textproduct: Raleigh

WHAT HAS CHANGED

* Dense Fog Advisory issued until 9 AM for portions of the northern Piedmont and northern Coastal Plain.

KEY MESSAGES

As of 300 AM Tuesday...

1) Dense Fog Advisory issued until 9 AM for portions of the northern Piedmont and northern Coastal Plain.

2) A chance of showers/isolated thunderstorms Wednesday afternoon and evening.

3) A typical, summertime pattern will develop across the South Atlantic states later this weekend through (at least) early next week.

DISCUSSION

As of 620 AM Tuesday...

KEY MESSAGE 1... Dense Fog Advisory issued until 9 AM for portions of the northern Piedmont and northern Coastal Plain.

Dense fog has developed across portions of the nrn Piedmont and nrn Coastal Plain. Patchy dense fog is possible outside of the advisory area. Conditions should improve by 9 AM. Folks along the NC/VA border should be prepared for possible slower travel during the morning commute.

KEY MESSAGE 2... A chance of showers/isolated thunderstorms Wednesday afternoon and evening.

A s/w aloft will swing ewd across the region Wed/Wed night, while a low is expected to close off within the trough over the Northeast US/nrn mid-Atlantic on Thu. At the surface, as the high shifts farther offshore on Wed, the ridge extending wwd into the region between a low off the Southeast US coast and a cold front approaching from the NW will weaken. The cold front should move across the area Wed eve/night and be off the Carolina coast by Thu morn. Cool high pressure will gradually build ewd into the region in Thu/Thu night. Given the current expected fropa timing, temperatures should be able to rise into the mid 70s to low 80s Wed aft. However, there is some uncertainty wrt the moisture recovery Wed, between the departing high/weakening ridge and the approaching cold front. The available moisture will play a role in how much instability there is to work with as the front moves in Wed eve. The NAM forecast soundings show deep layer shear of 40-50+ kts, however the SBCAPE is limited to generally less than 500 J/Kg, with diurnal timing of the front and associated convection near or after sunset. Showers and isolated storms are expected and while not likely, given the strong kinematic profiles a strong wind gust or two cannot be completely ruled out should any deeper storms develop.

KEY MESSAGE 3... A typical, summertime pattern will develop across the South Atlantic states later this weekend through (at least) early next week.

A mid-level anticyclone, centered in 00Z/12th 700 mb data at 320 dam over the Southwest, will progress across the srn US and reach the South Atlantic states this weekend. Surface high pressure beneath and downstream of the associated ridge will extend from near Bermuda to the South Atlantic coast, while a trough will extend in the lee of the srn and cntl Appalachians and a sea breeze will move through the entirety of cntl NC each late afternoon-evening. Warm and seasonably moist sswly flow around the Bermuda high and across cntl NC will favor afternoon temperatures in the lwr-mid 90s and mixed dewpoints mostly in the mid-upr 50s by Sun-Mon, with a related weakly unstable and weakly capped environment supportive of isolated convection - favored along the lee trough invof the nw Piedmont.

AVIATION /12Z TUESDAY THROUGH SATURDAY/

As of 630 AM Tuesday...

24 hour TAF period: The dense fog should quickly burn off by 9 AM, with VFR conditions prevailing thereafter. Calm to light nly to nnely winds expected through daybreak, increasing and becoming sly, first at KINT/KGSO this morning and gradually veering to sly elsewhere through the aft/eve.

Outlook: VFR conditions will prevail through Wed, with additional flight restrictions and rain expected with the passage of another frontal system from Wed aft into Thu morn. VFR conditions should return Thu, albeit with gusty winds, and remain VFR through Sat.

RAH WATCHES/WARNINGS/ADVISORIES

Dense Fog Advisory until 9 AM EDT this morning for NCZ007>011- 022>028-039>041-074>076.