NOTHING LIKE A CHALLENGE...
Not that I wanted or needed one, but the weather this week has certainly provided me with a challenge. Thursday was the 4th consecutive day with rain in some part of my area and the streak will be extended several more days as the "ring of fire" pattern remains alive and well.
The challenge the pattern presents is determining when and where thunderstorm clusters are going to develop. Thursday evening three of these clusters were showing up from Minnesota into Iowa and Missouri. Each of these is associated with cold pools, outflow boundaries, or both. They are significant because they modify the environment around them and act as catalysts for additional storm development.
Models just don't have the ability to accurately identify where the associated mesoscale details are likely to set-up in a pattern such as this, especially beyond 24 hours. That leads to low confidence forecasts and situations where about all a forecaster can do is broad-brush a region and hope for the best. Not the way I like to do business.
The reason this is pertinent is the fact significant storms with heavy rains may impact my area early Friday. A brand new convective complex is in the formative stages as I write this and its hard to see the mesoscale details that result and therefore the overall impacts. The general idea is that an area of heavy rain will form somewhere over Minnesota and northern Iowa and then swing east southeast potentially impacting my northern counties Friday morning. In anticipation of this a flash flood watch was issued and remains in effect until 7:00 AM.
WPC also has the area under a slight risk of excessive rain.
If there are storms around Friday morning, (most likely across the far north) they are expected to dissipate by late morning or early afternoon. The convective debris will hold the key to how warm temperatures get during the day. Readings could be quite a bit cooler up around HWY 20 if clouds and rain are slow to clear. Further south, models are bullish on sunshine by afternoon and rapid heating. Highs here may approach 90 with heat index values in the upper 90s...very sultry.
Friday night another storm complex is expected but this time around it should be further north. Even so, there is the potential the cold pool could be stronger allowing storms to bleed into the far north but right now I'm thinking much of my area remains dry. You can also see WPC has moved the excessive rain risk further to the north.
The general forcing Saturday and Saturday night for additional storms looks to be far enough north that my forecast area stays dry, warm, and steamy. Highs Saturday should reach the upper 80s to near 90 with a heat index of 92-98.
Sunday, a front remains on track to arrive in the late afternoon or evening hours. With ample instability in place at least scattered thunderstorms are a good bet at that time. Some could be strong with locally heavy rain and water vapor pooled near 2.00 inches ahead of the front.
Last but not least, a significant hurricane (most likely a major...category 3 or greater) is looking more and more likely to impact the area from NE Texas through the state of Louisiana. The storm is due sometime Sunday and the GFS shows an ugly threat near or just west of New Orleans. This is far from certain but such a track as this would be a big problem for that area.
I guess I will leave it at that and the powers that be for what ultimately happens. Happy Friday everyone and roll weather...TS