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fxus63 kdvn 142223 
afddvn

Area forecast discussion
National Weather Service Quad Cities Iowa Illinois
523 PM CDT Mon Oct 14 2019

..00z aviation update...

Synopsis...
issued at 226 PM CDT Mon Oct 14 2019

After a cold start with frost, sunny skies prevailed across the
area. Below normal temperatures were seen, as weak ridging aloft
moved east over the upper Great Plains and surface high pressure
drifted east over the Ohio River valley.

At 2 PM, temperatures were in the 50s, with dewpints in the 30s.
Strong shortwave to impact the area overnight tonight, was seen
on WV imagery moving over Montana.

&&

Short term...(this evening through tuesday)
issued at 226 PM CDT Mon Oct 14 2019

Main forecast concern is on precipitation chances after midnight
tonight and frontal passage Tuesday, along with cloud trends
impacting temperatures.

Tonight...other than some mid and high level clouds streaming
over northern Iowa, much of the area will see mostly clear skies
this evening. An area of low pressure will track east over South
Dakota and into Minnesota, with an associated warm front lifting
northeast over Iowa. Strong warm air advection on the nose of the low level jet
will allow increasing clouds and precipitation to develop after
midnight. Some isolated thunderstorms will be possible as well as
18z rap 700-500 mb Theta-E lapse rates go negative overnight.
Latest href members and hrrr suggest precipitation will not start
until after 07z this evening, due to dry mid level air and I am
not expecting much in the way of quantitative precipitation forecast tonight, with rain amounts
less than a tenth of an inch. Some models even suggest some of our
area may be completely dry, with just our far north and far south
seeing precipitation. South winds and increasing clouds will keep
temperatures much warmer than previous mornings, with lows only
dropping into the lower 40s north, to lower 50s south.

Tuesday...cold frontal passage to push through the area late
Tuesday morning, with steady or slowly falling temperatures during
the afternoon. Strong cold air advection with gusty northwest winds will be seen
behind the front along with clouds. High temperatures may be a
challenge due to cloud cover. I am currently going with upper 50s
for highs northwest of a Iowa City to Freeport line to the lower
60s south, but if clouds remain overhead for a longer period of
time or go further south, these readings may be too high.

Long term...(tuesday night through monday)
issued at 226 PM CDT Mon Oct 14 2019

Quiet and dry conditions will start the extended forecast with
rising temperatures. Increasing rain chances will be seen late
Friday and into early next week.

Dry northwest flow and high pressure is expected Tuesday night
through much of Friday, with temperatures going above normal by
the end of the work week. Wednesday will be a rather brisk and
cold day, as high pressure builds into the region and 850 temps
remain below 0c across the entire County Warning Area. Clouds and cold air advection will once
again keep highs from rising much and will only reach the upper
40s and lower 50s.

Friday night-Monday...the weather becomes more active with a
southwest flow pattern setting up. Several waves will move
through the flow, with the strongest expected to impact the area
late Sunday and into Monday. Deep moisture will return with an
open Gulf and there will be the possibility of significant
rainfall as we head into next week.

&&

Aviation...(for the 00z tafs through 00z Tuesday evening)
issued at 510 PM CDT Mon Oct 14 2019

A fast moving cold front will bring a chance of showers and lower
ceilings to mainly the river sites late tonight until mid morning
Tuesday. This will be followed by brisk west/northwest winds, and some
lower ceilings evolving during the afternoon continuing beyond the
end of the taf cycle as area becomes entrenched in cold, cyclonic
flow.

Precipitation...
chance of showers roughly in the 08z-14z timeframe. Have handled
with prob30 mention. Isolated storm is possible, but probability
appears too low at this time for any mention.

Visibility...
predominantly VFR, with a low probability of very brief MVFR/IFR
in the strongest showers or isolated storms.

Ceilings...
unlimited for most of tonight. Late tonight through Tuesday am,
expecting VFR with a period of MVFR at the river sites.
Tuesday PM developing widespread MVFR at the northern sites (dbq,
cid) evolving further south at mli and brl late in the period and
just beyond.

Winds...
tonight, easterly turning southerly and increasing above 10 kts.
Strengthening low level jet will Foster low level wind shear after 06z until 12z
with winds increasing to around 35-40 kts from S/SW at 2kft agl.
Cold front passes by mid to late am with winds shifting from the
west/northwest becoming gusty 20-30+ kts during the PM.

&&

Hydrology...
issued at 1007 am CDT Mon Oct 14 2019

No significant changes were made to river forecasts this morning.
River levels on tributaries that are above flood stage continue to
fall. Along the Mississippi, a crest currently in Dubuque will
continue working downstream, and will reach the Quad Cities by late
Tuesday. This will continue working downstream, but is expected not
to produce significant rises in levels.

Looking ahead, there is a chance of rain showers across the entire
hydrologic service area tonight. However, forecast quantitative precipitation forecast amounts
below 0.10" will have no impact on Current River levels.

Active weather may return to the region this weekend and early next
week as the upper level flow becomes more active and moisture is
brought back north from the Gulf of Mexico. The climate prediction
center is forecasting a high probability (60-70%) of above normal
precipitation for the entire mid-Mississippi River valley from Oct
19-23. While it is too early to pinpoint exact rainfall amounts for
this period, the potential does exist for renewed rises or prolonged
falls along area rivers by mid to late next week. Please stay tuned
to the latest forecasts and information.

&&

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

$$

Synopsis...gross

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