Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/24/18

Area Forecast Discussion

National Weather Service Aberdeen SD

 904 PM CST Tue Jan 23 2018

.UPDATE...
Issued at 903 PM CST Tue Jan 23 2018

Have slowed down the onset of fog, and shifted it farther east, given
the slow movement of the upstream low clouds and fog and model
guidance. Otherwise, few additional changes were needed to the
ongoing forecast.

&&

.SHORT TERM...(This Evening through Wednesday Afternoon)
Issued at 317 PM CST Tue Jan 23 2018

The forecast challenge tonight into Wednesday will be whether or not
fog and/or low stratus forms over the CWA for a third consecutive
night, and its impacts on temperature.

Currently, temperatures are holding in the 20s across the eastern
third of the CWA, where low stratus clouds and patches of fog
persist. The sun is shining through some high clouds across the
western two-thirds of the CWA, where temperatures are warming into
the 30s and 40s.

The high clouds are associated with an upper level wave working
through the region. Once that wave/cloudiness moves southeast of the
region, another clear sky night on light (albeit westerly component)
winds will be in play. And, there will probably be adequate low
level moisture still around tonight in the nocturnal boundary layer
to aide in more fog or low stratus development, especially within
and between the Missouri and James River valleys and up on the
Prairie Coteau. East of the Coteau may end up being more stratus
than fog. Since there is support from the RAP in BUFKIT, along with
several other numerical guidance data sets, opted to stick with fog
mention in the weather grids for tonight into the first half of the
day Wednesday. Similar to last night, temperatures should not drop
off much more than perhaps 5 to 10 degrees underneath cloudy areas
tonight. Clear areas may be able to drop closer to 15 to 20 degrees
before stabilizing in fog/stratus environment, with a slow
temperature rebound expected on Wednesday, if fog/stratus tonight
pans out.

.LONG TERM...(Wednesday Evening through Tuesday)
Issued at 317 PM CST Tue Jan 23 2018

When the period opens Wednesday night, a large upper level ridge of
high pressure is beginning to build into the region. By Friday
morning, the upper ridge has shifted east and is being replaced by a
large/broad upper level trough of low pressure. By Sunday morning,
we`re right back where we started when the period opened, with
another upper level ridge trying to build into the region from the
west. However, the 12Z GSM deterministic solutions all agree today
on this next upper level ridge being suppressed while it works into
the middle of the country and for a brief period heading into day 7,
there could actually be nearly zonal flow over the region.

In this continued progressive pattern of ridge/trof/nearly zonal
flow, the forecast is still basically a dry forecast. The warming
trend still shows up in the deterministic low level thermal progs as
well as ensemble guidance through Friday. The onset of the broad
longwave upper trof still progs a cold frontal passage through the
CWA late in the week, with temperatures cooling back down to near,
or perhaps just below, climo normal for the weekend. The suppressed
ridge/nearly zonal flow set-up for early next week potentially
ushers a quick turn around back into some well above climo normal
temperatures by Tuesday.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening)
Issued at 534 PM CST Tue Jan 23 2018

Confidence is growing that ABR will join ATY in the IFR category
by around 06Z tonight as additional low level moisture sinks south
from ND. MBG will be on the western edge of this low cloud/fog
field, and am less confident that it will occur. Took out much of
the fog potential at PIR for now, but it may be able to slip in
around 09Z Wednesday. Winds should be around or below 10kts
through the period.


&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&

$$

UPDATE...KF
SHORT TERM...Dorn
LONG TERM...Dorn
AVIATION...KF




Area Forecast Discussion

National Weather Service La Crosse WI

 533 PM CST Tue Jan 23 2018

.SHORT TERM...(This evening through Wednesday)
Issued at 316 PM CST Tue Jan 23 2018

At 2 PM, there was an area of sunny skies from northeast
Minnesota south into north-central Iowa.  A bit of this clearing is
creeping into parts of Dodge County in southeast Minnesota.
Temperatures ranged from the teens to mid-20s.

