Alton, Illinois Weather Conditions

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Current Conditions

  • 72°
  • Mostly Cloudy
  • Wind: East 7 mph
  • Humidity: 83%
  • Visibility: 10.0 miles
  • Dew Point: 66°
  • Pressure: 30.06 in. -

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Next 12 Hours

7  pm
10  pm
1  am
4  am
7  am
Thunderstorm
T-storms
Thunderstorm
T-storms
Partly Cloudy
Partly Cloudy
Partly Cloudy
Partly Cloudy
Chance of a Thunderstorm
Chance of T-storms
82°
75°
77°
75°
70°
Forecast data from the National Digital Forecast Database.

5 Day Forecast

  • Thursday
  • Chance of a Thunderstorm
  • High: 88 °
  • Low: 70 °
  • Chance of T-Storms
  • Friday
  • Chance of a Thunderstorm
  • High: 86 °
  • Low: 68 °
  • Chance of a Thunderstorm
  • Saturday
  • Thunderstorm
  • High: 84 °
  • Low: 68 °
  • T-Storms
  • Sunday
  • Chance of a Thunderstorm
  • High: 84 °
  • Low: 70 °
  • Chance of T-Storms
  • Monday
  • Chance of a Thunderstorm
  • High: 86 °
  • Low: 70 °
  • Chance of T-Storms

Forecast for Alton, Illinois

Updated: 10:00 PM CDT on August 27, 2014

Excessive heat warning in effect until 8 PM CDT this evening...
  • Wednesday

    Partly cloudy with a chance of a thunderstorm and a chance of rain in the morning, then overcast with thunderstorms and rain showers. High of 91F. Winds from the WSW at 5 to 10 mph shifting to the North in the afternoon. Chance of rain 30%.

  • Wednesday Night

    Partly cloudy with thunderstorms and rain showers. Fog overnight. Low of 70F. Winds from the NE at 5 to 10 mph. Chance of rain 40%.

  • Thursday

    Mostly cloudy with a chance of a thunderstorm and a chance of rain. High of 88F. Winds less than 5 mph. Chance of rain 40%.

  • Thursday Night

    Overcast with a chance of a thunderstorm and a chance of rain in the evening, then partly cloudy with a chance of a thunderstorm and a chance of rain. Low of 70F. Winds less than 5 mph. Chance of rain 20%.

  • Friday

    Partly cloudy with a chance of a thunderstorm and a chance of rain in the afternoon. Fog early. High of 86F. Winds from the South at 5 to 10 mph. Chance of rain 20%.

  • Friday Night

    Overcast with a chance of a thunderstorm and a chance of rain. Low of 68F. Winds from the South at 5 to 10 mph. Chance of rain 40% with rainfall amounts near 0.2 in. possible.

  • Saturday

    Mostly cloudy with thunderstorms and rain showers. High of 84F with a heat index of 90F. Winds from the SW at 5 to 10 mph. Chance of rain 60%.

  • Saturday Night

    Overcast with a chance of a thunderstorm and a chance of rain in the evening, then partly cloudy. Fog overnight. Low of 68F. Winds from the SSW at 5 to 10 mph.

  • Sunday

    Partly cloudy with a chance of a thunderstorm and rain. High of 84F. Winds from the SSW at 5 to 10 mph. Chance of rain 50%.

  • Sunday Night

    Partly cloudy with a chance of a thunderstorm and rain. Fog overnight. Low of 70F. Winds from the South at 5 to 10 mph. Chance of rain 20%.

  • Monday

    Overcast with a chance of a thunderstorm and rain. High of 86F. Winds from the SW at 10 to 15 mph. Chance of rain 40%.

  • Monday Night

    Overcast with a chance of a thunderstorm. Fog overnight. Low of 70F. Winds from the SSW at 5 to 10 mph shifting to the NNW after midnight. Chance of rain 70% with rainfall amounts near 0.8 in. possible.

  • Tuesday

    Partly cloudy. High of 90F. Winds from the NNE at 5 to 10 mph.

  • Tuesday Night

    Partly cloudy. Low of 64F. Winds from the ESE at 5 to 10 mph.

