Valle Crucis NC Weather

Summary

SYNOPSIS

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High pressure passing overhead to the east will provide dry weather for most locations through tonight. Increasing moisture pooling ahead of an approaching cold front will bring widely scattered showers and thunderstorms for Wednesday and Thursday. This activity will increase in coverage through the weekend as the low pressure system tracks toward the eastern United States.

NEAR TERM /THROUGH TONIGHT/... As of 1215 PM EDT Tuesday...

Key messages:

- Confidence moderate for isolated thunderstorms this afternoon - Confidence high for above normal temperatures today and tonight

Satellite imagery depicts scattered fair weather clouds across the region this afternoon, with more pronounced development along the higher ridges west of the Blue Ridge. Still, abundant sunshine has allowed temperatures to warm into the 70s for most of the region, with a few 80 degree observations across the Southside area.

Rapid update weather models still hinting at the development of a few showers and isolated thunderstorms developing across the mountains after 3 pm. This activity is expected to remain progressive, resulting in relatively brief periods of rainfall, with mainly a tenth of an inch or less in accumulation where it does manage to develop. Most of the lower Mid-Atlantic area will top out in the upper 70s to the low 80s for highs.

For tonight, showers will fade quickly with the loss of daytime heating as sunset approaches. With light winds and mostly clear skies overtop moist soils from recent rainfall, patchy fog will redevelop after midnight, particularly in the river valleys. Overnight lows will bottom out in the mid 50s to around 60 degrees.

SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/... As of 200 AM EDT Tuesday...

Key Points:

1. Well above normal temperatures for this time of year. 2. Scattered showers and storms Wednesday mainly across the mountains. 3. Robust coverage of showers and storms Thursday and Friday, especially during the afternoon hours over the mountains.

A look at the 20 May 00Z NCEP Ensemble Mean 500 mb Geopotential heights shows for Wednesday high pressure in the western Atlantic, off the coasts of the Carolinas and a shortwave trough extending form MN southeast into IN. By Thursday, this axis of the shortwave trough will be over our region, and by Friday, it will be over the Canadian Maritimes. At the surface, on Wednesday, low pressure will be centered near the Ontario/Quebec border with an associated cold front curving southwest into parts of MI/WI/IA. By Thursday, the low shifts into northern Quebec with the cold front crossing our region. On Friday, the low makes additional progress eastward, but its front is not as progressive and begins to stall over the region.

Output from the 20 May 12Z Ensemble Situational Awareness Table shows 850mb temperatures around +16C across the area Wednesday and Thursday, or values with the 90 to 97.5 percentile of the 30-year climatology. On Friday, values are slightly cooler in the +14 to +16C range. On Wednesday Precipitable Water values will range from 1.00 to 1.25 inches, for Thursday, 1.50 inch which falls with the 90 to 97.5 percentile of the 30-year climatology, then back to around 1.25 inches by Friday.

The above weather scenario will offer increasing chances of showers and storms on Wednesday, especially across the mountains. By Thursday into Friday, look for robust coverage across the region, especially across the mountains during peak heating of the day as a cold front crosses and then stalls over the area. Given the above normal PW values over the are on Thursday, expected rainfall Thursday into Friday may need to be monitored for locally heavy rain concerns, especially if the same locations have repeated heavy rain. Temperatures will be well above normal for this time of year.

Confidence in the above weather pattern is moderate to high.

LONG TERM /SATURDAY THROUGH MONDAY/... As of 200 AM EDT Tuesday...

Key Points:

1. Temperatures continue above normal for this time of year. 2. Potential for daily chance of showers and storms 3. Confidence in the specific timing and location of the precipitation is low.

A look at the 20 May 00Z NCEP Ensemble Mean 500 mb Geopotential heights shows the region in a general southwest flow pattern as a trough deepens across central CONUS. Concurrently, heights will trend slightly higher each day over the region. At the surface, indications are the surface front that began to stall over the area on Friday, continues over or near the area on Saturday as the parent low races away to south of Greenland. Sunday and Monday, the averaging process of the ensemble solution washes out its earlier weak signature of a front over the area. However, there are good signs of a generally troughiness across the central US.

Output from the 20 May 12Z Ensemble Situational Awareness Table shows 850mb temperatures average +16C through the period. Precipitable Water values will average 1.25 inches through the period.

The above weather scenario may present a continuation of daily chances of showers and storms. The challenge in just where the frontal boundary from Friday moves to, or doesn't move. Additionally, the prevailing southwest flow aloft could help escort shortwave troughs across the region from the generally area of troughiness across the center of the nation. While this general pattern may end up being accurate, at this time, nailing down the details in the timing of the best chances of precipitation each day is the biggest question mark. As such, confidence in this portion of the forecast is low on these details. There is better confidence in the continuation of above normal temperatures