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000
FXUS61 KAKQ 101929
AFDAKQ

AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
229 PM EST Tue Dec 10 2019

.SYNOPSIS...
Low pressure tracks into eastern Canada today with the trailing cold
front crossing the local area this evening. High pressure returns
Wednesday and Thursday. Low pressure develops along the Gulf Coast
Friday before approaching the area this weekend.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
As of 1040 AM EST Tuesday...

Late morning upper air analysis shows broad upper troughing over
the Plains/Midwest, with ridging well off the SE CONUS coast.
At the surface, strong low pressure was over Quebec, with ~1029
mb high pressure over the nrn Plains. A strong (trailing) cold
front was draped from Quebec SSW to the ern Gulf Coast. Across
our local area, the flow was out of the SW at the surface and
aloft. There are a few pre-frontal showers over north/west
zones, but it is mainly dry elsewhere. Skies are BKN-OVC across
the Piedmont, with partly-mostly cloudy skies over the SE half
of the CWA. It has already warmed to near 70F across SE VA/NE
NC, with 60s from central VA to the Lower MD Ern Shore.
Temperatures are still in the upper 50s across the Piedmont.

As the front approaches the region this aftn...the coverage of
showers will increase (some) from W to E. Have PoPs ramping up
to 60% by the mid-late aftn in most areas (except for far SE
VA/NE NC...where PoPs increase to 30-50% by 21z). Consensus of
near-term/hi-res guidance has the front positioned from central
NC to SE VA by early evening. Not everyone will see rain this
aftn, but QPFs (through 00z) will average 0.10" or less. Highs
range from near 60F near LKU to the upper 70s at ECG. Most
record highs today are safe, except for ECG. See Climate section
below.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
As of 330 AM EST Tuesday...

The cold front pushes east across the area late aftrn/erly eve. Data
continue to show strong 850-700 mb frontogenesis through the night
as the mid-level trough axis remains to our W. Pcpn type becomes
stratiformed in nature with near 100 PoP for a decent soaking of
rain (QPF 1/3 to 1/2 inch).

As the night wears on, thicknesses crash along with a quick temp
drop. With pcpn continuing past 12Z, expect the rain to become mixed
with wet snow across the nrn third of the fa aftr 09Z. Once again,
this to be an event much like the mid Nov wet snow where pcpn
intensity will determine whether the pcpn can change over to all wet
snow long enuf to drop the temp (33-34 degrees) for a light accum to
occur. Believe this to be the case across nwrn most zones where
accumls of arnd one half inch will be noted. Expect a rain/wet snow
mix as far south as a Cumberland-RIC-XSA-SBY line. Little to no
accumls expected thru the Wed morning commute here as sfc/wet bulb
temps remain above 32. All rain across the south with lows in the
upr 30s-lwr 40s.

Decent lift conts Wed morning before quickly shutting off after 18Z
as drier air to the west pushes the pcpn offshore. Kept likely-cat
PoPs thru 15Z with a mix of rain/wet snow across the nrn most zones.
Rain south. Expect the pcpn to go back to a cold rain by late morn
as intensity becomes lighter and temps slowly inch up. Pcpn ends and
pushes offshore after 18Z. Dcrg aftrn clouds across the west. Not
much rise in temps given the clouds and CAA. Highs Wed low-mid 40s.

A 1040 mb high tracks across Ohio Wed nite / PA Thurs to a psn near
BOX by 00Z Fri. Mstly clr Wed nite with a secondary CAA surge noted.
Lows in the 20s to lwr 30s se. Sunny/cold Thurs. Went below guid for
high temps. Highs upr 30s-lwr 40s except mid 40s sern coastal areas.

Models show the high is slower to push east Thurs nite. This in turn
slows the advancing moisture from the dvlpng systm to the south.
Thus, will indicate increasing clouds by kept it dry thru 12Z Fri
(per latest GFS/ECMWF solns). Lows may occur early then level off
or rise a bit as the clouds come in. Lows upr 20s nw-lwr 40s se.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
As of 330 AM EST Tuesday...

The high is slow to depart Fri while a significant srn stream
systm is progged to dvlp along the Gulf Coast states before
lifting ne along the ern seaboard over the weekend. The 00Z GFS
conts to be the faster model in bringing overrunning pcpn across
the wrn zones Fri morning, while the 00Z ECMWF holds off any
pcpn until after 18Z. Given these changes, made some adjustments
to Fri fcst. Mainly to slow the onset of pcpn down by svrl hrs.
This allows temps to rise above 32 in most areas for mainly a
cold rain. However, did keep a few hr prd of fz rain at the onset
(per thicknesses) across Louisa/Fluvanna county. Otw, rain
overspreads the local area Fri. Highs low-mid 40s across the
Piedmont (insitu-wedge) to 55-60 along the coast.

