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000
FXUS63 KDVN 140820
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
320 AM CDT Sun Apr 14 2024

.KEY MESSAGES...

- Well above average temperatures will be seen once again today and
  Monday, with highs in the upper 70s to lower/middle 80s today

- Lots of sunshine today and most of Monday remains on tap

- Chances of thunderstorms return Monday night through early Wednesday,
  with potential for severe weather late Monday and Tuesday

- Expect a cooldown for the latter part of the week, with temperatures
  returning to near seasonal averages. A few chilly nights are
  expected by next weekend.

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 318 AM CDT Sun Apr 14 2024

If you enjoyed yesterday`s warmth, then you`re in luck as there is
more where that came from! Despite a weak front that will sweep
through the area later this morning, temperatures are expected to be
even warmer than they were yesterday (by as much as five degrees in
some locations)! Thanks to lots of dry air in place, abundant
sunshine is once again expected, with highs in the upper 70s to
lower/middle 80s, warmest across our south.

Conditions remain dry tonight and Monday, with temperatures
continuing to be well above average. Highs on Monday will be
similar to what they were Saturday, warming to the middle 70s
north to the lower 80s south.

If you have any outdoor plans today, it looks like a great day for
them. Just make sure you bring your sunscreen if out for a
while!

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 318 AM CDT Sun Apr 14 2024

Global and ensemble guidance continues to paint an active period in
our forecast area Monday night through at least Wednesday morning,
as a large system develops over the central Great Plains. There has
been very good run to run consistency among the models, which
continues to show a cut-off upper-level low translating eastward
just north of the Four Corners region by Monday afternoon. Surface
low pressure will develop via lee cyclogenesis, and confidence is
high it will move northeastward towards the eastern NE/southeast
SD/western IA region by Tuesday evening per both the GEFS and ECMWF
ensemble low tracks. A warm frontal zone will develop ahead of the
surface low and lift northward into our area. This system appears to
have strong dynamics with it, given a central pressure ~986 mb,
which per the NAEFS is in the bottom one percent of climatology.
Additionally, a 110+ kt upper-level jet and a 40 to 50 kt low-level
jet will both be impinging on the warm sector in our area as the
surface low approaches on Tuesday. With generally low to moderate
instability in place, this will set the stage for at least a few
rounds of thunderstorms in our area, some of which is looking more
likely to be strong to severe. Let`s break things down by time:

1) Monday night/Tuesday morning

A warm frontal zone will lift northward into our region as the
surface low approaches. Convective initiation appears to be around
or after sunset Monday evening. As we head into the overnight hours,
spatial coverage of convection appears to increase with time. Most-
unstable CAPE from the GFS, NAM, and GEM guidance all paint a
corridor of instability on the order of 500 to 1500 J/kg, with a
sharp gradient in instability. Soundings indicate that elevated
convection will be most likely, so there is the threat for some
elevated hailers associated with the warm front. For this threat,
SPC continues to outline a Marginal Risk (level 1 out of 5) for
areas along and south of a Belle Plaine, IA to Industry, IL line.

2) Tuesday afternoon and evening

This is the more concerning period for severe convection, especially
as the surface low approaches the area with the stronger kinematics
and a pronounced mid-level impulse moves into the area. With the
anomalously strong low-level jet, clockwise-curved low-level
hodographs, and steepening mid-level lapse rates around 7 to 8
degrees C/km, large hail and tornadoes appear to be the primary
threats with this convection. Additionally, the deep-layer shear
profile will be strong, with bulk shear magnitudes of 40 to 50
knots. Confidence in the threat for severe storms has increased with
this forecast package, which has been depicted nicely in the CSU
machine-learning severe probabilities. SPC has introduced an
Enhanced Risk (level 3 out of 5) for severe weather for areas along
and west of a line from Belle Plaine, IA to Mediapolis, IA to
Stillwell, IL. There remains a Slight Risk (level 2 out of 5) across
the remainder of the forecast area.

There does still remain some uncertainties on how things will play
out, such as how the convection Monday night/Tuesday morning will
influence the convective potential later on in the day Tuesday, as
well as how much destabilization will occur in the wake of the
Tuesday morning convection. Stay tuned for more details as they
become available.

Tuesday night and Wednesday will remain active as the area of low
pressure gradually moves off to the northeast. Chances of showers
and storms will remain with us, but the threat for severe weather
looks to wane late Tuesday and Wednesday as the stronger jet
dynamics shunts off to the east. Eventually, dry conditions will
return for the second half of the week. There may be another
shortwave to move through on Thursday and bring another round of
showers to our area.

As the Tuesday system departs, expect a return to more seasonal
temperatures by Thursday, with highs in the middle to upper 50s. A
couple of chilly nights are possible for next weekend, with lows in
the 30s across the area. The CPC favors below normal temperatures
after midweek and into the weekend.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1224 AM CDT Sun Apr 14 2024

VFR conditions will continue throughout the TAF period. Ongoing
low-level wind shear was observed on the DVN VAD wind profiler,
thanks to a 40 to 50 knot southwesterly low-level jet in place.
The LLWS will continue through around sunrise before weakening.
While winds today won`t be as breezy as they were yesterday, a
weak front will move through this morning and turn winds more
from the southwest early this morning to a northerly direction
by noon today. Sustained winds will be around 10 knots across
the area.

&&

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

&&

$$

SHORT TERM...Schultz
LONG TERM...Schultz
AVIATION...Schultz