Marine Weather and Tide Forecast for Lake Norman of Catawba, NC

NEAR TERM /THROUGH TONIGHT/
As of 230 AM EDT Tuesday...

Key Messages:

1) A Few Showers and Thunderstorms Possible this Afternoon with Better Coverage Expected this Evening into Tonight Ahead of a Strong Cold Front

2) Strong to Severe Storms are Possible, Mainly this Evening into Tonight, Especially Over the North Carolina Mountains

3) Warm Again with Above Normal Temperatures

Upper ridging remains over the Southeast through the near term. At the sfc, a frontal boundary will remain stalled over the western Carolinas this morning before lifting north this afternoon and evening while reactivating as a warm front. Meanwhile, a cold front will approach out of the rest through late tonight before tracking across the western half of the CWA overnight. Although mostly quiet weather is expected through late this afternoon, the forecast becomes more active this evening into tonight ahead of the cold front. Temperatures will remain a few to several degrees above normal through the near term.

It will be another warm and humid day with temps climbing into mid to upper 80s across NE GA and the SC Upstate and the low to mid 80s across the lower elevations in western NC. Highs across the higher elevations in western NC will be cooler, ranging from the mid 60s to mid 70s. CAMs continue to show the potential for some light rain this morning but confidence on whether this will reach the ground remains low. Thus, capped PoPs to chance (24% or less) through the morning hours. 00Z CAMs generally agree that shower and thunderstorm chances will be suppressed through the late afternoon hours, with isolated to widely scattered activity developing by this evening. Can't rule out an isolated strong to severe storm or two this evening, especially with SBCAPE up to 1,500 J/kg and deep layer shear from 40-50 kts in place, but confidence is low.

Confidence on the severe weather potential increases late this evening into tonight ahead of the cold front. However, the severe potential may be limited by two things; 1) activity coming through outside of peak heating hours and 2) the better instability remaining just ahead of the storms. The 00Z CAMs still show some slight timing differences regarding when showers and thunderstorms will push across the forecast area. However, the overall consensus is that activity will push into the mountains anywhere from 11pm to 1am with locations east of the mountains seeing activity push in from 2am to 4am. CAMs also show a weakening trend with activity as it pushes across the NC mountains. How much storms will weaken (as well as how fast they will weaken) continue to be the main forecast challenge. The 00Z HRRR shows activity holding together across much of western NC overnight into early Wednesday morning with activity falling apart across NE GA and the SC Upstate. Meanwhile, the 00Z NAMNest shows activity falling apart quickly once it pushes off the NC mountains. So, confidence on the severe potential remains low east of the mountains but will generally be higher across the NC mountains. SPC expanded the slight risk farther east (it now includes most of the forecast area with the exception of locations along and east of I-77) as well as an upgrade to an enhanced risk across western Graham and Swain counties. Damaging winds and large hail will be the two main hazards with any severe storms that develop. However, an isolated, brief tornado or two cannot be ruled out, especially across the southern NC mountains.

SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/
Key Messages:

1) Drier conditions gradually return Wednesday with gusty winds

2) Temperatures begin to cool down Thursday

As of 140AM EDT Tuesday: Zonal flow aloft begins the period with westerly winds and a weak cold front pushing across the CWA
Guidance has lingering showers quickly diminishing as the drier air undercuts it. Meanwhile, guidance from the GFS/EURO put a strong upper low over the Great Lakes with a broad trough dipping southward. Given the tight gradient at the 850mb level, this could bring some gusty winds across the area, especially the mountains on Thursday. At this time, the higher elevations have about a 40-50% chance of exceeding 45 mph, with other locations in the mountains being less than 20%. Will continue to monitor as confidence is low at this point for any wind products. With this trough dipping down, a swath of DPVA crosses the mountains as well and guidance wants to increase shower chances (20-40%) along the TN/NC border. This continues through the end of the period on Thursday night.
Additionally, the drier, cooler air brings temperatures closer to normal by Thursday and begins a cooling trend into the next period.

LONG TERM /FRIDAY THROUGH MONDAY/
Key Messages:

1) A drier air mass keeps temperatures below normal into Memorial Day Weekend

2) Shower and thunderstorm chances are possible Sunday into Monday

As of 200 AM EDT Tuesday: From Friday onward, long range guidance essentially puts the area int a quasi-zonal pattern with small areas of DPVA sliding toward the southeast through the weekend. Some guidance hints at possible shower chances, especially across the mountains. Sunday and into Monday could have more shower chances and coverage as the NBM tries to slide a system of precipitation towards the area. The QPF response isn't much at this time as there is still too much uncertainty. However, the holiday weekend could see showers and thunderstorms toward the end of the period. Overall, the pattern looks less then primed for strong convection outside of diurnally driven pop-up showers typical for summertime. Temperatures for the extended look near normal with a slow, gradual warming through the end of the forecast period.

AVIATION /08Z TUESDAY THROUGH SATURDAY/
At KCLT and elsewhere: Light -RA is possible through mid-morning across the terminals but confidence remains too low for a mention at this time. Mostly dry conditions are expected to continue through much of the TAF period, although a line of SHRA/TSRA will push towards the terminals near the end of the 06Z TAF period. Thus, have PROB30s everywhere to account for TSRA and associated restrictions this evening into late tonight. VFR should prevail most of the period outside of SHRA/TSRA. Winds will be calm through the early morning hours. Winds east of the mountains will pick up out of the NE by daybreak. NE winds will continue east of the mountains through the morning hours before winds gradually turning more S'ly this afternoon into tonight. Winds at KAVL will pick up out of the SE this morning, gradually turning more S'ly through this afternoon.

Outlook: SHRA/TSRA and associated restrictions stick around through the overnight hours before drier and VFR conditions return Wednesday into the first half of the weekend. Mountain valley fog and low stratus will be possible each morning.

GSP WATCHES/WARNINGS/ADVISORIES
GA...None.
NC...None.
SC...None.