National Weather Service Raw Text Product

665 
FXUS63 KMQT 161738
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
1238 PM EST Wed Jan 16 2019

.SHORT TERM...(Today and tonight)
Issued at 445 AM EST WED JAN 16 2019

Water vapor imagery and RAP analysis shows a mid/upper level ridge 
from western Canada into Alaska with a downstream deep trough/vortex 
in the vicinity of Hudson Bay resulting in cyclonic wnw flow through 
the northern Great Lakes. Strong 700-300 qvector conv and subsidence 
has take over as the shortwave trough that pushed the arctic front 
through Upper Michigan has slipped to the east of the area. At the 
surface, a 1032 mb high located over Manitoba was building into 
the Upper Mississippi Valley and northern Great Lakes. NNW winds 
across Lake Superior and 850 mb temps around -20C supported mainly
light multiple wind parallel LES bands as upstream drying and 
acyc flow along with inversion heights of around 5k ft limited the
intensity. 

Today, as surface ridging builds into the area with inversion 
heights falling to 3-4kft and increasingly acyc flow, the LES should 
rapidly diminish to flurries by afternoon over most of Upper 
Michigan. However, the longer fetch into ne Upper Michigan will keep 
at least light LES going. Additional accumulations of an inch or two 
are possible, mainly from Alger county into northern Luce. Expect 
below average temps with highs in the teens.

Tonight, winds backing to the southwest will push the remaining LES 
mostly offshore but may brush the northwest Keweenaw Peninsula. Some 
clearing inland will allow temps to drop at or below 0F for typical 
cold spots. Otherwise, readings closer to 10 are expected near the 
Great Lakes.

.LONG TERM...(Thursday through Tuesday)
Issued at 308 AM EST WED JAN 16 2019

Upper air pattern consists of a 500 mb trough and closed low off the 
Pacific NW, a trough in the mid Mississippi valley and a broad 
trough across central and eastern Canada 12z Thu. The upper Great 
Lakes remains in an upper trough from 12z Thu through 12z Sat. Looks 
to be a prolonged lake effect snow event this forecast period with 
little change in the winds and temperatures which will stay below 
normal. Bumped pops up to the previous forecast as they were too low 
in superblend and added some qpf in as well as the models are 
underdoing the lake effect snow a bit. These were the major changes 
to the forecast made. 

In the extended, the GFS and ECMWF show a 500 mb deep trough in the 
southern plains 12z Sat with very cold air at 850 mb in Canada. A 
piece of this cold air moves into the upper Great Lakes 12z Sun as 
the 500 mb trough moves to the northeast into the ern U.S. with 850 
mb temperatures down to -28C across Lake Superior. The trough moves 
into New England 12z Mon with the coldest air to the east. A trough 
moves back into the northern plains 12z Tue and this moves into the 
upper Great Lakes on Wed. Below normal temperatures continue for 
this forecast with mostly lake effect snow as the only weather as 
storm systems stay well away from the area with cold air pouring 
across Lake Superior.
&&

.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1238 PM EST WED JAN 16 2019

Lingering lake effect snow showers will continue to dissipate and/or 
push offshore through this afternoon and early evening. As these 
showers dissipate, MVFR ceilings will scatter out. Broken mid to 
upper level clouds will filter in overnight into Thursday morning, 
with the potential for MVFR ceilings and snow showers to return 
towards the end of this TAF period. West to northwest winds will 
become light and variable as high pressure moves overhead, and then 
southerly Thursday morning.
&&

.MARINE...(For the 4 AM Lake Superior forecast issuance)
Issued at 445 AM EST WED JAN 16 2019

35-40 knot nnw gales will linger early this morning. Winds will then 
diminish quickly blo gales this morning as high pressure builds in 
quickly from the west. Winds will generally stay below 30 knots 
through the rest of the forecast period.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
  Heavy Freezing Spray Warning until 1 PM EST this afternoon for 
     LSZ242>245-248>251-263>267.

Lake Michigan...
None.
&&

$$

SHORT TERM...JLB
LONG TERM...07
AVIATION...Ritzman
MARINE...JLB