Interpreting weather forecasts

bigmonka

Has anyone got any good tips for interpreting weather forecasts to know whether the weather ( :? ) is suitable for cycling or not?
I normally chicken out if its been below 2degC overnight and isn't forecast to be more than 3degC at commuting time. I had a few offs on patches of ice few years ago and it's left me probably overly cautious. I guess I'm just looking for advice that'll help me say "MTFU" to myself on those cold mornings!

IanLD

If it has been dry for the past few days then there should only be some frost if it is -3 or so. That's fine to ride on but treat it with respect when braking and cornering. Gritted roads will be fine.

Main thing to watch for is frozen run off and puddles. This can linger much longer and still be frozen when returning in the evening. That's where studs will be of benefit.

I'm trying to work out what it is going to be like tomorrow as I really don't want to put the studs back on. I know where to expect icy patches on my 23 mile return run (5 miles in the morning to station) and driving part of the route today things seemed fine.

If you are familiar with where the puddles form and where you get run off, you should be able to work out where to avoid or even walk over. At this time of year the sun is now strong enough to dry out the surfaces during the day and without any rain or snow they should be ok.

ricky1980

use met office 5 day forecast
sunny means sunny
sunny/overcast means overcast all day
overcast means light rain
overcast+light rain means light to heavy rain
light rain means it's pouring or torrential
shower means you are going to get a good soaking, if you don't want your cloths wet, then ride naked
snow/light snow means it ain't going to snow
snow storm means there will be light snow
ice/sleet means its going to be pouring and the rain is going to feel like needle on the face

Wind speed and gusts - add another 10mph onto the values

the general theme is if Met predicts nice weather, take it down a notch. if Met predicts fun weather (snow), it is not going to be as much as fun as you expect.

bigmonka

ricky1980 wrote:

the general theme is if Met predicts nice weather, take it down a notch. if Met predicts fun weather (snow), it is not going to be as much as fun as you expect.

At least them sound predictable in their incorrectness!

ricky1980

BigMonka wrote:

ricky1980 wrote:

the general theme is if Met predicts nice weather, take it down a notch. if Met predicts fun weather (snow), it is not going to be as much as fun as you expect.

At least them sound predictable in their incorrectness!

yep they are certainly consistently wrong

bigmonka

IanLD wrote:

If it has been dry for the past few days then there should only be some frost if it is -3 or so. That's fine to ride on but treat it with respect when braking and cornering. Gritted roads will be fine.

So would/do you ride on frosty roads (and not on a mountain bike with fat tyres or studs)? I've always thought frost would be too slippery.

That's a good suggestion about learning where run-off will freeze - there are certain places which I know will flood when it rains heavily, now I've got my next thing to learn!

menthel

I ignore the forecast and just expect the worst. When I do go outside and its nice I am pleasantly surprised!

IanLD

BigMonka wrote:

So would/do you ride on frosty roads (and not on a mountain bike with fat tyres or studs)? I've always thought frost would be too slippery.

That's a good suggestion about learning where run-off will freeze - there are certain places which I know will flood when it rains heavily, now I've got my next thing to learn!

If it has been dry then frost is not so much of a problem. Tyre contact patch is tiny, so it presses down hard and cuts through. Still best to be cautious on corners and braking zones.

Completely different if it has been wet. Frost will mean ice and that needs studs to be sure of getting grip.

I used to ride on ice when I rode tubs in my racing days and never came off (not on ice, just wet diesel and gravel), but don't risk it now on any of my bikes. I've tried Continental Winter Contact II on my hybrid, but have not given it a good ride on ice. Small patches of run off I hit on cambered road still had me sliding and I didn't like it. Studs slid much much less but bike can still move around a bit.

Rode today in freezing conditions when I set off, but sun had already burnt the frost off. Return journey between 19:00 and 21:00 tonight was fine as all run off was still wet, but I made sure it was where I expected it to be.

Study your route carefully to learn where the hazards are. If in doubt, take the car, train or bus and you'll be in one piece to tackle it another day.

As a matter of interest, what size of tyres can you fit on your bike(s). That would open up some possible options.

bigmonka

Thanks for the reply. I've considered studs before but have never taken the plunge. In theory all my commute (15mile round trip) is on the primary gritter route so I'd be riding studs on mainly dry roads most of the time - not sure how good that would be?

I've only got one bike, which is a Revolution Courier Race Disc 12 (short catchy name!), which according to the website has:
Hubs : Formula 6-Bolts, 32h Front, 32h Rear, Black Alloy, Anodised Red Quick Releases
Rims: Revolution, Alloy, Urban Series

I've no idea how to convert that into knowing what size tyres I can fit! (they're currently 700x28c tyres)

bigmonka

It was round about 0degC this morning but I did it on the bike. To be honest it is so dry (and no frost) that there wasn't a problem at all. But I wore so many layers thinking I would freeze that I turned up at work really sweaty!