textproduct: Raleigh

WHAT HAS CHANGED

* Nothing appreciable

KEY MESSAGES

As of 200 AM Monday...

1) Much of the upcoming workweek will be unseasonably warm and dry.

2) A strong but moisture-starved cold front will cross the region late Friday, bringing a significant cooldown over the weekend with patchy frost not out of the question.

DISCUSSION

As of 200 AM Monday...

KEY MESSAGE 1... Much of the upcoming workweek will be unseasonably warm and dry.

Broad mid/upper ridging over the Southeastern US (in between troughing over the North Atlantic that will absorb the remnants of Isaias and a closed low over the Intermountain West) will bring mostly sunny and dry weather to central NC for much of the upcoming workweek. A weak shortwave and associated surface low will track east from the Great Lakes into northern New England from Tuesday into early Wednesday, dropping a backdoor cold front southward into the Mid-Atlantic. SW flow between the low to the north and high pressure just offshore will bring increasing temperatures to start the week, with highs in the upper-70s to lower-80s on Monday and lower-to-mid-80s on Tuesday. Guidance has continued to trend slower with the backdoor front, and it is now unclear if it even makes it this far south. This results in a very warm forecast from Wednesday through Friday, with highs in the mid-to-upper-80s and lows in the lower-to-mid-60s. Thursday has potential to be a little cooler with some cloud cover in the north, but that will depend on how far south the front is able to get. Any precipitation with the front will be minimal and largely pinned over VA due to the ridge in place.

KEY MESSAGE 2... A strong but moisture-starved cold front will cross the region late Friday, bringing a significant cooldown over the weekend with patchy frost not out of the question.

A much more vigorous northern stream shortwave will dive down from Canada into the northern Plains and Great Lakes region on Thursday and Friday, potentially interacting with the closed low over the Western US and deepening as it shifts into the Northeast US. The ECMWF and GFS have come into better agreement on the timing and overall pattern evolution, dragging a strong cold front through the area late Friday. The best height falls will be well to our north so any associated precipitation would be light, and POPs are only slight chance at best.

A significant cooldown to below-normal temperatures appears likely behind the front over the weekend as Canadian high pressure builds in. Forecast highs on Saturday and Sunday are only in the lower-to- mid-60s, which is about 8-12 degrees below normal. Patchy frost may even be a concern, most likely on Saturday night as this is when low- level thicknesses bottom out. While most places have forecast lows in the upper-30s to lower-40s, isolated mid-30s aren't out of the question in cooler outlying areas according to some MOS guidance.

AVIATION /06Z MONDAY THROUGH FRIDAY/

As of 200 AM Monday...

Deformation band moisture, in cyclonic flow surrounding an area of low pressure now tracking along the Middle Atlantic coast, will result in occasional MVFR to VFR stratocumulus bases today. While most associated ceilings will be VFR, there is a chance of a brief MVFR one at RWI and RDU between 14-17Z, as daytime heating concentrates moisture at the top of the developing mixed/boundary layer. Surface winds will also become gusty from the northwest with daytime heating, into the teens to near 20s kts.

Outlook: Aside from a small chance of patchy visibility restrictions in mist/fog at FAY Wed morning, influence from high pressure over the Southeast will favor mainly VFR conditions over cntl NC for most of the upcoming week.

CLIMATE

Record High Temperatures:

October 13: KRDU: 89/1954

October 14: KGSO: 85/1975 KRDU: 86/1985 KFAY: 90/1954

October 15: KGSO: 87/1985 KRDU: 88/1985

October 16: KGSO: 85/1953 KRDU: 86/1925

Record High Minimum Temperatures:

October 12: KGSO: 64/2017

October 15: KGSO: 63/1985 KRDU: 66/1942

RAH WATCHES/WARNINGS/ADVISORIES

None.