Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/10/21
Area Forecast Discussion
National Weather Service Bismarck ND
1003 PM CST Tue Mar 9 2021
.UPDATE...
Issued at 1001 PM CST Tue Mar 9 2021
A mix of clouds over the area tonight as low clouds stream from
northwest towards the southeast, while high clouds stream over the
area from southwest to northeast. So, long story short, its cloudy
out over most areas. Going forecast has this handled well.
UPDATE Issued at 635 PM CST Tue Mar 9 2021
For early evening update have added some low snow chances over the
far north for the next few hours as observations just north of the
border are indicating a little bit of snow. Have also increased
cloud cover through the area.
&&
.SHORT TERM...(This evening through Wednesday night)
Issued at 109 PM CST Tue Mar 9 2021
Main forecast issue in the short term period will be precipitation
chances late this afternoon and this evening north and west, then
Wednesday through Wednesday night south.
A surface low is located over east central North Dakota with wrap
around moisture containing rain/snow showers along the
International Border and into far northeast Montana. The southern
half of ND remains partly cloudy to mostly sunny, but winds here
have picked up and expect breezy to at times windy conditions
through the afternoon and into early this evening. For the most
part, expect any precipitation to remain along the far north.
However, a few late afternoon showers are possible in the far west
given the increased moisture advecting into the area, with steep
late afternoon lapse rates.
Tonight...High pressure builds into the northwest and our
northwest flow in the evening turns more northerly overnight and
northeast to east early Wednesday morning. This will help bring
cloud cover southward and should cover most of the forecast area
with MVFR to IFR ceilings (see Aviation discussion). Latest RAP
and HRRR also bring some lower visibilities into western ND late
tonight, likely along the western fringes of any low level stratus
deck. Will add a mention of patchy fog west.
Wednesday and Wednesday night the attention shifts to our
southern border as a shortwave just moving onto the California
coast will make it`s way into the northern/central High Plains
late tonight into Wednesday morning, then into west central
Minnesota by 00 UTC Thursday. This will bring a swath of
precipitation to mainly South Dakota but will clip the far
southern James River Valley into southeast ND. We utilized the NBM
blend for pops with WPC qpf. Looking at the WPC ensemble solutions
there remains quite a bit of spread, with some ensembles placing
moderate qpf as far north as Jamestown and Carrington, while
others keep qpf practically out of the CWA. A blended solution
with WPC qpf seems reasonable at this time, which would bring 2-4
inches of snow to far southeast portions of Dickey County, with
maybe an inch or two from Southern Mcintosh to eastern Lamoure
counties, and the remainder of Dickey County. This would still
leave time for a possible advisory should snow amounts shift a bit
north as At this time it looks like the accumulating snow would
probably hold off until Wednesday afternoon.
.LONG TERM...(Thursday through Tuesday)
Issued at 109 PM CST Tue Mar 9 2021
Precipitation exits the James River Valley late Wednesday evening
with high pressure building over the northern forecast area on
Thursday behind a northern stream shortwave. This will bring much
colder temperatures aloft into the northern forecast area during
the day, making for a much colder afternoon along the
International Border (25 to 30 degrees) compared to the southern
tier counties (middle 40s). Given our time of year would not be
surprised to see a few rain/snow showers, mainly north central
into eastern ND, but at this time our blended guidance is not
producing anything. Will not add any precip at this time but will
pass it along to monitor as there could be a period of winds/snow
showers Thursday afternoon.
Beyond Thursday it`s looking more and more like a period of mild
and dry weather through the upcoming weekend with a high over low
blocking pattern taking shape over the central portion of the U.S.
North Dakota will be under the strong upper ridge extending from
the northern plains well north into Canada, with a cutoff low
tracking slowly from the Desert Southwest into the Southern
Rockies/Southern Plains by Sunday. Our NBM Ensemble spread fairly
reasonable Friday into Saturday with temperatures warming well
into the 50s southwest and south central Saturday, likely the
warmest day of the extended period. On Sunday you can see the
spread increase a bit, which is reasonable given the the upper
level pattern at this time. A Eastern Pacific upper level trough
is the kicker that pushes the southern Plains low east, but how
this eventually occurs, is the issue. This can be seen in the NBM
temperature Ensembles that develop by next week. A modest spread
early in the weekend, increases a bit Sunday, then significantly
widens next Monday through Wednesday with on the order of 20 to
30 degrees difference between the 25th and 75 percentiles for max
temperature. Looking at the cluster analysis for this period
indicates that any one of the for cluster solutions remains
possible, including the wettest solution. However given the
background flow this high over low blocking pattern, this seems
like it may be a less likely solution, but yet within the envelope
of possible solutions. Therefore we will hold off on any changes
in the extended period. The NBM solution does bring some slight
chance pops into the south Sunday evening, then slight chance pops
north and chance pops south on Monday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 635 PM CST Tue Mar 9 2021
Widespread MVFR with localized IFR ceilings expected tonight into
Wednesday morning. Ceilings will improve from north to south
Wednesday morning, but will remain MVFR through the day over the
far south. Snow is expected over the southern James River Valley
on Wednesday, which may result in MVFR to IFR visibility at times.
