It's good to see you are willing to prepare nearly a year in advance. The conditions and whether an April ascent via the MWMT is feasible are completely dependent on what happens this winter. In some leaner snow years, the MWMT is passable. If there is decent snow (which CA needs) the MWMT would be a very long snowshoe approach and a treacherous journey from Trail Crest to the summit.
Remember, it hasn't been uncommon to deal with significant patches of snow on Whitney in July, so an especially snow-bound April isn't off the table.
If you are already going in the snow I would prepare for the Mountaineers Route. It's steeper but shorter and you're more likely to see more people there in April.
Regardless of which route you do you need to have good mountaineering boots, crampons that fit and you are comfortable with. You must know how and when to use those crampons including how to flat-foot (French technique), front-point (German technique), and change direction on steep slopes. You must also be proficient in axe work: self-belay, glissading, and
especially self-arrest. Also
take an avalanche class. Folks die of an avalanche during the Sierra spring in fat and lean snow years alike. You should be able to decipher avalanche conditions ahead of your trip and monitor snow conditions on the day while you are on the mountain during that time. If it is a big snow year you may need to invest in and practice wearing snowshoes too. All of these skills are essential big mountain skills you should know. You can learn and self-teach over the coming winter, but having a mentor to guide and practice with you is very important. I know so many folks who think they know how to do these things but don't because many of these skills aren't intuitive. I had a stranger try to correct my glissade technique on Shasta 5 years ago with an incorrect method. I tried to explain why he was mistaken but he dismissed me and took off on his glissade: he ended up sliding out of control, losing his axe, and had to abort his glissade, backtrack to his axe, and walk out (too afraid to glissade). He was okay, but I finished several hours earlier than he did. It bears repeating: get and practice good techniques from people who know their stuff.
Gate and road closures are also issues you will deal with from October through June dependent on snow. In some cases, the road will be closed due to snowfall or rockfall. Some folks are prepared for hiking into the Portal, but the unsuspecting may be thwarted in getting near the summit by being unprepared for these closures.
All that said, this is the checklist I'd give you to prepare for an early-season ascent:
- Get in GREAT hiking shape to tackle snowy steeps (6k ascent in 5 miles).
- Hone your crampon, axe, and avalanche skills.
- Prepare to have and use snowshoes if conditions mandate it.
- Acclimatize on the highest mountains near you.
- Prepare to hike the road in due to closures.
- Be prepared to fail. Spring weather and avalanche conditions can be exceedingly dangerous. Preparation is just as much about being prepared to succeed as it is knowing when to bail out.
I know this is a long, worst-case scenario list but fortunately, you have months to prepare. Winter is coming so you can get used to potential conditions. If we end up having a low snow year you will be super prepared and have a much more relaxed time in the Whitney Zone.
Cheers, and good luck!
