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 270836

Area Forecast Discussion
National Weather Service Marquette MI
436 AM EDT Thu Apr 27 2017

.SHORT TERM...(This evening through Thursday)
Issued at 431 PM EDT WED APR 26 2017

WV imagery and RAP analysis indicated a mid/upper level trough from
the eastern Dakotas through Oklahoma resulting in ssw flow through
the wrn Great Lakes. One of several shortwave troughs lifting
through Upper Michigan supported an area of light to moderate rain
through the nrn cwa. There was a lull in the pcpn upstream over WI
with mainly patchy light rain or drizzle. The next main upstream
shrtwv was moving into sw Missouri. At the surface, 994 mb low
pressure was located over ne WI with a trough extending to the ne
through centrl Upper Michigan into se Lake Superior. Much colder air
prevailed behind the trough over the nw cwa with temps in the mid
30s while temps had climbed into the lower to mid 50s over the
south and east.

The short range models have trended slightly to the west with the
area of heavier pcpn associated with the shrtwv lifting into the
area as the sfc low moves through Lake Michigan. Expect the
heavier band of pcpn mainly btwn 09z-15z. Additional QPF in the
0.25-0.50 inch range will be likely over much of the area from
late tonight through Thursday morning.

Temps should climb slightly this evening central as the low lifts to
the northeast but should fall off by late evening as low level caa
increases behind the low. Although there is still some uncertainty
with  where the strongest temp gradient will set up, there is a high
enough probability that temps will be at or below freezing over the
higher terrain of the west by late tonight. to expand the winter
weather advisory into wrn portions of Marquette county. Similar to
today, the strongest icing is likely on trees and power lines as the
ground remains warm enough to minimize icing on the roads. Overall
ice amounts could still approachin a quarter inch in some locations.
A changeover to snow and sleet is also expected over the west third
as the warm layer aloft shrinks and dissipates.

.LONG TERM...(Friday through Wednesday)
Issued at 436 AM EDT THU APR 27 2017

Nam shows a closed 500 mb low between Hudson Bay and Lake Superior
12z Fri with another closed low in the central Rockies and another
in the Canadian Rockies. The closed low over the central Rockies
opens up and becomes an elongated trough on Fri. The southern end of
the trough becomes a closed low over the 4 corners region 06z Sat
and this closed low heads east into KS 12z Sun. Cannot believe that
there will be some lake effect pcpn, but there will be for the
Keweenaw Peninsula on Fri as 850 mb temperatures are down to -8C and
with Lake Superior temperatures around 4C, that is enough for lake
effect even at this time of year. Should be some disruption of it
though during the day with strong heating, but did put in chance
pops for westerly flow areas. More lake effect is possible for Fri
night into Sat morning and have some slight chance pops in for
northwest flow as temperatures again are cold enough. These are the
only major changes made to the going forecast made. Could be some
freezing rain early Fri morning in the Keweenaw and in parts of the
north central Fri night.

In the extended, GFS and ECMWF show a 500 mb closed low and trough
over the central plains 12z Sun that heads north into ne IA 12z Mon.
The upper low continues to the northeast to near James Bay 12z Tue
with colder air aloft over the area then. More upper troughing moves
into the area 12z Wed and remains into Thu. Temperatures will
continue to be below normal through this forecast period. Next
system comes in for Sun into Tue and there looks like there could be
a rain/snow mix with this one and could also be heavy precipitation
with this. Dry weather is then expected Wednesday into Thursday.

.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1240 AM EDT THU APR 27 2017

A sfc trof over Upper Michigan will result in poor conditions at
KIWD/KCMX/KSAW through this fcst period under periods of showers and
considerable low-level moisture in the vcnty of the trof. IWD/CMX
will be down to IFR with periods of LIFR tonight into Thu morning.
LIFR conditions should continue at SAW through tonight with some
improvement Thu morning as winds become nnw with a more downslope
component. Shallow cold air will filter into western Upper MI for
a change to -fzra at KIWD and KCMX tonight. Expect modest
improvement toward Thu evening at KIWD and KSAW as drier air from
the west allows cigs to improve to low end MVFR. KSAW will see
quicker improvement to MVFR late Thu afternoon/evening as winds
shift to westerly downslope direction.

.MARINE...(For the 4 AM Lake Superior forecast issuance)
Issued at 436 AM EDT THU APR 27 2017

Northeast gales to 45 knots continue over west and central Lake
Superior into this evening. By late tonight into Thursday morning
winds will begin to subside to 20 to 30 knots as winds become
northerly. Late Thursday through Friday, winds will further decrease
to 10 to 20 knots as winds become westerly. Winds of 10 to 20 knots
are expected through the weekend but could see much stronger winds
to at least 30 kts next Monday as strong low pressure system lifts
across the Great Lakes.

Upper Michigan...
  Winter Weather Advisory until 8 PM EDT /7 PM CDT/ this evening
     for MIZ001-003>005-010-084.

  Winter Weather Advisory until 1 PM EDT /noon CDT/ this afternoon
     for MIZ002-009.

Lake Superior...
Lake Michigan...


MARINE...07 is the U.S. government's official web portal to all federal, state and local government web resources and services.