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Area forecast discussion
National Weather Service Green Bay WI
624 am CDT Thu Aug 22 2019

Updated aviation portion for 12z taf issuance

Short Friday
issued at 323 am CDT Thu Aug 22 2019

Fairly quiet weather with minimal impacts expected through the short-
term portion of the forecast.

WV imagery shows a couple of shortwaves across southern Canada and
northern Minnesota this morning. Infrared imagery shows a widespread mid-cloud
deck spreading southeastward from northern Minnesota and northwest Wisconsin into
central and northeast WI this morning. Radar trends continue to show
the main precipitation area well south of WI, across the mid-
Mississippi Valley into the Ohio River valley. A few radar returns
were also showing up off the Dryden, on (xdr) Canadian radar. Some
light precipitation was also being observed under these returns.

A fairly dry surface ridge will become centered across the area
through this time period. Aloft, a fairly deep trough axis across
the area this morning, will steadily shift east tonight. Friday,
upper-level ridging will begin building into the area from west to
east. A period of mostly cloudy skies can be expected through this
afternoon as a shortwave rounds the base of the aforementioned
trough. There may be just enough moisture and weak instability to
touch off some isolated afternoon showers or sprinkles. (This is
also supported with the light precip detected in Canada this
morning) the best chance of this will likely remain near the Upper
Michigan border, where a little better moisture is present in the
layer. Again, enough low-level dry air in place will likely limit
coverage and keep any showers/sprinkles fairly light. As the surface
high becomes centered overhead tonight, expected skies to clear and
winds to become light and variable. The combination of the two, will
likely lead to some patchy fog development across central into north-
central WI. It is also possible that some patchy frost could develop
right along the u.P. Border by early Friday morning. Friday looks to
be a very quiet weather day with calm winds and mostly sunny skies
across the area. High temperatures today will likely struggle to get
out of the 60s for most locations before warming into the mid 60s to
low 70s for Friday. Overnight lows are expected to be chilly, with
most locations dropping down into the 40s, the exception will be
across the North Woods where some locations may see lows drop into
the mid to upper 30s.

Long term...Friday night through Wednesday
issued at 323 am CDT Thu Aug 22 2019

A gradual warming trend is expected into early next week in
southerly surface flow between a departing surface high and
approaching low. Temperatures will still be near or below normal
each day. Light winds aloft should increase from the southwest by
early next week and a short wave, combined with the approaching
surface low, will bring chances for showers and storms to the
area late Sunday night through about sunrise Tuesday morning.
Cyclonic flow at the surface and aloft will persist through at
least the middle of next week, so there may be some showers and
thunderstorms at times through Wednesday, especially during the
afternoon hours.

Aviation...for 12z taf issuance
issued at 624 am CDT Thu Aug 22 2019

Great flying conditions will continue at each taf site through
much of the rest of the week. An upper-level disturbance will
slide across northeast Wisconsin today, leading to a steady
increase in cloud cover with ceilings around 6000 to 8000 ft
through this afternoon. There could also be a few sprinkles or
light rain showers this afternoon, but no visibility restrictions
are expected from these. Tonight into early Friday morning, some
shallow fog may form near the rhi taf site, briefly reducing
visibility to MVFR at times. &&

Grb watches/warnings/advisories...


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