Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KMKX 130338
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
938 PM CST Mon Feb 12 2018

.UPDATE...

Temperatures are tumbling this evening given deep snow cover and
light to calm winds. The thin cirrus blanket has, so far, been
unable to slow the drop much, so lowered minimum temperatures
across the board. Also made some local tweaks accounting for
valley locations which will easily have time to drop below zero
before the cloud cover thickens up later this evening. Otherwise,
the forecast is in good shape.

&&

.MARINE...

Look for relatively quiet conditions for tonight. Southerly winds
will increase for Tuesday into Wednesday, potentially reaching
Small Craft levels on Wednesday into Wednesday night

&&

.PREV DISCUSSION... (Issued 531 PM CST Mon Feb 12 2018)

UPDATE...

Increased near-term cloud cover due to high level moisture
streaming into the area this evening. Otherwise, no changes to the
ongoing forecast.

AVIATION(00Z TAFS)...

VFR through the period. Look for high level clouds this evening
with some mid level clouds by Tuesday morning.

PREV DISCUSSION... (Issued 232 PM CST Mon Feb 12 2018)

SHORT TERM...

Tonight and Tuesday...Forecast Confidence...High

Zonal upper flow with the entrance region of the jet max moving
off this evening, as a second jet forms over northern Illinois.
Weak upper level divergence and 700 mb upward motion. 700 mb RH
increases, and saturates on Tuesday. Low levels are rather dry.
Temperatures should drop rather quickly tonight due to the snow
cover and light winds with the surface high. A weak southwest
flow begins Tuesday, with a moderation in temperatures.

Tuesday night and Wednesday...Forecast Confidence...Medium

The upper flow remains rather zonal. The southwest surface flow
increases, along with low level moisture. As a result stratus may
form, especially Wednesday.

LONG TERM...

Wednesday night through Thursday night...Forecast Confidence...Medium

A broad mid/upper trough approaches.

Biggest problem initially is fog potential. SREF has a rather
high signal with low visibilities developing Wednesday night into
Thursday morning.

The ECMWF has trended toward the drier GFS during this period,
with precipitation reaching southern Wisconsin Thursday night with
the upper trough, while the bulk of the precipitation is along the
frontal boundary well south.

Friday through Sunday...Forecast Confidence...Medium

A more west/northwest upper flow is in place, before it becomes
more zonal Saturday night. The upper flow becomes southwest ahead of
a strong shortwave over the northwest U.S.

Looks like quiet weather with high pressure Friday, then a
renewed warm air advection pattern setting up Saturday and Sunday.

Low levels become more moist Sunday night, with the GFS bringing a
trough and cold front in late Sunday, but the slower ECMWF keeps
the front near, or just northwest of southern Wisconsin Monday.

AVIATION(21Z TAFS)...

VFR conditions. Cirrus increasing then mid level clouds spread in
Tuesday morning. Light wind regime today into tonight with
surface high centered over the Great lakes. Winds will become
more southerly on Tuesday with the high to our east.

MARINE...

GOES 16 visible suggests some thin slushy ice, with a larger
patch toward open waters east of Wind Point. High pressure
dominates tonight. Winds may approach small craft levels by
Wednesday as south winds strengthen.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...None.
&&

$$

Update...SPM
Tonight/Tuesday and Aviation/Marine...Hentz
Tuesday Night through Monday...Hentz



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.