Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/08/23

AREA FORECAST DISCUSSION

National Weather Service Bismarck ND

 957 PM CST Tue Nov 7 2023

.UPDATE...
Issued at 946 PM CST Tue Nov 7 2023

Pesky fog continues to hold on over portions of central North
Dakota this evening. There are a few areas in the Turtle Mountain
region that have dropped down to a quarter mile or less recently.
After collaboration with FGF, we have issued a SPS to cover this
and have added fog to the gridded forecast. The HRRR seems to
have a decent handle on the fog and it looks like with the
approaching low pressure system the fog should clear from west to
east over the next few hours. Already seeing some improvement over
western portions of Bottineau county. With the hopefully
progressive clearing late this evening into the early overnight
hours, we went with the SPS route instead of an Advisory. We have
also updated sky cover to account for more clouds west and slower
clearing east. Also adjusted pops slightly based on latest radar
trends and short term guidance.

UPDATE Issued at 541 PM CST Tue Nov 7 2023

Skies have cleared finally over a good portion of western and
central ND late this afternoon. Eastern portions of the forecast
area are expected to clear through the evening hours as a warm
front continues to move east through the forecast area. Stratus
will then drop south into the forecast area late tonight behind a
trailing cold front. The main forecast changes this evening were
for sky cover, clearing things out this evening then bringing
clouds back down from the north late tonight into Wednesday. A
shortwave over north central Montana is producing some light
returns north of KGGW. May need to take a closer look at the
timing of light precip coming into the northwest later tonight
with the mid evening update.

&&

.SHORT TERM...(This Evening through Wednesday)
Issued at 254 PM CST Tue Nov 7 2023

The short term forecast is highlighted by a cold front bringing
strong northwest winds and chances (20-30%) for light rain and
snow across northern North Dakota late tonight through Wednesday.

This afternoon, the synoptic pattern was characterized by broad
troughing over the western CONUS, with a stronger, embedded
shortwave across the southern Canadian Prairies and Montana,
amplified by weak ridging just east of the forecast area. At the
surface, a warm front extended from a surface low in southern
Alberta, located from Divide County southeast through western Morton
County. Behind the front are clear skies and breezy westerly winds,
while ahead of the front is extensive stratus, cooler temperatures,
and patchy fog.

Highs this afternoon will vary significantly depending on how far
northeast the warm front can make it, with 20 UTC temperatures
ranging from the lower 30s north central to the upper 50s
southwest. Conditions should be mostly quiet through the rest of
today and through this evening, with the exception of some patchy
fog possibly lingering under what stratus remains.

The upper shortwave trough over the southern Canadian Prairies is
expected to close off overnight tonight as the trough base moves
east along the International Border, just north of the forecast
area. The attendant cold front will enter northwest North Dakota
after midnight tonight, moving southeast through the early morning
hours and into daytime Wednesday. For now, it looks like strong
northwest winds along and behind the front will stay just under
advisory criteria, although it will probably be close. Deterministic
guidance is advertising modest pressure rises and cold air advection
with the front, which supports strong winds, although the front
moving through in the morning could work against winds getting
stronger. We are also carrying a chance (20-30%) of rain and snow
across northern North Dakota starting early in the morning and
continuing through most of the day. Impacts look minimal, with only
a few hundreths of liquid expected. Highs on Wednesday will be
cooler in the wake of the front, generally from the upper 30s north
to mid 40s south.

.LONG TERM...(Wednesday Night through Tuesday)
Issued at 254 PM CST Tue Nov 7 2023

The extended forecast is highlighted by overall low chances for
precipitation and warming temperatures into next week.

The closed low and attendant trough quickly move off to the east on
Thursday, with ensemble guidance in good agreement on ridging
building to our west and keeping northwest flow aloft over the
Dakotas to end the work week. We can`t rule out a few embedded
impulses bringing slight chances for precipitation during this time,
but for now blended guidance keeps the forecast area dry. Highs on
Thursday and Friday will be in the mid 30s to mid 40s, with breezy
winds continuing on Thursday in the wake of the cold front.

