Scientific Forecaster Discussion
fxus61 kokx 161000
Area forecast discussion
National Weather Service New York New York
600 am EDT sun Jun 16 2019
a weakening cold front will pass through the area late this
afternoon into the evening. The front remains close to the
region through much of the upcoming week. Several waves of low
pressure may move along the front, bringing periods of
Near term /through tonight/...
the forecast is on track this morning. Rain will continue to
track across the region early this morning. Additional showers
across PA will clip northern parts of the area later this
morning, with the remaining area seeing precipitation more
scattered in nature. The modeling has not handled the rain well
over the area. Furthermore, the modeling appears to have the
showers and thunderstorms over southern Ohio too far north.
Confidence in the 00z model data is low because of this. A
blended model approach was used, but in addition to this
probabilities for precipitation were increased manually
southward because of the apparent northern bias in the models.
Thunderstorms will be possible beginning this afternoon and
lasting through the evening as the convective complex over Ohio
comes through. The Storm Prediction Center has the southwestern
portion of the forecast area in a marginal risk. There is a high
risk for rip currents at the ocean beaches today. High
temperatures are expected to be close to normal today for most
of the area, however the northwestern interior may stay too
cloudy and rainy to get temperatures to average. The showers and
thunderstorms associated with the convective complex and
residual wave exit the area late tonight. Confidence is not high
with the timing and placement of the rain. Low temperatures
tonight will range from around 60 in the interior to the mid 60s
in New York City.
Short term /Monday through Monday night/...
a lull in the precipitation is possible during the day on Monday,
before additional showers and thunderstorms potentially develop
Monday evening and night. Confidence is low due to a lack of model
agreement and consistency. The placement of a residual frontal
boundary will determine where the best focus for the rainfall will
be. The 00z consensus is that the front remains over the ocean
during the day, then comes back northward overnight. A model blend
was used for precipitation chances. Temperatures are likely to warm
a few degrees with highs in the mid 70s to lower 80s, and lows
in the 60s. There is a moderate rip current risk for Monday.
Long term /Tuesday through Saturday/...
the main story of the long term continues to surround a nearly
stationary frontal boundary that will bring periods of unsettled
weather. Confidence in the timing, duration, and any impacts from
showers and possible storms still remains low, especially from
Monday night through the end of the week.
The flow around the base of an upper low/trough across southeast
Canada will send several shortwaves/disturbance across the tri-
state, but the timing of these is still not well resolved by the 12z
model guidance. These shortwaves in the flow are likely convectively
induced and are difficult for models to resolve past 48 hours.
Another factor of uncertainty is how much if any of these waves
force the frontal boundary further south causing lower precipitation
The next potential shortwave and frontal wave may occur into
Tuesday. Due to model differences and uncertainty in the
strength, placement, and timing of this feature, have capped
pops at 50 percent on Tuesday. Instability looks weak, but have
included mention of a slight chance of thunder.
Another possible shortwave and frontal wave may occur on Wednesday.
However, the European model (ecmwf) is much flatter and weaker compared to the GFS.
Interestingly, the deterministic models are progging a more well
defined shortwave trough and frontal wave for late Thursday into
potentially Friday. This shortwave could leave behind ridging into
early next weekend. Will continue to show chance pops for mainly
showers during much of this time period due to recent model
performance in this pattern.
Temperatures through the long term will average near to slightly
Aviation /10z Sunday through Thursday/...
a weak cold front approaches today and moves through late this
afternoon into evening.
VFR, except MVFR this aftn at kswf. Chc of a shower for a good
portion of the day, but showers become more likely late
aftn/evening. Chance of a thunderstorm mainly for NYC/NJ/lower Hudson
terminals this afternoon/evening.
SW winds around 10 kt incr to around 15 kt with gusts 20-25 kt
this aftn. Winds shift to SW/west for western terminals including
NYC Metro during the late afternoon/early evening push.
Outlook for 06z Monday through Thursday...
Sun night...mainly VFR.
Mon-Thu...there will be chances for showers and isolated
thunderstorms each day, with the better chances Tue and Wed.
VFR, becoming MVFR Monday night. IFR possible Tue and Wed.
Small Craft Advisory conds today and tonight on the ocean waters, but there may be
occasional gusts up to 25 kt along the South Shore bays this
afternoon. Winds subside tonight but seas will remain elevated on
the ocean with a swell. Sub-Small Craft Advisory conds then follow through the rest
of the forecast period with a frontal boundary stalled near the
waters and a relatively weak pressure gradient. Waves of low
pressure will move along this boundary, but their timing and
placement are uncertain. One of these waves could increase winds on
the waters, but overall, conditions should stay below Small Craft Advisory levels
a frontal boundary approaches today and then stalls over the
region through much of next week. The best chance of rain will
be across the lower Hudson Valley and interior southern CT with
up to a half an inch.
Waves of low pressure moving along a nearly stationary frontal
boundary this week could produce periods of moderate to heavy
downpours. The timing, amounts, and any hydrologic impacts remain
NYC National oceanic and atmospheric administration weather radio station kwo35 (162.55 mhz) remains off
New York...high rip current risk through this evening for nyz075-080-081-
Marine...Small Craft Advisory until midnight EDT tonight for anz355.
Small Craft Advisory until 6 am EDT Monday for anz350-353.