Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/09/21
Area Forecast Discussion
National Weather Service Bismarck ND
1002 PM CST Mon Mar 8 2021
.UPDATE...
Issued at 950 PM CST Mon Mar 8 2021
00Z guidance continues to suggest that mesoscale banding of
precipitation will be possible across far northwest North Dakota
mid Tuesday morning through the early afternoon. Little change in
forecast thinking from the previous update discussion regarding
this potential. One thing to add is that surface temperatures at
the time of heaviest precipitation are expected to be near to
slightly above freezing, which could yield rain, snow, or a mix
thereof. This introduces more uncertainty for snow accumulation
potential.
For this update, we increased PoPs and QPF mainly across
Williams, Divide, and Burke Counties. Our maximum event total QPF
of around 0.10" matches well with that of the 00Z HREF localized
probability-matched mean. Though looking at its individual
members, it is more of a bimodal solution (less than 0.05" vs.
around 0.25"). Because of the precipitation type uncertainty and
low snow-to-liquid ratios, these adjustments only resulted in a
total snow accumulation forecast of up to one half inch, highest
in Divide County. At this point, the worst-case scenario appears
to be around 2 inches of very wet, slushy snow. But to
reemphasize, that is not the most likely outcome at this time.
UPDATE Issued at 635 PM CST Mon Mar 8 2021
The main forecast consideration for the next 24 hours is
evaluating the potential for a brief mesoscale banded snow event
in far northwest North Dakota Tuesday morning.
The 18Z NAM/NAMNest and 21Z RAP have arrived with a stripe of
around 0.25" QPF across far northwest North Dakota, mostly falling
from mid to late morning. This is quite the dramatic increase from
the 12Z model suite, which averaged little to no QPF across the
same area. Examination of dynamic and thermodynamic fields in
guidance shows the potential for a band of heavy snow is
certainly greater than zero. Several factors that could be present
include left exit region jet dynamics, strong Q-vector
convergence, steep lapse rates within the DGZ, strong mid level
frontogenesis, and EPV near zero. However, not every model core
contains all these features in the same place at the same time.
For this update, we made some slight increases to PoPs and QPF
across the far northwest, but this really does not change the
overall messaging at this time. We will wait to evaluate the 00Z
guidance and also see if this trend continues in hourly-updating
guidance before making more drastic changes to the forecast. Even
if a band of heavy snow does materialize, very low snow-to-liquid
ratios (around 8:1 at most) should keep snow rates and amounts
lower than would be expected for a typical banded snow event.
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 222 PM CST Mon Mar 8 2021
Current surface analysis places ridge over the upper midwest with
low over the Wyoming Bighorn Mountains. Upper level analysis
places ridge over the northern plains into the midwest, with
trough over the west coast. A variety of modest disturbances noted
in the flow ahead of aforementioned trough. Quiet weather with
some passing clouds continue here under the ridge, with very warm
temperatures running 20 to 30 degrees above average. Bismarck,
Jamestown, and now possibly Minot have already eclipsed their
record highs for the day.
For tonight, ridge axis pushes to the east with southwest flow
setting up over our area. A fast moving short wave sliding through
the flow makes its approach overnight, while aforementioned
surface low ejects northeast, passing over central North Dakota
near daybreak. Cooler air starts pulling in behind the low late
tonight. Precipitation develops north and west of the low mainly
out of our area, though a little bit may work its way into
northern locations.
On Tuesday, surface low pushes to the northeast through the day,
sliding over the Minnesota/Ontario border around sunset. As the
cold front behind the low swings southerly, cooler air pushes into
our area. This will lead to quite a temperature gradient, with
highs around 40 over the northwest and around 60 over the James
River Valley. High temperature forecast is a bit tricky as it
depends on the timing of the front and cooler air pushing in.
Modest chances for light rain/snow remain over northern areas
through the day, diminishing in the evening.
.LONG TERM...(Wednesday through Monday)
Issued at 222 PM CST Mon Mar 8 2021
On Wednesday a secondary low passes through the central plains,
but will be far enough south to keep most precipitation out of
our area. With that said, a little could sneak its way into our
southern areas including the James River Valley. Thereafter, a dry
forecast is on tap. Temperatures will be near to a bit above
average.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 635 PM CST Mon Mar 8 2021
VFR conditions are expected across southern North Dakota through
the forecast period. For northern North Dakota, ceilings are
expected to lower to MVFR Tuesday morning. Some rain or snow is
also possible across northern North Dakota Tuesday morning and
afternoon, especially at KXWA. Southeasterly winds this evening
will eventually transition to west-northwest by Tuesday afternoon
as a center of low pressure and cold front move across the state.
