NWS-Green Bay Forecast Discussion

 

						FXUS63 KGRB 190819
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
319 AM CDT Tue Mar 19 2019

Forecast discussion for routine morning forecast issuance

.SHORT TERM...Today...Tonight...and Wednesday
Issued at 319 AM CDT Tue Mar 19 2019

High clouds streamed in across the area early this morning as a
weak upper level trough tracked through the western Great Lakes
region. Clouds will decrease later this morning as the trough
slips off to the south, leaving mostly sunny skies. The clearing
will be short lived as another mid level PV anomaly plunges south
from Canada, bringing increased clouds from north to south during
late this afternoon and into the evening hours. High temperatures
are expected to rise into the 40s across the region.

The aforementioned PV anomaly will continue sinking south tonight,
bringing thickening clouds and the chance for snow across the
north late tonight. Given the increased clouds low temperatures
tonight will only fall into the upper 20s across the north, with
lower 30s across the south and east.

Precipitation chances will increase on Wednesday as a positively
tilted mid level trough digs through the western Great Lakes
region. Although QPF amounts from this system are fairly light,
the dynamics are quite impressive with the mid level shortwave and
pronounced trough. Daytime highs around 40 degrees will mean
precipitation type will mainly be in the form of rain for most of
the day, with any snow from the morning hours being light or
melting quickly once the sun comes up.

.LONG TERM...Wednesday Night Through Monday
Issued at 319 AM CDT Tue Mar 19 2019

The main story will be the tranquil weather pattern into the
weekend. Although milder daytime temperatures will result in
snowmelt each day, nighttime lows are expected to remain below
freezing through Saturday, resulting in more of a gradual melt.
This, combined with a lack of additional rainfall should mitigate
the threat of significant flooding. Rivers across east-central
Wisconsin will remain high through the week. River levels north
and west of the Fox Valley are expected to be on the rise later
this week into the weekend due to the expected snow melt across
the north.

There is a slight chance of rain/snow showers across the far
north Wednesday evening, otherwise dry conditions are expected
into the weekend. The only exception may be Thursday afternoon
across far northeast Wisconsin where there could be a few isolated
rain showers during the afternoon. Did not add a chance of rain
for this period at this time due to the low confidence rain would
occur. There is a great deal of uncertainty in the precipitation
chances Sunday into Monday across the region due to the large
spread in the model guidance. Precipitation should be rain during
the day and a rain/snow mix at night if precipitation occurs.
Only made minor changes to max/min temperatures based on our
typical warm/cold spot locations. Temperatures should be at
or slightly above normal into the weekend.
&&

.AVIATION...for 06Z TAF Issuance
Issued at 1051 PM CDT Mon Mar 18 2019

VFR conditions will be in place through much of this forecast
period. The exception may be some MVFR conditions later tonight as
an upper-level system passes to the northeast and to the
southwest of the area. Not overly confident in the lower cloud
cover as upstream observations are only supporting higher end MVFR
conditions around 3000ft - 4200ft. These may actually just miss
the TAF sites. Otherwise, higher clouds are expected to stream
across the area through much of this time period as shown on
visible and IR satellite imagery.
&&

.HYDROLOGY...
Issued at 319 AM CDT Tue Mar 19 2019

Flood warnings are in effect for a few rivers in east central
Wisconsin. Rain amounts in the coming days are expected to be
fairly light, with overnight lows being cold enough to stop
melting during the overnight hours. Therefore the flooding is
not expected to be exacerbated by any of the light precipitation
expected at times during the upcoming week.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM.....Kurimski
LONG TERM......Eckberg
AVIATION.......Cooley
HYDROLOGY......Kurimski