Most snow will remain south of KJMS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...TWH
LONG TERM...TWH
AVIATION...JJS
Area Forecast Discussion
National Weather Service Des Moines IA
533 PM CST Tue Mar 9 2021
...Aviation Update...
.DISCUSSION.../Tonight through Tuesday/
Issued at 316 PM CST Tue Mar 9 2021
Tonight:
The dry air early this afternoon has seen a boost in dewpoints with
the strong southerly winds advecting in an airmass with higher theta-
e. As a result, RH values have reached above 50 percent late this
afternoon. The winds are still quite gusty though, still making for
fire weather related concerns. Burning today is still discouraged.
With the push of greater moisture, there could be some fog concerns
in areas that cool off rapidly. However, temperatures will not
drastically drop off tonight, and the flow should remain strong
enough to mix out any fog development. Only areas areas blocked from
wind may see visibility reductions. Because of the large number of
limiting factors, have kept fog out of the official forecast for
this evening.
Wednesday and Thursday:
Ahead of the deeper trough over the western CONUS a short-wave
trough has ejected out ahead of it within the broad southwest flow.
H5 winds have increased to around 50-60 kts with this feature, and a
decent amount of cyclonic vorticity has developed. At the surface
lee cyclogenesis has begun, with WAA and dCVA lining up favorably to
allow the cyclone to deepen. This will continue to enhance the low-
level southerly flow through, and likely enhance the development of
the LLJ through the early morning hours. Isentropic ascent will
begin early Wednesday morning as the cyclone tracks toward the
northeast along with the short-wave trough. Most of the available
guidance depicts some pre-frontal surface troughing along in the
northeast quadrant of the system, which will put a kink in the low-
level flow early on. CAMs have been pointing to elevated convection
developing in west-central Iowa and moving toward the northeast. Mid-
level lapse rates will be between 6.5-7.5 C/km, with moderate wind
shear during this time that may support the development of small
hail. MUCAPE may be a bit difficult to come by though early in the
morning, which would limit the threat for severe storms with the
first round in the morning. By the middle of the afternoon, CAMs and
synoptic models show a dry slot working through the area. Expect to
see a break at least from precipitation at some point, but the big
question will be how much lingering cloud cover there is from early
morning convection. Behind the surface cyclone, a stronger cold
front will be trailing. In previous days, the better wind shear and
helicity was mainly behind the cold front and displaced from the
stronger convergence that would trigger thunderstorm development.
However, over the past 12-18 hours, the HRRR especially has been
developing a better shear environment just ahead of the cold front
that could result in organizing a slightly stronger line of storms.
However, instability will the biggest question. If the dry slot
clears out lingering cloud cover, SBCAPE values could reach as high
as 1500 J/kg by Wednesday late afternoon ahead of the cold front. A
few models do have this, but the mean of the 12z HREF struggles to
reach 1000 J/kg. Should this instability be realized and storms
develop ahead of the boundary in an environment with 0-6 km bulk
shear of 50 kts and 0-1 km SRH between 150-200 m^2/s^2, an isolated
severe storm is possible. Hail around 1" could develop, and a spin-
up or two may materialize. Again though, this is conditional on
having this instability. As is typical with early Spring setups, the
deep layer shear is there but ability to destabilize the convective
boundary layer is questionable. There was discussion with SPC and
our neighboring offices this afternoon regarding the strong cold
front and slightly better shear environment. With the questionable
instability, the marginal risk will be kept mainly over Missouri for
the Day 2 outlook. If the system continues to trend in the direction
that the 12z HRRR started though, an expansion of this marginal risk
may become necessary. If a severe threat is to develop, it appears
now it will have a narrow window to do so, at least for our forecast
area. Thursday, cold front passes through and surface high pressure
moves in to clear out conditions, and bring cooler temperatures.