The 23.12z models are in agreement that a short wave trough will
move southeast through Iowa and Missouri tonight. With the air mass
dry across the region, most of the models are in agreement that we
will remain dry.  The one exception is the RAP which tries to
generate some flurries south of Interstate 90.  For the time being,
just stayed with the dry forecast.

On Wednesday, the models show that another short wave trough will
move southeast across northern Minnesota and Wisconsin.  Like its
predecessor, the air mass looks too dry for precipitation.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 316 PM CST Tue Jan 23 2018

The main story for the extended forecast is warmer temperatures,
especially on Friday.

Upper level ridging and southerly flow build into the region
Thursday into Friday resulting in much warmer temperatures. 925 mb
temperatures are expected to warm to +3 C to +6 C during this
timeframe.  Plan on high temperatures on Friday ranging from the
lower and mid 40s across portions of north-central Wisconsin to
around 50 over far southwest Wisconsin and portions of northeast
Iowa. A weak cold front slides through the region Friday night into
Saturday cooling highs back into the 30s to around 40. Another surge
of warm air is possible on Tuesday ahead of the next system.
There are signals way out in the extended that temperatures could
cool significantly going into the first week of February but it`s
a little early to nail down specifics.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 533 PM CST Tue Jan 23 2018

Rather difficult ceiling forecast for this set of TAFs. Satellite
currently showing a break in the clouds over southeast Minnesota
into central Iowa that is working slowly east. This has allowed
the skies to clear at KRST but additional low clouds west of this
clearing with MVFR ceilings are also working slowly east. Looking
at forecast soundings from the 23.18Z NAM would expect the lower
clouds from the west to spread back in with this moisture then
getting trapped beneath the inversion and remaining through
Wednesday. The clearing could also allow some fog to form
overnight with light winds and lots of low level moisture in place
from the recent precipitation. For KRST, plan to show VFR
conditions this evening with some fog then forming overnight and
the lower clouds moving back in for a return to MVFR for the
overnight through Wednesday. For KLSE, expecting the current MVFR
ceiling to move out by mid evening with VFR overnight before the
lower clouds and MVFR ceilings move back in during Wednesday
morning.

&&

.HYDROLOGY...Through Saturday
Issued at 316 PM CST Tue Jan 23 2018

Elevated river levels will continue to recede across portions of
northeast Iowa, southeast Minnesota, and southwest Wisconsin over
the next few days. Be alert for possible ice jamming over the next
few days and localized high water or minor flooding. More ice
jams are possible on Friday as temperatures surge into the 40s to
possible lower 50s.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&

$$

SHORT TERM...Boyne
LONG TERM...Wetenkamp
AVIATION...04
HYDROLOGY...Wetenkamp



Area Forecast Discussion

National Weather Service Gray ME

 1029 PM EST Tue Jan 23 2018

.SYNOPSIS...
Temperatures have struggled upward all day...finally reaching
near freezing. After widespread freezing rain of one to two
tenths...precipitation is coming to an end from west to east
late this afternoon and early this evening. Any remaining
showers will transition to snow in the mountains...while to the
south dries out. Temperatures will remain fairly steady
this evening...climbing with the cold front around midnight
before slowly falling towards sunrise. Near normal temperatures
are expected Wednesday...with much colder overnight temperatures
Wednesday night. High pressure builds in for the remainder of
the week.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
1030 PM Update...Have adjusted temperatures, sky cover, and
winds a little bit for the overnight hours. However, no big
changes have been made. The last band of rain is quickly moving
eastward and out of the area. It should clear the mid coast
around midnight...maybe a bit after. Rapid clearing is taking
place behind the batch of rain (except across far western and
northern zones). This may lead to some radiational fog for a
time before winds increase. Slippery conditions are also
expected on untreated surfaces overnight, especially where it
clears and and stays calm.

