Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 04/23/20
Area Forecast Discussion
National Weather Service Springfield MO
1058 PM CDT Wed Apr 22 2020
.SHORT TERM...(This evening through Thursday)
Issued at 238 PM CDT Wed Apr 22 2020
Widespread showers and embedded thunderstorms continued through
most of the day, with the bulk of the heaviest rainfall and
lightning from Joplin to Springfield to Branson and points
southwest. Latest 18Z AMDAR aircraft sounding out of Tulsa, OK has
shown a slight increase in elevated instability along with plenty
of effective shear and steeper lapse rates, therefore will likely
continue to see some isolated storms develop to the southwest and
move northeast towards the area late this afternoon and evening.
Instability decreases with northeast extent therefore the highest
chance for an isolated strong storm with hail would be south of a
Joplin to West Plains line. Model guidance has been way too warm
with temps today with most places staying in the middle 50s once
rain began, also limiting instability.
This is all attributed to a compact upper level low moving through
southern KS and northern OK. A 110kt upper level jet was nosing
into southeast Oklahoma, clearing providing the area with plenty
of lift. Surface low was south of Norman, Ok and will move east-
east northeast. Therefore it now looks likely that the low track
will go just south of the area in northern AR. PW values from
AMDAR soundings have been around 1.2in therefore locally heavy
rainfall and isolated flooding will be possible this evening and
overnight. Storm total rainfall from this event (including whats
already fallen will be between 1-2 inches with the highest amounts
in far southwest Missouri.
Gusty winds of 30-35mph will continue ahead of the low this
evening and then behind the low by Thursday morning. Rain may not
exit the eastern Ozarks until late morning or early afternoon. The
remainder of Thursday will feature decreasing clouds by afternoon
with highs in the 60s.
.LONG TERM...(Thursday Night through Wednesday)
Issued at 238 PM CDT Wed Apr 22 2020
Quick on the heels is another system arriving from the northwest
Thursday night into Friday morning. An upper level trough will
move in during the day Friday with rain developing and remaining
during most of Friday. Another instability is present for general
storms with nothing severe expected. Rain may linger into early
Saturday before decreasing. Total rainfall amounts with this
system look to be between 0.5 and 1 inch. This could cause
localized flooding especially as grounds will be more saturated
from prev rain today/tonight.
Northwest flow continues Sunday into next week. Sunday looks
generally dry however models bring down a few pieces of energy
Monday and again by mid week that may provide for more light rain
chances however confidence is low with these systems next week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1055 PM CDT Wed Apr 22 2020
An area of surface low pressure will move across northern
Arkansas tonight into Thursday. Showers will occur at times north
of the low across southeastern Kansas and the Missouri Ozarks
through the overnight hours into early Thursday morning. MVFR to
IFR conditions will be possible tonight into Thursday morning.
Gusty northwesterly winds will also occur north of the low
especially on Thursday.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
SHORT TERM...Burchfield
LONG TERM...Burchfield
AVIATION...Wise
Area Forecast Discussion
National Weather Service Great Falls MT
733 PM MDT Wed Apr 22 2020
.SYNOPSIS...
Showers will develop by this evening over the Rocky Mountain
Front and spread eastward overnight. Expect scattered showers to
continue for Thursday and Friday, with an isolated thunderstorm
possible on Thursday. It turns drier and mild again over the
weekend.
&&
.Evening Update...
Update has been published, with some adjustments made to PoPs and
QPF to account for latest model guidance and radar trends. In
addition, updated hourlies to account for latest observations.
Mid- to upper level moisture continues to increase across the
Northern Rockies this evening per recent water vapor imagery and
evening sounding data; however, the aforementioned evening sounding
did exhibit a pronounced layer of dry air (surface to approximately
7000ft agl) in the low levels. This dry air in the low levels will
likely lead to virga/sprinkles with any initial shower(s) this
evening, but as the evening progresses and the lower levels
saturate, more precipitation will then begin to reach the surface.
Shower activity this evening and tonight over the plains and valleys
of the region will range from isolated to scattered in nature, with
the best coverage along and southwest of a Cut Bank, to Fort Benton,
to Lewistown line and north of the Interstate 90 corridor.
