Special Weather Statement, NWS State College, PA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
136 AM EDT TUE JUL 14 2015

.SYNOPSIS...
A SLOW MOVING UPPER TROUGH AND SURFACE WARM FRONT OVER THE AREA
WILL BRING INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS
TONIGHT INTO TUESDAY NIGHT. HIGH PRESSURE BUILDING SOUTHEAST FROM
THE GREAT LAKES WILL BRING A DRIER WEATHER PATTERN DURING THE
SECOND HALF OF THE WEEK BEFORE INCREASING HEAT AND HUMIDITY RETURN
FOR NEXT WEEKEND...ALONG WITH DAILY CHANCES FOR SHOWERS AND
THUNDERSTORMS.

&&

.NEAR TERM /UNTIL 8 AM THIS MORNING/...
THE EARLIER...NEARLY SOLID LINE OF LIGHT TO MODERATE SHOWERS
/WITH SEVERAL EMBEDDED THUNDERSTORMS/...HAS CONSOLIDATED INTO 2 OR
3 CLUSTERS OF CONVECTION /ONE ENTERING WARREN COUNTY...AND THE
SECOND/LARGER AREA OF SHRA/TSRA PUSHING INTO THE LAUREL HIGHLANDS/.
BOTH AREAS WERE ASSOCIATED WITH COMPACT/MID LEVEL VORT MAXES.
THESE POCKETS OF ENERGY /ABOVE A SLOWLY NEWD ADVANCING WARM
FRONT/ WILL LIKELY DRIFT ENE ACROSS THE CWA OVERNIGHT...TRIGGERING
ADDITIONAL SCATTERED SHRA/ISOLATED TSRA.

THE PAST SEVERAL RUNS OF THE HRRR CONTINUE TO SHOW AN OVERALL
DECREASING TREND IN COVERAGE OF THE PRECIP. HOWEVER...AS PWATS
INCREASE BY ANOTHER 0.25 TO 0.50 INCH OVERNIGHT /TO BETWEEN
1.5-1.75 INCHES/...SCATTERED MODERATE TO BRIEFLY HEAVY SHOWERS
AND A FEW RUMBLES OF THUNDER WILL DRIFT ACROSS THE CENTRAL MTNS
THROUGH ABOUT 07Z...BEFORE REACHING THE MIDDLE SUSQ VALLEY AFTER
08Z TUESDAY.

A MUCH MILDER AND MORE HUMID NIGHT IS IN STORE FOR THE REGION AS
PLENTY OF MID LEVEL CLOUDS LINGER...AND SFC DEWPOINTS IN THE
LOWER-MID 60S REMAIN STEADY...OR SLOWLY CREEP UP LATE TONIGHT.

LOW TEMPS EARLY TUESDAY WILL VARY FROM NEAR 60F IN THE COLDEST
RURAL VALLEYS UP NORTH...TO ABOUT 66 OR 67F IN THE METRO AREAS
THROUGHOUT THE LOWER SUSQ VALLEY.

&&

.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
TUESDAY SHOULD BE THE MOST ACTIVE DAY OF THE WEEK AS THE UPPER
TROUGH DROPPING OUT OF THE GR LAKES BRINGS A LOW AND SOMEWHAT
COMPLICATED FRONTAL SYSTEM INTO THE REGION. WARM FRONT WILL BE
SPLITTING THE STATE NW/SE EARLY...WITH A COLD FRONT/OCCLUSION
PUSHING INTO THE STATE DURING THE DAY /WITH MODELS INDICATING
THAT SOME SORT OF SECONDARY LOW WILL TRY TO FORM NEAR THE
DELMARVA PENINSULA BY LATE DAY/.

PRECIP SHOULD BE ONGOING TO START THE PERIOD ACROSS THE WEST. AS
THE UPPER TROUGH DEEPENS OVERHEAD...GUIDANCE SHOWS STEEPENING MID
LEVEL LAPSE RATES WITH CAPES IN EXCESS OF 1000J BY AFTERNOON. WIND
FIELDS WILL NOT BE TERRIBLY IMPRESSIVE WHICH WILL MINIMIZE THE
THREAT OF SEVERE STORMS...BUT WITH PWATS QUICKLY SURGING UP OVER
1.5"...SLOWER MOVING CONVECTION COULD PRESENT LOCALIZED FLOODING
PROBLEMS. WPC HAS THE SOUTHERN HALF OF THE FCST AREA IN A SLIGHT
RISK FOR EXCESSIVE RAINS WITH BASIN AVERAGE AMOUNTS OF .50" TO
1.00" POSSIBLE. DON/T PLAN ANY FLOOD WATCHES AT THIS TIME...JUST
HIGHLIGHTING THE POTENTIAL IN OUR DISCUSSIONS AND MENTIONED SOME
TSTMS MAY CONTAIN HEAVY RAINFALL IN THE GRIDS/ZONES.

