Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/17/21

Area Forecast Discussion

National Weather Service Bismarck ND

 931 PM CST Tue Nov 16 2021

.UPDATE...
Issued at 931 PM CST Tue Nov 16 2021

Overall the forecast is trending well, but we did increase gridded
forecast wind speeds tonight and Wednesday morning in this update,
and have chosen to advertise gusts to 65 mph in our messaging. The
00 UTC NAM and HRRR cycles through its 02 UTC iteration continue
simulating mixing to about 800 mb through the night thanks to cold
air advection behind a secondary cold frontal passage taking place
this evening. That cold air advection will also promote low-level
subsidence, supporting momentum transfer within the well-mixed
boundary layer that has peak winds around 55 kt at times thanks to
the intensifying low- and midlevel height gradient. Otherwise, we
will need to monitor how far south of the international border
the deformation-related snow shield in southern Canada is able to
survive overnight, too.

UPDATE Issued at 617 PM CST Tue Nov 16 2021

We allowed the Red Flag Warning to expire as scheduled at 00 UTC,
and are making no changes to wind headlines at this time. Early
this evening, the highest observed winds are in northwestern ND,
where low- to midlevel flow is strongest (e.g., 850 mb winds on
the order of 50 kt) in closer proximity to the intense low over
southern Canada, marked by a minimum MSLP of ~984 mb in vicinity
of Yorkton, Saskatchewan. Guidance is consistent in calling for
low-level wind fields to strengthen further south and east over
western and central ND overnight as that low shifts east, and
forecast soundings suggest the boundary layer will remain well-
mixed amidst cold air advection. If recent HRRR forecasts prove
correct we may actually need to increase forecast gusts across
central ND with a later update. For now, all we did was blend
recent observed trends in the forecast, with one exception being
that we did spread the chance of snow further south into western
ND late tonight and Wednesday morning.

&&

.SHORT TERM...(This evening through Wednesday)
Issued at 228 PM CST Tue Nov 16 2021

Current analysis places deep stacked low pressure system over
southeastern Saskatchewan. At the surface, cold front is now
pushing through eastern North Dakota. In its wake, tight pressure
gradient exists with cold air advection, resulting in strong and
gusty winds. In addition, the airmass pushing in is very dry,
resulting in critical fire weather conditions over southwest and
far south central portions of the state.

For tonight, stacked upper low continues on an eastward track,
passing along just to the north of the international border. A
secondary cold front works its way through the area overnight.
Along with ushering in even colder air, this will lead to low
clouds sliding over, and some light snow possibly developing over
northern areas. Accumulations are doubtful, and if do occur will
be minimal at best. Winds behind the secondary front will switch
more northwesterly, with the stronger winds spreading east.

On Wednesday, winds continue as stacked low gradually works its
way into southwestern Ontario. Forecast soundings still suggest
some stronger winds mixing down resulting in high gusts, so will
leave current high wind warning in place. Snow chances diminish
over most of the north in the morning, with maybe a little snow
lingering over the Turtle Mountains in the afternoon.

Winds ease up Wednesday evening as pressure gradient relaxes, and
surface ridging starts to work in.

.LONG TERM...(Thursday through Tuesday)
Issued at 228 PM CST Tue Nov 16 2021

Weak ridging expected to end the week, bringing a modest warming
trend returning temperatures to around average. A clipper quickly
zips through on Sunday. This looks to be mainly dry at this point,
but if it were to shift west a bit a little precipitation will be
possible. The main impact at this point looks to be increased
winds and dropping temperatures.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 931 PM CST Tue Nov 16 2021

Strong west to northwest winds gusting to around 50 kt will be the
primary aviation concern through the 00 UTC TAF cycle. Initially,
the strongest winds will be over western ND, but they will spread
into central ND overnight and continue area-wide Wednesday. MVFR
ceilings will also spread north to south across the area tonight
and linger into Wednesday as a strong low pressure system slowly
moves across southern Canada. A chance of light snow exists west
and north tonight and Wednesday, as well.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
High Wind Warning until 6 PM CST /5 PM MST/ Wednesday for
NDZ001>003-009>011-017>021-031>034-040>045.

High Wind Warning until 6 PM CST Wednesday for NDZ004-005-012-
013-022-023-025-035>037-046>048-050-051.

Wind Advisory until midnight CST tonight for NDZ004-012-022-035-
036-046-047-050.

