National Weather Service Raw Text Product

193 
FXUS61 KBGM 231750
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
150 PM EDT Mon Jul 23 2018

.SYNOPSIS...
A wet and unsettled weather pattern will persist through mid-
week across the region. A deep southerly flow of very moist air
will reside over the area through Thursday. Showers and 
thunderstorms are expected through the period with the activity 
most widespread during the daylight hours. The thunderstorms 
will produce very heavy downpours.

&&

.NEAR TERM /THROUGH TUESDAY/...
1040 AM update...
Current forecast in good shape with just minor short term
adjustments. So far this morning the heaviest rainfall has
occurred across parts of northeast Pennsylvania and the western
Catskills. Mesoscale models indicate the most widespread
coverage this afternoon will continue in the western Catskills
and also from northeast Pennsylvania into the central southern
tier. By later this afternoon as instability increases showers
and thunderstorms will be likely well into the western Mohawk
Valley. So far streams have shown very little response from
rainfall due to dry antecedent conditions but continued  
convection will lead to saturated soils and possible flash flood
concerns. Will likely issue a flash flood watch this afternoon
for northeast Pennsylvania, the southern tier and western
Catskills, once the 12Z guidance analyzed.

400 AM Update...
Today...Not a lot of change to the current near term forecast 
thinking. A deep south/southeast flow of very moist air will 
continue over the region as an upper level low remains nearly 
stationary over the Tennessee Valley while an upper level ridge 
resides in the western Atlantic. A combination of embedded mid- 
level short waves and diurnal instability will increase 
convective coverage by late morning through the evening hours. 
0-6km shear near 30kts, and low level shear (0-1km) between 
20-30 kts could indicate the potential for a stronger t'storm or
two this afternoon as well...the main threat would be gusty 
outflow winds. Precipitable water values increase to around 
2-2.25 inches by this afternoon and model soundings indicate 
tall/skinny CAPE along with warm cloud layer above 10k feet. 
This all indicates the potential for very heavy downpours with 
any thunderstorms and will include in the forecast from early 
morning through the evening hours. No flood watches planned yet 
but if training convection occurs during the next several days a
watch may be needed...once confidence on exact placement of the
heaviest rainfall becomes more apparent. Highs this afternoon 
will range in the upper 70s to mid 80s and with dewpoints around
68-72 it will feel rather muggy and uncomfortable.

Tonight: The overall weather pattern remains the same, with deep
sub-tropical moisture continuing to stream northward into our
area. There will likely be periods of rain, with embedded
t'storms continuing through the overnight hours. Again, the main
concern would be if these bands of rain end up training over the
same locations for an extended period of time. PWATs remain at
or above 2" and sfc dew points hold in the upper 60s to near 70.
Lows will be near the dew points, mainly 67-73 degrees.

Tuesday: More of the same, as the deep tropical feed of moisture
continues off the Atlantic. Things will likely destabilized once
again in the later morning and afternoon, leading to rather
widespread t'storm coverage. PWATs remain around 2", and the 
main concern will be for more heavy rain. WPC has most of our NE
PA counties under a moderate risk for excessive rainfall during
this period, with a slight risk extending north across all of 
our CNY zones. Highs will be a little cooler with the ample 
cloud cover, showers and storms around...mainly 75-82 degrees. 
Total rainfall amounts through Tuesday look to range from about 
0.50-1.00" across north-central NY, 1-2 inches across the NY 
southern tier, with 1.50-3.00" across our NE PA counties and 
Sullivan County NY. These are area average rainfall 
amounts...and there could certainly be localized heavier 
amounts. These types of rainfall amounts will certainly cause 
rises on area streams and rivers, however at this time, the main
stem rivers are not forecast reach action stage through 
Wednesday morning. We will still need to monitor all area rivers
and streams closely, as localized heavier rainfall could cause 
more significant rises (than currently forecast). The initial 
threat could be more for localized, flashy type flooding of 
urban and/or poor drainage areas...and perhaps small streams. 
Again, will monitor this potential closely and flood watches may
eventually be necessary.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
430 am update... 
Main concern in the short term is focused on the continued threat 
for heavy rain Tuesday night and Wednesday.