Friday and Beyond:
Surface high pressure will be rather strong, and now will keep a
second system mainly south of Iowa on Friday. The furthest southern
counties may see a trace amount of precipitation, but the trend
continues for this to push southward. For the rest of the area,
looking at dry and cool conditions through much of the weekend. A
bigger system is forecast to move thorugh Sunday into Monday. 12z
deterministic GFS and ECMWF have come into somewhat better agreement
on the track, but in the ensembles there is still spread in QPF and
snowfall amounts. Temperatures with this system will be cool enough
where if precipitation does happen, it will eventually turn to snow.
Accumulating snow will be possible, but at this time there is too
much spread to pinpoint exact details.
&&
.AVIATION.../For the 00Z TAFS through 00Z Wednesday evening/
Issued at 529 PM CST Tue Mar 9 2021
Strongest winds and gusts have eased late this afternoon with peak
mixing loss, but may continue to see around 20 to 25 kt gusts over
the next couple of hours. Overnight, cloud cover will increase and
ceilings will drop as low pressure encroaches on the area,
eventually settling into widespread MVFR territory around/after
06z with IFR possible. Precipitation chances will also ramp up
around/after 06z and linger around most TAF sites, potentially
through the remainder of the period. Greatest precipitation
chances will be around KFOD/KMCW/KALO as the warm front settles
into northern Iowa and southern Minnesota.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION...Krull
AVIATION...Curtis
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
531 PM CST Tue Mar 9 2021
.Discussion...
Issued at 318 PM CST TUE MAR 9 2021
Key messages:
- Strong winds are possible overnight but are expected soon after
sunrise tomorrow morning into the afternoon hours.
- Strong to potentially severe storms are possible tomorrow evening
into the overnight.
Detailed discussion...
A strong low-level jet will develop overnight as a trough deepens
across the western states. Strong moisture advection should lead to
some cloud cover and possibly some showers overnight into tomorrow
morning before that activity lifts to the north. It`s possible that
overnight, if mixing remains deep enough, that some strong wind
gusts of 40 to 50 mph develop overnight. It`s more likely that after
sunrise tomorrow morning, wind gusts will quickly increase with
gusts of 40 to 50. What makes this uncertain, still, is the
potential for thicker lower-level clouds and their inhibiting deeper
mixing. The NAM tends to have a thicker and lower cloud base that
inhibits how deep mixing is and thus limits wind potential. The
GFS, while still developing clouds, is higher with the base and
higher with the mixing and as a result is stronger with the wind
gusts. The RAP and the HRRR are more like the GFS but stronger
overall. Have trended toward a RAP/HRRR/GFS approach. This keeps
winds gusty overnight but really increases them after sunrise
tomorrow into tomorrow afternoon. Given the potential for strong
winds, have issued a wind advisory for the western two-thirds of
the forecast area from 13Z to 23Z tomorrow.
With very strong winds aloft tonight into tomorrow, and the
potential for showery activity with the strong moisture advection,
it`s possible for some of these showers to bring down some of the
strong winds aloft leading to locally higher wind gusts with a
passing shower.
A cold front will track into the area tomorrow afternoon and
evening. The air mass this front is advancing into will be capped
during the day with a narrow corridor low CAPE available just ahead
of the front. Forecast soundings show elevated convection could
develop during the evening hours. While instability is limited, due
to weak lapse rates, and elevated, shear in the elevated layer is
still rather strong. Forcing along the front, may be enough to
overcome the cap over the area though and given the strong shear in
the elevated layer, could lead to strong to severe storms late in
the evening. Overnight though, as cold air advances further south
and erodes the warmer air aloft, more widespread convection is
anticipated. Anomalously high precipitable water values, between 2
and 3 standard deviations above normal, may lead to areas of heavy
rain once convection is able to get going overnight. This old likely
be in the souther portions of the forecast area when this occurs.
The cold front responsible for this activity will stall to our south
and lead to several other chances for heavy rain and storms through
the remainder of the week. This looks mainly focused over the
southern portions of the forecast area and especially southern MO.
It`s not until the early part of next week, Sunday into Monday, that
the main upper trough moves east into the area. This looks like it
will bring widespread precipitation to the area early next week and
some potential for snow across northern MO as temperatures dip into
the mid 30s across the northern portions of the forecast area.