PLENTY OF CLOUDS AND INCREASING PRECIP COVERAGE WILL KEEP DAYTIME
HIGHS SLIGHTLY BELOW MID JULY NORMALS IN NW HALF. HIGHS LOOK TO
PEAK IN THE LWR/MID 80S IN THE SE.

MAIN COLD FRONT GRADUALLY WORKS ACROSS CWA FROM GREAT LAKES TUE
NIGHT...BUT WEAK LOW ALONG INITIAL COLD FRONT/OCCLUSION WILL SLIDE
FROM THE MID ATLANTIC STATES TO NEW ENGLAND KEEPING MENTION OF
SHOWERS IN THE SE THROUGH THE NIGHT. DRIER AIR WILL SLIDE IN
BEHIND THE FRONT...WITH A LOWS DROPPING TO AROUND 60 IN THE NORTH.
WHILE MUGGY CONDITIONS PERSIST IN THE SE WITH LOWS HANGING NEAR
70F.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THE ANOMALOUS MID-LEVEL TROUGH AND ASSOCIATED "DEEP" SFC LOW ALONG
THE NRN MID ATLANTIC COAST AT THE START OF THE PERIOD WILL SHIFT
OFFSHORE BY 00Z THU. HIGH PRESSURE INITIALLY CENTERED OVER NWRN
ONTARIO WILL MIGRATE EWD THRU QUEBEC/NRN NEW ENGLAND INTO THE NRN
ATLANTIC BY SATURDAY. 500MB HEIGHTS SHOULD STEADILY REBOUND THROUGH
THE WEEKEND WITH VERY WARM AND HUMID CONDITIONS FORECAST. CENTRAL PA
IS CURRENTLY NEAR/AT THE CLIMATOLOGICAL HOTTEST TIME OF THE YEAR
/JULY 11-20/.

SHOWERS SHOULD EXIT SOUTHERN/EASTERN AREAS EARLY WEDNESDAY. A LARGE
AREA OF BELOW NORMAL PW AIR WILL OVERSPREAD THE NORTHEAST AND MID
ATLANTIC STATES WED NGT THROUGH THURSDAY WHICH WILL ENSURE DRY WX
DURING THIS TIME. MUCH OF FRIDAY ALSO LOOKS DRY WITH A VERY LOW
RISK (20% OR LESS) OF A LATE DAY SHOWER/TSTM ACROSS THE FAR WRN
ALLEGHENIES. WED/THU NIGHTS WILL BE REFRESHINGLY COOL WITH A FEW
SPOTS IN THE NRN TIER LKLY DROPPING INTO THE MID/UPPER 40S.

THE UPSTREAM FLOW ALOFT IS FCST TO BE MAINLY ZONAL ON THE NRN
PERIPHERY OF SRN PLAINS RIDGE...FROM THE MIDWEST THROUGH THE
GREAT LAKES WITH WEAK TROUGHING LKLY ALONG OR OFFSHORE THE
EASTERN SEABOARD. NRN STREAM S/WVS MOVING INTO THE AREA FROM THE
WNW MAY BE A FOCUS FOR SHOWERS/TSTMS. THE SFC PATTERN LOOKS VERY
DIFFUSE OVER THE WEEKEND WITH MODEL DATA SUGGESTING POTENTIAL FOR
MAINLY AFTERNOON CONVECTION.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
A WEAKENING UPPER LEVEL DISTURBANCE WILL PUSH THROUGH CENTRAL PA
OVERNIGHT...ACCOMPANIED BY A DWINDLING LINE OF SHRA/TSRA. AN AREA
OF SHOWERS IN NORTHERN MARYLAND IS MOVING NORTHEAST AND WILL
LIKELY AFFECT THE KMDT AND KLNS 10-12Z. SHOWERS JUST TO THE NORTH
OF KBFD WILL ALSO MOVE NORTHEAST.

OVERNIGHT...THE MAIN AVIATION CONCERN WILL BE THE POTENTIAL OF
LOW CIGS RESULTING FROM MOIST SOUTH-SERLY FLOW ASCENDING THE
HIGHER TERRAIN OF CENTRAL PA. SOUTHERLY FLOW CLIMATOLOGY SUGGESTS
KBFD IS MOST LIKELY TO EXPERIENCE IFR CONDS. HOWEVER...CAN/T RULE
OUT BRIEF IFR CONDS OVR MOST OTHER CENTRAL PA AIRFIELDS...MAINLY
BTWN 06Z-12Z.