&&

$$

UPDATE...CJS
SHORT TERM...JJS
LONG TERM...JJS
AVIATION...CJS



Area Forecast Discussion

National Weather Service Boston/Norton MA

 1017 PM EST Tue Nov 16 2021

.SYNOPSIS...
A rather chilly night is expected tonight as high pressure settles
over Southern New England. A warm front passing to our north on
Wednesday will bring about a warming trend but will be accompanied
by considerable cloudiness. Thursday will be quite warm and
breezy but a cold front will bring showers Thursday night. High
pressure brings dry and colder weather Friday and Saturday. As
the high moves offshore and a strong low pressure system in the
Great Lakes moves toward New England, rain may develop late
Sunday and rain is likely on Monday.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
1010 PM Update:

Increased sky cover a bit for a good portion of the night across
the Berkshires, portions of the CT Valley into Windham County in
CT and also raised temps in areas underneath these clouds. Also
utilized bias-corrected HRRR temps to adjust temps somewhat.

Forecast challenge tonight will be on low temperatures. While
skies are mainly clear for most of SNE, infrared satellite
shows a rather narrow but persistent band of Lake- Ontario
enhanced cloudiness that trails across eastern NY thru the
Berkshires/CT Valley to near Willimantic CT. Latest guidance
indicates this cloud band will move little over the next few
hours before lifting north by late-overnight/pre-dawn. While
winds in the interior and northern MA have gone light, winds
around 10 mph near the eastern MA coast and into Cape Cod are
also leading to somewhat milder temps here (in the 40s). Any
clearing and easing of winds will lead to otherwise strong
radiational cooling, but may not necessarily be that persistent
and there could be a pretty large range in temps over small
distances. Urban areas and the coasts should be milder than
elsewhere in the interior, in the mid to upper 30s. Areas that
see clear/calm conditions last the longest could radiate down
into the mid to upper 20s.

Previous discussion...

From the late evening on, a ridge of high pressure will build
eastward into into the region from the west. Cloud cover
dissipates, leaving clear skies. The weakening pressure
gradient allows NW winds to become light, favoring good
radiational cooling during the overnight hours.

Enough of a lingering NW gradient should keep coastal areas less
cold than locales further away from the shoreline. Expecting
overnight lows in the mid 20s to low 30s, except 30s along the
shoreline.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
Wednesday:

Ridge axis is short lived over our area, moving to the east early in
the day. Warm advection pattern brings an increase in mid and high
clouds with an approaching warm front. These clouds should dampen
somewhat the extent of diurnal heating, however a mild rebound in
temperatures are forecast, with highs in the upper 40s to mid 50s,
escept some mid 40s in the east slopes of the Berkshires.

Wednesday Night:

A milder night on tap as warm front continues to cross the area.
Continued warm advection brings mainly a thickening of clouds, but
can`t rule out a few scattered showers with the warm front. Given
weak forcing and marginal moisture, thinking most locales will stay
dry. The airmass change as well as addition of clouds will mean a
noticeably warmer night. Expecting overnight lows in the 40s.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Highlights...

* Quite warm Thursday
* Dry and colder Friday and Saturday
* Chance of rain Sunday and rain likely Monday
* Still watching for the potential for coastal low developement
  later Monday into Tuesday

Details...

Thursday...

Thursday will be the pick of the week, with sunshine and
temperatures climbing to 65 to 70 degrees in northern CT, RI,
and eastern MA and 60 to 65 in northwest MA. Dewpoints will
climb into the mid 50s in eastern MA. A low level jet will lead
to breezy conditions, perhaps with gusts to 20-30 mph,
especially in eastern sections. Late in the afternoon, clouds
will increase in western sections in advance of a cold front.

Thursday night...

A cold front will sweep across southern New England. A band of
showers is expected to accompany this front. We tried to see if
there is any possibility of severe weather, but this does not
appear to be anything like what happened last Saturday. There
will be a low level jet of 50-55 kt at 850 mb in place and
forecast 0-1km helicity of 200+ in RI and southeast MA. However,
there is virtually no 0-3 km CAPE at 03Z Fri and only a spot of
10-20 J/kg of CAPE around Buzzards Bay at 06Z Fri. K Indices
remain below 30. So, do not have thunder in the forecast...just
showers. Temperatures will plunge to the lower 30s behind the
front, and it`s possible that there is a coating of snow in the
higher elevations of the east slopes of the Berkshires as the
precipitation ends by daybreak Friday.

Friday and Saturday...

Strong high pressure in the Ohio Valley on Friday moves east and
becomes centered over southern New England on Saturday. The
upper trough will still bring some mid-level cloudiness to
northern MA on Friday. Clear skies are expected Friday night and
sunny skies on Saturday. It will be much colder, with highs both
days mainly in the 40s...except near 50 near Cape Cod/Islands.

