199
FXUS63 KDVN 011745
AFDDVN
Area Forecast Discussion
National Weather Service Quad Cities IA IL
1245 PM CDT Fri May 1 2026
...18z Aviation Update...
.KEY MESSAGES...
- Frost Advisory in effect late tonight through daybreak
Saturday for much of the area north of a Kahoka, to
Burlington, to Princeton IL line. Steps should be taken to
protect any sensitive outdoor vegetation.
- Blocked pattern will maintain a general northwest flow across
the region for much of the period, with embedded waves and
fronts combining with diurnal instability/heating to produce
almost daily chances of precip in or near the forecast area.
&&
.SHORT TERM /THROUGH TONIGHT/...
Issued at 217 AM CDT Fri May 1 2026
An upper low was located over Ontario early morning with water
vapor imagery showing several shortwaves rotating around the
low and across the Midwest. One shortwave was shifting east of
the area early this morning with clouds and spotty showers
exiting owing to a brief bout of clearing. This has allowed
temperatures to drop off into the 30s in some locations, and with
diminishing wind could result in some patchy frost. However,
this frost potential looks limited and transitory as the next
shortwave upstream into NW Iowa is sliding E/SE with clouds quickly
approaching. Another wave was noted diving southward through the
eastern Dakotas. Overall, the DPVA attendant to the shortwaves will
foster increasing clouds today along with a chance for showers
(20-40%). Soundings show some elevated CAPE (100+ j/kg), which
could lead to some thunder with the low topped convection but this
should be fairly isolated with equilibrium levels warmer than -20c.
Highs look to be in the 50s, with some lower 60s possible especially
south where more solar insolation is anticipated.
Any showers should dissipate by mid evening, as the shortwave(s)
depart. Increasing subsidence in the wake of exiting system
and incoming weak surface high should bring about a decrease in
clouds. This along with light winds will make for favorable
conditions for frost, particularly north/west of a Burlington to
Princeton, IL axis, where confidence is highest on a longer duration
of clearing and weak winds fostering lows in the lower to mid 30s.
As a result, a Frost Advisory has been issued for much of eastern
Iowa, northeast Missouri and northwest Illinois. Can`t rule out
some cold drainage locations dropping to freezing or just below, but
this would not appear to be for a climatologically long enough time
to cause damage and necessitate a freeze warning. Still, anyone with
sensitive outdoor plants should take precautions to protect them.
Frost is possible south of a line from Burlington to Princeton, IL,
but confidence is too low for a headline at this time, as
probabilities for temperatures less than 36F are low due to the
potential for cloud cover to linger the longest in this area. Will
need to take a closer look today for any need on expanding the Frost
Advisory.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 217 AM CDT Fri May 1 2026
An omega block off the Pacific coast looks to remain in place throughout
much of the period. After a brief bout of westerly flow and moderating
temperatures near to above normal Sunday and Monday, we should see
a fairly persistent span of predominantly N/NW flow and cooler than
normal temperatures heading through mid to late next week. In fact,
per CPC days 6-10/8-14 temperature outlooks it appears this cooler
pattern will persist through mid-May with more frost/freeze conditions
possible, particularly around May 8th/9th. While some showery weather
likely at times no heavy rain is expected, and overall CPC has the
region favored for below normal precipitation. The NW flow should also
preclude any organized severe weather potential for the area as well
over the next 7+ days. That said there is a Marginal risk (level 1 of 5)
for an isolated strong/severe storm Sunday PM. Confidence is low
with this potential due to the presence of an EML and limited forcing
for ascent.
&&
.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1240 PM CDT Fri May 1 2026
Another upper level wave inducing sctrd mainly light showers
this afternoon and early evening, before moving on for a clear
out later tonight and into Saturday morning. An isolated
thunderstorm also possible especially south of I-80. Mainly a
VFR fcst, unless a passing shower manages to move right over a
TAF site and temporarily produce at least MVFR VSBYs and
possible MVFR CIGs. Generally light west to northwest sfc winds
or variable through most of the period. There is a chance for a
passing shower to produce a variable wind gust up to 25 KTs
through this evening. Saturday generally a VFR day through 00z
Sunday.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...Frost Advisory from 1 AM to 8 AM CDT Saturday for IAZ040>042-
051>054-063>068-076>078-087-088-098.
IL...Frost Advisory from 1 AM to 8 AM CDT Saturday for ILZ001-002-
007-009-015.
MO...Frost Advisory from 1 AM to 8 AM CDT Saturday for MOZ009.
&&
$$
SHORT TERM...McClure
LONG TERM...McClure
AVIATION...12
NWS DVN Office Area Forecast Discussion