&&
.Aviation...(For the 00Z TAFS through 00Z Wednesday Evening)
Issued at 528 PM CST TUE MAR 9 2021
overnight wind and low level wind shear forecast will be
difficult. Going forecast kept wind gusts pretty high for
overnight standards, and there isn`t much disagreement with the
new forecast, as the low level atmosphere looks to be plenty gusty
overnight. Model guidance also suggest gusts will maintain
through the night. However, should the surface winds come down to
around 10 kts or lower the 50+ kt jet just off the surface will
become quite problematic for wind shear concerns. Made only minor
tweaks to the forecast for this run, but after monitoring the
early to mid evening trends may need to make some wholesale
changes to the forecast overnight.
&&
.Fire Weather...
Issued at 358 AM CST TUE MAR 9 2021
Strong southerly winds are expected both today and Wednesday. With
strong moisture return today, the relatively humidity values are
only expected to fall to 40-45 percent this afternoon. Winds are
expected to remain brisk through the overnight hours tonight, and
becoming increasingly gusty on Wednesday during the day gusting to
near 35-40 knots. Low lying stratus that is expected to develop
Tuesday night into Wednesday morning may lead to light
rainfall/drizzle, though the precipitation is not expected to amount
to more than a few hundredths of an inch till Wednesday evening. The
strong winds both days will lead to a high-very high fire danger.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...Wind Advisory from 7 AM to 5 PM CST Wednesday for KSZ025-057-060-
102>105.
MO...Wind Advisory from 7 AM to 5 PM CST Wednesday for MOZ001>006-
011>015-020>023-028>031-037>039-043>045-053-054.
&&
$$
Discussion...CDB
Aviation...Leighton
Fire Weather...BT
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
620 PM CST Tue Mar 9 2021
.SHORT TERM...(This evening through Wednesday night)
Issued at 226 PM CST Tue Mar 9 2021
As often happens with record breaking temperatures, we`ll see big
changes in the weather in the upcoming 24 to 36 hours as much colder
air (and snow) work into the area. The main forecast concerns are the
potential for accumulating snow late Wednesday and Wednesday night,
and the small chance for thunderstorms and severe weather over the
southeast portion of the area Wednesday afternoon/early evening.
Temperatures have warmed nicely today, although the warming has been
delayed along the I-35 corridor where a thick patch of clouds was
present through around noon. Warmer temperatures are apparent west
and east of that corridor at the current time, with mostly sunny
skies under a canopy of cirrus. Temperatures should manage to inch up
a bit more through around 4 PM before cooling off, then the upstream
cold front will move through most of the area tonight. The front
will stall late tonight from around Albert Lea through Eau Claire,
and a developing surface low will move northeast along that
baroclinic zone on Wednesday. There remains some disagreement with
where exactly the low will track, which hinges on how far the front
makes it tonight and how much the surface low intensifies Wednesday
(with the stronger solutions being farther north/west). Its position
will help determine where the axis of heaviest snow will be in the
west/north portion of the area late Wednesday afternoon into
Wednesday night. Didn`t change the going forecast too much in that
regard, with plowable snow still in the forecast from west central
into central Minnesota. Subsequent forecasts should be able to better
pin down location and amounts, with a winter weather advisory likely
forthcoming later tonight for a portion of the area. Across the
southeast part of the forecast area, thunderstorms will be a concern
Wednesday into early Wednesday evening, and the surface low track
will play a role in their location as well as whether or not any
severe weather occurs. There is some possibility that we`ll see a
pocket of instability (with MLCAPE AOA 500 J/kg) work into the
southeast portion of the area Wednesday afternoon into early evening.
Forecast hodographs are impressive, with low-level (0-1 km) SRH in
excess of 300 m^2/s^2. However, there is significant uncertainty with
this forecast, so it will simply need to be watched tonight into
Wednesday. The southeast portion of the area would be favored from a
synoptic perspective given the forecast track of the surface low from
the RAP and NAM, but boundary layer temperatures will dictate whether
or not convection will be rooted there and able to take advantage of
the strong shear which is forecast. If it`s able to do so, then some
isolated severe weather would be possible (damaging wind gusts and an
isolated tornado from any low topped supercell that`s able to form in
such an environment). At this point it appears to be a low
probability potential, but will bear watching. The system will move
northeast Wednesday night, taking precipitation with it, and most of
the area should be precipitation-free by Thursday morning.