As we move through the weekend, Saturday looks like a transition day
as flow turns mostly zonal, before a more significant warmup
starting Sunday. Ensemble clusters and NBM temperature
percentiles both give high confidence in a warmup for the start of
next week as broad ridging builds over the central CONUS, with
forecast highs in the mid 40s to mid 50s Sunday through Tuesday.
CIPs analogs and NBM probabilities both advertise very low chances
for precipitation during this period.

&&

.AVIATION...(For the 06Z TAFS through 06Z Wednesday Night)
Issued at 946 PM CST Tue Nov 7 2023

A warm front slowly making its way across the area has provided
enough clearing for VFR conditions at all terminals except KJMS,
which remains socked in with low stratus and MVFR conditions. KJMS
is expected to return to VFR conditions later tonight once the warm
front makes it further east. A surface low pressure system and
associated cold front will sweep across the area late tonight and
through tomorrow, with wrap-around moisture lowering ceilings and
bringing MVFR conditions back to all terminals. Initially southerly
winds will veer westerly as the aforementioned cold front passes
over each terminal, veering more northwesterly behind the front,
with sustained wind speeds increasing to around 20 kts.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

UPDATE...TWH
SHORT TERM...Jones
LONG TERM...Jones
AVIATION...Besson



Area Forecast Discussion

National Weather Service Cheyenne WY

 434 PM MST Tue Nov 7 2023

.SHORT TERM...(Tonight - Wednesday Night)
Issued at 217 PM MST Tue Nov 7 2023

A vigorous mid and upper-level short wave trough & associated cold
front will sweep across the region overnight through early Wed AM,
giving way to scattered rain and show showers across much of south
east Wyo and the western Neb Panhandle through the early afternoon
hours on Wednesday. Activity should remain fairly isolated through
the evening with a substantial uptick in coverage/intensity likely
during the evening/overnight as large scale ascent increases ahead
of the approaching trough axis in the LFQ of a 130 to 140 knot H25
jet, contributing to deep and robust frontogenesis. High-res model
guidance including the HRRR and NAMNest both suggest showers could
become very numerous along the cold front overnight into early Wed
AM as line segments track across across far southeastern Wyoming &
the southern Nebraska Panhandle. After sunset, snow will likely be
the main precipitation type for areas along/W of the Laramie Range
with a rain/snow mix possible into the I-25 corridor possible late
after midnight. Overall, moisture profiles are much too modest for
any notable impacts. However, favorable orographics and strong jet
energy could support a few inches of snowfall accumulation for the
western slopes of the Snowy and Sierra Madre ranges. Expect shower
chances will diminish greatly by 18z Wednesday. Daytime highs will
trend much cooler for Wednesday post-fropa, with breezy conditions
likely in the afternoon.

.LONG TERM...(Thursday - Tuesday)
Issued at 430 AM MST Tue Nov 7 2023

Forecast concerns in the long term deal with strong winds Saturday
through Monday.

Starting off Thursday...Northwest flow prevails as exiting upper
trough moves into the central plains. 700mb temperatures rise from
-8C Thursday morning to -3 to -4C Thursday afternoon. Did go a little
warmer on temperatures over guidance with these warming temperatures
and downsloping off the Laramie Range.

Dry cold front moves into the CWA from the north Friday in the
northwest flow. Front moves through Friday morning with upper
ridging building in behind the front Friday afternoon.

See an increase in winds Friday night into Saturday as yet another
dry shortwave approaches from the west. GFS 700/750mb winds near
40kts Friday evening ahead of the surface front. Winds then climb
to 45-50kts Saturday morning. Craig to Casper 850/700mb height
gradients up near 50mtrs...so wind prone areas could be close to
warning levels Saturday morning through Saturday night.

Winds ease Sunday as Craig to Casper height gradients ease back
down to under 20mtrs. But then they begin to increase once again
Monday.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 424 PM MST Tue Nov 7 2023

A cold front will bring cooler temperatures, a wind shift and a
chance of snow showers overnight tonight.

