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fxus63 kdlh 290539 

Area forecast discussion
National Weather Service Duluth Minnesota
1239 am CDT Mon may 29 2017

issued at 645 PM CDT sun may 28 2017

Am in the process of doing some updates to the forecast for the
latest radar trends, that should be out shortly. Below is an
aviation update.


Short term...(this evening through monday)
issued at 256 PM CDT sun may 28 2017

There were numerous showers and storms across the Northland this
afternoon and these will continue for most of the night and
Monday. But, I think we should see some decrease in coverage as
solar support is lost. The culprit is a deep low pressure area
over southern Manitoba and northwestern Quebec. Vort maxima will
be rotating around the low and over the Northland. One went
through this morning and early afternoon and another is coming
through Minnesota and a few more are still upstream, taking aim on the
Northland. With a low freezing level, these storms have been very
low-topped and especially productive small hail producers. Had a
pilot report of thunderstorm top over Duluth of only 20,000k feet.
Expect about the same type of weather Monday, but maybe not quite
so rambunctious as the temperature lapse rate won't be quite as
strong with warmer 500 mb and little instability.

Long term...(monday night through sunday)
issued at 256 PM CDT sun may 28 2017

The closed upper low meanders around northwest Ontario Monday night
through Tuesday night. Several pieces of energy, along with a pair
of tight short wave trofs, will rotate through the forecast area
during this time. Periods of showers are expected, but will be
difficult to time. This leads to the chance pops that will be
carried in the forecast through Tuesday night. Much cooler temps are
forecast as 850mb temps drop to near zero celsius through this
period. The rain will end from west to east Tuesday night as high
pressure builds into the region. After a dry Wednesday morning,
model differences begin in the afternoon. The NAM/Gem are dry, the
European model (ecmwf)/GFS pop some showers over northern Minnesota. This continues
Wednesday night. Used a blend which led to small pops over The
Arrowhead early, then dry overnight into Thursday morning. Thursday
afternoon finds only the Gem dry, the GFS/European model (ecmwf) have some showers.
Have pops over the eastern third of the region to account for a
short wave trof dropping south from Canada. The last piece of energy
moves over northwest Wisconsin Thursday evening and have some small
pops in place. Dry elsewhere as high pressure arrives. Ridging
covers the area on Friday. Friday night through Saturday shows a
large model spread. The Gem has ridging, the European model (ecmwf) develops a
surface low over southern Minnesota and has a large swath of qpf,
the GFS is between. Used a blend which results in low pops Friday
night and Saturday.


Aviation...(for the 06z tafs through 06z Monday night)
issued at 1239 am CDT Mon may 29 2017

Cyclonic flow both at the surface and aloft in combination with
diurnal heating and some weak impulses aloft will keep showers in
the terminal forecasts through much of the taf period. A surge of
colder air moving into the area from the northwest will sweep some
IFR ceilings into the terminals beginning shortly after issuance
time and continuing through at least 15z, slowly improving to MVFR
afterwards. Ceilings are likely to deteriorate again after 02z, but
this is most likely farther north and have limited this only to kinl
for now. Where clouds clear for a short while for the next several
hours fog may form, but have left out for now and will have to
monitor for later fog development.


Preliminary point temps/pops...
dlh 46 56 43 54 / 40 70 20 30
inl 47 54 43 54 / 70 70 30 40
brd 49 57 45 57 / 30 40 20 20
hyr 47 57 44 56 / 30 70 30 40
asx 48 59 45 56 / 50 70 40 30


Dlh watches/warnings/advisories...


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