Area Forecast Discussion
Issued by NWS State College, PA

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000
FXUS61 KCTP 190931
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
531 AM EDT SUN APR 19 2015

.SYNOPSIS...
AN APPROACHING FRONTAL SYSTEM WILL KEEP THE REGION UNSETTLED FROM
TONIGHT THROUGH TUESDAY. A LARGE UPPER LEVEL LOW WILL SET UP OVER
ONTARIO AND QUEBEC FOR THE MIDDLE AND LATTER PART OF THE
WEEK...USHERING IN UNSEASONABLY COOL AIR WHICH WILL LAST INTO THE
WEEKEND OR LONGER.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH CLOUDS THICKEN THROUGH THE DAY AND WILL KEEP TEMPS DOWN
10-15F FROM SATURDAY/S LOFTY VALUES. LATEST MODEL TIMING INCLUDING
THE NAM 06Z RUN SUGGESTS THE BULK OF THE REGION WILL BE DRY FOR
MUCH OF THE DAY...EVEN BACKING OFF/BEING SLOWER WITH ONSET. FAR
SOUTHWESTERN AREAS WILL LIKELY SEE SHOWERS BY/AROUND 4 OR 5 PM.
CENTRAL LOCATIONS MAY SEE RAIN BY NIGHTFALL AS THE PRECIP SPREADS
SLOWLY NORTHEAST. SEE FIRE WX SECTION FOR INFO AS WELL.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
LITTLE TO NO CHANGE WAS NECESSARY FROM THE PREVIOUS FEW FORECAST
CYCLES FOR THIS SHORT TERM PERIOD. THE MAIN CHANGE WAS TO FURTHER
REFINE THE TIMING AND TO SHOW A SLIGHTLY MORE-OBVIOUS 4-6HR BREAK
BETWEEN THE OVERNIGHT/MORNING RAIN AND THE STORMS IN THE
AFTERNOON/EVENING. MINS WILL BE HELD UP AS THE WINDS WILL BE
BREEZY. USUALLY...CENTRAL PA DOES NOT GET STRONG WIND GUSTS DURING
STABLE SERLY FLOW RAIN EVENTS. SO THOUGHTS OF A WIND ADVY WERE
DISCOUNTED RATHER EARLY IN THE FORECAST PROCESS TONIGHT.
HOWEVER...THE STRONG LOW AND MID LEVEL FLOW WILL BUMP THE PWATS
INTO THE 1-1.5 INCH RANGE TONIGHT AND MONDAY. THUS...RAIN COULD BE
HEAVY AT TIMES. WITH THE ADDITIONAL TSRA MON PM...THE
QPF REACHES BETWEEN 0.75 AND 1.25 INCHES OVER A LARGE PORTION OF
THE AREA. BUT THE STREAM FLOWS ARE REALLY LOW AND NO THUNDER
TONIGHT SHOULD TRANSLATE INTO NO FLOOD WORRIES OTHER THAN SOME
PONDING OF WATER ON ROADS AND A FEW SMALL CREEKS AT BANKFULL.
THINGS ARE GROWING NICELY NOW IN THE SE AND EVEN LOCALLY IN HAPPY
VALLEY WHICH SHOULD TAKE UP PLENTY OF WATER COMPARED TO JUST TWO
WEEKS AGO. SPC HAS PLACED ALL OF THE AREA INTO MRGL RISK AND
BROUGHT THE DAY2 SLGT RISK INTO SRN PA...RIGHTFULLY SO. THE BREAK
AND ASSOCIATED BREAKS IN THE CLOUDS/WARM SECTOR ON MONDAY WILL
LEAD TO GOOD HEATING AND THE FRONT/FORCING COMES THROUGH AT AN
OPPORTUNE TIME TO GRAB THE MAX CAPES AND MIN STABILITY. CAPES MAY
BE AROUND 1500J/KG AND LI/S DROP TO -3 TO -5. WIND PROFILES ARE
MAINLY MULTI-CELLULAR - BUT WITH THE WARM FRONT LIKELY CUTTING
THROUGH THE AREA AT THE TIME...WILL NEED TO KEEP AN EYE OUT FOR
ROTATING STORMS - ESPECIALLY IF THEY OCCUR ON OR NEAR LLVL
BOUNDARIES.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
BEHIND THE COLD FRONT MIDWEEK...THE UPPER LOW HANGS AROUND S
CANADA/NEW ENGLAND FOR SEVERAL DAYS KEEPING FAIRLY BRISK W/NW FLOW
ACROSS PA. THIS WILL BRING A STEADY STREAM OF COLDER AIR AS TEMPS
SLOWLY SLIP A BIT LOWER EACH DAY WITH BELOW NORMAL READINGS FOR A
SEVERAL DAY PERIOD LINGERING INTO NEXT WEEKEND. PROXIMITY OF
UPPER LOW WILL ALSO KEEP MENTION OF SCT SHOWERS IN THE FORECAST...
MAINLY DURING THE DAYTIME HOURS. WEDNESDAY MAY HOLD A FAST-MOVING
SHORT-WAVE WHICH COULD PRODUCE WHITE PRECIP - BUT DURING THE
MIDDLE OF THE DAY.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS WILL PREVAIL OVERNIGHT...WITH JUST A VEIL OF
CIRRUS STREAMING OVERHEAD.

