Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus63 kdvn 150851 
afddvn

Area forecast discussion
National Weather Service Quad Cities Iowa Illinois
251 am CST Fri Nov 15 2019

Synopsis...
issued at 251 am CST Fri Nov 15 2019

The night has shaped up to be nice and quiet one outside of the
Bureau with chilly temperatures and some areas of frost. As of 2 am,
temperatures ranged from 14 in Clinton (due to the snowpack), to 21
in Fort Madison underneath clear skies and light & variable winds.
Surface analysis showed high pressure centered roughly over
Oklahoma, with ridging extending into the Ohio River valley. This
ridge will be the primary driver of our weather for the short term
period.

&&

Short term...(today and tonight)
issued at 251 am CST Fri Nov 15 2019

Key messages:

1) primarily dry conditions expected

2) patchy fog late tonight / Saturday morning

Little in the way of impactful weather is expected today as the
surface high pressure continues moving over the area. As it does so,
850 temperatures will (finally) climb above freezing, helping US get
a little warmer then previous days (especially with plentiful
sunshine). Currently advertise afternoon highs ranging from the
upper 30s north of Highway 30, to upper 40s over southeast Iowa and
northeast Missouri. This should assist in helping to melt some of
the leftover snowpack.

Mostly quiet weather continues overnight with clouds increasing as
low-level warm air advection and moisture increases across the region. The
increasing clouds will help keep our temperatures warmer than last
night, with values likely to be a little cooler over the remaining
snowpack. Overnight lows expected to be in the low to mid 20s.

There is some potential for fog development late tonight and
Saturday morning per latest sref and some high-res cams, likely as
increasing moisture builds over the wet ground and remaining snow
pack. This will mainly be a concern where clouds will not be in full
coverage, which (as of this forecast package) will be over southeast
Iowa, west central Illinois and northeast Missouri. For now, have
introduced patchy fog across this area as confidence on widespread
fog remains low due to uncertainties with the cloud coverage. This
fog will remain a concern briefly as we head into the long term
period.

Long term...(saturday through thursday)
issued at 251 am CST Fri Nov 15 2019

Slightly warmer weather that moves in this weekend will be the main
story through much of next week. There will be periodic chances for
at least light precipitation and the initial system arriving Sunday
will be the main focus.

An upper level shortwave passes through the area Sunday, digs
into a longwave trough over the central U.S. Sunday night. 00z
forecast models are in fair agreement with the timing of this
feature and an associated cold front that will push through late
in the day. Thermal profiles will initially support snow with the
developing band of precipitation in the predawn hours over eastern
Iowa, changing to rain as progresses eastward into Illinois by early
afternoon. The quick movement and quantitative precipitation forecast likely well below .10 inches
in most areas will limit any snow to less than a quarter inch,
which should melt as temperatures reach highs in the upper 30s
north to upper 40s south. For now, pops are kept in the chance
range, but this will likely be increased in later forecasts, based
on the good run to run consistency.

A northwest flow follows for the early to mid part of next week
with a weaker system, that has much poorer model agreement,
passing through the area Monday night. A much stronger system is
still shaping up around Wed night into Thursday, during a
transition to a more active zonal upper level flow. This system
may have Gulf moisture available for potentially significant
rainfall, but there remains considerable uncertainty at this
timeframe in the forecast track and thermal features. For now, the
forecast mentions both rain ad snow, or a mix, which could easily
be all rain with the colder air not arriving until well after the
precipitation ends Thursday night into Friday. Expected highs in
the 40s and lows in the 20s and 30s next week would still be
slightly below normal for mid to late November.

&&

Aviation...(for the 06z tafs through 06z Friday night)
issued at 1036 PM CST Thu Nov 14 2019

Clear, quiet, and VFR weather will continue under high pressure
through Friday night.

&&

Dvn watches/warnings/advisories...
Iowa...none.
Illinois...none.
MO...none.
&&

$$

National Weather Service Glossary of Abbreviations