Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/26/20
Area Forecast Discussion...UPDATED
National Weather Service Duluth MN
547 PM CST Sat Jan 25 2020
.UPDATE...
Issued at 547 PM CST Sat Jan 25 2020
Update for new 00Z Aviation Discussion below.
&&
.SHORT TERM...(This evening through Sunday night)
Issued at 316 PM CST Sat Jan 25 2020
Cloudy skies tonight, with continued chances of light snow over
the higher elevations of northern Iron county. Patchy fog will be
possible tonight, with some chilly temperatures over north-central
Minnesota.
An area of surface low pressure, currently situated over northern
Lake Huron and is nearly vertically stacked through 250 mb,
continues to very slowly translate eastward today. Northerly flow
will continue through tonight in the higher levels of the
atmosphere, keeping cold temperatures in place. While weak flow is
expected near the surface tonight, some lingering chances of
precipitation, mainly in the form of snow, will be possible
through Sunday morning. A moist air mass will remain in place,
which will support ice crystal development aloft within the
dendritic snow growth as well as some patchy fog across the
region. However, a lack of robust forcing will only lead to some
light snow accumulations possible along the Lake Superior snowbelt
region, with up to one inch of snow possible from late this
afternoon through tonight. A wedge of colder air will skim across
our southwestern areas tonight, with lows tonight ranging from
around 10 degrees above zero over the Brainerd Lakes region to the
upper teens and lower to middle 20s to the east.
A secondary shortwave trough will make its way across the Dakotas
late tonight and through the day Sunday. We are not expecting any
precipitation from this shortwave in our region, but it will help
to keep cloudy skies in place for Sunday and Sunday night. The
NAM and RAP model soundings both indicate drier air developing in
the ice bearing layer aloft, leading to the potential for freezing
drizzle over Iron county Sunday. Very little impacts from the
icing are expected due to little QPF available. Highs Sunday will
warm into the upper 20s and lower 30s. Sunday night lows will fall
to the middle teens north to the lower 20s south.
.LONG TERM...(Monday through Saturday)
Issued at 316 PM CST Sat Jan 25 2020
A messy upper air pattern over the area through much of the
upcoming work week will make it difficult to pin down specific
times and locations for snow chances, and confidence is not very
high. We have an upper level low over the northeast east coast,
and a weak but long trough over the west coast, and several
shortwaves moving through the west-northwest upper level flow
between the two more coherent systems on the coasts. These
shortwaves bring small chances for precipitation to the area
Tuesday night through Thursday night, with above normal
temperatures through the period. The west coast trough axis moves
to affect the Northland late in the week, bringing increasing
chances for precipitation to the area beginning on Thursday,
continuing through Friday and Friday night. Models are not yet in
agreement on how this feature moves across the area, with some
split flow solutions, and while most of the follow it with a
shortwave that moves through the northern stream flow, some keep
it too far north to affect us, and others bring more precipitation
chances for Saturday. Temperatures warm into Saturday, but the
pattern may bring us some colder weather early the following week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 547 PM CST Sat Jan 25 2020
Stagnant low pressure over near Sault Ste. Marie will loiter over
the region tonight and is forecast to move eastward out of the
region on Sunday. Look for MVFR/IFR ceilings to be the norm
through the forecast period, with some sites dipping into LIFR
CIGS overnight. Think we`ll see areas of fog develop overnight and
have a mention of IFR visibility at BRD overnight through late
Sunday morning. A few snow showers may affect DLH and HYR, though
flight categories will likely be driven by the ceilings.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 22 30 21 28 / 10 10 0 0
INL 15 30 16 25 / 0 0 0 0
BRD 10 27 18 28 / 0 0 0 0
HYR 24 32 24 32 / 10 10 10 0
ASX 26 32 24 31 / 30 20 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
LS...None.
&&
$$
UPDATE...Huyck
SHORT TERM...JTS
LONG TERM...LE
AVIATION...Huyck
Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
742 PM CST Sat Jan 25 2020
.SYNOPSIS...
Issued at 326 PM CST Sat Jan 25 2020
H5 analysis from earlier this morning had an area of
closed low pressure over northeastern Indiana with a trough of low
pressure extending south into the Florida Panhandle. West of this
feature, ridging was present from western South Dakota into southern
Manitoba. Immediately west of this feature, a shortwave trough was
located over central Montana. Another shortwave was present over
northern New Mexico. The latest satellite imagery this afternoon,
indicates a broad shield of mid level cloudiness tracking across the
Dakotas, as well as central and northern Nebraska. Earlier this
morning, areas of fog were present across northeastern portions of
the forecast area. That fog has since dissipated. Skies this
afternoon are partly to mostly cloudy and 2 PM CST temperatures
ranged from 32 at O`Neill to 55 at Imperial.
