Area forecast discussion
National Weather Service Milwaukee/Sullivan WI
320 am CDT Wednesday Jun 19 2013
Today and tonight...forecast confidence is high.
High pressure stretches across the entire Great Lakes region with
sounder precipitable water imagery showing a very dry airmass in
place across the forecast area. Few if any clouds today with
temperatures expected to run about 4 to 6 degrees warmer than
yesterday. Nearly perfect by most measures.
The high begins to slip off to the east southeast tonight...but
keeps things mostly clear and cool for another night. The return
flow with warm and more moist air begins to take shape for the
remainder of the week.
Thursday through Friday night...forecast confidence is medium.
Short term models continue to show gradual 850mb warm air
advection and low level moisture advection occurring across the
area during this period. 850mb low level jet nose focuses
northwest of the area Thursday...then to the north Thursday night.
This keeps most of the quantitative precipitation forecast associated with any convection and
possible mesoscale convective system to the northwest and north of
the area.
Still have the surface warm front moving north through the area
during this time...as well as a modest 500mb vorticity maximum
passing east through the area. Area forecast soundings from NAM
fairly moist in middle levels Thursday night with weak elevated cape.
GFS is quite dry during this time. For now...left lower end probability of precipitation
going for this period. Temperatures will slowly warm during this
time...though will be cooler near Lake Michigan Thursday with
onshore winds.
Short term models keep the surface warm front north of the area
Friday and Friday night...with the warm sector airmass over the
forecast area. 850mb low level jet nose gradually focuses more over
southwest and south central Wisconsin Friday into Friday night.
Various 500mb vorticity maxima push through the region as well.
Area forecast soundings from NAM are more moist during this
time...and show decent elevated cape and little to no cap. In
contrast...the GFS is drier and capped to surface and some elevated
air parcels. NAM tries to bring quantitative precipitation forecast into the area at times during
this period...with the GFS keeping most just to the north.
For now...will continue to bring medium range probability of precipitation for this period.
Warmer and more humid air should work into the area during this time.
Saturday through Tuesday...forecast confidence is medium.
Still a fair amount of disagreement between the GFS and European model (ecmwf) during
this period. The GFS continues to keep the warm front north of the
area Saturday...then pushes it northward Saturday night and Sunday.
Southwest flow at 500mb also lingers Saturday into Sunday. Most of
the quantitative precipitation forecast associated with the front thus stays north of the area...and
keeps the warm and humid conditions across the area.
The European model (ecmwf) continues to keep the warm front and associated quantitative precipitation forecast across
the area during this time. For now...will continue to use consensus
probability of precipitation and temperatures for Saturday through Sunday.
Southwest flow at 500mb becomes more zonal Monday into Tuesday
across the region. GFS more aggressive than European model (ecmwf) with secondary
push of warm air advection and associated quantitative precipitation forecast later Monday into
Monday night. Southwest winds near the surface continue to bring
warm and humid conditions into the region. Used consensus probability of precipitation and
temperatures for this period as well.
&&
Aviation/12z tafs/...
VFR conditions through the period. Winds less than 10 knots.
&&
Mkx watches/warnings/advisories...
WI...none.
Lm...none.
&&
$$
Today/tonight and aviation/marine...Davis
Thursday through Tuesday...wood
