An updated amber alert comes into force at 5am on Friday (February 18) with warnings of danger to life, damage to buildings and power cuts from 80mph gusts blowing across the county.
Local weather watchers say the 'significant weather event' could produce some of the strongest winds to hit the county for many years.
Emergency services and engineers are on standby while train companies have cancelled a string of services.
Forecasters @NNweather said: "The Met Office warning impact matrix now shows we are one step away from a rare red warning being issued.
"The risk of a significant weather event in the county on Friday looks very likely.
"A concerning development on one overnight model run is what potentially maybe a sting jet’ — a small area of very intense winds — bringing a short spell of 100mph gusts.
"Hopefully this will not happen but Storm Eunice may produce some of the strongest winds to impact the county for many years, peaking around the middle of the day."
Here's what to expect from Storm Eunice on Friday:
■ A good chance that flying debris could result in a danger to life
■ Damage to buildings and homes is likely, with roofs blown off and power lines brought down
■ Roads, bridges and railway lines are likely to close, with delays and cancellations to bus, train, ferry services and flights
■ A good chance that power cuts, possibly prolonged, could occur and affecting other services such as mobile phone coverage
■ It is likely there will be falling branches and some uprooted trees
Power cuts were reported in some villages in the county as Storm Dudley's winds hit on Wednesday and Western Power Distribution, which manages the electricity supply network, says additional engineers are on stand-by to respond to reports of power lines down.
A spokesman said: "We know that storm conditions can be a worrying time for our customers, so we have put a range of measures in place to ensure we’re ready for any impact on the electricity network."
■ Click HERE for tips to prepare in case of a power cut
National Highways has warned gusts could be strong enough blow over motorcyclists, trailers and high-sided vehicles on exposed routes.
A Northamptonshire Highways spokesman said: "We are on standby should we need to respond to issues due to the weather and high winds.
"Please drive carefully and be aware that trees may be down. If you have any concerns, just let us know via Street Doctor online.
East Midlands Railway says it will operate an hugely reduced timetable from Corby, Kettering and Wellingborough but still expects short-notice cancellations, delays and extended journey times with speed restrictions on most routes.
London Northwestern Railway, which runs services to and from London Euston and the North West via Northampton, is advising passengers not to travel unless absolutely necessary.
County health chiefs have also shut down a mobile vaccination clinic until Saturday as a precaution at Corby's Adrenaline Alley skate park.
Lyveden National Trust, a popular destination for half-term days out between Thrapston and Oundle, has also said it will be closed on Friday.