The mountains can expect numerous showers during the overnight
hours, with a rain/snow mix this evening becoming all snow near the
midnight hour. Outside of the United States Highway 89 corridor
through the Little Belt Mountains (i.e. Kings Hill Pass) where snow
accumulations of 2 to 4 inches are expected, the majority of the
accumulating snow is expected to remain above pass levels (some
accumulations are also possible on road surfaces across far Western
Beaverhead County) tonight. We will address the potential for some
localized slippery spots over/near Kings Hill Pass tonight with a
Special Weather Statement, but otherwise no winter weather
highlights are currently planned or anticipated. - Moldan
&&
.AVIATION...
Updated 615 PM MDT Wed Apr 22 2020 (23/00Z TAF Period)
Begin this TAF period with VFR conditions at all airfields. Most
stations will become MVFR in -RA and/or -SN BR and lowering CIG.
KWYS may fall into the IFR range. Mountain obscurations are
forecast. Additionally, aircraft ICG will impact aviation. Gusty
winds will mostly impact light aircraft near mountains and in
passes. Expect the associated TURBC. After 23/18Z thunderstorm
activity may pass through far southwest Montana impacting aviation
for an area that would include KWYS.
- Fogleman
NOTE: Amendments not scheduled for Ennis (KEKS) due to ongoing
runway closure.
&&
.HYDROLOGY...
The latest guidance from the River Forecast Center have lowered
and delayed the crests of snow melt runoff draining from the Bears
Paw Mountain into Clear Creek, and from the Cypress Hills moving
through Lodge Creek. Although flooding is no longer expected along
these streams, confidence is low while snow remains in the upper
reaches of these drainages. Property owners along Clear Creek and
Lodge Creek should continue to remain prepared for possible rises
in the water level onto stream crossings or low lying land
adjacent to the creek.
&&
.PREV DISCUSSION...
/ISSUED 620 PM MDT Wed Apr 22 2020/
Satellite imagery reveals a ragged Chinook Arch extending across
portions of central Montana. A robust surface pressure gradient
continues to drive gust west to southwest winds. There have been
some stable, capped boundary layer cumulus clouds, gradually
mixing out as those gusty winds mix down from the west.
Expect clouds to continue increasing tonight. A shortwave trough
embedded in the strong westerly flow aloft will cross the Northern
Rockies later this evening. Precipitation moves up to the
Continental Divide overnight, with widespread rain and mountain
snow showers spreading across Central and Southwest Montana
through Thursday. Snow levels are expected to remain generally
above about 5500 to 6000 feet, so at or above most mountain
passes. One exception is Kings Hill Pass, which could receive a
couple inches of snow accumulation through Thursday morning.
Showers continue through the day Thursday, but there is just
enough instability behind the passing shortwave to produce up to
about 300 J/Kg Cape. This may be just enough for a few rumbles of
thunder, mainly over the higher terrain of central and Southwest
Montana Thursday afternoon. Showers continue, but decrease in
activity Thursday night as the flow splits and another week
shortwave moves through southern Alberta.
Isolated rain showers will remain in the forecast during the day
Friday, with a decreasing trend as high pressure builds from the
west. As high pressure establishes overhead Friday night,
decreasing clouds will allow for some valleys across western
Montana to approach freezing early Saturday morning. Saturday
afternoon will be another nice Spring day, though clouds will be
on the increase late in the day, as our next weather system moves
in.
Forecast models continue to trend toward a mild week ahead, but
active in terms of windy conditions or periods of showers or
thunderstorms.
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 41 55 37 59 / 50 50 30 30
CTB 39 56 36 58 / 20 20 10 10
HLN 43 55 36 60 / 40 50 20 20
BZN 38 54 33 57 / 40 90 50 30
WYS 24 45 23 48 / 50 90 50 40
DLN 38 53 32 55 / 20 40 20 10
HVR 43 61 38 61 / 30 30 40 30
LWT 38 52 35 54 / 40 50 50 50
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
http://www.weather.gov/greatfalls