Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 02/11/24
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
612 PM EST Sat Feb 10 2024
.KEY MESSAGES...
- Dry weather pattern to prevail into early next week.
- A storm system will likely bypass the region to the south
Monday into Monday night.
- Colder temperatures closer to average take hold next week.
&&
.AVIATION...
Recent AMDAR soundings across srn Mi indicate the MVFR stratus is
located under a deep inversion. The moisture depth is also a little
higher than suggested by most model solutions. The RAP seems the
more reasonable model solution in its current handling of the low
clouds. The solution is fairly bullish with these low clouds through
tonight and into the day Sunday. The low level flow does get fairly
divergent, especially across metro Detroit after 06Z. This may allow
some breaks in the clouds to develop. The RAP does indicate this to
a degree with some late night breaks with redevelopment of the low
clouds later in the morning. Given that little overall change in the
inversion depth is expected tonight, a more pessimistic cloud
forecast will be carried into Sun afternoon, essentially prevailing
MVFR. A weaken of the gradient as sfc high pressure nudges in from
the west tonight will allow a steady drop in sfc wind speeds this
evening.
.DTW THRESHOLD PROBABILITIES...
* High in ceilings aob 5000 feet through this evening.
&&
.PREV DISCUSSION...
Issued at 306 PM EST Sat Feb 10 2024
DISCUSSION...
Confluent upper level flow will continue (and intensify) into early
next week as southwesterly subtropical plume around strong southern
stream shortwave south of the four corners region impinges on a more
westerly (but wavy) upper flow becoming established around the base
of upper level troughing in the northern stream throughout eastern
Canada. Surface high pressure ridging will expand eastward into the
area in response to this upper pattern with dry weather persisting
over the next several days. Temperatures will remain notably cooler
than the 50s to lower 60s that graced lower Michigan late this past
week with highs generally ranging in the upper 30s to lower 40s. As
high pressure becomes more prominent, expect more in the way of sun
area-wide as well.
The biggest potential weather maker for this forecast period will be
that large southern stream shortwave now over the southwest CONUS.
At this time, a plethora of model solutions strongly suggest this
system will remain south of the region as is ejects on a shallow
trajectory from the southwest CONUS and southern plains into the
Tennessee and Ohio valley regions Monday into Monday night. Such a
track would keep even the northern periphery of precipitation (snow
in this case) safely south of the Michigan and Ohio state line.
A somewhat complicated configuration of shortwaves from the Gulf of
Alaska east into the Yukon and also south through the far eastern
Pacific ocean to the Pacific Northwest coast cloudy the forecast
track of this system ever so slightly as the eventual northern
stream wave that digs southeast through western Canada into the far
northern Mississippi Valley from this mess will impact the steering
of this southern system as it makes its closest approach to the
region. In fact, eventual phasing of these features is forecast
throughout the model space, just well east of the region from New
England into Newfoundland. At this time, it appears this northern
wave will be subdued enough to allow this storm system to remain on
this more southern track around the base of the eastern Canadian
upper trough as it exerts the main influence on steering currents.
In the extended period from mid-late next week, this cooler upper
level pattern persists as additional northern stream shortwave
energy sweeps into the area and maintains temperatures in the 30s to
around 40. Precipitation chances (mainly snow) increase from this
system by around Thursday, but with some flurry/sprinkle chances
scattered throughout the later half of next week. In the wake of
this larger system, notably colder air begins to seep southeast into
the Great Lakes from late week on into next weekend. With this in
mind, expect highs to settle closer to 30 with time by the end of
this 7 day forecast and just beyond.
MARINE...
High pressure expands into the Great Lakes through the weekend,
maintaining light westerly flow through Monday and dry weather for
the nearshore and adjacent Lake Huron open waters. The northern half
of Lake Huron maintains sporadic coverage of snow showers owing to
slow departure of the Hudson Bay low through the weekend. A strong
low pressure system tracks across the Ohio Valley Monday-Tuesday,
with the broader local impact being a uniform shift to northwest
flow and localized, low (<20%) precipitation chances for western
Lake Erie. A trailing northern stream clipper draws lake enhanced
snow potential into the southern open and nearshore waters Tuesday.
