Frost Advisory 4, NWS Quad Cities, IA

029 
WWUS73 KDVN 260158
NPWDVN

URGENT - WEATHER MESSAGE
National Weather Service Quad Cities IA IL
858 PM CDT Wed Oct 25 2017

...Frost Overnight...

.Expect frost to develop overnight across parts of northwest  
Illinois, especially in low lying areas.

ILZ001-002-007-009-017-018-261000-
/O.CON.KDVN.FR.Y.0004.171026T0500Z-171026T1400Z/
Jo Daviess-Stephenson-Carroll-Whiteside-Bureau-Putnam-
Including the cities of Galena, Freeport, Mount Carroll, 
Sterling, Princeton, and Hennepin
858 PM CDT Wed Oct 25 2017

...FROST ADVISORY REMAINS IN EFFECT FROM MIDNIGHT TONIGHT TO 9 AM
CDT THURSDAY...

* Temperatures...In the mid 30s.

* Timing...From midnight tonight until 9 AM Thursday.

* Impacts...Sensitive outdoor plants may be killed if left 
  uncovered.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Frost Advisory means that frost is likely.  Cover or move
sensitive plants indoors.

&&

$$
RP Kinney

518 
WWUS73 KDVN 260808
NPWDVN

URGENT - WEATHER MESSAGE
National Weather Service Quad Cities IA IL
308 AM CDT Thu Oct 26 2017

...Frost Likely Early This Morning...

.Frost is likely early this morning across parts of northwest 
Illinois, especially in low lying areas.

ILZ001-002-007-009-017-018-261400-
/O.CON.KDVN.FR.Y.0004.000000T0000Z-171026T1400Z/
Jo Daviess-Stephenson-Carroll-Whiteside-Bureau-Putnam-
Including the cities of Galena, Freeport, Mount Carroll, 
Sterling, Princeton, and Hennepin
308 AM CDT Thu Oct 26 2017

...FROST ADVISORY REMAINS IN EFFECT UNTIL 9 AM CDT THIS MORNING...

* Temperatures...In the mid 30s.

* Timing...early this morning.

* Impacts...Sensitive outdoor plants may be killed if left 
  uncovered.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Frost Advisory means that frost is likely. Cover or move sensitive
plants indoors.

&&

$$

183 
WWUS73 KDVN 261406
NPWDVN

URGENT - WEATHER MESSAGE
National Weather Service Quad Cities IA IL
906 AM CDT Thu Oct 26 2017

...Frost advisory expired...


ILZ001-002-007-009-017-018-261515-
/O.EXP.KDVN.FR.Y.0004.000000T0000Z-171026T1400Z/
Jo Daviess-Stephenson-Carroll-Whiteside-Bureau-Putnam-
Including the cities of Galena, Freeport, Mount Carroll, 
Sterling, Princeton, and Hennepin
906 AM CDT Thu Oct 26 2017

...FROST ADVISORY HAS EXPIRED...

Temperatures have warmed into the lower 40s ending the risk of
frost.


$$

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1223 PM CDT Wed Oct 25 2017

...AVIATION UPDATE...

.UPDATE...
Issued at 630 AM CDT Wed Oct 25 2017

Dry air deeper and more prolific than models showing per early
look at 12z DVN raob. Given this plus lack of precip in upstream
obs (cloud ceiling heights mostly at or above 8kft agl), and
quickly passing ascent next couple of hours I have updated to
remove PoPs NW IL backing off just small chance of sprinkles
although with aid of evaporational cooling couldn't rule out a
stray flake as well.

&&

.SYNOPSIS...
Issued at 306 AM CDT Wed Oct 25 2017

Cool morning in progress with temps in the 30s. Winds generally staying
up around 5-10 mph in lingering pressure gradient while increase in
mid/high cloudiness from approaching system working in tandem to limit
any frost formation. Regarding this next system it has the look of a
clipper type system with a weak low over eastern Manitoba diving southeast
along with a strong mid level PV anomaly and accompanying 150+ kt jet
streak. This system will sweep southeast next 12 hrs accompanied by a
chance for light precipitation in some areas, then followed by a
return of clearing skies and building upper ridge resulting in warmer
afternoon temps.