.LONG TERM...(Thursday through Tuesday)
Issued at 226 PM CST Tue Mar 9 2021
As we pick up the extended portion of the forecast, the Low Pressure
system is on the way out of the area over the northern Great Lakes,
and as it continues to move eastwards we will see broad high
pressure begin to move in behind it. This broad area of high pressure
will ride the northern edge of an upper level jet, pushing towards
the Great Lakes and out of the area by the middle of Sunday, as a
broad trough swings northeastwards from the central Rockies.
As this trough continues to move and strengthen, a broad surface low
will develop and affect the central and northern plains beginning
late Sunday and continuing into Monday before diminishing. Right now
the trajectory of the trough would keep the center of the low fairly
far to the south in southern Iowa to northern Missouri, which would
keep most of the sensible weather down that direction as well. GEFS
ensemble members have a QPF range of anywhere from about an inch to
nothing at all, with an average of around 3 or 4 tenths of an inch.
This will of course change going forward as we clue in on the track
of the system and the overall amount of moisture available. There is
also the question of precipitation type, and for now that remains
just as much an uncertainty given the unknown track. Temperature wise
it looks like we remain above freezing, but only just on Monday
morning, so overall scenario right now would be rain for most, with a
chance for a zone of mixed precipitation trending towards snow on
the northernmost portions of the area. More details should become
available as we get a bit closer, especially once we resolve the
system moving through the short term period.
Otherwise, with a couple slow meandering systems, we shouldn`t
expect any major shakeups over the rest of the period in terms of
sensible weather. Most days will see a mix of clouds and sun with
temperatures in the low to mid 40s for highs and low to mid 30s for
lows which climate wise would be just a bit below normal, as
highlighted in the 6-10 and 8-14 day Climate Prediction Center
outlooks.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 619 PM CST Tue Mar 9 2021
VFR conditions will persists into the overnight hours, but ceilings
drop to MVFR tomorrow morning and eventually to IFR as widespread
rain spreads north across the region. Some breaks in the rain are
possible during the afternoon, but generally expect an extended
period of IFR ceilings and visibility from the late morning into the
late afternoon. Isolated thunder is possible across eastern
Minnesota and western Wisconsin so have included a prob30 mention for
now, but confidence is low overall for the thunder risk at any
particular site. The rain is expected to changeover to snow at AXN by
late afternoon tomorrow, but will hold off until the end of the
period at other central MN sites.
KMSP...Fairly high confidence on the arrival time of precipitation
tomorrow morning, but still unwritten on how long rain will fall
during the morning and afternoon. Expect IFR visibility during the rainfall with ceilings also dropping
to IFR during the late morning. A few breaks are expected at times,
but should fill back in fairly quickly. An isolated rumble or two of
thunder can not be ruled out as well, but overall chances look low.
Rain could change over to light snow late Wednesday night as the
precipitation diminishes, but little or no accumulation is expected.
/OUTLOOK FOR KMSP/
Thursday...MVFR early, becoming VFR. NW wind 5-15 kts becoming W.
Friday...VFR. NW wind around 5 kts.
Saturday...VFR. W wind 5-10 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
&&
$$
SHORT TERM...
LONG TERM...TDH
AVIATION...ETA
Area Forecast Discussion
National Weather Service Marquette MI
651 PM EST Tue Mar 9 2021
.SHORT TERM...(This evening through Wednesday)
Issued at 520 PM EST TUE MAR 9 2021
Mostly sunny skies and warm southerly winds allowed temperatures to
warm to 60F at several sites across the western U.P. this afternoon.
Warm southerly winds continue overnight ahead of an approaching
negatively tilted shortwave that is the main feature of interest in
the short term.
Southerly winds continue overnight ahead of a weak cold front
dropping south across the area Wednesday morning. The pre-frontal
air mass will be characterized by dew point temperatures well above
freezing, which is likely to produce fog over existing snow cover.
Additional lift provided by the passing cold front could produce a
brief period of dense fog. A moist post-frontal air mass will likely
prolong fog for areas favored by northerly upslope flow.
