416
FXUS62 KRAH 191918
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
318 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 318 PM Wednesday...

An anomalously strong ~598 dam anticyclone at 500 mb will remain
centered over the northern Mid-Atlantic through tonight. At the
surface, ~1030 mb high pressure centered to the SE of New England
will slowly drift south and extend SW into the Mid-Atlantic. This
pattern will continue to support easterly flow both aloft and at the
surface. A pretty extensive deck of scattered to broken flat cumulus
has developed across central NC, 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
is again helping dew points mix out to the upper-50s to lower-60s
this afternoon, which is keeping heat indices well below advisory
criteria and close to the actual air temperatures (mid-80s to 90). A
few light sprinkles off the coast may reach far eastern NC through
early evening, but with so much dry air and subsidence not expecting
anything to make it this far inland. Went on the cooler side with
low temperatures tonight, mostly lower-to-mid-60s, given what
occurred this morning, the dry air in place, and models showing low-
level thicknesses staying very similar.

&&

.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 318 PM Wednesday...

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

Heat will continue to be the primary weather story as we head into
the weekend, thanks to the mid/upr ridge and it anomalously hot
airmass that is currently blanketing areas to our north. That ridge
and it`s airmass will shift south and by Friday will be centered
over the TN Vally, with its airmass extending across our area thanks
to mid/upr northerly flow on the east side of the ridge.  It`s worth
noting an upper trough off of Carolina coast, which will reinforce
the mid/upr northernly flow and aforementioned airmass.  Meanwhile,
the sfc trough that NHC is currently keeping an eye on that is
currently east of the Bahamas is expected to be inland, well to our
south, by Friday morning with no impact on our weather.  The
expansive sfc ridge that`s currently centered just off the Mid-
Atlantic Coast will weaken a bit and drift south by Friday, thus
resulting in low level flow over our area taking on a more s/sw
direction, which will in-turn begin to increase low level moisture
advection across our area for the weekend and into next week (thus
further increasing humidity).

The end result of this pattern will be hot and mostly rain-free
conditions for central NC Friday and this weekend, with intensifying
heat and humidity resulting in highs reaching the mid/upper 90s by
Saturday and perhaps continuing into early next week.  With dew
points in the 70s by then, heat indices of 100-105 F will be
possible 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.

By late Sunday and Monday we`ll finally have PoPs in the forecast,
perhaps in the 20-30 percent range, thanks to increasing moisture in
advance of a short wave trough that will approach late Sunday and
cross our region on Monday.  Hopefully scattered showers/tstms late
Sunday and Monday may provide at least some temporary relief to the
heat. Thereafter, continued hot with below-climo PoPs Tuesday and
Wednesday in the wake of the aforementioned short wave trough.

&&

.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...np
AVIATION...Danco/Luchetti