179 
FXUS63 KFGF 081151
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
651 AM CDT Fri Jun 8 2018

.UPDATE...
Issued at 651 AM CDT Fri Jun 8 2018

Only minor adjustments during this update. Radar trends upstream
still not showing shower activity holding together, but short
range models still support increasing coverage through 18Z, so I
held off on downward adjustments. Degree of daytime clearing,
moisture return, and warm front position are all factors we will 
be monitoring for main severe threat this afternoon. Better 
clearing/moisture return may support a limited risk further north 
even if shear ends up weak. 

&&

.SHORT TERM...(Today and tonight)
Issued at 422 AM CDT Fri Jun 8 2018

Broad ridging continues across the central US, while shortwave 
troughs propagate through southwest flow into the Norther Plains.
Surface pattern supports east to southeasterly flow over our 
eastern CWA, with a stronger southerly component further west. Mid
level energy this morning is tending to split with one vort max 
tracking through southern Canada and a second associated with MCS 
in South Dakota. General trend on radar lowers confidence that 
shower activity will make it into our CWA early this morning, but 
as these two mid level impulses track eastward there could be just
enough lingering forcing between these features through this 
afternoon that showers could begins to fill in at track eastward 
over our area. Instability is currently very limited, however 
diurnal heating should allow for an increase in ML CAPE supportive
of possible thunderstorms development. 

A stronger shortwave moves along the South Dakota border late this 
afternoon and overnight, and a warm front should lift to the edge of 
our far southern CWA. This would be where any severe threat would be 
favored late afternoon/evening as the change in air mass (increasing 
ML CAPE) and favorable shear profiles near the frontal zone could 
support super cell development. Severe coverage and a limited window 
when parameters line up lower confidence even in our south where best 
chance for severe would be. CAMs support increasing shower and 
thunderstorm coverage further north where instability and shear are 
much less favorable, and forcing may not be as organized as precip 
signal implies (much less organization to shortwave further north). 
Lingering shower/thunderstorms activity would tend to transition 
eastward over our CWA through the night (where it does develop).

.LONG TERM...(Saturday through Thursday)
Issued at 422 AM CDT Fri Jun 8 2018

Thunderstorms are still expected Saturday with best chances in the 
earlier part of the day, possibly as a continuation of overnight 
convection from Friday. Better chances for morning showers and 
thunderstorms will reside within Minnesota. Later in the day, it is 
probable that mostly dry conditions will develop as the region sees 
a lull in shortwave passages within the upper ridge flow. However, 
there is still some weakly capped instability over portions of North 
Dakota as moisture advection still resumes. So should any un-
forecasted shortwave sneak its way through the flow during peak 
heating, some isolated or widely scattered pop-up afternoon 
thunderstorms could ensue aided by slight orographic influences such 
as the western edge of the Red River Valley.

The ridge axis finally pushes eastward allowing for a strong upper 
trough to break out of the Pacific Northwest into the Northern 
Plains by Sunday. As a result, a seasonably strong cold front is 
expected to move through from the west late Sunday into early 
Monday. Strong forcing and the steady progression of the cold front 
will allow for thunderstorm development to last through Sunday 
overnight. While some storms could be strong with gusty winds and 
heavy rainfall, better severe parameter spacing will remain to the 
west and south, not to mention timing currently progged to occur 
overnight. Still, should the cold front be delayed to move through 
later into Monday, the chance for severe chances could increase. 
Confidence in this happening is low though. Gusty winds are expected 
on either side of the cold front Sunday and Monday with Sunday 
likely being the last day of above normal temperatures.

Behind the cold front a much cooler airmass will mean less 
thunderstorm chances and cooler temperatures towards normal or 
slightly below normal. As the well developed upper trough moves 
through Canada, limbs of vorticity and surface troughs rotating 
around the trough will allow for shower chances early next week. 
Differences in the remaining development of this upper trough 
between models begin to grow considerably towards mid next week, 
although consensus is to break the trough down while moving it 
eastward into late next week. The residence time of the upper low 
will also influence how long breezy winds linger through the
region.

&&

.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 643 AM CDT Fri Jun 8 2018

VFR conditions should prevail through the TAF period. Southeast
winds should increase to 12-15kt with gusts around 20kt this
afternoon decreasing early this evening. Showers and thunderstorm
activity should increase in coverage this afternoon and evening
transitioning eastward overnight. Coverage is a question,
particularly with thunderstorms, so I limited mention to VCSH 
during most favored periods in the afternoon/evening. 


&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
&&

$$

UPDATE...DJR
SHORT TERM...DJR
LONG TERM...CJ
AVIATION...DJR