Synoptic scale lift increases on Wednesday as the negatively tilted
shortwave accelerates to the northeast resulting in a deepening sub-
1000mb low tracking across the CWA. Isentropic lift combined with
mid-level frontogenesis results in a swath of generally 0.50-1.00
inches of QPF that is expected to fall primarily as rain. However,
the lowest layer of the atmosphere is marginally cold enough for
precipitation type problems across higher elevations of the western
CWA. Raw model guidance (except the ECMWF) produces up to 3/4" of
QPF with surface temperatures below freezing indicating potential
for substantial ice accretion. However, warm antecedent
temperatures, a deep warm nose aloft, marginally cold boundary layer
temperatures, and potential for heavy precipitation rates suggests
relatively slow ice accretion rates. Colder air arriving late
Wednesday night will allow precipitation to change over to snow with
up to 2 inches expected by Thursday morning.
It`s worth mentioning that recent HRRR and NAM-nest model guidance
has enough elevated instability to support an isolated clap of
thunder, but did not include it in the grids at this time. If
thunderstorms do develop Wednesday afternoon and evening then more
substantial hydro hazards may occur. However, current expectations
are for localized ponding on area roadways.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 403 PM EST TUE MAR 9 2021
Long term period this shift will begin at 12z Thursday. At this
point the earlier mentioned surface low should over central Lake
Superior with the 700mb low over the Arrowhead with stout fgen
maximum/deformation zone extending into Ontario. Across western Lake
Superior, winds should become northwest, allowing for some moisture
with upslope enhancement into the Keweenaw to be possible into the
early afternoon. Initially a wintry mix will transition to snow as
the low lifts out and the cold air sufficiently cools the column. In
the central and east, any lingering precip in the morning would
likely be rain. Mid-upper level ridging will build in behind the
departing system allowing subsidence to eventually take over and
help clear out the skies by evening. Thursday highs should top out
in the upper 30s in the west and low 40s east. Overnight lows look
to be in the upper teens in the interior west half and 20s in the
east and by the lakeshores.
A shortwave looks to drop southeast through Lake Superior beginning
early on Friday. Strong CAA will help send 850mb temps down to
around -15 to -18C. Increasing low level lapse rates and sharp
pressure rises will allow for stronger winds aloft to mix down to
the surface. This will likely contribute to widespread westerly to
northwesterly breezy conditions. With stronger winds over eastern
Lake Superior, the northwest winds could build waves high enough to
create some lakeshore flooding east of Munising by evening. The
colder airmass will also result in more seasonable daytime highs in
the 30s with maybe some low 40s in Menominee County. With this front
being devoid of much moisture, the better precip chances look to be
on the north end of Lake Superior.
Little ambiguity is expected in the forecast across the region
through the weekend as a predominately dry air mass sits overhead.
With gradual warming at 850mb expected, daytime highs in the 30s on
Saturday will return back into the 40s west and south and upper 30s
north and east on Sunday. Through the weekend, an upper level low
will very slowly eject out of the central Rockies. The structure of
the feature is a little uncertain, but it appears to linger over the
Northern Plains on Monday. Guidance is suggesting some snow could
move into the region late in the day on Monday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 649 PM EST TUE MAR 9 2021
VFR conditions are expected to prevail for much of the night at
KIWD/KCMX/KSAW. In addition, low-level jet ahead of an approaching
cold front will also lead to LLWS. This LLWS will end from w to e
overnight into early Wed morning. Southerly flow advecting moisture
northward thru the night will bring MVFR cigs to all terminals prior
to daybreak with cigs lowering further to IFR by mid morning. Shra
will also spread quickly northward into the area during the morning.
During the aftn, IFR conditions will prevail at all terminals with
LIFR probably developing at KIWD/KSAW where an upslope wind
component will aid deteriorating conditions. There is a low
potential for -fzra at KIWD/KCMX late aftn as sfc temps may fall to
around 32F.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 429 PM EST TUE MAR 9 2021
Southerly winds will of 20-30 knots are expected over the central
and eastern parts of Lake Superior this afternoon and tonight. Some
gale force gusts to 35 knots can`t be ruled out, particularly for
higher reporting platforms. Winds will become light by Wednesday
morning and become northerly as the next system approaches from
the south. Northeast winds are expected to increase to gales over
the west as low pressure approaches and deepens over western WI.
The low should move through central Lake Superior during the
morning on Thursday, with winds becoming northwesterly lake-wide.
Some gale force gusts will be possible in the eastern part of the
lake by Thursday afternoon. A cold front will cross the lake on
Friday with a round of west to northwest gales possible.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
Gale Watch from Wednesday evening through late Wednesday night
for LSZ162-240>244-263-264.
Lake Michigan...
None.
&&
$$
SHORT TERM...EK
LONG TERM...JP
AVIATION...Rolfson
MARINE...JP