Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 04/25/20
Area Forecast Discussion
National Weather Service Great Falls MT
837 PM MDT Fri Apr 24 2020
.UPDATE...
Inherited forecast reasoning stands true; however, MaxRH was a bit
high for my analysis; therefore, lowered MaxRH throughout most of
the region by about 20% (from about 90%+ to about 70%+). This, of
course, created a cascading effect of necessary adjustments to
Td, POPs, QPF, etc.. While I was at it, tweaked winds and sky
condition to come more in line with current observations, and
interpolated out to a model blend that worked nicely for Saturday.
No changes to the fact that fair and warmer weather with some
gusty winds will dominate Saturday`s weather story.
- Fogleman
&&
.SYNOPSIS...
Fair and mild conditions prevail overnight, with above normal
temperatures over the weekend. Winds will increase by Sunday, with
a windy day expected on Monday along with a warming trend.
Afternoon temperatures could approach 20 degrees above normal on
next Wednesday.
&&
.AVIATION...
Updated 625 PM MDT Fri Apr 24 2020 (25/00Z TAF Period)
Expect VFR conditions throughout this forecast period with one
exception. KHVR may degrade into the MVFR range, intermittently, in -
RA, during the first hour. Additionally, from 25/08Z to 25/14Z
valley fog will obscure some back country LZs. Periods of mountain
obscuration are forecast. Aircraft icing is forecast through 25/18Z.
Expect periods of gusty winds with gusts up to 25 KTS impacting
light aircraft near mountains and in passes. The associated TURBC
is forecast.
- Fogleman
NOTE: Amendments not scheduled for Ennis (KEKS) due to
ongoing runway closure.
&&
.PREV DISCUSSION...
/ISSUED 625 PM MDT Fri Apr 24 2020/
Weak boundary layer instability has led to the growth of
widespread, but shallow cumulus across the region. These clouds
are expected to dissipate tonight, as drier air and rising heights
continue to stabilize the atmosphere. Fair and warmer weather
follows on Saturday, although we`ll start to experience some
increasing southwest winds as the pressure gradient tightens over
the region. A weak shortwave trough and its attendant surface
front will cross the Northern Rockies Saturday night into Sunday.
Some rain or mountain snow showers will be likely up to and along
the Continental Divide Saturday night, but the strong westerly
flow will maintain dry conditions onto the North-central plains.
The westerly flow strengthens behind the departing system on
Sunday. The combination of subsidence and downslope westerly flow
will produce gusty west winds and afternoon relative humidity
values dropping below 20 percent. This will yield at least
elevated fire weather conditions, determined in part by local
variations in moisture content of fine fuels as we begin to green
up. Wind speeds are expected to remain below the high wind warning
criteria of sustained 40 mph or 58 mph gusts, although some wind
prone locations along the Rocky Mountain Front could reach near
these wind speeds. Similar conditions persist into Monday,
although a weak disturbance could push stronger winds into
Southwest Montana.
Broad upper level ridging begins to take hold over the western
U.S. Tuesday and Wednesday, leading to gradually warmer
temperatures. Wednesday still appears likely to be the warmest day
of the week. PN
Thursday and Friday...The airmass starts to become unstable on
Thursday afternoon, as an upper level disturbance moves into the
region from the southwest. There is the potential that a few of
the storms on Thursday could be strong, especially over Southwest
MT. Cooler temperatures start to move back into the region next
Friday, with a small chance for showers continuing. Brusda
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 32 65 42 64 / 0 0 0 0
CTB 33 62 37 60 / 0 0 0 0
HLN 34 67 40 66 / 0 0 10 0
BZN 32 65 38 66 / 0 0 10 0
WYS 22 52 27 57 / 10 0 10 20
DLN 32 62 37 64 / 10 0 10 0
HVR 35 67 44 66 / 0 0 0 0
LWT 32 62 40 62 / 0 0 0 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
http://www.weather.gov/greatfalls