Winds speeds will increase to 15-20 kts Tuesday afternoon, with
gusts near 30kts. A few hours of low level wind shear concerns are
expected at KBIS and KJMS late tonight.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Hollan
SHORT TERM...JJS
LONG TERM...JJS
AVIATION...Hollan
Area Forecast Discussion...Updated
National Weather Service Billings MT
901 PM MST Mon Mar 8 2021
.UPDATE...
Heights were lowering as shortwave trough advances through the
area from the west. This was dragging a cold front across western
and central zones this evening, with areas of light precipitation
developing behind the frontal passage. Stronger forcing was
clearly northwest of the area, and for the most part, the
strongest forcing will stay north. That being said, frontogenesis
will create enough lift for likely PoPs west of Billings tonight.
Not expecting a great deal of QPF, as low levels were still on the
dry side, but the GFS/ECMWF/RAP were all pointing to an area of
light snow developing this evening and swinging east across the
central zones, into parts of the southeast. The HRRR was the least
ambitious of the models. Raised PoPs tonight and Tuesday morning
to account for this. TWH
&&
.DISCUSSION...
Rest of Today through Wednesday Night...
Benign weather with east winds keeping temperatures around a
modest upper 40s to low 50s will persist through the afternoon.
Upslope flow and weak mid-level moisture will still allow a very
small chance for snow showers to occur in the foothills west of
Billings this afternoon, but for now it continues to occur as
virga.
Tonight, a cold front will swing across eastern Montana, bringing
with it a few inches of snow to the mountains, especially on south
to west facing slopes, and a small chance for light snow across
south- central Montana. For the lower elevations, no major
accumulations are expected, amounts will generally be under an
inch if snow even occurs in the first place. Despite the cold
front passing through, low will stay similar to last night and
only get down to the upper 20s. Northwest to downslope flow
persists throughout Tuesday as a surface low moves east across
the Dakotas. Good mixing looks to occur to mix down winds that
look to gust 30-35 mph across much of southeast Montana, and light
snow will continue to occur in the mountains.
Tuesday night through Wednesday, a shortwave moving through Wyoming
will bring more snow to the mountains, especially the Bighorns.
The bighorns look to get 3-6 inches throughout the day, with maybe
a couple inches in the foothills in far southern Sheridan County.
Most snow should be retreating from the area throughout the
afternoon. Vertz
Thursday through Monday...
Cyclonic flow over the region on Thursday will give way to a rex
block by Friday, as ridging builds over the Northern Rockies, and
a cut off low moves underneath into the four corners region.
Cooler temps and showers over portions of the area on Thursday
will be followed by above normal temperatures and drier
conditions for Friday through the weekend. More unsettled weather
is possible for early next week with the cut off low lifting off
to the north and east, opening the door for additional weather
systems to move through the region.
High temperatures on Thursday are forecast to range from the
upper 30s to 40s, warming into the 40s and 50s Friday through
Sunday. 30s and 40s for Highs are possible early next week. Low
temperatures in the 20s can be expected most nights through the
extended. STP
&&
.AVIATION...
Cold front will push E through SE MT and N central WY overnight,
ushering in northerly surface winds and areas of snow. The snow
will affect areas from KMLS to Lodge Grass W, as well as the NE
Bighorn Mountains. Expect MVFR conditions in the snow with
localized lower conditions possible. The western mountains will be
obscured. The snow will continue Tuesday morning, but will taper
off to rain and snow over the mountains and foothills in the
afternoon. Arthur
&&
.PRELIMINARY POINT TEMP/POPS...
Tue Wed Thu Fri Sat Sun Mon
-----------------------------------------------------------
BIL 031/049 028/046 026/045 026/049 027/052 030/057 029/046
43/S 12/S 11/U 11/U 00/U 01/U 12/S
LVM 032/043 026/040 022/042 023/044 023/048 028/053 028/043
63/S 21/B 11/U 10/U 00/U 01/U 12/S
HDN 030/051 026/046 024/046 024/050 023/054 026/058 026/048
33/S 12/O 11/U 11/U 10/U 01/U 12/S
MLS 032/047 024/045 023/043 021/048 023/051 025/054 025/043
22/S 01/B 00/U 00/U 00/U 00/U 11/B
4BQ 032/049 026/043 025/045 023/048 024/050 025/052 025/044
11/N 13/S 00/B 00/U 00/U 00/U 11/B
BHK 030/047 022/041 022/043 018/046 020/048 023/051 021/040
11/N 01/E 00/B 00/U 00/U 00/U 11/B
SHR 027/048 024/038 019/042 018/045 020/047 021/051 023/044
12/O 56/S 21/B 11/U 11/U 11/U 12/S
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...None.
