Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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FXUS63 KDVN 230818

Area Forecast Discussion
National Weather Service Quad Cities IA IL
318 AM CDT Sun Apr 23 2017

Issued at 317 AM CDT Sun Apr 23 2017

High pressure was centered over the Great Plains this morning.
This led to clear skies and near calm winds tonight. Temperatures
ranged from the upper 30s to the mid 40s early this morning. This
high pressure isn`t forecast to move much through the short term
and is the primary weather producer during this period.


.SHORT TERM...(Today and Tonight)
ISSUED AT 317 AM CDT Sun Apr 23 2017

The beautiful Sunday that has been forecast for the past few days
is now here. Main forecast concern in the short term period are
the high and low temperatures. H5 ridging and convergence will
lead to subsidence across the area. The flow is forecast to turn
zonal later during the day and may advect in some very high
cirrus. Otherwise, light winds with highs in the upper 60s to lows
70s are still expected. Most of the deterministic models seem to
be too low with their highs today so trended towards MOS and RAP
model guidance.

.LONG TERM...(Monday through Saturday)
ISSUED AT 317 AM CDT Sun Apr 23 2017

A unsettled period of showers and embedded storms becoming more
likely mid to late this week with significant rainfall amounts.

Long Term Forecast Confidence Assessment...Fair to poor or average
to below average.  Reason is trends are now showing a common spring
phenomena of system slowing down as jet starts to decelerate. This
results in slower and larger storms systems along front. Run to run
of all solutions suggest this isn`t done so timing, coverage and
amounts of precipitation with each day are still poor where
boundaries and lows track still uncertain.  What is apparent is
marginal or no severe weather risk remains the case with most
locations picking up rain amounts of .5 to 1.5+ inches by next
Sunday. Area highs and lows days 3-7 due to cloud coverage and
precipitation may easily be off by 5+ degrees with timing, coverage
and uncertainty of above issues.

Monday...Once again only minor changes.  last fair and mild day with
slightly above normal temperatures of 70 to 75 degrees.  Southerly
of 10 to 20+ mph. Lows mostly lower 50s for Tuesday AM.

Tuesday & Tuesday night...A slower frontal system to approach late
with best forcing behind boundary for dry or mostly dry day. Delayed
passage of front and sunshine should support highs lower to middle
70s and possibly some upper 70s SE sections.  Have 20 to 30 POPS of
showers with isolated storms northwest with limited instability and
moisture resulting in CAPE values AOB 500 J/KG or just a few brief
non-severe storms. Tuesday night...increased POPS as front nearly
stalls and low appears likely to develop in Missouri for enhanced
forcing.  Trends suggest higher POPS with moderate rain amounts with
only embedded storms of non-severe nature attm. Mins mostly
lower/mid 50s with upper 40s far NW sections.

Wednesday & Wednesday night...lots of clouds and rain suggested as
surface low tracks across the region with just embedded storms with
limited instability of CAPE AOB 750 J/KG.  Moderate rain totals
mostly suggested attm. Highs mid 50s northwest to mid 60s SE
sections. Wednesday night...blustery northwest winds to bring in
colder air with concern clouds/mixing supports lows about 3 degrees
higher of current mostly upper 30s to lower 40s for later shifts to
reassess. Strength and track of low may change as well as impacting
area lows and when rains end.

Thursday and Thursday night...mostly fair to partly cloudy with
colder air and have lowered highs into the mid to upper 50s and dry
with light to moderate northwest wind.  Thursday night...clouds to
increase late ahead of next system which may impact lows with
current forecast of upper 30s north to mid 40s south.  If trend for
next system to be slower, then clouds will be delayed and lows could
be easily 3 to 5 degrees too high for later shifts to review.

Friday and Saturday...low confidence forecast.  Reason is track and
timing on next decent storm system.  Best estimates are decent rains
expected with locally 1+ inch amounts possible of rain showers and
some embedded thunder and brisk easterly winds over at least north
1/2 of the region.  Highs in the 50s and 60s with low track key to
how much of the area is in the 50s or 60s.  Friday night...lows in
the 40s to near 50F south.  Saturday night lows is based on clearing
as storm system moves NE with mostly lower to middle 40s which if
low is stronger and clearing occurs are 3 to 5 degrees too high.

Sunday...Highs pressure to move in with cool below normal temps with
highs in the 50s and lows Sunday night in the 40s with some 30s


.AVIATION...(For the 06Z TAFS through 06Z Sunday Night)
ISSUED AT 1137 PM CDT Sat Apr 22 2017

VFR conditions will remain in place overnight through Sunday as
high pressure moves over the region. Under clear skies, winds will
be light and variable overnight, becoming light south to southwest
by late Sunday afternoon.




LONG TERM...Nichols
AVIATION...Sheets is the U.S. government's official web portal to all federal, state and local government web resources and services.