Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/02/20

Area Forecast Discussion

National Weather Service Bismarck ND

 948 PM CST Wed Jan 1 2020

.UPDATE...
Issued at 9 PM CST Wed Jan 1 2020

No significant change with this update. Rain has for the most part
transitioned to all snow across the west and south central per
surface observations through 0345 UTC.

UPDATE Issued at 611 PM CST Wed Jan 1 2020

Light rain across northeast Montana through western and south
central North Dakota with the cold front as of 00 UTC will begin
to transition to light snow over the next 2-3 hours as surface
temperatures continue to cool. A few tenths of an inch of slushy
snow are possible. Otherwise, widespread stratus across
Saskatchewan and Manitoba on GOESEast imagery will continue to
spread south across the area overnight.

&&

.SHORT TERM...(This evening through Thursday)
Issued at 345 PM CST Wed Jan 1 2020

Upper level low sits over central Manitoba this afternoon with
general longwave troughing extending south into the Northern Plains.
Numerous pieces of energy are rounding the base of the upper low,
streaming across the local area. This has led to widely
scattered, light precipitation from western into southeast North
Dakota this afternoon. At the surface, low pressure sits over
south central Manitoba, with a warm front extending south through
the Devils Lake Basin and James River Valley, and a cold front
extending south and west into northwest North Dakota. Despite the
analyzed location of the warm front, the warmer air has yet to be
felt across the lower terrain of the eastern halves of LaMoure and
Dickey Counties. This has resulted in a period of light freezing
rain there. Surfaces may remain slick through the afternoon, and
possibly into the evening.

Back to the west, most of the precipitation has been confined south
of the cold front, and has been mostly rain. Any precipitation that
occurs behind the cold front could be a rain/snow mix or all snow,
as was observed at Williston earlier this afternoon. The cold front
will continue to sag south across the state this evening into
tonight. The general thinking is that not much precipitation will
fall behind the cold front as it is bringing in a drier, more
subsident air mass. There could still be some light snow across
the southern two thirds of our forecast area tonight, but little
to no accumulation is expected.

A low level baroclinic zone is forecast to set up near the ND/MT
border by Thursday morning ahead of the next approaching wave. There
is a slight chance of light snow or flurries there Thursday morning
and afternoon in the presence of weak warm air advection/isentropic
ascent. Otherwise, expect quiet and cooler weather for Thursday.

By Thursday afternoon, a shortwave trough is forecast to be located
over central Montana. Extended runs of the HRRR and RAP are a
little more progressive with this feature and bring accumulating
snow into northwest North Dakota as early as mid afternoon. All
other guidance keeps the more persistent snow farther west until
after sunset.

.LONG TERM...(Thursday night through Wednesday)
Issued at 345 PM CST Wed Jan 1 2020

A shortwave trough will cross the area from northwest to southeast
Thursday night through Friday morning. Forcing for ascent may be
aided by a left exit region of a jet streak moving off the Northern
Rockies. Generally expecting 1 to 2 inches of snow accumulation from
northwest to south central North Dakota, with lighter amounts
elsewhere. But as was the case yesterday, there are still hints
of enhanced snow rate potential in model guidance due to the
presence of frontogenesis (mesoscale banding) and EPV near zero
(slantwise convection).

Behind the shortwave, ridging will build over the region late Friday
into Saturday. By Saturday afternoon, western and central North
Dakota are forecast to be under the warm sector of a strengthening
clipper system. This setup should promote seasonally strong boundary
layer mixing. Highs are forecast rise well above freezing across the
western half of the state, and near 50 degrees is possible in the
southwest.

The aforementioned clipper will move through the region late
Saturday into Sunday. Despite sufficient forcing, the atmosphere
appears to be too dry for widespread precipitation. The main concern
with this clipper will be winds. Models currently suggest 40-50 kts
in the 900-800 mb layer with a period of decent low level lapse
rates and strong cold air advection/pressure rises. Not confident
these winds will fully mix down to the surface, but at least
advisory criteria winds certainly look possible.

Another clipper is forecast to move through on Monday. Winds will
be weaker with this clipper, and there could be some light
precipitation. Better chances for accumulating snow look to arrive
mid week as we stay in an active pattern. Temperatures will start
out near normal next week, but cold Arctic air may be on the way
by the following weekend.