WY...None.
&&
$$
weather.gov/billings
Area Forecast Discussion
National Weather Service Grand Rapids MI
1006 PM EST Mon Mar 8 2021
LATEST UPDATE...
Update
.SYNOPSIS...
Issued at 221 PM EST Mon Mar 8 2021
- Freezing fog risk tonight to Tue AM
- Rising rivers into the weekend
- Gusty winds especially Wed night to Thu
&&
.UPDATE...
Issued at 1006 PM EST Mon Mar 8 2021
I believe there is still the threat of some patchy fog, mostly
north of I-96 but I do not believe widespread dense fog is
likely. Only the NAMnest is showing fog and the 00z run is showing
less. The RAP and HRRR models do on show much fog, expect near
Saginaw Bay. Typically to get dense fog a would want to see
significantly more moist are moving over the shallow layer of cold
air. Tonight while we do have a front that is stalled just north
of I-96 the air south of the front is not all that moist. So the
bottom line is patchy fog. I see no need for headlines at this
time.
&&
.DISCUSSION...(This evening through next Monday)
Issued at 221 PM EST Mon Mar 8 2021
- Freezing fog risk tonight to Tue AM
A weakening cold front will drop down from the northwest tonight
and dissipate over the region. As winds taper off and temperatures
cool down a risk for fog/freezing fog could develop. Several
models including the NAM show a sharp increase in the RH values
after midnight. Other models like the HRRR do not show much at
all. With temperatures likely to fall below freezing especially
northeast parts of the CWA...we will carry a local freezing fog
risk. We are not confident enough to go with a headline at this
time given the spread in the models.
- Rising rivers into the weekend
The combination of an inch or so of rain and melting snow is
forecast to generate rising rivers. At this time this would
generate only local minor issues if any on smaller streams and
creeks. The main concern would be if end up with 2 or more inches
of rain. While not the most likely scenario...it is something we
will need to monitor closely. We could end up with issues on the
mainstem rivers if basin average amounts start going over 2
inches.
- Gusty winds especially Wed night to Thu
A stronger low level jet moves in later Wednesday into Thursday.
Winds at 850 mb rise into the 40 to 50 knot range. It is not
expected to mix to that depth then...but gusts in the 30 to 35
knot range look likely. This would be enough to cause isolated
power outages. If mixing heights end up deeper we could see higher
winds. For now we will continue to highlight the potential in the
HWO and social media posts.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 631 PM EST Mon Mar 8 2021
Gusty winds this evening will subside quickly as the sun sets. A
weak cold front comes through this evening too and that will help
to diminish the winds.
There is some question about fog toward morning. With the weak
front having come through we will be in slightly cooler air and
toward morning the front will head back toward us as a warm front.
However the air heading into this area is not overly moist at this
point. So, I do not think we will see a widespread dense fog
event. Seems Lansing has the highest risk bases on it being the
deepest into the colder air at sunrise. Also there is some
suggestion fog from Saginaw Bay may advect in at low levels.
Whatever fog does develop it will be shallow and should mix out
quickly. Tuesday for the most part should be a day with only high
clouds (those will be thin) and winds around 10 knots from the
southwest at the surface.
&&
.MARINE...
Issued at 221 PM EST Mon Mar 8 2021
While a stronger low level jet moves Wednesday night into
Thursday...the limited mixing height is expected to keep the
winds under gale criteria. We will likely need another small craft
advisory then. We will likely issue one later tonight or on
Tuesday.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
LM...None.
&&
$$
UPDATE...WDM
SYNOPSIS...MJS
DISCUSSION...MJS
AVIATION...WDM
MARINE...MJS
Area Forecast Discussion
National Weather Service Northern Indiana
631 PM EST Mon Mar 8 2021
.SYNOPSIS...
Issued at 228 PM EST Mon Mar 8 2021
Afternoon highs in the low to mid 60s and lows in the 40s will be
the theme into mid week before a cold front arrives, bringing
shower chances to the area by late Wednesday night into Thursday
night. Breezy conditions are expected into Tuesday with stronger
wind gusts possible Wednesday afternoon in advance of the cold
front.