&&

.SHORT TERM...(Today and Tonight)
ISSUED AT 306 AM CDT Wed Oct 25 2017

Will continue to see an increase in cloud cover this morning, as the
weak surface low attendant to mid level wave diving south within
nearly meridional flow passes over the region. East of this low track
(or mainly from southern WI through northern IL) there will be
slightly deeper moisture, and greater top down saturation in
cooler air aided by isentropic ascent which may allow for a chance
of light rain or possibly even a few snowflakes initially. Have
maintained low chance PoPs this AM for generally our NW IL counties,
but given sub-cloud dry air and cloud bases mainly at or above 5kft
agl thinking primarily this is a trace event for sprinkles and maybe
a few snowflakes with onset. Clouds will then quickly decrease
late morning into the afternoon from NW to SE, as the clipper system
shuttles quickly SE and mid/upper level ridging begins to build in.
These factors along with low level WAA will lead to a warmer
afternoon with likely gradient from southwest (warmest, and in the
lower 60s) to northeast (coolest, and in the lower 50s).

Tonight, will be mostly clear with some wisps of mid/upper level
clouds possible attendant to developing elevated WAA wing ahead of
next digging wave from Saskatchewan and Manitoba. Strengthening
pressure gradient overnight will likely lead to slightly warmer
lows west of the Mississippi River (upper 30s to around 40 degrees).
Meanwhile, east of the Mississippi River winds will remain light
with lows in the mid 30s and possibly isolated lower 30s supporting
risk of at least patchy frost especially in river valleys and other
drainage locations. However, enough uncertainty exists with
developing low level WAA and pressure gradient overnight to go with
any frost headlines for our eastern CWA at this time, but will need
to monitor.

.LONG TERM...(Thursday through Tuesday)
ISSUED AT 306 AM CDT Wed Oct 25 2017

Thursday...looks to be the nicest day of the week with dry weather
and temperatures in the mid 50s northeast to upper 60s south
resulting from warm air pushing into the area ahead of the next
storm system.

Thursday night and Friday...Passage of a cold front is expected
sometime Thursday evening which will usher in much colder temps.
Widespread 30s are forecast by Friday morning with recovery only
into the 40s Friday afternoon.  The front should come through dry in
most areas with low pops limited to the northern counties.

Friday night and Saturday...conditions continue to deteriorate as
wrap around clouds and cold advection continues bringing chilly air
into the area.  It looks like the western areas are most exposed to
freeze potential with even a little bit of snow with lows 30s
forecast in that area.  Temps elsewhere in the CWA won't be much
warmer. There could be a very slight and brief accumulation on
grassy surfaces in our westernmost counties.

Saturday night and Sunday...areas escaping the freeze Saturday
morning will likely reach freezing or below Sunday morning as precip
lifts northeast out of the area.  The GFS hints at a more classic
radiational freeze event with less clouds and lighter winds than the
ECMWF and GEM which favors more of an advective typo event.  In
either case, it appears the growing season is coming to an end this
weekend.

Monday and Tuesday...we continue riding the see saw with another
storm system embedded in northwest flow progged to reinforce the
cold air already in place. Model variance is high on the details,
thus pops with various QPF solutions are low at this point.

&&

.AVIATION...(For the 18Z TAFS through 18Z Thursday Afternoon)
ISSUED AT 1221 PM CDT Wed Oct 25 2017

VFR conditions will be seen through 00z/27 as first high pressure
and then a front moves through eastern Iowa and northern Illinois.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&

UPDATE...McClure
SYNOPSIS...McClure
SHORT TERM...McClure
LONG TERM...Wolf
AVIATION...08

Hazardous Weather Outlook
National Weather Service Quad Cities IA IL
320 AM CDT Wed Oct 25 2017

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-
009-015>018-024>026-034-035-MOZ009-010-260830-
Buchanan-Delaware-Dubuque-Benton-Linn-Jones-Jackson-Iowa-Johnson-
Cedar-Clinton-Muscatine-Scott-Keokuk-Washington-Louisa-Jefferson-
Henry IA-Des Moines-Van Buren-Lee-Jo Daviess-Stephenson-Carroll-
Whiteside-Rock Island-Henry IL-Bureau-Putnam-Mercer-Henderson-
Warren-Hancock-McDonough-Scotland-Clark-
320 AM CDT Wed Oct 25 2017

This Hazardous Weather Outlook is for portions of north central
Illinois...northwest Illinois...west central Illinois...east
central Iowa...northeast Iowa...southeast Iowa and northeast
Missouri.

.DAY ONE...TODAY AND TONIGHT

With a chilly air mass in place and light winds tonight, patchy
frost is possible in low-lying areas of northwest Illinois.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

A cold front moving through the area late Thursday will likely
presage the end of the growing season. Sub-freezing temperatures
are possible Saturday morning and likely Sunday morning. Some
areas may experience the first snow flakes of the season early
Saturday morning, but no impacts are expected to result.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be required.