Area Forecast Discussion
Issued by NWS Marquette, MI

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
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 260845

Area Forecast Discussion
National Weather Service Marquette MI
445 AM EDT THU MAY 26 2016

.SHORT TERM...(Today and tonight)
Issued at 444 AM EDT THU MAY 26 2016

A couple (more) shortwaves will bring convection to the area this
afternoon/evening and then moving in late tonight.

Early morning rain will continue to exit the area over the next few
hours and fog will dissipate this morning over land.

Big question for today is the extent/coverage/intensity of
afternoon/evening convection as the shortwave (currently over NE)
moves through. Most models show some convection over the area today,
but models that show the least intense convection do not adequately
show the line of convection over IA and SE MN, so leaned more on
models that are better representing that. Good timing of the
shortwave to intercept peak heating. Have max temps up to 80 F over
the interior north central and west, and up to the mid 80s near the
WI border. Reasonable expectation for MLCAPEs today are around 1,500
J/kg, although the NAM has over 2,500 J/kg (appears to be too moist,
which is a known bias) and the GFS has just over 1,000 J/kg. The
1,500 J/kg was based on adjusted NAM soundings, the SREF mean and
UCAR ensemble. Low level winds will be on the light side, but with
40-45 kt westerlies, 0-6 km effective shear will be 40-50 kts.
Hodographs are favorably oriented for storm organization in a hockey
stick shape. With lake breezes developing today, most concern is
over the central (mainly north central) where E moving storms may
become pinned to the lake breeze boundary and become right deviant
as they follow the boundary to the SE. If this occurs, any right
movers will see enhanced inflow and shear, and could produce a
tornado or two. Confidence in the tornado threat is very limited and
the circumstances are quite conditional, but it can`t be ruled out.
Isolated large hail and damaging wind threat is a greater potential.
Will include wind/hail threat in the HWO/EHWO, lower confidence of
tornado threat will exclude that from being mentioned.

Additional, non-severe convection will approach or move into areas
near the WI border late tonight as another shortwave approaches.

.LONG TERM...(Thursday night through Wednesday)
Issued at 444 PM EDT WED MAY 25 2016

Periods of showers and some thunderstorms with temperatures running
slightly above average through the holiday weekend.

Quite a mess of a forecast into next week. Broad troughing across
the western U.S. will send several waves of energy NE across the
Plains around broad ridging across the eastern U.S. Timing of
shortwaves/WAA/jets vary among the models, so pinpointing exact
times of precip is nearly impossible. With ample low-level moisture
and some daytime heating, any piece of energy will be able to force
at least some shower/storm activity.

An axis on the eastern ridge will bring mostly dry conditions to the
CWA Thursday night into Friday morning, though a few stray showers
cannot be ruled out. By the afternoon, a subtle mid-level shortwave
and weakly coupled upper jet pattern will induce a shield of showers
and thunderstorms that will spread NNE across the Upper MS Valley
and western Great Lakes. At this time, the precip should move in by
the afternoon hours, thus limiting the amount of destabilization.
However, if the energy arrives later in the afternoon, increased
destabilization combined with 25-35kts of 1-6km shear will be enough
to produce some strong storms.

Continued moisture advection with ripples of energy moving northward
from the western trough will result in periods of showers and some
thunderstorms Friday through much of the day Saturday. It is
possible that some locations across mainly the west could see as
much as two inches of rain during this period.

By Sunday, the pattern transitions to a more zonal look. Chances for
showers and storms will continue during this transition on Sunday
before mostly dry conditions are expected late Memorial Day into
Tuesday as weak upper ridging moves across the Upper MS Valley and
Great Lakes region. Another more potent trough is then progged to
bring showers and storms for Wednesday.

.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 132 AM EDT THU MAY 26 2016

Area of rain showers over the area will continue to move northeast
the rest of tonight. Thunderstorms have been isolated at best so
left those out of the TAFs. Conditions will eventually lowering to
lifr/vlifr at all sites. Expect conditions to gradually improve Thu
morning reaching VFR by Thu afternoon at all sites.

.MARINE...(For the 4 AM Lake Superior forecast issuance)
Issued at 444 AM EDT THU MAY 26 2016

Expect winds at or below 20 knots through the forecast period. Fog
will continue to be a problem at times and will be dependent on the
rain that falls.

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


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