Area Forecast Discussion

FXUS63 KMQT 190852

Area Forecast Discussion
National Weather Service Marquette MI
452 AM EDT Mon Mar 19 2018

.SHORT TERM...(Today and tonight)
Issued at 451 AM EDT MON MAR 19 2018

WV imagery and RAP analysis indicated confluent mid/upper level flow 
through nrn Ontario into the nrn Great Lakes between a trough from 
Quebec into nrn New England and a ridge from IA into the ern 
Dakotas. This supported a building sfc ridge from nrn Manitoba into 
the Great Lakes which was bringing cool dry air into Upper Michigan 
on ene low level winds. Otherwise, IR loop showed an area of mid 
clouds spreading from ne MN into portions of north and western Upper 

Today, ne flow CAA will drop 850 mb temps to around -12C and keep 
temps below normal with highs from the  mid and upper 20s north to 
the lower 30s south. min temps at the top of the shallow cold layer 
to 3k ft will provide only marginal instability for any LES. The 
very dry low level air with dewpoints around 10F will also be 
unfavorable for any diurnal -shsn development. 

Tonight, although the slowly veering ne winds will be light enough 
to allow decent radiational cooling, there may be enough cloud 
cover to keep temps from dropping off too far. Nevertheless, 
expect min readings will still drop a bit below guidance from 5 to
10 inland to 10 to 15 near the Great Lakes. The dry air will 
remain unfavorable for any pcpn beyond a few flurries that may 
develop north central in upslope flow.

.LONG TERM...(Tuesday through Sunday)
Issued at 244 AM EDT MON MAR 19 2018

Looks like quiet weather will persist through much of the week. A 
weak upper level trough will bring an increase in mid-level clouds 
Tue into Wed but low-level dry air in a ne flow circulating around a 
Hudson Bay high should ensure dry conditions. The mid level clouds 
combined with the cool ne flow off Lake Superior will keep temps blo 
normal Tue into Wed with highs in the upper 20s north to lower to 
mid 30s south.  

Upper ridge from the west begins to shift into the Upper Great Lakes 
Thursday and Friday yielding more sunshine as temps push back toward 
normal with highs in the lower to mid 30s north to upper 30s south. 

Next weekend mainly on Saturday, the 00Z Canadian model indicates 
pcpn (mainly in the form of snow) reaching into mainly the sw and 
south central portions of Upper Mi, associated with a stronger 
shortwave moving through the Upper MS Valley. It is likely that the 
northern portion of the pcpn shield from this shortwave will be 
impeded by continued dry east to northeast low level flow from the 
Hudson Bay high as suggested by the drier 12Z/00Z ECMWF solutions 
and now the latest 00z GFS solution. At this point, will keep low 
chc pops in for light snow over the sw and south central fcst area 
based on model consensus, but could easily see drier solution of 
12Z/00Z ECMWF and 00z GFS verifying given strength of persistent 
ridging from Hudson Bay into the Upper Great Lakes.

.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 138 AM EDT MON MAR 19 2018

VFR conditions are expected through the TAF period.

.MARINE...(For the 4 AM Lake Superior forecast issuance)
Issued at 451 AM EDT MON MAR 19 2018

High pressure building in from Ontario will produce ne winds around 
25 knots over western Lake Superior today into tonight. Otherwise
no significant winds are expected through the forecast period, 
with winds generally staying at or below 20 knots. 

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