Area forecast discussion
National Weather Service Raleigh NC
255 PM EDT Sat may 25 2013
Synopsis...
Canadian high pressure will extend across our region through the
Holiday weekend.
&&
Near term /tonight through Sunday night/...
as of 250 PM Saturday...
Tonight: a weak surface trough over central NC will shift southeast off the
Carolina coast around 06z tonight possibly keeping the winds up just
a bit during the evening hours...which may initially slow otherwise
good radiational cooling. Model consensus continues to indicate
increasing cloudiness overnight...mainly across the southwest half
of the area. The Canadian...on the other hand...seems to be handling
the current cloud cover to the north and west the best...albeit a
little slow. Leaning more toward the Canadian...will keep mainly
clear skies...and best radiational cooling...across the northeast
overnight...with gradually increasing clouds over the southwest
between 00z and 12z Sunday. With this in mind...expect overnight
lows in the middle 40s NE to upper 40s SW.
Sunday and Sunday night: the upper low will continue to move off to
the northeast...with a weakening of the pressure gradient and thus
less breezy conditions for Sunday. Northwest flow aloft advecting
dry air into central NC should yield mainly sunny skies...with the
potential for some middle clouds moving in Sunday night. Expect temperatures a
few degrees warmer than today...highs in the middle to upper 70s and
overnight lows in the low to middle 50s.
&&
Short term /Monday and Monday night/...
as of 255 PM Saturday...
Monday and Monday night...
an amplifying middle-upper ridge extending from the lower MS valley
into the Great Lakes coupled with a deep upper low lifting northeastward over
the Canadian Maritimes will maintain a northwest flow aloft over central NC
Monday-Monday night. Perturbations rounding the top of the ridge
will move southeastward and cross our area Monday into early Tuesday. At the
surface...an area of high pressure will be anchored offshore. The
circulation around this system will result in a southerly flow and
associated moisture advection over central NC. The combination of
the increasingly low level moisture and perturbations crossing
overhead are timed with maximum heating may be enough to trigger
isolated convection Monday afternoon-Monday night. Confidence rather
low so will have probability of precipitation no higher than slight across the south half
Monday afternoon...and mainly north half Monday night.
&&
Long term /Tuesday through Saturday/...
as of 255 PM Saturday...
Tuesday through Saturday...mid-upper level ridge builds northward across
the southeast U.S. Initiating a warming trend that will send afternoon
temperatures well into the 80s to near 90 Thursday and Friday. 700mb anti-cyclone
slowly drifts northward with time so that by Friday...wind flow through the
lowest 10k feet S-se. This will aid to abate the heat. Plan to start
out high temperatures in the low-middle 80s Tuesday...warming into the
middle-upper 80s Thursday-Saturday. Min temperatures will also undergo a
gradual warming with min temperatures in the low-middle 60s Wednesday night through
Friday night.
&&
.Aviation /18z Saturday through Thursday/...
As of 134 PM Saturday...
24 hour taf period: very high confidence that VFR conditions will
persist through the taf period as high pressure builds into the
area. Aside from a few high clouds possible...skies should remain
mostly sunny/clear this aft/eve. Increasing middle-high clouds are
expected through the overnight hours...with bases mainly 8-10 kft.
Winds mainly out of the west-northwest have already started to gust
to around 15 kts across the area...with gusts of 15-18 kts expected
between 18z and 00z.
Looking ahead: with high pressure overhead for the next few days...
expect VFR conditions to continue through Memorial Day. As high
pressure shifts offshore on Monday will start to see return flow off
the Atlantic. With increasing low-level moisture early Tuesday and
Wednesday morning the models continue to indicate sub-VFR fog/low
stratus developing...with ceilings lifting to VFR after sunrise.
&&
Climate...
low temperatures on the 26th are expected to fall several degrees
shy of the following records for the date:
Record min temperature/year set may 26th
Rdu 43 / 1979
Gso 42 / 1930
Fay 44 / 1988
Rah watches/warnings/advisories...
none.
&&
$$
Synopsis...mws
near term...kc
short term...wss
long term...wss
aviation...kc
climate...rah