&&

.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 946 PM CST Wed Jan 1 2020

MVFR/IFR conditions in light snow at times mixed with rain
southwest and south central tonight. MVFR/IFR stratus will
continue to spread from north to south across western and central
North Dakota overnight and remain on Thursday. Light snow will
enter western North Dakota late Thursday afternoon and spread east
into the evening and overnight. IFR conditions are possible.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...PA
SHORT TERM...Hollan
LONG TERM...Hollan
AVIATION...PA



Area Forecast Discussion

National Weather Service Caribou ME

 1036 PM EST Wed Jan 1 2020

.SYNOPSIS...
High pressure builds over the area late tonight through
Thursday and then slides offshore as low pressure tracks across
southern Quebec Friday, then into the Canadian Maritimes Friday
night. Another low tracks from the Mid-Atlantic States Saturday
morning to the eastern coast of Nova Scotia by Sunday evening.

&&

.NEAR TERM /THROUGH THURSDAY/...
1035 PM Update: Plenty of clouds still around w/some open spots
in the last satl imagery. The latest RAP guidance along w/the
12Z NBM keeps clouds around mainly across the northern and
western areas w/the Penobscot Valley and Downeast starting to
clear later tonight. Current overnight temps look in good shape
and decided to hold w/the daycrew`s assessment. NW flow has set
up w/some CAA. This flow off the open St. Lawrence will lead to
some streamer/snow showers overnight, mainly affecting the
northern border. Kept 20% chance going for that area.

Previous Discussion...
Upper low will continue to wrap up into the Gulf of St.
Lawrence this evening and overnight. With NW winds entering
behind the circulation, approaching ridging will enhance these
winds aloft for some cold air advection overnight. Daytime
mixing will be gone, with a mostly stable layer at the surface.
Thus, can expect any gusts to be less than daytime values
despite the 30 kts present at 925/850mb. The ridge crests during
the day Thursday, with much of the forecast area seeing a drier
day. Snow showers will be limited to upslope portions of higher
terrain along the western Quebec border.

Winds will become calm during the late afternoon hours Thursday
as direction changes W to SW. Advection of moist air ahead of
some snow showers to the west begins Thursday evening.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
The surface and upper ridge crests over the region Thursday
night and a weak warm front will lift northward across the area
during the night into early Friday morning. This front is
associated with a dry northern stream low in Canada and little
or no precipitation is forecast...outside of a dusting in
northern Aroostook County. The entire area will be in the warm
sector Friday with highs in the upper 30s to lower 40s. These
reading will be some 10 to 15 degrees above normal. A
disorganized swath of southern stream moisture will pass well to
the south on Friday and Friday is forecast to be dry. The moist
and warm air mass on Friday night presents a good opportunity
for dense fog. Dew points will be near the freezing mark and
overnight lows will be some 20F above normal. Will not include
in the forecast just yet as location and timing remain in
question with a cold frontal passage later in the night. The
front will cross the forecast area, but won`t bring much cooler
air on Saturday as highs will again be way above normal. The
front will stall south of the area and a rich supply of southern
stream moisture will ride up the boundary with increasing
cloudiness as the day progresses. Precip may break out in the
southern half of the area in the afternoon...mostly in the form
of rain initially, but wet bulbing and cold air advection will
cause a changeover to snow later in the afternoon. The forecast
for Saturday into Saturday remains in doubt as guidance is
having a hard time with the placement of cyclogenesis as a
closed upper low dives southward from the upper Mississippi
Valley towards the southeastern US. Am favoring the 01/12Z ECMWF
scenario of a low forming in the Ohio River valley and then
redeveloping along the southern New England coast. The 01/12Z
GFS is further north and 01/12Z GEMS is much further south.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
Following the ECMWF solution, low pressure deepening rapidly off
the southern New England coast along a track south of Nova
Scotia Saturday night into Sunday. Colder air is drawn into the
system and P-type should be mostly snow except towards the
coast. Depending on the timing of the colder low level air and
deepening of the low, some mixed precip can`t be ruled out from
Bangor and Downeast before it all changes to snow. Our current
forecast track would also minimize accumulations towards the
Saint John River valley. For Sunday night into Monday, cold air
advection and high pressure are expected. By Monday night, light
winds and clearing skies could create an opportunity for
radiational cooling to produce lows well under guidance. A weak
clipper system appears to be in the cards for Tuesday with
little or no precip, but some cloudiness. PoPs increase again
Tuesday night into Wednesday night as another complicated system
moves towards the area. The 12Z suite of models offer solutions
ranging from a complete miss to a warm rain event. Once again,
the ECMWF offered a middle ground...phasing northern and
southern stream systems and generating a coastal low. Our
current forecast calls for a mostly snow event based on
composite surface and upper air temps, but confidence is not
high at this point.

