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