Wyoming TAFS...Ceilings will vary from 4000 to 12000 feet AGL this
evening, then lower to 2500 feet AGL at Laramie from 06Z to 15Z
with snow showers reducing visibilities to 4 miles from 11Z to
15Z. At Rawlins, snow showers will limit visibilities to 5 miles
and ceilings to 2000 feet AGL from 11Z to 15Z. Thereafter,
scattered to broken ceilings from 5000 to 10000 feet AGL will
occur at all terminals. Winds will gust to 25 knots at all
terminals until 06Z, then to 25 knots at Cheyenne from 12Z to 18Z.

Nebraska TAFS...Scattered to broken ceilings from 4000 to 12000
feet AGL will occur.

&&

.FIRE WEATHER...
Issued at 430 AM MST Tue Nov 7 2023

Ahead of an approaching cold front, temperatures will again be
warm and relative humidity values will drop into the upper teens.
Winds will turn gusty this afternoon as the front approaches from
the west. Some localized pockets of elevated to near-critical fire
weather conditions will be possible this afternoon. Temperatures
will then turn cooler by Wednesday under mostly dry conditions and
overall fire weather concerns will remain low.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&

$$

SHORT TERM...CLH
LONG TERM...GCC
AVIATION...RUBIN
FIRE WEATHER...AW



Area Forecast Discussion

National Weather Service Quad Cities IA IL

 512 PM CST Tue Nov 7 2023

...00z AVIATION UPDATE...

.SHORT TERM...(This afternoon through Wednesday)
Issued at 202 PM CST Tue Nov 7 2023

Key Messages:

1. Scattered rain (25-60%) with a isolated rumble of thunder
possible tonight across northeast IA and northern IL.

2. Challenging high temperature forecast Wednesday, with a large
temperature spread (over 20 degrees) from north to south.

Discussion:

Visible satellite imagery today showed a mix of sun and clouds,
with the lesser amounts seen across northeast MO, southeast IA,
and west central IL. Despite having an easterly or northerly
component to the wind field from the surface up to 850mb per
KDVN/KILX 12z sounding, these areas with less clouds saw
temperatures rise into the lower 60s. Elsewhere, 1 pm
temperatures were 8 to 12 degrees colder with readings generally
in the lower to middle 50s. Early afternoon water vapor imagery
depicts positively tiled trough making its way onshore on the west
coast near San Fransisco. This wave will aid in lifting a warm
front near or across our far southern CWA on Wednesday.

Tonight...increasing WAA and moisture return will bring a chance
of showers to portions of the CWA, with northeast IA and northern
IL favored. A strong LLJ will bring relatively high theta-e air
for early November and PWs around 1 inch prior to midnight. Latest
CAMs and ensemble data suggest scattered showers developing in a
northwest to southeast arc north of a line from Cedar Rapids to
Galesburg and lift northeast. Model soundings and low level RH
progs do suggest that some of the precipitation may fall as virga
and thus lower QPF amounts some. That said, we are only expecting
amounts less than tenth of an inch, as showers will be moving
quite fast through the CWA. In addition, the latest RAP briefly
shows 700-500mb theta-e lapse rates less than zero around 06z so a
rumble or two of thunder will also be possible. Clouds should
keep temperatures warmer overnight tonight, with readings only
dropping into the 40s and lower 50s.

Wednesday...a surface low and associated warm front will track
over Missouri bringing a challenging temperature forecast to the
local area. There remains a lot of spread in how far north this
front will lift, with the 12z GFS the furthest north near the
I-80 corridor and conversely the 12z NAM near La Harpe IL. The 12z
ECMWF has a solution that is in the middle. Of an interesting
note, is that the hi-res Grand Ensemble solution is suggesting a
cooler solution for our CWA, keeping areas north of I-80 largely
in the 40s/50s for much of the day. For now, will go with the
middle of the road approach near the 50th percentile of the NBM,
but a big temperature bust is possible. Areas along and north of
highway 20 may not reach 50 degrees tomorrow, whereas Keokuk
could hit 72 degrees! In addition, forecast soundings show a
drizzle/light rain profile for much of area and with a easterly
flow, could make for a rather raw day outside if the colder
solution verifies.

