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000
FXUS61 KRNK 231915
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
315 PM EDT Tue Oct 23 2018

.SYNOPSIS...
A cold front will move southeast across the region to off the East
Coast by Wednesday morning, followed by a large high pressure
system. Low pressure that develops in the northern Gulf of Mexico
late Wednesday will track across Florida Thursday then deepen as it
moves northeast, reaching coastal North Carolina Saturday.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
As of 315 PM EDT Tuesday...

A cold front will drop southeast across the region this evening and
push off the East coast tonight. Cooler air comes in behind the
frontal boundary tonight and the air mass dries out above 850MB.
Some low level moisture may get trapped on the western upslope side
of the central Appalachians tonight.

Gusty northwest winds are possible in the mountains through early
this evening immediately behind a dry cold frontal passage. Winds
could gust 25 to 30 mph before diminishing by late evening. In
general, northwest winds will subside after sunset and become light
northwest overnight.  Low temperatures will range from around 30
degrees in the mountains to around 40 degrees in the piedmont.

A large Canadian high will build into the region Wednesday. High
temperatures Wednesday will vary from the mid 40s in the northwest
mountains to the mid 60s into the piedmont.

Confidence is average for all elements.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
As of 315 PM EDT Tuesday...

A short period of tranquil weather is expected during this time, as
a progressive upper air pattern will be in place.

With a large area of high pressure over the region Wednesday
night/Thursday morning, generally went a couple of degrees below
guidance for lows.

Shortwave ridging Thursday will keep the area free from
precipitation, but a large canopy of high/mid level clouds will
blanket the area from west to east Thursday which will keep temps a
couple of degrees cooler compared to Wednesday.

A strengthening low level southerly jet will quickly advance moisture
into our area from the south late Thursday night, and expect light
precipitation to develop, especially in the south by dawn Friday.
Confidence is low on this timing, as there will be a healthy amount
of low level dry air to overcome initially.  Soundings and SREF
probs suggest some higher elevation locations may see a rain/snow
mix initially when precip begins early Friday.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
As of 315 PM EDT Tuesday...

The long range models all paint a similar idea of deepening a
surface low (thanks to the influence of a deepening negatively
tilted upper trof in the eastern U.S.) that exits the Gulf of Mexico
and quickly lifts northeast along the Atlantic seaboard Friday into
Saturday. This will likely bring rain to much of the region Friday
into early Saturday under a strongly diffluent upper air pattern.
While PWAT values are currently not forecast to be especially high,
ensemble forecast suggest a 30-40% chance of river flooding along
the Dan River. A mention of flooding will be placed in the Hazardous
Weather Outlook.

As a result, bumped up winds and POPs during this period. With a
healthy sfc wedge in place, went below guidance for high temps on
Friday

After this system departs, a dynamic upper level shortwave dives
southeast on the western side of the eastern U.S. upper trof,
helping to amplify this trof, keeping temperatures well below normal
and bringing upslope precipitation through the early portion of next
week. Model ensemble members still show uncertainty with the
magnitude of the upper trof, but confidence is high that below
normal temps will be in place during the latter half of the forecast
period. Forecast soundings hint that a rain/snow mix is possible in
the higher elevations Sunday and Monday mornings.

&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
As of 147 PM EDT Tuesday...

VFR conditions will prevail through the taf period. High clouds
across southern Virginia and the Carolinas will gradually move
south this evening into tonight. A cold front will drop
southeast across the region this afternoon into tonight. Behind
the front, winds will become gusty from the northwest in the
mountains and foothills of Virginia and North Carolina. Wind
gusts up to 25 knots are possible. Winds will slacken after
sunset and become light overnight.

Models have some low level moisture forecast behind the front
along the west slopes of the central Appalachians late tonight.
KLWB has a low chance of having MVFR ceilings after midnight.

VFR conditions are expected Wednesday. Wind will be northwest
around 10 mph.

Confidence is average for TAF elements.

Extended Discussion...

VFR conditions expected through Thursday. The next chance of
rain and sub VFR conditions will be Friday and into the weekend
with a low pressure system crossing the southeast United States
and then moving up the Mid-Atlantic Coast. MVFR showers are
possible in the west early next week.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.

&&

$$
SYNOPSIS...AMS/KK
NEAR TERM...KK
SHORT TERM...PH
LONG TERM...PH
AVIATION...AMS/KK