VFR CONDITIONS WILL PREVAIL DURING SUNDAY...BUT WITH WINDS AGAIN
INCREASING DURING THE MID MORNING TO EARLY AFTERNOON APPROACHING
SYSTEM. SPEEDS OF 10-15 MPH WITH GUSTS TO 20-25 MPH WILL BECOME
COMMON. MVFR CIGS AND VSBYS WILL LIKELY BEGIN TO SPREAD IN FROM
THE SOUTHWEST BETWEEN 22Z AND 00Z WITH WARM ADVECTION. RAIN WILL
QUICKLY SPREAD IN AFTER 00Z FROM THE SOUTH AND WEST.

LOW-LEVEL WIND SHEAR EXPECTED SUNDAY NIGHT WITH A STRONG SOUTH TO
SOUTHERLY 50-60 KT WIND IN THE 2-4 KFT AGL LAYER. WIDESPREAD POOR
FLYING CONDITIONS /IFR TO LIFR/ EXPECTED TO DEVELOP OVERNIGHT WITH
RAIN OF VARYING INTENSITY SUNDAY NIGHT THROUGH MONDAY AS A
WARM/COLD FRONT COMBINATION MOVES THROUGH THE REGION.

OUTLOOK...

MON...RA TRANSITIONING TO SHRA...ALONG WITH POSSIBLE AFTERNOON
TSRA ASSOCIATED WITH CFP. WIDESPREAD IFR/LIFR IMPROVING TO MORE
SCATTERED RESTRICTIONS IN THE AFTERNOON.

TUE-THU...UNSETTLED WITH NW FLOW...WITH AREAS OF RESTRICTED
CIGS/VSBYS IN SHRA IN THE WESTERN AND NORTHERN MOUNTAINS...SPOTTY
RESTRICTIONS IN MORE SCATTERED SHRA IN CENTRAL MOUNTAINS...AND
MAINLY VFR IN THE EAST AND SOUTHEAST.

&&

.FIRE WEATHER...
WIND WILL BE LIGHT THIS MORNING BUT WILL VEER FROM NORTHEAST TO
MORE SOUTHEASTERLY AND ALSO PICK UP THROUGH THE DAY. WIND GUSTS
BY THE MIDDLE OF THE AFTERNOON WILL BE INTO THE 20S OVER THE WEST.
GUSTS OF 15 TO 20 MPH ARE POSSIBLE IN THE NORTHEAST BY LATE
AFTERNOON. THE RH/S WILL DIP TO 30 PCT FOR AN HOUR OR TWO IN THE
LATE AFTERNOON IN THE NORTH AND NORTHEAST.

BUT THE GUSTS OVER 20MPH WILL ONLY MATCH UP WITH THE LOW RH/S FOR
AN HOUR OR TWO AT THE MOST AND ONLY IN A SMALL PORTION OF THE
NORTHERN MOUNTAINS. WILL HOLD OFF ON A RED FLAG WARNING FOR THE
TIME BEING. BUT IF THE WINDS PICKS UP SOONER IN THE DAY...WE WILL
NEED TO REVISIT THE NEED FOR AN RFW.

A SIGNIFICANT RAINFALL IS EXPECTED STARTING THIS EVENING AND
LASTING UNTIL A COLD FRONT PUSHES THROUGH ON MONDAY AFTERNOON AND
EVENING. COOLER TEMPERATURES FOR THE REST OF THE WEEK WILL LIKELY
LEAD TO HIGHER RH/S AND KEEP FIRE WEATHER CONDITIONS BELOW
CRITICAL.

&&

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

&&

$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...CERU/RXR
AVIATION...JUNG/RXR
FIRE WEATHER...



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