FXUS61 KCTP 110315
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1015 PM EST THU DEC 10 2009
.SYNOPSIS...
STRONG WESTERLY FLOW WILL CREATE COLD WIND CHILLS OVERNIGHT. THE
WINDS SHOULD RELAX BY SATURDAY AS HIGH PRESSURE BUILDS OVER THE
MID ATLANTIC STATES. A WARM FRONT WILL PUSH THROUGH THE AREA
SUNDAY BRINGING SOME LIGHT MIXED PRECIPITATION TO THE AREA...
FOLLOWED BY A COLD FRONT AROUND TUESDAY OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 9 AM FRIDAY MORNING/...
MEAN FLOW KEEPING THE MAIN LAKE ERIE SNOW BAND WAGGLING ONLY
SLIGHTLY SOUTH THEN NORTH OVER THE LAST 6 HRS - AND OVER NRN
CHAUT/CATT COS IN NY. EXPECT THE FLOW TO VEER JUST A BIT MORE TO THE
WEST/SOUTH THRU THE NIGHT...AND THE BAND SHOULD CLIP NRN WARREN
CO...BUT MAY SPARE SRN HALF OF THE CO. KEPT MAINLY SCT SHSN IN
MCKEAN AND POTTER. WITH LOW CONFIDENCE IN LAKE BAND INTRUSION INTO
THE AREA...WILL NOT ISSUE LK EFF ADVSRY ATTM AND WORD IT AS 1-3 IN
WARREN CO.
CLOUDS ALREADY ON THE DECREASE AS THE SUBSIDENCE BEHIND A
MODERATE VORT MAX AND IN ADVANCE OF THE SFC HIGH TO OUR W PRESSES
DRIER AIR DOWN FM ABOVE. LOCAL 12KM WRF SHOWS THIS VERY NICELY. EXPECT
LITTLE CLOUD COVER TO KEEP TEMPS FROM DROPPING OFF...BUT THE WINDS
AND WELL MIXED ATMOS SHOULD TEMPER THE FALL A BIT. STILL...
MAIN CHANGE FOR THE OVERNIGHT WAS TO TAKE A FEW DEGS OFF THE MINS
AS TEMPS NEARING FCST MINS ATTM. THE WINDS SHOULD REMAIN WELL-
ALIGNED IN THE LLVLS...AND THE STRONG/GUSTY/BLUSTERY WINDS WILL
CONTINUE ALL NIGHT. THIS WILL TAKE THE WIND CHILLS WELL BLO 0F IN
THE NW HALF...AND CLOSE TO -20F AT TIMES. KBFD IS ALREADY -10F AND
KJST -5F. THE KIDS MAY BE VERY COLD AT THE BUS STOPS IN THE
MORNING...ESP WITH THE VERY ICY SNOWPACK OUT THERE.
&&
.SHORT TERM /9 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
THE BRISK WEST TO SOUTHWEST LOW LEVEL FLOW WILL KEEP FOCUS OF
MOST INTENSE LAKE EFFECT SNOW NORTH OF THE BORDER FRIDAY...WHERE
THE MOST INTENSE SINGLE LES BAND SHOULD BE AFFECTING WESTERN NY
STATE. WILL NEED TO CONTINUE TO MONITOR ITS EVOLUTION OVERNIGHT
INTO FRIDAY FOR POTENTIAL ADVISORY ISSUANCES OVER WARREN AND
MCKEAN COUNTIES SHOULD IT SNEAK FURTHER SOUTH.
FRIDAY STILL EXPECTED TO BE THE COLDEST DAY YET THIS SEASON...AS
GEFS SHOWING CORE OF COLD PASSING OVR PA WITH -2SD T0 -3SD ENS
MEAN 850 TEMPS OF ARND -18C. EVEN MIXING TO 850MB ONLY RESULTS IN
HIGH TEMPS FROM THE UTEENS NW MTNS...TO NR 30F LOWER SUSQ VALLEY.