805 PM Update...Have allowed the remaining winter weather
advisories expire on time at 8 pm. Most locations have risen to
between 32 and 33 degrees at this time. However, we do expect
many slippery areas to continue overnight - especially in areas
that clear out after midnight and the winds stay calm. This
could lead to a quick refreezing of some surfaces - especially
secondary roads, parking lots, and sidewalks. In the meantime we
do have one more band of mostly rain to move through.
This will move through quickly - likely lasting around 1 hour at
any given location through 03-04z and could be accompanied by an
isolated rumble of thunder. Winds may pick up somewhat with or
immediately behind this band which could cause some more
branches to fall and cause power outages.

610 PM Update...Have updated mainly PoPs for the next 3 hours or
so as a strong short wave trough will swing through with a
relatively short-lived band of showers. This can currently be
seen near the NY/VT border. The latest run of the HRRR has a
pretty decent handle on it, so updated the PoPs to reflect the
HRRR for the most part. Most locations are at or just above
freezing at this time, so this should mainly be in the form of
rain. However, some spots are still just below freezing
(especially in the advisory area) so some additional minor ice
accretion will be possible until about 03z or so. Thereafter,
a clearing trend is expected. Otherwise, have cancelled the wind
advisory for the mid coast, as 40 kt gusts are not foreseen at
this point.

5 PM Update...Have extended winter weather advisories until 8 pm
where temperatures are still around or just below freezing. This
includes interior portions of our Maine zones and Carrol County
NH. Have cancelled Coos County as most areas are now above
freezing. In any event, the precipitation will come to an end
over the next couple of hours, with power outages possible
through that time.

Previously...

Back edge of the precip has reached the CT River Valley this
hour...and will continue to pull Ewd into the late
afternoon/early evening. WAA and latent heating has pulled
surface temps up to just about freezing in most locations. There
are pockets...especially across the interior of Wrn ME...that
remain below freezing and will continue to see occasional
freezing rain into the early evening. For that reason the winter
wx advisories there remain in place. Across Srn NH and coastal
Wrn ME I have allowed those advisories to expire.

Where the warm front has made it onshore around Midcoast ME
there remains a threat for strong Sly wind gusts. So far RKD has
been fairly benign winds...but just offshore at MISM1 wind gusts
above 40 kts have been observed. I will keep the wind advisory
in effect for this threat.

Temps should remain fairly steady into the evening ahead of the
approaching cold front...back across central NY. The upper level
front is quickly moving E...with dry slot bringing some clearing
to far Wrn zones before sunset. With the approach of the
front...deeper mixing will help overturn the low level cold and
temps should rise to their daily max around the 06z time frame.
Temps slowly fall after that...with strongest CAA delaying until
Wed.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
Wly CAA flow will dominate Wed and Wed night. Temps are not
expected to rise too much from morning readings Wed as the
colder air moves in. Winds may gust as high as 30 knots at
times in the afternoon. I would not be surprised to see this
lead to a few scattered outages in places where ice remains
stuck to tree limbs. Temps continue to fall overnight...but
gradient winds will keep readings closer to model raw 2 m temps
than cooler MOS values. Upslope snow showers will continue thru
the day and into the overnight with some light accumulations in
the higher terrain.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
The deterministic model solutions remain in decent agreement on
the long wave pattern through the middle of next week. The
pattern will remain progressive and begins to amplify with time.
A steady progression of troughs and ridges across the forecast
area will result in several sharp swings in temperature between
well below and well above normal readings as we see a parade of
disturbances cross the forecast area. In the dailies...A shortwave
impulse will deliver a reinforcing shot of cold air to the area
for Thursday and Thursday Night. The cold begins to ease on
Friday as ridging and rising heights arrive. A warm front lifts
north across the area Friday night with a southerly flow and well
above normal temperatures arriving for the weekend. The more
progressive GFS was again discarded as an outlier with the
approaching frontal system in favor of the slower ECMWF/CMC-
Global solutions...which bring the front and steadier band of
precipitation across the forecast area late Saturday Night and
Sunday. If the warmer ECMWF/CMC-Global are correct...then a
multi day period of well above normal temperatures coupled with
one to two inches of rain could cause some hydro issues given
current ice jam situation. Colder air begins to filter into the
area by Monday behind this system along with a return to below
normal temperatures for the start of the new work week.