&&
.SHORT TERM...(This Evening through Wednesday)
Issued at 228 PM EST Mon Mar 8 2021
Plenty of sunshine is allowing well mixed low levels, resulting in
temperatures well in the 60s and some wind gusts in the 25 mph or so
range. A weak disturbance was stirring up some mid clouds but these
should quickly dissipate into the evening. Expecting a carbon copy
of today in terms of temps and winds on Tuesday. Some models are
giving some increased mid/high cloud cover once again. Bit skeptical
on total sky cover being much more than 50% so some minor changes
have been made. Clouds do look to become more of a factor on Weds as
low level moisture begins to increase. Have left the mostly cloudy
skies in for now. Increasing PWATs/Mixing ratios will be well
underway into Weds afternoon, but lack of pronounced trigger
suggests limited (if any) threat for some shower activity until the
start of the long term period.
With regards to afternoon dewpoints/humidity values, overall
consensus was decent potential for mixing of much lower dewpoints
that NBM and other models suggest. Have done some blending between
current grids and RAP with HRRR most aggressive (dewpoints in the 20s
in some areas).
Last but not least, wind gusts of 25 to 30 mph even a bit higher
in spots today) will likely occur again Tuesday afternoon with
stronger gusts to 40 mph Wednesday afternoon.
&&
.LONG TERM...(Wednesday Night through Monday)
Issued at 228 PM EST Mon Mar 8 2021
Large cut off upper low will remain across the SW US, with a
perturbed SW flow maintaining itself for several days. Impacts to
our area remain greatest Thursday into Thursday night as baroclinic
zone will approach and edge slowly SE. Some models are not overly
impressed with QPF potential while others are much more aggressive.
Blend of models lowered pops once again, but have held with
previous forecast with high likely to cat pops Thursday into
Thursday night. QPF did come up somewhat with overall rainfall now
between 1 and 1.5 inches, with some areas possibly seeing a bit
more. Some hydro concerns could occur (action to minor flood stage
on rivers and ponding of water in low areas). I do have some
concerns with those models showing less QPF as best dynamics will
be well removed from the area and could limit overall QPF/precip
coverage. Have continued to keep any mention of thunder out as
best chances seem to remain west of us Weds night and south into
Thurs.
EC more aggressive on pushing front south of the area Friday into
the weekend with GFS remaining a bit further north. Given the
proximity of the front and impacts of each wave in question on the
position have left in slgt chc to chc pops across the south into
Sunday. The main upper low will finally begin moving east and then
get a huge nudge north as strong ridge over the SE states refused
to budge. This may send a swath of rainfall to the area late in
the period, bit a lt of the dynamics will be shifting west so not
sure what if any impacts it will have here. Plenty of time to
watch evolution of this feature.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday Evening)
Issued at 624 PM EST Mon Mar 8 2021
VFR conditions to persist once again this forecast cycle with wind
gusts once again Tuesday afternoon as the main concern. Gusty
winds with deep mixing earlier this afternoon will quickly
diminish this evening as low level decoupling occurs. Winds
should diminish into the 5 to 10 knot range over the next hour or
two as this occurs. A very weak cold front dropping across the
southern Great Lakes has resulted in a wind shift to west-
northwest at KSBN. This front will make little if any additional
progress to the south which will keep a weak southwesterly
gradient in place tonight. After sfc ridge axis passes across the
Great Lakes tonight, a fairly strong gradient will set up again on
Tuesday with another good mixing day. Expecting wind gusts to be
slightly lower than today, generally in the 20 to 25 knot range
for Tuesday afternoon. A band of mid level clouds will drop
southeast across northern Indiana this evening, and will be
replaced by mainly sct-bkn high clouds through remainder of the
period.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...Fisher
SHORT TERM...Fisher
LONG TERM...Fisher
AVIATION...Marsili
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Area Forecast Discussion
National Weather Service Marquette MI
949 PM EST Mon Mar 8 2021
.SHORT TERM...(This evening through Tuesday)
Issued at 258 PM EST MON MAR 8 2021
Current RAP analysis and GOES WV imagery show a shortwave that was
responsible for the clouds, breezy winds, and very light pcpn
yesterday is moving off to the northeast towards the James Bay with
high pressure taking control over Upper Michigan today. As the high
moves overhead, stubborn clouds that were around the north and ease
will clear out except for the far east around Newberry and the
Mackinaw Straits. Otherwise, expect partly to mostly sunny skies for
the afternoon and evening. With the clearing and light winds
tonight, areas of patchy fog are possible tonight with more moisture
in air as dewpoints from the afternoon will be in the upper 20s to
low 30s. Clouds will slowly begin to filter back in early Tuesday,
continuing through the day as a sfc low will track up through the
northern plains with the high shifting slightly east towards New
England. This will result in tightening pressure gradient again,
bringing breezy south to southeast winds for the afternoon and
evening Tuesday. Could see higher gusts along the Lake Superior
shoreline in the downsloping areas. Next chance of pcpn will come
late Tuesday into Wednesday ahead of next system.
