Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Duluth Minnesota
328 am CDT Sat Aug 30 2014

Short term...(today and tonight)
issued at 320 am CDT Sat Aug 30 2014

An elongated area of low pressure currently positioned over Lake
Superior/Wisconsin...will gradually slide east through the day.
Rain will persist over the northern Wisconsin zones early this
morning...then gradually diminishing. Canadian high pressure
anchored over Ontario will allow for drier air to sink into the
northern zones/Borderland today. However...elsewhere sufficient low
level moisture will produce patchy drizzle this morning...with
lingering clouds through the day. There is a small chance for an
isolated thunderstorm this afternoon in the Brainerd lakes region...where
latest high resolution models are showing a short wave tracks
across cen Minnesota with sufficient moisture and cape to support
convection. High temperatures today will top out in the 60s to
lower 70s.

Long term...(sunday through friday)
issued at 320 am CDT Sat Aug 30 2014

Strong warm air advection and increasing moisture will be seen ahead of low
pressure/cold front and upper trough advancing from the plains. 800 mb
temperatures forecast to warm at least 8 degrees from this morning until
Sunday morning. Major moisture transport on strong 800 mb jet of 40 kts
will aid in some high rainfall rates with precipitable waters exceeding 1.5
inches. With strong shear and very unstable atmosphere ahead of the
front...expect a round of severe thunderstorms as described by Storm Prediction Center swody2. By
Sunday afternoon MUCAPES will range from 2500 to over 3000
j/kg...lifted indice's will be well below zero...tt's over 50. All the
parameters will be in place...and added lift provided by
front...upper vorticity...and upper divergence from jetlet rounding the
upper trough Sunday night and Monday. At this point the models are in
fairly agreement with the timing and strength of this system. While
the bulk of the storms will be Sunday evening...a first round could
be as early as Sunday morning when an initial wave helps storms
erupt in western Minnesota and some of these could reach into the western
forecast area then continue east through the day. The storms will
continue Sunday night ahead of the front. By Monday morning the
front should be into northwestern WI...and exit by Monday afternoon.

The rest of the extended period will feature a progressive westerly
flow. This means a series of S/waves embedded in the upper flow will
bring series of upper troughs across the upper Midwest and chances of
showers and thunderstorms through much of the week.

&&

Aviation...(for the 06z tafs through 06z Saturday night)
issued at 1230 am CDT Sat Aug 30 2014

A slow moving low pressure system will continue to impact the
Northland through the night and even into Saturday. The low will
gradually move off and the effects will lessen on Saturday. Rain will
continue across northern Wisconsin along with a few thunderstorms.
IFR/LIFR and MVFR will give way to VFR on Saturday. Fog will
continue to develop overnight but will gradually lift Saturday
morning.

&&

Preliminary point temps/pops...
dlh 67 54 70 61 / 10 10 40 80
inl 73 52 73 57 / 10 10 70 70
brd 72 59 78 60 / 20 10 70 80
hyr 71 53 79 64 / 70 10 20 80
asx 65 52 78 63 / 40 10 20 80

&&

Dlh watches/warnings/advisories...
Minnesota...none.
WI...none.
Ls...none.
&&

$$

Short term...graning
long term...clc
aviation...clc

National Weather Service Glossary of Abbreviations