Area Forecast Discussion
Issued by NWS State College, PA

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FXUS61 KCTP 251856
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
256 PM EDT FRI JUL 25 2014

.SYNOPSIS...
HIGH PRESSURE WILL DRIFT EAST ON SATURDAY AND ALLOW THE WEATHER
PATTERN TO BECOME UNSETTLED ONCE AGAIN AS A SERIES OF DISTURBANCES
MOVE OVER THE LATER THIS WEEKEND AND INTO NEXT WEEK. A DEEP UPPER
TROUGH WILL MOVE INTO THE EASTERN UNITED STATES NEXT WEEK AND
BRING ANOTHER SHOT OF UNSEASONABLY COOL TEMPERATURES TO THE
REGION.

&&

.NEAR TERM /UNTIL 11 PM THIS EVENING/...
VERY FEW IF ANY LOW CLOUDS TO DISSIPATE THIS EVENING. EXPECT TEMPS
TO DROP OFF RAPIDLY AFTER SUNSET. HIGH CLOUDS WILL START TO SLIDE
IN FROM THE WEST BY MIDNIGHT...BUT SHOULD NOT GET THICK.

&&

.SHORT TERM /11 PM THIS EVENING THROUGH 6 AM SATURDAY/...
CLOUDS WELL-ALOFT MAY THICKEN UP THROUGH THE NIGHT...BUT ANY LOW
CLOUD DECK AND REAL MOISTURE DOES NOT SHOW UP UNTIL THE DAYTIME ON
SATURDAY. SOME HIGHER MOISTURE DOES SHOW UP OVER THE SE BY
DAYBREAK - SNEAKING IN FROM THE SOUTH. BUT MAINLY WESTERLY FLOW
AT 4-5KFT SHOULD KEEP MOST OF THE HIGHER MOISTURE MOVING TO THE
EAST AND ONLY SLIGHTLY TO THE NORTH. TEMPS SHOULD THEREFORE GET
CHILLY AGAIN...BUT NOT QUITE SO COLD AS FRIDAY MORNING.

&&

.LONG TERM /SATURDAY THROUGH FRIDAY/...
FROM PREVIOUS TEXTS...

SATURDAY WILL START OFF DRY IN MOST AREAS. TIMING AND PLACEMENT
OF EVENTUAL CONVECTION WILL BE VERY DEPENDENT ON UPSTREAM
DEVELOPMENTS AS WE COME UNDER A ROBUST WNW FLOW ALOFT. IN RESPONSE
TO THE APPROACH OF A STRONG UPPER JET STREAK NOSING INTO THE LOWER
LAKES BY LATE IN THE DAY...SHORT RANGE OPERATIONAL MODELS AND
ENSEMBLE PACKAGES AGREE IN DEVELOPING AN ANOMALOUSLY STRONG WSW
LOW LEVEL JET AND SURGING IT INTO THE REGION...ESPECIALLY DURING
SATURDAY AFTERNOON. MOISTURE INITIALLY LOOKS LIMITED...HELPING
TEMPER HOW MUCH INSTABILITY WE WILL EXPERIENCE. I LEANED AWAY
FROM THE VERY WET SREF POPS...USING A BLEND OF MODEL GUIDANCE TO
COME UP WITH JUST A CHANCE OF SHOWERS AND STORMS...THE BETTER
CHANCES BEING IN THE AFTERNOON.

HIGHS SATURDAY WILL BE VERY PLEASANT FROM THE MID 70S NW TO MID 80
SE...BUT DEWPOINTS WILL BEGIN CREEPING UP BRINGING HUMIDITY BACK
INTO THE NOTICEABLE RANGE.

SPC SHOWS A SLIGHT RISK FROM THE CENTRAL PLAINS INTO WESTERN PA
FOR THEIR DAY 2 OUTLOOK. THEY SEEM TO BE KEYING ON A SECONDARY
EVEN STRONGER DISTURBANCE THAT WILL BE DROPPING INTO THE UPPER
MIDWEST...EVENTUALLY SPARKING OFF AN MCS THAT COULD AFFECT THE
AREA LATE SATURDAY NIGHT AND EARLY SUNDAY.