  • Wednesday

    Overcast with a chance of a thunderstorm. High of 90F. Winds from the South at 5 to 10 mph. Chance of rain 70% with rainfall amounts near 0.2 in. possible.

  • Wednesday Night

    Partly cloudy with a chance of a thunderstorm. Fog overnight. Low of 63F. Winds less than 5 mph. Chance of rain 70% with rainfall amounts near 0.4 in. possible.

  • Thursday

    Mostly cloudy with a chance of a thunderstorm. Fog early. High of 81F. Winds less than 5 mph. Chance of rain 30%.

  • Thursday Night

    Mostly cloudy with a chance of a thunderstorm. Fog overnight. Low of 63F. Winds less than 5 mph. Chance of rain 40%.

  • Friday

    Partly cloudy with a chance of a thunderstorm. Fog early. High of 84F. Winds less than 5 mph. Chance of rain 50%.

  • Friday Night

    Partly cloudy with a chance of a thunderstorm. Fog overnight. Low of 63F. Winds less than 5 mph. Chance of rain 40%.

  • Saturday

    Clear with a chance of a thunderstorm. Fog early. High of 81F. Winds less than 5 mph. Chance of rain 40%.

  • Saturday Night

    Clear. Fog overnight. Low of 63F. Winds less than 5 mph.

  • Sunday

    Clear. High of 79F. Winds less than 5 mph.

  • Sunday Night

    Clear. Fog overnight. Low of 63F. Winds less than 5 mph.

Severe Weather Alert Descriptions

 Local Storm Report 



08/27/2014 0510 PM

Collinsville, Madison County.

Thunderstorm wind damage, reported by Emergency Mngr.


            Large tree blown down onto a power line




Personal Weather Stations

Personal Weather Stations [Add your weather station!]

Location: Alton - Beacon, Alton, IL

Updated: 8:16 PM CDT

Temperature: 76.0 °F Dew Point: 71 °F Humidity: 85% Wind: Calm Pressure: 30.02 in Hourly Precipitation: 0.00 in Heat Index: 77 °F Graphs

Location: Alton - Christian Hill Area, Alton, IL

Updated: 8:15 PM CDT

Temperature: 74.4 °F Dew Point: 69 °F Humidity: 83% Wind: Calm Pressure: 30.01 in Hourly Precipitation: 0.00 in Heat Index: 74 °F Graphs

Location: MesoWest US-67 @ Clark Bridge IL US ILDOT, Alton, IL

Updated: 7:25 PM CDT

Temperature: 74 °F Dew Point: 72 °F Humidity: 95% Wind: NNW at 1 mph Pressure: - Hourly Precipitation: 0.00 in Heat Index: 71 °F Graphs

Location: Milton Area - Oscar, Alton, IL

Updated: 8:05 PM CDT

Temperature: 73.1 °F Dew Point: 72 °F Humidity: 95% Wind: Calm Pressure: 30.01 in Hourly Precipitation: 0.00 in Heat Index: - Graphs

Location: Brecht Ln, Godfrey, IL

Updated: 8:12 PM CDT

Temperature: 74.5 °F Dew Point: 68 °F Humidity: 81% Wind: ESE at 2.7 mph Pressure: 29.92 in Hourly Precipitation: - Heat Index: 75 °F Graphs

Location: WEST ALTON, West Alton, MO

Updated: 7:50 PM CDT

Temperature: 75.2 °F Dew Point: - Humidity: - Wind: North at - Pressure: - Hourly Precipitation: - Heat Index: - Graphs

Location: Foster Township, Alton, IL

Updated: 7:50 PM CDT

Temperature: 73.8 °F Dew Point: 70 °F Humidity: 87% Wind: SW at 3.7 mph Pressure: 30.05 in Hourly Precipitation: - Heat Index: 73 °F Graphs

Location: Timber Ridge, Godfrey, IL

Updated: 8:15 PM CDT

Temperature: 73.4 °F Dew Point: 71 °F Humidity: 91% Wind: Calm Pressure: 30.04 in Hourly Precipitation: 0.00 in Heat Index: 71 °F Graphs

Location: Jost Farm, Florissant, MO

Updated: 8:15 PM CDT

Temperature: 72.5 °F Dew Point: 63 °F Humidity: 71% Wind: Calm Pressure: 29.95 in Hourly Precipitation: 0.00 in Heat Index: 75 °F Graphs