&&
.UPDATE...
Issued at 740 PM CST Sat Jan 25 2020
Cameras and radar suggest isolated sprinkles are underway across
northwest Nebraska and will continue for a few hours this
evening. A very weak midlevel disturbance will move east tonight
and presumably, the sprinkles will affect ncntl Nebraska.
&&
.SHORT TERM...(This evening through Sunday night)
Issued at 326 PM CST Sat Jan 25 2020
Over the next 24 hours quiet
conditions will persist across western and north central Nebraska.
Northwesterly flow aloft and low level westerly winds will lead to
mild temperatures across the forecast area. Was initially concerned
about fog development in the northeastern forecast area after dense
fog occurred in these areas earlier this morning. This morning`s
HRRR initialized well with the fog this morning. Utilizing the 12z
HRRR sfc visby product, fog will remain just off to the east of the
area overnight. Westerly winds will push through the forecast area
this evening as well, leading to decreased chances for fog
development. Lows tonight will be in the lower to middle 20s. Skies
will remain mostly clear to partly cloudy on Sunday as the forecast
area will be south of an approaching shortwave and cold front. Winds
will remain westerly through Sunday afternoon facilitating good
mixing and downslope conditions. This will lead to highs in the
lower 40s in the east, to the mid 50s in the southwest. By Sunday
night, a closed low will track southeast across eastern South Dakota
into western Iowa, forcing a back door cold front into the forecast
area from the northeast. The fropa will be dry as forcing for pcpn
will be well northeast and east of the area.
.LONG TERM...(Monday through Saturday)
Issued at 326 PM CST Sat Jan 25 2020
Temperatures behind the front will be
much cooler for Monday with highs ranging from around 30 in the
northeast, to the lower 40s in the southwest. By Monday evening, a
shortwave trough will dive south southeast along the front range of
Colorado and Wyoming, as well as the Nebraska Panhandle. Aided by
easterly upslope winds, light precipitation will develop in the
panhandle and spread east into west central and southwestern
Nebraska Monday night. The NBM initialized pops for the entire
forecast area Monday night. After collaborating with OAX and GID, it
was decided to cut pops out of our northeastern and far eastern
forecast area Monday night and keep them focused across west central
and southwestern Nebraska. A split flow regime will persist through
the middle and end of the work week. A system will track across the
desert southwest into the southern plains Thursday. At the same
time, a shortwave trough will lift across the Dakotas. Right now,
will retain a dry forecast, however, pops may need to be inserted in
the Thursday/Thursday night time frame if the models continue to
indicate this northern stream shortwave. A warm front will push into
the region Friday with a broad ridge of high pressure building into
the region next weekend. Other than some slight chance pops for
Friday night, dry conditions will carry over into next weekend with
much warmer temperatures.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 544 PM CST Sat Jan 25 2020
VFR is generally expected across western and north central
Nebraska tonight through Sunday afternoon.
The batch of midlevel clouds and sprinkles across wrn Nebraska
will move east and exit the region around 04z this evening. An
upper level disturbance across srn Saskatchewan will move
southeast tonight and send a cold front into nrn Nebraska late
Sunday afternoon. Indications are VFR will prevail as the front
moves through but there is a slight chance for MVFR ceilings along
and north of highway 20 after 21z Sunday.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...CDC
SYNOPSIS...Buttler
SHORT TERM...Buttler
LONG TERM...Buttler
AVIATION...CDC
Area Forecast Discussion
National Weather Service Marquette MI
525 PM EST Sat Jan 25 2020
.SHORT TERM...(This evening through Sunday)
Issued at 334 PM EST SAT JAN 25 2020
RAP analysis shows a 1007mb, close to vertically stacked, low across
eastern Upper Michigan. As this low has been slowly lifting through
the Great Lakes region, periods of snow, fog, and drizzle have
worked their way across the UP. Dewpoints across the cwa remain
close to 32F this afternoon, as temperatures have climbed to near 35
across central and eastern UP. As temperatures have climbed, this
morning`s fog has slightly lifted...but ample moisture in the low
levels remains, as do the low ceilings.
