286
FXUS62 KRAH 310602
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
200 AM EDT Fri May 31 2024

.SYNOPSIS...
A vigorous mid and upper-level disturbance will pivot across and
offshore the southern Middle Atlantic through early Friday. Canadian
high pressure will otherwise extend across the region through early
Saturday, then drift off the coast of the Carolinas by Saturday
night.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 200 AM Friday...

A vigorous shortwave disturbance and an associated strengthening 100-
120kt upper jet diving SEWD through the base of the larger scale
mid/upper level trough will move off the southern mid-Atlantic
coast, including the NC coast later this morning. The glancing shot
shot of lift and moisture is resulting in some scattered mid clouds
across central NC. Otherwise, showers will remain well east of the
area.  In it`s wake, strong synoptic scale subsidence and drying
will overspread the area. PWATs will fall into 0.4-0.5", which is in
the lowest 0-1 percentile of the climatological data set.

The weather headlines will be the seasonably cool/below normal
temperatures and ultra comfortable humidity as Canadian high
pressure settles over much of the Eastern Seaboard. Highs ranging
from lower/mid 70s north to upper 70s/near 80 south, as BL dewpoints
lower to 30s and 40s across the area.

Anyone with outdoor plans this evening may want to bring along a
light sweater or jacket as strong radiational cooling within the dry
airmass in place will allow temps to cool quickly into the upper
50s/lower 60s, with overnight temps expected to bottom out in the
mid to upper 40s north to lower 50s elsewhere.


&&

.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
As of 200 AM Friday...

Canadian high pressure centered over the area will slide eastward
and offshore during the afternoon and evening as transitory
shortwave ridging aloft builds over the area. The cP airmass will
begin to recover as southerly return flow develops over the area.
Warmer, but still slightly below normal for the 1st day of
meteorological summer. Highs 80 to 85 with dewpoints/humidity still
quite comfortable for this time of year.

Upper ridge axis moves offshore Saturday night. Modest moisture
advection associated with a shortwave trough moving east into the
Ohio and TN Valleys will lead to an increase in mid and high clouds
Saturday night, especially across western NC. However, conditions
will remain dry. Not as cool. Lows 55 to 60.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
As of 340 PM Thursday...


The following few days look to have potential for diurnally-focused
convection as a series of shortwaves moves over or near our region.
However, they look pretty weak and trying to ascertain their exact
timing this far out is difficult. Furthermore, the prevailing flow
looks fairly weak and zonal, and PW values in the guidance are
pretty close to normal. So only carry slight to low chance POPs each
afternoon and evening from Sunday through Tuesday. Instability could
still be sufficient for a few storms, but not concerned about an
organized severe threat and convection will likely be of the pulse
variety.

A closed mid/upper low will then dive SE from the Northern Plains on
Wednesday and Thursday, dragging a cold front to its south. This
will potentially bring central NC a better chance of showers and
storms as upper forcing with it is much stronger. However, timing
uncertainties remain as the ECMWF hangs it back over the Upper
Midwest significantly longer compared to the GFS, with the CMC
somewhere in between. The ECMWF solution would continue just
isolated convection at best on these days. So only have chance POPs
at this time, highest on Thursday.

After another day of near-normal highs in the lower-to-mid-80s on
Sunday, temperatures should warm to slightly above normal for the
workweek as a Bermuda High sets up and brings us continuous S/SW
flow. The operational GFS tries to bring in a backdoor cold front
with highs only in the 60s and 70s on Wednesday and Thursday, but
this solution is an outlier even compared to its own ensembles, so
not taking it too seriously at this time. Forecast highs from Monday
through Thursday are in the mid-80s to 90 with lows in the mid-to-
upper-60s.

&&

.AVIATION /05Z FRIDAY THROUGH TUESDAY/...
As of 100 AM Friday...

Showers and thunderstorms associated with a vigorous upper level
disturbance moving through the southern mid-Atlantic states,
including NC, will remain east of any TAF sites. Otherwise, there is
high confidence in VFR conditions through the 24-hour TAF period.
With the exception of a few gusts of 12 to 15kts, winds will
generally remain light and from the N-NE.

Outlook: Dry VFR conditions will continue through Saturday. Isolated
to scattered chances of mainly diurnal showers/storms returns Sunday
through the middle of next week.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$
SYNOPSIS...MWS
NEAR TERM...CBL
SHORT TERM...CBL
LONG TERM...Danco
AVIATION...CBL