FXUS63 KDVN 190806
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
306 AM CDT Sun May 19 2024

.KEY MESSAGES...

- Active pattern through the long term with chances for strong
  to severe storms through Tuesday. Tuesday is the best day for
  severe weather in the next 5 days.

- Rises along area rivers and localized flash flooding will be 
  possible through midweek, especially on Tuesday.

- Well above normal temperatures continue through Tuesday,
  dropping to near seasonal values by the end of the week.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 252 AM CDT Sun May 19 2024

Today should remain dry for the most part, as winds continue to 
recover behind the cold front that passed through. A weak wave will 
pass through the area during the afternoon, with the bulk of the 
forcing north of the area. While some guidance bring hints of higher 
vorticity through the area, confidence in this resulting in any 
precipitation is low, as we will be lacking surface forcing and moisture
until late evening/tonight. Thus, we should see quite a 
beautiful and hot day once again, with temperatures in the mid- 
upper 80s. Dew points will be on the rise as well, with higher 
values pushing north through the afternoon as well. Thus, it 
will start to feel a little muggy, with this also being noted by
an increase in cloud cover. 

Tonight, a deeper wave will push through the area, with the vort max 
passing right through our area late. Given the increase in moisture 
through the day, sufficient moisture will be in place to get showers 
and storms late tonight. While we can see warm advection 
showers/storms pushing in from the south this evening, the best 
chances for precipitation will be well after midnight, moving 
in from the west. This will be the timeframe where the bulk of 
the forcing pushes in, both aloft and at the surface, with a 
cold front passing through once again. Guidance indicates the 
possibility for MUCAPE around 1000-2000+ at times tonight, 
which will combine with deep layer shear around 30-35 KTs. Thus,
there will be the potential for some more organized/stronger 
storms late tonight. Given lower shear, this does not give much 
confidence in widespread strong/severe. Rather, we might see 
some robust updrafts that have frequent lightning and some small
hail. Isolated large hail will also be possible, as midlevel 
lapse rates are more than favorable for some larger hailstones. 

There remains quite a bit of uncertainty with the potential for 
storms tonight, especially when it come to severe potential. 
Generally following/messaging the HREF, as this seems to get the 
best grasp on what much of the short term suite is giving. Latest 
trends in some models indicate the wave slowing down, which can 
largely place the precipitation chances on Monday morning, leaving 
tonight dry for the most part. With a moderate to strong LLJ moving 
in around 3-6am, collocated with a strong vort max, I would not be 
shocked to see some convection late tonight. As the previous 
forecast discussion mentions well, we will have an MCV pass through, 
which could lead to an enhancement in the shear, which could aid
in developing stronger convection. Also, as was seen in the 12z
HRRR, similar supercell structures exist late this evening as 
well in the 00z HRRR run. Granted, this is not the answer key, 
but rather giving us an idea that there is a chance for some 
stronger storms, earlier in the night. The SPC continues to 
highlight areas west of the Mississippi River in a Marginal Risk
(level 1/5) for severe weather tonight, highlighting that 
isolated hail risk. 

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 252 AM CDT Sun May 19 2024

Overview...

A very active pattern remains through the central US this week, 
which will bring plenty of chances for precipitation to the area. 
Will mainly focus on the first two waves in question, which are set 
to move into the area Monday and Tuesday. While much of the wave 
will move in Sunday night, which is discussed above, the vort max 
will continue to slowly push through the area Monday. After this 
wave passes, we do not have much time until the next wave pushes 
through, which will be Tuesday. This is the wave that has our 
attention, as it holds the potential to bring a bit of severe 
weather. Weak zonal flow and ridging will be seen Wednesday and 
Thursday, bringing a period of dry weather, with more waves to 
come at the end of the week and into the weekend. Have those 
umbrellas handy through the week! Monday and Tuesday will be the
warmest of the long term, with the remainder of the week in the
mid-upper 70s throughout. 

Monday...

Slow moving front from Sunday night will continue to push through 
the area Monday, with a broad vort max. While much of the near 
surface forcing will move out of the area, the upper wave passing 
through should give way to some remnant showers and storms into the 
early afternoon, especially north of Interstate 80. This, along with 
height falls associated with the next wave, will also give way 
to increasing chances for precipitation through the day Monday. 
Shear seems to be quite low though, which can be a limiting 
factor to the severe threat. Although, as was discussed prior, 
if we get another MCV to pass through, local enhancements to the
environmental shear will be possible. Thus, a few strong to 
severe storms will be possible. This is highlighted once again 
through a Marginal Risk (level 1/5) for severe weather, where 
all hazards will be possible through the day. 

Tuesday...

Now, we move onto the wave that has caught our attention. Tuesday, 
we will have quite the wave eject off of the Central Rockies, 
directed at the Mississippi River Valley. Strong vort max approaches 
the area in the mid-late afternoon Tuesday, with a strong LLJ set up 
ahead of it. Warm front will pass through the area early on Tuesday 
morning, which will bring a shield of showers and storms through the 
area. This should move out by noon local time, leading to some 
clearing skies and destabilization of the boundary layer ahead of 
the approaching wave. Not only will we see moderate to high 
instability, but the deep layer shear will also be much stronger 
than the previous days. Thus, we have moderate confidence in seeing 
organized convection. Some storms may be strong to severe as well. 
Being in the open warm sector much of the day, we will see the 
potential for some discrete storms firing up that afternoon and 
early evening. Although, this seems to be favored west of our area. 
These are expected to rapidly grow upscale, with a line of 
strong/severe storms being the main concern for our area that 
evening/night. As was mentioned prior, the strong LLJ will persist 
into the nighttime hours, aiding in the longevity of the storms. 
Combined with the severe threat will be the chance for heavy rain. 
Fortunately, storms should move in and out relatively quickly. 
Although, they will drop heavy rain. Currently, we are looking at 
PWATs between 1.50-1.75". This will favor the potential for 
localized flash flooding, as well as the chance to see more rises on 
area rivers. 

The SPC highlights our whole area in an Enhanced Risk (level 3/5) 
for severe weather on Tuesday and through the evening, with severe 
winds and a few tornadoes being the primary threats for our area. 
Large hail will be possible as well, but will be a secondary threat. 

Beyond...

Weak ridging and zonal flow will be seen Wednesday into Thursday, 
which will bring a brief period of dry weather. Friday and into the 
weekend, the pattern becomes active again, bringing more chances for 
precipitation. Much uncertainty exists, so we will refrain from
further details. Temperatures will be more seasonal through, 
with most in the mid-upper 70s. 

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1231 AM CDT Sun May 19 2024

VFR conditions will prevail through the TAF period, with
variable winds. A cold front is currently working through the
area, with winds ahead of it out of the southwest and those 
behind it from the north-northwest around 5-10 KTs. After 12z, 
winds continue to shift, becoming southeasterly around 18z. 
Otherwise, mostly clear skies will be seen through much of the 
forecast, with an increase in mid-high clouds after 18z as well.
Otherwise, no sig wx is expected at this time.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...None.
IL...None.
MO...None.

&&

$$

SHORT TERM...Gunkel
LONG TERM...Gunkel 
AVIATION...Gunkel