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fxus61 klwx 070902 cca 
afdlwx

Area forecast discussion...corrected
National Weather Service Baltimore Maryland/Washington District of Columbia
400 am EST Sat Dec 7 2019

Synopsis...
high pressure will build across the region through the weekend.
A strong area of low pressure will then develop over the mid-
Mississippi Valley and track northeastward toward the eastern
Great Lakes early next week, with warm and wet weather
enveloping the region. Cold Canadian high pressure will follow
that system later in the week.

&&

Near term /through tonight/...
high pressure currently located over the Midwest will move east
and will be centered overhead this evening. Light winds and dry
conditions are expected today and into tonight. Cold air
advection, light winds and clear skies will allow for
radiational cooling tonight and temperatures will be in the 20s
over most of our County Warning Area.

&&

Short term /Sunday through Monday night/...
high pressure will be moving offshore on on Sunday which will
cause winds to become southerly. This will allow for warm and
moist air advection while temperatures will climb into the mid
to upper 40s over most of our area.

Clouds will be increasing late on Sunday as a weak wave of low
pressure over the Carolinas moves north into Sunday night. This
will increase the chance of showers over our area, especially
late Sunday night. This wave of low pressure will continue to
move north into our are on Monday while another low pressure
system pushes NE from the arklatex region into the Great Lakes
as it deepens. Aloft, a digging trough will be pushing into the
central Continental U.S. And then east into Monday.

Deep moisture ahead of this system and its associated cold
front, along with lift from a low and upper level jet will
combine to bring rain over our area Monday into Monday night.
Precipitable water values are between half and 1.25 inches during this period.

&&

Long term /Tuesday through Friday/...
cold front will likely be just west of the region early
Tuesday, but will be heading eastward through the day and night,
crossing our region by late Tuesday night. There may be some
dry time before the front arrives, and southerly flow may
elevate temperatures into the 60s, so there is a window of some
relatively good weather possible. Timing this far out remains
highly uncertain.

The front appears to be of an anafront nature, which means that
most precipitation will end up falling behind the boundary in
the cooler air, and some of the rain may linger into early
Wednesday. That having been said, the hints of a change to snow on
the back side are rather meager, so have kept any mention of
snow well northwest of the I-95 corridor on Tuesday night and
Wednesday.

Canadian high pressure will then build across the region for the
remainder of the week, resulting in chilly but dry weather.
Temperatures will be below normal, but not exceptionally so.
Just a reminder that it is meteorological winter.

&&

Aviation /09z Saturday through Wednesday/...
winds have diminished over the terminals and clouds have
dissipated at this time. VFR conditions are expected to continue
through Sunday with high pressure in control. Sub-VFR
conditions possible late Sunday night into Monday night with
rain moving over the terminals associated to a low pressure
system and its cold front.

Sub-VFR conditions will be likely at times Tuesday into Tuesday
night as a cold front crosses the region with rain showers. VFR
conditions likely return behind the system on Wednesday. Winds
may gust 20-30 knots through Tuesday and Wednesday, starting out
more southerly Tuesday but ending up northwesterly by Wednesday.

&&

Marine...
a Small Craft Advisory is in effect through Saturday morning.
Winds will be on the decrease Saturday as high pressures moves
east and builds into our area. Winds will remain below criteria
through Sunday night as high pressure remains in control.
Another small craft may be needed on Monday as gradient tightens
over the waters.

Small craft advisories look possible Tuesday as southerly flow
increases ahead of an approaching cold front. They are likely by
Wednesday as northwest winds pick up behind the front.

&&

Lwx watches/warnings/advisories...
District of Columbia...none.
Maryland...none.
Virginia...none.
WV...none.
Marine...Small Craft Advisory until 6 am EST early this morning for
anz531-532-535-536-538>540.
Small Craft Advisory until noon EST today for anz533-534-537-
541>543.

&&

$$
Synopsis...rcm
near term...imr

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