&&

.AVIATION /04Z WEDNESDAY THROUGH SUNDAY/...
Short Term...Once cold front moves thru the winds become Wly
and will help to dry out the low levels. VFR conditions are
expected to quickly return late tonight. Upslope flow in the
mtns will keep HIE MVFR with VCSH.

Long Term...

Sat Night - Sun...MVFR with areas of IFR in Rain and fog.

&&

.MARINE...
Short Term...Strong SCA conditions are expected thru Wed night.

Long Term...

Thu - Fri...Small Craft conditions are likely outside the bays.

Sat...Small Craft conditions are likely...with gusts approaching
gale outside the bays.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Small Craft Advisory until 9 PM EST Wednesday for ANZ150>154.

&&

$$

NEAR TERM...Ekster
SHORT TERM...Legro
LONG TERM...Schwibs
AVIATION...Legro/Schwibs
MARINE...Legro/Schwibs




AREA FORECAST DISCUSSION...UPDATED

National Weather Service Jackson KY

 954 PM EST Tue Jan 23 2018

.UPDATE...
Issued at 954 PM EST TUE JAN 23 2018

A short wave trough will continue to rotate through the Ohio
Valley through the overnight. Some lighter echoes have developed
across eastern Kentucky over the past hour. Expect isolated to
scattered rain/snow showers to continue into the overnight,
before diminishing towards dawn, as forcing exits to the east and
northeast. Have raised the low temperatures a tad across eastern
Kentucky, as readings will be slower to cool off given the
extensive cloud cover across the area, and lack of much colder air
upstream. Wind gusts have also subsided this evening, as the
pressure gradient gradually relaxes across the region. While a
dusting of snow on elevated surfaces across the higher ridgetops
will be possible through the overnight, given the lagging warmer
ground temperatures, little or no impacts are expected. Updates
have been sent.

UPDATE Issued at 651 PM EST TUE JAN 23 2018

The forecast is on track. Merely freshened up the hourly
temperatures and dew points into this evening based on the latest
trends in observations.

&&

.SHORT TERM...(This evening through Wednesday night)
Issued at 415 PM EST TUE JAN 23 2018

A shortwave trough was moving through the eastern Great Lakes and
OH Valley and into the Appalachians this afternoon while a
shortwave ridge was over parts of the MS Valley with another
shortwave upstream over the Plains. Cumulus and stratocumulus was
well entrenched over the lower OH Valley, MS Valley, and Great
Lakes. Some radar returns are upstream over parts of IN and
central KY where mainly sprinkles or flurries are possibly
occurring.

Short term model guidance such as the HRRR brings a shortwave
trough/500 mb vort max across the region this evening and an
associated surface trough. Cold advection is continuing with the
coldest air with this airmass anticipated late tonight and into
the day on Wednesday as the second upstream shortwave trough moves
through. Moisture is expected to remain at the low levels near
and below 850 mb and low clouds should persist through at least
Wednesday evening. The trough departs to the northeast on
Wednesday night with mid level heights rising across the Southeast
and into the Lower OH Valley and TN Valley regions.

Omega peaks on time height sections this evening and again on
Wednesday morning to early afternoon as the two shortwaves move
through when rain or snow shower or flurry or sprinkle activity
should peak. After early this evening, the atmosphere should be
sufficiently cold enough for either isolated snow showers or
flurries.

With the 850 mb temperatures in the -5C to -10C range and cloud
cover anticipated, below normal temperatures are expected for
highs on Wednesday. Skies should gradually clear on Wednesday
night, but NAM guidance suggests clouds should linger the entire
night. If skies were to remain mostly clear to clear the valleys
in the Cumberland Vally could end up around 20 or the upper teens.

