2026-2027 Fall/Winter Mountain Thread

[Met1985]

With this now a major hurricane this thing is coming east as noted above.  That will really put us here in WNC in the bullseye in my opinion.  Also we've seen this before but in situations like this the models underperforme on precipitation amounts.  Also keep an eye out on sustained winds and wind gusts. 

[wncsnow]

Sure looks like this will be our heaviest rain event since Helene along the escarpment. I just wonder if there will be any new landslides where the soil is still loose from last time. 

[Maggie Valley Steve]

High Wind Warning hoisted for the WNC Mountains above 3500 ft from midnight tonight until Sunday morning. Wind Advisory hoisted for the Mountains below 3500 ft for the same timeframe.

[Tyler Penland]

22 minutes ago, Maggie Valley Steve said:

High Wind Warning hoisted for the WNC Mountains above 3500 ft from midnight tonight until Sunday morning. Wind Advisory hoisted for the Mountains below 3500 ft for the same timeframe.

Based on their graphics out right now I don't foresee them issuing a Flood Watch. Hope that doesn't come back to bite them. 
 

Looking more likely that Isaias won't have time to weaken significantly before landfall and the continued east-of-track motion is aligning it more with the shear vs running into it. When the mid-level winds run into the mountains its going to be a fun time.

[Maggie Valley Steve]

Updated Excessive Rainfall Outlook from the WPC. Folks need to be aware of the Flooding possibility with this storm.

[strongwxnc]

27 minutes ago, Maggie Valley Steve said:

Updated Excessive Rainfall Outlook from the WPC. Folks need to be aware of the Flooding possibility with this storm.

 

Base off GSP chat I think they will be issuing something this afternoon.. 

[WNC_Fort]

7 minutes ago, strongwxnc said:

Base off GSP chat I think they will be issuing something this afternoon.. 

remind me where I’d find that chat?

[Maggie Valley Steve]

10 minutes ago, strongwxnc said:

Base off GSP chat I think they will be issuing something this afternoon.. 

I was part of NWS chat for many years at HGX before moving up here. Keep us posted.

[wncsnow]

It's hard to believe we aren't even under a flood watch. 

[strongwxnc]

NWSGSP

 

I have an account via the school system I work for. 

I only ever connect during weather events.

[GoAPPS]

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
104 PM EDT Fri Oct 9 2026
Day 2
Valid 12Z Sat Oct 10 2026 - 12Z Sun Oct 11 2026

...THERE IS A MODERATE RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
THE SOUTHEAST UNITED STATES...

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR SOUTHEAST
CALIFORNIA AND FAR SOUTHERN NEVADA...

...Southeast (Isaias)...

...1700Z Update...
A Moderate Risk of Excessive Rainfall was introduced for portions
of the western Carolinas southward into northern Georgia given
latest QPF trends. Additional details will follow shortly.

Bann

Previous Forecast Discussion...

The threat of heavy rainfall and flash flooding from Isaias will
continue over a large portion of the Southeast on Saturday and
Saturday Night. The latest outlook is very consistent with the
previous forecast, with mostly small changes to account for the
latest guidance and updated forecasts from NHC. See
www.hurricanes.gov for the latest forecast information on all
hazards associated with Isaias.

Although the Slight Risk area is large, there are several areas of
note where the threat is somewhat higher (on the high end of the 15
to 40 percent probabilistic range associated with that risk
category), and could warrant an upgrade to a Moderate Risk in the
future if guidance becomes more consistent and/or the potential for
locally significant rainfall and flash flooding increases.

1. Convective rain band east of the center of Isaias (Florida Big
Bend into much of Georgia). There is high confidence in a
convective rain band setting up about 200 miles east of the track
of the center of Isaias. This will ramp up Friday Night and likely
be ongoing on Saturday morning. Given the access to moderate
instability and precipitable water values approaching 2.5 inches,
the rain rates could be intense at times (2-3 inches per hour). The
key uncertainties are how far north the strongest convection will
be able to reach, and how stationary the band will be overall. The
00Z HRRR suggested some northern limit to the extent of the
instability due to a wedge of cooler air associated with a surface
ridge and northeasterly low-level flow from the Piedmont of the
Carolinas down into northern Georgia. However, other models suggest
the effective warm front will lift further north and bring
locations near Atlanta under risk of greater rain rates. This will
be monitored for the need for a risk upgrade.

2. Southern Appalachians (far northeast Georgia, far upstate South
Carolina, western North Carolina). Model QPF has been increasing in
general in this region; for example, the NBM QPF in the upslope
areas of western North Carolina has increased from a general 1-3
inches to 3-5 inches in the past 12 hours of updated runs. A
contributing factor is the event coming into view of the hi-res
model runs, of which many are showing more terrain enhancement and
a wetter forecast, but there are some overall adjustments to the
ensemble envelope with some trends in the overall forecast of
Isaias. Not all hi-res models are suggestive of the highest rain
rates reaching this region -- the 00Z HRRR kept instability
suppressed further south with a wedge of cooler air in place closer
to the mountains. However, other hi-res models are beginning to
suggest double digit totals are not out of the question depending
on the mesoscale details (particularly strength and orientation of
the low-mid level flow and available instability). It is noted here
that a Moderate Risk upgrade was strongly considered, but after
collaboration with WFO GSP and the uncertainties described here,
it was held at a high-end Slight Risk for now. Continued model
trends in a wetter direction and reduction in rainfall uncertainty
would likely drive an upgrade later today.

...