textproduct: Raleigh

WHAT HAS CHANGED

* Heat Advisories will be needed at least through Friday.

* An isolated strong storm is possible, mainly in the NE Coastal Plain this afternoon.

KEY MESSAGES

As of 251 AM Wednesday...

1) A Heat Advisory has been issued for Wednesday 11 AM until 8 PM. Anomalously hot temperatures are expected to persist into Friday and possibly Saturday. Heat Advisories will be needed.

2) Labor Day weekend through Monday gradually trends cooler along with highest thunderstorm chances Friday and Saturday.

DISCUSSION

As of 251 AM Wednesday...

KEY MESSAGE 1... A Heat Advisory has been issued for Wednesday 11 AM until 8 PM. Anomalously hot temperatures are expected to persist into Friday.

The Heat Advisory is in effect for most of the eastern Piedmont through the Sandhills and Coastal Plain.

Even at this late hour (or early for some) - at 200 AM - it was still 80+ degrees in the urban centers of the Triad, Triangle, and Fayetteville. We will definitely be off and running when the sun rises. Expect mostly sunny skies and highs in the 97-100 range in most areas. Heat index values will very near 100 in the NW and 105+ in the advisory area this afternoon.

Lows tonight will be in the mid to upper 70s. Again, it will be slow to fall below 90 this evening, and 80 at 300 AM Thursday.

Expect additional Heat Advisories the rest of the work week.

There is a slight chance of PM thunderstorms this afternoon, mainly in the NE Coastal Plain, where some weak convergence with the surface trough may work with MLCapes in excess of 2500 J/kg to force a storm or two this afternoon. We do not expect anything more than isolated storms this afternoon.

There is a slight chance of PM storms again during peak heating Thursday; however, the chance is essentially over and near the mountains with differential heating. KEY MESSAGE 2...Labor Day weekend through Monday gradually trends cooler along with highest thunderstorm chances Saturday - shifting SE Sunday and Monday.

The chance of thunderstorms will go up somewhat Friday, mainly in the north and east as some upper level energy over the mid-Atlantic states may send outflows from VA convection into the region late in the day.

The highest chance of thunderstorms appears to be Saturday as the backdoor front and outflows work through the region during the afternoon and evening. It will remain hot and become unstable aiding in the low level forcing with the boundaries to work with.

The chance of showers/storms is expected to shift to the southeast and over the mountains Sunday and Monday as a cooler and more stable NE flow sets up. Highs in the 80s and lows in the 60s will be much more tolerable for most!

AVIATION /12Z WEDNESDAY THROUGH SUNDAY/

As of 643 AM Wednesday...

Generally VFR conditions are expected through 12z/Thursday.

Looking beyond 06z Thu, terminals are likely to stay dry and VFR through Fri morning, although the chance for mainly afternoon and evening showers and storms will increase Fri afternoon and remain high Sat and Sun as a cold front slips southward into NC.

CLIMATE

Our forecast highs and lows are within about 3 degrees of the daily records listed below.

Record High Temperatures:

September 2: KRDU: 99/1912

September 3: KGSO: 101/1921 KRDU: 99/2010 KFAY: 101/2010

September 4: KGSO: 100/1925 KRDU: 100/1925 KFAY: 100/1944

September 5: KRDU: 98/2023 KFAY: 99/1932

Record High Minimum Temperatures:

September 2: KGSO: 73/1912 KRDU: 75/1912 KFAY: 75/2020

September 3: KGSO: 73/2020 KRDU: 78/1933 KFAY: 77/2020

September 4: KGSO: 72/2018 KRDU: 74/1921 KFAY: 75/2020

September 5: KGSO: 73/2018 KRDU: 74/2012 KFAY: 74/1935

RAH WATCHES/WARNINGS/ADVISORIES

Heat Advisory from 11 AM to 8 PM EDT Wednesday for NCZ010-011- 024>028-040>043-075>078-084>086-088-089.