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Area forecast discussion 
National Weather Service Green Bay WI
354 am CST Sat Nov 22 2014

Forecast discussion for routine morning forecast issuance

Short Sunday
issued at 352 am CST Sat Nov 22 2014

Strong low level jet is helping to produce drizzle and freezing
drizzle across southeast Wisconsin at 09z. It was having a hard
time getting as far north as Highway 151 so we decided to drop the
Freezing Rain Advisory. There may still be some patchy drizzle or
freezing drizzle this morning but do not expect a big event.
Strong warm advection will produce temperatures close to normal

Low clouds...drizzle and fog expected tonight as dew points in the
30s and 40s over the Missouri River valley move northeast into
Wisconsin. Dense fog possible where there is deep snow cover. Lows
tonight will likely occur in the early evening with rising
temperatures overnight.

Sunday should be cloudy and mild with increasing chances of rain
as the day GOES on. Highs in the 40s are likely in most places
with a few 50 degree readings possible.

Long term...Sunday night through Friday
issued at 352 am CST Sat Nov 22 2014

There is no shortage of potential pitfalls in this portion of the
forecast making forecaster confidence rather low. Confidence falls
rather quickly Sunday night when a deep cyclone moves north over the
central Great Lakes. The GFS/Gem have trended significantly
stronger with their 00z runs...while the NAM/European model (ecmwf) are weaker
compared to the ensemble guidance. A stronger solution is
possible...but not to the extent of the GFS. So will go with a GFS
ensemble mean/Gem blend. Thereafter...the European model (ecmwf) is more in sync
with the GFS ensemble mean but there is quite a difference between
the European model (ecmwf) and GFS by 00z Friday. Will side with the European model (ecmwf) for
later periods.

Sunday night through Monday night...low pressure will deepen rapidly
as it lifts northward Sunday night from the central Mississippi
Valley to northwest lower Michigan. Ahead of the low...increasing
upper divergence and qg forcing supports a large area of
precipitation spreading across the region during the evening.
Plenty of warm air ahead of the ptype should be rain for
much of the night until late when colder air moves into central and
north-central Wisconsin...and could change precipitation to a mix or all
snow. Colder air will continue to wrap behind the system and spread
across the area during the day on Monday as the low lifts into
Ontario. Potential is improving for accumulating snow everywhere on
Monday...though its still rather difficult to get a handle on
possible accums since the details remain elusive. But if trends
continue to support a stronger solution...a 1-3 or 2-4 inch event is
possible. Blowing and drifting will also become an issue with any
snowfall since gusts 30 to 35 miles per hour will be a distinct possibility.
The snow will gradually taper off Monday night except within the
snow belt where wind trajectories will be favorable for good
accumulations. Will show the highest snow amounts there which could
surpass warning criteria since favorable wind trajectories could
occur for 12-18 hours.

Rest of the forecast...any lingering snow within the snow belt or
northeast Wisconsin will exit Tuesday morning as the large cyclone
continues to move away from the region and surface ridge axis builds
in. The next chance of snow will occur Wednesday into Wednesday
night when the next clipper drops into the region. Behind the
clipper a 1035-1040mb Arctic high will move into the region...which will
bring another round of very cold temperatures and lake effect to the snow
belts through Thursday. The cold blast could be short-lived as
return flow ramps up Friday into early next weekend.

Aviation...for 06z taf issuance
issued at 1024 PM CST Friday Nov 21 2014

A south to southwest low-level jet to 50 kts will transport a
warmer/more moist air into the area overnight. As a result low level wind shear
conditions will continue overnight. Look for MVFR ceilings to become
widespread...with patchy LIFR/IFR ceilings later tonight into
Saturday. Light freezing rain/drizzle will developing
overnight...and linger into Saturday morning. As warmer
temperatures arrive by middle day Saturday...the freezing precipitation should
turn to mainly patchy drizzle for the rest of the day. &&

Grb watches/warnings/advisories...


Short term.....Rdm
long term......mpc

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