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Area forecast discussion 
National Weather Service Green Bay WI
606 am CDT Wednesday Jul 29 2015

Updated aviation portion for 12z taf issuance

Short Thursday
issued at 312 am CDT Wednesday Jul 29 2015

An unusually strong low pressure system is currently tracking
through southern Canada. The cold front associated with this
system is currently making its way through northeast Wisconsin
early this morning. However despite MUCAPES of a few hundred j/kg
the best this front can muster is a few stray showers as it passes
through our area. This is likely due to the amount of dry air in
place across the evidenced by the 00z kgrb radiosonde observation
sounding. Given the lack of convective activity associated with
the front will remove thunder from the forecast and just go with a
chance for showers as the front passes through this morning.

Behind the cold front...a tight pressure gradient with the wrapped
up low will bring gusty winds to the area today. Mixing heights up
to around 5k feet will bring down gusty winds to the surface...with
gusts of 30 to 35 miles per hour possible at times this afternoon. Continued
the trend of cooler than MOS temperatures today given the upstream
observed high temperatures upstream behind the cold front

The region dries out tonight and Thursday as high pressure builds
to the south with the aforementioned low situated across Hudson
Bay. This will keep the region between these two system...with
continued breezy conditions expected on Thursday. Northwest flow
will continue to keep high temperatures below MOS guidance on
Thursday as 850 mb temperatures hover in the middle teens.

Long term...Thursday night through Tuesday
issued at 312 am CDT Wednesday Jul 29 2015

The latest ensemble means show west-northwest to northwest upper
flow for much of the period with an occasional northern stream cold
front dropping south through the region. For much of the time...the
tropical heat and humidity will be suppressed to the south...while
temperatures will be close to normal across the state. Looking at
the medium range models tonight...the European model (ecmwf) appears to have better
alignment with the ensemble prefer its solution.

Thursday night through Friday night...quiet and breezy for Thursday
evening...but will see middle-clouds increase after midnight ahead of a
cold front dropping in from the north. This front will pass across
the region late in the night and Friday morning without much
fanfare. Both the European model (ecmwf) and GFS produce light showers with the
frontal passage. But looking at prognosticated soundings...moisture is
located within a narrow range above 10 kft. Awfully tempting to go
dry as a result...but will leave a chance of sprinkles in the
forecast. Following the front...should see plenty of sun with highs
in the upper 70s to middle 80s. Continued quiet on Friday night under
mostly clear skies. Little change to temperatures over the period.

Rest of the forecast...weak high pressure will hang around on
Saturday which looks sunny and seasonable. Uncertainty increases
Sunday into Monday as guidance indicates a weak trough moving
through on Sunday as a weak shortwave passes by to the south. This
will be followed by another Canadian front Sunday night into Monday.
The best chance of rain looks to be with the Canadian front though.
Turning cooler and less humid Tuesday and Wednesday.

Aviation...for 12z taf issuance
issued at 606 am CDT Wednesday Jul 29 2015

The cold front has pushed through relatively dry. Skies will clear
out and winds will increase in the wake of the front this morning.
Much higher winds are expected later today once mixing begins with
sustained winds around 20 knots and gusts to around 30 knots.
Winds should subside tonight to around 10 knots or so with
continued clear skies.

Grb watches/warnings/advisories...


Short term.....Kurimski
long term......mpc

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