Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 222032

Area Forecast Discussion
National Weather Service Duluth MN
332 PM CDT Tue May 22 2018

.SHORT TERM...(This evening through Wednesday)
Issued at 254 PM CDT Tue May 22 2018

A field of cumulus is suppressing high temperatures across much
of the Northland except along the Canadian border. Winds are also
quite light being under a broad pressure gradient. Because of the
clouds, RH`s are generally in decent shape in the mid 50s, so fire
weather not much of a concern except right along the Canadian
border. Even then, winds are light.

Light winds and radiational cooling may lead to some patchy fog
especially across Wisconsin overnight.

Wednesday will be similar to today except less clouds as an upper
level ridge moves squarely overhead.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 254 PM CDT Tue May 22 2018

The main focus for the extended periods continues to be on the
slow moving series of disturbances that will affect most of the
Northland during the Wednesday night though Sunday time period.

A strong surge of low level warm/moist advection will move into the
Upper Midwest Wednesday night as a 30-35 knot low level jet develops
in the 925-850 mb layer in advance of the lead short wave trof
moving into the Dakotas. Deep layer shear is expected to be fairly
weak within the strengthening warm frontal zone across northern
Minnesota during this time, but the rapid influx of higher quality
moisture should be sufficient for the development of elevated
showers and thunderstorms across much of the Duluth CWA Wednesday
night into Thursday morning until the low level jet goes into its
diurnal weakening phase during the day Thursday.

Chances for deep convection should then reorganize Thursday
afternoon with daytime destabilization.  However, the initial
redevelopment given available model guidance at this time appears as
though it will be north and west of the Duluth CWA - across Ontario
along the main warm frontal zone/CAPE gradient, and in the vicinity
of a surface trof/confluence axis that is forecast to set up over
the eastern Dakotas.  Thus, the best chances for thunderstorms
across the Duluth CWA will likely be Friday night into Saturday
morning as a complex of showers/thunderstorms moves eastward from
the initiating area in the eastern Dakotas.  While weak deep layer
wind shear will likely be a limiting factor in the chances for
storms becoming highly organized or severe, there is at least some
chance of a few strong storms given the degree of instability that
is expected to be in place.

The primary upper level trof axis is expected to only slowly move
eastward Saturday and Sunday, with at least some risk of showers and
thunderstorms continuing.  This is a change from yesterday when it
appeared as though precip chances would end late Saturday.  Now, it
appears as though there could be a fair amount of showers and storms
around on Sunday as a lobe of colder temps aloft brushes across the
northeast half of the CWA near max heating time.


.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1231 PM CDT Tue May 22 2018

VFR conditions are expected to prevail for all TAF sites through
most of the period with light and variable winds. MVFR conditions
or lower are possible at HYR tomorrow morning, but went with MVFR
for now due to low confidence.


DLH  53  80  54  80 /   0  10  50  40
INL  48  84  57  84 /   0   0  30  30
BRD  53  81  59  86 /   0  20  60  40
HYR  51  82  60  84 /   0  10  50  40
ASX  49  80  51  81 /   0   0  30  40




LONG TERM...Miller
AVIATION...Wolfe/KC is the U.S. government's official web portal to all federal, state and local government web resources and services.