Sunday/Sunday night...

High pressure moves offshore and a southerly flow sets up,
bringing a return of moisture and cloudy skies. There could be
some light rain showers or drizzle forming by Sunday night.

Monday/Tuesday...

A very strong upper level low pressure system is forecast to
move out of the Great Lakes and across New England by Tuesday.
There is a high level of uncertainty in the evolution of this
system at the surface. Many model runs have backed off on the
idea of an intense secondary low pressure developing just to
our south and now depict the primary low passing to our north,
with a very strong cold front moving across the region. That
would bring heavy rain showers, possibly ending as some snow in
the higher terrain. Operational GFS and ECMWF runs are in this
camp, as are their respective ensembles, but the Canadian
remains in the previous strong low camp. This is way too early
to try to resolve. At this point, we have rain likely Monday and
a chance of rain Tuesday, with possibly some snow in the higher
elevations Tuesday. Stay tuned.

&&

.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.

21Z Update...

Through 00Z: High confidence.

VFR, with CIGs ~050 at times over the interior. WNW winds 10-20 kt,
with gusts 20-25 kt continuing until sundown.

Tonight: High confidence.

VFR, with patchy CIGs BKN050 possible over the interior through 02Z.
WNW winds 5-10 kt become light after 06z.

Wednesday: High confidence.

VFR. Increasing coverage of mid to high clouds after 16z as a warm
front moves across southern New England. Expected to be a dry
frontal passage. Winds become S/SW under 10 kt.

Wednesday Night: Moderate confidence.

BKN cloud cover lingers, with low VFR to MVFR CIGs possible. S wind
5-15 kts.

KBOS Terminal...High Confidence in TAF.

KBDL Terminal...High Confidence in TAF.

Outlook /Thursday through Sunday/...

Thursday: VFR. Breezy.

Thursday Night: Mainly MVFR, with areas VFR possible. Windy
with local gusts up to 30 kt. RA likely, chance SHRA.

Friday: VFR. Breezy. Chance RA.

Friday Night: VFR. Breezy.

Saturday through Saturday Night: VFR.

Sunday: VFR. Slight chance RA.

&&

.MARINE...
Forecaster Confidence Levels.

Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.

Tonight: High confidence.

SCA headlines were dropped for Boston Harbor/Narragansett Bay,
and continue into the overnight for the remainder of the coastal
waters.

Winds and seas continue to decrease through the evening. While SCA-
level gusts continue on most nearshore and offshore waters early, NW
gusts to subside to 15-20 kt by early Wed morning. By daybreak Wed,
seas decrease to around 2 ft or less nearshore, to 3-4 ft offshore.

Wednesday: High confidence.

Winds lighten and become S early Wednesday, then increase to around
15 to 20 kt in gusts by late in the day. Seas 3 ft or less all
waters.

Wednesday Night: Moderate confidence.

S winds strengthen to 10-20 kts, with gusts to 25 kts possible. Seas
at 2-3 feet to start, then may build to 3-5 feet on the outer
waters. SCA headlines may be needed.

Outlook /Thursday through Sunday/...

Thursday: Moderate risk for Small Craft Advisory winds with
gusts up to 25 kt. Seas up to 5 ft.

Thursday Night: Moderate risk for Small Craft Advisory winds
with gusts up to 30 kt. Rough seas up to 9 ft. Rain likely,
chance of rain showers.

Friday: Moderate risk for Small Craft Advisory winds with gusts
up to 25 kt. Rough seas up to 8 ft. Chance of rain.

Friday Night: Moderate risk for Small Craft Advisory winds with
gusts up to 25 kt. Areas of rough seas.

Saturday: Winds less than 25 kt. Areas of seas approaching
5 ft.

Saturday Night: Winds less than 25 kt.

Sunday: Winds less than 25 kt. Seas locally approaching 5 ft.
Chance of rain.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 1 AM EST Wednesday for ANZ231>235-
     237-251-256.
     Small Craft Advisory until 7 AM EST Wednesday for ANZ250-254-
     255.