Location: MesoWest NAMOK1 IL US UPR, Granite City, IL

Updated: 6:00 PM CDT

Temperature: 71 °F Dew Point: - Humidity: - Wind: Calm Pressure: - Hourly Precipitation: 0.00 in Heat Index: - Graphs

Location: Grand Ave, Edwardsville, IL

Updated: 8:16 PM CDT

Temperature: 71.1 °F Dew Point: 71 °F Humidity: 99% Wind: Calm Pressure: 29.97 in Hourly Precipitation: 0.00 in Heat Index: - Graphs

Location: Knight Compound, Dorsey, IL

Updated: 8:16 PM CDT

Temperature: 73.1 °F Dew Point: 69 °F Humidity: 86% Wind: Calm Pressure: 29.90 in Hourly Precipitation: 0.00 in Heat Index: 72 °F Graphs

Location: Riverwood Place, Florissant, MO

Updated: 8:16 PM CDT

Temperature: 74.4 °F Dew Point: 70 °F Humidity: 86% Wind: Calm Pressure: 30.04 in Hourly Precipitation: 0.01 in Heat Index: 74 °F Graphs

Location: Nickel Plate Trail, Edwardsville, IL

Updated: 8:15 PM CDT

Temperature: 70.8 °F Dew Point: 70 °F Humidity: 97% Wind: Calm Pressure: 30.05 in Hourly Precipitation: 0.01 in Heat Index: - Graphs

Location: EAST GRANITE, Granite City, IL

Updated: 8:16 PM CDT

Temperature: 73.4 °F Dew Point: 71 °F Humidity: 92% Wind: NNW at 2.7 mph Pressure: 30.03 in Hourly Precipitation: - Heat Index: 71 °F Graphs

Location: Dunlap Lake, Edwardsville, IL

Updated: 8:14 PM CDT

Temperature: 71.9 °F Dew Point: 71 °F Humidity: 95% Wind: Calm Pressure: 30.05 in Hourly Precipitation: 0.00 in Heat Index: - Graphs

Location: MesoWest SHPMAN IL US UPR, Shipman, IL

Updated: 7:05 PM CDT

Temperature: 78 °F Dew Point: - Humidity: - Wind: Calm Pressure: - Hourly Precipitation: 0.00 in Heat Index: 76 °F Graphs

Location: Piasa, Piasa, IL

Updated: 8:06 PM CDT

Temperature: 74.5 °F Dew Point: 70 °F Humidity: 85% Wind: Calm Pressure: 30.00 in Hourly Precipitation: 0.02 in Heat Index: 74 °F Graphs

Location: Kelly Greens Weather Station, Edwardsville, IL

Updated: 7:51 PM CDT

Temperature: 72.4 °F Dew Point: 71 °F Humidity: 94% Wind: Calm Pressure: 29.99 in Hourly Precipitation: 0.00 in Heat Index: - Graphs

Location: MesoWest GARD IL US UPR, Hamel, IL

Updated: 7:10 PM CDT

Temperature: 71 °F Dew Point: - Humidity: - Wind: Calm Pressure: - Hourly Precipitation: 0.00 in Heat Index: - Graphs

Location: APRSWXNET Berkeley MO US, Woodson Terrace, MO

Updated: 4:46 PM CDT

Temperature: 80 °F Dew Point: 62 °F Humidity: 55% Wind: SE at 4 mph Pressure: 30.11 in Hourly Precipitation: 0.00 in Heat Index: 81 °F Graphs

Location: Rolling Meadows Dr, Maryville, IL

Updated: 8:16 PM CDT

Temperature: 72.0 °F Dew Point: 70 °F Humidity: 94% Wind: Calm Pressure: 29.44 in Hourly Precipitation: 0.00 in Heat Index: - Graphs

Location: Polestar Boating Center, St. Charles, MO

Updated: 8:16 PM CDT

Temperature: 72.0 °F Dew Point: 70 °F Humidity: 94% Wind: Calm Pressure: 30.09 in Hourly Precipitation: 0.04 in Heat Index: - Graphs

