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FXUS63 KDLH 261756 AAB

Area Forecast Discussion...UPDATED
National Weather Service Duluth MN
1256 PM CDT Sun Mar 26 2017

Issued at 1256 PM CDT Sun Mar 26 2017

An updated aviation discussion for the 18z TAF issuance is below.


.SHORT TERM...(Today through Monday)
Issued at 447 AM CDT Sun Mar 26 2017

A cutoff low was centered over western Illinois early this 
morning with an arc of cyclonic vorticity advection over southern 
Minnesota through northern Wisconsin. Drizzle and freezing drizzle
continued over portions of east-central and northeast Minnesota, 
including the Twin Ports and along the North Shore. A more intense
area of precipitation was over northern Wisconsin. Numerous 
"Unknown Precipitation" reports have been received as the band 
lifted northwest across central Wisconsin. Surface air 
temperatures remain a few degrees either side of freezing, but 
MNDoT RWIS pavement temperatures are above freezing. Checked with 
local law enforcement agencies and no reports of slippery roads 
had been received through 3 AM. No changes to the Winter Weather 
Advisory for Iron County, but will make more phone calls in the 
next few hours. May need to extend the headlines farther west 
should ground truth support more freezing rain than presently 
expected. Regional radar mosaic indicates a broad area of showers 
behind the initial precipitation band. Think the showers will lift
into the Northland later this morning and linger into tonight. 
Temperatures will gradually warm today with precipitation changing
back to all rain by mid to late morning. Nudged high temperatures
a bit cooler for this afternoon due to continued cloud cover and 
limited heating.

Another shortwave trough over the Rockies this morning will kick 
the cutoff low eastward tonight. Look for the showers to decrease 
in coverage and slide eastward overnight. Temperatures should cool
into the middle 20s to low 30s. Precipitation may change back to 
a wintry mix overnight. Another ribbon of cyclonic vorticity will 
stretch northward from the second shortwave over the Central 
Plains tonight and Monday, while a northern stream trough pushes 
across the Canadian Prairies and into the Upper Midwest. The 
coverage and intensity of precipitation may increase during the 
day Monday as these features move through the area. Held onto POPs
over northwest Wisconsin where additional precipitation is most 

.LONG TERM...(Monday night through Saturday)
Issued at 447 AM CDT Sun Mar 26 2017

An upper level short wave trough will clip the Arrowhead and 
northwest Wisconsin Monday night. This will generate the last of a
few showers over Price County, where the best moisture is 
available, early in the evening before ending. High pressure will 
be covering the rest of the forecast area. Surface and upper level
ridging will cover the region Tuesday through Wednesday. 
Wednesday night through Friday finds a series of upper shortwaves 
traveling across the area. Meanwhile, a vertically stacked system 
will be moving through the central Plains. Also, surface high 
pressure will be nearby. Long range models begin to diverge on the
handling of these features. The ECMWF/GEM are the wettest with 
precipitation chances along the southern half of the forecast area
through Thursday night. The GFS keeps the region dry with ridging
affecting the area. Used a blend to account for these issues. 
This also affects the P-types. will keep it simple for now with 
rain during the day, rain/snow mixed in the evening and snow 
overnight. Friday and Friday night finds the GFS and ECMWF with 
ridging over the region, the GEM has that previously mentioned 
stacked system drifting through Wisconsin. Maintained the blended 
approach here as well. On Saturday, the GEM/ECMWF have ridging 
nearby, while the GFS brings a shortwave through the area with a 
cold front. More blending was conducted on Saturday. Temps will be
running near to slightly above normal.


.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1256 PM CDT Sun Mar 26 2017

MVFR to IFR conditions are expected to persist for most of the
next 24 hours. Temps have risen above freezing, so any additional
precip this afternoon will be in the form of light rain. Rain 
should taper off this afternoon, with perhaps a few lingering 
showers or periods of drizzle into this evening. With light winds 
and a nearly saturated boundary layer, low clouds are expected to 
persist, with fog reforming overnight and Monday morning.


DLH  37  30  42  28 /  90  20  10   0 
INL  46  29  45  26 /   0   0   0   0 
BRD  43  33  52  31 /  30  10  10   0 
HYR  42  31  44  27 /  80  40  20  10 
ASX  38  31  41  27 /  80  30  20  10 



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