AFOS product AFDFGF
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Displaying AFOS PIL: AFDFGF
Product Timestamp: 2020-01-29 12:38 UTC

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FXUS63 KFGF 291238
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
638 AM CST Wed Jan 29 2020

.UPDATE...
Issued at 635 AM CST Wed Jan 29 2020

Light snow continues to spread into northeast North Dakota with
snow being reported as far northwest as Brandon, MB. Latest RAP
soundings showing ice in the cloud through late morning, when it
begins to dry out while lower levels saturate. Adjusting hourly wx
grids for all snow through 10 AM, transitioning back to freezing
drizzle and/or snow by noontime. Fog has improved somewhat but
HRRR vsbys had lower vsbys advecting in from west aft 12Z, so will
keep headlines in tact.

&&

.SHORT TERM...(Today through Thursday)
Issued at 304 AM CST Wed Jan 29 2020

Key forecast challenges this short term period will be dense fog
west of the valley this morning and freezing drizzle potential
across the north today. Travel-related impacts associated with
dense fog can be expected west of the valley through noon, with
the primary impact being visibilities less than one-quarter mile.
A dense fog advisory has been issued for this impact.

Today...Dense fog will gradually spread along and west of a
Langdon to Havana line...with visibilities falling below one-
quarter mile.  Conditions will improve by late morning.

Across the north (mainly north of Highway 2), an area of light
snow or freezing drizzle will slowly move across northeastern
North Dakota and northwest Minnesota, weakening and moving out of
the are around 9 PM tonight. Soundings show significant dry air
aloft, supporting light freezing drizzle, unless lift is enough to
saturate the column into the dendritic zone. The first few
observations reporting precipitation this morning have been light
snow at Walhalla and Cavalier, so will continue to monitor for 
signs of freezing drizzle. There could be some slick areas across 
the northern valley and northwest Minnesota by late afternoon. Not
confident either way (freezing drizzle vs. snow) so will continue
the wintry mix messaging.

Tonight...area of snow/freezing drizzle will weaken as upper wave
translates east of the area by late evening, with mainly flurries
or dry after midnight. Some patchy fog may develop east of the
valley, but so far models not bringing fog back to the west
Thursday morning. However, given the southerly flow and recent
trends, not confident that fog will not present itself again
late tonight into tomorrow morning.

Thursday...Return flow strengthens and will mark the beginning of
the advertised warming trend that will continue through the
weekend. Daytime highs should reach the upper 20s for most of the
area.

.LONG TERM...(Thursday night through Tuesday)
Issued at 304 AM CST Wed Jan 29 2020

Thursday night: We may have one more shot of light or non 
measurable precipitation Thursday night as a mid/upper trough passes 
over our region with closed center migrating over our CWA. Moisture 
advection is weak and while synoptic forcing will be present 
organized forcing seems to split around our CWA. Ensembles still 
hint at possible spotty/weak precip, however NBM has trended lower 
on measurable chances. Still, considering profiles either flurries 
or even a few pockets of freezing drizzle can't be ruled out. Not a 
lot of confidence considering trends, but we'll want to monitor in 
the event of light icing and potential travel impacts if/where 
precip sets up. 

Friday-Sunday: Ridging amplifies from the Pacific Northwest and 
Northern Rockies before sliding east and eventually transitioning to 
strong upper level westerly flow by Saturday night-Sunday. This 
pattern is much less favorable for any precip and current 
NBM/ensembles support dry conditions. This pattern does support both 
strong WAA aloft and anomalously warm temps in the 925-850 MB layer. 
GEFS mean continues to be warmer with its clustering, though it's 
mean is in line with ECMWF ensemble mean in general. It's going to 
be warmer and it appears likely we'll see most locations reach or 
exceeded freezing Saturday and Sunday, and it is certainly possible 
we may see locations reach 40. There is strong clustering in GEFS 
plumes towards widespread 40-42 for highs by Sunday, but these 
values will likely be conditional on sky cover, timing of an 
approaching arctic front, and may struggle in parts valley as we 
often see during winter time periods (terrain effects and snow 
cover). 

Monday-Wednesday: Arctic cold front passage is still expected to 
bring seasonal cold back into our region for early next week. The 
parent trough and cold front show good consensus between models on 
general pattern, however precipitation is still uncertain Mon-Mon 
night and NBM just barely introduces slight chance PoPs. Outliers 
still show potential for banded accumulating snow, but this is not 
in line with means and confidence is low that there will be any 
impactful weather during these periods.

&&

.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 509 AM CST Wed Jan 29 2020

North Dakota sites...MVFR cigs this morning will trend toward IFR by 
18Z and remain IFR through majority of 12Z TAF period.  Areas of 
light snow or freezing drizzle possible around and north of DVL/GFK. 
Dense fog at airfields vcnty of DVL through 18Z.  Southerly winds 
expected to shift to westerly component this afternoon.

Minnesota sites...early morning VFR cigs will become MVFR by 
18Z...remaining MVFR throughout the afternoon and become IFR after 
sunset. Areas of light snow and possibly freezing drizzle possible 
this afternoon.


&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...Dense Fog Advisory until noon CST today for NDZ006-007-014-015-
     024-026-028-029-038-049-052-054.

MN...None.
&&

$$

UPDATE...Speicher
SHORT TERM...Speicher
LONG TERM...DJR
AVIATION...Speicher