LATEST TIMING HAS SUNDAY BEING SOMEWHAT IN BETWEEN SYSTEMS AS THE
EXPECTED MCS MENTIONED ABOVE FADES AND MAINLY MOVES SOUTH OF THE
REGION. LACKING CONFIDENCE IN PRECIP TIMING OR PLACEMENT...I KEPT
POPS IN THE CHANCE RANGE GIVEN THE STEADILY FALLING UPPER
HEIGHTS...A TAD BELOW MOST GUIDANCE.

HIGHS SUNDAY WILL STILL BE IN THE 70S AND 80S...BUT WILL REPRESENT
A DOWNWARD TREND THAT WE WILL SEE FOR THE UPCOMING WEEK AS AN
ANOMALOUSLY DEEP UPPER TROUGH TAKES AIM AT THE EASTERN US.

BY THE TIME WE GET INTO SUNDAY NIGHT AND MONDAY...THERE ARE
DIFFERENCES IN TIMING AND STRENGTH OF A SURFACE LOW THAT COMES
ALONG WITH THE DEEPENING UPPER SHORTWAVE. THE GFS/GEFS SHOW A
STRONGER SYSTEM AND IMPLY WE COULD BE DEALING WITH A STRONG
MCS/SLUG OF HEAVY RAIN. THE SREF IS LESS DEFINED SINCE THE NAM
WANTS TO BREAK SURFACE DEVELOPMENTS INTO PIECES NW AND SE OF THE
AREA. THE ECMWF IS MORE IN LINE WITH THE GEFS/GFS AND A SINGLE
STRONGER LOW...BUT IS SLOWER. THIS TIMEFRAME SEEMS TO REPRESENT
THE PERIOD OF HIGHEST CONFIDENCE FOR RAINFALL SO LIKELY MOS POPS
LOOK REASONABLE.

BY EARLY NEXT WEEK...A DEEP UPPER TROUGH WILL HELP DELIVER ANOTHER
CHILLY AIRMASS THAT WILL LAST FOR MUCH IF NOT ALL OF THE WEEK.
GEFS SHOWS 500 HEIGHTS SOME 3-4 STD DEV BELOW NORMAL DEVELOPING
AND SETTLING DOWN OVER THE CAROLINAS THROUGH WEDNESDAY...BEFORE
THE TROUGH IS MADE TO BEGIN FILLING AND SLOWLY LIFTING OUT. IT
SHOULD EQUATE TO SEVERAL DAYS WITH LITTLE OR NO RAIN AND
TEMPERATURES RUNNING SEVERAL DEGREES COLDER THAN NORMAL FOR THE
END OF JULY.

&&

.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
VFR CONDITIONS RULING UNDER HIGH PRESSURE. VALLEY FOG IS POSSIBLE
LATE TONIGHT...BUT IT WILL NOT BE QUITE AS COLD AS THIS MORNING.
SO I WILL LEAVE OUT THE MENTION OF FOG FROM THE TAFS AT THIS
POINT. GREAT FLYING CONDITIONS EXPECTED INTO SATURDAY MORNING
WHEN WARM FRONT NEARS FROM THE SOUTH.

MAIN CONCERN WILL BE FROM LATER SATURDAY AFTERNOON...INTO
MONDAY. DURING THIS TIME PERIOD...THE COMBINATION OF DIRECTIONAL
SHEAR...WARM ADVECTION...AND RATHER STRONG DYNAMICS WILL GIVE THE
POTENTIAL FOR WIDESPREAD STRONG TO SEVERE THUNDERSTORMS AND HEAVY
RAIN AS WELL. LLWS MAY BE POSSIBLE ON SATURDAY NIGHT OR SUNDAY.

COOLER WEATHER WILL FOLLOW THE COLD FRONT MONDAY. DIURNAL
CONVECTION IS THEN POSSIBLE UNDER THE COLD POOL ALOFT.

OUTLOOK...

MON...ONCL VIS RESTRICTIONS POSS IN SHRA/TSRA.
TUE-WED...MAINLY VFR. SHRA POSS MTNS.

&&

.CLIMATE...
KBFD TIED THEIR RECORD MIN AT 39F THIS MORNING...THEN SUSEQUENTLY
ROSE 21 DEGREES IN 3 HOURS. WOW. ALL OTHER SITES WERE WITHIN JUST
A FEW DEGREES OF THEIR RESPECTIVE RECORD MINS.

&&

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

&&

$$
SYNOPSIS...DANGELO/LA CORTE
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...LA CORTE
AVIATION...DANGELO/MARTIN
CLIMATE...DANGELO



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