575
FXUS62 KRAH 191746
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
146 PM EDT Wed Jun 19 2024

.SYNOPSIS...
High pressure will remain over the Mid Atlantic and Carolinas
through much of this week. Moisture will increase across the area
late this week into this weekend, bringing some increased rain
chances to the Sandhills/Southern Coastal Plain.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 1100 AM Wednesday...

An anomalously strong 598 dam anticyclone at 500 mb will remain
centered over the northern Mid-Atlantic today. At the surface, ~1030
mb high pressure is centered over the western Atlantic to the SE of
New England. This pattern will continue to support easterly flow
both aloft and at the surface through tonight. Visible satellite
shows scattered cumulus already developing, but it will remain
capped beneath a strong subsidence inversion around 800-850 mb.
Water vapor imagery depicts a lot of dry air over central NC, and
this will also continue through tonight with PW values only 70-80%
of normal. This will help dew points again mix out to the upper-50s
to lower-60s in the afternoon. So heat indices will again be close
to the actual air temperatures, which are expected to again reach
the upper-80s to lower-90s with similar low-level thicknesses to
yesterday. Some CAMS depict a few light showers in far eastern NC
this afternoon, but with so much dry air anything should dissipate
before getting this far inland. Lows tonight will again be in the
mid-to-upper-60s.

&&

.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
As of 313 AM Wednesday...

The anomalous mid-level ridge will de-amplify a bit Thursday as the
center of the anticyclone retrogrades over the southeast. The sfc
high will remain anchored offshore, positioned to continue light
esely flow and a steady stream of drier air across central NC (PWAT
remains ~70 to 80 % below normal Thursday). As such, max temps will
remain near 90 and heat indices will remain under criteria as dew
points once again mix out into the lower 60s. Void of lifting
mechanism and moisture, expect another dry weather day on Thursday.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
As of 340 AM Wednesday...

..Dangerously Hot Temperatures Expected this Weekend and into Early
Next Week...

The anomalously strong upper level anticyclone will shift westward
while undergoing gradual weakening through the weekend, before
finally giving way to a northern stream trough that will traverse
the NE US and southern Canada late Sunday and into early next week.
Downstairs at the surface, SELY flow around Bermuda high pressure
will lead to increasing humidity through the weekended, with the
high moving farther out into the Atlantic as a cold front approaches
from the west late in the weekend and into early next week.

The main weather headlines will be in the intensifying heat and
humidity over the weekend and continuing into early next week. Low-
level thicknesses and humidity will steadily rise as the low-level
flow becomes increasingly southerly. By Sunday, highs are forecast
to reach the mid/upper with lower to mid 70 dewpoints becoming more
prevalent across central NC. This combination will support heat
indices of 100-105 F, with Sunday and Monday expected to pose the
greatest heat risk. This level of heat will affect anyone without
effective cooling and/or adequate hydration.

In terms of rain chances, any rain associated with the inverted sfc
trough tracking westward and onshore over FL/GA on Fri will remain
south of the area. Aside from some isolated seabreeze showers/storms
across the far SE zones Friday and Saturday afternoons, mostly dry
conditions will persist through Saturday. Rain chances should begin
to increase Sunday and especially Monday with the approach of the
northern stream trough and attendant front from the NW, that will
have the potential to stall or wash out across the area.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
As of 145 PM Wednesday...

VFR conditions and dry weather will prevail across central NC
through the next 24 hours, with just some scattered cumulus this
afternoon. The one possible exception is parts of the NE Piedmont
and northern Coastal Plain, which 12z HREF probabilities indicate
have a small chance for some fog/mist late tonight and early
tomorrow morning. Considering it did occur at a few spots this
morning, opted to add a TEMPO group for MVFR visibilities at RWI.
Winds will remain easterly and light through the period, around 7
kts or less.

Outlook: VFR and dry conditions should persist through Saturday.
Moisture and the chance for showers will return Sunday and Monday,
especially near KFAY/KRDU/KRWI, which may result in periods of sub-
VFR conditions.

&&

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

&&

$$

SYNOPSIS...Leins
NEAR TERM...Danco
SHORT TERM...Luchetti
LONG TERM...CBL
AVIATION...Danco/Luchetti