textproduct: Raleigh

WHAT HAS CHANGED

As of 145 AM Tuesday...

* Minimal changes were made to the forecast for the upcoming week and into early next week. Warm temperatures expected through Saturday, then cooling down early next week. Multiple rounds of rain Thursday night through Sunday night.

KEY MESSAGES

As of 145 AM Tuesday...

1) Patchy dense fog possible this morning.

2) Above-average temperatures are expected Tuesday through Saturday becoming below normal early next week.

3) Potentially unsettled weekend with several rain chances, though confidence in the details remains unclear. Temperatures to trend cooler into early next week

DISCUSSION

As of 145 AM Tuesday...

KEY MESSAGE 1...Patchy dense fog possible this morning.

The center of the high was observed over the mouth of the Chesapeake Bay this morning. A solid shield of stratus is currently blanketing the coast while central NC remains largely clear (although upstream high clouds are spilling in from the west a bit). After assessing latest guidance, think the best chances for any dense fog will be largely across the Coastal Plain over the next few hours. Patchy fog will be possible elsewhere. Any lingering fog should largely lift/dissipate by ~14Z this morning.

KEY MESSAGE 2...Above-average temperatures are expected Tuesday through Saturday becoming below normal early next week.

Surface high pressure over the Mid-Atlantic today will gradually shift offshore by Wednesday morning. In response, southerly flow will strengthen ahead of an approaching warm front, which is expected to lift north through the region on Thursday. This will support a notable warming trend, with afternoon highs reaching the upper 60s to mid 70s. Temperatures on Friday will depend on the timing of an approaching cold front, but current indications suggest it will be the warmest day of the forecast period, with highs ranging from the upper 60s to upper 70s. The cold front is forecast to move through the area late Friday, ushering in a cooler airmass. Behind the front, temperatures will trend below climatological normals, with highs Monday and Tuesday generally in the mid 40s to low 50s. Lows Sunday night will begin a below freezing trend with lows in the low 30s Sunday night, and in the mid/upper 20s to near 30 degrees Mon/Tue nights.

KEY MESSAGE 3...Potentially unsettled weekend with several rain chances, though confidence in the details remains unclear.

A potentially unsettled pattern could evolve from Fri into the weekend as a series of shortwaves move through the region. A surface warm front is likely to move through the region Thu night to early Fri as an occluding surface low tracks into the Great Lakes. This same surface low may bring a cold front into the region Fri night or Sat morning. Showers look to be favored ahead of the cold front Fri aftn/eve. SPC highlights the potential for severe weather Thu to our west in the MS/OH valley region. We remain quite moist on Fri ahead of the front with possible low 60s dewpoints in the south, but overall severe confidence is low as the system occludes.

Over the weekend Sat and Sun, ensemble spread greatly increases, lowering overall confidence in the pattern. The cold front Fri night may stall out or settle along/south of us over the weekend. Ensemble clusters are split on either a trough/ridge pattern, dry versus wet, complicating the overall outcome. Regardless, there does appear to be better agreement for a wetter pattern Sun into early Mon as ensembles show better agreement with potentially a wave of low pressure tracking along the stalled front. Interestingly, the machine learning models show this as well, including the EC-AIFS and AI-GFS, with a more developed and deep shortwave tracking through Sun and Sun night. Overall, confidence in the details are unclear, but it could be wet the latter part of the weekend.

AVIATION /06Z TUESDAY THROUGH SATURDAY/

As of 1258 AM Monday...

06Z update: Still mostly seeing VFR and clear skies out there early this morning. Still expecting a combo of radiation fog and ceilings to develop here in the next several hours, with best dense fog potential still favored at KFAY/KRWI. Otherwise, will hold off on adding sub-VFR ceilings and possibly LLWS for later tonight/early Wednesday morning till the next TAF issuance.

Previous discussion:

A combination of clear and calm tonight, and also residual low-level and soil moisture, should favor the development of radiation fog and ceilings overnight-Tue morning. Based on afternoon crossover temperatures and forecasted winds just above the surface (925mb), RWI and FAY will be the most favorable for fog, potentially dense. Despite favorable soil moisture at the Triad terminals, crossover temperatures will likely not be met, but a period of low clouds may briefly develop as mixing begins after sunrise. RDU will be on the edge of the favorable overlap between soil moisture, light/calm winds, and weaker flow just above the surface, so confidence is lowest here given the high variability between flight categories; opted to largely keep the inherited forecast. VFR will return to all terminals through the morning hours.

Outlook: A good chance of areas of fog and stratus will result again Wed morning, with MVFR ceilings from the latter that may linger through early afternoon. After a risk of low-level wind shear Tue night-Wed morning, swly surface winds will strengthen and become gusty through the day Wed, particularly in areas where clearing and deeper mixing materialize.

RAH WATCHES/WARNINGS/ADVISORIES

None.