textproduct: Raleigh

WHAT HAS CHANGED

* Risk for excessive rain shifting more toward Saturday.

KEY MESSAGES

As of 1218 PM Wednesday...

1) Extended period of very warm to hot temperatures, with Thursday and Friday expected to be the hottest.

2) Marginal risk for excessive rain (flash flooding) on Saturday.

DISCUSSION

As of 1218 PM Wednesday...

KEY MESSAGE 1... Extended period of very warm to hot temperatures, with Thursday and Friday expected to be the hottest.

Central NC is expected to be in a pattern of above normal temperatures over the next week. This afternoon through Friday, high pressure located off the coast will bring southerly flow and warm, moist air to the region. Highs this afternoon should remain in the upper 80s, rising to the low/mid 90s on Thursday and Friday. With increasing dew points each day, heat indices should be the highest on Friday, potentially reaching the low 100s. A weak cold front looks to dissipate over the region on Saturday. This does not appear to drop temperatures too much, with temperatures Sunday through mid- week remaining in the upper 80s to low 90s.

2) Marginal risk for excessive rain (flash flooding) on Saturday.

The cold front currently across the Great Lakes and Midwest regions will gradually move toward the Carolinas through the week then begin to move across our area on Saturday. While PoPs (showers/tstms) will begin to increase on Friday as the front gets closer, the highest PoPs and thus best chance for shower/tstms with occasional heavy downpours will occur on Saturday, particularly during the afternoon and evening. Day 4 ERO indicates a marginal risk for flash flooding across all of central NC given abundant pre-frontal moisture advection and risk for cell training.

AVIATION /00Z THURSDAY THROUGH MONDAY/

As of 745 PM Wednesday...

Shallow moisture return near and west of FAY may bring the risk for SCT/BKN IFR to LIFR cigs or fog to FAY. Probability of occurrence is and has remained around 25% chance between 10 and 14z, which is too low to include in the 00z TAFs at this time, but may be included in the 06z TAFs. Otherwise, a shallow inversion and strengthening LLJ around 1,000 ft may result in marginal LLWS tonight, strongest at INT/GSO. Lack of meaningful wind direction change and marginal magnitudes of 25 to 35 kts and sustained 5-10 kts at the surface precludes the need to mention LLWS in the 00z TAFs.

Outlook: A cold front will slowly work its way south from VA and potentially into NC Fri into Fri night. This boundary will likely be a focus for convection, but also bring a risk for post-frontal sub- VFR cigs Sat morning. An approaching disturbance from the TN Valley and Deep South will bring a chance for more scattered to widespread showers/storms on Sat that may continue into early overnight period.

RAH WATCHES/WARNINGS/ADVISORIES

None.