LIVING ON THE EDGE...
The next few days will be tricky ones to forecast as my area resides on the northern edge of the storm track. That's a precarious place to forecast as both precipitation and temperatures will be highly dependent on the position of a boundary that vacillates north and south through the weekend. If the placement is off just 50 miles (not much in the weather world) that could make the difference between stormy conditions or quiet ones depending on your location.
Challenges abound as early as Friday due to a warm front which lifts into southern Iowa. North of it clouds will be prevalent and the remnants of overnight showers and storms may flirt with this part of my area during the day. Abundant clouds and at least scattered showers and storms will likely make for a crummy day in the north. Further south, much of the day ends up dry and muggy with dew points well into the 60s. The EURO indicates temperatures that look like this at 5:00pm Friday.
Here's those muggy dew points kicking up a little steam down south where readings are in the low 80s.
Friday night and Saturday the warm front only inches north which in terms of sensible weather means little change. Very warm muggy conditions will remain across the south Saturday with the best chances for rain over the north half (near and north of the boundary) which arcs from NW to SE somewhere close to I-80. The temperature forecast is shaky, especially up north with the EURO showing a range from the mid 70s around HWY 20 to the mid 80s south.
With all the moisture that's available, there will be instability...CAPE on the HRRR is sufficient for strong to perhaps severe thunderstorms Saturday afternoon or evening.
Shear should be most favorable near the warm front and could very well generate some rotating updrafts. While hail and wind would be the most likely concerns, there is at least a small contingent tornado threat where destabilization is maximized. SPC has a slight risk outlook in place for the potential focused on the heart of my area.
Saturday night any thunderstorms that fire will have ample moisture to work with meaning heavy downpours are a distinct feature to watch for. Not knowing the mesoscale details which will be in flux on a daily basis makes it hard to pinpoint the heavy rain swaths. An obvious spot to focus on is near and north of the warm front where lift is prominent and some training is possible. Steve Gottschalk my folklore expert tells me the ants are making tall hills again. The old timers say that means heavy rains. Here's what models are suggesting for rainfall through Sunday.
The EURO
The GFS
The 3k NAM
The 12K NAM
Sunday (Mother's Day) things really go downhill in the north with the passage of a stout cold front early in the day. Temperatures may not get out of the 50s with a brisk NE wind. Very raw! The chill does not reach the far southeast until early afternoon. Before it arrives highs could get back around 80. For sure there is going to be a drastic thermal boundary from north to south with the EURO showing 54 in Dubuque and 82 in Keokuk at 1:00pm Sunday afternoon.
CONSIDER A STAY AT ONE OF THE MOST UNIQUE ACCOMMODATIONS IN THE MIDWEST...
A LATE SPRING CHILL IN OUR FUTURE...
Monday through the day Thursday look quiet. Readings will start cool before a quick warm-up Thursday ahead of another strong cold front. After highs near 80 Thursday, maximums will likely stay in the 60s Friday through Sunday of next weekend. The GFS actually shows lows in the upper 30s in the north the morning of Saturday May 20th. I still wonder if guidance is a bit over done with the amount of cold air. I'm hoping future runs back off a bit with the intensity. That is possible considering the strength of the May 20th sun and the fact days start getting shorter in about a month. Isn't that a shocking revelation.
Well, that's all I can dig up for you today. Enjoy whatever it is you enjoy this weekend and by all means, roll weather...TS
