Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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000
FXUS63 KDVN 290521
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1221 AM CDT Fri Mar 29 2024

.KEY MESSAGES...

- Low chance of a brief rain shower or sprinkles today and
  tonight.

- High confidence for showers and storms Friday night, and
  again early next week; hail is possible with the strongest
  cells Friday night.

- Periods of rain likely Sunday and Sunday night.

- Wide range in temperatures early next week with more beneficial
  rain expected.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 245 PM CDT Thu Mar 28 2024

SPC mesoanalysis had a mid-level ridge situated over the Plains,
with WNW 700mb winds downstream leading to broad warm air
advection across portions of the Upper Mississippi Valley. This
forcing has led to development of "elevated" echoes on the
radar, much of which is virga due to a very dry sub-cloud layer
between the surface and 8 to 10 kft AGL. However, have seen a
few mPING reports of sprinkles or light rain this afternoon
across the southern outlook area along/south of Highway 34.
Expect the low to mid-level WAA regime to continue into tonight,
so added sprinkles to the forecast and have a slight chance for
showers in the far east-central outlook area.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 245 PM CDT Thu Mar 28 2024

Friday: A mid to upper-level ridge is forecast to shift over
the area as the surface pressure gradient increases. This will
result in much warmer temperatures into the mid/upper 60s for
most locations and breezy SE winds of 15 to 25 mph. The
exception will be across the far north where forecast temps are
near 60 F. Overall, a nice day is expected with dry conditions
through the afternoon.

Friday night: A disturbance in the zonal flow will bring a round of
showers and scattered thunderstorms. Low pressure developing in the
central Plains will push a warm front to northern MO/central IL.
A 40-50 kt low level jet (LLJ) impinging on this front will be
providing strong forcing/warm air advection over this front. Strong
deep layer shear, elevated buoyancy (MUCAPE 500-900 J/kg), and
freezing level 9k ft suggests a risk for hail, mainly nickel to dime
size. However, can`t rule out 1+ inch hail in any stronger storms.
SPC has "general thunder" in our forecast area but if later models
show better CAPE and/or surface based storms then an upgrade to the
risk may be needed. NAMNEST indicates scattered thunderstorms
developing in the evening around 7-9 pm, then gradually diminishing
after midnight as the disturbance pushes off to our east.

Easter weekend: Continued rather mild with highs mainly in the mid
50s to mid 60s. However, chances for rain continues for Sunday.

Early next week: Confidence is high as both global models indicating
another large/slow moving storm system. This looks to be another
widespread soaking rain and a few thunderstorms. The ECMWF has kept
the surface low tracking across northern MO keeping the threat of
severe weather south of our forecast area. However, the GFS has
shifted the track of the low and strong warm front into our southern
counties increasing the severe threat. Meanwhile, with copious
western Gulf of Mexico moisture streaming northward, widespread rain
amounts of 1-2 inches appears likely across much of the forecast
area. This agrees with WPC QPF graphics. The NBM has a nice
temperature gradient across our area, with highs only around 50
along Highway 20 to the mid 60s south. Then in the lower to mid 50s
Tuesday and Wednesday.

April 3-4: Global models diving a deep closed low southward into the
Midwest/Great Lakes as phasing occurs with the northern and southern
streams. If this is correct then the NBM temperatures are way too
warm with negative h8 temps. This scenario would also suggest the
potential for snow showers assuming this phasing occurs.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1218 AM CDT Fri Mar 29 2024

VFR weather will continue through early evening hours Friday,
with winds generally remaining light east/northeast tonight,
then southeast through the day Friday. Friday night, south winds
return, with some potential for gusts over 20 kts by the end of
the period. This transition will be due to a warm front
developing over the area, and with that an increase in mid
clouds today will be followed by a round of high based showers
and thunderstorms Friday evening, developing first between
00-03z in Iowa, then spreading quickly through Illinois by 06z,
and decreasing after midnight. Some brief heavy downpours and
hail are possible within these storms.

&&

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

&&

$$

SHORT TERM...Uttech
LONG TERM...Haase
AVIATION...Ervin


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