Area Forecast Discussion
Issued by NWS Marquette, MI

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

FXUS63 KMQT 251948

Area Forecast Discussion
National Weather Service Marquette MI
348 PM EDT Sun Jun 25 2017

.SHORT TERM...(This evening through Monday)
Issued at 348 PM EDT SUN JUN 25 2017

Soggy weather pattern continues through much of the short-term
forecast with heavy rainfall potential expected through late
tonight. There may also be some pea size hail late this afternoon
into early this evening thanks to lower freezing levels.

Tonight: The main focus for heavier rain showers and possibly an
evening thunderstorm will be a strengthening surface trough
continuing to linger across the area along with another strong
shortwave sliding through the area. The stronger shortwave moving
through will help to develop a closed low just southeast of the U.P.
late tonight into Monday morning. The combination of these features
along with ample deep layer moisture/forcing will lead to the
potential for some heavier rain to occur across inland portions of
the U.P. Continued wrap-around moisture and forcing will keep the
rain in the forecast through the overnight hours. This is something
that will need to be watched as many of the basins received an inch
or more of QPF over the past 18 hours; therefore, any heavier rain
that does occur will quickly turn to surface runoff into area
streams and rivers. The greatest threat for this occuring would be
along the WI border into portions of the inland west half of the
U.P. PWAT values are around an inch or more across most of the area
through much of tonight, which again points to heavier rainfall

Monday: The aforementioned shortwave is expected to move very slowly
across the area tonight, in fact, the models still have the
shortwave just south of the U.P. around 12Z Monday. The added upper
level support and surface trough lingering nearby will keep the
chances for rain showers in the forecast through most of the day
Monday.  Again, there may be some heavier rain that occurs with this
system as deep moisture and forcing lingers across the area.
Rainfall potential will be greatest over the east half throughout
the day; however, the west half will see the greatest chance in the
morning and then a very slow decrease in rainfall potential through
the afternoon hours. The additional cloud cover across the area will
help to keep temperatures in the 60s across the U.P. with the
warmest temperatures expected west, where the precip gradually
decreases throughout the day.

.LONG TERM...(Monday through Saturday)
Issued at 337 AM EDT SUN JUN 25 2017

Overall, there will be a brief warming and drying trend through the
early part of the week, before another system rolls across the Upper
Mississippi Valley and into the Great Lakes region late Wednesday
and Thursday. Depending on the track of this system moving across
the Great Lakes, we could see heavy rain move across Upper Michigan
that may lead to some hydro concerns. Still a bit early as model
trends continue to fluctuation from run to run, but the medium range
models are in good agreement with the placement of this heavy rain
across Upper Michigan late Wednesday afternoon into Thursday
morning. Towards the end of the week and into the weekend, we will
then see periodic chances for precipitation, with seasonable

On Monday, expect showers to linger across the central and eastern
portions of Upper Michigan as surface low pressure and its
associated upper-level wave are slow to exit the area. The lingering
cloud cover and precipitation should keep temperatures in the 60s yet
again. Locations across the west will see the warmest temperatures,
as they will have the best chance at seeing decreasing cloud cover
in the afternoon hours. Monday night into Tuesday, shortwave energy
will finally dig south across lower Michigan and into southern
Ontario, and surface high pressure will drop south from the northern
Plains. This will allow skies to clear and precipitation to come to
an end from west to east. Heights will rise a bit, but with flow
aloft still progged to be out of the northwest, a few subtle, weak
impulses will dig across the area and allow cloud cover to increase
through the day on Tuesday. Given the amount of dry mid-level air
advecting into the region as surface ridging slides off to our south
on Tuesday, expect much of the area to remain dry.

Wednesday through Thursday, a more potent shortwave will push east
across the Upper Mississippi Valley and Great Lakes regions with
medium range models showing the *potential* for a heavy rain event
across Upper Michigan. Ahead of this system PWATs will increase to
around 1.5 inches as strong warm air advection and 850-700mb
moisture transport lifts northeast towards Upper Michigan. The
medium range models, based off their 00z runs, are in good agreement
with a band of heavy rain developing along the surface warm front as
it lifts north across Wisconsin and into Upper Michigan late
Wednesday afternoon. Wednesday evening and overnight into Thursday,
as a 30-50 knot low-level jet impinges northward, this will sharpen
the mid-level front and allow the sloping baroclinic zone to deepen
to around 500mb. Large scale lift should also increase across the
area as a coupled jet structure develops aloft with shortwave energy
lifting northeast across Wisconsin and another shortwave digging
south across southeast Ontario. Given the antecedent wet conditions
across the area, with many locations over the past week and a half
picking up around 5-8+ inches of rainfall, if this band of heavy
rain does come to fruition across Upper Michigan it could lead to
hydro/flooding concerns. Model trends through this time period will
need to be monitored as a shift either north or south will have a
big impact on how things will play out.

Unfortunately it doesn`t look like this active pattern will release
its grip on the region as additional shortwaves are progged to track
across the area towards the end of the week and through the weekend.
This will bring additional chances for showers and perhaps a few
rumbles of thunder.

.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1259 PM EDT SUN JUN 25 2017

Ceilings and visibility has been improving at most of the TAF sites
this afternoon; however, IWD has steadily seen ceilings down in the
IFR to occassional LIFR range. This will continue to be the case at
IWD through the remainder of the TAF period as more rain showers
continue to spread into the area from the west. CMX and SAW will see
improved conditions until later this afternoon as the next batch of
rain showers and possibly a thunderstorm or two develops across the
area. Once the rain begins, it will continue, heavy at times through
much of the night. This area of heavier rain will likely be focused
across SAW, but its possible that CMX may also get some of the
heavier rain showers. Ceilings will drop as well with the
approaching disturbance, with upstream obs generally near 1kft or
less. Fog may also develop over the TAF sites at times, which may
reduce visibility below 5 miles at times tonight. This
disturbance will shift eastward Monday allowing for a gradual
improvement from west to east throughout the day.

.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 348 PM EDT SUN JUN 25 2017

Winds of 10 to 15 knots are expected to continue through the first
half of next week as the pressure gradient decreases and high
pressure builds in for the first part of the work week. Towards the
middle of the week, winds will start to increase to around 20 to 25
knots as a system lifts across the Upper Great Lakes. Winds will
then decrease to around or less than 15 knots towards the end of the
week and next weekend as the pressure gradient relaxes again.

Upper Michigan...
Lake Superior...
Lake Michigan...


LONG TERM...Ritzman
MARINE...KEC is the U.S. government's official web portal to all federal, state and local government web resources and services.