.LONG TERM...(Thursday through Tuesday)
Issued at 257 PM EST TUE JAN 23 2018

The extended will start off with a period of warm and dry weather to
end out the week and into the upcoming weekend. A ridge of high
pressure will prompt south to southwest winds which in turn will
transport warm air off the Gulf of Mexico into the Tennessee and
Ohio valley regions. The next chance of rain for eastern Kentucky
will arrive in the area late Friday night, as a cold front
approaches from the Plains. The trend in the latest model data is
for a faster west to east progression of this weekends weather
system, and the forecast will reflect this. Rain showers should
gradually overspread the area on Saturday, and will be most
widespread from Saturday evening through Sunday evening, as a cold
front moves across the region. The precipitation will taper off
Sunday night, as the front moves further from our area. Temperatures
should fall to the point where some snow will mix with the rain
Sunday night. Flurries and a few snow showers are then expected
across the area from around dawn on Monday through early Monday
morning. Any remaining precipitation should be exiting the area by
late Monday morning. After that, the weather should be dry across
eastern Kentucky through Tuesday.

Temperatures in general should be above normal in the extended.
Daytime highs should be in the 50s Friday through Sunday, with
nightly lows ranging from the mid 30s through the lower 40s Friday
night, and in the lower 40s for Saturday night. These two warm
nights are expected to be sandwiched by two colder nights when
temperatures will be in the upper 20s and lower 30s(Fri night and
Sun night).

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
ISSUED AT 651 PM EST TUE JAN 23 2018

Ceilings will lower to MVFR from west to east through this
evening, as an upper level disturbance moves across the Ohio
Valley. Some light rain/snow showers may be seen at times this
evening; however, expect this activity to remain light enough to
not cause much in the way of visibility restrictions.
Precipitation will taper off later tonight, with MVFR ceilings
likely hanging on through the rest of the period. West winds of
around 10 kts, with a few gusts of 15 to 20 kts at times through
early this evening, will gradually diminish overnight and into
Wednesday.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...GEOGERIAN
SHORT TERM...JP
LONG TERM...AR
AVIATION...GEOGERIAN



Area Forecast Discussion...UPDATED

National Weather Service North Platte NE

 518 PM CST Tue Jan 23 2018

.SHORT TERM...(Today and tonight)
Issued at 332 AM CST Tue Jan 23 2018

A midlevel disturbance across ern WY/wrn SD will move through
wrn/ncntl Neb today. The RAP, HRRR, NAM-nest and ECM suggest
scattered flurries. Consensus model data was the basis for the snow
flurry forecast which places the flurries across northern Neb.
The NAM-nest, the most aggressive model, would drive the flurry
activity south to Interstate 80.

A blend of the HRRR and RAP models plus bias correction produces
highs in the lower to upper 30s. This is about 3 to 5 degrees cooler
than the straight guidance blend. Snow cover and cloud cover are the
driving forces behind the temperature mark down. Also, the h850mb
temperature advection is neutral today and tonight.

Clearing skies should develop tonight with a continuation of
generally light northwest winds. A blend of bias corrected guidance
produces lows mostly in the teens, near 10F in the Platte valleys.

.LONG TERM...(Wednesday through Monday)
Issued at 332 AM CST Tue Jan 23 2018

Generally quiet weather is anticipated through midweek as an upper
ridge progresses from the Rockies to the Plains. Temperatures
moderate into the lower 40s Wednesday with the help of downslope
flow and sunny skies. The heart of the ridge arrives Thursday with
H85 temps pushing 12C, which should translate to highs in the 50s
for parts of the area. Continued the trend of keeping temps below
guidance due to snow cover. A lead shortwave drags a cold front
through the region on Friday, and a follow-up shortwave crosses the
Plains on Sunday. Still expecting dry passages as the systems are
moisture starved and forcing is short-lived. With a real lack of
Arctic air upstream, the cooldown will only result in highs in the
mid/upper 30s and lows in the mid/upper 10s, which is right around
climo norms. The only concern during this period is the potential
for large snow melt through Thursday and refreezing each night as
lows drop into the teens.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 517 PM CST Tue Jan 23 2018

Visual flight rules with northwest winds less than 10kts


&&

.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

SHORT TERM...CDC
LONG TERM...Snively
AVIATION...Power