon and evening showers and
thunderstorms on Wednesday. - RCG
Refer to weather.gov/zlc for more detailed regional aviation
weather and hazard information.
&&
.HYDROLOGY...
The Gallatin River, specifically at Logan, continues to run near
or above Action Stage thanks to increased snowmelt and recent
precipitation across the Madison and Gallatin Ranges in Southwest
Montana. Latest river forecasts from the Missouri Basin River
Forecast Center (MBRFC) keeps the Gallatin River below Minor Flood
Stage at all forecast points, but users and those with interest
along the river should be prepared for increased spring flows. -
Moldan
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 65 40 67 42 / 30 50 30 10
CTB 61 38 66 39 / 40 60 20 10
HLN 66 42 70 44 / 20 40 30 10
BZN 63 37 67 39 / 10 40 10 10
WYS 58 29 62 30 / 10 30 10 10
DLN 61 37 64 37 / 10 20 0 0
HVR 68 39 70 42 / 40 50 20 10
LWT 62 37 62 41 / 20 40 50 20
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
http://www.weather.gov/greatfalls