&&

$$
SYNOPSIS...NMB/GAF
NEAR TERM...Loconto/NMB/GAF
SHORT TERM...NMB
LONG TERM...GAF
AVIATION...Loconto/NMB/GAF
MARINE...Loconto/NMB/GAF



Area Forecast Discussion

National Weather Service Grand Junction CO

 430 PM MST Tue Nov 16 2021

.SHORT TERM...(Tonight through Wednesday night)
Issued at 222 PM MST Tue Nov 16 2021

Satellite imagery paints a vivid picture of the closed, Canadian
low and its tight circulation, currently spinning over
Saskatchewan. It`s broad trough draped over the Rocky Mountains
and leading jet axis have drawn a stream of moisture stretching
from the southern tip of the SoCal coast, all the way across the
Northern Plains. Pacific moisture absorbed in southwest flow have
supported the blanket of mid to high level clouds stretched across
the forecast area. However, as of late, clearing has worked its
way into northeast Utah and northwest Colorado ahead of the
trough`s trailing cold front. As the evening evolves, the base of
the trough`s axis will shift east and pull the cold front across
the Western Slope. Though the bulk of moisture tied to this system
will remain well north of the forecast area, remnants from a weak
Atmospheric River event have already reached the northern ranges
in northwest Colorado, allowing light snow to reach the ground
over higher peaks. Expect moisture content to improve through this
evening, and enhanced lift from the frontal passage will generate
the highest snowfall rates through 06Z. Discrepancies between
HiRes guidance`s available QPF still leaves some uncertainty with
tonight`s accumulation. The HRRR has consistently lagged the
NAMnest with regard to available moisture. Recent HRRR runs have,
at best, 0.1 to 0.2 inches of total precip forecast exclusively
over the Park Range. In contrast, the NAMnest has been a bit
beefier, with up to an inch of total precip atop the Park Range
as well as accumulation over surrounding ranges. Despite even the
short term disparity, WPC`s guidance has remained consistent,
leaving the Park Range peaking at roughly 0.3 inches across the
highest peaks (similar to the HRRR), but with a greater spatial
distribution of available precip (more in line with NAMnest). End
result remains with 1 to 3 inches over the Park Range, with snow
amounts tapering off closer to an inch for the Elkhead and Flat
Tops. As such, expect limited impacts, focused over mountain pass
(i.e. Rabbit Ears, Gore and Vail Pass).

Aside from snowfall and clouds encompassing the northern ranges-
down to Independence Pass- the rest of the forecast area will
start eroding through the cloud layer due to mixing just ahead of
the front and the entire system`s eastward progression. West to
northwest flow encompasses the CWA by Wed morning with a cold air
mass sinking as far south as the Four Corners by sunrise.
Temperatures will run below normal across the northern half of the
forecast area. However, a weaker thermal gradient over the Four
Corners region will limit the cold front`s influence on daily
highs. Areas generally south of I-70 will see a drop in
temperatures, roughly 3 to 5 degrees, but will remain at or just
above seasonal norms.

All lingering snow showers and cloud cover dwindle Wednesday
afternoon, as a transient ridge builds overhead. Despite high
clouds spilling over the dirty ridge, forecast lows continue to
show a sharp dip overnight.

.LONG TERM...(Thursday through Tuesday)
Issued at 222 PM MST Tue Nov 16 2021

Strong cold air advection behind the departing trough will result
in some of the coldest readings we`ve seen this fall come
Thursday morning. Lows are expected to drop into the 20s for many
lower central and southern valleys with teens and single digits
over the higher valleys near Craig, Steamboat, Gunnison and Aspen.
A cold morning will quickly give way to increasing high clouds as
the shortwave ridge of high pressure slides overhead and yet
another Pacific system crashes into the PacNW coast. This active
northern stream will flatten the ridge, resulting in a dirty zonal
flow across the western slope. Some light orographic snow may
occur over the Park Range through the end of the week in this
persistent westerly flow but not much in the way of appreciable
accumulation expected. A shortwave cuts across the northern
Rockies late Saturday into Sunday morning, for better chances of
snow over the Park Range and Elkheads but amounts appear
inconsequential at this time. Confidence is fairly low due to the
complex nature of resolving these subtle shortwaves and orographic
influences.

