#Call the website and load into our page variable
$page = Invoke-WebRequest "http://www.accuweather.com/ajax-service/find-minutecast-location?query=norfolk,va&address=Norfolk,%20VA&lat=36.84682083129883&lon=-76.2850570678711&languageID=1"

#Looking at the result via a brower I was able to locate the data chart about 2/3 of the way down
#Doing a VERY quick regex, you can come up with the following
$regex = [regex]'"time">(?<time>\d+\:\d+).+"type"><p>(?<rain>.+)</p>'

#Take our regex, find the matches on the page and loop through them
$results = $regex.Matches($page.Content) | % {
# create a custom object with the results
[pscustomobject]@{
    Time  = $_.Groups[1]
    Rain  = $_.Groups[2]
}
}
# for now display the results in a table autosized to contents
# $results | ft -AutoSize
[bool]$willrain = $false
$timerainstart = $null
$timerainstop = $null
$typeofrainstart = $null
$typeofrainstop = $null
Foreach ($res in $results){
If ($res.Rain.Value -eq "No Precipitation")
{
    If ($willrain -eq $true){
        if($timerainstop -eq $null){$timerainstop = $res.Time.Value}
    }
}else{
    if ($willrain -eq $true){
        $timerainstop = $res.Time.Value
        $typeofrainstop = $res.Rain.Value
    }else{
        $timerainstart = $res.Time.Value
        $typeofrainstart = $res.Rain.Value
        $willrain = $true
    }
}
}
If ($willrain -eq $false){
    Write-Host "Looks clear for the next two hours";
}else{
        If($timerainstop){Write-Host "$typeofrainstart starting at $timerainstart and ending with $typeofrainstop at $timerainstop"
    }else{Write-Host "$typeofrainstart starting at $timerainstart - in 120 minutes - $res.Rain.Value - unknown stop time"}
}