Flash Flood Warning 22, NWS State College, PA

Area Forecast Discussion
National Weather Service State College PA
945 PM EDT Mon Jul 23 2018

.SYNOPSIS...
An extended wet pattern with frequent rounds of rain will
continue to elevate the risk of flooding across parts of
central Pennsylvania and the Susquehanna River Valley through
at least mid-week. Drier air will try to work in late in the
week as the deep slow moving upper trough gradually fills and
moves slowly to the east.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Not much change to the forecast this evening as widespread
heavy, fast moving rain showers traverse the area. Currently
tracking a concentrated heavy area entering York and Adams
Counties from MD. FFA remains in effect for much of the area as
favorable conditions continue for heavy rain. With all the rain,
flooding will continue across the region. Refer to WPC MCD 0527
for further discussion.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
*Multi-day heavy to excessive rain risk continues over parts of
 south central PA

An extensive wet pattern will continue to raise concerns for
flash and small stream flooding through the short term period.
The repeated rounds of showers and storms will also push many of
the smaller rivers/larger creeks in the srn half of the area to
bank full or out of their banks. Base flow is already much
higher than just back on Sat, and FFG values are just an inch or
so in the SC & SE counties. Atmospheric river set-up with deep
layer south-southeast flow will maintain very high (2-2.25") PWs
and support intense rain rates. Much like the last 36-42 hours,
though, the cell motion will be very quick, and it will take
training to make the flooding situation dangerous in any given
location. But, that is getting to be a higher and higher
probability as each day of this moisture feed continues.
Temps/winds/dewpoints, etc. are all persistence values.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
Late Tuesday into Wednesday, filling upper trough off to our
west 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 along this river of high PWAT air over the
region, so very efficient precip producers that could exacerbate
flooding situation after several days of noteworthy rains could
continue to bring potential flooding impacts through much of
the week.

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 yet scattered showers may persist.

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

&&

.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
Short term, high-resolution models indicate the waves of rain
showers and convection will be focused over the eastern half of
the forecast area overnight with minimal or no activity across
the western half. Whether rain falls or not, ceilings and
visibility will dip to IFR intermittently through 24/12Z.

All but impossible to time any wave of convection or SHRA
through the entire 24 hours so the best was done for the short
term with radar. After that, a generic VCSH or VCTS was placed
in with the knowledge that conditions will be similar to the
previous 24 hours. Torrential rain with IFR categories will
cross any particular airfield at any particular time based on
the forcing available at that minute in this oversaturated
atmosphere.

.Outlook...

Tue-Wed...Frequent showers and embedded t'storm with heavy
downpours associated.

Thu-Fri...Scattered showers/t'storms possible.

&&

.HYDROLOGY...
Additional heavy rainfall of 2 to 6 inches over the next 24 to
72 hours (mainly over Central PA and the Susq Valley) will pose
a very serious stream and river flooding threat through
midweek. Taking into account the rainfall that already occurred
over the weekend, minor to moderate small stream and creek
flooding is likely with even some impacts on larger main stem
rivers. Some small streams may approach major flooding.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch through Wednesday evening for PAZ006-012-018-
019-025>028-034>037-041-042-045-046-049>053-056>059-063>066.

&&

SYNOPSIS...Lambert
NEAR TERM...Ross/Lambert
SHORT TERM...Dangelo/Lambert
LONG TERM...Ross/RXR
AVIATION...Tyburski
HYDROLOGY...CR

Hazardous Weather Outlook
National Weather Service State College PA
937 AM EDT Mon Jul 23 2018

PAZ004-005-010-011-017-024-033-241345-
Warren-McKean-Elk-Cameron-Clearfield-Cambria-Somerset-
937 AM EDT Mon Jul 23 2018

This Hazardous Weather Outlook is for central Pennsylvania.

.DAY ONE...Today and Tonight.

Periods of heavy showers and a few thunderstorms could bring between
1 and 2 inches of rain across the region mainly to the east of Route
219. Minor flooding of poor drainage areas in cities and towns, and
flooding of some small streams could result from this locally heavy
rain.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to report significant hazardous weather and
flooding.