A strong ridge of high pressure then builds over the west and slides
over the region Sunday through early next week. There is much
discrepancy beyond Monday in terms of what next week holds based on
the influence from a cut off low that develops over SoCal. The GFS
wants to bring this low inland as an open wave across the Four
Corners by Tuesday with widespread precipitation, whereas the ECMWF
keeps the low cut off and tracking south of the Four Corners,
leaving our CWA dry. Time will tell but leaning towards the drier
solution for now as models have a hard time resolving cut off lows
and tend to be a bit too progressive with them. Temperatures should
rebound late this week into the weekend with highs a few degrees
above normal given high pressure and increasing high cloud cover.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 426 PM MST Tue Nov 16 2021

High level SCT to BKN cloud cover continues to move east out of
the area, with clearing already occurring for KVEL, KCNY, KGJT,
and KRIL. While the upper level clouds have cleared KHDN, low CIGS
will continue through the night there, leading to terrain
obstruction. Otherwise, all sites should see clear skies by
tomorrow morning, and VFR conditions are expected for the next 24
hours. Some gusty winds will possible into the evening hours
wherever skies have already cleared, but should diminish
overnight.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...
CO...None.
UT...None.
&&

$$

SHORT TERM...ERW
LONG TERM...MDA
AVIATION...TGJT



Area Forecast Discussion

National Weather Service Lincoln IL

 748 PM CST Tue Nov 16 2021

.SYNOPSIS...
Issued at 748 PM CST Tue Nov 16 2021

Breezy and mild weather will prevail over central and southeast
Illinois overnight. However, the arrival of a cold front will
result in falling temperatures across the area on Wednesday.
Expect periods of light rain as this front crosses the area,
although amounts should be less than a quarter of an inch.

&&

.UPDATE...
Issued at 748 PM CST Tue Nov 16 2021

Warm air surge has begun into our area this evening, with wind
gusts around 30 mph reaching near I-72. By midnight, most of the
forecast area should see temperatures around 60 degrees. The cold
front is currently approaching central Iowa, and should be closing
in the Peoria metro around sunrise and Champaign/Decatur toward
midday. Some updates have been sent to adjust the precipitation
trends a bit slower on the onset. Some minor adjustments were also
made with the temperature trends, though overall they are still on
track.

&&

.SHORT TERM...(This evening through Wednesday)
ISSUED AT 231 PM CST Tue Nov 16 2021

The dominant feature impacting the forecast through the short term
period is an occluded 984 mb surface low located over Saskatchewan
this afternoon. Locally, a warm front has gradually lifted
northward across southern Illinois today. While temperatures are
still above average across the area, they`re a few degrees cooler
than was initially forecast as cirrus and a slower northward
progression of the warm front have limited the warming. The
forecast temperatures for the remainder of the afternoon were
adjusted accordingly. The warm front will continue to lift north
this evening, and breezy southerly flow in the warm sector will
persist into the overnight hours, resulting in a mild night. Cloud
cover will increase from south to north after sunset as a strong
low level jet (925 mb winds approaching 45-50 knots) advects warm
air and moisture northward. Temperatures may be coldest just
after sunset, then hold steady or even warm a few degrees through
the night. Mixing will be limited overnight, but should still be
sufficient to mix down occasional gusts of 25-30 mph.

The cold front associated with the Canadian low pressure system
will push into the area early Wednesday morning, with a swath of
scattered rain expected along the frontal zone. Light rain or
drizzle is expected to begin around midnight west of the Illinois
River, and spread east to the I-55 corridor by sunrise. The cold
front will continue to push southeast through the day, producing a
sharp temperature gradient across the area. Areas ahead of the
front will remain near 60, while areas behind the front drop into
the low 50s or upper 40s during the day. Southerly winds ahead of
the front remain breezy, gusting up to 35 mph. Total rainfall
amounts from the system will be light, about a quarter inch or
less.

&&

.LONG TERM...(Wednesday night through Tuesday)
ISSUED AT 231 PM CST Tue Nov 16 2021

The front should depart by Wednesday evening, with a few showers
lingering in eastern Illinois through the evening. Behind the
front, northwest flow will advect cooler air into the region. On
Thursday, winds remain breezy as the pressure gradient between the
departing low and building high pressure over the Plains will be
sufficient to produce sustained northwest winds of 15-20 mph and
gusts up to 30 mph. Highs will only be in the 40s, and wind chill
values will struggle to reach the mid 30s through the day. As the
surface high pressure ridge shifts over the area Thursday night
the winds will finally weaken. Thursday night should be the
coldest night through this weekend, as the surface high pressure
results in clear skies and light winds, allowing temperatures to
drop into the low 20s.

Temperatures remain cool on Friday, in the low 40s, with cloud
cover increasing in response to DPVA from a weak shortwave. By
Saturday, high pressure shifts off towards the east coast, and
southerly flow results in temperatures returning to more
seasonable values with highs near 50. Precip chances return late
in the weekend as a weak frontal boundary is expected to be draped
through Illinois on Sunday. Additional precip, including snow, is
possible Sunday night into Monday as a stronger wave digs through
the northern Plains. Model differences remain considerable at
this range, but a few ensemble members have accumulating snow with
that system so it will be worth keeping an eye on in the coming
days.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 524 PM CST Tue Nov 16 2021

In the short term, an area of low MVFR ceilings in southern
Illinois is expected to spread northeast this evening. Some
uncertainty with the western extent, though the HRRR does spread
it into KPIA/KSPI. Much of this should be past the terminals by
06Z or so. Another round of lower ceilings will move in from the
northwest ahead of a cold front, arriving at most sites before 12Z
and continuing the balance of the forecast period.

