Saturday, July 21, 2018, 10:50 PM EDT
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Area Forecast Discussion
Valid At
Wed, Dec 31, 7:00pm EST
FXUS61 KCTP 220128
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
928 PM EDT Sat Jul 21 2018

.SYNOPSIS...
A hybrid low/rainstorm tracking north over the Delmarva/Chesapeake
Bay will bring widespread moderate to locally heavy rain across
central PA this evening into tonight. This rain event will mark
the start of a very wet pattern with frequent downpours and 
possible flooding through next week.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
Expanded FFA a bit north and extended until 12z. Pattern 
conducive to some heavy rainfall totals overnight. So far 
heaviest totals have been across southern Adams and York 
Counties /some reports over 2"/ with lighter totals to the 
north. Heaviest rainfall may yet be ahead overnight which could 
lead to some flooding inside the watched area. Refer to WPC MPD 
discussion at 0056Z.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
Combination of nearly stationary upper trough over the Ohio
Valley along with southerly flow and above normal PWAT will 
maintain scattered to numerous shower activity Sunday into 
Sunday night. Model QPF is not impressively high on D2, but 
given previous heavy rainfall some areas may prone to flooding
issues.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
By Monday, upper trough will be filling off to our west. Its
position will remain nearly stationary or even retrograde a
little as strong broad ridge forms over the western U.S. For PA,
long fetch moist southerly low-level flow continues for much of
the week, with upper flow turning more SW/W. Not much to inhibit
daily convection, so the quite unsettled pattern will continue
as plenty of clouds abound.

Best daily chances for tstorms shifts to western/central 
sections early in the week (as ridge briefly edges in from the
east) before precip shifts eastward Thu as a cold frontal 
boundary finally pushes across the state. The weekend looks
drier.

Though it will be quite muggy, temperatures will be at or
slightly below below normal much of the week.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
Precipitation has overspread all airfield sites as of this
evening. Current radar and short term high resolution models
indicate pockets of moderate rain to move from southeast to
northwest over the next 6-8 hours. 

Models indicate a heavy band of rain moving north from KMDT-
KUNV-KBFD from 05Z-09Z. Then a quick transition to light rain
and then dry weather around 12Z.  

By the end of the forecast period, scattered convection will 
develop but just put in VCTS for now as the timing and exact 
location of airfield effects is too far out to be more specific.

.Outlook... 

Mon-Wed...Frequent showers/isolated T'storms with associated 
MVFR/IFR restrictions.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch until 8 AM EDT Sunday for PAZ019-026>028-035-
036-045-046-049>053-056>059-063>066.

&&

$$
SYNOPSIS...Steinbugl
NEAR TERM...Ross/Steinbugl
SHORT TERM...Steinbugl
LONG TERM...RXR
AVIATION...Steinbugl/Tyburski

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