Mt Whitney Zone Forums General Discussion Contradicting info between NOAA and mountain-forecast

Be careful about mountain-forecast predictions. They are computer generated without much human review. They're trying really hard to make detailed adjustments for mountain terrain. I would consider them experimental, but useful if you combine with other forecasts.

I'm not an expert, but here's how I would interpret this weekend on Mt Whitney:

mountain-forecast predicts no precipt on Saturday and 0.4" of snow Sunday PM at 4418m with is AT THE SUMMIT. PM means sometime between noon and midnight. Converting 0.4" to rain is about 0.05". Either way, its just a trace of precip.

NWS also attempts pin-point forecasts adjusted for elevation. Default location is 12,000 ft (Trail Camp). They are forecasting a slight chance to 20% chance of rain or snow starting after 11am Saturday all through the weekend.

Accuweather for Whitney Portal forecasts a "shower in spots" 0.04" Saturday and Sunday afternoon.

1. Looks like a small storm system is moving into the area. 2 models predict it will arrive Saturday around noon. The other model predicts it will arrive Sunday afternoon.

2. Precip amounts are very small for all 3 models, a few hundreds of an inch. Could be some snow or sleet mixed in at upper elevations near the summit. Some afternoon thunder is mentioned and I would expect that even if it doesn't rain.

3. Wind forecast for all 3 models is light (5-15 mph). Always anticipate winds on the summit.

4. All temps are above freezing, but I'd be ready for 32F at night.

All in all, the 3 forecasts are not that far off, and taken together, they paint a clear picture of what to expect - a mildly stormy weekend, mostly cloudy, occasional light rain, perhaps sleet or snow on upper mountain but no large amounts expected, generally breezy, windy at summit, day temps 40s and 50s, near freezing over night. Not bad for climbing if you bring the right layers. Could be some nice partly cloudy skies for good pictures at times.

This wouldn't worry me at all. It should be within your expectations for September. Have a great trip.