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000
FXUS63 KDVN 120212
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
912 PM CDT Thu Apr 11 2024

.KEY MESSAGES...

- Scattered afternoon showers and a few thunderstorms this afternoon,
  with the stronger storms possibly capable of sub-severe hail
  and wind gusts. are over northwest Illinois. One to a quarter
  inch of rain is possible.

- It will be breezy today through Friday with northwest winds of  10
  to 20 MPH and gusts up to 35 MPH.

- A warming trend will begin this weekend and continue into
  early next week with temperatures well above normal
  especially Sunday through Tuesday.

- We continue to watch another storm system forecast to move
  into the area early next week and bring chances of rain
  showers and thunderstorms to the area, some may be strong
  Monday night and Tuesday.

&&

.UPDATE...
Issued at 909 PM CDT Thu Apr 11 2024

On the last two updates, I`ve removed thunder from the evening
forecast, while still keeping "showers" as the weather type.
The areas of light rain and moderate showers will continue to
slowly rotate south over the north 1/2, and southeast over the
south half through the early morning hours Friday. Coverage
appears to be increasing for the next couple hours, as the main
vorticity center drifts over the area.

ERVIN

&&

.SHORT TERM /THROUGH SATURDAY/...
Issued at 246 PM CDT Thu Apr 11 2024

Tonight...Short wave trof aloft now seen on water vapor imagery
acrs the MN/IA border, will look to sweep down to the eastern OH RVR
Valley by Friday morning. Some decent lift combined with plume of
6.5 to 7 C/km mid level lapse rates will continue to induce isolated
to sctrd showers and some thunderstorms acrs the area into the
evening. Storm layer shear and thermodynamics support the stronger
cells possibly producing hail up to dime size(mainly pea though),
and wind gusts mixing out to 45 MPH or so. Localized strips of 0.10
to 0.25 of an inch of rainfall under the precip paths, with zones of
repeated activity or slowed motion getting a half inch. An item of
interest may be the potential of funnels out of cells that slow and
anchor along convergent and now quasi-stationary north-south
boundary draped acrs northwest IL. Some differential heating in this
vicinity also helping the cause. The precip should diurnally
decrease and slip southeast tonight with passage of upper trof axis.

Lingering tight cyclonic sfc pressure gradient will continue to
drive northwesterly wind gusts up to 30 KTs well into the evening,
with a mid to late Friday mix-out morning re-surge. Overnight cool
advection to advect temps down into the low to mid 40s.

Friday...Some sunshine with breezy conditions continuing, gusts to
35 MPH until mid to late afternoon when the pressure gradient will
look to relax into the Friday evening period. But cooled airmass
influx indicated by lowered thicknesses and H85 MB temps of 0 to 3C
will make for somewhat a cooler day even with deep mixing with highs
in the upper 50s to low/mid 60s. Some ambient cellular CU likely
especially east of the river.   ..12..

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Issued at 246 PM CDT Thu Apr 11 2024

Saturday through Monday: Very warm with highs well into the 70s with
some areas in the lower to mid 80s! This big warm-up due to a zonal
flow ahead of a major upper level trough pushing into the Rockies by
Monday. Ridging ahead of this trough moves into the DVN forecast
area on Monday so this looks to be the warmest day.

Monday night and Tuesday: Severe thunderstorms are possible with SPC
indicating a 15% probability (rare SLGT risk day 6) over much of the
forecast area. A significant severe weather outbreak (all-modes)
appears to be setting up with a very potent upper low tracking out
of the southern Rockies and to se Minnesota by Tuesday evening. The
surface low of 983 mb is very deep and spells trouble in April. Even
this far out the global models suggest very strong shear, impressive
diffluence aloft, left front quadrant of a powerful jet stream (125
kts), a very strong wind field (h5 90kts/h8 60kts) and plenty of
Gulf warmth/moisture (thermodynamics). However, big details to be
worked out yet are the placement of the warm front and timing the
cold front, factors that will help to determine the outcome of this
event. Stay tuned over the next several days for further updates.

Mid/late week: Cooler temperatures and a chance for rain but
confidence is low this far out with regard to any storm systems that
may or may not affect our area.

Haase

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 615 PM CDT Thu Apr 11 2024

Widely scattered showers will continue to move southeast over
eastern Iowa and northwest Illinois through mid evening, but
coverage will continue to decrease, with any thunderstorms
extremely isolated. Windy northwest winds will continue through
the period, as sustained winds of 15 to 20 kts, gust to near 30
kts through the entire period. Skies should be clear or VFR
through the period, with good visibility outside of the small
showers this evening.

&&

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

&&

$$

UPDATE...Ervin
SHORT TERM...12
LONG TERM...Haase
AVIATION...Ervin