The wet period extends into the weekend with the GFS and ECMWF
in better agreement. The wettest period look to be from late
Friday into early Saturday. Will increase PoPs from the
south/southwest during the day on Friday but the bulk of the
precip is expected to fall Friday night into early Saturday as
low pressure lifts northward across the region with the models
in agreement. Conditions Sunday look mostly dry with some cloud
cover. High temps on Friday range from the low 40s NW, close to
50 degrees for the Richmond metro, and low to mid 50s for areas
east of I-95. Not looking particularly cold behind the weekend
system either, highs in the 50s Saturday and Sunday with lows in
the upper 30s and low 40s.

&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
As of 1245 PM EST Tuesday...

VFR conditions prevail early this aftn across the sern
terminals, while MVFR CIGs have been observed at RIC/SBY. A cold
front is approaching the VA Piedmont as low pressure tracks
eastward across Quebec. Ahead of the front, showers have
developed across central VA/the VA Piedmont. These showers will
impact RIC/SBY off and on through the aftn. As the front crosses
the area from west to east, the showers will approach PHF/ORF
later this aftn. However, pcpn likely holds off at ECG until
late aftn/early evening. While prevailing VSBYs likely remain
VFR, brief MVFR (or even IFR) VSBYs will be possible in these
showers. Showers likely continue through the evening...but there
may be a few breaks in the rain before 02-04z.

The front is expected to move S of the terminals by 03z or so.
After that, more widespread, post-frontal (stratiform) rain is
expected through tonight. Thus, the TAF forecast will reflect
CIGs lowering from MVFR to IFR tonight in addition to RA (VSBYs
mainly between 2-4SM). Gusty SW winds (20-25 kt near the coast)
shift to the W, NW, then N this aftn-tonight. N winds could
gust to ~20 kt later tonight. There is an increasing chc that
pcpn changes over to PL/SN Wed AM before ending at SBY, with a
slightly lesser chc of PL/SN at RIC. Not expecting much in the
way of impacts from wintry pcpn, but introduced a mention of
mixed pcpn in the TAFs for RIC/SBY (mainly from 09-14z Wed).
Pcpn should stay in the form of RA at the sern terminals. Pcpn
ends from W to E from Wed AM-midday (at the latest). IFR CIGs
improve to MVFR Wed AM before rising to VFR/scattering out by
aftn.

OUTLOOK...High pressure builds into the area late Wed-Thurs,
allowing VFR/dry conditions to return. Another area of low
pressure brings rain and degraded flight conditions Friday
through Saturday.

&&

.MARINE...
As of 220 PM EST Tuesday...

Cold front will slowly cross the waters through this evening
shifting winds from WSW to NW. Speeds avgg 10-20 kt prefrontal
then some decrease w/ and shortly behind the front. Low level
CAA kicks in by late this evening...through the overnight and
Wed morning before waning. Due to the CAA...speeds to increase
to 15-25 kt...w/ 30 kt possible(for a brief period) over the
lower Ches Bay and the ocean. Winds diminish Wed afternoon. A
second surge of low level CAA expected Wed night (that does
appear to be a bit weaker than the first one tonight) before sfc
hi pres finally builds over the local waters. That sfc hi pres
drifts off to the NE Thu-Thu night. Lo pres begins to develop
INVOF Gulf of Mexico Fri then tracks NNE near the mid-Atlantic
coast by Sat morning which may result in increased winds and
deteriorating wx conditions over the waters heading into the
weekend.

SCAs will be up for all of the waters except parts of the VA
Rivers (though even those areas may have a brief period of near
SCA conditions - winds gusting to 20 kt). SCAs to come down
during Wed for the Ches Bay...sound and lower James River then
will likely be needed again Wed night/early Thu. For the
ocean...SCAs will be up into Thu morning (N) and through Thu
afternoon (S) as seas will remain aoa 5 ft.

&&

.CLIMATE...
Record highs for 12/10:

 RIC...79 in 2007
 ORF...78 in 2007
 SBY...73 in 1966
 ECG...78 in 2007

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...None.
VA...None.
MARINE...Small Craft Advisory until 1 PM EST Wednesday for ANZ632-634.
     Small Craft Advisory until 4 PM EST Wednesday for ANZ633-650-
     652-654.
     Small Craft Advisory until 10 AM EST Wednesday for ANZ630-631-
     638.
     Small Craft Advisory until 7 PM EST Thursday for ANZ656-658.

&&

$$
SYNOPSIS...MPR
NEAR TERM...ERI/MPR
SHORT TERM...MPR
LONG TERM...MPR/RHR/JAO
AVIATION...ERI
MARINE...ALB
CLIMATE...