Area Forecast Discussion
Issued by NWS Sterling, VA
FXUS61 KLWX 291423
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
1023 AM EDT SUN MAY 29 2016
Tropical Depression Bonnie will linger along the Carolina coast
line through the first part of this week while an upper level
trough will track north of the area through Monday. High pressure
briefly builds in before a surface boundary impacts the region
Tuesday. High pressure returns for the second half of the week
with a cold front moving through late in the week.
.NEAR TERM /THROUGH TONIGHT/...
Bonnie has made landfall and been downgraded to a Tropical
Depression this morning. Please refer to the NHC for official
forecasts. Moisture streaming north from the tropical system, with
radar showing the rain has pushed into Southern Virginia. Upper
lvl trough noted on water vapor imagery over the western Great
Lakes region, which will aid in the moisture advection from the
tropical system up across the Mid-Atlantic as it approaches from
the west and helps produce a narrow conduit for the moisture in
combination with the ridge sitting just to the east of us. As
such, still anticipating more widespread rains to move in late
this afternoon and into tonight, with latest hi-res model runs
showing the best chance for moderate to periods of heavy rain
coming this evening and early overnight mainly east of the Blue
Ridge. While 1-2 inches of rain is expected, thinking that it
will mostly occur over a temporal period that will keep flash
flooding threats to a minimum. The main flooding concerns will be
the typical urban, low lying areas.
Rain most likely to continue though the night east of I-95
corridor, with drying from the southwest corner of the CWA to the
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
An upper level trough presently over MN will be tracking east
tonight...moving across ME and into Atlantic Canada Monday. This
will force the moisture from Bonnie more onto the Delmarva...
leaving the highest POPs along the Bay Monday morning. Some
clearing will be possible west of the Blue Ridge during the
afternoon...but much of the area will experience a cloudy Memorial
Day. Highs around 80.
Bonnie will likely be weakening Monday night and Tuesday...
although the eastern part of the area may still be partly to
mostly cloudy Monday night. Mostly sunny across the region
Tuesday. Highs in the mid 80s then lower to mid 60s Tuesday night.
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Weather for the second half of the work week depends on the location
of Bonnie (or her remnants). She is expected to crawl along the
Carolina coast into or perhaps through Thursday. Upper-level ridging
over the eastern Great Lakes should allow an onshore flow and
promote scattered diurnal convective thunderstorms Wednesday.
An upper level trough pushes east across the great lakes Thursday.
The associated cold front enter the LWX CWA Thursday night. This
front looks to stall and both allow continued onshore flow and bring
an active weather period into next week. Temperatures at or just
below normal through the extended.
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
VFR conditions initially today with increasing clouds. As the
rain moves in late this afternoon, should see diminishing cigs and
vis. HOlding at MVFR for now during the periods of heaviest rain,
mainly evening/overnight, but cannot rule out periods of IFR
tonight. Isolated thunderstorms possible during the evening hours.
Winds 10 knots or less. Conditions improve back to VFR on Monday.
Onshore flow Wednesday with diurnal scattered thunderstorms. Cold
front approaches from the west Thursday with continued onshore flow
and possible low ceilings. Cold front stalls over the area into next
Winds expected to remain below SCA values today through Memorial
Day but rain will be moving into the region this afternoon...possibly
heavy tonight and Monday. No problems on the waters Monday Night
Onshore flow likely below SCA levels Wednesday and Thursday ahead of
a cold front and as Bonnie lingers along the NC coast. Thunderstorms
possible in this time.