.LONG TERM...(Wednesday night through Monday)
Issued at 202 PM CST Tue Nov 7 2023

Key Messages:

1. Quiet, dry, and seasonable weather through the rest of the week
and into the weekend.

2. Warmer and breezy next week, with well above normal temperatures.

Discussion:

Wednesday night-Thursday...northerly winds and a drier air mass will
advect into the region with lows dropping into the 30s. Mostly sunny
skies will bring temperatures closer to normal Thursday, with highs
topping out in the low to mid 50s.

The rest of the work week and the weekend will feature a large
surface high drifting east across the northern Plains and the
Midwest, with dry conditions and slightly above normal temperatures.
A low amplitude wave is shown in the latest deterministic runs to
track near the area on Sunday, but will be lacking moisture and only
an increase in clouds is expected at this time.

Next Week...an upper level pattern change from semi-zonal to
southwest flow will occur with increasing temperatures aloft and at
the surface. The 00z ECE and GEFS ensembles show 850mb temps rising
into the 8-10C range by Tuesday night and beyond, which is near the
90th percentile per SPC Climo page. This yields widespread highs in
the middle 60s on the higher end of the NBM guidance and have
trended the forecast towards this solution. While not near record
territory, these values will be 12 to 16 degrees above normal for
the middle of November. Breezy southerly winds will also develop
Tuesday in the return flow.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 510 PM CST Tue Nov 7 2023

Quiet conditions to start the period will deteriorate through the
night ahead of a robust shortwave, which will bring increasing
amounts of low-level moisture and lift into the region. Prompting
much of this increase in moisture will be a robust 40-50 kt
southerly LLJ around 2kft AGL, which is likely to also produce
modest amounts of LLWS through the early morning. Look for VFR
conditions to become MVFR around to just after midnight areawide,
with a threat of scattered rain showers at KDBQ/KMLI/KCID. I`ve
held on to the PROB30 of TSRA for KDBQ as steep lapse rates remain
well advertised in latest forecast soundings, hinting at some
potential for thunder though not a slam dunk.

Once rain showers shift east of the area by about 08/12z, look
for MVFR/IFR cigs to persist through much of the daytime Wednesday
before a shift of winds to the west/northwest brings drier air
into the region late in the TAF cycle.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&

$$

SHORT TERM...Gross
LONG TERM...Gross
AVIATION...Speck



AREA FORECAST DISCUSSION

National Weather Service Sioux Falls SD

 514 PM CST Tue Nov 7 2023

.DISCUSSION...
Issued at 216 PM CST Tue Nov 7 2023

Key Messages:

- Precipitation chances are minimal through the weekend, with just a
low (30% or less) chance of spotty sprinkles/light showers tonight.

- Periods of breezy to windy conditions through Thursday, strongest
during the late morning through mid afternoon. A high chance of
gusts exceeding 25 mph brings elevated fire danger on Thursday.

- Mild highs in the 50s to lower 60s continue Wednesday, but cooler
seasonable highs in the 40s to lower 50s return for the latter half
of the week.

As of mid afternoon, temperatures are slightly cooler than
previously expected thanks to low to mid level stratus overspreading
much of the region. Some recovery well into the 50s and perhaps
lower 60s is still expected for south central South Dakota. In this
area, breaks in cloudiness will combine with the strongest low level
warm air advection just ahead of an inverted sfc trough nosing in
from northeast Colorado.

This evening, occasional light showers or sprinkles are favored near
and east of the Hwy 59 corridor amidst warm air advection slowly
saturating dry mid levels. As the attendant Colorado Low ejects into
western Kansas and the sfc trough meanders eastward, weak sfc high
pressure amidst broad mid to high clouds will make for a mild night
with light winds. Expect lows in the mid 30s to mid 40s. Despite the
cloud cover, HRRR and NAMNest (and HREF) models support fog
development early Wednesday morning, favored near and north of the I-
90 corridor. Have added patchy fog to forecast where it is most
likely in the James River Valley, but this may need to be expanded
south and east.

