Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
FXUS63 KMKX 300800
Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
300 AM CDT SAT JUL 30 2016
.TODAY AND TONIGHT...Forecast confidence is medium.
A deep moist axis continues to lay across southern Wisconsin. We
remain under a very weak flow environment within a deep, weak
trofing pattern. This pattern continues to shift very slowly to the
south and east with time, but we remain under a chance of more
random showers and thunderstorms over areas mainly south of
Milwaukee and Madison. We should get into some lower dewpoints
today, especially over the northern half of the forecast area.
Things look to shift far enough east by tonight, that we`ll keep the
dry forecast going.
.SUNDAY AND MONDAY - Confidence...Medium
Surface high pressure will dominate. There is a lingering vort axis
that slides through on Sunday. However the primary mid level trough
will have shifted off to the east. 925 temps will continue to be
around 20c on Sunday with just a subtle uptick on Monday.
.MONDAY NIGHT AND TUESDAY - Confidence...Medium
Building hot dome to our west will result in mcs development within
the waa zone on the eastern periphery of this building ridge. The
500 millibar progs do show shortwave energy riding southeast through
the Upper Midwest with hint of a southwest 850 jet max coming into
play though doesn`t look overly strong. The influence of upper jet
is proggd to be well north of WI. The chancy Superblend pops look
ok for now but as we draw closer and zero in on the mcs track the
pops could go higher especially in the southern and western
portion of the cwa. The time frame for a potential MCS will be
from later Monday night into Tuesday evening. Temps will be rising
as the sfc/925 warm front lifts northeast into srn WI. However
convection trends will dictate highs so confidence not high enough
to boost over the Superblend numbers.
.WEDNESDAY AND WEDNESDAY NIGHT - Confidence...Medium
The ECMWF and GFS linger some waa and show some signals for precip
development, and also agree that the main event will be the earlier
discussed mcs. So, will leave the small Superblend pops in place for
now on Wednesday, but this looks to be a very warm and humid period
as heights continue to build and 925 temps reach the mid 20s
celsius. So a considerable boost through the 80s expected. At this
time it looks like Wednesday night will be a warm one as well with
the focus proggd to be to our north with a very warm/humid airmass
.THURSDAY AND FRIDAY - Confidence...Medium
Mid level flow is proggd to flatten and bring a frontal boundary
through the area. At this time it looks like the main frontal precip
would arrive Thursday night. The GFS shows a continuation of the
very warm/humid conditions Thursday while the ECMWF develops more
prefrontal activity during the day. Typically in these situations
we are capped off until the front arrives. So if the GFS 925 temps
were to verify the 28-31c 925 temps that are projected our current
highs would need a good boost. Low level flow shifts nw on Friday
with some decrease in temps/dew points expected with frontal
boundary shifting to our south.
.AVIATION/12Z TAFS/...Expecting VFR CIGS and VSBYS during the period.
However, CIGS will be flirting close to the MVFR threshold, especially
across the southeast where we have some better moisture advecting
in from the east. Additionally, there is a small chance of showers
or an isolated thunderstorm today, mainly south of Milwaukee and
Madison. Winds will remain northeast at 10 knots or less.
.MARINE...Northeast winds of 10 to 15 knots will persist through
the morning, then gradually relax this afternoon. Look for waves
of 2 to 3 feet gradually diminishing through the day. Winds and
waves are expected to remain below small craft advisory levels
through much of next week.
TODAY/TONIGHT AND AVIATION/MARINE...Davis
Sunday THROUGH Friday...Collar