&&

.AVIATION /04Z THURSDAY THROUGH MONDAY/...
NEAR TERM: Lingering snow showers will dissipate later this
evening. Vis has been largely unaffected, but some MVFR vis
cannot be ruled out early this evening. Clgs will begin MVFR in
lower clouds across northern terminals, with a trend to VFR
overnight.

SHORT TERM:
Thursday night...MVFR cigs will arrive north of HUL with a brief
period of IFR vis in snow for CAR and FVE. VFR elsewhere.

Friday...MVFR cigs will start north of HUL

Friday night...risk of LIFR fog until later in the night

Saturday...VFR once morning low clouds/stratus are swept out

Saturday night and Sunday...IFR in snow for sites south of HUL,
VFR north

Sunday night and Monday...VFR

&&

.MARINE...
NEAR TERM: SCA conditions will continue to around noontime
Thursday with winds gusting to around 30 kt and seas 4 to 7
feet. Winds will slacken Thursday evening, with seas falling to
3 to 5 feet.

SHORT TERM: Expect a strong SCA or lower end gale for Saturday
night into Sunday. Another SCA is possible by Tuesday night into
Wednesday.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...Small Craft Advisory until 1 PM EST Thursday for ANZ050>052.

&&

$$

Near Term...Hewitt




Area Forecast Discussion

National Weather Service State College PA

 1035 PM EST Wed Jan 1 2020

.SYNOPSIS...
It will remain dry and turn milder on Thursday as a southerly
air flow develops across the Commonwealth. Another rainy period
looks to be in store for Thursday night into Saturday, before
it turns colder again later in the weekend.

&&

.NEAR TERM /UNTIL 8 AM THURSDAY MORNING/...
Clearness continues. A few high clouds will sneak down from the
north, but it appears that the low clouds that the NAM and
cousins are generating in the light upslope flow are as of yet
figments. HRRR and RAP do not saturate the lower levels but do
show a slight/moderate increase in RH through the night. Temps
could be at their lowest across the west and central, but will
likely fall a few more degs in the east/lower elevs where there
is little/no wind.

&&

.SHORT TERM /8 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
On Thursday, morning sunshine should fade behind thickening
afternoon cloudiness, as moisture begins to spread over the
region on the heels of a strengthening SW flow aloft. It still
appears that any light rain will hold off until well after dark.

It will turn much milder Thursday, as warm advection and at
least early insolation combine to push readings into the 40s.
Parts of the Lower Susquehanna Valley could touch 50 degrees.

&&

.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
Rain moves in on Thursday evening and 100 PoPs are on order for
everyone by the end of the night. Did decrease PoPs a little
early on, but warm advection has a way of moving along a little
faster than the mdls sometimes portray. Likely we will see virga
for a few hours before the precip works down. P-type issues look
to be nil, even though the onset is during the middle/end of the
night. Temps should stay above freezing and top-down makes it
all liquid by the time it gets to the sfc.

The mild, overcast and damp weather will continue through late
Friday into Saturday. Occasional light rain/drizzle is possible
and this is associated with the southern surface low lifting
northeast into the region from the Mid Mississippi Valley.

Medium range guidance suggests there may be enough cold air on
the back side of exiting surface low for a period of snow
Saturday night, primarily over the Allegheny Plateau.
The transition period will be Saturday night. Sunday may be a
very short break in precip, but a brief pd of LES is likely.

Sunday night into Monday, an Alberta Clipper will attempt to
bring some -SN in from the NW. But, the best PoPs are over the
NW, and almost nil chc over the SE. Ridging back again for
Monday. Tuesday is a split between major med range guid. The EC
does continue to bring some SN to the area due to a deepening
low under a tilting upper trough, but the GFS is more to the
east with these features. W/NW flow Wed is the case from all the
med range guid as the upper trough gets overhead. This should
make some LES. Next Thurs looks pretty dry, but the highly
progressive pattern may allow no rest in the train of mainly-
warm storms.

&&

.AVIATION /03Z THURSDAY THROUGH MONDAY/...
Conditions will relax this forecast period with high pressure
bringing in clear skies and diminishing winds. The general trend
for all sites will be for light winds and clear skies overnight.
Winds will pick up gradually tomorrow during the late morning
then diminish again during the early evening. Clear skies will
give way to a lowering cloud deck after 21Z/02JAN in advance of
an approaching system from the southwest. Conditions will
remain VFR through Thursday evening.

