Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/21/19

Area Forecast Discussion
National Weather Service Marquette MI
634 PM EDT Sat Apr 20 2019 .SHORT TERM...(This evening through Sunday) Issued at 411 PM EDT SAT APR 20 2019 WV imagery and RAP analysis indicated a mid/upper level ridge from the southern Plains to the northern Great Lakes between lows over Hudson Bay and OH/KY/WV. A shortwave trough sliding through northern Ontario was dragging a cold front into northern MN. Otherwise, southerly winds and sunshine ahead of the front pushed temps into the mid 60s over most of Upper Michigan. However, lake breezes have dropped temps into the 40s and 50s along the Great Lakes. Tonight, as the front continues to sag into Upper Michigan, increasing 800-600 mb fgen behind the front is expected to support a band of rain from ne MN into wrn Lake Superior and portions of west Upper Michigan, mainly after 06z. Enough spread remains with the short term high res models and SREF so that only chance POPs are included with the highest chances into the northwest. Sunday, the front will slowly drop through the rest of Upper Michigan with the stronger fgen and higher pcpn chances lingering over the northwest half. Otherwise northeast winds and clouds will spread into the area. A strong north-south temp gradient near or behind the front will result in highs in the mid 40s north and mid 60s south. .LONG TERM...(Sunday night through Saturday) Issued at 359 PM EDT SAT APR 20 2019 The main focus of the long-term is the potential for a prolonged moderate, to at times heavy, rain event Sunday night into Tuesday morning. It is not out of the question that some locations could see upwards of 1-2`` of rain. Given the antecedent conditions (saturated soils, snowmelt already causing elevated flows/levels on rivers, and areas across the Keweenaw Peninsula and far eastern Upper Michigan that still have 8+ inches of liquid water within the snowpack), the potential for this persistent, heavier rain causes concern for additional and worsening of ongoing flooding issues. Did issue an ESF to highlight the potential hydro issues coming up, but this will need to be closely monitored into early next week. Sunday night through Monday, a weak cold front is progged to stall across the region as shortwave energy begins to lift northeast towards the Upper Mississippi Valley and warm air advection returns northward. Along this stalled front, a strengthening baroclinic zone aloft, PWATs pushing 1+ inch, and warm cloud depths approaching 8- 10k feet will aid in additional lift/support for a focused area of heavier rain. Initially, the main area of concern looks to be across western Upper Michigan Sunday night into Monday morning. As the above mentioned baroclinic zone slowly pushes eastward Monday into Tuesday and mid-level impulses lift across the area, rain will become widespread and gradually shift eastward across central and eastern Upper Michigan. Another concern is the potential for training precipitation into Tuesday morning due to parallel mid-level flow across the baroclinic zone. This may lead to enhanced rainfall totals in spots. Models aren`t in good agreement with the shortwave trough progged to dig south across the Upper Mississippi Valley on Tuesday, finally giving the pesky baroclinic zone the push it needs to vacate the area. Therefore, confidence isn`t high in regards to when precipitation will come to an end during the day on Tuesday. However, by Tuesday night the above mentioned shortwave will continue to dig south across the region, ushering in post-frontal high pressure and a brief period of dry conditions for Tuesday night and Wednesday. Towards the end of the week, a quick moving shortwave will push a weak cold front across the Upper Great Lakes, bringing another chance for rain on Thursday. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 634 PM EDT SAT APR 20 2019 VFR conditions will continue through tonight. Some showers will begin moving in at IWD and CMX toward daybreak on Sunday, but MVFR conditions at IWD and CMX should hold off until mid morning Sunday and at SAW by late Sun afternoon. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 411 PM EDT SAT APR 20 2019 Northeast winds of 20 to 25 knots are expected on the western end of Lake Superior Sunday. Otherwise, a quiet stretch of weather will continue as winds remain below at or below 20 knots into much of next week. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...JLB LONG TERM...Ritzman AVIATION...07 MARINE...JLB