On Wednesday, efficient mixing through a stout 925mb nocturnal
inversion (8 to 12C) will keep near to slightly above normal high
temperatures in the 50s. This should help erode early morning clouds
but will also make for a breezy day with northwesterly gusts into
the 20s and 30s. Did decrease gusts from the NBM to a NBM/CONSShort
blend. Wednesday brings the last of the "warmth" until early next
week. Cold air advection aloft takes hold by Wednesday evening with
clearing skies behind the passing upper trough axis bringing
Wednesday night lows near to below the freezing mark.

Northwesterly to northerly flow aloft brings near to cooler than
normal weather Thursday through Saturday. Despite cooler
conditions, significantly drier air funnels in behind the departed
upper trough axis on Thursday, meaning dew points in the teens to
mid 20s. Some model guidance (primarily NAM) suggests stronger
gusts Thursday than Wednesday, perhaps exceeding 40 mph. This
combination of stronger winds combined with drier air will make
elevated fire danger on Thursday afternoon. Dry weather is favored
through Sunday, though a few minor shortwaves sliding through
would suggest a nonzero chance of period of a light rain or snow.
High confidence in warmer weather returning next week with broad
ridging favored across the Central U.S.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening)
Issued at 512 PM CST Tue Nov 7 2023

Mainly VFR expected through the period. Some patchy MVFR ceilings
will be possible this evening. Later tonight a little fog will be
possible in the mid James Valley but confidence is marginal.
Otherwise winds will be gusty Wednesday afternoon with gusts
around 25 to 30 knots.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
IA...None.
NE...None.
&&

$$

DISCUSSION...BP
AVIATION...08



Area Forecast Discussion

National Weather Service Missoula MT

 1257 PM MST Tue Nov 7 2023

.DISCUSSION...This afternoon, radar imagery reveals showers
moving into the region, with downslope drying effects occurring in
areas like the northern Bitterroot, Missoula, and Mission
valleys. Southwesterly winds aloft are causing these showers to
weaken before reaching the valleys. High-resolution models predict
intensifying showers as the afternoon and evening progress,
accompanied by a shift in winds to the west and northwest,
reducing downsloping effects.

Some high-resolution models suggest heavier snow showers
developing this evening over Lookout and Lolo passes. This,
coupled with cooling temperatures, raises concerns about snow-
covered roadways and low visibility. The HRRR model is
particularly aggressive with the showers, which, if accurate,
could lead to lingering travel impacts even after the showers
subside. Showers, some forming into bands, are expected to persist
into the night, with temperatures cooling enough to allow
isolated light accumulations in valley locations.

In the backcountry, including the Clearwater Mountains and Swan,
Whitefish, and Bitterroot ranges, snow accumulations of
approximately 4-6 additional inches are anticipated.

A brief ridge of high pressure will build in on Thursday and
early Friday, potentially creating conditions for valley fog,
given recent moisture.

Models are somewhat divided on a shortwave trough`s strength and
timing moving through the region on Friday. An earlier arrival
would increase the likelihood of widespread light snow.


&&

.AVIATION...Widespread rain showers will continue to traverse the
Northern Rockies through the rest of the afternoon, obscuring
mountain tops around the region. Southwesterly winds are currently
downsloping these showers in area valleys, reducing impacts due
to the showers. Later this evening and overnight, the wind
direction throughout the profile is expected to turn more
westerly. At the same time, some hi-resolution models, in
particularly the HRRR, are indicating more intense showers/bands
developing over west-central and southwest Montana. With cooling
temperatures, rain will switch to snow, potentially reducing
ceilings and visibility for KMSO, KHRF, and KBTM. Light
accumulations may be the result, but probabilities for receiving
an inch or more is quite low, below 10%.



&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

$$