As the low continues to slowly depart to the east tonight, model
reflectivities suggest additional round of -SHSN to move across the
UP...this time from west to east. There are slight discrepancies
across the model soundings wrt cloud ice, but where models show -
shsn, saturation through the DGZ is present. Due to this, went with
slight -DZ/-FZDZ chances, but mainly stuck with snow for the
hydrometeor. With that, expecting 1 to 2 inches of fresh snow
tonight, with most of those amounts remaining north and in the
higher terrain. Elsewhere, up to an inch as temps in the mid 30s
will keep initial precip as drizzle. Fog chances will remain tonight
with a ripe snowpack and ample low-level moisture as temperatures
begin to fall tonight.
Tomorrow, a few snow and drizzle chances will remain...but mainly
along Lake Superior as models suggest. High-res guidance suggests
Lake Superior enhancement, but with 850 temps remaining in the -5 to
-6C range...it remains slim for most of the chances. With that, have
left most of the accumulations low, and in the morning. These
chances will bring snow accumulations of a half an inch or so, but
low clouds should hang on through the day with lingering moisture.
.LONG TERM...(Sunday night through Saturday)
Issued at 310 PM EST SAT JAN 25 2020
Overall, a fairly quiet weather week is on tap as the main, pesky
cutoff low continues to exit the region early next week. A few
shortwaves look to dig south across the region through mid-week, but
surface ridging starts to dominate mid-week as split flow develops
and upper-level ridging builds across the Upper Great Lakes.
Temperature wise, expect the mild January temperatures as of late to
persist, with a brief, subtle cool down mid-week, and the return of
above normal temperatures to end next week. Towards the end of next
weekend, deterministic models do show the potential for some colder
air working into to the region, but overall there is uncertainty in
where, when, and how cold. Overall, we`re going to continue to put
up with these above normal-temperatures for much of the upcoming
week.
Sunday night into Monday, shallow, upslope northerly flow looks to
persist across the region with 850mb temps hovering around -5 to -
6C. This lack of colder air aloft, and further examination of
forecast soundings supports more freezing drizzle than snow showers.
So have trended the forecast from a freezing drizzle/snow mix Sunday
evening to straight freezing drizzle overnight into Monday morning.
Additional examination of the probability of cloud ice among the
deterministic models all showing no ice also aided in this decision.
Have kept QPF on the very low end (0.01 to 0.02`` at most) and still
end up getting a bit more ice accretions in the forecast than would
like, so expect at least a glaze of ice to be possible, especially
on elevated and untreated surfaces across the higher terrain out
west and in the north-central. Elsewhere, conditions look to remain
mostly dry, especially across the south-central. As we progress
throughout Monday, 850mb flow backs more westerly with some slightly
colder air moving into the region. This should help transition
precipitation back over to light snow later in the day across the
upslope regions across the west and north central. The south-central
and east look to remain mostly dry right now.
Tuesday through Thursday, a train of shortwaves will dig south
across the Upper Great Lakes so there will be occasional
opportunities for wintry precipitation. Overall, nothing major as
these shortwaves look to lack overall moisture with surface high
pressure extending southwest from the Hudson Bay area bring in some
drier air, after the initial shortwave arrives on Tuesday.
Thursday night into next weekend, surface high pressure over the
Hudson Bay area shifts east over the Northeast, as a wave over the
northern Rockies ejects out over the northern Plains and pivots over
the Upper Great Lakes region. This will bring back widespread
chances for snow, especially late in the week into next weekend.
Much further south, the stream stream/end of this wave looks to keep
the Gulf Moisture (and any other tropic connections for that matter)
in check, so we will have to see what moisture this system has to
work with, and if any lake-enhancement will be possible. Given the
current track of this system, the best chance for lake-enhanced snow
would be off of Lake Michigan out east in spots. Otherwise, once the
system passes, if the colder air behind this system does pan out, we
should see the return of lake-effect snow next week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 525 PM EST SAT JAN 25 2020
As an area of low pressure continues to slowly lift north through
the Great Lakes region and will leave low-level moisture and IFR, to
at times LIFR, cigs at all terminals. As this low pressure system
begins to move north and east of Upper Michigan tonight, expect -SN
to spread across the UP from west to east and slowly taper off by
Sun morning. With temperatures hovering around freezing and the
snowpack remaining ripe, fog and mist will remain possible at all
terminals with IFR vsbys prevailing through most of the forecast
period.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 334 PM EST SAT JAN 25 2020
Northerly winds approaching 25 knots will be possible tonight into
tomorrow afternoon as a low pressure system exits the Great lakes
region. Winds then remain light and below 20 knots through the
forecast period.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...JAW
LONG TERM...Ritzman
AVIATION...07
MARINE...JAW