A CONTINUED GUSTY WEST WIND WILL MAKE IT FEEL EVEN COLDER...WITH
AFTN WIND CHILLS HOLDING IN THE SINGLE DIGITS AND TEENS. BUFKIT
SOUNDINGS INDICATE FREQUENT GUSTS BTWN 30-35MPH ARE LIKELY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
LAKE EFFECT BAND WILL WEAKEN FRIDAY NIGHT...FINALLY. HIGH
CONFIDENCE THE FIRST HALF OF THE WEEKEND SHOULD REMAIN QUIET WITH
A BUILDING SFC RIDGE PROVIDING ANTI- CYCLONIC FLOW FROM THE TENN
VALLEY NORTH INTO CENTRAL PA THRU SAT. W/NW FLOW WILL
PERSIST...COUPLED WITH A MODERATING THERMAL TROUGH TO -10 DEG C AT
850MB AND EXPECT FLURRIES/LGT SN ACROSS NW MTNS AND WEAK UPSLOPE
CONDS FOR PORTIONS OF THE LAURELS.
TEMPS BEGIN TO MODERATE SAT. ATTM THE FOCUS IS ON DEVELOPMENT OF A
COASTAL LOW BEING ADVERTISED BY SEVERAL GUIDANCE MEMBERS FOR SUN
NGT/MON. SFC RIDGE SHUD PUSH EAST OFF THE COAST AND STEADILY SLIDE
OUT TO SEA...ALLOWING SFC LOW TO FOLLOW IN IT/S WAKE. THE WILDCARD
IS THAT IF THE SFC RIDGE STRENGTHENS...THE SFC LOW MAY TRACK FURTHER
NW ACROSS THE LOWER SUSQ-VALLEY LATE SUN/EARLY MON. IT DOES APPEAR
CONFIDENCE IS HIGH THAT ELEVATED MOISTURE POOLS NORTH ALONG ARRIVAL
OF BNDRY SUN SO HAVE MAINTAINED INCREASING CLOUD COVER. OVERALL THE
EVENT WILL BE LIMITED ON MOISTURE. 0 DEG 850MB ISOTHERM SHUD LIFT
NORTH SUN NGT...WHICH WOULD SUPPORT ONSET OF MOISTURE BEING A BRIEF
PERIOD OF SN/FZRA THEN ALL RA. ACROSS NW MTNS COLD AIR MAY
PERSIST...WITH LGT SN.
CONFIDENCE IS WAINING A BIT IN REGARDS TO MID-WEEK SHORTWAVE
INTENSITY ACROSS THE PLAINS. SEVERAL MODELS STILL HINT AT A CHC FOR
PRECIP ARRIVING TUE/WED AHEAD OF A MID-LVL TROUGH AXIS...AS
COOLER/DRIER AIR RETURNS FOR THE END OF THE WEEK. ATTM FEEL MOISTURE
FROM MID-WEEK SYSTEM WILL BE FOCUSED FURTHER SOUTH ACROSS THE
GULF/SOUTHERN ATLANTIC STATES.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
PERSISTENT CYC OVER-LAKE BLYR FLOW WILL KEEP MVFR/IFR RESTRICTIONS
AT BFD/JST THRU MOST OF THE OVERNIGHT AND FRIDAY. MVFR CIGS AND
BRIEF SNOW SHOWERS WILL BE COMMON OVER THE CENTRAL MOUNTAINS.
VFR CONDITIONS WILL PREVAIL AT MDT.
PRES GRAD BTWN DEPARTING LOW AND SFC HIGH BUILDING EWD FM THE LWR
MS VLY WILL RESULT IN GUSTY WLY SFC WNDS 25-35KTS INTO FRIDAY. WINDS
WILL RELAX BY SATURDAY AS HIGH BUILDS OVER MID ATLANTIC REGION.
WARM AIR WILL TRY TO RETURN ON SUNDAY BRINGING SOME MIXED
PRECIPITATION TO THE REGION...FOLLOWED BY A FEW DRY DAYS AHEAD OF
A COLD FRONT LATER TUESDAY...FOLLOWED BY QUITE COLD CONDITIONS FOR
THE MIDDLE AND END OF NEXT WEEK.
OUTLOOK...
SAT...BCMG VFR.
SUN/MON...MVFR TO IFR IN LIGHT MIXED PRECIPITATION.
TUE...VFR TO MVFR WITH SHSN/RASN ARRIVING AHEAD OF ARCTIC FRONT.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 9 AM EST FRIDAY FOR PAZ004>006-
010>012-017-018-024-033-037-041-042.
&&
$$
SYNOPSIS...DANGELO/DEVOIR
NEAR TERM...DANGELO
SHORT TERM...DEVOIR
LONG TERM...FITZGERALD/BEACHLER
AVIATION...DEVOIR/MARTIN/STEINBUGL