PAZ006-012-018-019-025>028-034>037-041-042-045-046-049>053-056>059-
063>066-241345-
Potter-Northern Clinton-Northern Centre-Southern Centre-Blair-
Huntingdon-Mifflin-Juniata-Bedford-Fulton-Franklin-Tioga-
Northern Lycoming-Sullivan-Southern Clinton-Southern Lycoming-Union-
Snyder-Montour-Northumberland-Columbia-Perry-Dauphin-Schuylkill-
Lebanon-Cumberland-Adams-York-Lancaster-
937 AM EDT Mon Jul 23 2018

...FLASH FLOOD WATCH IN EFFECT THROUGH WEDNESDAY EVENING...

This Hazardous Weather Outlook is for central Pennsylvania.

.DAY ONE...Today and Tonight.

Please listen to NOAA Weather Radio or go to
weather.gov/StateCollege on the internet for more
information about the following hazards.

   Flash Flood Watch.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Please listen to NOAA Weather Radio or go to
weather.gov/StateCollege on the internet for more
information about the following hazards.

   Flash Flood Watch.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to report significant hazardous weather and
flooding.

Lambert

Special Weather Statement
National Weather Service State College PA
646 PM EDT MON JUL 23 2018

PAZ006-012-045-232315-
Potter PA-Southern Clinton PA-Northern Clinton PA-
646 PM EDT MON JUL 23 2018

...SPECIAL WEATHER STATEMENT...

At 645 PM EDT, Doppler radar indicated strong thunderstorms along a
line extending from near Blanchard to near Tamarack. Movement was
north at 25 mph.

Very heavy rain is expected.
Winds in excess of 30 mph are possible.

Locations impacted include...
Renovo, South Renovo, Cross Fork, Glen Union, Tamarack, Cherry
Springs State Park, Hyner, Ole Bull State Park and Beech Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with these storms, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

Minor flooding may develop. Do not drive into water covering the
roadway.

Turn around don't drown.

&&

LAT...LON 4148 7760 4144 7760 4140 7756 4137 7754
      4135 7750 4103 7756 4105 7758 4106 7756
      4109 7763 4110 7765 4139 7790 4186 7792
TIME...MOT...LOC 2245Z 199DEG 21KT 4113 7760 4140 7782

BANGHOFF

Special Weather Statement
National Weather Service State College PA
656 PM EDT MON JUL 23 2018

PAZ027-028-050-056-063-240000-
Perry PA-Cumberland PA-Juniata PA-Mifflin PA-Snyder PA-
656 PM EDT MON JUL 23 2018

...SPECIAL WEATHER STATEMENT...

At 655 PM EDT, Doppler radar indicated strong thunderstorms over
Colonel Denning State Park, moving north at 35 mph.

Very heavy rain is expected.
Winds in excess of 30 mph are possible.

Locations impacted include...
Carlisle, Lewistown, Plainfield, Burnham, Milroy, Highland Park,
Newville, Honey Grove, Yeagertown, Mcalisterville, McClure, Spruce
Hill, Beaver Springs, Reedsville, Juniata Terrace, Mexico, East
Waterford, Alfarata, Loysville and Ickesburg.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

Minor flooding may develop. Do not drive into water covering the
roadway.

Turn around don't drown.

&&

LAT...LON 4027 7762 4071 7761 4077 7749 4073 7715
      4002 7727 4000 7736
TIME...MOT...LOC 2255Z 186DEG 29KT 4027 7744

BANGHOFF

Special Weather Statement
National Weather Service State College PA
718 PM EDT MON JUL 23 2018

PAZ006-012-037-041-240015-
Potter PA-Northern Clinton PA-Northern Lycoming PA-Tioga PA-
718 PM EDT MON JUL 23 2018

...SPECIAL WEATHER STATEMENT...

At 718 PM EDT, Doppler radar indicated strong thunderstorms along a
line extending from near Denton Hill State Park to near Cammal.
Movement was north at 30 mph.

Winds in excess of 30 mph are possible.

Locations impacted include...
Elkland, Galeton, Westfield, Gaines, Keeneyville, Leetonia, Harrison
Valley, Leonard Harrison State Park, Cedar Run, Cammal, Slate Run,
Lyman Run State Park, Knoxville, Ulysses and Osceola.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with these storms, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

Minor flooding may develop. Do not drive into water covering the
roadway.

Turn around don't drown.

&&

LAT...LON 4199 7727 4187 7729 4125 7749 4177 7781
      4200 7778 4200 7728
TIME...MOT...LOC 2318Z 189DEG 26KT 4176 7777 4137 7753

BANGHOFF