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 300806

Area Forecast Discussion
National Weather Service Marquette MI
406 AM EDT MON MAY 30 2016

.SHORT TERM...(Today and tonight)
Issued at 406 AM EDT MON MAY 30 2016

00Z raobs/latest wv imagery and RAP analysis show a weak shrtwv rdg
axis moving thru MN and toward Lk Sup in a zonal flow alf along the
Cndn border. Lingering clds in the wake of departing shrtwv
responsible for ydays showers/TS are just present over the ern CWA.
The 00Z INL raob is still rather moist blo mid lvl subsidence invrn
arnd h7, and there are some patchy SC/AC streaming into the wrn CWA
in the steady, slightly acyc llvl WNW flow ahead of a sfc rdg axis
in MN. The 00Z Bismarck raob shows much drier llvl air. Some patchy
fog has formed at some sheltered locations over the interior W where
winds are lighter in the presence of the lingering llvl mstr.
Looking upstream, there is another shrtwv moving E near Lk Winnipeg.
Farther to the W, a stronger shrtwv is moving E thru the nrn Rockies.

Main fcst concerns in the short term are cld trends early today and
then potential for some pcpn later tngt in advance of shrtwv moving
thru the nrn Rockies.

Today...Shrtwv rdg/Sfc hi pres/drier llvl air represented by the 00z
Bismarck raob are fcst to drift into the Upr Lks this Memorial Day.
Expect any lingering clds over the E and over the wrn CWA associated
with the moister INL raob to give way to just some diurnal cu inland
fm lk breezes. Some of the models also indicate a few showers that
form over nrn MN/adjoining Ontario on a fnt stalling acrs nrn Lk Sup
that is associated with shrtwv now near Lk Winnipeg may impact Isle
Royale later this aftn into early evng, but the llvls wl become too
dry for any pcpn over the rest of the CWA. With h85 temps fcst to
peak arnd 12C, expect hi temps to reach the mid/upr 70s away fm lk

Tonight...The 00Z NAM indicates the showers that form along stalling
fnt/axis of mid lvl fgen over nrn Lk Sup wl drift over wrn Upr MI
this evng, but prefer the pcpn-free models that hint at just some
mid clds given dryness of the llvls. Except for the NAM, the bulk of
the guidance is dry until very late, when the shrtwv now in the nrn
Rockies is progged to move into the nrn Plains. WAA/isentropic
ascent best shown on the 305K sfc /near h7/ is fcst to dvlp over the
wrn CWA late, and many of the models generate some pcpn in this area
in the 09z-12z Tue timeframe. So bumped up pops ove the wrn CWA fm
the previous fcst, which was completely dry except for far wrn Lk
Sup. With a faster incrs in cld cover, opted to raise fcst min temps
a bit, except over the E and SCentral, where skies wl be moclr

.LONG TERM...(Monday night through Sunday)
Issued at 314 PM EDT SUN MAY 29 2016

Nam forecasts a shortwave ridge moving into the upper Great Lakes
00z Tue with a trough moving into the northern plains. The trough
slowly moves east while the ridge remains over the upper Great Lakes
00z Wed. The trough then moves into the northern Mississippi River
valley 00z thu. Nam brings in some deeper moisture with the 850-500
mb q-vector convergence by Tue evening and keeps both around until
late Wed afternoon when the deeper moisture leaves the area. GFS and
ECMWF show about the same thing as the Nam does and will use a blend
of the models for this forecast.

Will keep Mon night dry and then bring in pops on Tue and have them
last through Wed with the next system moving in. Could see qpf
amounts of 0.67 inch to 1.00 inch of rain from Tue through Wed. Did
not make many changes to the going forecast overall for temperatures.

In the extended, GFS and ECMWF show a 500 mb trough over the upper
Great Lakes 12z Thu with a ridge in the desert sw. Upper air pattern
changes little for 12z Fri. On Sat, the 500 mb ridge builds in the
western U.S. with troughing in the ern U.S. and the pattern
continues to amplify for Sun. Temperatures will remain near normal
for this forecast period with unsettled weather at the beginning
part of the extended forecast into Thu night.

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 827 PM EDT SUN MAY 29 2016

Isolated showers ending this evening as frontal boundary moves east
of the area. With drying conditions behind the front, generally
expect vfr conditions through period at all taf sites, although may
need to watch for possible lingering low clouds at KCMX this evening
in upslope westerly flow.

.MARINE...(For the 4 AM Lake Superior forecast issuance)
Issued at 406 AM EDT MON MAY 30 2016

As steady W winds push drier air over Lake Superior today, expect
lingering fog to dissipate. Winds will become light this evening
with the arrival of a hi pres ridge, but as the pres gradient
tightens in advance of an approaching lo pres, ENE winds into Tue
will increase up to 25 kts over the far W, where terrain influences
accentuate this flow. As the approaching lo moves NE into Ontario on
Wed, winds will veer to the S but diminish as the pres gradient
tightens in the presence of hier stability. More widespread fog will
redevelop as the deeper S wind transports moister air over the still
chilly lake waters. After the low moves farther E and into Quebec on
Thu, winds will shift to the WNW and draw drier air back into the
area, dissipating the fog by late Thu. Lighter winds will return as
hi pres moves over the area on Fri.

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


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