When I stepped outside at 5 am this morning the temp was a summer-like 68° which is above the normal high temp for a mid-October day. We didn’t make 80° yesterday but we did rise to a pleasant 78° with an overnight low of 62°. After a few early morning light showers, we saw some clearing late in the day. Our rainfall was .06 of an inch which brings us to 1.68 inches for the month.
I suspect today may be our last run at 80° for the year though with the CPC guessing above-normal temps for the rest of the month upper 60s and low 70s is not out of the equation.
The SPC has moved the slight risk area for storms further west again:
- Warmest day the rest of this week is TODAY With the strong fall storm cominig through the area today, we will have deep mixing. That will cause it to be breezy and allow our afternoon temperatures to reach near 80 degrees over most of our CWA. Temperatures this warm will likely not occur again the rest of the month. It seems to this forecaster we are now seeing some significant changes to the longwave pattern over North America. That will result in cooler temperatures next week. I am still not thinking anything really cold, just a return to near normal. We currently have a deep western trough and eastern upper ridge over the CONUS. Currently there is a strong zonal jet crossing the north Pacific above 50N. This continues to load the western trough over the past week with shortwaves through this week. That upper air pattern has given us a series of storms, the one today is just one of these systems. We have one more to go, late in the week. By the end of this week, a system coming off eastern Asia (China and Russia) is strong enough to buckle the flow so it will no longer be zonal over the north Pacific. That causes the Western trough to retrograde off shore into the eastern Pacific. That in turn retrogrades the eastern upper ridge which will be replaced by a developing eastern trough. This retrogression of the upper wave pattern over the northern hemisphere will start bringing colder air south into this area with a series of cold fronts next week. So, if you have been enjoying this unusually warm weather for mid October, you have the rest of this week, then what would be more typical finally for mid to late October will come into Southwest Michigan. That would be highs in the 50s and 60s and lows in the 30s into the 40s. - Stormy evening / mostly west of US-131 We are still expecting strong to severe thunderstorms this evening as previous recent discussions have suggested. However, as we get closer to the event more details become clear. In this case it now seems the severe threat is mostly near and west of US-131 late this afternoon into early this evening (see SPC Day 1 disccusion). We will get two lines of storms coming through this area, this evening. It is the first line, late this afternoon into early this evening that will have the strong storm. The second line early tonight will likely be mostly just rain showers. The first line of storms is associated with the upper level jet core, crossing this area. That line will have decent instability (1500 to 2000 j/kg of MU cape) to work with and there is a 30 to 35 knot low level jet (near I-75 actually) and 35 to 40 knots of effective deep layer shear helping the cause. This is the line that will have strong to severe storms with it. As was pointed out in prevoius discussions, it will have unidirectional speed shear with it. We expect linear storms to be the primary storm mode. However we do have a problem with this event. The system at mid and high levels will be weakening as it moves into the area toward evening. The jet core from 500 to 300 mb loses around 20 knots of wind between 8 pm and 11 pm. Also the MU/ML/Surface based capes all plummets as this is happening. Also the jet`s left exit region lift area is over our CWA at sunset but it is over Northwest Lower Michigan by 11 pm this evening. That will cause mid and high level subsidence behind it . That would mean mid level sinking air late this evening over our CWA. All of this leads me to believe, and this is shown by all of the high resolution models, that the strongest storms will be early this evening over the western CWA. Those storms will struggle to get east of US-131 before 10 pm. Mostly because they will be tracking north northeastward. By the time they would get east of US-131 the instablitiy will largely be gone. Hence the real severe storm threat is near the lake shore late this afternoon into early this evening. Expect individual storms to be racing to the north northeast around 40 to 50 knots this evening. Some large hail is possible under the stronger updrafts as there is 400 to 600 j/kg of hail cape and mid level lapse rates are near 7c/km. Damaging winds are possible from those stronger storms too. An isolated QLCS tornado is not out of the question. The storms will be moving fast but rainfall may still locally be has high as a 0.75". The highest amounts are expected to be near US-31 north of Holland. It would seem the flooding threat is fairly low since the storms will be moving so fast. The second line of storms is caused by upper trough coming through. That has the best low level jet support (40 to 50 knots) but there is very little cape left for that line to work with. Also we have the issue of upper convergence (above 700 mb) which will not be overly storm friendly. So that second line will happen but it will be much weaker since it will lack strong cape to help it`s cause. This system is a decent upper level closed low that is being kicked northeast by a much stronger upper wave downstream of it. It will remain a cutoff low through Tuesday. That means we will be in the cyclonic wrap-around flow of it into mid afternoon on Tuesday. That will mean showers (mostly rather light) during the day time on Tuesday. - Brief break in stormy weather Wednesday We get a brief break in the stormy weather Tuesday night into Wednesday morning. That is thanks to a shortwave ridge between the departing system and the incoming much larger system. This next system is a little more complex then that previous three system we have seen since early last week. This will mean some clearing Tuesday night but once again, there is not a lot of cold air behind this system so lows will only be in the 50s, which is around 10 degrees warmer than normal. Wednesday will start off sunny but clouds will move in by afternoon. Highs should get into the lower 70s even so. - Showers Thursday into Sunday and turning cooler That 140 to 150 knot jet core crossing the Bering sea will be the will force the western trough east and bring us a prolonged rain event. As that jet digs into the western trough it forces another strong fall storm to deepen and race north toward the Canadian border over eastern North Dakota late Wednesday. That pushes another warm front/cold front event at us. We will get showers from the warm front and the cold front. However, that 150 knot jet creates another system. That causes a wave on the cold front even as is coming through the area just south of us by Friday. That surface low heads toward Michigan bringing rain for Saturday. This time through there is COLD AIR! So we then get lake effect rain showers and it turns colder (really near normal) by Sunday into Monday. I do believe we will see SOME rain every day (midnight to midnight) this week in our CWA. Tonight, western sections will have the heaviest rainfall of the week. It could be really wet here through Thursday/Friday/Saturday depending on the track of the surface low and how the warm front passage plays out.