Monday, July 6, 2015, 10:43 PM EDT
Return to Local
Area Forecast Discussion
Valid At
Mon, Jul 6, 8:05pm EDT
FXUS61 KCTP 070005
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
805 PM EDT MON JUL 6 2015

.SYNOPSIS...
A WEAKENING UPPER LOW WILL TRACK EAST ACROSS THE REGION TONIGHT.
A COLD FRONT WILL APPROACH TUESDAY NIGHT...AND STALL ALONG JUST
SOUTH OF THE MASON DIXON LINE FOR MIDWEEK.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
23Z REGIONAL RADAR LOOP SHOWING CONVECTION DECREASING IN COVERAGE...AS
BLYR BEGINS TO COOL/STABILIZE. WEAK SHEAR AND NON-EXISTENT DCAPES
IMPLY A VERY LOW CHC OF SVR WX. MAIN CONCERN THRU THIS EVENING
CONTINUES TO BE ISOLD FLOODING FROM ANY TRAINING TSRA. WET
GROUND/LOW FFG VALUES MAKE THE AREA ABNORMALLY SUSCEPTIBLE TO
FLASH FLOODING. LATEST HRRR INDICATES THE POTENTIAL OF ISOLD
AMTS OVR 1 INCH BTWN 00Z-06Z. WILL CONTINUE TO HIGHLIGHT FLOOD
POTENTIAL IN THE HWO AND HOLD OFF ON A FFA DUE TO ISOLD NATURE OF
THREAT.

EXPECT SHRA TO DWINDLE W/LOSS OF HEATING AFTER SUNSET. FOCUS OF
REMAINING CONVECTION OVERNIGHT SHOULD BE FOCUSED ALONG REMNANT LL
JET AND PLUME OF GREATEST MOISTURE/INSTABILITY. NEAR TERM MDLS
MOVE THIS FEATURE FROM THE CENTRAL MTNS EARLY THIS EVENING TO 
THE SUSQ VALLEY BY 03Z...THEN EAST OF THE CWA AFTER 06Z. GIVEN
ABUNDANT LOW LVL MOISTURE...TEMPS WILL NOT FALL MUCH OVERNIGHT.
THIS WILL LEAVE THE REGION MUGGY WITH LOWS RUNNING SEVERAL DEG
ABOVE NORMAL.

PARTIAL CLEARING...COMBINED WITH WET GROUND AND A NEARLY CALM WIND
SHOULD RESULT IN AT LEAST PATCHY FOG OVERNIGHT.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
REMNANT UPPER LOW WILL BE PUSHING EAST OF THE AREA TUESDAY...RESULTING
IN A MAINLY RAIN-FREE DAY. WILL MAINTAIN JUST A SLIGHT CHC OF
SHOWERS ACROSS THE EASTERN COUNTIES THRU EARLY PM. WARMING TEMPS
IN THE MID LEVELS WILL HELP LIMIT SHOWERS AND STORMS ACROSS MUCH
OF CENTRAL PA DURING THE PM HOURS. THE EXCEPTION WILL BE THE NW
MTNS...WHERE AN APPROACHING COLD FRONT WILL LKLY PUSH A LINE OF
TSRA INTO THE AREA BY EARLY EVENING. THIS REGION IS CURRENTLY OUTLOOKED
FOR A MARGINAL RISK TUES EVENING.

HIGH TUESDAY WILL LIKELY BE THE WARMEST THIS WEEK...AND ABOUT 3-4
DEG ABOVE NORMAL. 8H TEMPS TEMPS NR 17C SHOULD TRANSLATE TO MAX
TEMPS WELL INTO THE 80S OVER MOST OF CENTRAL PA.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
THE 07/00Z MODEL AND ENSEMBLE GUIDANCE IS PROVIDING A FAIRLY
CONSISTENT SIGNAL THAT THE AREA WILL REMAIN IN A LOW AMPLITUDE
QUASI-ZONAL MID/UPPER FLOW PATTERN WITHIN THE NORTHERN STREAM
WESTERLIES. AS MIGHT BE EXPECTED IN THIS PATTERN...THERE IS LOW
PREDICTABILITY/CONFIDENCE GIVEN DEGREE OF SPREAD AND MEANINGFUL
DIFFERENCES ASSOCIATED WITH SHORTWAVE DETAILS. THIS LARGELY
UNSETTLED AND RECENTLY PERSISTENT WEATHER PATTERN FOR THE LOCAL
AREA WILL BE MODULATED TO SOME EXTENT BY RETROGRESSION OF
UNSEASONABLY STRONG UPPER TROUGH/RIDGE COUPLET OFF THE WEST COAST
AND OVER THE SOUTHEAST AND SCENTRL U.S. THERE IS BROAD SUPPORT FOR
ANOTHER MEAN TROUGH TO DEVELOP OVER THE NORTHEAST/MID ATLANTIC
STATES BY NEXT WEEK/JULY 13TH AS ENERGY EJECTING FROM CA UPPER LOW
EVOLVES DOWNSTREAM IN THE WESTERLIES AND TEAMS WITH VORTEX OVER
HUDSON BAY. 

