Green Bay, Wisconsin 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

509
FXUS63 KGRB 150018
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
618 PM CST Thu Nov 14 2024

Updated aviation portion for 00Z TAF issuance

.KEY MESSAGES...

- Light rain and drizzle will taper off from southwest to
  northeast late this afternoon through mid-evening. Overcast
  conditions will persist into Friday morning.

- High temperatures will range from 5 to 10 degrees above normal
  through early next week.

- Next potentially impactful weather system is forecast to arrive
  on Monday night and Tuesday with widespread rain and breezy
  conditions. Wet and cool conditions are expected through the
  middle part of next week.

&&

.DISCUSSION...
Issued at 226 PM CST Thu Nov 14 2024

Short Term...Tonight and Friday

The latest RAP analysis and satellite/radar imagery show a broad
area of weak low pressure centered over far southern Lower
Michigan early this afternoon. An elongated upper trough extends
from the Ohio Valley to northeast Wisconsin and western Lake
Superior. Coverage of showers and drizzle has been steadily
diminishing over northeast WI. However, low stratus extends west
to the eastern Dakotas where moisture is trapped below an
inversion centered at 850-800mb. Clearing is occurring over the
central and western Dakotas west of a surface ridge axis. Focus of
the forecast revolves around precip and cloud trends.

Clouds and Precipitation: Chances of precipitation (light rain and
drizzle) will diminish over northeast Wisconsin late this
afternoon into early this evening as the upper trough and
associated mid- level moisture exits to the east. Saturation seems
rather robust below the inversion over Minnesota, so believe
erosion of the low overcast will be slow and likely not to occur
until Friday when clearing should occur from southwest to
northeast over the course of the day. Some breaks may occur at
times, but predictability of when and where is low.

Temperatures: Due to the cloud cover, went slightly warmer than
the NationalBlend for min temps tonight. No significant changes to
temps on Friday with highs in the upper 40s to middle 50s.

Long Term...Friday Night Through Thursday

Relatively low impact weather remains expected through early next
week.  Light rain chances along a cold front on Saturday night into
Sunday is one forecast concern.  But the primary concern will be
revolving around a cyclone due to impact the region starting on
Monday night.

Precipitation:  A reasonably potent low pressure system will be
tracking northeast from the northern Plains to northern Ontario on
Saturday and Sunday.  This low will push a cold front east and
across the state on Saturday night into early Sunday.  Precipitable
water values will be climbing upwards of 200% of normal along the
front despite the most impressive dynamics passing north of the
region.  Because of the dry air ahead of the system, forecast
soundings indicate trouble achieving deep saturation.  Probabilities
have increased for precipitation, but the saturation issues indicate
amounts will be light.  The chance of rain will exit early Sunday
morning.

In the wake of this system, attention then turns to dynamic energy
that will be lifting northeast from the southwest conus early next
week.  Models indicate this energy will be weakening as it moves
into the northern Mississippi Valley/western Great Lakes on Monday
and Monday night.  With dynamics and cold air mainly west of the
region, temperatures look sufficiently warm for precip to be rain.
Gusty winds and moderate rain look to be the main impacts from this
system through Tuesday.

A little too far out to get a handle on specifics thereafter.
Predictability in the pattern for the middle of next week is quite
low due to blocking occurring over eastern North America, split
flow over the west, and potential for phasing systems.

&&

.AVIATION...for 00Z TAF Issuance
Issued at 618 PM CST Thu Nov 14 2024

Lingering drizzle will slowly end across eastern WI this evening,
with dry conditions expected the rest of the TAF period. Plenty of
low-level moisture will keep mainly IFR/MVFR ceilings in place
tonight into at least Friday morning, with some lower visibilities
possible at times as well, especially if any breaks in the clouds
can develop. Then, as high pressure builds into the region, skies
will begin to clear out Friday afternoon and evening, but some
lower clouds could remain as surface low turns to the southeast.
Some higher clouds will also spread into the region later on
Friday. Winds will remain under 10 kts.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION.....MPC/MPC
AVIATION.......Bersch