Area Forecast Discussion
Issued by NWS Grand Rapids, MI
Issued by NWS Grand Rapids, MI
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857 FXUS63 KGRR 261445 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 1045 AM EDT Fri Apr 26 2024 .KEY MESSAGES... - Occasional showers and storms tonight through Monday - Briefly Dry Tuesday, then Additional Showers Wednesday/Thursday && .UPDATE... Issued at 1045 AM EDT Fri Apr 26 2024 Nothing to really update for the forecast this morning. We will see elevated Fire Weather conditions through much of the day with a dry air mass in place/drier air mixing down, and somewhat gusty winds developing. With the recent rain earlier this week however, conditions should not get out of hand. The aforementioned dry air will delay rain showers moving in later today a bit at the onset. There does look like a small chance of a few will arrive for the SW corner of the area prior to the end of this forecast period. Thunder does not look possible until we approach midnight, and thereafter. && .DISCUSSION... Issued at 353 AM EDT Fri Apr 26 2024 - Occasional showers and storms tonight through Monday A ridge aloft will slide eastward today and allow a weakening upper shortwave to move into Minnesota tonight. At the surface a warm front will move into the area tonight. Surface dew points tonight will surge into the 50s tonight with MUCAPE values increasing to around 500 j/kg late. Today will mainly be dry with a lowering and thickening cloud base ahead of the warm front. Tonight, showers and a few storms are expected as the instability increases overnight. Not expecting any strong storms given the lack of instability associated with the nocturnal minimum. Saturday we will be in the warm sector of the system as it weakens and moves into Canada off to our north and west. We are in the day 2 SPC outlook with a slight risk for areas to the north and west of Grand Rapids. We certainly could see some warm sector convection on Saturday, but this looks to be scattered and relatively low chance. What convect we do see in the day 2 period would likely come Saturday night as upstream storms and the associated cold front sag in from the northwest. Given bulk shear Saturday night is near 40 knots over Central Lower and MUCAPE values will be in excess of 1,000 j/kg cannot disagree with a threat of some severe weather, but overall feel our chances are not great. Main factors that would lead away from severe weather Saturday night are a low level jet that is forecast to weakening as is the system to the west. We will obviously be monitoring for severe weather both Saturday afternoon and night, but feeling is it may not be a slam dunk event. Chances for showers and storms continue Sunday into Monday as another plains upper shortwave works northward into Canada. We will again be downstream of the better activity most likely but the warm and showery weather will continue. Best chances in this time frame will likely be Sunday afternoon on the warm front across Central Lower Michigan. Day 3 only has us in general thunder from SPC and cannot argue with that. Highest rainfall totals from this weekend into early next week will be west of Lake Michigan where the deeper moisture and more importantly stronger dynamics will be in play. We are still looking at solid rain in our area though through Monday night however on the order of 0.50 inches towards Jackson to 1.50 inches up near Ludington. If we see any hydro issues at all it will likely be to the north of the Grand River basin up along the Muskegon and Pere Marquette. Given the totals we are forecasting though over multiple days we think the rivers will be able to handle it. - Briefly Dry Tuesday, then Additional Showers Wednesday/Thursday A break in precipitation is expected Tuesday as brief weak ridging moves in place. Conditions turn active with showers Wednesday and Thursday as a cold front associated with an upper shortwave dives into the region. An 850mb thermal trough falls into the region late in the week leading to cooler temperatures starting Thursday. Summer- like temps in the 70s through the first half of next week will fall into the low 60s Thursday and Friday. && .AVIATION /12Z TAFS THROUGH 12Z SATURDAY/... Issued at 753 AM EDT Fri Apr 26 2024 A warm front will lift our direction from the Plains states today and move into the area tonight. As is the case normally with warm front, ceilings will lower and thicken over the next 24 hours. Ceilings will remain VFR today, but become MVFR tonight between 02Z and 05Z. At the same time rain showers will spread in. A few thunderstorms will be embedded as well, especially late in the night. 3-5SM / MVFR visibilities are likely after 05Z as well. Winds will be gusty from the southeast both today and tonight. 10-20 knot wind speeds are likely with gusts into the 20-25 knot range. && .MARINE... Issued at 353 AM EDT Fri Apr 26 2024 Will hold off on any marine headlines with this morning`s forecast package. That said, we may need marine headlines as we head into Saturday in strong southerly flow. Strong warm air advection this time of year though is always troublesome given the inversion that develops. Strongest winds will flow over the cold dome near the surface and never make it down to build waves. Today, winds are offshore (southeast) and more in the 10-20 knot range. Winds tonight will begin to ramp up and we could need a headline for winds alone, but given short fetch (southeast/off shore) and mixing to the surface concerns will hold off. NAM 3km Bufkit winds are suggesting solid SCA conditions on Saturday if not Gales. We will hold off for now and take another look today at any potential headlines. A prolonged period of stronger south winds will exist from Saturday right through the day on Monday. Feeling is at least some of this will struggle to make it to the surface. Areas of fog may also be an issue Saturday-Monday as higher dew point air will be advected out over colder water which is usually a set up for instant fog on the Great Lakes in the spring of the year. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ UPDATE...NJJ DISCUSSION...Duke/Thielke AVIATION...Duke MARINE...Duke