IN TERMS OF SENSIBLE WEATHER...A WELL-DEFINED COLD FRONT ENTERS
CENTRAL PA EARLY WEDNESDAY ACCOMPANIED BY SHOWERS/TSTMS...THEN
BECOMES WAVY AS IT STALLS OUT FROM NEAR THE OH RIVER/MASON DIXON
LINE. EXPECT ONE OR MORE EPISODES OF PCPN THRU LATE WEEK MOST LKLY
DUE TO MCS REMNANTS OR CONVECTIVELY INDUCED LOWS TRACKING EWD FROM
THE MID MS/OH VLY...BUT TOO DIFFICULT TO PIN POINT TIMING/LOCATION
AT THIS POINT. FWIW THE MODEL BIAS IS USUALLY TOO FAR NORTH WITH
MCS ACTIVITY. PCPN RISK SHOULD EVENTUALLY BE ENHANCED TOWARD THE
END OF THE PERIOD INTO EARLY NEXT WEEK AS CA LOW ENERGY AND
ASSOCIATED SFC SYSTEM REACHES THE GREAT LAKES. 

WHAT WE CAN SAY WITH RELATIVE CERTAINTY IS THAT WE DO NOT EXPECT
ANY HEAT WAVES OR EXTENDED PERIODS OF DRY WEATHER OVER THENEXT 7+
DAYS.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
SENT 00Z TAF PACKAGE.

ADJUSTED TAFS BASED ON CURRENT AND EXPECTED CONDTIONS THE
NEXT FEW HOURS. STILL SOME SHOWERS AND ISOLATED THUNDERSTORMS 
WITH HEAVY DOWNPOURS. LARGEST STORMS SE OF UNV.

EARLIER DISCUSSION BELOW.

CONDITIONS OVER THE STILL MAINLY RAIN FREE LOWER SUSQ
VALLEY...WITH REDUCED CONDITIONS CONTINUING OVER THE LAUREL
HIGHLANDS WHERE SHOWERS ARE MORE NUMEROUS.

EXPECT SHOWER ACTIVITY TO INCREASE IN COVERAGE AND SPREAD FROM
SOUTH TO NORTH THROUGH THE AFTERNOON. SHOWERS WILL TEND TO BE
SLOW-MOVING AND COULD PRODUCE HEAVY DOWNPOURS AND LOCAL IFR
CONDITIONS. THE UPPER LOW WILL WEAKEN AS IT ENTERS CENTRAL PA
OVERNIGHT...BUT WE SHOULD MAINTAIN A RISK FOR SCT SHOWERS.

EXPECT CIGS/VSBYS TO TREND GRADUALLY LOWER OVERNIGHT GIVEN
DIURNAL COOLING...VERY HUMID AIRMASS AND LIGHT WINDS...WITH AT
LEAST MARGINAL RESTRICTIONS LIKELY AT MANY SITES INTO TUESDAY
MORNING.

LOWER CONDITIONS TUESDAY MORNING WILL IMPROVE BY MID MORNING TO
MID DAY. A COLD FRONT WILL APPROACH THE AIRSPACE FROM THE LOWER
LAKES/OH VALLEY BY LATE IN THE DAY AND SHIFT SLOWLY SEWD INTO THE
AIRSPACE TUE NIGHT/WED BEFORE STALLING OUT NEAR PA/MD BORDER
THURS INTO FRIDAY.

OUTLOOK...

WED-SAT...VFR/MVFR WITH PERIODS OF SHRA/AFTN TSTMS.

&&

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

&&

$$
SYNOPSIS...LA CORTE
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD/LA CORTE
LONG TERM...GARTNER/STEINBUGL
AVIATION...LA CORTE/MARTIN

Support USWX by starting your Amazon purchase here.