Area forecast discussion
National Weather Service Milwaukee/Sullivan WI
321 PM CDT Wednesday Jun 19 2013
Tonight...forecast confidence...high
Lingering influence of retreating high pressure will dominate.
One last night of a cool dry airmass. 925 temperatures of 16-18c combined
with at least a moderate inversion setting up suggests lows in the
dropping at least to the l/m50s.
Thursday...forecast confidence...medium
850 millibar moisture transport increases. Axis of low level jet
remains well west of our area but 850 dew points do increase with
time. Shortwave traverses the area. A blend of 12z NAM and 00z European model (ecmwf)
yields some probability of precipitation in portions of SC WI. However 12z European model (ecmwf) has pulled
back even further on quantitative precipitation forecast keeping all of County Warning Area dry. Will have some
small probability of precipitation in the south central to blend with the western
offices...but conceivably the precipitation could hold off to our west if
the new European model (ecmwf) is right. 925 temperatures of 20-22c gives inland highs of 80
to 85.
Thursday night through Saturday...forecast confidence...medium
Will see a chance for showers and storms mainly northwest half of
the forecast area Thursday night as a shortwave approaches...with
best moisture and lift from warm advection across this area of
higher probability of precipitation. The shortwave will then move through on Friday...with a
chance for showers/storms across the forecast area.
Yet another shortwave will bring more storm chances Friday night
into Saturday. Will see increasing cape values into the weekend as
a warmer and more humid airmass arrives. Also...GFS and NAM
precipitable water values are predicted to be about 125 to 150
percent of normal. Think the instability and precipitable water values are a bit
overdone given the likely too high NAM/GFS low level moisture.
Even so...looks like a decent environment for storms given a
sufficient trigger. Could see a few strong to severe storms by
Friday or Saturday...though low level flow and bulk shear are not
too impressive either day.
Should see above normal temperatures Friday and Saturday. Exact highs kind
of tricky though...with model 925 mb temperatures differing by a couple
degrees and uncertainty with coverage of clouds and precipitation.
Sunday through Wednesday...forecast confidence...medium
Looks like continued warm and humid weather into the middle of next
week. A chance for storms will continue...with models depicting a
couple more shortwaves to move through the area. Above normal temperatures
will continue through this period...possibly getting a bit toasty
and cracking 90 a couple days.
&&
Aviation/00z tafs/...high pressure in the eastern Great Lakes will
continue to have a hold on southern WI weather for much of this period. VFR
sky clear through tonight. Models bringing precipitation into portions of SC WI
Thursday due to 850 millibar moisture advection and a 500 millibar
shortwave. Will keep msn taf dry through at least 18z Thursday. Best
chance will be west and north of kmsn after 18z. Eastern taf sites
remain dry though 00z.
&&
Mkx watches/warnings/advisories...
WI...none.
Lm...none.
&&
$$
Tonight/Thursday and aviation...collar
Thursday night through Wednesday...ddv
