Garner, North Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

437
FXUS62 KRAH 251018
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
618 AM EDT Mon May 25 2026

.WHAT HAS CHANGED...

* Isolated heavy rainfall possible today with anomalously high
  moisture

&&

.KEY MESSAGES...
As of 300 AM Monday...

1) Isolated to scattered storms today capable of heavy rainfall,
focused along residual boundaries and small-scale circulations

2) It will be continued warm and unseasonably humid/muggy through
Wed evening, with scattered to locally numerous showers and storms,
then less humid but with a lingering chance of convection on Thu.

3) Another chance of rain/convection early this weekend will
interrupt a probably dry end of this week and early to mid part of
the following one.

&&

.DISCUSSION...
As of 300 AM Monday...

KEY MESSAGE 1... Isolated to scattered storms today capable of
heavy rainfall, focused along residual boundaries and small-
scale circulations

Storm chances today across central NC will have the potential for
heavy rainfall in isolated locations. The deep-layer moisture
approaches 2 inches of precipitable water, roughly 200-percent of
normal for this time of year. A continued southwest flow will
persist today, as central NC is situated northwest of the 591 dm mid-
level ridge. At the surface, general SSW flow will be in place
around the Bermuda high.

Our storm chances today look to be focused and driven by small-scale
boundaries and remnant MCVs. Satellite and radar presently indicate
a remnant MCV tracking across western NC. This along with 925-mb
moisture transport will warrant isolated to scattered showers around
portions of central NC into mid-morning. The aforementioned MCV
should lift into VA this afternoon. The high-res CAMs are then
suggesting an earlier initiation of convection today, perhaps as
early as midday for areas along/east of US-1. This convection
appears to be tied to a remnant MCV currently in central SC that
will reach central/eastern areas of central NC late-morning and
afternoon, as well as a pronounced surface theta-e gradient oriented
along the US-1 corridor. This may force isolated to scattered storms
over the Sandhills, eastern Piedmont, Triangle, and Coastal Plain
into early evening. Another area of convection may develop late in
the day into the late-evening over the Triad and northwest Piedmont
tied to the remnant CAD boundary. While confidence is not great,
there is the potential for isolated heavy rainfall given the highly
anomalous moisture and thus efficient rain rates with any slow-
moving cells. The HREF/REFS both suggest isolated totals of 1-3
inches of rain along the prior mentioned focus regions. WPC has a
marginal risk of excessive rain over all of central NC. Any flood
threat appears minimal except in low-lying or urban areas. Outside
of these heavy rain areas, rainfall totals of a quarter to one half
inch is possible, with some areas seeing less than that.

While most convection should die out by late evening, another MCV
upstream could bring pockets of light showers overnight, but with
much less coverage overall and focused across the north and west
along the residual surface boundary.


KEY MESSAGE 2... It will be continued warm and unseasonably
humid/muggy through Wed evening, with scattered to locally numerous
showers and storms, then less humid but with a lingering chance of
convection on Thu.

Between a sub-tropical high sw of Bermuda and a trough that will
reload over the srn Plains and lwr MS Valley, a plume of PWs around
2" and 150-190% of normal, and MCVs, will be directed from the Gulf
to the Carolinas and srn Middle Atlantic through Wed.

At the surface, a front will waver over nrn NC and VA through Wed
evening, with closest proximity and focus for convection in cntl NC
on Tue and again Wed evening. A convectively/diabatically-reinforced
and modulated theta-e gradient over the Southeast and Carolinas will
also likely remain and serve as a possible focus for additional
convection. A reinforcing, nrn stream cold front will meanwhile
progress across the Great Lakes and Middle Atlantic and then across
cntl NC Thu-Thu evening.

Influence from the forcing features amid the deep moist axis noted
above will favor the development of scattered to locally numerous
convection, with the potential for pockets of heavy rain. It will
otherwise be unseasonably warm and humid, the first combination of
the two of the season, with temperatures warming well into the 80s
and accompanied by surface dewpoints in the upr 60s-lwr 70s F
through Wed, and with associated low temperatures not much lower
than those surface dewpoint values. While it will remain warm and
well into the 80s ahead of the nrn stream cold front on Thu, the
richer low-level moisture and humidity will likely have been swept
swd by the lead front forecast to progress across the forecast area
Wed evening. The nrn stream front may nonetheless trigger widely
scattered showers/storms Thu afternoon-evening.


KEY MESSAGE 3... Another chance of rain/convection early this
weekend will interrupt a probably dry end of this week and early to
mid part of the following one.

The sub-tropical high initially off the South Atlantic coast (sw of
Bermuda) will weaken and retreat into the Caribbean, as a negative
height anomaly and surrounding trough develop across Atlantic
Canada, another progresses slowly into the Great Basin, and a
blocking high develops between the two and across cntl Canada. The
models have come into better agreement with the progression of a
compact cyclone across and offshore the nrn Middle Atlantic and New
England early next weekend, around the negative height anomaly over
Atlantic Canada.

At the surface, weak high pressure and a drier airmass will likely
infiltrate cntl NC Thu night-Fri, ahead of a frontal system that
will accompany the trough in nw flow aloft Fri night-Sat. A stronger
area of high pressure and related dry/continental air will then
probably settle across the MS Valley and much of the ern US through
at least the early to mid part of next week, beneath and downstream
of the aforementioned, persistent blocking high.

The approach of the trough in nw flow aloft may cause the deep moist
axis, which will have been shunted south and swwd of cntl NC late in
the week, to retreat nwd and provide for another chance of
rain/convection along the related surface frontal system early this
weekend, with following dry conditions probable for the early to mid
part of the following week.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
As of 618 AM Monday...

Areas of LIFR/IFR conditions this morning will lift to MVFR by mid
to late morning and eventually improve to VFR this afternoon,
earliest at FAY and latest at GSO/INT. A remnant MCV will bring a
period of SHRA to RDU/FAY this morning, briefly favoring sub-VFR
visibilities. The high-res ensemble guidance of the HREF/REFS have
continued to trend earlier with the initiation of convection today,
with the main timeframe at RDU/FAY/RWI in the 16-21z time frame.
This convection appears associated with an MCV moving in from SC.
Given this trend, we modified TEMPO groups for -TSRA to an earlier
start time, though it is entirely possible convection develops a bit
later than anticipated. The chance of storms at GSO/INT is favored
to be later, in the 22z-02z time frame, tied to a residual surface
boundary. Outside of these time periods, some isolated showers will
be possible overnight with another upstream disturbance, most
favored at GSO/INT. Areas of LIFR/IFR ceilings are expected to
redevelop again into Tue morning.

Outlook: Daily chances for showers and storms will continue through
midweek, along with morning fog or stratus. A trend to drier weather
is favored Thursday and Friday.

&&

.CLIMATE...

Record High Minimum Temperatures:

May 25:
KRDU: 71/2019
KFAY: 71/2019

May 26:
KGSO: 70/2019
KRDU: 73/2011
KFAY: 75/2004

May 27:
KRDU: 72/1991
KFAY: 72/2006

May 28:
KGSO: 70/2012
KRDU: 74/1914

&&

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

&&

$$

DISCUSSION...Kren/MWS
AVIATION...Kren
CLIMATE...RAH