Sunday, July 22, 2012

Forecast for Monday, July 23, 2012

A general increase in clouds can be expected this evening across our region. I am currently watching for the development of thunderstorms in the Great Lakes vicinity through the evening hours. Some of the model guidance over the past 48 hours has been hinting at the potential for a MCS to develop and move southeast. Any MCS upstream, depending on where it exactly develops, could at the very least scrape the northern half of our area in the overnight and early morning hours of Monday. Should an MCS occur, the cluster of thunderstorms may produce some hail and gusty winds. Besides this cluster of storms, it would just otherwise be a mostly cloudy overnight and early morning. Convective inhibition and a cap may hold strong though and may tear apart any MCS that does develop anyhow. I am not too enthusiastic about our thunderstorm chances in the overnight hours at this moment, but there is a little room/narrow window for something to pop.  A lot of dry air also remains in place (hence the comfortable day we have been having) and while dew points should rise is hard to find much moisture for a good MCS. We will continue to monitor and see the post Tom wrote below for what exactly model guidance is putting out there.  

Meanwhile, later on Monday, there is a threat for afternoon and evening thunderstorms as a result of possible destabilization ahead of a weak cold front that should move into the region. Should the earlier MCS be decent in strength and cover portions of the area, it may not allow for the atmosphere to recover in time for the second triggering mechanism in the afternoon and early evening hours. The MCS may fizzle as well in the overnight hours, if it develops at all, but cloud debris may also inhibit some of the instability from the developing if those clouds can keep the temperatures down some. Therefore, the extent of afternoon and evening convection is unclear at this time…but at least scattered thunderstorms are possible. Where thunderstorms develop, some could be strong to severe. Temperatures, even with the clouds, have a good shot at reaching into the upper eighties. If there is more sun than clouds, lower nineties are possible. We are in a “see text” or 5% risk of severe thunderstorms on Monday in the Storm Prediction Center Day Two Outlook.

There is the potential for another MCS late Monday Night or early on Tuesday Morning. Yet again, there are questions as to whether this will develop. Conditions may be more conducive for the development of one and the survival of one by this time frame. Yet again, what effects this MCS will have on temperatures and instability ahead of a stronger front timed for later on Tuesday is unclear at this moment. There could once again be at the very least additional scattered, strong t-storms on Tuesday.

The bottom line is this. Expect a period or two of thunderstorms in your neighborhood Monday and/or Tuesday, although some places may miss out on all chances by the end of Tuesday. Any thunderstorm may produce gusty winds, hail, and frequent lightning where they strike. The more sun we see, the better the chances to hit or slightly exceed 90 degrees. Flash flood guidance is still relatively high for most of the area, so we can handle some heavy rain, unless we see some substantial totals. 

Wednesday and most of Thursday looks to be partly to mostly sunny at this time. Late on Thursday, a warm front will approach the region. There could be some increasing cloudiness with the chance of showers. By Friday, this warm front is expected to pass through our region. How fast it does so is in question. Eventually, a cold front will be sent into the region during the weekend. There could be a hot day or two with high humidity prior to the cold front passage. Hopefully I am not being too optimistic and premature, but it does appear that we may be starting to cool off just a bit from where we have been for several weeks now.