Wind gusts expected to pick up this evening as a warm front
continue to lift north. Maintained the mention of LLWS beginning
around 03Z and lasting til around 09-10Z. Surface winds expected
to shift to the northwest around 13-14Z at KPIA, with the wind
shift passing KCMI around 19-20Z.


&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...Geelhart
SYNOPSIS...Geelhart
SHORT TERM...Erwin
LONG TERM...Erwin
AVIATION...Geelhart



Area Forecast Discussion

National Weather Service Indianapolis IN

 1001 PM EST Tue Nov 16 2021

.Forecast Update...
Issued at 1001 PM EST Tue Nov 16 2021

Surface analysis late this evening shows low pressure in place
over IA/MN and a second area of low pressure over KS. A cold front
connected these areas of low pressure. A warm front associated
with these systems was found over Srn IL and W KY. S-SE surface
flow was in place across Central Indiana ahead of the warm front.

Models showing a nice 850mb LLJ of 40-50knts pushing across Indiana
overnight. The previously mention warm front is expected to push
north across Central Indiana overnight. This will result in rising
temperatures overnight. Also models are suggesting increasing lower
level cloud development with the rising temps and forecast soundings
and time heights suggest lower level saturation. This has yet to
appear within the region as cloud cover for the moment is limited
to high CI streaming ahead of the cold front into the Ohio
Valley. Some lower clouds are present in SRN MO and NRN Arkansas.
Thus will trend toward increasing clouds overnight along with
rising temps. Good mixing providing by the LLJ along with
increasing cloud cover and warm air advection should permit rising
temps overnight.

&&

.Short Term...(This evening through Wednesday night)
Issued at 213 PM EST Tue Nov 16 2021

Quiet weather will continue the rest of the afternoon with upper
ridging across the area. Mainly some high clouds are expected.

During the evening, a warm front will lift northeast across central
Indiana. Lower clouds will accompany the front, making skies mostly
cloudy. Overall moisture will be limited to the lower layers.
However, there will be some weak lift in this layer. Thus, wouldn`t
be surprised to see some sprinkles with it.

Behind the front, temperatures will rise through the 50s. Some of
the stronger winds aloft will mix down, bringing wind gusts over 20
mph.

On Wednesday, strong southerly flow will continue as a cold front
approaches from the northwest. Time/height cross sections continue
to show plentiful low level moisture, so believe there will be
enough clouds for mostly cloudy conditions. Even though there will
be clouds to limit overall mixing, wind gusts of 30 to 35 mph will
be possible at the surface (40kt winds will be less than 2000ft off
the ground).

The cold front will move into the northwest half of the area during
the afternoon as the upper trough to the west approaches. Strong
forcing will occur with isentropic lift, frontogenetical forcing,
and broad forcing with the upper trough working together. Moisture
will be plentiful too with the strong southerly flow. Will thus go
high PoPs across the northwest half by the end of the Wednesday
period, with lower PoPs southeast.

The high PoPs will work their way southeast Wednesday night as the
front moves through. By late Wednesday night, only the southeast
parts of the area should still have any chances for rain.

As for temperatures on Wednesday, warm advection will continue, and
morning readings will already be in the mid and upper 50s. However,
am concerned that the lower clouds will put a damper on things. Will
thus keep highs in the 60s all areas. If more sunshine than expected
develops (most likely southeast, farthest from the front), readings
may get into the 70s. Colder air will flow in Wednesday night, but
precipitation should be gone before any area would get cold enough
for snow.

&&

.Long Term...(Thursday through Tuesday)
Issued at 213 PM EST Tue Nov 16 2021

The long term will initiate with a passage of a cold front early on
Thursday. Some lingering showers on the backside of the front could
bring an isolated chance of precip Thursday, although a strong
gradient along the boundary indicates precip will be mostly ahead of
the front, with katafront like characteristics. A cooler airmass
behind the front will move in for Thursday and Friday, although with
strong CAA, and building surface pressure, skies should begin to
clear. The low aloft will still remain close enough for some
influence in the PGF around central Indiana. The cooler airmass will
steepen near surface lapse rates, aiding in PBL mixing. This is
combination with moderate PGF over the region will lead to breezy
conditions Thursday. Expect sustained winds around 12-15MPH with
gusts upwards of 30MPH. High temperatures Thursday and Friday will
be in the 40s with lows once again below freezing.