Location: St. Ann, MO, St. Ann, MO

Updated: 8:04 PM CDT

Temperature: 75.0 °F Dew Point: 70 °F Humidity: 83% Wind: North at 1.1 mph Pressure: 29.99 in Hourly Precipitation: - Heat Index: 75 °F Graphs

Location: Liberty Place, Troy, IL

Updated: 8:02 PM CDT

Temperature: 72.3 °F Dew Point: 71 °F Humidity: 94% Wind: Calm Pressure: 29.46 in Hourly Precipitation: 0.01 in Heat Index: - Graphs

Location: Branch Street, St. Louis, MO

Updated: 7:50 PM CDT

Temperature: 76.6 °F Dew Point: - Humidity: 76% Wind: North at - Pressure: 29.61 in Hourly Precipitation: - Heat Index: 78 °F Graphs

Location: Hamel, IL 55/140, Worden, IL

Updated: 8:16 PM CDT

Temperature: 71.8 °F Dew Point: 67 °F Humidity: 86% Wind: WNW at 5.3 mph Pressure: 28.60 in Hourly Precipitation: 0.00 in Heat Index: 70 °F Graphs

Location: BLAIR STREET, St. Louis, MO

Updated: 7:50 PM CDT

Temperature: 75.4 °F Dew Point: - Humidity: 85% Wind: North at - Pressure: 29.54 in Hourly Precipitation: - Heat Index: 76 °F Graphs

Location: MesoWest I -55/64/70 @ Poplar St Bridge IL US ILDOT, Fairmont City, IL

Updated: 7:25 PM CDT

Temperature: 77 °F Dew Point: 71 °F Humidity: 82% Wind: SSE at 4 mph Pressure: - Hourly Precipitation: 0.00 in Heat Index: 79 °F Graphs

Location: Collinsville West, Collinsville, IL

Updated: 8:16 PM CDT

Temperature: 72.3 °F Dew Point: 71 °F Humidity: 95% Wind: Calm Pressure: 30.09 in Hourly Precipitation: 0.00 in Heat Index: - Graphs

MSN Maps of:

Temp: Dew Point: Humidity Wind Pressure Hr Precip -

NWS Forecaster Discussion




Area forecast discussion...updated aviation 
National Weather Service St Louis MO 
552 PM CDT Wed Aug 27 2014 


Short term: (through late tonight) 
issued at 344 PM CDT Wed Aug 27 2014 


Area of showers and thunderstorms over northern Missouri has almost 
totally dissipated as of 20z, and convection has refocused to to the 
south and east along the outflow boundary produced this morning by 
convection over northern Missouri, as well as the very ill-defined 
remains of the surface frontal boundary. Storm coverage should 
remain scattered due to upper level ridging over the area, but 
continue to monitor the stronger storms for an isolated/pulse-type 
severe weather threat over the next hour or two. 


With no upper support, expect this largely diurnally-driven 
convection to dissipate this evening with loss of heating, with 
thunderstorm threat once again shifting back to our northwest 
overnight. Shortwave topping ridge and the associated low level 
forcing/warm advection should lead to a a fairly large convective 
complex forming over the mid Missouri River valley (northwest of our 
fa) during the predawn hours. While the bulk of this activity 
should remain northwest of our forecast area, there should be some 
threat of convection in northern sections of our cwa, either from 
the leading edge of this activity, or perhaps from additional 
convection that will attempt to form in the very weak zone of low 
level warm advection in advance of the complex. 


Truett 


Long term: (thursday through next wednesday) 
issued at 344 PM CDT Wed Aug 27 2014 


Nocturnal convection should be winding down during the morning, but 
not before producing some thunderstorms over parts of central and 
northeast Missouri. It looks like the main area of precip will be 
further west over northwest Missouri again nearest to the low level 
baroclinic zone. With lingering cloud cover and the upper level 
ridge slowly breaking down, expect that temperatures will be cooler 
Thursday than in recent days. With highs ranging from the mid 80s 
to around 90 instead of mid 90s, it looks like heat index values 
will miss the magic 100 degree mark by 2-3 degrees in most 
locations. While still hot and humid, it should feel...less bad. 
Expect widely scattered afternoon thunderstorms to help keep a lid 
on temperatures as well. Will therefore let the heat products 
expire on schedule this evening. 


