Area Forecast Discussion
Issued by NWS Chicago, IL

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FXUS63 KLOT 170851

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
251 AM CST Fri Feb 17 2017

248 AM CST

Through tonight...

Didn`t make many changes to the going forecast as near to possibly
record breaking warmth is expected today. High temps will soar
into the low 60s after a warm front surges north this morning.
Southwest winds will gust to around 20 MPH. Low temps will be
around 40 tonight.



248 AM CST

Saturday through Thursday...

Above normal temps continue into early next week. However, a lake
breeze is expected Saturday and Sunday, and temperatures along the
lake will fall into the 50s if not upper 40s Sunday thanks to cool
lake temperatures.

A low pressure system forms over the northern plains Sunday night
and lifts to Hudson Bay Tuesday night. The low`s cold front is
progged to bring rain to the region Monday night into Tuesday
morning.  Winds remain southwest, and there isn`t a significant cold
push behind the front. Highs on Tuesday will be in the upper 50s to
low 60s.

Zonal flow sets up aloft keeping systems to our north and south
through the middle of the week.  Blend of models kept a chance of
rain in the forecast for Tuesday night, but currently only one model
is featuring precip at that time. Lowered precip chances across much
of the area and have low confidence in precip occurring.

The next strong low forms over the plains Thursday and travels over
the forecast area late next week.  Will keep an eye on this system
due to it`s dynamic nature. While it`s much too early to discuss
specifics, models suggest thunderstorms may be on the horizon.

Outside of lake breezes, high temperatures remain in the 50s to 60s
throughout the forecast period. Low temps vary from the mid to upper
30s Saturday night to near 50 Monday night.




427 AM CST

We will be heading into an unseasonably warm stretch of weather with
near to possibly record breaking warmth at times. Here are some
statistics on daily records, and consecutive days of 50+, 60+ degrees.


Chicago:                         Rockford:
      High:      High Min:       High:      High Min:
2/17: 60 (1880)  42 (1890)       59 (1981)  39 (1961)
2/18: 62 (1981)  45 (1981)       58 (1981)  38 (1997)
2/19: 65 (1930)  51 (1994)       63 (1930)  42 (1994)
2/20: 64 (1930)  49 (1930)       61 (1983)  46 (1930)
2/21: 67 (1930)  47 (1930)       64 (1930)  42 (1930)


Chicago:                         Rockford:
Longest in February              Longest in February
8 days: 2/22-29/2000             8 days: 2/22-29/2000
        2/18-25/1930                     2/18-25/1930
7 days: 2/22-28/1998             5 days: 2/23-28/1998
6 days: 2/24-29/1976                     2/16-20/1981
        2/11-16/1882                     2/25-29/1932
5 days: 2/19-23/1943             4 days: 2/12-15/1984
        2/25-29/1932                     2/24-27/1976
        2/9-13/1876                      2/21-24/1927

Longest in Meteorological Winter
12 days: 12/14-25/1877           8 days: 2/22-29/2000


Chicago:                         Rockford:
Longest in February              Longest in February
4 days: 2/24-27/1976             3 days: 2/19-21/1930
3 days: 2/19-21/1930                     2/23-25/1930
                                 2 days: 2/25-26/2000

Longest in Meteorological Winter
5 days: 12/2-6/1998              3 days: 2/19-21/1930



For the 06Z TAFs...

Main forecast concern remains winds through the period. East/
southeast winds are expected to remain under 10kts and may become
light and variable overnight. A warm front will lift north across
the area Friday morning into Friday afternoon. Winds will likely
become light southerly in the morning and then begin to increase
during the late morning/early afternoon. Still some uncertainty
regarding how strong winds become but as the gradient tightens and
the low levels mix...gusts as high as 20kts are possible. These
gusts should diminish with sunset Friday evening but a period of
10-12kts could continue Friday evening.

Some patchy/shallow fog is possible overnight into Friday morning
mainly in the usual more rural locations. Confidence is low
regarding how much fog may develop. Mid/high clouds will begin to
scatter overnight into Friday morning with skc expected by Friday
evening. cms


148 AM CST

Southeasterly winds of 10 to 20 KT over the lake early this
morning will gradually veer southerly during the day today as a
warm front shifts northward over the lake. A period of
southwesterly winds are then expected to set up over the lake
tonight before a weak cold front shifts over the lake early
Saturday setting up light westerly flow. Wind speeds look to
abate Saturday afternoon over southern Lake Michigan as a surface
high approaches the western lakes, and this could allow the
afternoon winds on southern Lake Michigan to turn onshore as a
lake breeze tries to develop.

The main period of potential higher impact winds and waves during
the period looks to be Monday and Monday night. During this
period, some strong southerly winds, potentially up to 30-35 KT
will be possible as a storm system shifts northward into south
central Canada. Following this, it appears the weather pattern
could get more active later next week, and this could result in
another potent storm system impacting the Great Lakes region late
in the period.






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