Another wave will approach from the northwest, impacting the weekend
weather. Initially, impacts will mainly be on temperature as winds
shift to the SW and push warmer air over the region. Temperatures
should be 10+ degrees warmer on average this weekend than
Thursday/Friday. With the main vertical lift originating from a
zonal jet streak, there is still wide ensemble variance in the
timing of the projected surface based development.  This has lead to
low confidence in precipitation for Sunday. Confidence increases in
precip for Monday, as a deep trough interacts with the low level
wave adding additional forcing over the region. Temperatures for
early next week will be lower as clouds become more abundant, but no
strong airmass change is expected until the middle of next week.

&&

.Aviation...(00Z TAF Issuance)
Issued at 557 PM EST Tue Nov 16 2021

IMPACTS:
- Low level wind shear expected tonight into Wed morning.
- Southerly winds gusty tonight through Wednesday
- Ceilings dropping to MVFR overnight

Discussion:

High clouds as seen on satellite are expected through 05Z. A warm
front will arrive overnight and Cigs are expected to fall to MVFR.
time heights show the arrival of lower level moisture after 06Z
and this persists through the rest of the TAF period. Gusty winds
are expected to become southerly overnight in the wake of the
front...and this may result in some LLWS.

MVFR conditions will continue on Wednesday, and wind gusts will
increase to over 25kt from the south/southwest. Rain chances
increase after 18Z...as the HRRR begins to hint at the arrival of
showers associated with mid level moisture and an approaching cold
front.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

Update...Puma
Short Term...50
Long Term...Updike
Aviation...Puma



Area Forecast Discussion

National Weather Service Marquette MI

 653 PM EST Tue Nov 16 2021

.SHORT TERM...(This evening through Wednesday)
Issued at 346 PM EST TUE NOV 16 2021

Water vapor satellite this afternoon shows an impressively deep and
wrapped up system over Saskatchewan, with MSAS analysis indicating a
983 mb surface low. Water vapor satellite also shows a strong SW-NE
oriented moisture gradient indicative of an upper-level jet
stretching across the Northern Plains. South and east of the upper-
level jet there is a strong LLJ as a response. The RAP indicates a
broad area of isentropic lift over much of the Upper Midwest caused
by WAA associated with this LLJ. However, model soundings show a
thick dry layer in the mid levels, which is why radar shows only
virga if anything at all. Indications are that the column will
continue to saturate as the strongest warm frontal forcing lifts
northward across the Keweenaw and Lake Superior this evening.
Soundings show that because of this dry air, there could be enough
evaporational cooling for there to be a subfreezing layer in the low
levels below the mid-level warm layer, which is why slight chances
of sleet and freezing rain have been maintained with this forecast.
However, given that precip amounts look to be so light, this little
bit of wintry mixed precip - if it happens at all - will not be
impactful.

Tonight, once the precip associated with the deeper forcing ends, it
still looks like there will be a period of drizzle and fog moving
across the U.P. Thankfully temps still look to be safely above
freezing everywhere as broad WAA continues through the night so we
are not looking at any concern for freezing drizzle. Moist upslope
flow off of Lake Michigan onto the higher terrain, combined with
snow melt (where there is still snow on the ground this afternoon)
will likely make for fog as well. Have kept the fog to just "patchy"
wording for simplicity`s sake, but wouldn`t be surprised if it ends
up being widespread and/or locally dense for a time.

The other story tonight will be the potential for gusty SE winds,
mostly in the downslope along the Lake Superior shoreline east from
Ironwood to Copper Harbor and east of Marquette. As usual, the HRRR
has a strong signal (likely too strong in showing 50+ mph winds as
it often does in this type of scenario) but it is nonetheless an
indication that there could be some 25-35 mph SE winds in these
areas this evening. These strong SE winds could also lead to minor
lakeshore flooding down on the Bay of Green Bay. Flooding potential
looks low, but not zero, so have maintained the ongoing Lakeshore
Flood Advisory for Delta County.