Thursday night and Friday will be a repeat of tonight and Thursday 
as a weak low level jet provides just enough lift to potentially 
force some isolated to widely scattered convection. With overnight 
lows in the upper 60s to mid 70s and highs Friday in the mid 80s to 
around 90, we should be able to stay heat-headline free. 
Additionally, the trof of low pressure currently spinning over 
southwest Wyoming will be moving into the eastern plains 
Friday/Friday night which will further weaken the upper level ridge 
and allow more widespread convection late Friday afternoon and 
Friday night primarily over central and northeast Missouri. The 
trof will be directly over the County warning forecast area Saturday which should continue 
to produce thunderstorms and keep temperatures suppressed in the 80s. 


Another stronger trof will dig into the Great Plains on Sunday. 
This will keep the upper ridge at Bay and continue to keep 
temperatures in the 80s. Can't rule out a few afternoon 
thunderstorms Sunday as well since the upper ridge will be well to 
our east. The trof continues eastward Sunday night and Monday which 
will bring US increasing chances for rain. Medium range models are 
in decent agreement regarding the cold front associated with the 
trof. It should push into the County warning forecast area late Monday afternoon/Monday 
evening and bringing the threat of more thunderstorms to the area. 
Models stall the front out over southern Missouri Tuesday and then 
allow it to creep back to the north Wednesday. This won't be a big 
blast of cold air behind the front...rather just enough cool air to 
bring temperatures down to near or slightly below seasonal normals. 


Carney 


&& 


Aviation: (for the 00z tafs through 00z Thursday evening) 
issued at 525 PM CDT Wed Aug 27 2014 


Most of the convection impacting the St Louis Metro area should 
dissipate early this evening with the loss of daytime heating. 
Mainly just mid-high level clouds for the remainder of the night 
with most of the nocturnal convection remaining north of the taf 
sites, although there may be a few storms impacting the uin area 
towards morning. There will likely be some fog late tonight/early 
Thursday morning in cou and the St Louis Metro area with light 
surface winds and high surface dew points, particularly in areas 
which had recent rainfall. Surface winds will pick up from a sely 
direction on Thursday as the surface ridge centered over the Great 
Lakes region shifts slowly eastward. Scattered diurnal cumulus 
clouds will develop again late Thursday morning and afternoon 
along with at least isolated afternoon and early evening 
thunderstorms. 


Specifics for kstl: thunderstorms should dissipate early this 
evening, by 01z or 02z. Mainly just mid-high level clouds for the 
remainder of the night with fog possible late tonight/early 
Thursday morning. The surface wind will diminish and become light 
later this evening, then pick up to around 8 kts Thursday 
afternoon from a sely direction. There will likely be isolated to 
scattered thunderstorms Thursday afternoon into the early evening. 


Gks 


&& 


Preliminary point temperatures/pops: 
Saint Louis 76 91 76 90 / 30 40 20 20 
Quincy 69 87 71 88 / 20 50 30 30 
Columbia 72 92 71 88 / 20 30 20 40 
Jefferson City 72 92 72 89 / 20 20 20 40 
Salem 71 89 71 89 / 30 40 30 20 
Farmington 71 90 70 88 / 30 20 10 20 


&& 


Lsx watches/warnings/advisories: 
MO...heat advisory until 8 PM CDT this evening for Audrain MO-Boone 
MO-Callaway MO-Cole MO-Crawford MO-Franklin MO-Gasconade MO- 
Iron MO-Madison MO-Moniteau MO-Montgomery MO-Osage MO- 
Reynolds MO-St. Francois MO-Ste. Genevieve MO-Warren MO- 
Washington MO. 


Excessive heat warning until 8 PM CDT this evening for Jefferson 
MO-Lincoln MO-St. Charles MO-St. Louis city MO-St. Louis MO. 


Illinois...excessive heat warning until 8 PM CDT this evening for Bond Illinois- 
Calhoun Illinois-Clinton Illinois-Fayette Illinois-Greene Illinois-Jersey Illinois- 
Macoupin Illinois-Madison Illinois-Marion Illinois-Monroe Illinois-Montgomery Illinois- 
Randolph IL-St. Clair Illinois-Washington Illinois. 


&& 


$$ 


Weather forecast office lsx 












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