The closed upper low over the OH Valley...now an open wave will 
rotate a fairly robust short wave ewd through NY/PA Tuesday night 
and Wednesday which will interact with a deep and very moist air 
mass...PWATs above 2 inches...and trigger additional showers and 
thunderstorms capable of producing heavy rainfall rates. The concern 
for flooding will be elevated with this round of precipitation due 
to the fact that there will likely be very sensitive areas from 
heavy rain that fell earlier in the week. The N-S axis of 
moisture being advected in from the south will slowly slide to 
the east with the advancing s/w...so there will be some 
progression with these storms, but swd back-building cells are 
possible with rainfall rates potentially exceeding flash flood 
guidance. If the sensitive areas become aligned with the strong 
cells during this time, hydro issues will be likely. Flash Flood
watches and warnings will be likely during this period, so be 
sure to monitor the forecast and any statements issued. 

A strong ewd push of the very humid air mass is expected Wed 
night/Thur morning with much drier air arriving and the threat 
for showers and storms diminishing through the day Thursday. 
Weak surface high pressure builds in and combines with minor 
ridging aloft and the onset of the dry air mass to allow for 
only very low chances for precip. The presence of the persistent
cyclonic flow aloft is the main factor in keeping slight chance
of showers and/or storms around during the day Thursday. 

Temperatures Wednesday and Thursday will remain on the warm side 
with highs topping out in the upper 70s and lower 80s...and 
overnight lows in the mid to upper 60s.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
430 am update... 
Conditions should be fairly quiet Thursday night with only a few 
lingering rain showers possible in the srn Catskills and Poconos, 
and potentially a few showers along the leading edge of the next 
upper wave and sfc front expected to track through during the day 
Friday. A quick surge of high moisture content air will advect in 
from the sw ahead of the front on Friday and combine with more than 
1000 J/kg of CAPE and plenty of deep layer shear to produce showers 
and thunderstorms...potentially a few strong to severe storms over 
the ern half of the forecast area later in the day.

More uncertainty arrives this weekend with the pattern definitely 
not as active as earlier in the week, but with timing differences in 
the arrival of the next upper wave. The GFS brings the wave in
from the sw on Sunday, while the ECMWF and CMC wait until 
Monday. Will hold ground and keep slight chance pops through the
weekend.

Temperatures through the end of the week remain mild and near 
average with highs in the upper 70s and lower 80s...and lows in the 
upper 50s and 60s.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
A deep southerly flow of tropical moisture will produce
widespread convection both this afternoon and into this evening
and again Tuesday afternoon. In general, MVFR/IFR showers are
expected at all terminals through late afternoon with occurrence
highest at the KELM/KBGM/KAVP terminals. Thunderstorms are
possible but not included in the TAF due to limited areal
coverage. This evening MVFR showers are still likely at
KELM/KBGM/KAVP. Overnight, ceilings will lower into the
MVFR/Alternate Required category except for KSYR. On Tuesday
more MVFR showers with heavy rain are expected after 15Z.

S/SE winds around 10 knots with gusts around 20 knots this 
afternoon and again Tuesday afternoon. 

Outlook... 

Tuesday night through Thursday...Occasional restrictions 
likely, with periods of showers and thunderstorms.

Thursday night/Friday...Brief restrictions possible in 
scattered showers and thunderstorms.

Saturday...Mainly VFR.

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...Flash Flood Watch through Wednesday evening for PAZ038>040-043-
     044-047-048-072.
NY...Flash Flood Watch through Wednesday evening for NYZ022>025-
     044>046-055>057-062.

&&

$$
SYNOPSIS...MJM
NEAR TERM...MJM/RRM
SHORT TERM...BJT
LONG TERM...BJT
AVIATION...RRM