Area Forecast Discussion
Issued by NWS Marquette, MI

Home | Current Version | Previous Version | Text Only | 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 291914

Area Forecast Discussion
National Weather Service Marquette MI
314 PM EDT SUN MAY 29 2016

.SHORT TERM...(Today and tonight)
Issued at 412 AM EDT SUN MAY 29 2016

00Z raobs/latest wv imagery and rap analysis show shrtwv lifting
NEwd thru the Upr MS river valley. Lift associated with this
disturbance...pwats arnd 1.25 inch /150-200 pct of normal/ and axis
of a bit hier h7-5 lapse rates have triggered some showers/a few TS
over mainly wrn Upr MI closer to deeper moist air and away fm
relatively drier air shown on the 00z GRB raob. Overall though, weak
h85 theta-e advctn during period of nocturnal cooling and the
relatively dry 00z GRB raob have held down the coverage of the
showers. More isold-sct showers are present upstream fm SE MN into
NW WI in the area of DPVA ahead of shrtwv lifting to the NE. Looking
farther to the W, moist llvl air extends upstream into scentral
Canada/MN, but some drier air is present over NDakota.

Main fcst concerns this in the short term focus on expected
convection today/potential for some heavy ra.

Today...Shrtwv to the SW is progged to lift NE acrs the Western
Great Lks...reaching Ern Lk Sup by 00z Mon. Expect sct showers/a few
TS this mrng over mainly the wrn CWA to move to the E and become
more nmrs with the shrtwv forcing/accompanying sfc lo pres trof/axis
of deeper h85-5 mstr/daytime heating. Overall destabilization today
wl be limited by rather extensive cld cover and some morning fog...
with max temps topping out in the mid 70s away fm lk moderation. 00z
NAM fcst MUCape is about 1500 j/kg, but severe threat wl be limited
by 0-6km shear arnd 25 kts and deep moist lyr. The relatively weak
winds aloft/deep shear and hi pwats sug heavy ra wl be the main
threat from the stronger storms that dvlp.

Tngt...Any lingering showers/TS over mainly the ern CWA this evng wl
diminish with arrival of DNVA/Deep lyr qvector dvgc/mid lvl drying/
nocturnal cooling. The llvls are slower to dry out, but eventually
the steady WNW flow--with the 00z NAM showing h95-9 winds up to
30kts--is fcst to tap the drier air now moving E thru NDakota. The
arrival of this drier air should bring clrg to the W, but the ern
CWA wl probably remain mocldy thru 12z as the drier air is fcst to
remain to the W thru that time.

.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 18Z TAFS through 18Z Monday afternoon)
Issued at 150 PM EDT SUN MAY 29 2016

A cold front passing across the Upper Great Lakes will bring
improving conditions to all terminals during this fcst period. With
an upslope westerly wind, lowest conditions this aftn will be at
KIWD/KCMX where low mvfr cigs will likely prevail for at least the
next few hrs along with the possibility of -shra. Since flow is more
sharply upsloping at KCMX, there may be some ifr cigs at that
terminal. Early this evening, KIWD/KCMX should improve to VFR and
remain that way for the remainder of the fcst period. However, will
need to watch for lower clouds to linger longer at KCMX. At KSAW,
mostly vfr conditions are expected thru the fcst period, though
passing shra thru the area may lead to some mvfr conditions at times
until evening.

.MARINE...(For the 4 AM Lake Superior forecast issuance)
Issued at 412 AM EDT SUN MAY 29 2016

A relatively weak pres gradient/hi stability will dominate the Upper
Great Lakes most of this forecast period, so expect winds at or
below 20kts over most of the Lake. The one exception will be over
far western Lake Superior late Mon night into Tue, when the pres
gradient will tighten ahead of an approaching lo pres and terrain
funneling of the expected NE wind will cause winds up to 25 kts.
With moist air lingering over the chilly lake waters, dense fog will
persist most of today before the arrival of drier air from the W
begins to diminish gradually the intensity of the fog this afternoon
into tonight. Continued going Dense Fog Advisorys.

Upper Michigan...
Lake Superior...
  Dense Fog Advisory until midnight EDT tonight for LSZ243>246-

  Dense Fog Advisory until 4 PM EDT /3 PM CDT/ this afternoon for

  Dense Fog Advisory until 6 PM EDT this evening for LSZ263.

Lake Michigan...
  Dense Fog Advisory until 5 PM EDT this afternoon for LMZ248-250.



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