Temperature will be once again unseasonably mild for this time of
year as our average high is only 32. Highs this afternoon will be in
the 40s to low 50s across the south along the WI border. Lows
tonight will mostly in the 20s with some upper teens over the
traditional cool spots in the interior west. Tomorrow will be
slightly warmer with more waa moving in with breezy southerly winds
across the area with mid to upper 40s for the east with the cooler
air from Lake Michigan but 50s are likely across the west half and
maybe even a 60 along the WI border.
.LONG TERM...(Tuesday night through Monday)
Issued at 330 PM EST MON MAR 8 2021
A warm and mild night looks to still be on track Wednesday night as
the region continues to find itself under the influence of an
unseasonably warm and moistening airmass. Shortwave and surface low
passing just north of the lake will push northeast, resulting in the
gradual reduction of the pressure gradient across the area. Winds
could still be a little gusty across the highlands of Marquette and
Baraga counties, as well as in the east through the early morning
hours. Where winds remain lighter through the night, expecting areas
of fog developing given the likely ripe snow and warmer/moist
airmass, particularly along the WI/MI state line and south central.
The fog and warmer airmass will really limit how low temps get, and
I`m generally expecting widespread low 40s across the region.
Attention then turns upstream to a low ejecting out of the Plains
early Wednesday. Models have been consistent with this system
tracking northeast into the Upper Great Lakes, with moderate rain
overspreading the area by Wednesday afternoon and persisting into
the overnight hours. From there the lack of a detailed consensus
raises a lot of questions. As with the previous forecast package,
there still seems to be two camps on where the system will track and
thus, where the cold air on system`s west/northwestern side will be.
The options appear to be the western UKMET/Euro solutions and then
the more eastern GFS/NAM/Canadian solutions. The western solutions
keep the cold air in Minnesota as the low scoots through western
Lake Superior. Its also noteworthy that the UKMET trended further
west between the 0z and 12z runs. This presents mainly an all rain
forecast due to the influence of the warmer airmass. The eastern
solutions bring the low somewhere between the central or southern UP
and Sault Ste. Marie. These have been consistent also cooling at the
surface which would allow rain to change to freezing rain before the
column cools further and transitions to snow on the western side of
the low. Like yesterday`s guidance suite, some are hitting the
freezing rain hard. Given the uncertainty in the position of the
system and subsequent atmospheric variables, I`m still skeptical
where this feature would end up. I`m even more skeptical of the
there being significant impacts if it does materialize given the
expected antecedent conditions that would limit freezing to surfaces.
On Thursday, a brief area of high pressure is expected to build in
behind this departing system. This ridge should bring the region
mostly dry conditions Thursday afternoon and overnight into Friday
morning. The colder air behind this system will help cool temps a
little on Thursday. At the moment, low-mid 40s are expected. By Lake
Superior and in the Keweenaw I expect it to be cooler, with near 40s
and mid 30s, respectfully. By Friday, CAA will increase behind a
weak cold front, bringing more seasonable temps. Most of the region
should see highs in the 30s to near 40F south-central. Along this
boundary, some light snow showers may move through the region, but
soundings suggest an inverted v. So any accumulation would likely be
hard to come by. The weekend looks dry, as mid-upper level ridging
extending from the Gulf gradually shifts east through the region.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday evening) Issued
at 948 PM EST MON MAR 8 2021
VFR conditions are expected for all sites until Tue evening when
MVFR cigs move in. Some LLWS should work from west-to-east Tue, with
KIWD seeing LLWS starting in the morning, KCMX seeing LLWS starting
in the early afternoon, and KSAW seeing LLWS starting in the late
afternoon. This LLWS, associated with a low pressure passing to our
west, should continue to and past the end of the TAF period as
another low pressure approaches the area from the southwest. The
wind will get gusty at all sites on Tue as well.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 258 PM EST MON MAR 8 2021
Winds have been slow to ease as the shortwave from this morning is
slowly moving away. Winds will fall below 20 knots tonight into
Tuesday before turning south to southeast Tuesday afternoon and
increasing to 20-30 knots over the central and eastern parts of the
lake with a few gale force gusts to 35 knots possible. Winds will be
at or below 20 knots Wednesday morning and becoming northerly. A
cold front will cross the lake on Friday, increasing to 15-25 knots
with the potential for gales as well.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...JH
LONG TERM...JP
AVIATION...07
MARINE...JH