.Outlook...

Thu night-Fri...Restrictions developing in lower ceilings,
rain, and fog.

Sat-Sun...Restrictions likely at KBFD and KJST in snow showers,
with mostly VFR elsewhere.

Mon...Some restrictions could continue into Monday in light
snow/snow showers, especially KJST and KBFD.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$
SYNOPSIS...Jurewicz/Dangelo
NEAR TERM...Jurewicz/Dangelo
SHORT TERM...Jurewicz
LONG TERM...Dangelo/Fitzgerald/Ceru
AVIATION...Jurewicz/Tyburski



Area Forecast Discussion

National Weather Service Grand Forks ND

 707 PM CST Wed Jan 1 2020

.UPDATE...
Issued at 707 PM CST Wed Jan 1 2020

Allowed Winter Weather Advisory to expire as scheduled and
replaced with Special Weather Statement as there are still a few
lingering pockets of light freezing rain/sleet moving into
northwest MN. Coverage is still greatly diminished from earlier
today, and we should see a diminishing trend continue through the
evening as well and tendency for activity to become mainly snow
if it lingers past midnight when better CAA arrives across much of
our CWA.

UPDATE Issued at 614 PM CST Wed Jan 1 2020

Organized cluster or freezing rain/sleet has transitioned east
into deeper cold, however additional pockets of light showers have
developed into southeast ND with light returns lighter further
west and north. RAP profiles show warm layer lingering ahead of
cold front and surface analysis indicates this is just now
entering north central ND. Until better CAA arrives this evening
we have a window where any light precip that develops along or
west of the RRV could fall as more of a mix and additional light
icing can`t be ruled out. Coverage is decreasing though as better
forcing and WAA transitions east and south, so duration/coverage
of measurable may remain isolated. Still, impacts associated with
additional light icing on untreated surfaces can`t be ruled out.
For ND I went ahead and issued SPS and will monitor conditions
where advisory is still in effect for another hour in MN.

&&

.SHORT TERM...(This evening through Thursday night)
Issued at 225 PM CST Wed Jan 1 2020

Continuing to observe precipitation as it moves to the east this
afternoon. A mix of freezing rain, sleet, and light snow is
pushing through the Red River valley, with the snow line situated
just east of the Valley, along and east of a line that extends
from Crookston to Mahnomen.

Heading into tonight, look for continued precipitation chances
with a gradual change over to all snow later this evening. Winds
will shift and become westerly and eventually northwesterly as a
500 mb shortwave moves across the area. Temperatures remain above
normal for tonight into Thursday with lows in the teens tonight
and highs climbing into the 20s Thursday with persistent cloud
cover.

.LONG TERM...(Friday through Wednesday)
Issued at 359 PM CST Wed Jan 1 2020

As zonal flow aloft sets up this weekend through the first half of
next week several weak waves will move across the area bringing
light precip possibilities. The first is Thursday night into Friday
morning with ensemble QPF suggesting under 0.05" with the entire
column below freezing just expecting an all snowfall event with the
highest amounts under an inch in the southern valley.
Frontogenetical forcing with this system appears transient at best
meaning short residence time and not sustained as the wave slides
across the region. Another wave is expected to brush NW MN Sunday
with light snowfall potential. Thereafter timing of the weak
impulses remain undefined and continue to present little confidence
of when any low impact event may occur.

Generally temps will be in the 20s for highs this weekend and cool
into the teens for the start of the work week and beyond. Lows in
the single digits and teens can be expected and will, per usual,
depend on cloud cover and winds with the deep snowpack present
across the region. These values are a bit above normal to at normal
for the first half of January.

&&

.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 614 PM CST Wed Jan 1 2020

Pockets of freezing rain and sleet continue to transition over
parts of eastern ND into northwest MN. In MN trend is towards this
becoming mainly snow further east, however until a cold front
drops south this evening potential for aviation impacts this there
through the evening. Ceilings are highly variable ranging from
brief LIFR with most locations MVFR or VFR currently. Our
guidance has been way to pessimistic the last few days on
prevailing IFR conditions (or worse) and based on current trends
upstream I am inclined to think this is still the case. I trended
our TAFs a little more optimistically towards MVFR prevailing. I
will monitor trends this evening to see how this pattern evolves.
Low confidence overall especially after the first 6 hours of the
TAF period.


