524
FXUS63 KDVN 231114
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
514 AM CST Sun Feb 23 2025

.KEY MESSAGES...

- Our warming trend continues today, with highs around 40
  northeast to the lower 50s southwest; even warmer come Monday
  and Tuesday

- A few systems look to bring chances (20-50%) of light precipitation,
  in the form of rain, to our region Monday night and again
  Tuesday night into Wednesday

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 223 AM CST Sun Feb 23 2025

Southerly return flow around a large area of high pressure over the
southeastern CONUS will keep the warm air advection coming today.
Some high-level cloud cover this morning from a passing mid-level
shortwave will gradually move out of the region by mid-day today,
which will help temperatures climb once we clear out. Over the last
few days, guidance has been a bit on the low side compared to
observed temperatures, so we went a bit higher on today`s highs -
closer to the 75th percentile of the model spectrum, which results
in highs around 40 northeast to the lower 50s southwest. Helping
increase confidence in these temperatures, the 23.00z HREF ensemble
dew point temperature output indicates warming to above freezing
today for most locations, which should help accelerate the melting
of our existing snowpack. I suspect that the more snow we melt, the
more efficient we will warm up. We lost a good bit of snow
yesterday, and we should only accelerate this loss today and over
the next few days.

Cloud cover should build back in tonight as another wave moves in,
as well as continued southwesterly flow. With this being said, I`m
not as confident in the fog potential for tonight as I was a few
nights ago. Despite the melting snowpack, which should add extra
moisture to the boundary layer, elevated winds should help maintain
mixing and help to inhibit fog development. However, some of the
high-res global models and ensembles still show a potential for some
noticeable fog tonight, with the HREF ensemble probabilities of 2
mile visibilities between 30 to 50%, so not a great chance, but
still something to keep an eye on. The set-up doesn`t appear ideal
for fog, but if winds do end up going lighter, then some fog can`t
be ruled out. If we do have fog, soundings suggest it could be more
shallow and closer to the ground. Tonight`s lows look to dip to the
lower 30s for most locations.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 223 AM CST Sun Feb 23 2025

The warming trend really kicks into overdrive Monday and Tuesday.
The GEFS and ECMWF ensemble means for 850 mb temperatures by 12z/6
AM Monday both show values in the 7 to 10 degree C range (warmest
over our southwest). These values would be around the 90th
percentile of the ECMWF ensemble 850 mb temperature percentiles and
the SPC sounding database! We`ve maintained temperatures closer to
the 75th percentile of the model spectrum for Monday and Tuesday,
which suggests highs in the upper 40s to middle 50s for most areas.
We could even see some upper 50s to near 60 over our southwest on
Tuesday! We can`t rule out some fog due to this melting snow again
for Monday night, but if winds remain elevated, combined with cloud
cover, this might be tough to come by.

We continue to keep an eye on a few waves sweeping through the area
on the northern edge of the upper-level ridge that could affect the
area Monday night and again Tuesday night into the day on Wednesday.
Thermal profiles indicate that these waves could produce just rain
across the area. NBM has chance PoPs (20-50%) for each of these
waves, slightly higher for the Tuesday night/Wednesday system.
Overall, QPF appears to be light as these are mainly clipper systems
with limited draw of moisture from the Gulf. The previously
mentioned system for Friday night appears to be more moisture-
starved, with the bulk of the QPF remaining north of our area, and
this is reflected in the latest NBM.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 514 AM CST Sun Feb 23 2025

VFR conditions continue throughout the TAF period. Some mid- to
high-level clouds continue to sweep through the area, with
ceilings generally around 10 to 15 kft. Eventually, these
clouds will dissipate, leading to a period of sunshine before
another round of high clouds moves in this evening/tonight.
Southwest winds will continue through tonight, generally around
5 to 10 knots. Some strengthening flow aloft should support a
period of low-level wind shear. Confidence is highest for DBQ
to see this LLWS, but TAF terminals farther south remain a bit
more uncertain.

&&

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

&&

$$

SHORT TERM...Schultz
LONG TERM...Gibbs/Schultz
AVIATION...Schultz