There will be a brief return of high pressure mid-week before low
pressure and its attendant cold front arrive late this week which
will be the best opportunity for headline-worthy marine conditions
during the forecast period.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...None.
Lake St Clair...None.
Michigan waters of Lake Erie...None.
&&
$$
AVIATION.....SC
DISCUSSION...DG
MARINE.......MV
You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.
Area Forecast Discussion
National Weather Service Green Bay WI
541 PM CST Sat Feb 10 2024
Updated aviation portion for 00Z TAF issuance
.KEY MESSAGES...
- Quiet and seasonably mild weather will continue into the middle
of the upcoming week.
- Chances for light lake effect snow in northern Wisconsin
throughout the week. No major impacts are expected.
&&
.DISCUSSION...
Issued at 241 PM CST Sat Feb 10 2024
Short Term...Tonight and Sunday
The latest RAP analysis and satellite/radar imagery show Wisconsin
positioned between high pressure over the northern Plains and low
pressure over far northern Quebec. Northwest winds continue to
advect in a cooler airmass as well as cloud cover. 12z and amdar
soundings depict a shallow moist layer and therefore expect the
trend of eroding cloud cover to erode from south to north through
the rest of the afternoon. However, there is widespread low clouds
upstream and within the surface high. As the high drifts southeast
towards the western Great Lakes, forecast challenges mainly
revolve around cloud cover and temperatures.
High pressure will slide southeast from the northern Plains to the
mid-Mississippi Valley over the next 24 hours. Thermal profiles
modify slightly, but winds will remain out of the northwest or
west-northwest, with some indications of stratus returning into
north-central Wisconsin around midnight and continuing to spread
southeast. Without low level cold advection, have doubts that this
cloud cover will reach into northeast WI due to downsloping. But
additional cloud cover will also arrive late tonight into Saturday
morning ahead of a digging shortwave trough. Given the track of
the surface high, it`s possible that winds bounce in and out of
being calm. Combined with cloud cover, trended slightly warmer
than the previous forecast for low temps.
Sharp shortwave energy will track across the region on Sunday.
Moisture is severely lacking below 12000 ft, so no chance of any
precip. But will see cloud cover for the morning which should give
way to increasing sunshine in the afternoon. High temperatures
will be similar to today`s readings in the low to mid 30s.
Long Term...Sunday Night Through Saturday
The El Nino pattern of the last couple of weeks is
forecast to break down by the end of this week, as an upper ridge
builds along the West Coast and a Polar low moves south towards
the eastern half of the Lower 48s states. The first round of much
colder air looks to arrive next Sunday night as a 1035mb surface
high moves into the Northern Plains and Front Range. The GFS and
ECMWF suggest that a synoptic scale storm could bring snow to our
region Monday or Tuesday followed by another round of colder air
during the middle part of next week.
Some lake effect snow showers are possible in far northern Wisconsin
this week, but significant snow is unlikely. A front moving through
Thursday could bring some snow or rain showers. Temperatures will
remain around ten degrees above normal through the end of the work
week, with closer to normal temperatures next weekend.
&&
.AVIATION...for 00Z TAF Issuance
Issued at 534 PM CST Sat Feb 10 2024
Started off with the idea that stratus would continue to erode
from south to north this evening, but satellite trends suggest the
opposite. Have now decided to keep low clouds in place (and fill
in over C WI and the southern Fox Valley) through the night and
Sunday morning, with ceilings varying from 2000-2500 ft agl
northwest to 3000-3500 ft agl southeast. Don`t expect any
appreciable clearing to occur until subsidence in the wake of
short-wave trough overspreads the region Sunday afternoon. Light
to moderate W-NW winds will prevail through the TAF period.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION.....MPC/RDM
AVIATION.......Kieckbusch