National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS63 KDVN 180549
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1249 AM CDT Thu Apr 18 2024

.KEY MESSAGES...

- There is a marginal or level 1 out of 5 risk for severe
  thunderstorms in far southeast Iowa, northeast Missouri and
  west central Illinois on Thursday. The main threat would be
  hail up to the size of quarter.

- Frost/freezing temperatures possible later this week into the
  weekend.

- Chance for rain early next week and milder.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 201 PM CDT Wed Apr 17 2024

A closed upper level low and its surface low continue to lift
northeastward into the Upper Great Lakes with high pressure
building into Nebraska and Kansas. Winds remained gusty at 2 PM
and were generally westerly at 20 to 25 MPH with gusts up to 40
mph. Temperatures ranged from 52 degrees at Dubuque to 63
degrees at Keokuk.

High pressure is forecast to quickly move across the area
tonight. This will allow winds to quickly drop off overnight
with winds becoming light and variable. Low temperatures on
Thursday morning will range from the mid 40s north of Interstate
80 to the lower 50s in far northeast Missouri.

As high pressure exits to the east, another shortwave moving
through the flow overspreads the area from 9 to 18 UTC from east
central into west central Illinois. CAPE will build northward
into southeast Iowa, far northeast Iowa and west central
Illinois and far northeast Missouri to a few hundred J/KG with 0
to 6 km shear around 50 knots. Think that a line of storms will
develop during the early morning hours and dive southeastward
along the CAPE gradient into northern Missouri and central
Illinois. This seems most likely if storms develop near the warm
front in far northern Missouri or precipitation will be forced
by an frontogenetical band associated with another cold front
that will move across the area Thursday morning. Models also
show scattered showers developing behind this initial line of
storms and continue through the remainder of the day. High
temperatures on Thursday will be cooler and range be in the mid
50s. It remains to be seen which solution will win out.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Issued at 201 PM CDT Wed Apr 17 2024

Thursday night through this weekend: Deepening trough in the Great
Lakes region will send rather chilly temperatures into our forecast
area, due to a northwest flow aloft. H8 temps drop to -4 to -6C
allowing for several days of below normal temperatures. With the
recent green-up and sensitive flowers the potential for a frost or
freeze will need to be monitored for headlines. The NBM continues to
show a 50-80 percent probability of freezing temperatures,
especially in our northern counties. However, our entire area is
vegetation susceptible. Lows Thursday night, Friday night, and
Saturday night look to be in the upper 20s to lower 30s north to the
mid to upper 30s south. Highs will be in the 50s.

Early next week: Milder with a zonal flow with another disturbance
in the flow bringing a round of showers on Monday into Monday night.
Highs will be in the 60s.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1249 AM CDT Thu Apr 18 2024

VFR under clear skies will be with us for at least a few hours as
a surface high pressure ridge axis remains overhead. However,
these quiet conditions will be short-lived as a system moves in
from the west later on this morning and bring increasing chances
of showers and storms, lingering through the afternoon hours
today. Timing and intensity of the precipitation is a bit
uncertain, given differences among the high-resolution models.
However, it appears that there will be slightly better support
for thunderstorms in the afternoon, especially for MLI and BRL,
so used PROB30 groups to highlight when the most likely
timeframe and impact for these storms will be. Overall,
confidence is high for widespread MVFR/IFR conditions with this
system. This activity moves out by tonight, leading to VFR.

&&

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

&&

$$

SHORT TERM...Cousins
LONG TERM...Haase
AVIATION...Schultz