&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
&&

$$

UPDATE...DJR
SHORT TERM...Lynch
LONG TERM...JK
AVIATION...DJR




Area Forecast Discussion

National Weather Service Marquette MI

 643 PM EST Wed Jan 1 2020

.SHORT TERM...(This evening through Thursday)
Issued at 412 PM EST WED JAN 1 2020

WV imagery and RAP analysis indicated a broad low amplitude
mid/upper level trough the the Plains with several weak embedded
shortwaves. One was located over northwest WI with another over the
eastern Dakotas. At the surface, southerly winds were increasing
through the Upper Mississippi Valley and western Great Lakes between
a trough from southern Manitoba into the eastern Dakotas and a ridge
from the southeast CONUS to the eastern Great Lakes. IR and vis loop
showed increasing mid/high clouds into the area as WAA increases.

Tonight into Thursday, expect clouds to thicken as the Dakotas
shrtwv and isentropic lift increases. Even though the relatively dry
low levels will minimize potential for any signficant pcpn, some
light snow showers or freezing drizzle may be possible, especially
toward daybreak. Otherwise, expect mild conditions with temps steady
or slowly rising tonight from the low to mid 20s to around 30 or the
low 30s early Thursday. After the pcpn chances in the morning, temps
should climb into the mid to upper 30s in the afternoon.

.LONG TERM...(Thursday night through Wednesday)
Issued at 418 PM EST WED JAN 1 2020

The mid-latitudes will consist of a fairly progressive pattern
through the next week as Upper Michigan will see multiple troughs
and ridges traverse across the Great Lakes. Two shortwaves will be
in the vicinity Thursday night as a quick wave passes Thursday
evening with another right behind it passes to the north of Lake
Superior Thursday night. Moisture is limited, but this wave may kick
off some -SHSN or perhaps -DZ/-FZDZ if saturation is deep enough but
outside of the DGZ across the west. A ridge of high pressure builds
into the Plains late Friday into Saturday as models suggest a
shortwave to eject from the Southern Plains towards New England on
Saturday afternoon. The next chance for precipitation across Upper
Michigan then comes with a clipper shortwave passing on Sunday
afternoon into Monday. Slight ridging returns Tuesday as another
clipper wave approaches Wednesday.

Thursday night, as a shortwave exits to the east and another wave
passes to the north of Lake Superior, winds back from SW to W and
then W to NW. At the same time, 850mb temps fall to -8 to -10C;
however, moisture is generally lacking so accumulations across the
west and central portions of the UP will remain limited. If any
precipitation falls, it will likely remain as BR or perhaps -DZ/-
FZDZ. If a bit more moisture is available, could start to see some -
SHSN as well. Otherwise, could also see some slippery conditions on
untreated surfaces with Thursday`s highs into the 30s and then lows
falling blo freezing on Thursday night...in addition to slight
chances of -FZDZ . Moisture will remain limited, but these chances
will remain in the west to northwest wind belts through Saturday
morning.

A clipper shortwave will pass to the southwest on Saturday as a
shortwave ejects from the Texas Panhandle and lifts north through
the Ohio River Valley. Which should keep the UP generally dry, but
cloudy as usual, until a clipper shortwave passes Sunday. PoPs
increase through the day, becoming likely across the west and
lingering into Wednesday as 850 temps remain in the teens blo
zero...with the exception of the EC.
&&

.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 632 PM EST WED JAN 1 2020

An upper disturbance approaching from the west will likely result
in ceilings falling to MVFR overnight into Thursday. Some light
precipitation, mainly as snow or light freezing drizzle, may
develop Thursday morning. However, the probability was low enough
to leave out mention in the KIWD and KSAW TAFs. Did include
mention of snow at KCMX as winds shift west and lake effect snow
develops Thu afternoon. &&

.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 412 PM EST WED JAN 1 2020

Persistent southwest flow lingers across the lake through mid-day
Thursday at speeds of 20 to 25 knots, strongest across western parts
of the lake ahead of a weak cold front progged to track across the
lake Thursday evening. Behind the front, winds turn west 20 to 25
knots Thursday night, and then northwest 10 to 20 knots Friday. Wind
then remain below 25 knots through Saturday. A clipper system
tracking southeast across the Upper Great Lake Sunday through Monday
will impact winds across the lake; however, the track and timing of
this system remain uncertain so confidence in the wind forecast that
far out is low.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&

$$

SHORT TERM...JLB
LONG TERM...JAW
AVIATION...Voss
MARINE...JLB