EXPECT ANY LOW CIGS TO LIFT BY LATE AM...AS A WARM FRONT LIFTS NE
THRU THE REGION. WIDESPREAD VFR CONDS EXPECTED TUE AFTN.
HOWEVER...SCT TSRA ARE LIKELY TO DEVELOP DURING THE PM
HOURS...PRODUCING BRIEF VIS REDUCTIONS IN SPOTS.

OUTLOOK...

WED...EARLY AM LOW CIGS LIKELY ACROSS THE W MTNS.

THU-FRI...NO SIG WX EXPECTED.

SAT...SCT PM TSRA IMPACTS POSSIBLE.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

SYNOPSIS...LAMBERT/RXR
NEAR TERM...LAMBERT
SHORT TERM...RXR
LONG TERM...STEINBUGL
AVIATION...FITZGERALD/TYBURSKI

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE STATE COLLEGE PA
317 AM EDT TUE JUL 14 2015

PAZ004>006-010>012-017>019-037-041-042-045-046-049>053-058-150730-
WARREN-MCKEAN-POTTER-ELK-CAMERON-NORTHERN CLINTON-CLEARFIELD-
NORTHERN CENTRE-SOUTHERN CENTRE-TIOGA-NORTHERN LYCOMING-SULLIVAN-
SOUTHERN CLINTON-SOUTHERN LYCOMING-UNION-SNYDER-MONTOUR-
NORTHUMBERLAND-COLUMBIA-SCHUYLKILL-
317 AM EDT TUE JUL 14 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA.

.DAY ONE...TODAY AND TONIGHT.

SLOW MOVING THUNDERSTORMS COULD CREATE HEAVY DOWNPOURS.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS POSSIBLE.

PAZ024>028-033>036-056-057-059-063>066-150730-
CAMBRIA-BLAIR-HUNTINGDON-MIFFLIN-JUNIATA-SOMERSET-BEDFORD-FULTON-
FRANKLIN-PERRY-DAUPHIN-LEBANON-CUMBERLAND-ADAMS-YORK-LANCASTER-
317 AM EDT TUE JUL 14 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA.

.DAY ONE...TODAY AND TONIGHT.

SLOW MOVING THUNDERSTORMS WILL PRODUCE HEAVY RAIN. THERE IS ALSO A
SLIGHT RISK OF SEVERE THUNDERSTORM WIND DAMAGE AND LARGE HAIL.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL LIKELY BE NEEDED.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
421 AM EDT TUE JUL 14 2015

PAZ057-059-140900-
DAUPHIN PA-LEBANON PA-
421 AM EDT TUE JUL 14 2015

...A THUNDERSTORM WITH VERY HEAVY RAIN WILL AFFECT DAUPHIN AND
LEBANON COUNTIES UNTIL 500 AM EDT...

AT 418 AM EDT...DOPPLER RADAR INDICATED A THUNDERSTORM NEAR
MIDDLETOWN...MOVING NORTHEAST AT ONLY 10 MPH.

VERY HEAVY RAIN IS EXPECTED WITH THIS THUNDERSTORM. HARRISBURG
INTERNATIONAL AIRPORT HAS PICKED UP AROUND AN INCH OF RAIN IN THE
LAST 45 MINUTES.

THE THUNDERSTORM WITH HEAVY RAIN WILL BE NEAR...
  HERSHEY AND LAWN AROUND 450 AM EDT.
  CAMPBELLTOWN AROUND 455 AM EDT.
  PALMYRA...ANNVILLE AND MOUNT GRETNA HEIGHTS AROUND 500 AM EDT.

OTHER LOCATIONS IMPACTED BY THE THUNDERSTORM WITH HEAVY RAIN INCLUDE
AVON HEIGHTS...MOUNT GRETNA...AND ONO.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN URBAN AREAS...SOME MINOR FLOODING MAY DEVELOP. DO NOT DRIVE INTO
WATER COVERING THE ROADWAY.

&&

LAT...LON 4019 7659 4017 7663 4015 7669 4016 7669
      4015 7670 4014 7673 4017 7675 4018 7677
      4025 7683 4055 7654 4031 7623
TIME...MOT...LOC 0818Z 237DEG 10KT 4022 7669

DANGELO