Tomorrow, the system`s cold front will move across the area,
bringing with it breezy conditions and temps falling through the
afternoon over the west half. Over the east half, temps will
continue to rise out ahead of the cold front with highs in the mid
40s expected. The Keweenaw looks to get quite windy in the afternoon
with some 30-40 mph WSW gusts likely. There may be a band of lake
effect snow developing on the west half of Lake Superior late in the
day, but the colder air and deeper moisture hold off until after the
end of the short-term period. Elsewhere it will be dry once the
aforementioned drizzle clears out of the eastern U.P. in the morning.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 448 PM EST TUE NOV 16 2021

Below normal temperatures and lake effect snow are expected on
Thursday and Friday with lake effect ending this weekend as ridging
and near or above normal temperatures return. Forecaster confidence
diminishes early next week as the next upper level trough and
associated surface low track across the Great Lakes region. Cold air
advection behind the trough should cool temperatures back below
normal with the lake effect snow machine firing up early next week.

CAA behind Wednesday`s cold front results in a cool and breezy
Thursday with temperatures struggling to warm above freezing,
especially at higher elevations. Lake effect snow develops Wednesday
night for west to perhaps WSW wind belts then LES gradually veers
northwesterly on Thursday into Thursday night. Assuming water
temperatures of 7C yields lake-850 mb delta-Ts between 14-17C at 00Z
Thursday increasing to 16-19C by 00Z Friday. LES should primarily
impact the Copper Country through Thursday morning until winds veer
more northwesterly midday Thursday. NW flow LES continues through
Thursday evening with LES gradually ending from west-to-east
Thursday night into Friday morning.

WAA gets underway Friday afternoon/evening with gusty southerly
winds ahead of the next trough. A weak cool front moves through our
CWA late Saturday without producing any precip. Sunday appears to be
in the doldrums ahead of the next system moving through Sunday night
or Monday morning. Impacts associated with this system depend on a
phasing interaction between northern and southern stream energies
resulting in considerable ensemble spread and a low confidence
forecast. However, confidence is increasing that a substantially
cooler post-frontal airmass will crank up the lake effect snow
machine for Sunday night into Tuesday morning. A surface ridge axis
moves overhead on Tuesday with lake effect diminishing or shifting
to a westerly or southwesterly direction.
&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 641 PM EST TUE NOV 16 2021

Tonight, a patch of mist, drizzle, and low cigs will develop over
the higher terrain of the central U.P. around SAW thanks to
continued SE upslope flow and melting snow. Will likely see
IFR/LIFR cigs the whole night. Had vis lowering briefly to IFR
late tonight at KSAW as drizzle gets going in ernest. With a
chance of showers at CMX had cigs lowering there to MVFR tonight.
Included LLWS at all sites at least through this evening as the
low-level jet moves across the area.

A cold front will move across the area tomorrow morning leading to
winds veering to westerly and bringing in drier air which will mix
out those lower cigs at SAW and CMX. Therefore, TAFs at SAW and
CMX end with a period of VFR conditions.

Expect IWD to stay mostly VFR through the period.
&&

.MARINE..

Not much change to the going forecast. Gale Warning continues for
the north central and east this evening. Still looking at SSE gales
to around 40 kts with a brief period late evening when a few gusts
up to 45 kts will be possible. On the west half, winds will remain
below gale strength but still be strong at right around 30 kts. For
tomorrow, after a cold front pushes across the lake, it still looks
like a WSW gale to 40 kts on the west half and north central. Have
upgraded the Gale Watch for the west half to a Gale Warning and
extended it just a couple hours into Thursday morning. After that,
with cold air in place, westerly winds will remain around 30 kts
across the lake on Thursday, but right now it looks like any gale
force winds will be intermittent and low-end enough that a Gale
Watch is not needed for Thursday at this time.

Winds will subside below 20 kts from west to east across the lake
Thursday night into Friday morning as a high pressure ridge moves in
from the west. That will be a short-lived reprieve as stiff
southerly winds around 25-30 kts will develop for Friday night and
Saturday. A few gale force gusts will be possible with this system
as well, but at the moment this system looks weaker than the one
that will be affecting the lake tonight into tomorrow. Winds will
subside below 20 kts Saturday night and remain light on Sunday.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
  Lakeshore Flood Advisory until 4 AM EST Wednesday for MIZ013.

Lake Superior...
  Gale Warning until 4 AM EST Wednesday for LSZ244-245-249>251-
     264>267.

  Gale Warning from noon EST /11 AM CST/ Wednesday to 7 AM EST /6
     AM CST/ Thursday for LSZ162-240>244-263-264.

Lake Michigan...
None.
&&

$$

SHORT TERM...RJC
LONG TERM...EK
AVIATION...Voss
MARINE...RJC