We have a temp of 37° this morning at 6 am with a few light showers trying to work themselves in off Lake Michigan. We have only had .29 of an inch of rain so far this month as we continue through our dry spring. The CPC is predicting a warming trend with a slightly better chance of seeing more persistent rain – they have been predicting higher than normal chances of rain since the beginning of the month so I would take that with a grain of salt.
On the other hand, most current models are now strongly hinting of a pattern shift coming from this weekend on into next week with warmer temps and better chances of rain closer to the one-inch range as they are showing the probability of tapping into the Gulf moisture a more reasonable assumption. We have a lot of ground to catch up on in the rain department.
-- Frost/Freeze Threat Through Wednesday Morning -- The setup for frost and freezing conditions tonight looks a bit better than this morning, with colder readings of 28-32 expected for the majority of the region (save for the western half of the immediate coastal counties). This will likely necessitate a Freeze Warning for most or all of our forecast area. Given a mid level shortwave dropping through tonight I would expect NW winds to hold up, making this more of an advective freeze as colder temperatures aloft advect in. Similar case for Tuesday night/Wednesday morning, though in both cases model soundings do indicate a low level temperature inversion. I think low temps will be very similar to tonight/Tuesday morning. In both cases I am still anticipating the core fruit belt region along our lakeshore should escape a hard freeze scenario. Further inland, it could be a close call. Take precautions as necessary through Wednesday morning, and then we may be out of this threat for good. -- Low Risk for a Sprinkle / Light Shower Today and Tuesday -- Given the robust mid level troughing (upper low near Lake Superior) and cold air advection over the Great Lakes today and Tuesday, can`t totally rule out a sprinkle or light shower developing. These would be minor and most places won`t get rainfall. Model soundings are indicating cloud bases would be rooted near 850 mb with plenty of dry air below, so virga may be a more likely scenario. -- Pattern Shift is Anticipated Next Week -- There is growing confidence in next week being warmer and wetter than we have seen recently. Normal highs by that time are around 70 degrees. It is looking likely that we`ll be near to above normal for temperatures. Ensemble guidance is also hinting at a wetter stretch setting up. The ECE mean 500 mb height pattern becomes more conducive to a wetter setup in the Midwest and Great Lakes. ECE mean precipitable water content makes a distinct upward jump by the end of this weekend and carries us all the way through next week potentially. We have seen numerous model runs now of this being projected. Also intriguing is the fact the deterministic runs of the GFS, GEM, and ECMWF indicate a more active LLJ by early next week that could have a fair shot of bringing up Gulf moisture into our region instead of being shunted south of here, as has been the case so often this spring. We`ll see how that pans out. Ensemble guidance from the ECE, GEFS, and CMC shows growing support for 1" or more of rain next week. The ECE probability of 1" or more across our region is 50%-60% with the GEFS and CMC showing 60%-70%, which is fairly impressive considering we are talking about the 7 to 14 day time frame. It is noted that roughly 1/3 of the ensemble members from the combined grouping of ECE/GEFS/CMC have 2" or more of rain. While these totals aren`t earth-shattering, they become noteworthy when you consider that we scraped together only 1"-2" of rain for the entire month of April. So, the bottom line is the odds are tilting toward a warmer and at times wetter period for us next week.