PBZ issues Area Forecast Discussion (AFD) at Dec 11, 1:10 AM EST665
FXUS61 KPBZ 110610
AFDPBZ
Area Forecast Discussion
National Weather Service Pittsburgh PA
110 AM EST Wed Dec 11 2024
.SYNOPSIS...
Precipitation chances will remain elevated through late
tonight. Rain will change to snow on Wednesday, with much colder
temperatures expected through Thursday. Seasonable temperatures
and rain chances return for the weekend.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
KEY MESSAGES:
- Rain chances continue overnight with crossing low pressure and
a cold front
- Above average temperatures continue through tonight
-------------------------------------------------------------
Low pressure was currently across Lake Ontario, with a cold
front extending southward through western PA and WV. Expect only
a slow progression eastward with the front overnight, as another
wave of low pressure tracks NNE along it. POPs will increase
again from E-W as the next wave approaches, and as some jet
enhancement occurs late.
Previous discussion...
First round of showers is quickly moving northward through the
region. This area of rain is associated with a shortwave rushing
northeastward in the strong southwest flow aloft. Once this
wave exits this evening, the focus for additional rainfall will
turn to locations mainly south and east of Pittsburgh. Another
shortwave, caught up in the southwest flow aloft will cross the
region late tonight and spread precipitation westward as dawn
approaches.
With deep southwest flow, temperatures will continue to remain
10 to 15 degrees above average.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
KEY MESSAGES:
- Areas of rain continue tonight
- Approaching cold front will increase snow chances late Wed
morning
- Snow bands/snow squall potential increases early Thurs
- Cold wind chills and gusty wind late Wednesday and Thursday
-------------------------------------------------------------------
By early Wednesday morning, most of the region will likely
continue to remain in the warm sector under strong southwest
flow.
Rain may start to transition to snow in eastern Ohio as early
as 7am Wednesday. However, with a warm ground, low snow ratios,
and fast moving drier air, snow amount will likely create very
little impacts within the lower elevations during the Wednesday
morning commute.
Winter weather impacts could increase in the higher terrain
with stronger forcing between 18Z and 00Z Wed if snow ratios
increase above 12:1 and synoptic forcing persists. At the
moment, confidence is not high on the QPF amounts given the
quick transition from rain to snow. Therefore, the snowfall
amounts may be overdone in some areas. However, if cold air
advances quicker than projected, a Winter Weather Advisory may
need to be issued for the ridges of West Virginia for 3 inches
of snow.
Along with snow, strong wind gusts with a tight pressure
gradient may prompt headlines in the ridges of eastern Tucker
(where confidence is medium to high for Advisory criteria).
Gusts from 30-35 mph are likely in the lower elevations, with
gusts 40-50mph across the higher terrain.
There will likely be a quick period of quiet, dry weather with
lingering cold conditions early Thursday morning. However, a
number of Hi-Res guidance ensembles suggest convection snow
showers advancing into eastern Ohio/western PA between 01Z and
06Z Thurs morning. The snow squall parameter under the NAMs
peaks in intensity in portions of the area (mostly south of
I-80) and could prompt 0.5 to 1 inch snowfall rates.
Fortunately, these conditions are expected when the volume of
traffic is expected to be low across the region (12am to 4am).
The threat for convection snow showers will likely decrease
after 7am as the shortwave exits east.
Temperatures are expected to remain nearly steady through the
day, as 850 mb temperatures drop to between -16 and -18 deg C.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
KEY MESSAGES:
- Temperatures return to seasonable levels Friday into Saturday
- Precip chances remain elevated Saturday evening into Sunday
-------------------------------------------------------------------
Confidence is increasing that warm weather returns Friday into
Saturday as ridging buildings over the Ohio River Valley as a
new trough digs over the Great Plains. Afternoon high temps will
range 3 to 5 degrees above average on Saturday.
Along with warm weather, expected precip chances to increase
Saturday afternoon into Saturday evening as the trough ejects
north into the Great Lakes. Precip chances decrease late Sunday
under ridging and incoming dry air.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
Cig restrictions will continue through the morning as a slow
moving front crosses the region...followed by a shortwave this
afternoon moving through a deepening NE CONUS longwave trough.
NBM probs are giving 50% to 80% chance of cigs AOB <1kft through
the morning. IFR vis restrictions look likely after rain changes
over to snow and winds pick up(gusts around 25kts) late morning
through the afternoon as cold advection increases. Both the NBM
and HREF show a >90% chance of IFR vis restrictions late
morning and through the afternoon.
Outlook...Dry air begins filtering in by Thursday and will
bring VFR conditions back to the area as clouds erode.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...None.
OH...None.
WV...None.
&&
$$
SYNOPSIS...Hefferan
NEAR TERM...WM/Hefferan/22
SHORT TERM...Hefferan
LONG TERM...Hefferan
AVIATION...88
Source:
PBZ issues Area Forecast Discussion (AFD) at Dec 11, 1:10 AM EST---------------
If I'm using your data in a way that is against your terms please email the team at "threatweb@pupswoof117.com"! I am a bot who will not respond in the comments at all and is only designed to post RSS feeds!
